The present invention relates to incubators, and in particular to incubators for neonatal use.

An incubator is an apparatus that is typically used to maintain various environmental conditions suitable for a neonate or new-born baby, and in particular those infants that are born prematurely or those that need additional support to survive. These infants battle to regulate their own body temperature and do not have sufficient fat stores on their body to stay warm. Indeed, in some cases, even full term babies may require incubation treatment.

However, whilst these neonatal incubators are readily available in hospitals throughout most of the Western world, they are cumbersome to transport for use in the field, and are an extremely expensive apparatus, making them unfeasible for use in developing countries. Even in developed countries, there is pressure to provide a simpler, cheaper and more efficient incubator.

There are various forms of incubation that an incubator may be required to perform to help support an infant to develop and grow in a safe environment for the best chance of survival. An incubator, in its most basic form, comprises a shell into which an infant can be placed, that protects the infant from their surrounding environment. This shell shields them from extremes of temperature, draughts and other environmental conditions, whilst minimising infection by limiting their exposure to germs, bacteria and infectious diseases. The shell prevents the ingress of dirt and other detritus that may affect their respiratory airways, whilst also preventing over-handling by carers and other personnel.

There are numerous additional functions that can be added to a basic incubator module to provide additional support to the infant contained therein. The infant may be supplemented with oxygen through an oxygen supply means or mechanical ventilation means. The apparatus might include measuring means for various vital signs such as heart beat, breathing rate, temperature and blood pressure and other measurable bodily functions such as brain activity, blood oxygen levels and cardiac performance. The incubator may include means to provide an effective climate control within the shell to keep the infant at the required temperature. The incubator may also be supplied with nutritional support means through an intravenous catheter or suchlike, to help with administering medications and to help the infant to remain hydrated.

l Neonatal transport incubators provide a similar infant support apparatus when away from a hospital-type environment. They typically provide very similar functionality, just in a transportable form. For an example, a transport incubator might include a miniature ventilator, cardiorespiratory monitor, intravenous therapy pump, pulse oximeter and an oxygen supply means, or any combination of these.

However, whilst these transport incubators would be extremely sought after within the developing world and in disaster relief situations throughout the world, they are an extremely expensive item and the cost renders them unavailable in such areas. Access to incubators is limited by both cost and distance, and millions of premature and sick infants die each year through deaths that may have been prevented had they have had sufficient care. The apparatus that is currently available within these areas is not cheap enough, nor is it sufficiently portable.

A problem faced by medical staff is that of maintaining a sterile environment, particularly when the patient enclosure of an incubator is maintained in a warm (and sometimes moist) state. This is particularly problematic in developing countries, where access to appropriate sanitation may be limited, but even in developed countries medical staff are best placed to focus on patient care, rather than sanitation of equipment.

In addition, the energy required to heat the air for the patient enclosure can be significant. Once more this may be problematic in developing countries, where access to electricity may be limited or sporadic. Even in developed countries, there is a pressure to reduce operational costs.

The present invention aims to address some or all of these drawbacks.

Disclosed herein is a modular incubator comprising: a first end unit; and a patient enclosure having a first portion configured for attaching to the first end unit and a door for accessing the interior of the enclosure, wherein the enclosure is configured to extend away from first end unit, and wherein the first end unit is configured to provide support to the patient enclosure; wherein at least a portion of the patient enclosure is reversibly detachable for sterilisation or disposal. In some cases, there may be two end units, the second end unit for example having some or all of the functionality of the first unit. For example, the functionality of the first end unit as described below may be split between the first and second end units, or it may be duplicated, or some combination of these. By providing a part of the patient enclosure as being reversibly detachable for sterilisation or disposal, the burden on medical staff to ensure that the enclosure is fit for purpose is greatly reduced, and the risk of infection from unclean surroundings is reduced. When it is noticed that the enclosure is no longer clean enough to provide adequate care, it, or the removable parts of it, can be removed and replaced with a sterile part, while the removed portion can be cleaned or disposed of. It is a significantly reduced burden on healthcare to retain a store of removable enclosure parts than to provide suitable cleaning facilities, or entire replacement incubators. In addition, typical cleaning and microbial testing procedures for incubators may take between 45 minutes and 2 hours, for example. The incubator described herein allows for a turnaround time of mere seconds. The actual task of cleaning could, for example be outsourced to an offsite facility. Reversibly detachable as used herein means that the portions in question may be removed from the rest of the assembly without damaging it. Moreover, such portions, or broadly equivalent replacement portions, can be reattached in the same manner as the original portion was attached, again without causing damage. As used herein, the term "configured to extend away from" should be construed to mean that when the patient enclosure is attached to the first unit, the assembled device has an extent that is larger in at least one direction than that of the end unit alone. In other words, while the patient enclosure may be configured so that, during the attachment and assembly process, it expands outwards to form a full-sized enclosure, other designs in which the enclosure is a wholly or partially rigid assembly for attaching to the end unit are also contemplated.

As used herein, "disposable" may mean that the patient enclosure may be lightweight, for example, or made from less durable materials than other incubators, or from relatively thin or soft plastics, for example. Enclosures of this type are only required to last for a week or so prior to replacement, rather than potentially years.

Optionally, the reversibly detachable portion may be an inner liner of the patient enclosure. This allows more of the enclosure to be maintained, and less discarded or sterilised, thereby reducing the environmental impact of replacing the removable portion. The inner liner may cover the entirety of the internal surfaces, or it may cover only some of the internal surfaces in some cases. Additionally, the incubator can be supplied as a complete unit, which requires simply the liner to be fitted. This can speed up the preparation of the incubator. Additionally or alternatively, the entire patient enclosure is reversibly detachable for sterilisation or disposal. In other words, the patient enclosure may be a standalone unit in the sense that the entire enclosure may be separable from the functional portions of the incubator, so that the entire patient enclosure can be supplied separately and can be replaced as a whole unit. For example, the first and/or second portions of the patient enclosure may not have any type of removable insert but instead the enclosure may be a standalone flexible structure that is attached to the end units using a fastening method such as clips, zippers or hooks. This allows medical staff to quickly and easily replace an entire section of the incubator. In addition, the replaceable nature of the patient enclosure means that a single end unit can be used with a variety of enclosures for its lifetime, so for example a selection of enclosures of different sizes can be used to accommodate different aged patients. When both the liner and the entire enclosure are removable, the liner can be replaced regularly without interrupting treatment (i.e. with minimal interference), and the entire enclosure can be replaced between patients, thereby maximising the benefits of having each portion alone being removable.

In the case of the removable portion being an inner liner, it may be reversibly attached to the interior surfaces of the enclosure by way of a hook and look fastening system, releasable adhesive, zips, buttons, clips, poppers, etc., or any other suitable means.

The patient enclosure may be reversibly attachable to the first and/or second end units by virtue of cooperating attachment means on the first portion and the first end unit and/or on the second portion and the second end unit. Examples of suitable attachment means are zips, buttons, poppers, toggles and eyeholes, or various forms of clips, examples of which are described in detail below

The first and/or second portion of the patient enclosure may include a rigid insert. Rigid inserts can help certain portions of the enclosure to retain their shape. Preferably, the insert or inserts comprise planar portions, so that the collapsible, inflatable and/or flexible variants of the design are able to reduce to ta relatively small volume. This can help the patient enclosure to be stored efficiently when not in use, but to still provide a support structure to the enclosure.

The or each rigid insert is provided in a pocket in the first and/or second portion, for example the rigid insert(s) may be removably inserted in a pocket in the first and/or second portion of the enclosure, e.g. held in place by friction, or by a removable closure on the pocket, for example a hook and look fastening system, releasable adhesive, zips, buttons, etc., or the insert may be permanently mounted in the pocked, for example welded in place, or fixed with permanent adhesive.

In some examples, the rigid insert(s) may be permanently affixed to the enclosure itself, without the need for a pocket at all. For example, the rigid portions may be permanently mechanically fixed to the enclosure by screws, rivets, staples and the like. In other examples they may be either formed integrally with the enclosure, or they may be bonded to the enclosure by means of adhesives, welding, or the like. In these latter examples, the rigid material will be made of a compatible material, e.g. one which can be bonded or welded to the material of the enclosure. This may mean that the rigid portion is made from the same material as the enclosure. In other cases, e.g. where the enclosure must be flexible but the inserts must be rigid, it may not be possible to make both from the same material, but a pairing can be chosen by consulting a known list of compatible materials. This rigid portion can help parts of the enclosure to retain their shape. This allows for the reduction in use of material overall for the patient enclosure whilst keeping the rigidity of using an insert.

In some examples, the attachment means on the patient enclosure are provided on the rigid insert. This allows the attachment means to make use of rigid components, while not requiring the entire enclosure to be rigid.

The cooperating attachment means may comprise one or more of: buttons and holes; toggles; and/or clips. Many of the attachment means suitable for use in this situation are described in detail below.

In other examples, the cooperating attachment means comprise a rigid lip on one or both of the end units and a flexible region of the patient enclosure at one or both of the first and second portions for stretching over the or each lip. Thus by simply stretching the first and/or second portions over the lip, a connection can be made, without any complex moving parts. To assist with the attachment, the or each flexible region may be formed from an elastic material.

One or more of: air supply; air heaters; power supply; water supply; temperature probes; attachments for weigh scales; X-ray tables; and/or air filters may optionally be housed in the first and/or second end unit. This allows the active parts of the incubator system (e.g. for supplying and maintaining the desired environmental conditions) to be kept separate from the patient enclosure. Since some or all of the enclosure is removable, this can help to ensure that the more delicate and expensive components are kept out of harm's way.

The patient enclosure may be collapsible, such that it is configurable in an expanded configuration, and a collapsed configuration, wherein the expanded configuration occupies more space than the collapsed configuration. This allows the disposable portions of the incubator system to be supplied and stored in the collapsed configuration, to save space, and promote efficient transport, without diminishing the space available for patient care. In the expanded configuration, the first and second portions may face one another. This provides a convenient shape for the patient enclosure.

The patient enclosure may be flexible, and/or inflatable. This vastly simplifies the transition between expanded and collapsed configurations. Optionally, the patient enclosure may comprise a double walled construction, for example.

The modular incubator optionally includes a humidification means. It is often desirable to control the humidity of the air inside an incubator, in order to provide the best environment for the patient. An example of humidification means is a container of sterile water. This container may be placed (or mounted) in the patient enclosure to provide a steady amount of humidity. Such a container of sterile water may be removable from the patient enclosure, for example, so that it is only present in cases where increased humidity is desirable. Indeed, containers of this type can be supplied separately from the rest of the incubator, and mounted in the enclosure only when needed. This reduces unnecessary waste by only providing humidity means when required. The container of sterile water may include a removable cap for controlling whether humidification of the patient enclosure occurs. This means that the container can be left in place until such time as humidity is deemed desirable, without prematurely humidifying the enclosure.

Advantageously, the container of sterile water may include a permeable cover for controlling the amount of humidification supplied to the patient enclosure. The cover may hinder the release of moisture to provide humidity at a controlled level. For example, the cover may be provided underneath the removable cap (where present), and the cover may be either removable or permanently attached. The cover itself may be made of a porous or perforated material, which acts to change the surface area of water exposed to the environment relative to a simple open container. A porous material may increase the surface area by adsorption of the moisture on the material, while a perforated material may reduce the surface area by blocking the evaporation path of the water.

The exact change in release rate can be tailored to meet healthcare guidelines for specific situations. For example, in the case where the water container is removable from the enclosure, the containers for fitting into the enclosure can be supplied in a graded series which provide progressively more humidity to the enclosure. In the event that a particular humidity level is required, the appropriate container can be selected and fitted into the enclosure.

In another example, the cover may be removable, and a series of covers may be supplied with the containers, each corresponding to a different humidity level. For example, each of the covers may have a different permeability, and may correspond to a different level of humidity in the patient enclosure. When a particular level of humidity is required, the appropriate cover can be selected and fit to the container which is itself mounted in the enclosure. The covers can even be reusable, to further reduce waste.

Another example of a suitable humidification means comprises a water supply connected to a controllable humidifier. This may be located inside the enclosure, or coupled to an air supply to the interior of the enclosure to deliver already humid air to the enclosure. The exact level of humidity can be closely controlled in this manner.

The above examples may each be provided with an on board water supply. The water supply may be refillable, but in any case, the capacity of the on board water supply may be configured to match that of the expected duration of the patient enclosure before the enclosure (or a portion thereof) is replaced. For example the water supply may be arranged to last for a week.

In each case, the rate of release of moisture may not be constant, but may change over time. For example, it is common for neonatal babies to require a higher level of humidity initially, which decreases with time as the baby ages. When the design is the container version, rather than requiring staff to regularly replace the cover, this could be achieved using a tapered container, for example, in which the surface area of the water in the container changes as the water level drops, thereby changing the release rate of humidity into the air. In the case of the controllable humidifier, a programming function could be used to ensure that the rate of humidification is appropriate, possibly in conjunction with the use of feedback, set points, and sensors to detect the humidity and control the humidifier. The amount of humidity is usually determined by a medical professional, but may be up to 95%. A useful range of humidity to provide in the enclosure could be between 30% and 95%, for example by providing a series of covers as set out above, graduated in 5% increments. The provision of humidification means for the patient enclosure may be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided a humidifier for use in an incubator, comprising a water source and a means for vaporising the water source. Optionally, the means for vaporising may be electrical, or a wick, sponge or exposed surface area of the water, for example any of those means discussed above. Optionally, the various means for controlling the timing and quantity of humidity described above are applied to the stand alone humidifier.

In some examples, the incubator functionality is housed in the first end unit and the patent enclosure is reversibly detachable from the first end unit, and the modular incubator includes couplings for connecting the patient enclosure to the first end unit and the incubator functionality is configured to supply one or more of: electrical power; heated air; and/or water to the patient enclosure via the couplings when the first portion is detached from the first end unit. In this context, incubator functionality means the active components of the incubator, such as those for generating and/or supplying warm air, air pressure, water, power, etc. to the interior of the patient enclosure. Arranging the modular incubator in this manner provides resilience against damage from medical scanning machines, while they are in use. For example, MRI machines use strong magnetic fields, which can damage electrical equipment, introduce interference into electrical monitoring systems, and strongly attract ferromagnetic materials, which can cause damage to the structure of devices if they are suddenly pulled towards the MRI scanner (possibly impacting the scanner at speed). Similarly, CT scanners use large doses of X-rays, which can damage electronics and affect electronic read outs.

The provision of couplings for retaining supply of air pressure, warm air, water, power, etc. to the patient enclosure when it is detached may be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided an incubator comprising: a detachable patient enclosure; a first unit comprising components for generating and/or supplying warm air, air pressure, water and/or electrical power to the interior of the patient enclosure; and one or more couplings for connecting the patient enclosure to the first end unit; wherein the couplings are configured to supply the patient enclosure with warm air, air pressure, water and/or electrical power when the first portion is detached from the first end unit.

In any of the above examples, the door may generally rectangular and is hinged along one edge and also hinged along a line across the generally rectangular shape of the door. This allows the door to be opened in two parts, for example, the hinge along one edge may be used to create a large opening to allow a patient to be placed into the enclosure. During the patient's time in the incubator, it is important that the warm environment is not disturbed. Therefore, when routine checks are required, the hinge which operates across the face of the door may be used, which makes a smaller gap, and thus reduces unnecessary air loss, while still providing a sufficient gap for the hands of medical staff to carry out any tasks necessary.

Such a door can be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided a door for an incubator, wherein the door is generally rectangular and is hinged along one edge for hingedly attaching to an incubator and wherein the door is also hinged along a line across the generally rectangular shape of the door. In some examples, the first and/or second end unit comprises a fan and/or a heater removably mounted on a break out board. Fans and heaters are critical components in incubators, and if they fail the incubator quickly becomes ineffective. By mounting the fan and/or heater on a break out board (for example both on the same board, or each on its own board), any fault can be quickly assessed and corrected. In simple cases, the solution may be to repair the problem in situ. In more complex cases, the whole board can be switched out for a new one. Similar faults in known incubators would require at best a lengthy dismantling and repair process, but more commonly replacement of the entire incubator or returning the entire incubator to the manufacturer for repair. Similarly, other components, such as air filters, may be provided in an easily removable manner, for example on a slide rack. For ease of cleaning and repair, the housing of a water supply may form an easy to extract unit. In each case, the replacement of these elements is greatly simplified by mounting them on a quick release extraction system. Optionally, the modular incubator further comprises an IV line holder inside the patient enclosure. Typical solutions for holding IV lines need to be added to incubator units after their manufacture, presenting a risk that the attachment is not strong enough. Equally, loose attachments may cause the holder to fall off, and get lost, increasing upkeep expenses. By providing one or more IV lines as part of the incubator, for example moulded as part of the patient enclosure or the end units, a relatively cost effective means is provided for securely mounting IV lines to the incubator. In addition, IV line holders should be cleaned and sterilised between uses. In other incubator designs, this can be a complicated process. In the present apparatus, the IV lines can be removed when the patient enclosure (or part thereof) is detached, and disposed of or sterilised as part of the process, while a new enclosure is fitted. This can greatly speed up the turnaround time of an incubator between patients. The IV lines may be supplied clipped to the patient enclosure, or indeed they may even be moulded as part of the manufacturing process of the enclosure. As a further development, the incubator may include a hole for receiving an IV line in one of the end units or in the patient enclosure. This allows the IV line to enter the enclosure without allowing too much air to escape. Many holes of different sizes could be provided, for different purposes. In some cases, the hole for receiving an IV line includes a cover for blocking the hole when an IV line is not received in the hole. This prevents unnecessary leaks of the carefully controlled environment when the IV hole(s) are not in use.

The modular incubator may further be provided with means for reversibly mounting the modular incubator on a hospital bed or trolley, for example one or more of: straps; clips; and/or clamps. This allows the incubator to be placed securely on existing hospital equipment, for convenient monitoring.

Many incubation systems generate warm air, and deliver it directly to the patient enclosure. However, this risks inhomogeneities in the temperature distribution. It can be beneficial for the warmed air to be used to warm the walls of the patient enclosure prior to entering the first chamber. By forcing the air path to include portions which run through an air path bounded by at least part of an internal wall of the first chamber, the temperature distribution is improved, due to heating through the walls. Various solutions to the problem of how to efficiently heat the chamber in this way are presented herein.

In some cases the patient enclosure comprises: a first chamber for receiving a patient, the first chamber being defined by one or more walls and having a first end and a second end opposing the first end; and a second chamber defined by one or more walls, at least one wall of the second chamber being arranged adjacent to a wall of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap located at or adjacent to the first end of the first chamber; and one or more apertures located at or adjacent to the second end of the first chamber wherein the or each aperture fluidly connects the air gap to the interior of the first chamber; and wherein each aperture is located at or adjacent to the second end of the first chamber, so that an air flow path from the inlet to the interior of the first chamber traverses a portion of the air gap between the first and second ends of the first chamber. By forcing the air to follow a flow path between the two ends, the warmed air spends a significant amount of time next to the exterior walls of the first chamber, improving the warming effect. In the above description, the two ends broadly represent the maximum extent of the first chamber in opposite directions along an axis, i.e. along a particular direction in 3D space (for example length, width or height of the first chamber) along which the first chamber extends. Where the apertures or inlet are adjacent to the first or second end, this means that they are located substantially at the same location as that end. This does not mean that they must be located exactly at the furthest extent of the inner chamber at that location (i.e. exactly at the end), but that every one of the apertures is located close to the furthest extent, for example within 10% of the distance between the total length in that direction. This has the effect, for example, that the air flow path extends along substantially the entire extent in that direction for the same reasons. Where each aperture is described as being located at or adjacent the second end of the first chamber, this does not preclude other apertures being present for other reasons. For example, as set out above, there may be doors or IV holes, which can be used to create a hole into the inner chamber (e.g. for placing a patient inside, or for inserting an IV line). These holes are intended to be negligibly small (in the case of IV lines) or closable (in the case of both the door and some examples of IV lines) to leave substantially no hole during the normal operation of the incubator. The description of apertures above should therefore be interpreted as referring only to the apertures specifically connecting the air gap to the interior of the first chamber for the purposes of allowing air flow as described above.

Another example of a solution to the same problem is a first chamber for receiving a patient, the first chamber being defined by one or more walls; and a second chamber defined by one or more walls, at least one of walls of the second chamber arranged adjacent to one of the one or more walls of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap; a plurality of apertures fluidly connecting the air gap to the interior of the first chamber including at least two different aperture sizes; and wherein the inlet and the aperture are spaced apart from one another so that an air flow path from the inlet to the interior of the first chamber includes traversing a portion of the air gap and wherein smaller apertures are located closer than larger apertures to the inlet. A system such as this has the advantage that warm air enters all along the surface, thus improving the distribution of warm air inside the patient enclosure. Arranging the apertures such that the smallest apertures are closest to the inlet and the largest are furthest away reduces the amount of warm air which enters the patient enclosure close to the inlet, and forces the air to spend more time traversing the exterior of the patient enclosure to achieve the warming effect set out above. In the event that there are more than two sizes of aperture, the general concept can be followed, meaning that the smallest apertures are the ones closest to the inlet, the next smallest are the next closest, and so on until the largest apertures are located the furthest from the inlet. That is, each aperture is larger than the apertures to one side of it (if any) and smaller than the apertures on the other side of it (if any). For the avoidance of doubt, there can be multiple apertures of the same size located approximately the same distance from the inlet. These examples can be seen to be very closely linked solutions, since in each case the largest apertures are the furthest from the inlet. In the first example, these apertures are the only apertures, so they are the largest by definition. In the second example, the apertures are arranged to become progressively larger the further they are from the inlet. In either case, the effect is to retain the air in the air gap for longer before it enters the interior of the first chamber.

The second chamber may at least partially enclose the first chamber. In some cases, the air gap at least partially surrounds the first chamber. This may allow for a larger air flow path.

In many examples, there is a plurality of apertures spaced around the one or more walls of the first chamber. In this case, the plurality of apertures helps to spread the warmth evenly throughout the first chamber.

In some cases the first and second chambers are flexible, collapsible, or are configured such that the air gap inflates when positive pressure is supplied to the inlet. This provides the advantages set out above in respect of a flexible, inflatable or collapsible patient enclosure, when both chambers have that property.

Optionally, the walls of the first chamber include upper and lower surfaces, two side walls and first and second end walls arranged in a generally cuboidal shape. This is a convenient shape for transporting and stacking, as well as for housing a patient.

There are many possible air flow paths in such a system. For example, the air flow path may include a portion of the air gap adjacent to the lower surface of the first chamber. This results in a first chamber which is easier to clean. Alternatively or additionally, the air flow path can include a portion of the air gap adjacent to the upper surface of the first chamber. This provides a desirable thermal gradient in the first chamber. In yet more examples, the air flow path may additionally or alternatively include a portion of the air gap adjacent to one or both of the side walls of the first chamber. Such an arrangement may be simpler to manufacture than other designs. In some cases the or at least one of the apertures is located in the first end wall and the inlet is located adjacent to the second end wall. This forces the warm air to traverse an entire outer surface of the first chamber before it enters the first chamber. This helps to warm the entire chamber through at least one of the walls, prior to entering, providing more even heating.

The or each of the plurality of apertures may be located in the lower surface of the inner enclosure. In other examples, the or each of the plurality of apertures may be located in the upper surface of the inner enclosure. As set out above, this provides a desirable thermal gradient in the first enclosure. In still more examples, the or each of the plurality of apertures is located in one or both of the side walls of the first chamber. In some cases, the incubator further comprises an outlet from the patient enclosure for allowing air to flow out from the interior of the patient enclosure. This can prevent a buildup of excess pressure in the patient enclosure. In some cases, the outlet is connected to a heater and fan for recirculating air leaving the first chamber through the outlet. By recirculating the air, much of the warmth can be retained, improving operational efficiency. A blend of fresh, cool air with recirculated air can be used to ensure a sufficient supply of oxygen. The inventors have found a wide range of mixtures to be suitable. An efficient mixture may use at least half recycled air, and even up to 95% recirculated. A mix of about 90% recirculated with about 10% fresh is particularly suitable. The patient enclosure may further include air circulation vents. These come in the form of perforations or other apertures in the patient enclosure. In the event that the air supply (e.g. a fan) fails, fresh (i.e. oxygenated, temperature- and humidity-controlled, etc.) air is no longer delivered to the interior of the patient enclosure. Therefore, one or more vents may be provided to connect the interior of the enclosure to the outside world, thereby allowing fresh air in, in the event of such a fan failure or other air supply issue. Put another way, these air circulation holes (i.e. the vents) are included in patient enclosure to allow for air to flow in and out passively. The air circulation holes mean that if all power is lost to the incubator then the holes act as a safety mechanism so that the patient always has access to oxygenated air in any type of scenario.

While any location on the exterior of the patient enclosure is suitable for vent placement, some locations are preferred. For example, where the enclosure is largely flexible with rigid portions, the vents can advantageously be provided in the rigid portions. This is because if the flexible portion collapses, the vents are more likely to remain open if they are in the rigid portion, but may become blocked by the collapsing flexible portion if they are located in the flexible portion. In some cases, the vents may be located in parts of the enclosure to which it is otherwise difficult to ensure air flow. For example, in the hypothetical example that it is found that a corner region of a cuboidal enclosure receives less air than other parts of the enclosure, yet air is desired in that region, then a vent may be placed in that corner region so that air flows through the region as it leaks out of the vent.

Any such air circulation vents should be sized and shaped so as to ensure that they do not disrupt existing air flow paths. For example, a large hole would cause a leak out of the enclosure and greatly reduce the ability of the incubator to provide a climate-controlled environment. Even where the vents are part of the flow paths, as set out above, too large a hole can reduce the temperature to an unacceptable degree. Conversely, if the vent is too small, the beneficial effects may not be provided sufficiently to ensure patient safety. Multiple vents may be used in some cases, to ensure that the correct balance is struck. Depending on the size and shape of the enclosure, a variety of vent sizes and locations may be beneficially chosen to achieve the desired balance. It is within the skilled person's skills to determine a suitable vent distribution, sizing and shape for a given design, without undue experimentation.

Another manner in which the air flow paths may be preserved is to fit the vents with one-way flow elements (e.g. valves). These would be configured to allow air flow into the enclosure, but not out. Since there is air flow into the interior of the enclosure in normal operation, the enclosure operates at a slight positive pressure. This means that such oneway elements on the vents would be held shut, and no air would flow out of them. In the event of a fan failure, no positive pressure condition exists and the valves would open, thereby fulfilling their safety function. In some designs which use this idea, only some of the vents may be fit with one-way flow elements. In other such designs all of the vents may be provided with one-way air flow elements.

Also disclosed herein is a kit of parts for the assembly of a modular incubator. The kit of parts may comprise some or all of the various components described above, in a disassembled, or partially assembled, state. More specifically, described herein is a kit of parts for the assembly of a modular insulator, the kit of parts comprising: a first end unit; and a patient enclosure having a first portion configured for attaching to the first end unit and a door for accessing the interior of the enclosure, wherein the enclosure is configured to extend away from first end unit, and wherein the first end unit is configured to provide support to the patient enclosure; wherein at least a portion of the patient enclosure is reversibly detachable for sterilisation or disposal. In some cases, there may be two end units, the second end unit for example having some or all of the functionality of the first unit. For example, the functionality of the first end unit as described below may be split between the first and second end units, or it may be duplicated, or some combination of these. By providing a part of the patient enclosure as being reversibly detachable for sterilisation or disposal, the burden on medical staff to ensure that the enclosure is fit for purpose is greatly reduced, and the risk of infection from unclean surroundings is reduced. When it is noticed that the enclosure is no longer clean enough to provide adequate care, it, or the removable parts of it, can be removed and replaced with a sterile part, while the removed portion can be cleaned or disposed of. It is a significantly reduced burden on healthcare to retain a store of removable enclosure parts than to provide suitable cleaning facilities, or entire replacement incubators. In addition, typical cleaning and microbial testing procedures for incubators may take between 45 minutes and 2 hours, for example. The incubator described herein allows for a turnaround time of mere seconds. The actual task of cleaning could, for example be outsourced to an offsite facility. Reversibly detachable as used herein means that the portions in question may be removed from the rest of the assembly without damaging it. Moreover, such portions, or broadly equivalent replacement portions, can be reattached in the same manner as the original portion was attached, again without causing damage. As used herein, the term "configured to extend away from" should be construed to mean that when the patient enclosure is attached to the first unit, the assembled device has an extent that is larger in at least one direction than that of the end unit alone. In other words, while the patient enclosure may be configured so that, during the attachment and assembly process, it expands outwards to form a full-sized enclosure, other designs in which the enclosure is a wholly or partially rigid assembly for attaching to the end unit are also contemplated. As used herein, "disposable" may mean that the patient enclosure may be lightweight, for example, or made from less durable materials than other incubators, or from relatively thin or soft plastics, for example. Enclosures of this type are only required to last for a week or so prior to replacement, rather than potentially years. Optionally, the reversibly detachable portion may be an inner liner of the patient enclosure. This allows more of the enclosure to be maintained, and less discarded or sterilised, thereby reducing the environmental impact of replacing the removable portion. The inner liner may cover the entirety of the internal surfaces, or it may cover only some of the internal surfaces in some cases. Additionally, the incubator can be supplied as a complete unit, which requires simply the liner to be fitted. This can speed up the preparation of the incubator. Additionally or alternatively, the entire patient enclosure is reversibly detachable for sterilisation or disposal. In other words, the patient enclosure may be a standalone unit in the sense that the entire enclosure may be separable from the functional portions of the incubator, so that the entire patient enclosure can be supplied separately and can be replaced as a whole unit. For example, the first and/or second portions of the patient enclosure may not have any type of removable insert but instead the enclosure may be a standalone flexible structure that is attached to the end units using a fastening method such as clips, zippers or hooks. In addition, the replaceable nature of the patient enclosure means that a single end unit can be used with a variety of enclosures for its lifetime, so for example a selection of enclosures of different sizes can be used to accommodate different aged patients. This allows medical staff to quickly and easily replace an entire section of the incubator. When both the liner and the entire enclosure are removable, the liner can be replaced regularly without interrupting treatment (i.e. with minimal interference), and the entire enclosure can be replaced between patients, thereby maximising the benefits of having each portion alone being removable. In the case of the removable portion being an inner liner, it may be reversibly attached to the interior surfaces of the enclosure by way of a hook and look fastening system, releasable adhesive, zips, buttons, clips, poppers, etc., or any other suitable means.

The patient enclosure may be reversibly attachable to the first and/or second end units by virtue of cooperating attachment means on the first portion and the first end unit and/or on the second portion and the second end unit. Examples of suitable attachment means are zips, buttons, poppers, toggles and eyeholes, or various forms of clips, examples of which are described in detail below The first and/or second portion of the patient enclosure may include a rigid insert.

Rigid inserts can help certain portions of the enclosure to retain their shape. Preferably, the insert or inserts comprise planar portions, so that the collapsible, inflatable and/or flexible variants of the design are able to reduce to ta relatively small volume. This can help the patient enclosure to be stored efficiently when not in use, but to still provide a support structure to the enclosure.

The or each rigid insert is provided in a pocket in the first and/or second portion, for example the rigid insert(s) may be removably inserted in a pocket in the first and/or second portion of the enclosure, e.g. held in place by friction, or by a removable closure on the pocket, for example a hook and look fastening system, releasable adhesive, zips, buttons, etc., or the insert may be permanently mounted in the pocked, for example welded in place, or fixed with permanent adhesive. In some examples, the rigid insert(s) may be permanently affixed to the enclosure itself, without the need for a pocket at all. For example, the rigid portions may be permanently mechanically fixed to the enclosure by screws, rivets, staples and the like. In other examples they may be either formed integrally with the enclosure, or they may be bonded to the enclosure by means of adhesives, welding, or the like. In these latter examples, the rigid material will be made of a compatible material, e.g. one which can be bonded or welded to the material of the enclosure. This may mean that the rigid portion is made from the same material as the enclosure. In other cases, e.g. where the enclosure must be flexible but the inserts must be rigid, it may not be possible to make both from the same material, but a pairing can be chosen by consulting a known list of compatible materials. This rigid portion can help parts of the enclosure to retain their shape. This allows for the reduction in use of material overall for the patient enclosure whilst keeping the rigidity of using an insert.

In some examples, the attachment means on the patient enclosure are provided on the rigid insert. This allows the attachment means to make use of rigid components, while not requiring the entire enclosure to be rigid. The cooperating attachment means may comprise one or more of: buttons and holes; toggles; and/or clips. Many of the attachment means suitable for use in this situation are described in detail below.

In other examples, the cooperating attachment means comprise a rigid lip on one or both of the end units and a flexible region of the patient enclosure at one or both of the first and second portions for stretching over the or each lip. Thus by simply stretching the first and/or second portions over the lip, a connection can be made, without any complex moving parts. To assist with the attachment, the or each flexible region may be formed from an elastic material.

One or more of: air supply; air heaters; power supply; water supply; temperature probes; attachments for weigh scales; X-ray tables; and/or air filters may optionally be housed in the first and/or second end unit. This allows the active parts of the incubator system (e.g. for supplying and maintaining the desired environmental conditions) to be kept separate from the patient enclosure. Since some or all of the enclosure is removable, this can help to ensure that the more delicate and expensive components are kept out of harm's way. The patient enclosure may be collapsible, such that it is configurable in an expanded configuration, and a collapsed configuration, wherein the expanded configuration occupies more space than the collapsed configuration. This allows the disposable portions of the incubator system to be supplied and stored in the collapsed configuration, to save space, and promote efficient transport, without diminishing the space available for patient care. In the expanded configuration, the first and second portions may face one another. This provides a convenient shape for the patient enclosure. The patient enclosure may be flexible, and/or inflatable. This vastly simplifies the transition between expanded and collapsed configurations. Optionally, the patient enclosure may comprise a double walled construction, for example.

The kit of parts optionally includes a humidification means. It is often desirable to control the humidity of the air inside an incubator, in order to provide the best environment for the patient. An example of humidification means is a container of sterile water. This container may be placed (or mounted) in the patient enclosure to provide a steady amount of humidity. Such a container of sterile water may be removable from the patient enclosure, for example, so that it is only present in cases where increased humidity is desirable. Indeed, containers of this type can be supplied separately from the rest of the incubator, and mounted in the enclosure only when needed. This reduces unnecessary waste by only providing humidity means when required. The container of sterile water may include a removable cap for controlling whether humidification of the patient enclosure occurs. This means that the container can be left in place until such time as humidity is deemed desirable, without prematurely humidifying the enclosure.

Advantageously, the container of sterile water may include a permeable cover for controlling the amount of humidification supplied to the patient enclosure. The cover may hinder the release of moisture to provide humidity at a controlled level. For example, the cover may be provided underneath the removable cap (where present), and the cover may be either removable or permanently attached. The cover itself may be made of a porous or perforated material, which acts to change the surface area of water exposed to the environment relative to a simple open container. A porous material may increase the surface area by adsorption of the moisture on the material, while a perforated material may reduce the surface area by blocking the evaporation path of the water. The exact change in release rate can be tailored to meet healthcare guidelines for specific situations. For example, in the case where the water container is removable from the enclosure, the containers for fitting into the enclosure can be supplied in a graded series which provide progressively more humidity to the enclosure. In the event that a particular humidity level is required, the appropriate container can be selected and fitted into the enclosure.

In another example, the cover may be removable, and a series of covers may be supplied with the containers, each corresponding to a different humidity level. For example, each of the covers may have a different permeability, and may correspond to a different level of humidity in the patient enclosure. When a particular level of humidity is required, the appropriate cover can be selected and fit to the container which is itself mounted in the enclosure. The covers can even be reusable, to further reduce waste. Another example of a suitable humidification means comprises a water supply connected to a controllable humidifier. This may be located inside the enclosure, or coupled to an air supply to the interior of the enclosure to deliver already humid air to the enclosure. The exact level of humidity can be closely controlled in this manner. The above examples may each be provided with an on board water supply. The water supply may be refillable, but in any case, the capacity of the on board water supply may be configured to match that of the expected duration of the patient enclosure before the enclosure (or a portion thereof) is replaced. For example the water supply may be arranged to last for a week.

In each case, the rate of release of moisture may not be constant, but may change over time. For example, it is common for neonatal babies to require a higher level of humidity initially, which decreases with time as the baby ages. When the design is the container version, rather than requiring staff to regularly replace the cover, this could be achieved using a tapered container, for example, in which the surface area of the water in the container changes as the water level drops, thereby changing the release rate of humidity into the air. In the case of the controllable humidifier, a programming function could be used to ensure that the rate of humidification is appropriate, possibly in conjunction with the use of feedback, set points, and sensors to detect the humidity and control the humidifier. The amount of humidity is usually determined by a medical professional, but may be up to 95%. A useful range of humidity to provide in the enclosure could be between 30% and 95%, for example by providing a series of covers as set out above, graduated in 5% increments. The provision of humidification means for the patient enclosure may be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided a humidifier for use in an incubator, comprising a water source and a means for vaporising the water source. Optionally, the means for vaporising may be electrical, or a wick, sponge or exposed surface area of the water, for example any of those means discussed above. Optionally, the various means for controlling the timing and quantity of humidity described above are applied to the stand alone humidifier. In some examples, the incubator functionality is housed in the first end unit and the patent enclosure is reversibly detachable from the first end unit, and the kit of parts incubator includes couplings for connecting the patient enclosure to the first end unit and the incubator functionality is configured to supply one or more of: electrical power; heated air; and/or water to the patient enclosure via the couplings when the first portion is detached from the first end unit. In this context, incubator functionality means the active components of the incubator, such as those for generating and/or supplying warm air, air pressure, water, power, etc. to the interior of the patient enclosure. Arranging the kit of parts in this manner provides resilience against damage from medical scanning machines, while they are in use. For example, MRI machines use strong magnetic fields, which can damage electrical equipment, introduce interference into electrical monitoring systems, and strongly attract ferromagnetic materials, which can cause damage to the structure of devices if they are suddenly pulled towards the MRI scanner (possibly impacting the scanner at speed). Similarly, CT scanners use large doses of X-rays, which can damage electronics and affect electronic read outs. The provision of couplings for retaining supply of air pressure, warm air, water, power, etc. to the patient enclosure when it is detached may be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided an incubator comprising: a detachable patient enclosure; a first unit comprising components for generating and/or supplying warm air, air pressure, water and/or electrical power to the interior of the patient enclosure; and one or more couplings for connecting the patient enclosure to the first end unit; wherein the couplings are configured to supply the patient enclosure with warm air, air pressure, water and/or electrical power when the first portion is detached from the first end unit. In any of the above examples, the door may generally rectangular and is hinged along one edge and also hinged along a line across the generally rectangular shape of the door. This allows the door to be opened in two parts, for example, the hinge along one edge may be used to create a large opening to allow a patient to be placed into the enclosure. During the patient's time in the incubator, it is important that the warm environment is not disturbed. Therefore, when routine checks are required, the hinge which operates across the face of the door may be used, which makes a smaller gap, and thus reduces unnecessary air loss, while still providing a sufficient gap for the hands of medical staff to carry out any tasks necessary.

Such a door can be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided a door for an incubator, wherein the door is generally rectangular and is hinged along one edge for hingedly attaching to an incubator and wherein the door is also hinged along a line across the generally rectangular shape of the door.

In some examples, the first and/or second end unit comprises a fan and/or a heater removably mounted on a break out board. Fans and heaters are critical components in incubators, and if they fail the incubator quickly becomes ineffective. By mounting the fan and/or heater on a break out board (for example both on the same board, or each on its own board), any fault can be quickly assessed and corrected. In simple cases, the solution may be to repair the problem in situ. In more complex cases, the whole board can be switched out for a new one. Similar faults in known incubators would require at best a lengthy dismantling and repair process, but more commonly replacement of the entire incubator or returning the entire incubator to the manufacturer for repair.

Optionally, the system further comprises an IV line holder inside the patient enclosure. Typical solutions for holding IV lines need to be added to incubator units after their manufacture, presenting a risk that the attachment is not strong enough. Equally, loose attachments may cause the holder to fall off, and get lost, increasing upkeep expenses. By providing one or more IV lines as part of the incubator, for example moulded as part of the patient enclosure or the end units, a relatively cost effective means is provided for securely mounting IV lines to the incubator. In addition, IV line holders should be cleaned and sterilised between uses. In other incubator designs, this can be a complicated process. In the present apparatus, the IV lines can be removed when the patient enclosure (or part thereof) is detached, and disposed of or sterilised as part of the process, while a new enclosure is fitted. This can greatly speed up the turnaround time of an incubator between patients. The IV lines may be supplied clipped to the patient enclosure, or indeed they may even be moulded as part of the manufacturing process of the enclosure. As a further development, the incubator may include a hole for receiving an IV line in one of the end units or in the patient enclosure. This allows the IV line to enter the enclosure without allowing too much air to escape. Many holes of different sizes could be provided, for different purposes. In some cases, the hole for receiving an IV line includes a cover for blocking the hole when an IV line is not received in the hole. This prevents unnecessary leaks of the carefully controlled environment when the IV hole(s) are not in use.

The incubator may further be provided with means for reversibly mounting the incubator on a hospital bed or trolley, for example one or more of: straps; clips; and/or clamps. This allows the incubator to be placed securely on existing hospital equipment, for convenient monitoring.

Many incubation systems generate warm air, and deliver it directly to the patient enclosure. However, this risks inhomogeneities in the temperature distribution. It can be beneficial for the warmed air to be used to warm the walls of the patient enclosure prior to entering the first chamber. By forcing the air path to include portions which run through an air path bounded by at least part of an internal wall of the first chamber, the temperature distribution is improved, due to heating through the walls. Various solutions to the problem of how to efficiently heat the chamber in this way are presented herein.

In some cases the patient enclosure comprises: a first chamber for receiving a patient, the first chamber being defined by one or more walls and having a first end and a second end opposing the first end; and a second chamber defined by one or more walls, at least one wall of the second chamber being arranged adjacent to a wall of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap located at or adjacent to the first end of the first chamber; and one or more apertures located at or adjacent to the second end of the first chamber wherein the or each aperture fluidly connects the air gap to the interior of the first chamber; and wherein each aperture is located at or adjacent to the second end of the first chamber, so that an air flow path from the inlet to the interior of the first chamber traverses a portion of the air gap between the first and second ends of the first chamber. By forcing the air to follow a flow path between the two ends, the warmed air spends a significant amount of time next to the exterior walls of the first chamber, improving the warming effect. In the above description, the two ends broadly represent the maximum extent of the first chamber in opposite directions along an axis, i.e. along a particular direction in 3D space (for example length, width or height of the first chamber) along which the first chamber extends. Where the apertures or inlet are adjacent to the first or second end, this means that they are located substantially at the same location as that end. This does not mean that they must be located exactly at the furthest extent of the inner chamber at that location (i.e. exactly at the end), but that every one of the apertures is located close to the furthest extent, for example within 10% of the distance between the total length in that direction. This has the effect, for example, that the air flow path extends along substantially the entire extent in that direction for the same reasons. Where each aperture is described as being located at or adjacent the second end of the first chamber, this does not preclude other apertures being present for other reasons. For example, as set out above, there may be doors or IV holes, which can be used to create a hole into the inner chamber (e.g. for placing a patient inside, or for inserting an IV line). These holes are intended to be negligibly small (in the case of IV lines) or closable (in the case of both the door and some examples of IV lines) to leave substantially no hole during the normal operation of the incubator. The description of apertures above should therefore be interpreted as referring only to the apertures specifically connecting the air gap to the interior of the first chamber for the purposes of allowing air flow as described above.

Another example of a solution to the same problem is a kit of parts of the type described above wherein the patient enclosure comprises: a first chamber for receiving a patient, the first chamber being defined by one or more walls; and a second chamber defined by one or more walls, at least one of walls of the second chamber arranged adjacent to one of the one or more walls of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap; a plurality of apertures fluidly connecting the air gap to the interior of the first chamber including at least two different aperture sizes; and wherein the inlet and the aperture are spaced apart from one another so that an air flow path from the inlet to the interior of the first chamber includes traversing a portion of the air gap and wherein smaller apertures are located closer than larger apertures to the inlet. A system such as this has the advantage that warm air enters all along the surface, thus improving the distribution of warm air inside the patient enclosure. Arranging the apertures such that the smallest apertures are closest to the inlet and the largest are furthest away reduces the amount of warm air which enters the patient enclosure close to the inlet, and forces the air to spend more time traversing the exterior of the patient enclosure to achieve the warming effect set out above. In the event that there are more than two sizes of aperture, the general concept can be followed, meaning that the smallest apertures are the ones closest to the inlet, the next smallest are the next closest, and so on until the largest apertures are located the furthest from the inlet. That is, each aperture is larger than the apertures to one side of it (if any) and smaller than the apertures on the other side of it (if any). For the avoidance of doubt, there can be multiple apertures of the same size located approximately the same distance from the inlet. These examples can be seen to be very closely linked solutions, since in each case the largest apertures are the furthest from the inlet. In the first example, these apertures are the only apertures, so they are the largest by definition. In the second example, the apertures are arranged to become progressively larger the further they are from the inlet. In either case, the effect is to retain the air in the air gap for longer before it enters the interior of the first chamber.

The second chamber may at least partially enclose the first chamber. In some cases, the air gap at least partially surrounds the first chamber. This may allow for a larger air flow path.

In many examples, there is a plurality of apertures spaced around the one or more walls of the first chamber. In this case, the plurality of apertures helps to spread the warmth evenly throughout the first chamber.

In some cases the first and second chambers are flexible, collapsible, or are configured such that the air gap inflates when positive pressure is supplied to the inlet. This provides the advantages set out above in respect of a flexible, inflatable or collapsible patient enclosure, when both chambers have that property.

Optionally, the walls of the first chamber include upper and lower surfaces, two side walls and first and second end walls arranged in a generally cuboidal shape. This is a convenient shape for transporting and stacking, as well as for housing a patient.

There are many possible air flow paths in such a system. For example, the air flow path may include a portion of the air gap adjacent to the lower surface of the first chamber. This results in a first chamber which is easier to clean. Alternatively or additionally, the air flow path can include a portion of the air gap adjacent to the upper surface of the first chamber. This provides a desirable thermal gradient in the first chamber. In yet more examples, the air flow path may additionally or alternatively include a portion of the air gap adjacent to one or both of the side walls of the first chamber. Such an arrangement may be simpler to manufacture than other designs. In some cases the or at least one of the apertures is located in the first end wall and the inlet is located adjacent to the second end wall. This forces the warm air to traverse an entire outer surface of the first chamber before it enters the first chamber. This helps to warm the entire chamber through at least one of the walls, prior to entering, providing more even heating.

The or each of the plurality of apertures may be located in the lower surface of the inner enclosure. In other examples, the or each of the plurality of apertures may be located in the upper surface of the inner enclosure. As set out above, this provides a desirable thermal gradient in the first enclosure. In still more examples, the or each of the plurality of apertures is located in one or both of the side walls of the inner enclosure. In some cases, the incubator further comprises an outlet from the patient enclosure for allowing air to flow out from the interior of the patient enclosure. This can prevent a buildup of excess pressure in the patient enclosure. In some cases, the outlet is connected to a heater and fan for recirculating air leaving the first chamber through the outlet. By recirculating the air, much of the warmth can be retained, improving operational efficiency. A blend of fresh, cool air with recirculated air can be used to ensure a sufficient supply of oxygen. The inventors have found a wide range of mixtures to be suitable. An efficient mixture may use at least half recycled air, and even up to 95% recirculated. A mix of about 90% recirculated with about 10% fresh is particularly suitable. The patient enclosure may further include air circulation vents. These come in the form of perforations or other apertures in the patient enclosure. In the event that the air supply (e.g. a fan) fails, fresh (i.e. oxygenated, temperature- and humidity-controlled, etc.) air is no longer delivered to the interior of the patient enclosure. Therefore, one or more vents may be provided to connect the interior of the enclosure to the outside world, thereby allowing fresh air in, in the event of such a fan failure or other air supply issue. Put another way, these air circulation holes (i.e. the vents) are included in patient enclosure to allow for air to flow in and out passively. The air circulation holes mean that if all power is lost to the incubator then the holes act as a safety mechanism so that the patient always has access to oxygenated air in any type of scenario.

While any location on the exterior of the patient enclosure is suitable for vent placement, some locations are preferred. For example, where the enclosure is largely flexible with rigid portions, the vents can advantageously be provided in the rigid portions. This is because if the flexible portion collapses, the vents are more likely to remain open if they are in the rigid portion, but may become blocked by the collapsing flexible portion if they are located in the flexible portion. In some cases, the vents may be located in parts of the enclosure to which it is otherwise difficult to ensure air flow. For example, in the hypothetical example that it is found that a corner region of a cuboidal enclosure receives less air than other parts of the enclosure, yet air is desired in that region, then a vent may be placed in that corner region so that air flows through the region as it leaks out of the vent.

Any such air circulation vents should be sized and shaped so as to ensure that they do not disrupt existing air flow paths. For example, a large hole would cause a leak out of the enclosure and greatly reduce the ability of the incubator to provide a climate-controlled environment. Even where the vents are part of the flow paths, as set out above, too large a hole can reduce the temperature to an unacceptable degree. Conversely, if the vent is too small, the beneficial effects may not be provided sufficiently to ensure patient safety. Multiple vents may be used in some cases, to ensure that the correct balance is struck. Depending on the size and shape of the enclosure, a variety of vent sizes and locations may be beneficially chosen to achieve the desired balance. It is within the skilled person's skills to determine a suitable vent distribution, sizing and shape for a given design, without undue experimentation.

Another manner in which the air flow paths may be preserved is to fit the vents with one-way flow elements (e.g. valves). These would be configured to allow air flow into the enclosure, but not out. Since there is air flow into the interior of the enclosure in normal operation, the enclosure operates at a slight positive pressure. This means that such oneway elements on the vents would be held shut, and no air would flow out of them. In the event of a fan failure, no positive pressure condition exists and the valves would open, thereby fulfilling their safety function. In some designs which use this idea, only some of the vents may be fit with one-way flow elements. In other such designs all of the vents may be provided with one-way air flow elements.

Also disclosed herein is a method of using a modular incubator, wherein the modular incubator comprises: a first end unit; and a patient enclosure having a first portion configured for attaching to the first end unit and a door for accessing the interior of the enclosure, wherein the enclosure is configured to extend away from first end unit, and wherein the first end unit is configured to provide support to the patient enclosure; wherein at least a portion of the patient enclosure is reversibly detachable for sterilisation or disposal and wherein the method includes: (a) assembling the modular incubator by reversibly attaching the reversibly detachable portion of the patient enclosure to the modular incubator; (b) using the patient enclosure to provide a controlled climate for a patient; and (c) detaching and disposing of or sterilising the detachable portion of the patient enclosure. In some cases, there may be two end units, the second end unit for example having some or all of the functionality of the first unit. For example, the functionality of the first end unit as described below may be split between the first and second end units, or it may be duplicated, or some combination of these. By providing a part of the patient enclosure as being reversibly detachable for sterilisation or disposal, the burden on medical staff to ensure that the enclosure is fit for purpose is greatly reduced, and the risk of infection from unclean surroundings is reduced. When it is noticed that the enclosure is no longer clean enough to provide adequate care, it, or the removable parts of it, can be removed and replaced with a sterile part, while the removed portion can be cleaned or disposed of. It is a significantly reduced burden on healthcare to retain a store of removable enclosure parts than to provide suitable cleaning facilities, or entire replacement incubators. In addition, typical cleaning and microbial testing procedures for incubators may take between 45 minutes and 2 hours, for example. The incubator described herein allows for a turnaround time of mere seconds. The actual task of cleaning could, for example be outsourced to an offsite facility. Reversibly detachable as used herein means that the portions in question may be removed from the rest of the assembly without damaging it. Moreover, such portions, or broadly equivalent replacement portions, can be reattached in the same manner as the original portion was attached, again without causing damage. As used herein, the term "configured to extend away from" should be construed to mean that when the patient enclosure is attached to the first unit, the assembled device has an extent that is larger in at least one direction than that of the end unit alone. In other words, while the patient enclosure may be configured so that, during the attachment and assembly process, it expands outwards to form a full-sized enclosure, other designs in which the enclosure is a wholly or partially rigid assembly for attaching to the end unit are also contemplated.

As used herein, "disposable" may mean that the patient enclosure may be lightweight, for example, or made from less durable materials than other incubators, or from relatively thin or soft plastics, for example. Enclosures of this type are only required to last for a week or so prior to replacement, rather than potentially years.

Optionally, the reversibly detachable portion may be an inner liner of the patient enclosure. This allows more of the enclosure to be maintained, and less discarded or sterilised, thereby reducing the environmental impact of replacing the removable portion. Additionally, the incubator can be supplied as a complete unit, which requires simply the liner to be fitted. The inner liner may cover the entirety of the internal surfaces, or it may cover only some of the internal surfaces in some cases. This can speed up the preparation of the incubator. In addition, the replaceable nature of the patient enclosure means that a single end unit can be used with a variety of enclosures for its lifetime, so for example a selection of enclosures of different sizes can be used to accommodate different aged patients. Additionally or alternatively, the entire patient enclosure is reversibly detachable for sterilisation or disposal. In other words, the patient enclosure may be a standalone unit in the sense that the entire enclosure may be separable from the functional portions of the incubator, so that the entire patient enclosure can be supplied separately and can be replaced as a whole unit. For example, the first and/or second portions of the patient enclosure may not have any type of removable insert but instead the enclosure may be a standalone flexible structure that is attached to the end units using a fastening method such as clips, zippers or hooks. This allows medical staff to quickly and easily replace an entire section of the incubator. When both the liner and the entire enclosure are removable, the liner can be replaced regularly without interrupting treatment (i.e. with minimal interference), and the entire enclosure can be replaced between patients, thereby maximising the benefits of having each portion alone being removable.

In the case of the removable portion being an inner liner, it may be reversibly attached to the interior surfaces of the enclosure by way of a hook and look fastening system, releasable adhesive, zips, buttons, clips, poppers, etc., or any other suitable means.

The patient enclosure may be reversibly attachable to the first and/or second end units by virtue of cooperating attachment means on the first portion and the first end unit and/or on the second portion and the second end unit. Examples of suitable attachment means are zips, buttons, poppers, toggles and eyeholes, or various forms of clips, examples of which are described in detail below

The first and/or second portion of the patient enclosure may include a rigid insert. Rigid inserts can help certain portions of the enclosure to retain their shape. Preferably, the insert or inserts comprise planar portions, so that the collapsible, inflatable and/or flexible variants of the design are able to reduce to ta relatively small volume. This can help the patient enclosure to be stored efficiently when not in use, but to still provide a support structure to the enclosure.

The or each rigid insert is provided in a pocket in the first and/or second portion, for example the rigid insert(s) may be removably inserted in a pocket in the first and/or second portion of the enclosure, e.g. held in place by friction, or by a removable closure on the pocket, for example a hook and look fastening system, releasable adhesive, zips, buttons, etc., or the insert may be permanently mounted in the pocked, for example welded in place, or fixed with permanent adhesive. The method optionally includes inserting the or each rigid insert into the or each pocket during step (a). In some examples, the rigid insert(s) may be permanently affixed to the enclosure itself, without the need for a pocket at all. For example, the rigid portions may be permanently mechanically fixed to the enclosure by screws, rivets, staples and the like. In other examples they may be either formed integrally with the enclosure, or they may be bonded to the enclosure by means of adhesives, welding, or the like. In these latter examples, the rigid material will be made of a compatible material, e.g. one which can be bonded or welded to the material of the enclosure. This may mean that the rigid portion is made from the same material as the enclosure. In other cases, e.g. where the enclosure must be flexible but the inserts must be rigid, it may not be possible to make both from the same material, but a pairing can be chosen by consulting a known list of compatible materials. This rigid portion can help parts of the enclosure to retain their shape. This allows for the reduction in use of material overall for the patient enclosure whilst keeping the rigidity of using an insert.

In some examples, the attachment means on the patient enclosure are provided on the rigid insert. This allows the attachment means to make use of rigid components, while not requiring the entire enclosure to be rigid.

The cooperating attachment means may comprise one or more of: buttons and holes; toggles; and/or clips. Many of the attachment means suitable for use in this situation are described in detail below.

In other examples, the cooperating attachment means comprise a rigid lip on one or both of the end units and a flexible region of the patient enclosure at one or both of the first and second portions for stretching over the or each lip and wherein step (a) includes stretching the or each flexible region over the or each lip. Thus by simply stretching the first and/or second portions over the lip, a connection can be made, without any complex moving parts. To assist with the attachment, the or each flexible region may be formed from an elastic material. One or more of: air supply; air heaters; power supply; water supply; temperature probes; attachments for weigh scales; X-ray tables; and/or air filters may optionally be housed in the first and/or second end unit. This allows the active parts of the incubator system (e.g. for supplying and maintaining the desired environmental conditions) to be kept separate from the patient enclosure. Since some or all of the enclosure is removable, this can help to ensure that the more delicate and expensive components are kept out of harm's way.

The patient enclosure may be collapsible, such that it is configurable in an expanded configuration, and a collapsed configuration, wherein the expanded configuration occupies more space than the collapsed configuration, and step (a) includes expanding the patient enclosure from its collapsed configuration to its expanded configuration. This allows the disposable portions of the incubator system to be supplied and stored in the collapsed configuration, to save space, and promote efficient transport, without diminishing the space available for patient care. In the expanded configuration, the first and second portions may face one another. This provides a convenient shape for the patient enclosure. Moreover, step (c) may include collapsing the patient enclosure from its expanded configuration to its collapsed configuration. This provides a compact configuration for transporting, whether for sterilisation or disposal.

The patient enclosure may be flexible, and/or inflatable. This vastly simplifies the transition between expanded and collapsed configurations. Optionally, the patient enclosure may comprise a double walled construction, for example. Where the patient enclosure is inflatable, step (b) may be performed with the patient enclosure inflated. This is a stable arrangement for maintaining the patient in comfort.

The patient enclosure may be flexible, and/or inflatable. This vastly simplifies the transition between expanded and collapsed configurations. Optionally, the patient enclosure may comprise a double walled construction, for example.

The modular incubator optionally includes a humidification means. It is often desirable to control the humidity of the air inside an incubator, in order to provide the best environment for the patient. An example of humidification means is a container of sterile water. This container may be placed (or mounted) in the patient enclosure to provide a steady amount of humidity. Such a container of sterile water may be removable from the patient enclosure, for example, so that it is only present in cases where increased humidity is desirable. The method may, for example, include a step of placing the container of sterile water in the patient enclosure prior to or during step (b). Indeed, containers of this type can be supplied separately from the rest of the incubator, and mounted in the enclosure only when needed. This reduces unnecessary waste by only providing humidity means when required. The container of sterile water may include a removable cap for controlling whether humidification of the patient enclosure occurs. The method may additionally include removing the cap prior to or during step (b). This means that the container can be left in place until such time as humidity is deemed desirable, without prematurely humidifying the enclosure.

Advantageously, the container of sterile water may include a permeable cover for controlling the amount of humidification supplied to the patient enclosure. The cover may hinder the release of moisture to provide humidity at a controlled level. For example, the cover may be provided underneath the removable cap (where present), and the cover may be either removable or permanently attached. The cover itself may be made of a porous or perforated material, which acts to change the surface area of water exposed to the environment relative to a simple open container. A porous material may increase the surface area by adsorption of the moisture on the material, while a perforated material may reduce the surface area by blocking the evaporation path of the water.

The exact change in release rate can be tailored to meet healthcare guidelines for specific situations. For example, in the case where the water container is removable from the enclosure, the containers for fitting into the enclosure can be supplied in a graded series which provide progressively more humidity to the enclosure. In the event that a particular humidity level is required, the appropriate container can be selected and fitted into the enclosure. In another example, the cover may be removable, and a series of covers may be supplied with the containers, each corresponding to a different humidity level. The method optionally includes selecting a cover according to the desired level of humidity and applying the selected cover to the container of sterile water prior to or during step (b). For example, each of the covers may have a different permeability, and may correspond to a different level of humidity in the patient enclosure. When a particular level of humidity is required, the appropriate cover can be selected and fit to the container which is itself mounted in the enclosure. The covers can even be reusable, to further reduce waste.

Another example of a suitable humidification means comprises a water supply connected to a controllable humidifier. This may be located inside the enclosure, or coupled to an air supply to the interior of the enclosure to deliver already humid air to the enclosure. The exact level of humidity can be closely controlled in this manner. The method optionally includes controlling the humidifier to provide a desired level of humidity prior to or during step (b).

The above examples may each be provided with an on board water supply. The water supply may be refillable, but in any case, the capacity of the on board water supply may be configured to match that of the expected duration of the patient enclosure before the enclosure (or a portion thereof) is replaced. For example the water supply may be arranged to last for a week. In each case, the rate of release of moisture may not be constant, but may change over time. For example, it is common for neonatal babies to require a higher level of humidity initially, which decreases with time as the baby ages. When the design is the container version, rather than requiring staff to regularly replace the cover, this could be achieved using a tapered container, for example, in which the surface area of the water in the container changes as the water level drops, thereby changing the release rate of humidity into the air. In the case of the controllable humidifier, a programming function could be used to ensure that the rate of humidification is appropriate, possibly in conjunction with the use of feedback, set points, and sensors to detect the humidity and control the humidifier. The amount of humidity is usually determined by a medical professional, but may be up to 95%. A useful range of humidity to provide in the enclosure could be between 30% and 95%, for example by providing a series of covers as set out above, graduated in 5% increments.

The provision of humidification means for the patient enclosure may be applied to any incubator design, and not just those specifically discussed herein. For example, there may be provided a humidifier for use in an incubator, comprising a water source and a means for vaporising the water source. Optionally, the means for vaporising may be electrical, or a wick, sponge or exposed surface area of the water, for example any of those means discussed above. Optionally, the various means for controlling the timing and quantity of humidity described above are applied to the stand alone humidifier.

In some examples, the incubator functionality is housed in the first end unit and the patent enclosure is reversibly detachable from the first end unit, and the modular incubator includes couplings for connecting the patient enclosure to the first end unit and the incubator functionality is configured to supply one or more of: electrical power; heated air; and/or water to the patient enclosure via the couplings when the first portion is detached from the first end unit. In this context, incubator functionality means the active components of the incubator, such as those for generating and/or supplying warm air, air pressure, water, power, etc. to the interior of the patient enclosure. Arranging the modular incubator in this manner provides resilience against damage from medical scanning machines, while they are in use. For example, MRI machines use strong magnetic fields, which can damage electrical equipment, introduce interference into electrical monitoring systems, and strongly attract ferromagnetic materials, which can cause damage to the structure of devices if they are suddenly pulled towards the MRI scanner (possibly impacting the scanner at speed). Similarly, CT scanners use large doses of X-rays, which can damage electronics and affect electronic read outs. In such cases, the method may include detaching the patient enclosure from the first end unit but retaining the couplings during step (b). For example, the patient enclosure may be placed inside a medical scanner while the patient enclosure is detached from the first end unit but retains the couplings during step (b).

In any of the above examples, the door may generally rectangular and is hinged along one edge and also hinged along a line across the generally rectangular shape of the door. This allows the door to be opened in two parts, for example, the hinge along one edge may be used to create a large opening to allow a patient to be placed into the enclosure, for example during step (a). During the patient's time in the incubator, it is important that the warm environment is not disturbed. Therefore, when routine checks are required, the hinge which operates across the face of the door may be used, which makes a smaller gap, and thus reduces unnecessary air loss, while still providing a sufficient gap for the hands of medical staff to carry out any tasks necessary, for example during step (b).

In some examples, the first and/or second end unit comprises a fan and/or a heater removably mounted on a break out board. Fans and heaters are critical components in incubators, and if they fail the incubator quickly becomes ineffective. By mounting the fan and/or heater on a break out board (for example both on the same board, or each on its own board), any fault can be quickly assessed and corrected. In simple cases, the solution may be to repair the problem in situ. In more complex cases, the whole board can be switched out for a new one. The method may for example include removing the break out board and replacing the fan and/or the heater in the event that the fan and/or heater has malfunctioned during any of the operational steps of the method. Similar faults in known incubators would require at best a lengthy dismantling and repair process, but more commonly replacement of the entire incubator or returning the entire incubator to the manufacturer for repair. Optionally, the modular incubator further comprises an IV line holder inside the patient enclosure. Typical solutions for holding IV lines need to be added to incubator units after their manufacture, presenting a risk that the attachment is not strong enough. Equally, loose attachments may cause the holder to fall off, and get lost, increasing upkeep expenses. By providing one or more IV lines as part of the incubator, for example moulded as part of the patient enclosure or the end units, a relatively cost effective means is provided for securely mounting IV lines to the incubator. In addition, IV line holders should be cleaned and sterilised between uses. In other incubator designs, this can be a complicated process. In the present apparatus, the IV lines can be removed when the patient enclosure (or part thereof) is detached, and disposed of or sterilised as part of the process, while a new enclosure is fitted. This can greatly speed up the turnaround time of an incubator between patients. The IV lines may be supplied clipped to the patient enclosure, or indeed they may even be moulded as part of the manufacturing process of the enclosure.

As a further development, the incubator may include a hole for receiving an IV line in one of the end units or in the patient enclosure. This allows the IV line to enter the enclosure without allowing too much air to escape. Many holes of different sizes could be provided, for different purposes. In some cases, the hole for receiving an IV line includes a cover for blocking the hole when an IV line is not received in the hole. This prevents unnecessary leaks of the carefully controlled environment when the IV hole(s) are not in use.

The method may comprise mounting an IV line into the IV line holder during step (a) or step (b) and optionally may comprise further includes threading an IV line through the hole during step (a) or step (b). Additionally, or alternatively the method may include removing an IV line from the IV line holder during or after step (b), or during or after step (c), optionally further comprising removing the IV line from the hole during or after step (b), or during or after step (c). In any case, the method may include covering the hole during step (b) while the IV line is not in the hole.

The modular incubator may further be provided with means for reversibly mounting the modular incubator on a hospital bed or trolley, for example one or more of: straps; clips; and/or clamps. This allows the incubator to be placed securely on existing hospital equipment, for convenient monitoring. The method may optionally include mounting the modular incubator to a hospital bed or trolley prior to step (b). Additionally, the method may further comprise detaching the modular incubator from the hospital bed or trolley prior during or after step (b). Many incubation systems generate warm air, and deliver it directly to the patient enclosure. However, this risks inhomogeneities in the temperature distribution. It can be beneficial for the warmed air to be used to warm the walls of the patient enclosure prior to entering the first chamber. By forcing the air path to include portions which run through an air path bounded by at least part of an internal wall of the first chamber, the temperature distribution is improved, due to heating through the walls. Various solutions to the problem of how to efficiently heat the chamber in this way are presented herein.

In some cases the patient enclosure comprises: a first chamber for receiving a patient, the first chamber being defined by one or more walls and having a first end and a second end opposing the first end; and a second chamber defined by one or more walls, at least one wall of the second chamber being arranged adjacent to a wall of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap located at or adjacent to the first end of the first chamber; and one or more apertures located at or adjacent to the second end of the first chamber wherein the or each aperture fluidly connects the air gap to the interior of the first chamber; and wherein each aperture is located at or adjacent to the second end of the first chamber, so that an air flow path from the inlet to the interior of the first chamber traverses a portion of the air gap between the first and second ends of the first chamber, and wherein the method further includes supplying air to the inlet during step (b). . By forcing the air to follow a flow path between the two ends, the warmed air spends a significant amount of time next to the exterior walls of the first chamber, improving the warming effect. In the above description, the two ends broadly represent the maximum extent of the first chamber in opposite directions along an axis, i.e. along a particular direction in 3D space (for example length, width or height of the first chamber) along which the first chamber extends. Where the apertures or inlet are adjacent to the first or second end, this means that they are located substantially at the same location as that end. This does not mean that they must be located exactly at the furthest extent of the inner chamber at that location (i.e. exactly at the end), but that every one of the apertures is located close to the furthest extent, for example within 10% of the distance between the total length in that direction. This has the effect, for example, that the air flow path extends along substantially the entire extent in that direction for the same reasons. Where each aperture is described as being located at or adjacent the second end of the first chamber, this does not preclude other apertures being present for other reasons. For example, as set out above, there may be doors or IV holes, which can be used to create a hole into the inner chamber (e.g. for placing a patient inside, or for inserting an IV line). These holes are intended to be negligibly small (in the case of IV lines) or closable (in the case of both the door and some examples of IV lines) to leave substantially no hole during the normal operation of the incubator. The description of apertures above should therefore be interpreted as referring only to the apertures specifically connecting the air gap to the interior of the first chamber for the purposes of allowing air flow as described above. Another example of a solution to the same problem is a method of using a modular incubator in which the patient enclosure comprises: a first chamber for receiving a patient, the first chamber being defined by one or more walls; and a second chamber defined by one or more walls, at least one of walls of the second chamber arranged adjacent to one of the one or more walls of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap; a plurality of apertures fluidly connecting the air gap to the interior of the first chamber including at least two different aperture sizes; and wherein the inlet and the aperture are spaced apart from one another so that an air flow path from the inlet to the interior of the first chamber includes traversing a portion of the air gap and wherein smaller apertures are located closer than larger apertures to the inlet and wherein the method further includes supplying air to the inlet during step (b). A system such as this has the advantage that warm air enters all along the surface, thus improving the distribution of warm air inside the patient enclosure. Arranging the apertures such that the smallest apertures are closest to the inlet and the largest are furthest away reduces the amount of warm air which enters the patient enclosure close to the inlet, and forces the air to spend more time traversing the exterior of the patient enclosure to achieve the warming effect set out above. In the event that there are more than two sizes of aperture, the general concept can be followed, meaning that the smallest apertures are the ones closest to the inlet, the next smallest are the next closest, and so on until the largest apertures are located the furthest from the inlet. That is, each aperture is larger than the apertures to one side of it (if any) and smaller than the apertures on the other side of it (if any). For the avoidance of doubt, there can be multiple apertures of the same size located approximately the same distance from the inlet.

These examples can be seen to be very closely linked solutions, since in each case the largest apertures are the furthest from the inlet. In the first example, these apertures are the only apertures, so they are the largest by definition. In the second example, the apertures are arranged to become progressively larger the further they are from the inlet. In either case, the effect is to retain the air in the air gap for longer before it enters the interior of the first chamber.

The second chamber may at least partially enclose the first chamber. In some cases, the air gap at least partially surrounds the first chamber. This may allow for a larger air flow path. In many examples, there is a plurality of apertures spaced around the one or more walls of the first chamber. In this case, the plurality of apertures helps to spread the warmth evenly throughout the first chamber. In some cases the first and second chambers are flexible, collapsible, or are configured such that the air gap inflates when positive pressure is supplied to the inlet. This provides the advantages set out above in respect of a flexible, inflatable or collapsible patient enclosure, when both chambers have that property. Optionally, the walls of the first chamber include upper and lower surfaces, two side walls and first and second end walls arranged in a generally cuboidal shape. This is a convenient shape for transporting and stacking, as well as for housing a patient.

There are many possible air flow paths in such a system. For example, the air flow path may include a portion of the air gap adjacent to the lower surface of the first chamber. This results in a first chamber which is easier to clean. Alternatively or additionally, the air flow path can include a portion of the air gap adjacent to the upper surface of the first chamber. This provides a desirable thermal gradient in the first chamber. In yet more examples, the air flow path may additionally or alternatively include a portion of the air gap adjacent to one or both of the side walls of the first chamber. Such an arrangement may be simpler to manufacture than other designs.

The or each of the plurality of apertures may be located in the lower surface of the inner enclosure. In other examples, the or each of the plurality of apertures may be located in the upper surface of the inner enclosure. As set out above, this provides a desirable thermal gradient in the first enclosure. In still more examples, the or each of the plurality of apertures is located in one or both of the side walls of the first chamber.

In some cases, the incubator further comprises an outlet from the patient enclosure for allowing air to flow out from the interior of the patient enclosure. This can prevent a buildup of excess pressure in the patient enclosure. In some cases, the outlet is connected to a heater and fan for recirculating air leaving the first chamber through the outlet. By recirculating the air, much of the warmth can be retained, improving operational efficiency. A blend of fresh, cool air with recirculated air can be used to ensure a sufficient supply of oxygen. The inventors have found a wide range of mixtures to be suitable. An efficient mixture may use at least half recycled air, and even up to 95% recirculated. A mix of about 90% recirculated with about 10% fresh is particularly suitable. The method may therefore also include recirculating air leaving the patient enclosure through the outlet.

Many incubation systems generate warm air, and deliver it directly to the patient enclosure. However, this risks inhomogeneities in the temperature distribution. It can be beneficial for the warmed air to be used to warm the walls of the patient enclosure prior to entering the first chamber. By forcing the air path to include portions which run through an air path bounded by at least part of an internal wall of the first chamber, the temperature distribution is improved, due to heating through the walls. Various solutions to the problem of how to efficiently heat the chamber in this way are presented herein.

Following this idea there is also described herein a housing for an incubator, comprising: a first chamber for receiving a patient, the first chamber being defined by one or more walls and having a first end and a second end opposing the first end; and a second chamber defined by one or more walls, at least one wall of the second chamber being arranged adjacent to a wall of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap located at or adjacent to the first end of the first chamber; and one or more apertures located at or adjacent to the second end of the first chamber wherein the or each aperture fluidly connects the air gap to the interior of the first chamber; and wherein each aperture is located at or adjacent to the second end of the first chamber, so that an air flow path from the inlet to the interior of the first chamber traverses a portion of the air gap between the first and second ends of the first chamber. By forcing the air to follow a flow path between the two ends, the warmed air spends a significant amount of time next to the exterior walls of the first chamber, improving the warming effect. In the above description, the two ends broadly represent the maximum extent of the first chamber in opposite directions along an axis, i.e. along a particular direction in 3D space (for example length, width or height of the first chamber) along which the first chamber extends. Where the apertures or inlet are adjacent to the first or second end, this means that they are located substantially at the same location as that end. This does not mean that they must be located exactly at the furthest extent of the inner chamber at that location (i.e. exactly at the end), but that every one of the apertures is located close to the furthest extent, for example within 10% of the distance between the total length in that direction. This has the effect, for example, that the air flow path extends along substantially the entire extent in that direction for the same reasons. Where each aperture is described as being located at or adjacent the second end of the first chamber, this does not preclude other apertures being present for other reasons. For example, as set out above, there may be doors or IV holes, which can be used to create a hole into the inner chamber (e.g. for placing a patient inside, or for inserting an IV line). These holes are intended to be negligibly small (in the case of IV lines) or closable (in the case of both the door and some examples of IV lines) to leave substantially no hole during the normal operation of the incubator. The description of apertures above should therefore be interpreted as referring only to the apertures specifically connecting the air gap to the interior of the first chamber for the purposes of allowing air flow as described above.

Another example of a solution to this same problem is a housing for an incubator, comprising: a first chamber for receiving a patient, the first chamber being defined by one or more walls; and a second chamber defined by one or more walls, at least one of walls of the second chamber arranged adjacent to one of the one or more walls of the first chamber and defining an air gap therebetween; an inlet for receiving warmed air into the air gap; a plurality of apertures fluidly connecting the air gap to the interior of the first chamber including at least two different aperture sizes; and wherein the inlet and the aperture are spaced apart from one another so that an air flow path from the inlet to the interior of the first chamber includes traversing a portion of the air gap and wherein smaller apertures are located closer than larger apertures to the inlet. A system such as this has the advantage that warm air enters all along the surface, thus improving the distribution of warm air inside the patient enclosure. Arranging the apertures such that the smallest apertures are closest to the inlet and the largest are furthest away reduces the amount of warm air which enters the patient enclosure close to the inlet, and forces the air to spend more time traversing the exterior of the patient enclosure to achieve the warming effect set out above. In the event that there are more than two sizes of aperture, the general concept can be followed, meaning that the smallest apertures are the ones closest to the inlet, the next smallest are the next closest, and so on until the largest apertures are located the furthest from the inlet. That is, each aperture is larger than the apertures to one side of it (if any) and smaller than the apertures on the other side of it (if any). For the avoidance of doubt, there can be multiple apertures of the same size located approximately the same distance from the inlet. These examples can be seen to be very closely linked solutions, since in each case the largest apertures are the furthest from the inlet. In the first example, these apertures are the only apertures, so they are the largest by definition. In the second example, the apertures are arranged to become progressively larger the further they are from the inlet. In either case, the effect is to retain the air in the air gap for longer before it enters the interior of the first chamber. The second chamber may at least partially enclose the first chamber. In some cases, the air gap at least partially surrounds the first chamber. This may allow for a larger air flow path. In many examples, there is a plurality of apertures spaced around the one or more walls of the first chamber. In this case, the plurality of apertures helps to spread the warmth evenly throughout the first chamber.

In some cases the first and second chambers are flexible, collapsible, or are configured such that the air gap inflates when positive pressure is supplied to the inlet. This provides the advantages set out above in respect of a flexible, inflatable or collapsible patient enclosure, when both chambers have that property.

Optionally, the walls of the first chamber include upper and lower surfaces, two side walls and first and second end walls arranged in a generally cuboidal shape. This is a convenient shape for transporting and stacking, as well as for housing a patient.

There are many possible air flow paths in such a system. For example, the air flow path may include a portion of the air gap adjacent to the lower surface of the first chamber. This results in a first chamber which is easier to clean. Alternatively or additionally, the air flow path can include a portion of the air gap adjacent to the upper surface of the first chamber. This provides a desirable thermal gradient in the first chamber. In yet more examples, the air flow path may additionally or alternatively include a portion of the air gap adjacent to one or both of the side walls of the first chamber. Such an arrangement may be simpler to manufacture than other designs.

In some cases the or at least one of the apertures is located in the first end wall and the inlet is located adjacent to the second end wall. This forces the warm air to traverse an entire outer surface of the first chamber before it enters the first chamber. This helps to warm the entire chamber through at least one of the walls, prior to entering, providing more even heating.

The or each of the plurality of apertures may be located in the lower surface of the inner enclosure. In other examples, the or each of the plurality of apertures may be located in the upper surface of the inner enclosure. As set out above, this provides a desirable thermal gradient in the first enclosure. In still more examples, the or each of the plurality of apertures is located in one or both of the side walls of the first chamber. In any of the above examples, the housing may include a door for accessing the interior of the enclosure. The door may generally rectangular and is hinged along one edge and also hinged along a line across the generally rectangular shape of the door. This allows the door to be opened in two parts, for example, the hinge along one edge may be used to create a large opening to allow a patient to be placed into the enclosure. During the patient's time in the incubator, it is important that the warm environment is not disturbed. Therefore, when routine checks are required, the hinge which operates across the face of the door may be used, which makes a smaller gap, and thus reduces unnecessary air loss, while still providing a sufficient gap for the hands of medical staff to carry out any tasks necessary.

In some cases, the housing further comprises an outlet from the patient enclosure for allowing air to flow out from the interior of the patient enclosure. This can prevent a build-up of excess pressure in the patient enclosure. In some cases, the outlet is connectable to a heater and fan for recirculating air leaving the first chamber through the outlet. By recirculating the air, much of the warmth can be retained, improving operational efficiency. A blend of fresh, cool air with recirculated air can be used to ensure a sufficient supply of oxygen. The inventors have found a wide range of mixtures to be suitable. An efficient mixture may use at least half recycled air, and even up to 95% recirculated. A mix of about 90% recirculated with about 10% fresh is particularly suitable.

The patient enclosure may further include air circulation vents. These come in the form of perforations or other apertures in the patient enclosure. In the event that the air supply (e.g. a fan) fails, fresh (i.e. oxygenated, temperature- and humidity-controlled, etc.) air is no longer delivered to the interior of the patient enclosure. Therefore, one or more vents may be provided to connect the interior of the enclosure to the outside world, thereby allowing fresh air in, in the event of such a fan failure or other air supply issue. Put another way, these air circulation holes (i.e. the vents) are included in patient enclosure to allow for air to flow in and out passively. The air circulation holes mean that if all power is lost to the incubator then the holes act as a safety mechanism so that the patient always has access to oxygenated air in any type of scenario.

While any location on the exterior of the patient enclosure is suitable for vent placement, some locations are preferred. For example, where the enclosure is largely flexible with rigid portions, the vents can advantageously be provided in the rigid portions. This is because if the flexible portion collapses, the vents are more likely to remain open if they are in the rigid portion, but may become blocked by the collapsing flexible portion if they are located in the flexible portion.

In some cases, the vents may be located in parts of the enclosure to which it is otherwise difficult to ensure air flow. For example, in the hypothetical example that it is found that a corner region of a cuboidal enclosure receives less air than other parts of the enclosure, yet air is desired in that region, then a vent may be placed in that corner region so that air flows through the region as it leaks out of the vent. Any such air circulation vents should be sized and shaped so as to ensure that they do not disrupt existing air flow paths. For example, a large hole would cause a leak out of the enclosure and greatly reduce the ability of the incubator to provide a climate-controlled environment. Even where the vents are part of the flow paths, as set out above, too large a hole can reduce the temperature to an unacceptable degree. Conversely, if the vent is too small, the beneficial effects may not be provided sufficiently to ensure patient safety. Multiple vents may be used in some cases, to ensure that the correct balance is struck. Depending on the size and shape of the enclosure, a variety of vent sizes and locations may be beneficially chosen to achieve the desired balance. It is within the skilled person's skills to determine a suitable vent distribution, sizing and shape for a given design, without undue experimentation.

Another manner in which the air flow paths may be preserved is to fit the vents with one-way flow elements (e.g. valves). These would be configured to allow air flow into the enclosure, but not out. Since there is air flow into the interior of the enclosure in normal operation, the enclosure operates at a slight positive pressure. This means that such oneway elements on the vents would be held shut, and no air would flow out of them. In the event of a fan failure, no positive pressure condition exists and the valves would open, thereby fulfilling their safety function. In some designs which use this idea, only some of the vents may be fit with one-way flow elements. In other such designs all of the vents may be provided with one-way air flow elements.

The housing optionally includes a humidification means. It is often desirable to control the humidity of the air inside an incubator, in order to provide the best environment for the patient. An example of humidification means is a container of sterile water. This container may be placed (or mounted) in the patient enclosure to provide a steady amount of humidity. Such a container of sterile water may be removable from the patient enclosure, for example, so that it is only present in cases where increased humidity is desirable. Indeed, containers of this type can be supplied separately from the rest of the incubator, and mounted in the enclosure only when needed. This reduces unnecessary waste by only providing humidity means when required. The container of sterile water may include a removable cap for controlling whether humidification of the patient enclosure occurs. This means that the container can be left in place until such time as humidity is deemed desirable, without prematurely humidifying the enclosure.

Advantageously, the container of sterile water may include a permeable cover for controlling the amount of humidification supplied to the patient enclosure. The cover may hinder the release of moisture to provide humidity at a controlled level. For example, the cover may be provided underneath the removable cap (where present), and the cover may be either removable or permanently attached. The cover itself may be made of a porous or perforated material, which acts to change the surface area of water exposed to the environment relative to a simple open container. A porous material may increase the surface area by adsorption of the moisture on the material, while a perforated material may reduce the surface area by blocking the evaporation path of the water.

The exact change in release rate can be tailored to meet healthcare guidelines for specific situations. For example, in the case where the water container is removable from the enclosure, the containers for fitting into the enclosure can be supplied in a graded series which provide progressively more humidity to the enclosure. In the event that a particular humidity level is required, the appropriate container can be selected and fitted into the enclosure. In another example, the cover may be removable, and a series of covers may be supplied with the containers, each corresponding to a different humidity level. For example, each of the covers may have a different permeability, and may correspond to a different level of humidity in the patient enclosure. When a particular level of humidity is required, the appropriate cover can be selected and fit to the container which is itself mounted in the enclosure. The covers can even be reusable, to further reduce waste.

Another example of a suitable humidification means comprises a water supply connected to a controllable humidifier. The exact level of humidity can be closely controlled in this manner.

The above examples may each be provided with an on board water supply. The water supply may be refillable, but in any case, the capacity of the on board water supply may be configured to match that of the expected duration of the patient enclosure before the enclosure (or a portion thereof) is replaced. For example the water supply may be arranged to last for a week. In each case, the rate of release of moisture may not be constant, but may change over time. For example, it is common for neonatal babies to require a higher level of humidity initially, which should decrease with time. When the design is the container version, rather than requiring staff to regularly replace the cover, this could be achieved using a tapered container, for example, in which the surface area of the water in the container changes as the water level drops, thereby changing the release rate of humidity into the air. In the case of the controllable humidifier, a programming function could be used to ensure that the rate of humidification is appropriate, possibly in conjunction with the use of feedback, set points, and sensors to detect the humidity and control the humidifier. Optionally, the system further comprises an IV line holder inside the patient enclosure. Typical solutions for holding IV lines need to be added to incubator units after their manufacture, presenting a risk that the attachment is not strong enough. Equally, loose attachments may cause the holder to fall off, and get lost, increasing upkeep expenses. By providing one or more IV lines as part of the incubator, for example moulded as part of the patient enclosure or the end units, a relatively cost effective means is provided for securely mounting IV lines to the incubator.

As a further development, the incubator may include a hole for receiving an IV line in one of the end units or in the patient enclosure. This allows the IV line to enter the enclosure without allowing too much air to escape. Many holes of different sizes could be provided, for different purposes. In some cases, the hole for receiving an IV line includes a cover for blocking the hole when an IV line is not received in the hole. This prevents unnecessary leaks of the carefully controlled environment when the IV hole(s) are not in use. The incubator may further be provided with means for reversibly mounting the incubator on a hospital bed or trolley, for example one or more of: straps; clips; and/or clamps. This allows the incubator to be placed securely on existing hospital equipment, for convenient monitoring. As used above, air does not necessarily mean air simply drawn from the surroundings, although it can mean this. Various processing steps may be included prior to supplying the air to the patient enclosure, for example filtration, humidification, removal of unwanted parts (pollutants, excess carbon dioxide, poisonous or toxic components, etc.) or addition of beneficial parts, such as medication, additional oxygen, water vapour, etc. The main constraint is that the gas supplied must be breathable, safe and able to be heated to the desired temperature.

Aspects and embodiments of the invention will now be described with reference to the Figures, in which:

Figures 1A and 1 B show examples of the reversible detachment of a portion of a patient enclosure;

Figures 2A to 2C show examples of rigid inserts for the patient enclosure;

Figures 3A to 3D show examples of cooperating attachment means;

Figures 4A and 4B show further examples of cooperating attachment means;

Figures 5A to 5D show examples of humidification means;

Figures 6A and 6B show a different type of humidification means;

Figures 7A and 7B show a detachable patient enclosure coupled to an end portion;

Figures 8A to 8C show a door for use with an incubator in detail;

Figures 9A to 9C show stages in the replacement of incubator components;

Figures 10A and 10B show examples of IV mounting clips;

Figures 1 1 and 12 show examples of a mounting system for securing an incubator to a hospital bed or trolley;

Figure 13 shows some examples of air flow paths defined by a first and second chamber;

Figure 14 shows an example air flow path which extends below the patient enclosure;

Figure 15 shows two further air flow paths at the side of a patient enclosure and above the patient enclosure;

Figure 16 shows yet another air flow path;

Figure 17A illustrates a problem with enclosures which have no air circulation vents; and

Figure 17B shows an example of air circulation vents.

Turning now to Figures 1A and 1 B, there is shown a modular incubator 100, which comprises an end unit 102 and a patient enclosure 104. The end unit 102 is used to house the functional components of the incubator, for example air heating and circulation means (fans, heaters, etc.), electrical power, water supply and control. In Figure 1A the patient enclosure 104 can be attached and detached many times, for example to send it for sterilisation, or to remove an old one, and replace it with a new one. In this example, the entire patient enclosure 104 is reversibly attachable/detachable as set out in more detail below. In other words, the patient enclosure 104 is in this case a standalone unit in the sense that the entire enclosure 104 may be separable from the end unit 102, so that the entire patient enclosure 104 can be supplied separately and can be replaced as a whole unit. In this case, the patient enclosure 104 may not have any type of is a standalone flexible structure that is attached to the end unit 102 using a fastening method such as clips, zippers or hooks. In other examples, only a portion of the patient enclosure 104 may be detachable, removable and/or disposable.

In the example shown in Figure 1 B, the patient enclosure 104 has an inner liner 106 which is removable from the patient enclosure 104. This allows just the liner to be replaced, thereby speeding up the replacement process. Once removed, a fresh liner 106 can be fitted, while the old liner 106 is sent for disposal or sterilisation. In some examples the entire patient enclosure 104 is removable, and the patient enclosure has a removable liner 106.

The inner liner 106 may be secured inside the patient enclosure 104 by any suitable means, for example hook and look fastening systems, releasable adhesives, zips, buttons, clips, poppers, etc.

In some examples, there may be two end units 102, which attach to the patient enclosure. In general, each end unit may be modular and exchangeable. Broadly, each end unit 102 may attach in the same way as each other, and provide the same, complementary, or overlapping functionality. Future references to "the end unit" should therefore be interpreted as "the or each end unit". In some cases, the two end units 102 may broadly face one another when attached to the patient enclosure 104, for example they may form opposite faces of a cuboid. In other examples, they may be adjacent to one another, for example they may be hinged together along one edge, and open much like a briefcase to provide two broadly perpendicular attachment points for the patient enclosure 104. In this latter example, the overall shape of the incubator when assembled could be cuboidal, with the end units 102 on adjacent faces, or shaped like a quarter of a cylinder, depending on the shape of the patient enclosure 104. The patient enclosure 104 may be made of a flexible material, for example plastics or rubber materials. It is useful for the material to be water- and air-tight to ensure that the environment inside the enclosure 104 can be maintained with minimal work. In many cases, the patient enclosure 104 is also transparent, to allow visual monitoring of a patient without disturbing the internal environment. In some cases, the patient enclosure 104 is collapsible, to allow it to be stored in a compact manner, and then expanded when in use to a suitable size for treating a patient. The enclosure 104 may be inflatable, for example by virtue of a double walled construction, in which a gap between the two walls is inflated to provide rigidity. Alternatively, the interior of the patient enclosure 104 may be inflatable in the sense that it is designed to hold a positive pressure, which in turn holds the enclosure 104 in the expanded state. In many cases, since the patient enclosure 104 may be discarded after use, it may be made from a readily recyclable material, so that the environmental impact of use of the incubator 100 is reduced.

Figures 2 A to 2C show further modifications to a flexible patient enclosure 204 to assist in forming an assembled incubator 200. In some cases, it can be difficult to attach the patient enclosure 204 to the end unit 202. For this reason, the patient enclosure 204 may include a rigid portion 208, for example a planar sheet made from rigid plastics or metals. Plastics may be preferred materials for reasons of strength and cost. The rigid inset 208 may be attached to the patient enclosure 204 by placing the insert 208 into a pocket 210. The pocket may then be sealed, as shown in figure 2C by operating a catch 216 to hold the insert 208 in place. Alternatives to the catch are hook and look fastening systems, releasable adhesives, zips, buttons, clips, poppers, etc. In each of these cases, the insert 208 is easily removable from the patient enclosure 204.

Alternatively, the insert 208 may be permanently attached to the patient enclosure. For example, they may be either formed integrally with the enclosure, or they may be bonded to the enclosure by means of adhesives, welding, or the like. This may occur by welding the insert 208 directly to the enclosure 204, or it may be performed as above by first inserting the insert 208 into a pocket 210, and then welding 212 the pocket 210 shut. In other examples the rigid inserts may be permanently mechanically fixed to the enclosure by screws, rivets, staples and the like. In the bonding or welding examples, the rigid material will be made of a compatible material, e.g. one which can be bonded or welded to the material of the enclosure 204. This may mean that the rigid insert 208 is made from the same material as the enclosure 204. In other cases, e.g. where the enclosure 204 must be flexible but the inserts 208 must be rigid, it may not be possible to make both from the same material, but a pairing can be chosen by consulting a known list of compatible materials. Rigid portions (whether integral or in the form of inserts) can help parts of the enclosure to retain their shape. In the case of permanently bonded rigid portions, less material is used overall for the patient enclosure whilst keeping the rigidity of using an insert. In any of the above examples, the insert 208 may include protrusions 214 for assisting in attaching the patient enclosure 204 to an end portion 202. In cases where protrusions 214 are used, the pocket 210 may have slits or holes in appropriate places to allow the protrusions 214 to pass through the walls of the pocket 210.

Figures 3A to 3D describe a series of means for reversibly attaching the patient enclosure 304 to an end unit 302 to form an assembled incubator 300. In general a patient enclosure 304 is brought towards an end unit 302 as shown in Figure 3A (see the arrow, for example). Also as shown in figure 3A, there may be a recess in the end unit 302 to ensure that the patient enclosure 304 is correctly aligned with the end unit 302. This may be important, for example to ensure that any outlets form the end unit 302, e.g. for warm air, are aligned with any inlets on the patient enclosure 304. The arrangement of the inlets and outlets and the shape of the recess and any protrusions on the insert 308 may be arranged so that there is only one alignment between the patient enclosure 304 and the end unit 302 which will fit, so that it is impossible to attach these two in the wrong orientation.

Figure 3B shows for example a button system, comprising a protrusion 318 having a broadly T-shaped cross section. The protrusion 318 is arranged to fit through a wide part of an eye hole 320 in the patient enclosure 304. Once the protrusion 318 has been inserted, a lateral relative movement between the protrusion 318 and the eye hole 320 locks the two parts together, as the arms of the T-shaped protrusion 318 cannot fit through a narrow part of the eye hole 320. This attachment system can be used with or without a rigid insert. In Figure 3C, a different system is shown, in which a rigid insert 308 is held in place by rotatable clips 322. In this example, the clips 322 have the shape of quarter circles, and are rotatable about the centre of the circle. In some embodiments, the clips may have a different shape, such as semi-circular, or polygonal. In any case, the clips are rotated such that they do not block the path of the rigid insert 308, when it is pushed towards the end portion 302, as shown by the arrow in Figure 3A. This is shown in the lower left portion of Figure 3C. Once the rigid insert 308 is correctly located adjacent to the end unit 302, the clips 322 are rotated, where they engage the rigid insert 308 (possibly engaging with a protrusion of the insert 308), and prevent the insert from being removed, as shown in the lower right portion of Figure 3C.

Figure 3D shows yet another attachment means. In this case, the end unit has clips 324a and the rigid insert 308 has portions (which may be integral or protrusions) 324b for engaging with the clips. The rigid insert 308 may be slid into place, where the clips 324a prevent further movement. The clips 324a may be sprung to exert a gripping force on the corresponding portions 324b rigid insert 308, and the insert 308 may even have recesses for seating the clips correctly, and inhibiting unwanted relative movement between the patient enclosure 304 and the end unit 302.

In each of these cases, the method for detaching the patient enclosure 304 from the end unit 302 is broadly the same steps, carried out in reverse. Figures 4A and 4B show yet another example of attachment means for assembling an incubator 400. In this example, the patient enclosure 404 has a flexible end portion and the end unit 402 has a rigid lip 426 protruding outwards. The end portion of the patient enclosure 404 is simply stretched over the lip 426, where the deformation of the patient enclosure during the stretching process provides a gripping force to hold the patient enclosure 404 on the end unit 402. To assist the deformation and gripping, the end portion may be made from an elastic material. While the patient enclosure 404 shown in Figures 4A and 4B is circular in cross-section, the cross-sectional shape may actually be any shape, for example, square, rectangular, triangular polygonal or irregular, depending on the context. In many cases, incubation treatment includes providing a controlled humidity environment, particularly in cases where the air for incubation is drawn from a local environment which is not itself climate controlled. In Figures 5A to 5D steps of a method for providing humidity to the patient enclosure 504 are shown. In Figure 5A, a container 528 of sterile water 530 is inside the patient enclosure 504. No humidity change is seen because there is a cap 532 on the container 528. The container 528 may be formed as part of the enclosure 504, or it may be supplied separately, and mounted in the enclosure 504 only when needed, for example by using hook and look fastening systems, releasable adhesives, zips, buttons, clips, poppers, etc. In any case, it may be supplied full or empty, for filling (and refilling) with sterile water in situ.

In Figure 5B, the cap 532 is being removed, to allow the water 530 to contact the air on the interior of the patient enclosure 504. The water begins to evaporate, as shown in Figure 5C, where water vapour or humidity 534 has suffused into the air of the patient enclosure 504. After some time (Figure 5D), two things have occurred. First, the evaporation has slowed from an initial high rate as the air becomes more humid and equilibrium is achieved. The level of water 530 in the container 528 has reduced accordingly. Second, the humidity has diffused throughout the patient enclosure 504 so that the atmosphere inside the enclosure is broadly homogeneous.

The rate at which water enters the atmosphere from the water 530 is dependent on many factors, such as temperature, pressure, etc. However, control of the evaporation rate (and thus the rate of humidification) can be controlled by adjusting the surface area over which the water can evaporate. For example, narrowing or widening the opening of the container can lower or raise the evaporation rate respectively. Alternatively a perforated cover (not shown) could be placed under the cap 532, so that when the cap 532 is removed, there is less surface area of the water exposed, and the evaporation rate is reduced. In the event that a higher rate is desired, the surface area can be increased using a wick, a sponge or a porous material (all not shown), which can adsorb water over a large surface area to increase the evaporative rate. The container can be supplied with different attachments of this type to adapt to the desired conditions.

Figures 6A and 6B show another humidification means for use in an incubator 600. A humidifier 636 is placed in the patient enclosure 604. This humidifier may be provided as part of the patient enclosure 604, or it may be a separate item to be placed in enclosures 604 when required. The humidifier 636 may be self-contained, e.g. battery powered and having its own on board water source (which may be refillable), or it may be connectable to water and/or electricity supplies (e.g. provided from an end unit). When switched on, the humidifier provides water vapour (or humidity) 634 to the interior, until it is switched off (or until the water supply runs out). The humidifier 636 may operate on a timer or on a duty cycle, in which it switches on and off to maintain a particular selected level of humidity. The humidity level may be controllable on the humidifier 636. Additionally, or alternatively, the humidifier may make use of set points, feedback loops and/or humidity sensors to determine when to turn on or off, and how long for.

Each of these humidification means can be used with any incubator, and not just the specific examples described herein.

Turning now to Figure 7, an incubator 700 is shown for use with a variety of medical scanners. In this example, the patient enclosure 704 is reversibly attachable to an end unit 702, for example by one of the attachment means described above. When the patient needs to undergo a medical scan, for example an MRI scan or a CT scan, the incubator can be brought close to the scanner, but traditionally, the patient would need to be removed from the enclosure 704, thereby endangering their health. The present example includes couplings 738 between the end unit 702 and the patient enclosure, for example to carry water, warm air, or electrical power to the patient enclosure. The couplings are of sufficient length to allow the end unit, for example containing delicate equipment which could be damaged by stray magnetic fields, X-rays, etc., to be positioned a safe distance from the scanner, while the patient 742 can be placed inside the scanner, inside the protective environment of the patient enclosure 704. The arrangement of couplings such as these could apply to any incubator and not just the specific examples described herein.

Turning now to Figures 8A to 8C, a door specially designed for use with incubators 800, including those described herein, but applicable to all incubator designs, is shown. The door comprises two panels, an upper panel 844a, and a lower panel 844b. The upper and lower panels 844 are hinged together by a hinge 846b and are hingedly connected to the patient enclosure by a hinge 864a along one edge. When a patient is placed inside or taken out form the patient enclosure 804, a large door is required, so the hinge along one edge 846a is used. For routine checks on the patient, only the hands of a medical practitioner need enter the enclosure 804, so a smaller opening is made by using the hinge 846b connecting the two panels 844 together. In order to maintain the upper panel 844a in place, a toggle connection 848 may be used (as shown in Figure 8C), in which a protrusion 850 is slid through a corresponding hole 852 to connect the door to the patient enclosure 804.

While the door shown is generally rectangular, any shaped door can be used, for example trapezoidal doors. While the hinge 846b which joins the two panels 844 is shown as being parallel to the hinge along one edge 846a, these may be arranged at any angle to one another, according to the specific implementation. Indeed, the two panels 844 need not be the same size or shape as one another. The door may extend across all (or substantially all) of one surface of the patient enclosure 804. Alternatively, it may be much smaller than this.

As shown, the door is divided into two panels 844 by a hinge 846b which runs broadly horizontally. While any orientation of this hinge 846b is possible, it may be advantageous to provide a horizontal arrangement because when access is required to the interior during use, the lower panel 844b of the door can be opened, meaning that the warmer air inside, which tends to rise, is better retained inside the enclosure than if the opening were at the top of the enclosure 804. Consider now Figures 9A to 9C, which show steps in the method of replacing a broken fan and/or heater using a break out board 900. In Figure 9A, one or all of the fans 956a and heaters 958a originally forming part of the incubator (for example housed in an end unit) have been detected as having malfunctioned. This may occur either by an operator noting that the incubator is not functioning as intended, or by an error being detected by an on board monitoring and alerting system. Due to the malfunction, the break out board 900 has been removed from the incubator, for example by removing from a slot in the body of an end unit.

The next stage (Figure 9B) is to remove the original fans 956a and/or heaters 958a. These are connected to the incubator by use of plugs, sockets, pins, snap connections, etc., which are in any case simple to remove and connect, ideally requiring no special tools or equipment. In some cases, all equipment may be removed, and tested, even if was not the cause of the malfunction, to ensure that it is correctly operating.

Finally, any faulty fans are replaced with a new fan 956b and any faulty heaters are replaced with a new heater 958b. There may be more than one fan and/or heater on each board 900, and there may be more than one board 900 per end unit. Indeed, components other than fans and heaters may also be included on the break out board. Such a system could be applied to any type of incubator, and not just the specific examples described herein. Figures 10A and 10B show examples of means by which IV (intravenous therapy) lines may be provided in the incubator 1000. The patient enclosure 1004 has IV holders in the form of shaped clips 1060 moulded or permanently attached in the interior, including as part of an end unit, for example. An IV line 1062 can be placed with ease into such clips 1060. The enclosure 1004 may also include holes 1064 for inserting an IV line into, to access the interior.

In Figures 11 and 12, various methods of securing an incubator to a hospital bed or trolley 1170 are shown. A rigid base 1166 is shown spanning between two end units 1104. The base may have regions 1 172 for receiving a strap 1 168, for example recessed portions or clips. One or more straps 1168 are secured around the base 1 166 and the bed or trolley 1 170 to hold the incubator in place.

Alternatively, as shown in Figure 12, the end portions 1204 may include slots strap retaining portions 1272, for receiving straps 1268. The straps 1268 may be fed through the retaining portions 1272 and tightened. For example, the retaining portion 1272 may include a pair of slots 1276 and a pin 1274. A strap 1268 is fed through the slots 1276 and when tightened, the pin 1274 ensures that it is kept close to the corner of the housing 1204. In the case where it is the end unit 1204 which attaches to the bed or trolley, there is no need for the base portion 1266. Instead, the end units 1204 can be secured to the bed or trolley at an appropriate separation for a patient enclosure to be fitted. Even when a base is provided, the base may be removable, to allow the incubator to be dismantled and stored in a compact manner. Alternatively, the base may be foldable, telescoping or otherwise collapsible, for example for storage in an end unit.

Turning now to Figure 13, a series of examples 1300 of two-chambered patient enclosures are shown. In a first example, the first chamber 1378 and second chamber 1380 are located adjacent to one another, so that an air gap is formed by three walls of the second chamber 1380 and part of a wall of the first chamber 1378.

A second example is very similar to the first example, and comprises the second chamber 1380 extending across an entire wall of the first chamber 1378 to provide an air gap. A third example is also shown in which an L-shaped air gap is shown as being formed by the second chamber 1380 extending across two walls of the first enclosure 1378. The final example shows the second chamber 1380 surrounding the first chamber 1378, creating a circumferential air gap. In each case, the interior of the first chamber 1378 is for receiving a patient, while the second chamber 1380 exists to provide an air gap adjacent to a portion of the first chamber. The provision of an air gap in this way can be applied to all designs of incubator, including the flexible, inflatable, double walled and collapsible designs described above. It can even be applied to designs other than those specifically described herein.

An air gap of this type can provide a flow path along a side of the first chamber 1378. An air flow path is a region bounded by one or more walls in which air can flow. It can be used to direct air flow between two points, for example and inlet and an outlet. In addition, the air flow paths described above (those defined by the air gaps between the first 1378 and second 1380 chambers) all run along an external portion of the first chamber 1378. Since warm air for delivery to the incubator runs along part of the exterior of the first chamber 1378, heat is delivered to the first chamber by conduction through the walls of the first chamber 1378. This arrangement helps to heat the first chamber 1378 in a more even manner. The air flow path itself will be determined by the arrangement of the second chamber 1380 relative to the first chamber 1378 and also the location of an inlet into the air gap and any outlets between the air gap and the interior of the first chamber 1378. If the goal is to achieve a good transfer of heat from the air as it passes, then arranging the inlet and any outlets in such a way that they force the air to flow over a large portion of the exterior will help to achieve this. Therefore, an air flow path is to be interpreted as a region in which air is constrained to retain it close to a wall of the first chamber 1378. The key features are that there is an inlet and an outlet, for example so that the inlet can be attached to an air source (a fan, compressed air, etc.) which causes the air to flow along the flow path. Conversely, the walls of the chambers, primarily the second chamber 1380, in addition to at least part of the exterior of the first chamber 1378 retain the air within the air flow path. For the avoidance of doubt, the term "air flow path" does not mean that air is necessarily flowing in the air path. Instead it is a structural feature in which air supplied through an inlet would be retained in the air flow path, following the path, with the two chambers 1378, 1380 acting much like a pipe or conduit, until it leaves by an outlet or aperture. In the examples provided herein, the outlet delivers the air into the interior of the first chamber 1378.

Figure 14 shows an example of the use of an air gap in more detail. Here, heated air enters the air gap from an inlet and flows 1482 along a wall of the inner chamber 1478, and is forced to take this path by the walls of the second enclosure 1482. After traversing the outside of the first chamber 1478, the warmed air enters the interior of the first chamber via an aperture 1484, which may be located in a corner of the inner chamber, or in one of the walls. In some cases there may be a plurality of such apertures 1484, for providing an even distribution of the air. Figure 14 shows three examples, each of which having an inlet towards the affront surface of the first chamber 1478 (left in the Figures) and having an air flow path extending towards the rear (right in the Figures) of the first chamber 1478. The first and second in which the air flows along only a single wall of the inner chamber 1478 (corresponding broadly to the second example in Figure 13) and a third example, in which the air flows along four walls of the first chamber 1478 (corresponding to the fourth example in Figure 13). Of course, any of the examples of Figure 13 may be applied here, including combinations of those examples.

In each of the examples in Figure 14, the air flow path extends from an inlet, along an entire length of the first chamber 1478. In the first example, the air flow path extends to the rear, and enters either through a plurality of apertures 1484 arranged along the lower back corner of the first chamber. An end view of this arrangement is shown to the right.

In a second example, the air flow path terminates in a large aperture in the rear surface for the first chamber 1478. This entails the air flow path lying adjacent to a portion of the rear surface of the first chamber 1478. A development of the first example is shown in the third example, at the bottom of Figure 14, in which the air flow path leads from the inlet, along four sides of the first chamber 1478, and then enters the inner chamber 1478 via a series of holes 1484 in the four rear corners of the generally cuboidal first chamber 1478. An example of the arrangement of such holes 1484 is shown to the right, which once again represents an end view of the system. The holes, or apertures 1484, are arranged in a row along each of the rear bottom, rear top, rear left and rear right corners of the inner chamber 1478.

Figure 15 shows two further examples of air flow paths, a first in which the air flows 1582 along one or both side walls of the first chamber 1578, and a second where the air flows 1582 along the upper surface of the first chamber 1578. In this second example, a plurality of apertures 1584 is arranged along the upper surface of the first chamber 1578. This means that the air enters all along the upper surface and some of the air does not traverse all the way along the first chamber 1578 before entering the first chamber 1578. It is a particular feature of this second example, however, that the apertures 1584 closest to the inlet (to the left of the Figure) are smaller than those further away from the inlet. Specifically, the size of aperture 1584 gradually increases with distance from the inlet (i.e. further to the right in the Figure). The exact manner in which size of aperture changes with distance from the inlet can be selected to provide a reasonably constant amount of air flow out of each aperture 1584, irrespective of proximity to the inlet. The lower right part of Figure 15 illustrates this effect. The effect of this arrangement is to increase the effect of heating through the walls, since the air spends more time flowing past the exterior of the first chamber 1578, due to the restricted flow path into the first chamber 1578 provided by the small apertures located close to the inlet.

Turning to Figure 16, another example of a flow path 1682 is shown, in which the air passes from side to side of the first chamber 1678, heating the walls as it passes. This arrangement provides flow across the entire lower surface, across the entire length of the device. A limited aperture size at the far end retains the warm air in the air gap for a longer time, promoting heating of the floor.

Finally, consider Figures 17A and 17B. In Figure 17A a patient enclosure 1704 is shown in normal use. Air enters through the inlet 1786 and circulates around the enclosure 1704 as described above, as shown by the solid arrows. In the event of a fan failure or other such event, no new air enters the enclosure 1704. In Figure 17B, this is addressed by the provision of an air circulation vent 1788 in the wall of the enclosure 1704. In this case, when the failure occurs, fresh air can enter the enclosure 1704 from the outside via the vent 1788 (shown by a dashed arrow to distinguish from the normal air flow paths). The vent 1788 may be a perforation or other aperture in the patient enclosure. The use of such a vent ensures that in a potential fault condition fresh air still enters the enclosure 1704.

While any location on the exterior of the patient enclosure 1704 is suitable for vent 1788 placement, some locations are preferred. For example, where the enclosure 1704 is largely flexible with a rigid portion, the vent 1788 can advantageously be provided in the rigid portion. This is because if the flexible portion collapses, the vents are more likely to remain open if they are in the rigid portion, but may become blocked by the collapsing enclosure 1704 if they are located in the flexible portion. In some cases, the vents 1788 may be located in parts of the enclosure to which it is otherwise difficult to ensure sufficient air flow. For example, in the example shown, it may be that it is found that a corner region of a cuboidal enclosure receives less air than other parts of the enclosure, yet air is desired in that region. The vent 1788 has been placed in that corner region so that air flows through the region as it leaks out of the vent 1788, as shown by the solid arrow leading out of the enclosure 1704.

Any such air circulation vents 1788 should be sized and shaped so as to ensure that they do not disrupt existing air flow paths. For example, a large hole would cause a leak out of the enclosure and greatly reduce the ability of the incubator to provide a climate-controlled environment. Even where such vents 1788 are part of the flow paths, as set out above, too large a hole can reduce the temperature to an unacceptable degree. Conversely, if the vent 1788 is too small, the beneficial effects may not be provided sufficiently to ensure patient safety. Multiple vents 1788 may be used in some cases, to ensure that the correct balance is struck. Depending on the size and shape of the enclosure, a variety of vent sizes and locations may be beneficially chosen to achieve the desired balance. It is within the skilled person's skills to determine a suitable vent distribution, sizing and shape for a given design, without undue experimentation.

Another manner in which the air flow paths may be preserved is to fit the vents 1788 with one-way flow elements (e.g. valves), not shown in the Figure. These would be configured to allow air flow into the enclosure, but not out. Since there is air flow into the interior of the enclosure in normal operation, the enclosure operates at a slight positive pressure. This means that such one-way elements on the vents 1788 would be held shut, and no air would flow out of them. In the event of a fan failure, no positive pressure condition exists and the valves would open, thereby fulfilling their safety function. In some designs which use this idea, only some of the vents 1788 may be fit with one-way flow elements. In other such designs all of the vents 1788 may be provided with one-way air flow elements.

In other words, these air circulation holes (i.e. the vents) are included in patient enclosure 1704 to allow for air to flow in and out passively. The air circulation vents 1788 mean that if all power is lost to the incubator then the holes act as a safety mechanism so that the patient always has access to oxygenated air in any type of scenario.

In any of the above examples, the patient enclosure may include an outlet (not shown) for recirculating the air. The outlet may be connected to a fan and heater combination to provide a small amount of top up heating of the air. The recirculated air may be blended with fresh air to ensure an adequate oxygen supply. Where more than one aperture is present, they may be arranged in a periodic arrangement (e.g. a regular array), or they may be situated in particular locations for advantageously providing homogeneous conditions, targeted heating etc.