This invention relates to an assembly suitable for facilitating insertion of a needle into a vein, and a support that forms part of that assembly.

Venipuncture is one of the most routinely performed invasive medical procedures and is vital for blood analysis diagnostic tests and for administering certain therapeutic treatments including chemotherapy. However, it is not always straightforward to locate and puncture a suitable vein. Multiple attempts to locate a vein in a patient can be painful and distressing, especially for small children and people with a fear of needles.

Devices which aid in locating veins are known. A recent development is to use infrared (IR) light to create an image of the area of a patient's skin into which a needle is to be inserted. As haemoglobin in the blood absorbs infrared light, the position of veins or other blood vessels can be clearly seen when imaged with IR light.

However, many devices which use IR to image veins are not portable as they comprise a large screen which is freestanding and located at a distance from the patient. These devices require a considerable degree of skill and hand/eye coordination on the part of the user to be able to match the image on the screen to the relevant point on the patient's skin. These devices are also expensive. Although some portable IR imaging devices are known, these devices are difficult to use and, unless the phlebotomist can hold the device steady in one hand whilst inserting the needle with the other, require two technicians so that the device to be supported at the same time as the needle is inserted. Although cheaper than the large freestanding devices, the portable devices are nonetheless expensive.

There therefore remains a requirement for a portable vein locating device which is less expensive than the currently available devices whilst being more convenient for a single user to operate. According to the invention, there is provided an assembly for facilitating the insertion of a needle into a patient's vein, the assembly comprising

an imaging device adapted to display an infrared image of an area of the patient's skin overlying the vein; and

an imaging device support having a base adapted to be positioned on the patient at or adjacent to said area of the patient's skin, and a cradle held in spaced apart relationship from the base, the cradle being adapted to receive the imaging device;

the arrangement being such that, in use, the imaging device displays an infrared image of the area of the patient's skin, in which image veins beneath the skin and a needle brought into proximity with the skin are apparent, so that insertion of the needle into the vein is facilitated. This assembly is particularly advantageous as it provides the operator with an infrared image of the vein into which the needle is to be inserted in close proximity to the area of the patient's skin where the vein is situated, without it being necessary for the operator to hold the imaging device. This facilitates the insertion of the needle into a patient's vein as the operator can view an image of the relevant area in very close proximity to, and preferably directly above, the point at which insertion of the needle is to take place and has both hands free to perform the needle insertion.

Infrared light is particularly suitable for imaging veins as the haemoglobin in red blood cells absorbs infrared light light more strongly than the surrounding tissue. The veins therefore appear darker than the surrounding skin in an infrared image and are clearly visible.

By "infrared" is meant the region of the electromagnetic spectrum commonly referred to as such. Typically that region encompasses radiation with a

wavelength of about 700 nm to about 1 mm. Types of infrared radiation that of particular utility in the present invention are the "near infrared", by which is meant the region of the electromagnetic spectrum commonly referred to as such, and which typically encompasses radiation with a wavelength of about 0.75 μιη to about 3 μιη, and the short-, mid- and long-wavelength infrared, which respectively encompass radiation with a wavelength of about 1 .4 μιη to about 3μιη, about 3 μιη to about 8 μιη, and from about 8 μιη to about 15 μιη.

In practice, different detectors within cameras will work at different wavelengths. However, in general there are two main categories of cameras that can be used in this invention and that are currently available:

a) Infrared thermography cameras work in the region of about 8 to 15 um

(Long Wave Infrared; LWIR). This technology can detect objects at different temperatures with a wide range of applications including temperature measurement, long distance night vision, buildings insulation, medical applications, etc.

b) Near-infrared (about 0.75 to 1 .4 um ) are used in vein locator systems, security night-time surveillance cameras (with support of near infrared light or illuminator).

This invention, in additional to visual cameras, covers near infrared (NIR) and LWIR (thermal imaging). However, other detectors and cameras can be developed to cover other parts of the infrared spectrum and hence the invention is not limited to the above ranges of frequencies. In near infrared technology (as for most vein locator systems available in the market) near infrared light or

illumination will be needed to enhance the vision of the detector/camera. With the thermal camera (LWIR), a cold press (cold stimulation) will normally be needed to enhance the detection of veins due to the change in thermal characteristics between tissues and the circulating blood in veins and/or the difference in the thermal capacity.

Preferably the imaging device is orientated in relation to the patient such that the image of the vein site is provided directly above the vein site. The operator can then easily align themselves with the device such that the image on the device is in the operator's line of sight when inserting the needle into the vein. Preferably the imaging device displays real time infrared video images of the area of the patient's skin. This is advantageous in that the image can then show the needle and its position relative to the vein as the needle is inserted. The operator can thus use the displayed image alone to insert the needle without having to look directly at the patient's skin.

Preferably the imaging device is a smartphone or tablet computer. Suitable hardware/infrared cameras and software can be added to modify standard smartphones or tablet computers to produce and display infrared images.

Moreover, standard smartphones and tablet computers can be modified by replacing or modifying part of the hardware, such as the camera, to enable it to detect infrared radiation. Smartphones and tablet computers are available to purchase at significantly lower cost than purpose-made electronic displays and integrated devices. The overall cost of the assembly can therefore be significantly lower than that of currently available infrared vein imaging devices. To reduce the cost further the operator may use their personal smartphone or tablet computer providing the smartphone or tablet computer has the appropriate

hardware/software additions or modifications. The smartphone or tablet computer can then be inserted into the cradle of the support by the operator immediately before use.

The cradle may be adapted to accommodate a particular imaging device or, as many smartphones and tablet computers have similar dimensions, the cradle may have suitable dimensions to accommodate most conventional smartphones or alternatively most conventional tablet computers.

Typically the cradle will be a shallow rectangular housing formed with appropriate openings such that the imaging device can be inserted and then be operated normally, ie the camera is not obscured, and the operator is able to manipulate the imaging device, ie the screen and any operating buttons are not obstructed.

The cradle may further comprise a means for retaining the imaging device in the cradle after the imaging device has been inserted into the cradle. For example the cradle may further comprise a protrusion, eg of resilient material, that projects from an edge of the opening through which the device is inserted. The device can pass the protrusion when inserted but the protrusion is shaped such that it prevents the device from coming out of the cradle unintentionally. Other suitable means for retaining the imaging device in the cradle will be apparent to the person skilled in the art.

The cradle may be constructed from any suitable material. Preferably the cradle is constructed from a suitable plastics material. Suitable materials will be apparent to those skilled in the art.

The cradle may be connected to the base by any means suitable for keeping the cradle and the base in the desired spaced apart arrangement. Preferably the cradle is connected to the base via a support column arranged perpendicular to the base. The support column may be adjustable such that the cradle may be movable relative to the base. For example the cradle may be rotatable about the support column. This allows the position of the cradle and hence the imaging device to be adjusted to optimise the image viewed on the imaging device for insertion of the needle into the vein. In addition, the cradle may be rotated through 180° and out of the field of view of the needle insertion site. This allows further procedures to take place if required whilst the support is still in situ.

In addition or alternatively, the height of the column may be adjustable. For example the column may be telescopic. This allows the distance between the imaging device and the patient to be adjusted. This is beneficial if the focussing distance needs to be altered or if a larger or smaller area of the patient's skin needs to be imaged.

The base is preferably generally U-shaped and is most preferably formed of two elongate members and a cross bar that connects the two elongate members. In use the elongate members of the U-shape preferably extend along the axis of the patient's limb. The base is preferably connected to the cradle at a point on the base located on the cross-bar of the base. This arrangement allows the support to be more balanced as, in use, the cradle would normally extend parallel to the elongate members of the base.

The elongate members of the base may be adaptable to conform to the differing dimensions of patients' limbs. For example, the elongate members may be slidably connected to the cross bar such that the distance between the members may be adjusted. Alternatively, or in addition, the elongate members may be pivotably connected to the cross bar such that by varying the angle at which the elongate members are positioned, the distance between the ends of the members distant from the cross bar may be varied.

The elongate members of the base may alternatively or additionally be formed from a deformable material such that they can be formed into any desired configuration. It would be understood by the person skilled in the art that the elongate members may incorporate all or any combination of the above-mentioned features. By using a combination of these features, the adjustability of the elongate members can be optimised.

In addition, the base may be provided in more than one size, for example a base suitable for a child's limb and a base suitable for an adult's limb, such that the degree of adjustability required is lower and the support can be constructed in a more compact manner.

The base may be constructed from any suitable material. Preferably the base is constructed from a suitable plastics material. Suitable materials will be apparent to those skilled in the art. The base and the cradle may be formed in the same or different materials.

The support may be secured in position on the patient by any suitable means but preferably the support is held in place by means of a strap. A strap is particularly advantageous as it may also act as a tourniquet and thus further aids in locating the vein of the patient.

The strap is preferably connected to the base of the support. Preferably the strap is connected to the support by passing the strap through apertures formed in the base. This arrangement is advantageous as the strap is located in close proximity to the patient's skin and thus can easily act as a tourniquet. In addition, the strap cannot easily be removed from the support in this arrangement and is therefore less likely to be misplaced. The strap may be formed of any suitable material but preferably the strap is a fabric strap. A fabric strap can be comfortable for the patient whilst being inelastic enough that it can act as a tourniquet.

The strap may be fastened around the patient by any suitable means but preferably the strap is fastened in place by means of a connector provided at at least one end of the strap, for example a hook-and-loop fastener or a buckle. Most preferably the strap is fastened in place by means of a buckle.

The image shown on the device may be a near infrared image or an image generated using radiation of another wavelength within the infrared, or such an image overlaid with a visible light image.

If near infrared light is used, the wavelength of the illuminating light is preferably 750-950 nm. Preferably a combination of two or more specific near infrared illumination wavelengths may be used. This is beneficial as it improves the clarity of the near infrared image.

If the image to be shown is an infrared image, the support may be provided with a means of cooling the area of the patient's skin to be imaged. By cooling the skin, the contrast in the image between the veins and the surrounding skin is increased aiding location of the veins. The cooling means may be any suitable cooling means but preferably the cooling means is a compressed gas or compressed fluid supply. The cooling means is connected to the cradle of the device such that it may be directed toward the area of skin to be imaged. Preferably the cooling means is connected to a side of the cradle.

Alternatively the area of the patient's skin to be imaged may be cooled with a cold compress before the area is imaged.

The support may be provided with an additional light source. The additional light source may be an infrared light source, an LED light source to illuminate for near- infrared, or alternatively a visible light source to aid conventional imaging of the area. It is particularly advantageous to overlay an infrared or near infrared image with a conventional camera image so that the needle to be inserted can also be shown in the image, enabling the position of the needle relative to the vein to be determined from the image alone. The additional light source may be connected to the cradle of the device such that it may be directed toward the area of skin to be imaged. Preferably, the additional light source is connected to a side of the cradle. Preferably, the additional light source is provided with an independent power source, for example a battery. It will be appreciated that the support of the present invention may be suitable for use in supporting devices other than an imaging device. Therefore, in a second aspect, the invention provides a support for a medical device, the support comprising

a base adapted to be positioned on a patient at or adjacent to the desired area of the patient, a cradle held in spaced apart relationship from the base, the cradle being adapted to receive the medical device, and an attachment means for holding the support in position on the patient;

the arrangement being such that, in use, the medical device is held in a desired position relative to the patient without the need for the operator of the device to hold the device or the support.

It will be appreciated that this support may have any of the features discussed above in relation to the imaging device assembly. In another aspect, the invention provides a method for facilitating the insertion of a needle into a vein, the method comprising

a) positioning a support according to the second aspect of the invention on a patient, adjacent to the intended site of insertion of the needle;

b) engaging an imaging device with the cradle of said support; and c) using said imaging device to create an infrared image of the intended site of insertion of the needle;

whereby veins at the intended site of insertion of the needle are visualised in said image and insertion of the needle is thereby facilitated.

Steps a) and b) may be carried out in any order.

The imaging device may be, as described above, a smartphone or tablet computer.

Thus in another aspect, the invention provides a smartphone or tablet computer having an application for generation of an infrared image of an area of a patient's skin adjacent to which the smartphone or tablet computer is positioned in use.

The invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first embodiment of an imaging device support according to the invention;

Figure 2 is a view similar to Figure 1 , with an imaging device in place;

Figure 3 shows the assembly of Figure 2 in use, such that a vein in the patient's arm can be seen on the screen of the imaging device; Figure 4 is a view similar to Figure 2, showing a second embodiment of an imaging device support, where the support additionally comprises a cooling device; Figure 5 is a view similar to Figure 2, showing a third embodiment of an imaging device support, where the support additionally comprises a light source;

Figure 6 shows schematic side elevations of the imaging device support of Figure 1 , illustrating ways in which the support may be adjusted, in use; and

Figures 7 to 9 show further schematic views illustrating ways in which an imaging support device according to the invention may be adjusted, in use.

Referring first to Figure 1 , a first embodiment of an imaging device support according to the invention is generally designated 10, and comprises a cradle 1 1 for retaining an imaging device, a support column 12 and a base 13 for supporting the device on a patient. Typically, the support 10 is applied in use to the patient's arm or leg, and further comprises a strap 14 that holds the support 10 in place on the patient's limb, and when tightened may also function as a tourniquet.

The cradle 1 1 for retaining the imaging device is a shallow rectangular box of dimensions suitable to closely retain the intended imaging device. In currently preferred embodiments of the invention, the imaging device is a smartphone, tablet computer or the like, and the cradle 1 1 is dimensioned appropriately, for example (where the imaging device is a smartphone) ~1 cm deep, ~12cm long and ~7cm wide. One end of the compartment is open and constitutes an opening 16 through which the imaging device 20 can be inserted, as shown in Figure 2. The cradle 1 1 may be dimensioned and configured specifically to accommodate a particular type of imaging device, for example an iPhone 6 or an iPad mini.

Alternatively, the cradle 1 1 may be capable of accommodating any one of a range of imaging devices, eg any smartphone having dimensions within certain limits. In the embodiment of Figures 1 and 2, the cradle has a resilient protrusion 17 that extends from an inner edge of the opening 16 and serves to hold the imaging device 20 in a fixed position within the cradle 1 1 .

An opening 18 is provided in the base of the cradle 1 1 to coincide with the camera lens of the imaging device 20. The top of the cradle 1 1 is open, to allow the display screen of the imaging device 20 to be viewed. A further opening 19 is provided in the side wall of the cradle 1 1 to allow access to the controls of the imaging device, as shown in Figure 2. The base 13 is generally U-shaped, comprising a pair of elongate members that, when the support 10 is applied to a patient's limb, extend parallel to the axis of that limb. The strap 14 passes through apertures 15 formed in the elongate members, close to the ends of those members at which they are connected by a transverse bar. The strap 14 is typically a fabric strip with a buckle 21 for fastening the strap 14 once it has been passed around the patient.

The support column 12 extends between the underside of the cradle 1 1 (at the end distal to the opening 16) and the bar that connects the ends of the elongate members of the base 13, and maintains the cradle 1 1 and the base 13 in a spaced apart relationship.

As described above, the imaging device 20 is typically a smartphone adapted to be able to create an image using IR light. The imaging device 20 may be supplied by its manufacturer with such a capability, or software may be loaded onto the device 20 (eg as a downloadable "app") to create that capability.

Figure 2 shows the assembly of imaging device 20 and imaging device support 10. The imaging device 20 may be inserted into the cradle 1 1 either before or after the support 10 has been positioned on the patient's limb and fastened by tightening of the strap 14 around that limb. The imaging device 20 may then be used to generate an image of the patient's skin beneath it, using IR light, as shown in Figure 3. The position V of a vein in the patient's limb is shown in Figure 3, though in practice the vein may be difficult to see. The image I of the vein shown on the screen of the imaging device 20, on the hand, is clearly defined. As a needle is brought close to the patient's skin, its position relative to the vein is clearly visible in the IR image, and the needle can be precisely introduced into the vein. In order to facilitate the location of the patient's veins further, the support 10 may be provided with a compressed air or fluid container 22, as in the embodiment shown in Figure 4. Compressed air or fluid can be sprayed onto the patient's skin to cool the relevant area. Cooling the skin aids imaging of veins using infrared technology by providing a thermal difference between tissues and blood vessels.

Alternatively or in addition, the support 10 may be provided with a light source 23 to illuminate the patient's skin, as shown in Figure 5. The light source 23 may emit IR light and/or visible light to enhance the image of the patient's veins and to facilitate correct positioning of the needle, particularly if the support 10 is being used in an area with low levels of lighting or if the support 10 itself is casting a shadow over the area to be imaged. Such a light source may alternatively be incorporated into the imaging device, as a flashlight or torch function is commonly provided in a smartphone or tablet computer. Figure 6 illustrates how the configuration of an imaging device support of the invention may be adjusted. In Figure 6(a), the support has the configuration shown in the preceding Figures. Figure 6(b) illustrates how the cradle 1 1 may be swivelled through 180 ° , about the support column 12 to allow the position of the cradle 1 1 above the patient to be optimised for vein location and also for the cradle 1 1 to be rotated out of the imaging area if further procedures are required whilst the base 13 and strap 14 remain in position. Figure 6(c) shows how the support column 12 may have a telescopic design, allowing the separation of the cradle 1 1 and base 13 to be varied. Figures 7-9 illustrate how the shape and dimensions of the base of an imaging device support according to the invention may be adjusted to better conform to the shape of a patient's limb to which the support is applied. Figure 7 shows how the base may be constructed such that the spacing between the elongate members may be varied, by virtue of them being slidably mounted on a bar that connects them. Figure 8 illustrates how the elongate members may be flexible and capable of being bent to provide a better fit to the patient's limb, and Figure 9 shows how the elongate members may be pivotally connected to a bar that connects them. Of course, a support of the invention may incorporate any one, some or even all of the adjustment features described with reference to Figures 6 to 9.