Technical Field

The present invention generally relates to a head wearable air purifier apparatus. More specifically, the present invention relates to a head wearable air purifier apparatus capable of selectively measuring components of an exhaled breath of a wearer.

Air pollution is an increasing problem and a variety of air pollutants have known or suspected harmful effects on human health. The adverse effects that can be caused by air pollution depend upon the pollutant type and concentration, and the length of exposure to the polluted air. For example, high air pollution levels can cause immediate health problems such as aggravated cardiovascular and respiratory illness, whereas long-term exposure to polluted air can have permanent health effects such as loss of lung capacity and decreased lung function, and the development of diseases such as asthma, bronchitis, emphysema, and possibly cancer.

In locations with particularly high levels of air pollution, many individuals have recognised the benefits of minimising their exposure to these pollutants and have therefore taken to wearing face masks with the aim of filtering out at least a portion of the pollutants present in the air before it reaches the mouth and nose. There have also been various attempts to develop air purifiers that can be worn by the user but that do not require the wearer’s mouth and nose to be covered. An exhaled breath of an individual may contain biomarkers for certain pathologies such as lung cancer, asthma, chronic obstructive pulmonary disease, and others. Further, characteristics of the exhale itself such as force or speed may be indicative of other heath characteristics of the user. Measurement of various components of a wearer’ s exhaled breath is therefore desirable. Summary

According to a first aspect of the present invention, there is provided a head wearable air purifier apparatus comprising: a headgear; an air purifier assembly; a nozzle assembly coupled to the headgear for delivering purified air from the air purifier assembly to a wearer; a collection chamber for receiving at least a portion of exhaled breath; and a sensor configured to measure at least one component of the portion of exhaled breath; wherein the sensor is located in the collection chamber and the collection chamber comprises a one-way valve configured to selectively allow exhaled breath therethrough.

Measuring components of the breath of a wearer can be useful for overall heath monitoring. So that precise and reliable measurements can be achieved the head wearable air purifier apparatus selectively allows at least a portion of exhaled breath through to the sensor in a collection chamber. The selective allowance of only exhaled breath through the one-way valve may advantageously create a flow of exhaled breath through the collection chamber that reduces ambient air from outside the apparatus inflowing into the collection chamber and disrupting measurements made by the sensor. The collection chamber may be a tube or other vessel through which an exhaled breath can pass. Although described as a sensor throughout the specification, some example apparatuses may optionally include a plurality of sensors capable of monitoring a variety of components of the portion of exhaled breath.

Optionally, the collection chamber includes a further one-way valve. The further one-way valve may be positioned between the one-way valve and an outlet. The inclusion of a further one-way valve may allow for a shorter distance between the valves, as there can be a reduced risk of an ingress of ambient air to the sensor. As such, the distance between the sensor and an outlet may be shorter than if relying on a single valve and a relatively long distance to the outlet. As such, the apparatus may be made more compact, which may be beneficial on a small head worn device.

Optionally, the one-way valve is configured to actuate in response to breath forces produced by the wearer. Advantageously, by having a valve opening and closing in response to the breath force of an inhale or exhale, the need for electronic operation of the valves may be negated. Thus, the efficiency of the system may be increased.

Optionally, the further one-way valve is configured to actuate in response to breath forces produced by the wearer. The exhaled breath of the wearer may exert a push force on the one-way valve, which can cause it to open. In some examples, the inhale breath of a wearer may exert a pull force on the valve such that on an inhale breath the valve is drawn closed. Optionally, one or both of the one-way valve and further one-way valve may be configured to open in response to an exhale breath force from lOPa to lOOOPa. Optionally, one or both of the one-way valve and further oneway valve are configured to close in response to an inhale breath force of lOPa to lOOOPa exerted thereon. The valves being tuned to the forces of inhale and exhale breath may increase the selectivity of the valves which in turn allows for more precise measurements by reducing unintentional ingress of ambient air.

Optionally, one or both of the one-way valve and further one-way valve are biased to a closed position, such that the one-way valves return to a closed position during an inhale breath of a wearer. Biasing the valve(s) to a closed position may increase the speed the valve(s) close, which may in turn reduce ambient air reaching the sensor and thereby increase the precision of the measurements. One or both of the valves may be biased by a respective resilient member. Alternatively, or in addition, one or both of the valves may be formed of a resilient material, for example rubber. The material of the valves may therefore provide the biasing force towards to closed position. In these examples, an exhaled breath of a wearer may be sufficiently forceful to overcome the bias such that the valve is selectively opened in response to an exhale breath then returned to a closed position during the inhale breath of the wearer. Optionally, at least one of the one-way valve or further one-way valves may be a flap valve. Although described throughout the specification as a singular flap actuating about a single pivot point, the valve may be any form of one-way valve, such as a circular valve.

Optionally, the sensor is positioned downstream of the one-way valve, such that the portion of exhaled breath passes through the one-way valve before being measured. Placing the sensor downstream of the one-way valve may allow the actuation of the one-way valve to reduce ambient air reaching the sensor from a wearer facing side of the nozzle assembly. In some examples, the sensor is positioned within the collection chamber such that the sensor may be disposed between the one-way valve and the further one-way valve. The sensor may therefore be contained in a sub-chamber formed in the collection chamber between the one-way valve and the further one-way valve. Optimising the sensor’s positioning between the one-way valve and the further oneway valve may mitigate the likelihood that the sensor will be exposed to ambient air which can reduce the precision of any measurements.

Optionally, the sensor is disposed closer to the one-way valve than the further one-way valve. While the further one-way valve may allow for a reduced distance between the sensor and the outlet there may be some slight ingress of ambient air from outside the device, predominantly due to the closing of the valves not being instantaneous. The air which would ingress around the one-way valve is air already contained within the sub-chamber, which is an exhaled breath. Whereas the air which would ingress around the further one-way valve may be ambient air. So, positioning the sensor closer to the one-way valve may mitigate at least some of the chance of ambient air influencing the measurement, which improves the precision of the obtained data.

Optionally, the nozzle assembly includes an inlet for directing an exhale breath to the collection chamber. The inlet may allow the one-way valve to be positioned back from a user-side face of the nozzle assembly, this may provide a degree of protection to the one-way valve, reducing damage when removing the headgear for example. Further, setting the one-way valve back from the user-side face may reduce the chance of an external force (wind for example) actuating the valve thereby resulting in false readings. Optionally, the inlet may be positioned on a central portion of the nozzle assembly, such that in use the inlet is at least partially in front of a wearer’s mouth. Optionally, the inlet is positioned adjacent to an air outlet for emitting filtered airflow from the nozzle assembly. The inlet position may be above or below the air outlet such that the inlet is mostly central on the nozzle assembly, whilst allowing for central placement of the air outlet for optimised inhale for a wearer.

Optionally, the apparatus includes multiple inlets around the central portion of the nozzle assembly. The multiple inlets may link to the collection chamber such that only a single one-way valve is needed, or each inlet may include a one-way valve. In some examples the further one-way valve may be integral with the outlet and or the one-way valve may be integral with the inlet.

Optionally, the collection chamber is located within the nozzle assembly. In some examples the collection chamber may be defined by interior walls of the nozzle assembly. Advantageously, the collection chamber may therefore be positioned close to the wearer’s mouth in use. This may allow for reduced dissipation of the exhaled breath at the sensor improving the measurements taken by the sensor. In other examples the collection chamber may be removably attached to the nozzle assembly. Optionally, the collection chamber is located in or on the headgear. Optionally the collection chamber is removable from the nozzle assembly or headgear, so that the collection chamber can be cleaned for example. A removable collection chamber may also optionally allow for interchanging different chambers which include sensors capable of measuring different types of components of exhaled breath. Optionally, the nozzle assembly is removably coupled to the headgear. The nozzle assembly may be interchangeable with nozzle assemblies which do not include the exhaled breath component sensors, or nozzle assemblies with sensors capable of measuring different types of components of exhaled breath. Advantageously, removable components allows the collection chamber and or nozzle assembly to be removed for cleaning and maintenance. Additionally, in use a user can be provided with options for measurement of their exhaled breath.

Optionally, the sensor includes a protective cover. The protective cover may be used to protect the sensor during washing for example. In some examples the collection chamber may include filters, for example on inlets and or outlets. This may help to reduce contaminants such as dust, food particles, etc., from entering the collection chamber and interfering with measurements taken by the sensor.

Optionally, the sensor is configured to measure an amount of one or more Volatile Organic Compound (VOC) within the portion of exhaled breath. The VOC may be Ketone, Hydrogen, Methane, Carbon Dioxide, Oxygen, Ammonia, Acetone, Methanol, Ethanol, Isoprene, Acetonitrile, Hydrogencyanide, Formaldehyde, Amines, Organosulfur or any combination thereof.

Optionally the apparatus includes a processor coupled to the sensor and configured to analyse data measured by the sensor. The analysis may include comparison of the measurement data with a predetermined data set, such as standard readings or previously recorded data. Optionally, the apparatus includes a transmitter configured to transmit data measured by the sensor to an external device. In some examples, the processor may determine specific data to be sent to an external device via the transmitter, for example if a measurement is considered anomalous. Sending data to an external device may allow for that device to analyse the data and optionally present some or all of the data to user of the device. The external device may be capable of using the analysed data to make predications based on the measured component of the breath, for example the presence of formaldehyde could be indicative of a cancer in the wearer. So, the device may present an alert to the user of the device. Optionally, the apparatus includes a receiver, such that an external device can perform analysis of the measurements and return the analysed information to the apparatus.

Optionally, the apparatus includes an indicator configured to indicate based on the measured data or analysed data. In some examples, the processor may analyse the measured data and make a determination based on said data such as the measured data is above or below a predetermined threshold. The processor may then instruct the indicator to indicate based on that determination. Optionally the indicator includes an alarm configured to sound in response to the determination made by the processor.

Optionally, the indicator is an audio or visual indicator capable of providing a wearer or external viewer with information about the measurement of at least one component of the portion of exhaled breath. For example, the head wearable air purifier apparatus may include a display screen to show a value of the at least one component. In other examples, the head wearable air purifier apparatus may include a LED configured to light in response to the measured data or a speaker configured to read aloud the value of the measurement.

Optionally, the apparatus includes a control unit configured to control at least one of the processor, transmitter, indicator, and sensor. For example, upon determining a measurement from the sensor is above (or below) a threshold value the processor may send a signal to the controller. The controller may then instruct the transmitter to transmit data from the sensor to an external device and optionally the controller may instruct the indicator to indicate to a user information relating to the measurement.

Optionally, the apparatus includes a switch configured to turn on or off the sensor, such that the monitoring function of the apparatus is optional to the user. According to a second aspect of the invention there is provided a nozzle assembly for delivering purified air from an air purifier assembly of a head wearable air purifier apparatus to a wearer, the nozzle assembly comprising: a collection chamber for receiving at least a portion of exhaled breath; and a sensor configured to measure at least one component of the portion of exhaled breath; wherein the sensor is located in the collection chamber and the collection chamber comprises a one-way valve configured to selectively allow exhaled breath therethrough.. The nozzle apparatus may be a contained unit which includes the one-way valve(s) collection chamber, sensor, and some or all of the compatible features discussed herein. Advantageously, this may allow the nozzle assembly to be a retrofittable feature to pre-existing air purifier apparatuses, or replaceable if a component gets damaged.

According to a third aspect of the invention there is provided an electronic device configured to receive the measurement of at least one component of the portion of exhaled breath from the head wearable air purifier apparatus as described above.

Optionally, the electronic device is configured to analyse the measurement of at least one component of the portion of exhaled breath. In some examples, the electronic device may be configured to track or otherwise monitor the outputted data from the head wearable air purifier apparatus. The electronic device may be capable of making predictions based on the measurements and alerting a user to these predictions.

According to a fourth aspect of the invention there is provided a method of measuring at least one component of exhaled breath with a head wearable air purifier apparatus, the method comprising: selectively allowing at least a portion of an exhaled breath into a collection chamber of the head wearable air purifier apparatus via a one-way valve; and measuring at least one component of the portion of exhaled breath via a sensor in the collection chamber.

Optionally, the collection chamber includes a further one-way valve the further one-way valve positioned between the one-way valve and an outlet, and the method may include actuating the first and further one-way valves in response to an exhaled breath of a wearer such that the exhaled breath may be contained therebetween in the collection chamber.

Optionally, the method further includes transmitting data obtained by measuring at least one component of the portion of exhaled breath to an external device.

Optionally, the method further includes analysing the data obtained by measuring at least one component of the portion of exhaled breath.

Optionally, the method further includes reporting a value of the component of exhaled breath via in a wearer comprehendible format.

Optionally, the method further includes alerting via an alarm if the data obtained by measuring at least one component of the portion of exhaled breath exceeds or falls below a predetermined threshold value. It should be understood that unless specifically disclosed as incompatible the above features are considered combinable with one another.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Figure l is a schematic front view of a head wearable air purifier according to the present invention;

Figure 2 is a cross-sectional view of the head wearable air purifier of Figure 1 with a nozzle assembly removed;

Figure 3 is a schematic rear view of the nozzle assembly of the head wearable air purifier of Figure 1;

Figure 4a is a cross-sectional side view of a collection chamber according to an example of the present invention, with a one-way valve in an open position;

Figure 4b is a cross-sectional side view of the collection chamber according to Figure 4a, with the one-way valve in a closed position;

Figure 5a is a cross-sectional side view of a collection chamber according to a further example of the present invention, with a first and further one-way valve in an open position;

Figure 5b is a cross-sectional side view of a collection chamber according to Figure 5a, with a first and further one-way valve in an open position; and

Figures 6a to 6c illustrate representations of various electronics systems according to the present invention.

Throughout the description like numerals refer to like components.

Detailed Description

A head wearable air purifier, generally designated 10, is shown schematically in Figure 1. The head wearable air purifier comprises a headgear 12, first 14 and second 16 purifier assembly, and a nozzle assembly 100.

The headgear 12 has the form of a headband, is generally elongate and arcuate in form, and is configured to overlie a top of a head of a wearer, and sides of the head of the wearer, in use. The headgear 12 has a first end portion 18, a second end portion 20, and a central portion 22. Each of the first 18 and second 20 end portions are connected to the central portion 22 by an extension mechanism. Each extension mechanism, as shown in Figures 1 and 2, comprises an arm 24 that engages with teeth internal of the first 18 and second 20 end portions to form a ratchet mechanism that enables adjustment of the length of the headgear 12 by a wearer 15. To this end, the teeth, a spacing between the teeth and an opposing wall, or the arm 24 itself, may be sufficiently resilient to provide the required retention.

The first 18 and second 20 end portions of the headgear 12 each comprise a hollow housing 26. The hollow housing 26 defines a battery compartment for receiving one or more batteries therein. It will be appreciated that batteries may be removable from the hollow housing 26, or may be intended to be retained within the hollow housing 26 during normal use. Where the batteries are replaceable and intended to be removable from the hollow housing 26, the hollow housing 26 may, for example, comprise a releasable door or cover to enable access to the interior of the hollow housing 26. Where batteries are rechargeable and intended to be retained within the hollow housing 26 in normal use, the hollow housing 26, or indeed other components of the head wearable air purifier 10, may comprise at least one charge port to enable recharging of batteries.

The first 18 and second 20 end portions of the headgear 12 are connected to respective ones of the first 14 and second 16 purifier assemblies. In some examples, the first 18 and second 20 end portions of the headgear 12 are connected to respective ones of the first 14 and second 16 purifier assemblies such that relative movement is enabled between the first 18 and second 20 end portions of the headgear 12 and the respective first 14 and second 16 purifier assemblies. As shown in Figure 1, a swivel pin 28 is used for such a connection, but it will be appreciated by a person skilled in the art that other forms of connection are possible. To enable electrical connection of batteries contained within the hollow housings 26 of the first 18 and second 20 end portions of the headgear to components internal of the first 14 and second 16 purifier assemblies, the swivel pins 28 are hollow, for example to allow electrical wiring or the like to pass therethrough.

The first 14 and second 16 purifier assemblies comprise ear cups such as those typically used for so-called “over-the-ear” headphones, which are generally hemispherical and hollow in form.

Each purifier assembly 14,16 houses a speaker assembly 32, as shown in Figure 2, and comprises annular padding 34 configured to surround an ear of a wearer 15 of the head wearable air purifier 10. Details of the speaker assembly 32 are not pertinent to the present invention, and so will not be described here for the sake of brevity, but it will be recognised by a person skilled in the art that any appropriate speaker assembly may be chosen. In use, the speaker assemblies 32 received within the first 14 and second 16 purifier assemblies are configured to receive power from all of the batteries 36,38. Power transfer wiring (not shown) runs through the headgear 12 between the first 18 and second 20 end portions, for example through the central portion 22 and arms 24. Such an arrangement provides increased flexibility in power distribution between the speaker assemblies 32. In other embodiments the speaker assemblies 32 received within the first 14 and second 16 purifier assemblies may be configured to receive power from batteries 36,38 disposed in respective ones of the first 18 and second 20 end portions of the headband. For example, a speaker assembly 32 received within the first purifier assembly 14 may be configured to be powered by the batteries 36 within the first end portion 18 of the headgear 12, whilst a speaker assembly 32 received within the second purifier assembly 16 may be configured to be powered by batteries 38 within the second end portion 20 of the headgear 12. The first 14 and second 16 purifier assemblies of the head wearable air purifier 10 further comprise ambient air inlets 40, filter assemblies 42, and airflow generators 44.

The ambient air inlet 40 of each of the first 14 and second 16 purifier assemblies comprises a plurality of apertures through which air may be drawn into the interior of the purifier assembly 14,16. Each filter assembly 42 is disposed within a respective purifier assembly 14,16 between the ambient air inlet 40 and a respective airflow generator 44. Each filter assembly 42 comprises a filter material chosen to provide a desired degree of filtration of air to be provided to a wearer 15 in use.

The airflow generators 44 each comprise a motor driven impellers which draw air from the respective ambient air inlets 40, through the respective filter assemblies 42, and outputs air through one or more respective purified air outlet apertures 106, of the purifier assembly 14,16. The airflow generators 44 in the first 14 and second 16 purifier assemblies are configured to receive power from all of the batteries 36,38. Power transfer wiring (not shown) runs through the headgear 12 as described above in relation to the speaker assemblies 32. In other embodiments, the first purifier assembly may be configured to be powered by batteries 36 within the first end portion 18 of the headgear 12, whilst the airflow generator 44 in the second purifier assembly 16 may be configured to be powered by batteries 38 within the second end portion 20 of the head wearable air purifier 10. This may allow at least one airflow generator 44 to be operable in the event of failure of batteries 36,38 in one of the first 18 and second 20 end portions.

The nozzle assembly 100 is shown connected to the remainder of the head wearable air purifier 10 in Figure 1 and is shown in isolation from the remainder of the head wearable air purifier 10 in Figure 3. The nozzle assembly 100 is attached to the air purifier assemblies 14, 16 with releasable clips 46 such that the nozzle assembly is removable from the headgear 12 for maintenance and washing etc.

When the nozzle assembly 100 is connected to the first 14 and second 16 purifier assemblies, and the head wearable air purifier 10 is worn by a wearer, the nozzle assembly 100 is configured to extend in front of the face of the wearer, particularly the mouth and lower nasal region of the wearer, without contacting the face of the wearer 15 so as to provided purified air to the wearer 15. The head wearable air purifier 10 further includes an outlet 50, shown in Figure 1 on an exterior side face 52 of the nozzle assembly 100 to allow the exhaled breath the flow out from the head wearable air purifier 10. The present invention utilises this passage of exhaled breath through the headgear to measure components of the exhaled breath.

The nozzle assembly 100 is shown in Figure 3, with the wearer side face 102 illustrated. In use, the wearer side face 102 is the side of the nozzle assembly 100 which faces the wearer’s mouth and nasal region. The wearer side face 102 includes a purified air outlet 104 which delivers purified air from the air purifier assemblies 14, 16 to the wearer 15. Only one purified air outlet 104 is illustrated for simplicity and the air purifier outlet arrangement is not pertinent to the present invention, and so will not be described here for the sake of brevity, but it will be recognised by a person skilled in the art that any suitable arrangement may be used.

The wearer 15 inhales purified air via the nozzle assembly 100. The nozzle assembly 100 is generally arcuate in shape so as to follow the shape of a wearer’s face. As such, the wearer side face 102 is generally concave in shape. The wearer 15 exhales an exhaled breath predominantly forward of the mouth and toward the wearer side face 102 of the nozzle assembly 100. To capture a portion of the exhaled breath of the wearer, the wearer side face 102 of the nozzle assembly 100 includes an inlet 106 to a collection chamber, which is illustrated in Figures 4a and 4b and denoted 200, and Figures 5a and 5b and denoted 250. The inlet 106 is positioned so as to receive at least part of the exhaled breath of a wearer. The central portion 108 of the nozzle assembly 100 generally aligns with the wearer’s mouth and nose region in use. So, the inlet 106 is positioned in a central portion 108 of the nozzle assembly 100.

In this example, the purified air outlet 104 is in the same central portion 108 of the nozzle assembly 100 as the inlet 106. The inlet 106 is positioned spaced apart from the purified air outlet 104 within the central portion 108, which may help avoid crosscontamination of inhalable purified air and exhaled breath. Since the primary function of the nozzle assembly 100 is to provide the purified air flow to the wearer, the inlet 106 is less centrally positioned than the outlet 104 relative to the user’s mouth and nose region. In this way, delivery of the purified air to the wearer 15 may not be compromised.

In use, the exhaled breath passes through the inlet 106 and towards a collection chamber 200, 250 illustrated in Figures 4a to 5b, where a flow direction of the wearer’s breath is illustrated by arrow 210. The flow direction 210 is a direction away from the wearer’s mouth. Compared with an inhale breath which draws air from all directions around a mouth, an exhale breath has a more concentrated direction substantially forward of the user’s nose and mouth. The inlet 106 position is therefore optimized to receive the exhale breath.

Referring now to Figures 4a and 4b, the collection chamber 200 is formed within the nozzle assembly 100, for example via interior walls 202 of the nozzle assembly 100. The collection chamber 200 includes a one-way valve 204, which is illustrated in an open position in Figure 4a and a closed position in Figure 4b. The inlet 106 and oneway valve 204 can be an integral component or two separate components. In some examples where the inlet 106 and one-way valve 204 are a single component, the oneway valve 204 is flush with the wearer side face 102 of the nozzle assembly 100 when in the closed position.

The one-way valve 204 selectively allows exhaled breath to pass through the collection chamber 200. The selectivity of exhaled breath is achieved by using the force of an exhaled breath to actuate the one-way valve 204. Ambient air or purified air (particularly when actively directed toward a wearer’s mouth) does not provide a sufficient force to actuate the one-way valve 204. When the wearer 15 exhales, the exhaled breath exerts a push force onto the one-way valve 204 which causes it to move from the closed position shown in Figure 4b to the open position shown in Figure 4a. A typical exhale breath provides a force in the range of lOkPa to lOOOkPa, accordingly the one-way valve 204 is configured to actuate by a pressure in the range of lOkPa to lOOOkPa.

The one-way valve 204 is limited to opening in a singular direction such that the flow therethrough is limited to one direction. That is, the one-way valve 204 opens in the flow direction 210 of the wearer’s exhaled breath. In this example, the one-way valve 204 is a flap-valve having a hinge (not shown), or other pivot means which is limited actuating in the single direction. Although the one-way valve 204 is illustrated in the figures as hinged at one end, the one-way valve 204 could also be a circular flap valve which is hinged at the middle.

The one-way valve is formed of a resilient material, and biases the valve toward the closed position of Figure 4b. The force of the exhaled breath is sufficient to overcome the bias of the one-way valve 204 so as to cause it to open.

Positioned within the collection chamber 200 and downstream of the one-way valve 204 is a sensor 208. The sensor 208 extends at least part way into the collection chamber 200 from the wall 202 to which it is affixed. For example, the sensor 208 is positioned centrally relative to the collection chamber walls 202. This may optimize the exhaled breath flow over the sensor 208 to give more accurate readings. The sensor 208 is capable of measuring information relating to the exhaled breath of the wearer, such as the amount of one or more volatile organic compounds (VOCs) present in the exhaled breath. VOCs which can be found in exhaled breath include Ketone, Hydrogen, Methane, Carbon Dioxide, Oxygen, Ammonia, Acetone, Methanol, Ethanol, Isoprene, Acetonitrile, Hydrogencyanide, Formaldehyde, Amines, Organosulfur. The sensor 208 is therefore tuned to measure the amount of one or more of the VOCs present in the exhaled breath. Example sensors include Sensiron SGP40 and Sensiron SHTC3.

The sensor 208 is configured to take measurements continually. The sensor 208 has a slower reset time than the human breathing rate; Humans breathe at approximately 12-20 breaths per minute, i.e., 3-6 seconds per breath cycle and the sensor 208 has a reset time between 3 seconds and 12 seconds. So, the sensor 208 takes a rolling average measurement over a number of breaths.

The closing of the one-way valve 204 occurs with the inhale breath of the wearer 15. The loss of force from the exhaled breath, allows the one-way valve 204to close due to its resilient nature. When the one-way valve 204 is in the closed position the exhaled breath is contained within the collection chamber 200 for measurement via the sensor 208. In the closed position, the one-way valve 204 forms a barrier to prevent inflow of ambient air into the collection chamber 200 when there is no exhaled breath present.

A subsequent exhale breath of the wearer 15 repeats the cycle by re-opening the one-way valve 204 and driving the initial exhaled breath out of the collection chamber 200 through the outlet 50. In this way, the exhaled breath is expelled from the head wearable apparatus 10 once measured. In the Example shown by Figures 4a and 4b the outlet 50 is spaced apart from the sensor 208. The distance between the outlet 50 and sensor 208 is sufficient that any ambient air that ingresses through the outlet 50 does not reach the sensor 208 and influence the measurements. The distance between the sensor 208 and the outlet 50 between 20mm and 100mm.

The subsequent exhaled breath replaces the exhaled breath already in the collection chamber 200. Resultingly, the collection chamber 200 is almost exclusively filled with exhaled breath during use. The sensor 208 is therefore continuously measuring exhaled breaths and collecting the associated data. In addition to the distance between the outlet 50 and the sensor 208 this oneway flow of exhaled air through the collection chamber 200 may also help prevent ambient air reaching the sensor 208. In so much as the flow of air through the collection chamber 200 is one-way so any flow in the opposite direction would meet a resistance.

Figure 5a and 5b show an alternative example in which a collection chamber 250 incorporates a further one-way valve 214. Features already described with reference to Figures 4a and 4b will not be described again for brevity.

The further one-way valve 214 works in the same way as the one-way valve 204 (hereafter first one-way valve 204 for ease of reference). The further one-way valve 214 selectively allows exhaled breath to pass through the collection chamber 200. The selectivity of exhaled breath is achieved by using the force of an exhaled breath to actuate the further one-way valve 214. When the wearer 15 exhales, the exhaled breath exerts a push force onto the further one-way valve 214 which causes it to move from the closed position shown in Figure 5b to the open position shown in Figure 5a. The further one-way valve 214 is actuated through the pressure of the exhaled breath and returned to a closed position during the inhaled breath via the resilience of the further one-way valve 214.

The further one-way valve 214 is positioned downstream of the first one-way valve 204. In this way, the exhaled breath passes through the first one-way valve 204 before the further one-way valve 214. To this end there may be a negligible time delay between the closure of the first one-way valve 204 and the further one-way valve 214.

When in the closed position, shown in Figure 5b, the first and further one-way valves 204, 214 define a sub-chamber 220 therebetween. The sub-chamber 220 is closed off from the remainder of the collection chamber 250by the first and further oneway valves 204, 214. The sensor 208 is positioned within the sub-chamber 220, so between the first and further one-way valves 204, 214.

The further one-way valve 214 may reduce the chance of ambient air reaching the sub chamber 220 within the collection chamber 250via the outlet 50. As such, the collection chamber 250 can be shorter than the single valve arrangement collection chamber 200, as there is less need to distance the sensor 208 and the outlet 50. The sensor 208 is therefore between 10mm and 80mm from the outlet. When the valves 204, 214 move into the closed position there may be some slight ingress of air therethrough in the opposite direction to the flow direction 210. Since the air within the sub chamber 220 and outside of chamber 220 beyond the flap valves, both 204 and 214, is almost exclusively exhaled breath, any ingress through either valve will mostly likely be exhaled air.

The measurement data collected by the sensor can be used in multiple ways, Figures 6a to 6c show various arrangements for processing or analysing the data. To achieve this the head wearable air purifier 10 includes a controller 300. Referring to Figure 6a an example in which the controller 300 includes a processor 302 is illustrated. The controller 300 instructs the sensor 208 to provide the measurement data obtained to the processor 302. The processor 302 then analyses that data. For example, the processor 302 compares the data provided by the sensor against a saved standard data set. To this end, the processor has a memory which stores the standard data set. The processor 302 can thus determine if the measurement data differs significantly to the standard data set.

In the event of a significant difference with the standard data set is determined by the processor 302 the controller instructs the indicator 304 to indicate and thus inform the wearer 15 the significant difference has occurred. The indicator 304 is part of the speaker assembly 32 shown in Figure 2. The indicator 304 performs a read out of a warning to the wearer 15 via the speaker assembly 32.

Figure 6b illustrates an example in which the head wearable apparatus transmits the analysed data to an external device 308, such as a smartphone. In this example, the processor 302 analyses the data and passes that analysed data to a transmitter 306 under control of the controller 300. The transmitter 306 sends the analysed data to the external device 308. The skilled person will understand the transmission may be via any known means, for example Bluetooth. The external device 308 can then store and monitor the data received, for example with health monitoring applications.

Further, the wearer 15 can access the processed data via the external device. In some cases, the external device may alert the wearer 15 via a notification if the processed data is considered anomalous or indicative of a heath condition.

Figure 6c illustrates an example in which the raw data is transmitted directly to the external device 308. In this instance, the controller 300 does not require a processor. The controller 300 simply instructs the sensor 208 to pass the data directly to the transmitter 306. The transmitter 306 sends the obtained measurement data to the external device 308. The external device 308 performs analysis on the obtained measurement data. In the event the external device 308 detects an anomaly or health condition the external device 308 returns that information to a receiver 310 in the controller 300 linked to the indicator 304. As in Figure 6a, the indicator 304 can then perform a read out or warning via the speaker assembly 32 to the wearer 15.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. The invention has been described above as particularly useful for monitoring VOCs in breath. However, other characteristics of an exhaled breath are also envisaged as being measured, for example a temperature, pressure, speed of an exhale breath or a time between subsequent breaths.

In some cases, the first one-way valve may be set back from the inlet and by extension the wearer side face of the nozzle assembly. This may provide a degree of protection to the one-way valve. The nozzle assembly may also include multiple inlets spaced about the central region of the nozzle assembly, these multiple inlets could fluidically couple together to form the collection chamber. Alternatively, a nozzle assembly may have a plurality of collection chambers with associated sensors (which may be the same of different sensor types).

Although described as requiring a resilient member to close the valve(s) above, in some examples the inhale breath of the wearer may additionally or alternatively draw the one-way valve(s) closed by exerting a pull force on the one-way valve (s). This pull force from the inhale breath may be prevented from reopening the one-way valve in the opposite direction through a stopping means (not shown) such as lip or flange. Over drawing of the one-way valve(s) could allow ingress of ambient air and disrupt measurements. The stopping means therefore may help reduce ambient air ingress to the collection chamber.

Although described above as part of the nozzle assembly, the collection chamber may be a distinct chamber which is insertable in or on the nozzle assembly or headgear, for example contained within one or both the first and second air purifier assemblies. The collection chambers could therefore be interchangeable, through snap fittings and the like, such that the wearer 15 can alternate measurement type.

Although illustrated by the Figures as generally rectangular in shape the skilled person will understand that the collection chamber is generally considered a space for collecting the exhaled breath and can therefore be any shape capable of allowing flow therethrough. In some examples the collection chamber may have a tortuous path between the inlet and outlet, so as to fit around various other components present within the head wearable apparatus for example.

The collection chamber may include filters or membranes to remove dust or food particles, which may protect the sensor. The sensor itself may have a filter or membrane covering for protection.

Instead of comparing measured data with a standard data set, the processor may have a range of predetermined values and determine if the measured data falls within those predetermined values. The processor may store the data and then upon retrieval or transmission of the data, for example via Bluetooth ® with an application on a smartphone, graphically or numerically show the data over time. The processor may alternatively store the data and calculate total exhaled VOC Store the data so as to build up a selection of data first and have a threshold number of data points which triggers an alert.

It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.