Wearable thermoregulation device

Abstract

There is provided a wearable thermoregulation device 10 configured to be worn on a body of a user. The wearable thermoregulation device 10 comprises: a first housing 100 and a second housing 110, the

Description

Field of Invention The present invention relates to wearable thermoregulation devices and more specifically, wearable devices that provide active cooling. Background Hot flushes can manifest in people for a variety of reasons including general physical exercise. Hot flushes are characterised by a sudden feeling of warmth often to an uncomfortable level and is usually most intense over the face, neck, and chest leading to profuse sweating. A known solution to manage hot flushes is to place a cool object on a thermally sensitive body part such as the inside of the wrist, which sends a signal to the hypothalamus (the brains temperature control centre) to stop or reduce the hot flush. There are some devices that can be worn by a user that act to cool the skin of the user and achieve a similar goal. However, such devices either have too cumbersome a design or cannot provide enough cooling power. There is therefore a need for an improved device to manage hot flushes. Statements of Invention According to a first aspect of the present invention, there is provided a wearable thermoregulation device configured to be worn on the body of a user. The device comprises: a first housing and a second housing, the first housing comprising a first face; a thermal module locatable within the first housing; a controller and a power source locatable within the second housing; and a flexible wiring connecting the first housing and second housing; wherein the power source is configured to supply electrical power to the thermal module via the flexible wiring, the controller is configured to send a signal to the thermal module via the flexible wiring, and thereby cause the thermal module to change the temperature of the first face. The flexible wiring may be a flexible Printed Circuit Board (hereinafter flexible PCB) or any flexible electrical connection such as standard wiring. The change in temperature may be a decrease in temperature, i.e., causing the first face to cool down. In some embodiments, thermal module is further configured to heat the first face. The power source may be a battery such as a rechargeable battery. The second housing may further comprise a charging port for charging the battery or may be configured to allow inductive charging. Advantageously, having a first and second housing allows the device to have a sleeker design. Furthermore, use of flexible wiring allows the thermal module to be located in a different housing from the power source, thereby allowing for more cooling due to not having to compensate for heat dissipated from the power source and / or controller. The first housing may further comprise a second face located opposite the first face and at least one air vent located between the first face and the second face. The second face may have at least one air inlet. Located between the first and second face may be defined as the air vent being disposed between planes defined by the first face and second face, e.g. on a side of the housing. The at least one air vent may be located on a sidewall that spans between the first face and the second face. The at least one air vent may be two air vents located on substantially diametrically opposite sidewalls. The air vents may be configured to allow air to exit the first housing. The air inlet may be configured to allow air to ingress the first housing. The second face may, in use, be facing away from the body of the user. Advantageously, providing an entry point and exit point for air promotes efficient air flow within the first housing, enabling heat to be removed from the housing, thereby aiding the thermal module in providing a cooling effect. The thermal module may comprise a thermoelectric cooler having a heating surface and a cooling surface. The thermal module may comprise an active heat sink attached to the heating surface configured to remove thermal energy from the heating surface. The active heat sink may comprise a heat sink body having a plurality of fins for directing an air flow and a fan locatable proximal to the heat sink body for driving the air flow. The cooling surface may be configured to decrease the temperature of the first face of the first housing. The thermoelectric cooler may be a Peltier module having the heating surface on one side and the cooling surface on the other. The heat sink body may comprise a cut-out substantially in the middle thereof to house the fan. In other embodiments, the cut-out may be provided off-centre within the heat sink body. In alternative embodiments, the fan may be provided on top of the fins at a distal end to the heating surface. In some embodiments, the fins are substantially straight and parallel to each other. In alternative embodiments, the fins may be longitudinal ribs. The longitudinal ribs may be curved to improve the aerodynamics. In some embodiments, the fins may be pins. Advantageously, the active heat sink provides improved heat rejection by allowing the active heat sink to extract heat from the heating surface of the thermoelectric cooler. Further advantageously, the thermoelectric cooler may provide active cooling that may lower the temperature of the user’s skin by between 10-15 degrees Celsius, when the first face is mounted against the skin. This provides an advantage over prior art devices which may only provide a cooling of 2-4 degrees Celsius. When the fan is located within a cut-out, this may provide the advantage that the first housing to be smaller and more aesthetic when worn by the user. It has been realised by the inventors that this range of cooling provides a sufficiently powerful temperature reduction to manage hot flushes whilst not being too cool as to be painful for the user. Skin temperature, or temperature of the user’s skin, may denote the mean temperature of the user’s skin measured by a sensor disposed between the first face of the device and the user’s skin when the first face is mounted against the user’s skin. The fan may be configured to pull air into the first housing through the at least one air inlet and expel air out of the first housing through the at least one air vent. In some alternative embodiments, the fan is configured to pull air into the first housing through the at least one air vent and expel air out of the first housing through the at least one air inlet. Advantageously, the fan can convert the single direction air inlet flow into at least one air exhaust flow paths through the heat sink for the warm air to exit the first housing. The first housing may further comprise a roof located on top of the plurality of ribs of the heat sink thereby partially enclosing the plurality of channels. Advantageously, partially enclosing the plurality of channels, prevents air passing therethrough from getting pulled back into the air inlet stream, and / or or ensures the air exits the first housing. The controller may be configured to send a signal to the thermal module via the flexible wiring thereby causing the thermal module to periodically activate and deactivate for a predetermined period of time. The thermal module may activate when the thermal module is actively providing a cooling effect, i.e., the thermoelectric cooler is active and the fan is promoting air flow through the first housing and the thermal module is drawing power from the power source. In some embodiments, the thermoelectric cooler may be active, but the fan is not active. The thermal module may be deactivated when it is not active. In some embodiments, the thermal module is activated for approximately 5 seconds and deactivated for approximately 15 seconds periodically for approximately 8 hours. In some embodiments, the thermal module may be activated for approximately 10 seconds, 15 seconds, 20 seconds, or 25 seconds. In some embodiments, the thermal module may be deactivated for approximately 5 seconds, 10 seconds, 20 seconds, or 25 seconds. In general, the skilled person will recognise that any combination of activation time and deactivation time may be suitable. Advantageously, having periodic cycles of active cooling creates a cyclic cooling effect (also known as the thermal alliesthesia effect) which may prevent a hot flush from occurring or reduce the severity of a hot flush or shorten it. Additionally, this reduces the amount of power needed by the thermal module by limiting how long the thermal module is activated, thereby allowing the device to operate for extended periods of time (such as all night). The thermal module may be configured to operate at a plurality of distinct power levels. Operating at a specific power level may mean it draws a specific amount of power from the power source. Operating at a specific power level may mean the thermal module provides a fixed amount of cooling. Operating at a higher power level may mean providing more cooling. Advantageously, operating different power levels allows the user to customise how much cooling they receive depending on the severity of their hot flushes. The first housing and second housing may be mounted to a strap configured to be worn around a user’s wrist. The flexible wiring may be located within a portion of the strap. In some embodiments, said portion of the strap may be formed of silicone. The flexible wiring may be over-moulded with silicone. The strap may comprise silicone lugs configured to be housed within the first and / or second housing thereby mounting the housings to the strap. Advantageously, providing a portion of the strap in silicone allows for greater durability of the device. Providing silicone lugs that can be housed within the housings allows the device to be easily assembled and disassembled by having the housings open and close with screws and no requirement for glue. The strap may comprise a plurality of perforations configured to at least partially align with the at least one air inlet of the second face. The plurality of perforations may be in a portion of the strap formed of fabric. Alternatively, the plurality of perforations may be in a portion of the strap formed of silicone. The strap may comprise a first strap portion formed of silicone for housing the flexible wiring and a second strap portion formed of fabric for circumnavigating the body portion of the user when the device is in use. The second strap portion may hold the first and second housing against the user when in use. Having a plurality of perforations in the strap allows the strap to act as a filter to block some objects (e.g., objects above 2.5mm and / or dirt, alternatively, objects above 2mm, 1.5mm, or 1mm) from entering the device and damaging the thermal module. The skilled person will recognise that the plurality of perforations may be configured to filter objects of any desired size. The device may further comprise at least one sensor in electric communication with the controller. The at least one sensor may be at least one of: a humidity sensor, a heart rate sensor, an SpO2 sensor, an accelerometer, a skin conductivity sensor, an ambient temperature sensor, and / or a GPS sensor. The controller may receive humidity data from the humidity sensor. The controller may be configured to detect a hot flush by detecting an increase in humidity over a predetermined threshold. The controller may receive data from the at least one sensor. The controller may be further configured to detect a hot flush based on the received data. In some embodiments, the humidity sensor may be located on the second housing. In alternative embodiments, the humidity sensor may be located on the strap. In some embodiments, the humidity sensor may comprise a heater for releasing humidity into the ambient air. In some embodiments, the device may further comprise at least one of: heart rate sensor, SpO2 sensor, accelerometer, skin conductivity sensor, ambient temperature sensor, and / or GPS sensor. The further sensors may cooperate with the humidity sensor to detect a hot flush, may be used in isolation to detect a hot flush, or may cooperate with any subset of the above sensors to detect a hot flush. Advantageously, the humidity sensor is able to detect the onset of perspiration that can be interpreted to be the beginning of a hot flush. It has been realised that humidity sensors are faster at detecting the onset of a hot flush compared to thermal sensors. When the controller detects a hot flush, the controller may send a signal to the thermal module via the flexible wiring, and thereby cause the first face to change temperature. Advantageously, this provides an automatic detection of the onset of hot flushes and can provide relief before extreme discomfort is beset onto the user. The device may further comprise a wireless transmitter configured to communicate with an application on a user device. In some embodiments, the wireless transmitter may be a Bluetooth® transmitter. In some embodiments, the wireless transmitter may be configured to send and / or receive information between the controller and the application on the user device. The user may use the application to send a signal to the controller to activate and / or deactivate the thermal module. Alternatively, the application may automatically send a signal to the controller to activate and / or deactivate the thermal module. The user may use the application to see metadata from the controller, for example (but not limited to) charge remaining, how many times the thermal module activated, how long the thermal module was activated for, and any other data to which the controller has access. Advantageously, this allows the device to communicate with an application on a user device allowing the application to control the wearable thermoregulation device from the user device. The second housing may further comprise a display screen. In some embodiments, the display screen may be a graphical user interface (GUI). Advantageously, the display screen may display useful information, such as the time or power remaining in the power source of the device. Brief Description of Figures The invention will now be described, by way of reference only, with respect to the accompanying Figures, in which: Figure 1 shows an exploded view of a wearable thermoregulation device in accordance with the present invention; Figure 2 shows an exploded view of the first housing of the wearable thermoregulation device of Figure 1; Figure 3 shows a schematic cross section of the first housing of Figure 2, in use; Figure 4 shows a perspective view of the device of Figure 1; and Figure 5 shows graphs of cooling regimes exhibited by the device of Figure 1, in use. It should be noted that the Figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these Figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings. The same reference signs are generally used to refer to corresponding or similar features in modified and different embodiments. Detailed Description Turning to Figure 1, there is shown an exploded view of a wearable thermoregulation device in accordance with the present invention. Figure 1 shows a wearable thermoregulation device 10 (hereinafter device 10). The device 10 comprises a first housing 100 and a second housing 110. The first and second housings 100, 110 are each formed by two plastic shells 100a, 100b and 110a, 110b respectively which can be fixed together using screws (not shown), adhesive, or any appropriate fixing means to form the housings 100, 110. The plastic shell 100a has a void 102a for receiving a first face (not shown). Plastic shell 100b has an air inlet 102b that allows air into the first housing 100 but restricts larger particles from entering which could cause damage to the internal components. Plastic shells 100a and 100b together provide two inlets each so that when they are fixed together, they can house air vents 304 (shown in Figures 3 and 4). The first housing 100 is configured to contain a thermal module 104. The thermal module 104 is configured to cool down the first face. In use, the first face abuts an anterior portion of a user’s wrist. The thermal module 104 will be described in greater detail below. The second housing 110 is configured to contain a power source 112. In the present embodiment, the power source 112 is a rechargeable battery. The second housing 110 is further configured to contain a controller 114. The controller 114 can send and receive signals to various other components of the device 10. The first and second housing 100, 110 are connected by a flexible wiring 120. The flexible wiring 120 can carry electrical power and electrical signals to the thermal module 104. The flexible wiring 120 is flexible and can be deformed by bending and twisting without damaging the ability to carry electrical power and signals. By supplying electrical power and electrical signals to the thermal module 104, the power source 112 can power the thermal module 104 without having to be located proximally to, and thereby heat, the thermal module 104. The controller 114 is configured to send a signal to the thermal module 104 via the flexible wiring 120. The signal causes the thermal module 104 to activate and cool the first face. A further signal can be sent to the thermal module 104 causing the thermal module 104 to deactivate (i.e. stop actively cooling the first face). The controller 114 can send a signal to the thermal module 104 when the user presses a button (not shown) on the second housing 110 or any other predetermined action such as receiving a signal from a user device (not shown). As will be described below, in some embodiments, the controller 114 sends a signal to the thermal module 104 upon detection of a hot flush. Turning to Figure 2, there is shown an exploded view of the first housing 100. In particular, the thermal module 104 is shown comprising a thermoelectric cooler 201. The thermoelectric cooler 201 uses the Peltier effect to create a heat flux across the thermoelectric cooler 201. This results in a cooling of a face of the first housing 100 in turn providing a cooling effect to the user. The thermoelectric cooler 201 comprises a cooling surface 202 and a heating surface 203 disposed on opposite ends of the thermoelectric cooler 201. The cooling surface 202 is the surface that, in use, is proximal to the user’s anterior wrist to provide a cooling effect. Opposite the cooling surface is the heating surface 203, i.e., is on the distal side of the thermoelectric cooler 201 when in use. In use, thermal energy is driven from the cooling surface 202 to the heating surface 203, thereby cooling the cooling surface 202. As the temperature differential between the cooling surface 202 and heating surface 203 grows, the thermal electric cooler 201 becomes less efficient. There is therefore a need to remove thermal energy from the heating surface 203. This is achieved by an active heat sink. The active heat sink comprises a heat sink body 204 and a fan 206. The heat sink body 204 has a plurality of fins 208 which form a plurality of channels along the heat sink body 204. The heat sink body 204 further has a cut-out 209 substantially in the middle of the heat sink body 204 to house the fan 206. The heat sink body 204 abuts the heating surface 203 and is thermally conductive. In use, the active heat sink removes the thermal energy built up on the heating surface 203 thereby further driving the cooling surface to cool. In some embodiments, the electrical current through the thermoelectric cooler can be reversed thereby causing the cooling surface to heat and the heating surface to cool. In such embodiments, the fan 206 is not necessarily activated but can sometimes be activated if heat soaks from the cooling surface (presently being heated) to the heating surface (presently being cooled) and creates a loop of inefficiency or thermal runaway. Turning to Figure 3, there is shown a schematic cross section of the first housing 100 in use. In use, the fan 206 rotates (as indicated by the circular arrow) in such a way that air is drawn into the first housing through the air inlet 102b along path I. The air is then driven through the plurality of channels formed by the plurality of fins 208. The air is then exhausted from the first housing 100 along paths Oi and O2 via the air vents 304. In the present embodiment, the first housing 100 further comprises a rigid PCB 302 fixed atop the heat sink body 204 thereby substantially enclosing the channels formed by the fins 208. This directs air out of the first housing 100 and prevents air that is flowing out of the first housing 100 along paths Oi and O2 from being pulled back up through and recycled directly back into the intake current along path I. Turning to Figure 4, there is shown a perspective view of the device 10. The first and second housings 100, 110 are connected to each other via straps 420, 430 thereby forming an annular ring configured to be worn on a user’s wrist. Strap 420 is formed by moulding silicone over the flexible wiring 120. Strap 430 has a releasable securement mechanism 435 configured to either lengthen the strap 430 to adjust it to fit the user’s wrist or to disconnect the strap from the second housing 110. In the present embodiment, the releasable securement mechanism 435 is a Velcro® strap having a loop portion and a hook portion emanating from the first housing 100 and a buckle emanating from the second housing 110. The Velcro® strap loops around the buckle and the hook portion aligns with the loop portion thereby securing the releasable securement mechanism 435. The skilled person will recognise that any appropriate releasable securement mechanism 435 could be used. The second housing 110 is further provided with a charging port 116 that is in electrical connection with the power source 112. The charging port 116 can be coupled with a charger (not shown) thereby (re-)charging the power source 112. The strap further comprises a perforated surface 402b which comprises a plurality of perforations configured to at least partially align with the air inlet 102b so as to not restrict air intake. The perforated surface 402b further provides a filter which restricts unwanted particles from entering the first housing 100. Turning to Figure 5, there is shown graphs of cooling regimes that are achievable by the device 10 in use. Graph 500 shows a skin temperature of the user wearing the device 10 over time. The device 10 in this example is set to “night mode” wherein the controller 114 instructs the thermal module 104 to periodically apply cooling for short bursts of time. In the present embodiment, the controller 114 instructs the thermal module 104 to activate (thereby cool the skin) for a period of 5 seconds and then to deactivate (no longer actively cool) for a period of 15 seconds and repeat this cycle for approximately 6 to 8h. The skilled person will understand that different time periods are equally envisaged, and the present embodiment is by way of example only. Graphs 510 and 512 show the skin temperature of the user wearing the device 10 over time. The user can send instructions to the controller 114 to cause it to, in turn, send instructions to the thermal module 104 to cool. The user may send instructions to the controller 114 by way of an application on their user device, by use of buttons or other sensors on the device 10, or any other suitable input method. The graphs 510 and 512 show a short burst of cooling (i.e. approximately 180 seconds, though the user may customise this time period). The user can further choose how powerful they want the cooling to be, a more powerful cooling results in a lower temperature achieved in graph 512 when compared to graph 510. The user can customise this either in an application on a user device or through the use of buttons on the device 10 or any other suitable input means. In exemplary cooling regimes 510 and 512, the first face of the thermal module cools down to between 16-18 degrees Celsius when it is mounted against the user’s skin i.e., it reduces the user’s skin temperature by approximately 10-15 degrees Celsius. Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The applicant hereby gives notice that new claims may be formulated to such features and / or combinations of such features during the prosecution of the present application or of any further application derived therefrom. Skin temperature, in this embodiment, denotes the mean temperature of the user’s skin as measured by a sensor (not shown) disposed between the first face of the device 10 and the user’s skin when the first face is mounted against the user’s skin. 5 For the sake of completeness, it is also stated that the term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality, a single processor or other unit may fulfil the functions of several means recited in the claims and reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

1. A wearable thermoregulation device configured to be worn on a body of a user, comprising:5 a first housing and a second housing, the first housing comprising:a first face;a second face opposite the first face, the second face having at least one air inlet; andat least one air vent located between the first face and the second face;10 a thermal module locatable within the first housing, the thermal modulecomprising:a thermoelectric cooler having a heating surface and a cooling surface; andan active heat sink attached to the heating surface configured to remove15 thermal energy from the heating surface, the active heat sink comprises:a heat sink body having a plurality of fins for directing an air flow, comprising a cut-out substantially in the middle of the heat sink body; anda fan locatable within the cut-out of the heat sink body for driving the air flow,20 wherein the cooling surface is configured to decrease the temperature ofthe first face of the first housing;a controller and a power source locatable within the second housing; and a flexible wiring connecting the first housing and second housing;wherein the power source is configured to supply electrical power to the thermal 25 module via the flexible wiring,the controller is configured to send a signal to the thermal module via the flexible wiring, and thereby cause the thermal module to change the temperature of the first face.30 2. The device of claim 1, wherein the change in temperature is an increase and / ora decrease in temperature.

3. The device of claim 1 or claim 2, wherein the fan is configured to pull air into the first housing through the at least one air inlet and expel air out of the first housing 35 through the at least one air vent.12 12254. The device of any of claims 1 to 3, wherein the first housing further comprises a roof located on top of the plurality of thermal fins of the heat sink body thereby partially enclosing a volume between the heating surface and the roof.

55. The device of any preceding claim, wherein the controller is configured to send a signal to the thermal module via the flexible wiring thereby causing the thermal module to periodically activate and deactivate for a predetermined period of time.10 6. The device of any preceding claim, wherein the thermal module is configured tooperate at a plurality of distinct power levels.

7. The device of any preceding claim, wherein the first housing and second housing are mounted to a strap configured to be worn around a user’s wrist, wherein the flexible 15 wiring is locatable within a portion of the strap.

8. The device of claim 7. wherein the strap comprises a plurality of perforations configured to at least partially align with the at least one air inlet of the second face.20 9. The device of any preceding claim further comprising at least one sensor inelectric communication with the controller, wherein the at least one sensor is one of: a humidity sensor, a heart rate sensor, an SpO2 sensor, an accelerometer, a skin conductivity sensor, an ambient temperature sensor, and / or a GPS sensor.25 10. The device of claim 9, wherein the controller receives data from the at least onesensor and is further configured to detect a hot flush based on the received data.

11. The device of claim 10, wherein, upon detection of a hot flush, the controller is configured to send a signal to the thermal module via the flexible wiring, and thereby 30 cause the first face to change temperature.

12. The device of any preceding claim further comprising a wireless transmitter configured to communicate with an application on a user device.

13. The device of any preceding claim, wherein the second housing further comprises a display screen.12 1225

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