WO2019117966A1

WO2019117966A1 - Noninvasive blood monitoring ear bud

Info

Publication number: WO2019117966A1
Application number: PCT/US2017/066852
Authority: WO
Inventors: Viktor Shkolnikov; Rafael Ballagas; Sarthak GHOSH
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2017-12-15
Filing date: 2017-12-15
Publication date: 2019-06-20

Abstract

A noninvasive blood monitoring earbud may include a chamber sized for insertion into an ear canal, wherein the chamber is formed by an outer wall and at least a portion of the outer wall is flexible. Earbud may further include a pressure adjuster, an optical emitter and an optical detector. The pressure adjuster is to exert an adjustable pressure against a surface of the ear canal. The optical emitter is to direct light through the outer wall. The optical detector is to output signals in response to receiving the light reflected from the surface of the ear canal through the outer wall.

Description

NONINVASIVE BLOOD MONITORING EAR BUD

BACKGROUND

[0001] Blood is often sensed or monitored to identify a condition or health of a person or animal. For example, blood flow or pulse may be sensed as an indicator of a person’s or animal’s health. The content of the blood may be also sensed to identify health conditions for the person or animal. Oxygen content or saturation of the blood may indicate a life-threatening situation. Blood glucose concentrations or levels may also indicate health concerns. For example, blood sugar concentrations or abnormal levels of blood glucose may lead to severe health conditions. Hyperglycemia (high blood sugar) may lead to heart disease, eye, kidney and nerve damage. Hypoglycemia (low blood sugar) may cause lethargy, impaired mental functioning, irritability, twitching, shaking, weakness, pale complexion, sweating, loss of consciousness and even death. Glucose monitoring facilitates better control and management of blood sugar concentrations.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Figure 1 is a schematic diagram illustrating portions of an example noninvasive blood monitoring earbud.

[0003] Figure 2 is a sectional view schematically illustrating an example chamber of the earbud of Figure 1 in a smaller state and in an enlarged state.

[0004] Figure 3 is a sectional view illustrating portions of an example chamber of the earbud of Figure 1 , illustrating portions of an example outer wall in various example pressure applying states. [0005] Figure 4 is a sectional view illustrating portions of an example chamber of the earbud of Figure 1 , illustrating portions of an example outer wall in different pressure applying states.

[0006] Figure 5 is a schematic diagram illustrating portions of an example noninvasive blood monitoring system.

[0007] Figure 6 is a diagram illustrating various example states for an example outer wall of an example chamber of the example earbud of Figure 5.

[0008] Figure 7 is a diagram illustrating portions of an example noninvasive blood monitoring system.

[0009] Figure 8 is a flow diagram of an example method for monitoring a glucose level.

[00010] Figure 9 is a flow diagram of an example method for monitoring a glucose level.

[00011] Figure 10 is a schematic diagram illustrating portions of an example noninvasive blood monitoring system.

[00012] Figure 1 1 is a sectional view illustrating an example earbud of an example noninvasive blood monitoring system position within an example ear canal.

[00013] Figure 12 is a sectional view schematically illustrating the example noninvasive blood monitoring system of Figure 1 1.

[00014] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION OF EXAMPLES

[00015] Disclosed herein are example blood monitoring earbuds, blood monitoring systems and methods that facilitate noninvasive monitoring of blood, such as its content or flow. In one implementation, the blood monitoring earbuds facilitate the monitoring of glucose levels. The example glucose monitoring earbuds output signals that indicate a degree to which light directed at tissue or blood vessels is absorbed/reflected. The degree to which light directed the tissue is absorbed/reflected may indicate glucose levels within the tissue or blood vessel. The disclosed monitoring earbuds glucose monitoring systems and methods that facilitate glucose level monitoring without skin piercing or pricking, reducing risk of infection. By eliminating skin piercing or pricking, the example glucose monitoring earbuds, systems and methods reduce discomfort, facilitating more frequent glucose monitoring and better patient compliance with glucose monitoring regimens.

[00016] Disclosed herein are example blood monitoring earbuds, systems and methods that facilitate the noninvasive monitoring of blood without the complexities that often exist in current noninvasive blood monitoring devices. The example blood monitoring earbuds, systems and methods utilize a chamber that is inserted into an ear canal, wherein a pressure adjuster exerts an adjustable and reproducible pressure against a surface of the ear canal to displace tissue of the ear canal extending over subcutaneous blood vessels. Displacement of the tissue facilitates enhanced sensing of blood content or blood flow.

[00017] In one implementation, the blood monitoring earbuds direct light towards the subcutaneous blood vessels, wherein absorption (and reflection) of light directed at the tissue and subcutaneous blood vessels is detected and wherein the extent of light absorption/reflection may indicate blood flow or content, such as level of glucose in the tissue or blood vessel. The pressure adjuster further assists in retaining the earbud within the ear canal.

[00018] In some implementations, the chamber is inflatable, wherein the pressure adjuster may comprise a pump to inflate the chamber to various inflation states at which different pressures may be selectively applied against the surface of the ear canal. In some implementations, a controller may actuate the pressure adjuster, whether a fluid pump or some other form a pressure adjuster, between different states. For example, in one

implementation, the controller may actuate the pressure adjuster between a first monitoring state pressure level for monitoring glucose levels and a second non-monitoring state pressure level less than the first monitoring pressure level. The second non-monitoring state pressure level may be a level of pressure that is more comfortable or less noticeable to person or animal wearing the earbud. In one implementation, the controller may actuate the pressure adjuster between a first monitoring state pressure level for monitoring glucose levels, a second non-monitoring state pressure level less than the first monitoring pressure level for retaining the earbud within the ear canal and a third withdrawing pressure level less than the second non monitoring state pressure level, facilitating withdrawal of the earbud from the ear canal.

[00019] In some implementations, the controller may actuate the pressure adjuster between different pressure level states based upon or in response to signals received from a sensor that senses motion of the earbud. For example, a monitoring protocol may call for glucose monitoring when the person or animal wearing the earbud is active or at rest as well as when the person or animal wearing the earbud is active or exercising. Signals from a sensor, such as from at least one accelerometer or a gyroscope, may indicate the level of activity of the person or animal, wherein signals from the sensor may be used to trigger the initiation of blood monitoring and/or terminate ongoing blood monitoring. In some implementations, different blood characteristics occurring during the use of the earbud may be recorded along with their associated levels of activity as detected by the sensor. In some implementations, the controller may adjust the pressure adjuster between multiple different non-monitoring monitoring pressure level states depending upon or in response to signals from a sensor indicating the activity level of the person or animal. For example, the controller may actuate the pressure adjuster to a higher pressure level or state when the person is active, such as when the person is running, to better assist in maintaining the earbud within the person’s ear canal.

[00020] In some implementations, the controller may actuate the pressure adjuster between different pressure level states based upon inputs from a person. For example, actuation of a switch, button, slide or other input mechanism may cause a controller to adjust the pressure actuator to different pressure applying states, such as a pressure applying states described above. In one implementation, the input may provide on the earbud itself. In other implementations, the earbud may comprise a transceiver which receives input commands from an external device, such as from a remote smart phone, player or other device.

[00021] The example earbuds and methods have an optical emitter that directs light through an outer wall of the inflatable chamber and an optical detector that outputs signals in response to receiving the light reflected from the surface of the tissue of the ear canal through the outer wall. Because light is transmitted through the outer wall of the inflatable chamber, the optical emitter and the optical detector may be located out of contact with the ear canal tissue, providing enhanced comfort and reducing the potential for damage to the emitter and detector.

[00022] Disclosed herein are example blood monitoring earbuds and methods that utilize a reflective surface between the optical emitter and the opposite detector such that light from the optical emitter is repeatedly reflected off of the reflective surface and multiple distinct surfaces of the tissue of the ear canal prior to being sensed by the optical detector. In some implementations, the reflective surface is provided on an exterior of the inflatable chamber. In other implementations, the reflective surfaces provided on an interior of the inflatable chamber, such as on the services of an interior core. The multiple reflections off of the ear canal tissue may enhance blood monitoring performance by obtaining multiple measurements from multiple locations for determining flow of blood or blood content.

[00023] In some implementations, the example blood monitoring earbuds and methods are dual-purpose. For example, in some

implementations, the example blood monitoring earbuds and methods further comprise an audio speaker that may output audible sounds, such as music or speech. In one implementation, the earbud may comprise a controller, wherein the controller adjusts the pressure actuator to different pressure applying states depending upon signals indicating whether the audio speaker is in use or out of use.

[00024] Disclosed herein is an example noninvasive blood monitoring earbud that may include an inflatable chamber sized for insertion into an ear canal, the inflatable chamber formed by an outer wall, at least portions of which are flexible, a pump to inflate the inflatable chamber with a fluid, an optical emitter to direct light through the transparent flexible wall, an optical detector to output signals in response to receiving the light reflected from surfaces of the ear canal through the outer wall and a processing unit to determine and output a blood content or blood flow/pulse reading based upon the signals.

[00025] Disclosed herein is an example noninvasive blood monitoring earbud that may comprise an optical emitter to direct light at surfaces of an ear canal in which earbud is inserted, an optical detector, a reflective surface between the optical emitter and the optical detector such that the light from the optical emitter repeatedly reflects off the reflective surface and the surfaces of the ear canal prior to being sensed by the optical detector and a processing unit to determine a glucose level based upon signals from the optical detector.

[00026] Disclosed herein is an example method for noninvasively monitoring blood characteristics with an earbud position within an ear canal. The method may comprise adjusting a pressure level exerted by a chamber with a pressure adjuster. In one implementation, the chamber may be inflatable, wherein adjusting a pressure level comprises inflating the inflatable chamber of the earbud. The method may include light that has reflected off surfaces of the ear canal and passed through a wall of the inflatable chamber and determining the characteristics of blood, such as floor content, based upon sensed light.

[00027] Disclosed herein is an example method for noninvasively monitoring blood characteristics, such as content or flow, with an earbud, wherein the method may comprise inflating an inflatable chamber of an earbud within an ear canal to the first inflation state and sensing the first light that has reflected off surfaces of the ear canal and passed through wall of the inflatable chamber while the inflatable chambers in the first inflation state. The method may further comprise inflating the inflatable chamber of the earbud within the ear canal to a second inflation state different than the first inflation state based upon the sensed first light and sensing a second light that has reflected off surfaces of the ear canal and passed through the wall of the inflatable chamber while the inflatable chambers and the second inflation state. A glucose level may be determined based upon the sensed second light.

[00028] Figure 1 schematically illustrates portions of an example noninvasive blood monitoring earbud 20. Earbud 20 provides accurate and reliable noninvasive monitoring of blood content and/or blood flow. Earbud 20 comprises chamber 24, pressure adjuster 28, optical emitter 32 and optical detector 36. In the example illustrated, earbud 20 provides accurate and reliable noninvasive monitoring of glucose levels.

[00029] Chamber 24 comprises a body having an adjustable size, being selectively actuatable between different sizes that result in different levels of pressure or force being applied against adjacent tissue of an ear canal in which chamber 24 is positioned. In at least one selected size, chamber 24 is sized for insertion into an ear canal 43 (schematically illustrated). Chamber 24 has an outer wall 46, at least portions of which are flexible such that the outer dimensions of chamber 24 may be varied by pressure adjuster 28 so as to press against the surrounding tissue of ear canal 43 and apply a selected level of pressure against the tissue of ear canal 43. In one implementation, the flexible portion or portions of outer wall 46 has sufficient flexibility and/or stretchability such that the size of chamber 24 may be sufficiently enlarged to apply a sufficient amount of pressure to the external tissue of ear canal 43 so as to push aside portions of subcutaneous tissue for enhanced access to subcutaneous tissue and blood vessels.

[00030] In the example illustrated, the flexible portions of outer wall 46 form an entirety of the exterior of chamber 24, including axial ends of chamber 24. As a result, the entirety of chamber 24 changes size or shape. Figure 2 illustrates chamber 24 in two different pressure states: a smaller state (SS) and an enlarged state (ES) (shown in broken lines). In the enlarged state, chamber 24 exerts a greater amount of pressure against adjacent tissue of the ear canal 43. In one implementation, chamber 24 is actuated between the smaller state and the enlarged state through inflation and deflation of chamber 24 by pressure adjuster 28. In other implementations, chamber 24 may be actuated between the two states in other manners by pressure adjuster 28 [00031] Figure 3 illustrates portions of outer wall 46’ of another example chamber 24’of earbud 20 in various pressure states. In the example illustrated, outer wall 46’comprises rigid portions 50, light transmitting portion 52 and connecting portions 54. Rigid portions 50 are generally inflexible and rigid, having a greater rigidity as compared to connecting portions 54. In one implementation, rigid portions 54 may be formed from a polymer having a thicknesss so as to be non-bendable and non-stretchable.

[00032] Light transmitting portion 52 comprise a portion of outer wall 46” that is transparent such that light emitted from emitter 32 and pass through light transmitting portion 52, reflect off the adjacent tissue of ear canal 43 and passed once again through light transmitting portion 52 for detection by detector 36. In one implementation, light transmitting portion 52 is formed from a transparent inflexible, rigid material, such as a transparent rigid polymer. In another implementation, light transmitting portion 52 may additionally be formed from a flexible and/or resiliently stretchable transparent material. In some implementations, light transmitting portion 52 may comprise a transparent pane or window surrounded by an opaque rigid or flexible panel.

[00033] Connecting portions 52 comprise regions of outer wall 46 that are flexible/bendable and/or stretchable. Connecting portions 54 extend between light transmitting portion 52 and rigid portions 50 of outer wall 46’of chamber 24’. As shown by Figure 3, connecting portions 54 are resiliently stretchable, facilitating the repositioning of light transmitting portion 52 relative to rigid portions 50. Figure 3 illustrates chamber 24’ in four different pressure states in which chamber 24’ is differently sized such that different degrees of pressure are exerted against the adjacent tissue of ear canal 43. In pressure state PS1 , connecting portions 54 are in an un-stretched state such that chamber 24’ has a small size that may facilitate withdrawal or insertion of chamber 24 into the ear canal. In states PS2 and PS3, chamber 24’ is in a larger state, applying greater amount of pressure against the tissue of ear canal 43. In one implementation, pressure states PS2 and PS3 are non- monitoring pressure states, wherein chamber 24 is retained within the ear canal 43 but is not exerting a sufficient amount of pressure to provide glucose monitoring. In one implementation, pressure state PS2 may be a lower pressure state such as when the person is inactive and there is less potential for movement of chamber 24’within the ear canal 43. Pressure state PS3 may be a higher pressure state as compared to pressure state PS2, more reliably securing chamber 24’ against movement such as when the person is in an active state, such as running. Pressure state PS4 is a monitoring state pressure, greater than the amount of pressure exerted against the tissue of ear canal 43 when chamber 24’is in pressure states PS1-PS3. In the monitoring state pressure PS4, a sufficient amount of pressure exerted against the tissue of ear canal 43 (shown in Figure 1) to push potentially interfering tissue aside for enhanced detection of glucose levels in

subcutaneous tissue and blood vessels.

[00034] Figure 4 illustrates portions of outer wall 46” of another example chamber 24” of earbud 20 in various pressure states. Outer wall 46” is similar to outer wall 46’ except that outer wall 46” comprises connecting portions 54” in place of connecting portions 54. Connecting portions 54” are repeatedly folded relative to one another such that outer wall 46”is accordion-like. Figure 4 illustrates outer wall 46” when chamber 24” is in the first pressure state PS1 and when chamber 24” is in the fourth pressure state PS4. As should be appreciated, pressure adjuster 28 may actuate outer wall 46”to various intermediate pressure states PS2 and PS3. In some implementations, connecting portions 54” are both accordion-like and resiliently

flexible/stretchable.

[00035] In one implementation, light transmitting portion 52 and connecting portions 54, 54” extend completely about a longitudinal axis of chamber 24, forming an outer ring of flexible material. In such an

implementation, glucose level monitoring is independent of the orientation in which earbud 20 is inserted into ear canal 43. In yet other implementations, light transmitting portion 52 and connecting portions 54, 54”are located at specific discrete locations along the exterior of chamber 24’, 24”. For example, light transmitting portion 52 and connecting portions 54, 54” may extend along one side of chamber 24’, 24”.

[00036] In one implementation, the flexible portions of outer wall 46 or the connecting portions 54, 54” of outer walls 46’, 46” have a flexibility of at least 10 pm and no greater than 5 mm. In one implementation, the flexible portions of outer wall 46 are formed from a flexible polymer such as polydimethylsiloxane. In other implementations, the flexible portions of outer wall 46 are the connecting portions 54, 54”of outer walls 46’, 46” may be formed from other flexible materials.

[00037] Referring back to Figure 1 , pressure adjuster 28 comprises a mechanism that selectively adjusts the size of chamber 24, 24’, 24” to actuate the chamber 24, 24’, 24” between different pressure states, such as a different pressure states described above. In one implementation, pressure adjuster 28 comprises a single pressure adjusting member. In other implementations, pressure adjuster 28 may comprise multiple spaced pressure adjusting members. In one implementation, pressure adjuster 28 comprises a pump which inflates the interior of chamber 24, 24’, 24” to different inflated or pressure states. In other implementations, pressure adjuster 28 comprises other mechanisms to move portions of outer wall 46, 46’, 46”against the tissue of ear canal 43. For example, in other

implementations, pressure adjuster 28 may comprise a piezo member which changes shape in response to application of electrical current, a micro linear actuator, or a shape memory actuator.

[00038] In one implementation, pressure adjuster 28 actuates chamber 24, 24’, 24” between two states wherein pressure adjuster 28 may toggle between an on state and an off state. In one implementation, pressure adjuster 24 actuates chamber 24, 24’, 24” between greater than two selectable states. In one implementation, pressure adjuster 28 changes between the different states in response to signals from a controller connected to pressure adjuster 28 in a wired or in a wireless fashion. In one implementation, the controller may be provided as part of earbud 20. In yet another implementation, the controller may be provided as part of a remote device that is in communication with a transceiver of earbud 20. Examples of such a remote device include, but are not limited to, a smart phone, notebook computer, laptop computer, desktop computer or the like.

[00039] Optical emitter 32 comprises a device that emits and directs light (electromagnetic radiation) through outer wall 46, 46’, 46”towards the tissue of ear canal 43. In one implementation, optical emitter 32 emits light (EL) having an infrared or near infrared wavelength. In another implementation optical emitter 32 emits light having a green wavelength such where optical emitter 32 comprises a green light emitting diode. In still other

implementations, optical emitter 32 may comprise other light or

electromagnetic radiation emitters. Optical emitter 32 directs the light through outer wall 46 such that the light is reflected off of the tissue back to optical detector 36. In one implementation, optical emitter 32 is at a fixed light- emitting angle with respect to outer wall 46 and the surrounding adjacent tissue of ear canal 43. In another implementation, optical emitter 32 is pivotably supported so as to be a movable between various selected light- emitting angles with respect to outer wall 46, 46’, 46” and the adjacent tissue by an actuator. In some implementations, optical emitter 32 is pivoted or otherwise moved by an internal actuator in a controlled fashion relative to outer wall 46, 46’, 46”, such that the light emitted by optical emitter 32 is scanned across multiple distinct surfaces of the tissue of ear canal 43 when earbud 20 is monitoring glucose levels.

[00040] Optical detector 36 comprises a device to receive reflected light RL, light that has been reflected off of the tissue of ear canal 43 and output signals 57 that may indicate directly or indirectly glucose levels in the blood vessels or tissue. In one implementation, optical detector 36 may comprise a light sensitive diode, a light sensitive resistor, or an avalanche diode. In one implementation, optical detector 36 is connected to an analysis unit in a wired fashion. In other implementations, optical detector 36 is connected to an analysis unit in a wireless fashion.

[00041] Figure 5 schematically illustrates portions of an example noninvasive blood monitoring system 110. System 110 noninvasively monitors blood flow and/or blood content. In the example illustrated, system 110 noninvasively monitors glucose levels of a person or animal using an earbud position within an ear canal. System 110 comprises glucose monitoring earbud 120, input 160, controller 162, analysis unit 166 and glucose level indicator 176.

[00042] Earbud 120 is similar to earbud 20 described above except that earbud 120 additionally comprises sensor 168 and audio speaker 170. Those remaining components of earbud 120 which correspond to components of earbud 20 are numbered similarly. Sensor 168 comprise a sensor that outputs signals indicating motion of earbud 120. In one implementation, sensor 168 comprises at least one accelerometer. In another implementation, sensor 168 comprise a gyroscope. Signals from sensor 168 are transmitted to controller 162. In some implementations, sensor 168 may be omitted.

[00043] Audio speaker 170 comprise a speaker to emit sound for listening by the person wearing earbud 120. Such sound may be music, audible speech or the like. In the example illustrated, the speaker 170 is mounted at the end of earbud 120 closest to the farthest interior of ear canal 43. In other implementations, audio speaker 170 may be provided at other locations on earbud 120 or may be omitted.

[00044] Input 160 comprises a device by which selections, commands or other input is provided to controller 162. In one implementation, input 1/60 connected to controller 162 and a wired fashion. In other implementations, input 160 communicate with controller 162 and a wireless fashion, such as through Bluetooth or across a wireless network. In one implementation input 160 is provided as part of earbud 120. In yet another implementation, input 160 is provided as part of the remote device, such as a smart phone, notebook computer, laptop computer, desktop computer or the like, wherein commands or instructions are indicated wirelessly to controller 162, such as by Bluetooth or across a wireless network. Input 160 may comprise a keyboard, a touchpad, a touchscreen, a mouse, a microphone with associated speech recognition software and the like.

[00045] Controller 162 comprises at least one processing unit, consolidated at a single location or distributed at multiple locations, which outputs control signals for controlling pressure adjusters 28. Controller 162 controls the pressure state of outer wall 46, 46’ or 46”. For purposes of this disclosure, the term“processing unit” shall mean a presently developed or future developed computing hardware that executes sequences of instructions contained in a non-transitory memory 174. Execution of the sequences of instructions causes the processing unit to perform steps such as generating control signals. The instructions may be loaded in a random access memory (RAM) for execution by the processing unit from a read only memory (ROM), a mass storage device, or some other persistent storage. In other

embodiments, hard wired circuitry may be used in place of or in combination with software instructions to implement the functions described. For example, controller 162 may be embodied as part of one or more application-specific integrated circuits (ASICs). Unless otherwise specifically noted, the controller is not limited to any specific combination of hardware circuitry and software, nor to any particular source for the instructions executed by the processing unit.

[00046] Analysis unit 166 comprises at least one computing unit that estimates are determines a level of glucose in the tissue or blood based upon the signals provided by detector 36. Analysis unit 166 comprises processing unit 178 and non-transitory memory 180. Memory 180 contains instructions for directing processing unit 178 to determine a blood glucose level. In one implementation, the instructions contained in memory 180 direct processing unit 178 to compare values of the signals from the detector 36, indicating a degree or extent of light absorption by the tissue, to at least one lookup table which contains empirically obtained values correlating the values for signals from detector 36 to various glucose levels. In another implementation, instructions in memory 180 direct processing unit 178 to calculate an estimate for glucose levels based upon a formula, wherein the values of the signals are used as input to the formula. The determined blood glucose level or levels are output to glucose level indicator 176.

[00047] Glucose level indicator 176 comprises a visual or audible indicator which indicates a glucose level as determined by analysis unit 166.

In one implementation, glucose level indicator 176 outputs a visible or audible alert or alarm in response to the determined glucose level being above and/or below a predetermined threshold. In another implementation, glucose level indicator 176 provides a numerical value indicating the determined glucose level. In one implementation, glucose level indicator 176 may comprise a display or an LED. In another implementation, glucose level indicator 176 may comprise a speaker. In some implementations, glucose level indicator 176 outputs an audible alert or an audible value of the determined glucose level using speaker 170. In one implementation, glucose level indicator 176 is provided as part of earbud 120. In another implementation, glucose level indicator 176 is provided as part of a remote device, wherein analysis unit 166 communicates with the remote device such as a smart phone, laptop, notebook computer, desktop computer or the like in a wireless fashion. As shown by broken lines, in one implementation, glucose level indicator 176 and input 160 may be provided as part of a single device, such as a touchscreen on a smart phone, laptop, notebook computer, desktop computer or the like. [00048] Figure 6 is a diagram illustrating various example states for outer wall 46 of chamber 24 of earbud 120 under the control of controller 162. It should be appreciated that the illustrate states are equally applicable to an earbud 120 having chamber 24’ with outer wall 46’ or chamber 24” with outer wall 46” described above. As shown by Figure 6, controller 162 actuates pressure adjusters 28 to actuate wall 46 of chamber 24 to a withdrawn/insert state pressure 204, a non-monitoring state pressure 206 or a monitoring state pressure 208 based upon or in response to input/send signals 200. Signals 200 may be the result of input from the user via input 160. Likewise, signals 200 may be the result of signals from sensor 168 or output from analysis unit 166.

[00049] The withdrawn/insert state pressure 204 is a pressure that facilitates insertion or withdrawal of chamber 24 from ear canal 43. At such a pressure, the size of chamber 24 is sufficiently reduced for ease of insertion or withdrawal. In one implementation, controller 162 may control pressure adjuster 28 so as to actuate chamber 24 to the withdrawn/insert state pressure in response to user input via input 160 indicating that the user is about to withdraw chamber 24 from ear canal 43. The lower pressure may be maintained until earbud 120 is inserted back into ear canal 43 or until signals are received from input 160 causing controller 162 to actuate chamber 24 to a different state pressure.

[00050] The non-monitoring state pressure 206 is a pressure applied to the adjacent tissue that is greater than the withdrawn/insert state pressure 204 but less than the monitoring state pressure 208. The non-monitoring state pressure is sufficient to reliably retain earbud 120 within ear canal 43. In one implementation, controller 162 actuates chamber 24 to one of multiple various different non-monitoring state pressures, such as pressures (P1) 212 and (P2) 214. In one implementation, the user may select a non-monitoring state pressure state through input 160. In another implementation, controller 162 automatically selects which of the non-monitoring state pressures to apply based upon signals from sensor 168 indicating the activity level of the person wearing earbud 120. For example, controller 162 may actuate chamber 24 to a higher pressure state when signals from sensor 168 indicates that the person wearing earbud 120 is active, such as when the person is running, wherein the higher non-monitoring pressure state 212 may more reliably retain earbud 120 in place. Signals from sensor 168 indicating the person is relatively inactive or is stationary may result in controller 162 automatically actuating chamber 24 to a lower non-monitoring pressure state 214. In one implementation, controller 162 may select a particular non-monitoring state pressure based upon whether speaker 170 is being utilized, wherein a particular state pressure may enhance the blocking out of audible noise.

[00051] The monitoring state pressure 208 is a pressure that displaces tissue of ear canal 43 to provide enhanced glucose level monitoring. In one implementation, the monitor state pressure 208 is a pressure of at least 1 mm Hgand no greater than 300 mm Hg. As shown by broken lines, in some implementations, controller 162 may control pressure actuators 28 to adjust the monitor state pressure 208 based upon feedback or signals from analysis unit 166. For example, based upon signals 216 from optical detector 36, analysis unit 166 may provide feedback to controller 162 in the form of signals 200, wherein controller 162 adjusts the monitoring state pressure being applied by pressure adjusters 28. In one implementation, weak signals from the detector 36 are signals experiencing high degrees of signal noise may result in controller 162 increasing the monitoring state pressure 208.

[00052] In some implementations, controller 162 may automatically control pressure adjuster 28 to automatically actuate chamber 24 to the monitoring state pressure 208 from a non-monitoring state pressure 206. For example, in one implementation, controller 162 may be programmed so as to automatically actuate chamber 24 to the monitoring state pressure 208 at periodic or variably timed intervals. In another implementation, controller 162 may be programmed to automatically actuate chamber 24 to the monitoring state pressure 208 based upon signals from sensor 168. For example, signals from sensor 168 indicating that the person is active, such as when the person is running, may automatically trigger controller 162 to output control signals causing pressure adjuster 28 to actuate chamber 24 to the monitoring state pressure 208.

[00053] In some implementation, controller 162 may additionally control the operation of emitter 32, detector 36 and/or analysis unit 166. Controller 162 may output control signals initiating or stopping the output of light by emitter 32, initiating or stopping the detection of light by detector 36 and/or initiating or stopping the determination of glucose level by analysis unit 166 based upon whether system 1 10 is to actively monitor glucose at a particular time. For example, at those times that glucose monitoring is not to be performed, such components may be shut down to conserve power, such as conserve battery life my battery associated with earbud 120. In some implementations, controller 162 may initiate glucose monitoring based upon the activity level of the person wearing earbud 120, as detected by sensor 168. For example, controller 162 may initiate glucose monitoring by turning on the various components in response to receiving signals from sensor 168 indicating that the person is in an active state and is running.

[00054] Figure 7 schematically illustrates portions of an example noninvasive blood monitoring system 310. System 310 is similar to system 110 except that system 310 comprises earbud 320. Those remaining components of system 310 which correspond to components of system 110 are numbered similarly. As with system 110, system 310 noninvasively monitors the content and/or flow of blood. In the example illustrated, system 310 noninvasively monitors glucose levels.

[00055] Earbud 320 is similar earbud 120 except that chamber 24 comprises an inflatable chamber and that earbud 320 additionally comprises sensor 268. Sensor 268 comprise a sensor to sense an inflation level of chamber 24. In some implementations, sensor 268 may be incorporated into or as part of the pump forming pressure adjuster 328. Sensor 268 facilitates closed loop feedback control over the inflation level or pressure being applied by wall 46 against the tissue of ear canal 43.

[00056] The pump forming pressure adjuster 328 supplies a pressurized fluid to the interior of chamber 24. In one implementation, the pump is provided as part of earbud 320. In yet another implementation, the pump may be provided external of earbud 320. The pump forming pressure adjuster 328 may be controlled in response to signals from controller 162 or from input 160. For example, one implementation, the pump of pressure adjuster 28 may be controlled to actuate chamber 24 to any of the various states illustrated and described above with respect to Figure 6 in response to input/sense signals 200.

[00057] Figure 8 is a flow diagram of an example method 400 for noninvasively determining or monitoring a glucose level. Although method 400 is described with respect to monitoring a glucose level, at least portions of method 400 may also be applied to monitor other characteristics of blood, such as blood flow or concentrations of other elements, such as oxygen, within the blood. Although method 400 is described in the context of being carried out with system 310 and earbud 320, it should be appreciated that method 400 may be carried out with other systems and other earbuds having an inflatable chamber. As indicated by block 404, inflatable chamber 24 is inflated while within ear canal 43. Such inflation may occur in response to control signals output by controller 162 which cause pressure adjuster 328 to apply a monitoring state pressure to the tissue of the ear canal 43.

[00058] As indicated by block 406, optical detector 36 senses light L that is reflected off surfaces of ear canal 43 and that is passed through a light transmissive portion of a wall of inflatable chamber 46. As indicated by block 408, analysis unit 166 determines a glucose level based upon the sensed light, based upon the signals from detector 36. In other implementations, analysis unit 166 may determine blood flow, such as a blood pulse, or concentrations of other chemicals or elements in the blood based upon the sensed light.

[00059] Figure 9 is a flow diagram of an example method 500 for noninvasively detecting our monitoring glucose levels in a person or animal. Although method 500 is described with respect to monitoring a glucose level, at least portions of method 400 may also be applied to monitor other characteristics of blood, such as blood flow or concentrations of other elements, such as oxygen, within the blood. Although method 500 is described in the context of being carried out with system 310 and earbud 320, it should be appreciated that method 500 may be carried out with other systems and other earbuds having an inflatable chamber. As indicated by block 504, controller 162 outputs control signals to pressure adjuster 328 to inflate chamber 24 of earbud 320 within ear canal 43 to a first monitoring pressure inflation state.

[00060] As indicated by block 506, optical detector 36 senses a first light that is reflected off a surface of ear canal 43 that is passed through a light transmissive portion of a wall 46 of inflatable chamber 320 while the inflatable chamber 320 is in the first inflation state.

[00061] As indicated by block 514, controller 162 outputs control signals to pressure adjuster 328 to inflate chamber 24 of earbud 320 within ear canal 43 to a second monitoring pressure inflation state, different than the first monitoring pressure inflation state based upon the sensed first light, based upon signals received from detector 36. In one implementation, controller 162 adjusts the pressure of chamber 24 based directly upon signals from detector 36. In another implementation, controller 162 adjusts the pressure chamber 24 indirectly based upon signals from detector 36, based upon a detected glucose level from analysis unit 166 which is based upon signals from detector 36. For example, depending upon the strength of the signals or the amount of noise associated with received signals taken while chamber 24 was at the first inflation state, controller 162 may output control signals to pressure adjuster 328 increasing or decreasing the pressure of chamber 24.

[00062] In another implementation, controller 162 may output control signals causing pressure adjuster 328 to apply an initial pressure to chamber 24, wherein the pressure is gradually increased until signals received from optical detector 36 satisfy a predetermined threshold with respect to strength, noise and/or other characteristics. Conversely, in another implementation, controller 12 may output control signals causing pressure adjuster 328 to apply initial pressure to chamber 24, wherein the pressure is gradually decreased until signals received from optical detector 36 satisfy the predetermined threshold with respect to strength, noise and/or other signal characteristics. By scanning across a range of multiple pressures, controller 162 may identify a pressure level most suitable for the particular individual utilizing the earbud.

[00063] As indicated by block 516, optical detector 36 senses a second light that is reflected off surface of ear canal 43 and passed through the light transmissive portions of wall 46 of chamber 24 while the inflatable chamber 24 is in the second monitoring pressure inflation state. As indicated by block 518, analysis unit 166 determines a glucose level based upon the sensed light, based upon the signals from detector 36.

[00064] Figure 10 schematically illustrates portions of an example noninvasive blood monitoring system 610. In the example illustrated, blood monitoring system 610 monitors glucose levels. In other implementations, blood monitoring system 610 may monitor other blood characteristics, such as blood flow or concentrations of other chemicals or elements in the blood. System 610 is similar to system 310 except that system 610 comprises earbud 620 in place of earbud 320. Earbud 620 is similar to earbud 320 except that earbud 620 additionally comprises reflective surface 626. Those remaining components of system 610 which correspond to components of system 310 are numbered similarly

[00065] Reflective surface 626 comprises a surface that reflects the light emitted by emitter 32. Reflective surface 626 is supported by chamber 24 and is located between emitter 32 and detector 36 so as to reflect light emitted by emitter 32 that has previously reflected off of tissue of ear canal 43. Reflective surface 626 reflects the light back towards the tissue of ear canal 43 such that the light from emitter 32 interacts, reflects off of and bounces off of distinct surfaces of the tissue of ear canal 43 as shown by Figure 10. Although Figure 10 schematically illustrates the light reflecting off of reflective surface 626 three times and reflecting off of the tissue of ear canal 43 four times, it should be appreciated such is merely for purposes of illustration and that light may reflect off of surface 626 and the tissue of ear canal 43 a fewer or greater number of times before ultimately reaching detector 36. Because reflective surface 626 causes light to reflect off of multiple distinct, and sometimes spaced, surfaces of the tissue of ear canal 43, blood glucose level detection accuracy and/or reliability may be enhanced.

[00066] In one implementation, reflective surface 626 comprise a layer of a reflective material such as aluminum or aluminized mirror. In another implementation, selected portions of wall 46 are made reflective. In one implementation, reflective surface 626 is formed on an exterior surface of wall 46. In another implementation, reflective surface 626 is formed on an interior surface of wall 46. In one implementation, reflective surface 626 is

sandwiched between layers of wall 46. In yet other implementations, reflective 66 may be formed upon other surfaces, such as upon internal supporting structures within chamber 24, wherein the light passes through light transmissive portions of wall 46 and through at least portions of the interior of chamber 24 before being reflected off of the interior located reflective surface 626. [00067] Figures 11 and 12 illustrate portions of an example noninvasive blood monitoring system 710. In the example illustrated, blood monitoring system 710 monitors glucose levels. In other implementations, blood monitoring system 710 may monitor other blood characteristics, such as blood flow or concentrations of other chemicals or elements in the blood. System 710 is similar to system 610 except that system 710 comprises earbud 720 in place of earbud 620. Figure 11 illustrates the earbud 720 positioned within ear canal 43. Earbud 720 is similar earbud 620 except that earbud 720 further comprises core 725. Those components of system 710 and earbud 720 which correspond to components of system 610 and earbud 620 are numbered similarly.

[00068] Core 725 comprises a rigid structure located within the interior of chamber 24. Core 725 supports optical emitter 32, optical detector 36, pressure adjusters 328 in the forms of pumps, sensor 168, sensor 268 and reflective surface 626. In some implementations, sensor 268 may be incorporated as part of pressure adjusters 328. For example, in one implementation, pressure just the 328 may comprise an electro-osmotic (EO) pump which also acts as a flow sensor.

[00069] As further shown by Figure 12, in the example illustrated, core 725 has a hollow interior 727 to contain a fluid for being selectively pumped to the hollow interior of chamber 24 through passages 729 which extend through core 725. Pumps 729 pump fluid from interior 727 in response to signals from controller 162, as described above, to actuate chamber 24 to one of various pressure states (described above with respect to Figure 6).

[00070] In use, light output by optical matter 32 passes through the fluid filled interior of chamber 24, passes through light transmissive portions of outer wall 46 of chamber 24 and impinges tissue of ear canal 43. The light reflects off of tissue 43, returning back through wall 46 and through the fluid filled interior of chamber 24 to reflective surface 626 which reflects the light back towards a distinct tissue of ear canal 43. This process repeats until the light impinges and is detected by optical detector 36. Signals from optical detector 36 are communicated to analysis unit 166 which determines a glucose level, wherein the determined glucose level is displayed on glucose level indicator 176 or which causes an alert to be output by glucose level indicator 176.

[00071] Although the present disclosure has been described with reference to example implementations, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example implementations may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example implementations or in other alternative implementations. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example implementations and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements. The terms“first”,“second”,“third” and so on in the claims merely distinguish different elements and, unless otherwise stated, are not to be specifically associated with a particular order or particular numbering of elements in the disclosure.

Claims

WHAT IS CLAIMED IS:

1 1. An apparatus comprising:

2 a noninvasive blood monitoring earbud comprising:

3 a chamber sized for insertion into an ear canal, the

4 chamber formed by an outer wall, wherein at least a portion of the

5 outer wall is flexible;

6 a pressure adjuster to exert an adjustable pressure

7 against a surface of the ear canal; and

8 an optical emitter to direct light through the outer wall; 9 an optical detector to output signals in response to0 receiving the light reflected from the surface of the ear canal

1 through the outer wall. i 2. The apparatus of claim 1 further comprising an analysis unit to

2 determine and output a glucose reading based upon the signals.

1 3. The apparatus of claim 1 , wherein the optical emitter and the

2 optical detector are spaced and oriented relative to one another such that the

3 optical detector receives the light from the optical emitter after the light has

4 reflected off of the distinct surfaces of the ear canal multiple times.

1 4. The apparatus of claim 1 further comprising a core within the

2 chamber, wherein the core supports the optical detector and the optical emitter.

1 5. The apparatus of claim 3 further comprising an audio speaker

2 supported by the core and projecting beyond the chamber.

1 6. The apparatus of claim 3, wherein the core has an outer surface to

2 reflect the light. i 7. The apparatus of claim 1 , wherein the chamber is inflatable and

2 wherein pressure adjuster comprises a pump to inflate the chamber with a fluid.

1 8. The apparatus of claim 6, further comprising a core within the

2 chamber, wherein the core has a hollow interior to contain the fluid.

1 9. The apparatus of claim 6 further comprising:

2 a core within the chamber; and

3 an audio speaker supported by the core and projecting

4 beyond the chamber.

1 10. The apparatus of claim 1 , further comprising a controller to actuate

2 the pressure adjuster between a first monitoring state pressure level for

3 monitoring glucose levels and a second non-monitoring state pressure level less

4 than the first monitoring pressure level.

1 11. The apparatus of claim 9, wherein the controller is to actuate the

2 pressure adjuster to a third earbud withdrawing pressure level less than the

3 second non-monitoring state pressure level.

1 12. The apparatus of claim 1 further comprising a sensor to sense

2 motion of the earbud, wherein the controller is to adjust a pressure level based

3 upon the sensed motion of the earbud.

1 13. The apparatus of claim 1 further comprising a controller to control

2 the pressure adjuster, wherein the controller outputs control signals controlling

3 the pressure adjuster based upon the signals from the optical detector.

1 14. A method for noninvasively monitoring a glucose level with an

2 earbud, the method comprising: inflating an inflatable chamber of the earbud within an ear canal;

sensing light that has reflected off at least one surface of the ear canal and passed through a wall of the inflatable chamber; and

determining the glucose level based upon sensed light.

A noninvasive blood monitoring system comprising: an optical emitter to direct light at surfaces of an ear canal in which earbud is inserted;

an optical detector;

a reflective surface between the optical emitter and the optical detector such that the light from the optical emitter repeatedly reflects off the reflective surface and distinct surfaces of the ear canal prior to being sensed by the optical detector; and

an analysis unit to determine a blood characteristic based upon signals from the optical detector.