PATENT DOCUMENT

Publication Number: US-11559216-B1
Application Number: US-201715675543-A
Country: US
Kind Code: B1

Title: Integrated photodiode

Abstract:
This relates to one or more integrated photodiodes on a back surface of a PPG device. The one or more integrated photodiodes can reduce the gap between one or more windows and the active area of the photodiode(s) to increase the PPG signal strength without affecting the depth of light penetration into skin tissue. In some examples, the photodiode stackup can contact the surface of the windows. In some examples, the photodiode stackups can exclude a separate substrate. In some examples, the photodiode stackup can be deposited on the inner surface of the windows opposite the outer surface of the device. In some examples, the photodiode stackup can be deposited on the back surface and/or outer surface of the device. In this manner, PPG sensors can be included in the device without the need for extra layers and measurement accuracy can be improved due to lower light loss.

Claims:
The invention claimed is: 
     
       1. A mobile electronic device comprising:
 one or more light sensors configured to detect a light and configured to generate a signal indicative of the light; 
 one or more windows capable of allowing the light to pass through and configured to support the one or more light sensors; and 
 a back surface of a housing of the mobile electronic device coupled to the one or more windows, wherein:
 the one or more light sensors includes a plurality of layers comprising at least one light sensing film; 
 an active area of the one or more light sensors covers a full area of the one or more windows; 
 the one or more light sensors includes at least two light sensors; 
 a total active area of the at least two light sensors substantially occupies a full area of the back surface of the housing of the mobile electronic device; 
 the one or more light sensors do not have a light sensor substrate on the side of the one or more light sensors opposite the one or more windows; 
 the at least one light sensing film is adjacent to at least one window of the one or more windows, or a second film that is adjacent to the at least one window; and 
 at least one of the plurality of layers contacts one or more of:
 the back surface of the housing of the mobile electronic device, the at least one window, or the second film. 
 
 
 
     
     
       2. The mobile electronic device of  claim 1 , wherein:
 the one or more light sensors comprises a stackup; and 
 a surface of the stackup contacts a surface of the one or more windows. 
 
     
     
       3. The mobile electronic device of  claim 2 , wherein the stackup includes a p-type material, and the p-type material contacts the surface of the one or more windows. 
     
     
       4. The mobile electronic device of  claim 1 , further comprising:
 the second film located between the one or more windows and the one or more light sensors, wherein a surface of the second film contacts the one or more windows and another surface of the second film contacts the one or more light sensors, the second film excluding air. 
 
     
     
       5. The mobile electronic device of  claim 1 , wherein the one or more light sensors are disposed on a surface of the one or more windows, the surface is opposite from the back surface of the housing of the mobile electronic device, and an active area of the one or more light sensors faces towards the back surface of the housing of the mobile electronic device. 
     
     
       6. The mobile electronic device of  claim 1 , further comprising:
 a plurality of conductive pads; and 
 a plurality of routing traces, each routing trace coupled to one of one or more light emitters or the one or more light sensors and configured to route one or more signals between at least one of the one or more light emitters or the one or more light sensors and at least one of the plurality of conductive pads, 
 wherein the plurality of routing traces and the plurality of conductive pads are disposed on a surface of a back surface, the surface of the back surface located away from the back surface of the housing of the mobile electronic device. 
 
     
     
       7. The mobile electronic device of  claim 1 , further comprising:
 a plurality of conductive pads; 
 a plurality of vias; 
 a plurality of first routing traces, each first routing trace coupled to a one of the one or more light emitters or the one or more light sensors and configured to route one or more signals between at least one of the one or more light emitters or the one or more light sensors and at least one of the plurality of vias; and 
 a plurality of second routing traces, each second routing trace coupled to at least one of the plurality of vias and configured to route one or more signals between the at least one of the plurality of vias and at a least one of the plurality of conductive pads. 
 
     
     
       8. The mobile electronic device of  claim 1 , further comprising:
 one or more conductive pads configured to route one or more signals to at least one of a one or more light emitters or at least one of the one or more light sensors, 
 wherein the one or more conductive pads are located in an outer perimeter of the back surface of the housing of the mobile electronic device. 
 
     
     
       9. The mobile electronic device of  claim 1 , further comprising:
 a coating contacting the one or more light sensors and configured to protect the one or more light sensors, wherein the one or more light sensors are located between the coating and the back surface of the housing of the mobile electronic device. 
 
     
     
       10. The mobile electronic device of  claim 9 , wherein the coating includes a black ink. 
     
     
       11. The mobile electronic device of  claim 1 , wherein at least one of the one or more light sensors is a black photodiode. 
     
     
       12. The mobile electronic device of  claim 1 , wherein a surface of one of the plurality of layers included in the one or more light sensors is opposite from an inner surface of the electronic device and an active area of the one or more light sensors faces towards the back surface of the housing of the mobile electronic device. 
     
     
       13. The mobile electronic device of  claim 1 , further comprising:
 an isolation located between the at least two light sensors and configured to electrically isolate the at least two light sensors. 
 
     
     
       14. A method for detecting physiological signals, comprising:
 emitting light from one or more light emitters to one or more windows without first transmitting through a layer of air; 
 allowing the emitted light to pass through the one or more windows coupled to a back surface of a housing of a mobile electronic device; 
 detecting a portion of a reflected light from tissue using one or more light sensors, the one or more light sensors comprising a light sensing film adjacent to at least one of:
 the back surface of the housing of the mobile electronic device; 
 a window of the one or more windows; or 
 a second film that is adjacent to the window; and 
 
 generating, using the one or more light sensors, one or more signals indicative of the reflected light, wherein:
 an active area of the one or more light sensors covers a full area of the one or more windows; 
 the one or more light sensors includes at least two light sensors; 
 a total active area of the at least two light sensors substantially occupies a full area of the back surface of the housing of the mobile electronic device; and 
 the one or more light sensors do not have a light sensor substrate on the side of the one or more light sensors opposite the window. 
 
 
     
     
       15. The method of  claim 14 , wherein emitting light from the one or more light emitters to the one or more windows comprises:
 emitting light from the one or more light emitters to a coating, and 
 allowing the emitted light to pass through the coating to the one or more windows. 
 
     
     
       16. The method of  claim 15 , wherein emitting light from the one or more light emitters to the one or more windows comprises:
 transmitting the reflected light through a sensor-window interface. 
 
     
     
       17. The method of  claim 15 , wherein emitting light from the one or more light emitters to the one or more windows comprises:
 transmitting the reflected light through a second film-window interface, wherein the second film excludes air.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Patent Application No. 62/374,438 filed Aug. 12, 2016, the contents of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     FIELD 
     This relates generally to a device that measures optical signal(s), and, more particularly, to one or more integrated photodiodes on a back surface of the device. 
     BACKGROUND 
     A device can include one or more photodiodes located on a back surface of the device, where the photodiodes can be configured for measuring one or more optical properties. For example, the photodiodes can be used to measure ambient light and/or determine whether the user&#39;s wrist is located in close proximity to the device. Another exemplary use for photodiodes can include photoplethysmographic (PPG) sensing. PPG sensing can include measuring optical signals to derive corresponding physiological signals (e.g., a pulse rate). In a basic form, PPG systems can employ a light source or light emitter that injects light into the user&#39;s tissue, and a light sensor to receive light that can reflect and/or scatter and can exit the tissue. The received light can include light with an amplitude that is modulated as a result of pulsatile blood flow (i.e., “signal”) and parasitic, non-signal light with an amplitude that can be modulated (i.e., “noise” or “artifacts”) and/or unmodulated (i.e., DC). However, in some examples, the path length of reflected and/or scattered light received by the light sensor may be long, which can result in a low signal strength and difficulty in accurately determining the user&#39;s pulse rate. 
     One way to increase the signal intensity or signal strength can be to decrease the distance between the light sensor and light emitter. Although the lateral separation between the light sensor and light emitter can be reduced, such change in lateral separation can affect the depth that the light can penetrate into the skin. An alternative way to increase the signal strength without affecting the depth of light penetration may be needed. 
     SUMMARY 
     This relates to one or more integrated photodiodes on a back surface (e.g., underside) of a PPG device. The one or more integrated photodiodes can reduce the gap between one or more windows and the active area of the photodiode(s) (i.e., light sensor(s)) to increase the PPG signal strength without affecting the depth of light penetration into skin tissue. In some examples, the photodiode stackup can contact the surface of the windows. In some examples, the photodiode stackups can exclude a separate substrate. In this manner, PPG sensors can be included in the device without the need for extra layers (e.g., a separate substrate), which can result in improved measurement accuracy and reduced power consumption due to lower light loss. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A- 1 C  illustrate systems in which examples of the disclosure can be implemented. 
         FIG.  2 A  illustrates a top view of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  2 B  illustrates a cross-sectional view of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  2 C  illustrates a partial bottom view of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  2 D  illustrates a cross-sectional view of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  2 E  illustrates an exemplary method for operating an electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  2 F  illustrates an exemplary method for fabricating an electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  3 A  illustrates a partial bottom view of an exemplary electronic device including integrated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  3 B  illustrates a cross-sectional view of an exemplary electronic device including integrated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  3 C  illustrates a partial bottom view of an exemplary electronic device including integrated photodiodes for PPG measurements according to examples of the disclosure. 
         FIG.  3 D  illustrates a cross-sectional view of an exemplary electronic device including support and backing according to examples of the disclosure. 
         FIG.  3 E  illustrates an exemplary method for operating an electronic device including integrated photodiodes according to examples of the disclosure. 
         FIG.  3 F  illustrates an exemplary method for fabricating an exemplary electronic device including integrated photodiodes according to examples of the disclosure. 
         FIG.  4 A  illustrates a top view of an exemplary electronic device including integrated photodiodes disposed on a back surface according to examples of the disclosure. 
         FIG.  4 B  illustrates a cross-sectional view of an exemplary electronic device including integrated photodiodes disposed on a back surface according to examples of the disclosure. 
         FIG.  4 C  illustrates a top view of an exemplary electronic device including a plurality of integrated photodiodes disposed on a back surface according to examples of the disclosure. 
         FIG.  4 D  illustrates an exemplary method for operating an electronic device including a plurality of integrated photodiodes according to examples of the disclosure. 
         FIG.  4 E  illustrates an exemplary method for fabricating an exemplary electronic including one or more integrated photodiodes according to examples of the disclosure. 
         FIG.  5 A  illustrates a top view of an exemplary device including a sensor according to examples of the disclosure. 
         FIG.  5 B  illustrates a top view of an exemplary device including a sensor according to examples of the disclosure. 
         FIG.  6    illustrates a cross-sectional view of an exemplary electronic device including one or more integrated photodiodes according to examples of the disclosure. 
         FIG.  7    illustrates an exemplary block diagram of a computing system comprising light emitters and light sensors for measuring a signal associated with a user&#39;s physiological state according to examples of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples, reference is made to the accompanying drawings in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the various examples. 
     In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects and/or features described or referenced herein. It will be apparent, however, to one skilled in the art, that one or more aspects and/or features described or referenced herein may be practiced without some or all of these specific details. 
     Representative applications of methods and apparatus according to examples of the present disclosure are described in this section. These examples are being provided solely to add context and aid in the understanding of the described examples. It will thus be apparent to one skilled in the art that the described examples may be practiced without some or all of the specific details. In other instances, well-known process steps have been described in detail in order to avoid unnecessarily obscuring the described examples. Other applications are possible, such that the following examples should not be taken as limiting. 
     A device can include one or more photodiodes located on a back surface of the device, where the photodiodes can be configured for measuring one or more optical properties. For example, the photodiodes can be used to measure ambient light and/or determine whether the user&#39;s wrist is located in close proximity to the device. Conventionally, the photodiodes are formed and located on a substrate separate from a surface (e.g., a back surface included in the external housing) of the device. In some instances, integrating the photodiode(s) can allow the photodiode to be located closer to objects (e.g., the user&#39;s wrist) of interest and can decrease fabrication complexity, for example. 
     A photoplethysmographic (PPG) signal can be measured by PPG systems to derive corresponding physiological signals (e.g., pulse rate). Such PPG systems can be designed to be sensitive to changes in blood in a user&#39;s tissue that can result from fluctuations in the amount or volume of blood or blood oxygen in the vasculature of the user. In a basic form, PPG systems can employ a light emitter (or light source) that injects light into the user&#39;s tissue, and a light sensor (or light detector) that can receive light that reflects and/or scatters and exits the tissue. The PPG signal is the amplitude of reflected and/or scattered light that can be modulated with volumetric change in blood volume in the tissue. In some examples, the path length of reflected and/or scatter light received by the light sensor may be long, which can result in a low signal strength and difficulty in accurately determining the user&#39;s pulse rate. One way to increase the signal intensity or signal strength can be to decrease the distance between the light sensor and light emitter. Although the lateral separation between the light sensor and light emitter can be reduced, such change in lateral separation can affect the depth that the light can penetrate into the skin. An alternative way to increase the signal strength without affecting the depth of light penetration may be needed. 
     This disclosure relates to one or more integrated photodiodes on a back surface of a PPG device. The one or more integrated photodiodes can reduce the gap between one or more windows and the active area of the photodiode(s) (i.e., light sensor(s)) to increase the PPG signal strength without affecting the depth of light penetration into skin tissue. In some examples, the photodiode stackup can contact the surface of the windows. In some examples, the photodiode stackups can exclude a separate substrate. In this manner, PPG sensors can be included in the device without the need for extra layers (e.g., a separate substrate), and measurement accuracy can be improved due to lower light loss. Although the disclosure discusses integrated photodiodes in the context of a PPG device and PPG measurements, examples of the disclosure are not so limited and can be applied to other types of devices and applications associated with optical sensing. 
       FIGS.  1 A- 1 C  illustrate systems in which examples of the disclosure can be implemented.  FIG.  1 A  illustrates an exemplary mobile telephone  136  that can include a touch screen  124 .  FIG.  1 B  illustrates an exemplary media player  140  that can include a touch screen  126 .  FIG.  1 C  illustrates an exemplary wearable device  144  that can include a touch screen  128  and can be attached to a user using a strap  146 . The systems of  FIGS.  1 A- 1 C  can utilize the integrated photodiodes as disclosed. 
       FIG.  2 A  illustrates a top view and  FIG.  2 B  illustrates a cross-sectional view (along the line A-AA indicated in  FIG.  2 A ) of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. Device  200  can include light emitter  206 , light emitter  208 , light emitter  216 , and light emitter  218  located on a surface of device  200 . Device  200  can further include light sensor  204  and light sensor  214  located on the surface of device  200 . Light emitter  206 , light emitter  208 , light emitter  216 , light emitter  218 , light sensor  204 , and light sensor  214  can be configured with each active area facing towards skin  220  of a user. Light emitter  206 , light emitter  208 , light emitter  216 , and light emitter  218  can be any type of light source, including but not limited to, light emitting diodes (LEDs), incandescent lights, fluorescent lights, organic light emitting diodes (OLEDs), and electroluminescent diodes (ELDs). Light sensor  204  and light sensor  214  can be any type of optical sensing device such as a photodiode. In some examples, light emitter  206  and light emitter  216  can be the same type of light emitter. In some examples, light emitter  208  and light emitter  218  can be the same type of light emitter. In some examples, light emitter  206  and light emitter  216  can be configured to emit a first wavelength, and light emitter  208  and light emitter  218  can be configured to emit a second wavelength, different from the first wavelength. In some examples, light sensor  204  and light sensor  214  can be symmetrically placed (i.e., located the same distance away) with respect to the center of back surface  221 . 
     Windows  201  can be located between the optical components (e.g., light sensor  204  and light sensor  214 ) and skin  220  (and/or the surface of device  200 ). Light emitter  208  can emit light  222 . A portion of light  222  can be absorbed by one or more vasculature structures located in skin  220 , and a portion of light  222  can reflect back as light  223 . Light sensor  204  can detect light  223  and can generate a signal indicative of one or more properties of light  223 . Light emitter  206  can emit light  224 . A portion of light  224  can be absorbed by one or more vasculature structures located in skin  220 , and a portion of light  224  can reflect back as light  225 . Light sensor  204  can detect light  225  and can generate a signal indicative of one or more properties of light  225 . A processor or controller can receive the signals generated by light sensor  204  and can utilize the information included in the signals to determine the user&#39;s physiological signals. 
       FIG.  2 C  illustrates a partial bottom view and  FIG.  2 D  illustrates a cross-sectional view (along the line B-BB indicated in  FIG.  2 A ) of an exemplary electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. Back surface  221  can include ledge  248 . Ledge  248  can be any type of physical structure configured to provide mechanical support to one or more optical components. Light sensor  204  and light sensor  214  can be mounted or formed on the same substrate  205 . In some examples, light sensor  204  and light sensor  214  can include discrete optical components.  FIG.  2 C  shows the active areas of light sensor  204  and light sensor  214 . When device  200  is assembled, the active areas of light sensor  204  and light sensor  214  can be facing windows  201 , as illustrated in  FIG.  2 D . 
     Ledge  248  can have a height  247 , which can cause light sensor  204  and light sensor  214  to be seated a fixed distance away from windows  201  or from the surface of back surface  221 . As a result, gap  246  can exist between window  201  and the active area of light sensor  204 . Additionally, gap  246  can exist between window  201  and the active area of light sensor  214 . In some examples, gap  246  can be 0.8 mm. In some examples, gap  246  can be 1 mm. Gap  246  can cause loss of reflected light, preventing the reflected light from reaching the active area of light sensor  204  and light sensor  214 . The loss of reflected light can result in decreased photodiode efficiency, which can lead to degradation in the generated signals. Degradation in the generated signals can require the system to increase the power of light emitted by the light emitters (e.g., light emitter  206 , light emitter  208 , light emitter  216 , and light emitter  218 ) and/or can result in poor measurement accuracy. 
       FIG.  2 E  illustrates an exemplary method for operating an electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. In step  252  of process  250 , light emitter (e.g., light emitter  208 ) can emit light (e.g., light  222 ) towards the user (e.g., skin  220 ). In step  254  of process  250 , light can pass through a window (e.g., window  201 ). In step  256  of process  250 , light can exit the window (e.g., window  201 ) and the device (e.g., device  200 ). In step  258  of process  250 , light (e.g., light  222 ) can enter the skin tissue (e.g., skin  220 ). A portion of light can be absorbed by one or more vasculatures included in the skin, and a portion of light (e.g., light  223 ) can reflect back to the device (e.g., device  200 ). In step  260  of process  250 , the reflected light (e.g., light  223 ) can enter the device and can pass through the window (e.g., window  201 ). In step  262  of process  250 , the reflected light (e.g., light  223 ) can pass through the gap (e.g., gap  246 ) between the window (e.g., window  201 ) and light sensor (e.g., light sensor  204 ). In step  264  of process  250 , the reflected light (e.g., light  223 ) can be incident on the active area of light sensor (e.g., light sensor  204 ), and the light sensor can generate one or more signals including reflected light information. In step  266  of process  250 , the user&#39;s physiological signal can be determined based on the reflected and/or back-scattered light information. 
       FIG.  2 F  illustrates an exemplary method for fabricating an electronic device including dedicated photodiodes for PPG measurements according to examples of the disclosure. In step  272  of process  270 , dedicated (i.e., separately fabricated, packaged, and/or diced) light emitters (e.g., light emitter  206  and light emitter  208 ) can be fabricated. In step  274  of process  270 , dedicated light sensors (e.g., light sensor  204  and light sensor  214 ) can be fabricated. In step  276  of process  270 , the back surface (e.g., back surface  221 ) can be formed. In step  278  of process  270 , apertures can be formed in the back surface for the optical components. In step  280  of process  270 , windows (e.g., window  201 ) can be attached at the location(s) of the apertures. In step  282  of process  270 , one or more ledges (e.g., ledge  248 ) can be formed in the back surface (e.g., back surface  221 ). In step  284  of process  270 , one or more light emitters (e.g., light emitter  206  and light emitter  208 ) can be attached to the back surface (e.g., back surface  221 ). In step  286  of process  270 , one or more light sensors (e.g., light sensor  204  and light sensor  214 ) can be attached to the back surface (e.g., back surface  221 ). In some examples, a plurality of wires can be attached to the light emitters and light sensors. In step  290  of process  270 , the back surface assembly (i.e., back surface and attached light emitters, light sensors, and windows) can be attached to the device (e.g., device  200 ). 
     One way to increase the signal intensity or signal strength can be to decrease the separation distance between a light sensor and a light emitter. Although the lateral separation between the light sensor and light emitter can be reduced, such change in lateral separation can affect the depth that the light can penetrate into the skin. An alternative way to increase the signal strength without affecting the depth of light penetration may be needed. 
       FIG.  3 A  illustrates a partial bottom view and  FIG.  3 B  illustrates a cross-sectional view of an exemplary electronic device including integrated photodiodes for PPG measurements according to examples of the disclosure. Device  300  can include a plurality of apertures  302 . Apertures  302  can be configured to allow light to pass through. In some examples, windows  301  can be located in close proximity to apertures  302 . Device  300  can further include back surface  321 . 
     To reduce the gap between the windows and the active area of the light sensors, photodiode stackup  304  can be deposited on window  301  and photodiode stackup  306  can be deposited on window  301 . In some examples, photodiode stackup  306  can contact the surface of window  301  and can be integrated into back surface  321 . That is, the photodiodes may not be separately packaged and/or fabricated. Photodiode stackup  304  and photodiode stackup  306  can include one or more layers that form the photodiode such as the P and N layers in a PN photodiode. In some examples, photodiode stackup  304  and photodiode stackup  306  can be formed without a separate substrate (i.e., a base layer upon which a material is deposited onto). In some examples, photodiode stackup  304  and photodiode stackup  306  can be deposited on the same window. In some examples, photodiode stackup  304  and photodiode stackup  306  can be deposited on different windows. In some examples, one or more layers, excluding air, can be included in the photodiode stackup and can be located between window  301  and a photodiode stackup. In some examples, the one or more layers can contact window  301  (i.e., reflected light can pass through a layer-window interface). The one or more layers can include, but are not limited to, silicon dioxide and titanium dioxide. In this manner, PPG sensors can be included in device  300  without the need for extra layers (e.g., a separate substrate), and measurement accuracy can be improved due to lower light loss. 
     Plurality of traces  319  can contact photodiode stackup  304  and can be configured for routing signals to and from the photodiode stackup  304  to plurality of pads  317 . Additionally, plurality of traces  319  can contact photodiode stackup  306  and can be configured for routing signals to and from the photodiode stackup  306  to plurality of pads  317 . Plurality of pads  317  can be configured to allow one or more electrical connectors to transmit and/or receive signals to/from a photodiode stackup. In some examples, plurality of traces  319  and/or plurality of pads  317  can be printed/deposited on back surface  321 . In some examples, plurality of traces  319  and/or plurality of pads  317  can contact back surface  321 . In some examples, plurality of traces  319  and/or plurality of pads  317  can be deposited on the side of back surface  321  opposite skin  320  and/or window  301 . In some examples, at least a portion of plurality of traces  319  can be sputtered on the sidewall of back surface  321 . In some examples, plurality of traces  319  and/or plurality of pads  317  can include conductive ink. In some examples, device  300  can include a conductive glue to connect plurality of traces  319  to a photodiode stackup. 
     In some examples, windows  301  can be configured to provide mechanical support to photodiode stackup  304  and photodiode stackup  306 . Windows  301  can also be transparent and can be configured to allow light to pass through. In some examples, windows  301  can include sapphire. In some examples, windows  301  can further be configured to protect photodiode stackup  304  and photodiode stackup  306  from unwanted environmental conditions (e.g., dust, external forces or pressure, moisture, etc.) In some examples, windows  301  can include Fresnel lenses. 
     In some examples, one or more of photodiode stackup  304  and photodiode stackup  306  can be configured to obscure the optical components from the human eye. In some examples, photodiode stackup  304  and/or photodiode  306  can be formed by sputtering black photodiodes. 
     In some examples, windows  301  can include zirconia. The zirconia windows can be configured to be transparent or semi-transparent by adjusting the thickness of the window, for example (e.g., the zirconia window can be made thinner for better transparency). The zirconia material can obscure the optical components from the human eye while also allowing light to pass through to the photodiode stackup(s). 
       FIG.  3 C  illustrates a partial bottom view of an exemplary electronic device including integrated photodiodes for PPG measurements according to examples of the disclosure. In some examples, signals to and from photodiode stackups can be routed by way of plurality of traces  319  and/or plurality of vias  315 . In some examples, plurality of vias  315  can be configured to allow photodiode stackups to be routed on one side of back surface  321 . In some examples, plurality of pads  317  can be located on another side of back surface  321  (not shown). 
     The electronic device can include one or more additional layers for cosmetic purposes, support purposes, or both.  FIG.  3 D  illustrates a cross-sectional view of an exemplary electronic device including support and backing according to examples of the disclosure. Device  300  can include a backing  322  disposed on photodiode stackup  340  and photodiode stackup  306 . Backing  322  can be included for aesthetic purposes. In some examples, backing  322  can include one or more layers of black ink. In some examples, the thickness of the photodiode can be increased for aesthetic purposes. Support  324  can be disposed on backing  322 . Support  324  can be configured for providing support and/or protection to photodiode stackup  304 , photodiode stackup  306 , and/or backing  322 . In some examples, support  324  can include an epoxy. In some examples, support  324  can include a dielectric coating. In some examples, backing  322  can be configured for providing support and/or protection. In some examples, a protective layer (e.g., a neutral layer) can be inserted between backing  322  and support  324 . 
       FIG.  3 E  illustrates an exemplary method for operating an electronic device including integrated photodiodes according to examples of the disclosure. In step  352  of process  350 , light emitter (e.g., light emitter  308 ) can emit light towards the user (e.g., skin  320 ). In step  354  of process  350 , light can pass through a window (e.g., window  301 ). In step  356  of process  350 , light can exit the window (e.g., window  301 ) and the device (e.g., device  300 ). In step  358  of process  350 , light can enter the skin tissue (e.g., skin  320 ). A portion of light can be absorbed by one or more vasculatures included in the skin, and a portion of light can reflect back to the device (e.g., device  300 ). In step  360  of process  350 , the reflected light can pass through the window (e.g., window  301 ). In step  362  of process  350 , the reflected light can be incident on the photodiode stack (e.g., photodiode stackup  304  and photodiode stackup  306 ) and/or one or more layers, excluding air, located between a window and the photodiode stackup. In some examples, reflected light exiting the window may not have to pass through air. The photodiode stackup can generate one or more signals that can be transmitted to a processor or controller using the plurality of traces (e.g., plurality of traces  319 ) and the plurality of pads (e.g., plurality of pads  317 ). In step  364  of process  350 , the user&#39;s physiological signal can be determined based on the reflected and/or back-scattered light information. 
       FIG.  3 F  illustrates an exemplary method for fabricating an exemplary electronic device including integrated photodiodes according to examples of the disclosure. In step  372  of process  370 , dedicated light emitters can be fabricated. In step  374  of process  370 , the back surface (e.g., back surface  321 ) can be formed. In step  376  of process  370 , apertures (e.g., apertures  302 ) can be formed in the back surface for the optical components (e.g., light emitters and light sensors). In step  378  of process  370 , each photodiode stackup (e.g., photodiode stackup  304  and photodiode stackup  306 ) can be deposited on the windows (e.g., window  301 ). In step  380  of process  370 , the light emitters can be attached to the back surface (e.g., back surface  321 ). In step  382  of process  370 , the windows (e.g., window  301 ) can be attached at the location of the apertures. In some examples, the photodiode stackup can be deposited on the windows after attaching the windows at the location of the apertures. In step  384  of process  370 , the back surface assembly (i.e., back surface, attached light emitters and windows, and deposited light sensors) can be attached to the device (e.g., device  300 ). In some examples, the photodiode stackup can be deposited on the windows prior to the windows being attached to the back surface. 
       FIG.  4 A  illustrates a top view and  FIG.  4 B  illustrates a cross-sectional view of an exemplary electronic device including integrated photodiodes disposed on a back surface according to examples of the disclosure. Device  400  can include light emitter  406 , light emitter  408 , light emitter  416 , and light emitter  418  optically coupled to a window  401 . In some examples, each light emitter can be optically coupled to a different window. In some examples, two or more light emitters can be optically coupled to the same window. Device  400  can be configured with one or more photodiodes located on an exterior surface. The exterior surface can be the surface of device  400  closer to skin  420  and/or the surface shared by windows  401 . As illustrated in  FIG.  4 B , photodiode stackup  404  can be deposited on back surface  421 , thereby minimizing any gap between the photodiode and skin  420 . To protect photodiode stackup  404  from unwanted environmental conditions (e.g., dust, external forces, moisture, etc.), coating  405  can be deposited on photodiode stackup  404 . In some examples, coating  405  can be located between photodiode stackup  404  and skin  420  (and/or the surface of window  401 ). The light emitters (e.g., light emitter  418 ) can be configured to emit light (e.g., light  422 ). Light can pass through window  401 . A portion of light can be absorbed by one or more vasculature structures located in skin  420 , and a portion of light (e.g., light  423 ) can reflect back. The reflection of light can pass through coating  405  and can be incident on the active area of photodiode stackup  404 . Photodiode stackup  404  can generate one or more signals including reflected light information. The one or more signals can be transmitted to a controller or processor through one or more routing traces and/or pads (not shown). In some examples, routing traces and/or pads can be located along the perimeter of the back surface. In some examples, routing traces and/or pads can be located on the side of back surface opposite from the side with coating  405 . By disposing photodiode stackup  404  on back surface  421 , the photodiode can have a larger active area, which can enhance the photodiode&#39;s sensitivity and ability to detect signals having smaller intensities. 
       FIG.  4 C  illustrates a top view of an exemplary electronic device including a plurality of integrated photodiodes disposed on a back surface according to examples of the disclosure. In some examples, back surface  421  can be configured to support a plurality of photodiode stackups, such as photodiode stackup  404  and photodiode stackup  414 . The plurality of photodiode stackups can be separated by isolation  407 . Isolation  407  can include any type of material, including but not limited to, a dielectric insulator. In some examples, isolation  407  can include an air gap. In some examples, the plurality of photodiode stackups can appear to the human eye to be a single, continuous photodiode due to the controlled spacing of isolation  407  (e.g., less than 10 micron spacing). In some examples, isolation  407  can be 5 microns wide. In some examples, isolation  407  can be 1 micron wide. In some examples, isolation  407  can include routing traces. 
     Although  FIG.  4 C  illustrates each of the plurality of photodiode stackups as having triangular shapes, examples of the disclosure can include any shape, including but not limited to, squares, circles, and ovals. Although  FIG.  4 C  illustrates the plurality of photodiode stackups as deposited on back surface  421 , examples of the disclosure can include the plurality of photodiode stacks deposited on any surface, including but not limited to, the housing (e.g., area outside of back surface  421 ) of device  400 . 
       FIG.  4 D  illustrates an exemplary method for operating an electronic device including a plurality of integrated photodiodes according to examples of the disclosure. In step  452  of process  450 , light emitter (e.g., light emitter  408 ) can emit light towards the user (e.g., skin  420 ). In step  454  of process  450 , light can pass through a window (e.g., window  401 ). In step  456  of process  450 , light can exit the window (e.g., window  401 ) and the device (e.g., device  400 ). In step  458  of process  450 , light can enter the skin tissue (e.g., skin  420 ). A portion of light can be absorbed by one or more vasculatures included in the skin, and a portion of light can reflect back to the device (e.g., device  400 ). In step  460  of process  450 , the reflected light can pass through one or more coatings (e.g., coating  405 ). In step  462  of process  450 , the reflected light can be incident on the photodiode stackup (e.g., photodiode stackup  404  and photodiode stackup  406 ). The photodiode stackup can generate one or more signals that can be transmitted to a processor or controller using the plurality of traces (e.g., plurality of traces  419 ) and the plurality of pads (e.g., plurality of pads  417 ). In step  464  of process  450 , the user&#39;s physiological signal can be determined based on the reflected light information. 
       FIG.  4 E  illustrates an exemplary method for fabricating an exemplary electronic device including one or more integrated photodiodes according to examples of the disclosure. In step  472  of process  470 , dedicated light emitters can be fabricated. In step  474  of process  470 , the back surface (e.g., back surface  421 ) can be formed. In step  476  of process  470 , apertures (e.g., apertures  402 ) can be formed for the optical components (e.g., light emitters and light sensors). In step  478  of process  470 , windows (e.g., window  401 ) can be attached at the location of the apertures. In step  480  of process  470 , the light emitters can be attached to the back surface (e.g., back surface  421 ). In step  482  of process  470 , photodiode stackup (e.g., photodiode stackup  404  and photodiode stackup  406 ) can be deposited on the back surface (e.g., back surface  421 ). In step  484  of process  470 , one or more coatings (e.g., coating  405 ) can be deposited on photodiode stackup (e.g., photodiode stackup  404  and photodiode stackup  406 ). In step  486  of process  470 , the back surface assembly (i.e., back surface, attached light emitters and windows, and deposited light sensors) can be attached to the device (e.g., device  400 ). 
     Although the figures illustrate the photodiode stackup integrated into the back surface and utilized for PPG measurements, examples of the disclosure can include the photodiode stackup integrated into any material (e.g., housing) of the electronic device and utilized for any type of optical measurement (e.g., ambient light sensing).  FIG.  5 A  illustrates a top view of an exemplary device including a sensor according to examples of the disclosure. Device  504  can include display  506  and border region  510 . Display  506  can any type of touch sensitive component capable of sensing touch and/or hover. Border region  510  can be a region of device  504  located between edge of device  504  and display  506 . Sensor  508  can be located in border region  510  and can be configured for sensing any type of light, including, but not limited to, ambient light. In some examples, sensor  508  can be placed in close proximity to the illuminating component (e.g., display or indicator lights) being controlled and can be facing the direction where light originates. For example, display  506  can include a display capable of projecting one or more images on the screen. Sensor  508  can be located in border region  510 , which can be in close proximity to display  506  to sense the ambient light in the room or surrounding area. Based on the sensed ambient light, device  504  can adjust the brightness of the display  506 . 
     In some examples, sensor  508  can be included in display  506 .  FIG.  5 B  illustrates a top view of an exemplary device including a sensor according to examples of the disclosure. Sensor  508  can be relocated to one or more locations closer to display  506  than a sensor located in border region  510  (as illustrated in  FIG.  5 A ). In some examples, sensor  508  can be placed underneath display  506  in such a way as to allow the sensor to function through the display and/or any touch screen coupled to the display. In some examples, sensor  508  can be placed on top of display  506  in such a way as to not hinder the ability of the display to project content through or around the sensor. In some examples, sensor  508  can be incorporated into the structure of touch screen  506  (i.e., the sensor can be manufactured in the same process layers as the display and/or touch screen). 
     To enhance the accuracy of sensed light and/or to reduce the number of layers in the stackup, examples of the disclosure can include one or more integrated photodiodes on a cover material and/or housing of the device.  FIG.  6    illustrates a cross-sectional view of an exemplary electronic device including one or more integrated photodiodes according to examples of the disclosure. Device  600  can include cover material  614  and display  606 . In some examples, device  600  can include a separate touch screen  607 . In some examples, touch screen  607  can be integrated with display  606 . Sensor stackup  609  can be located in active area  612  of device  600 . Active area  612  can be any area of device  600  configured to allow light emitted from display  606  to pass through and/or allow a touch and/or hover object to be detected by touch screen  607 . Instead of placing the sensor underneath (or on top of) display  606  and/or touch screen  607  or incorporating the sensor into the structure of display  606  and/or touch screen  607 , sensor stackup  609  can be integrated into cover material  614  and/or housing  616 . In some samples, sensor stackup  609  can disposed on cover material  614 . In some examples, sensor stackup  609  can be contacting cover material  614 . In some examples, sensor stackup  609  may not be separately packaged and/or fabricated. Sensor stackup  509  can include one or more layers that form the photodiode such as the P and N layers in a PN photodiode. In some examples, sensor stackup  609  can exclude a separate substrate (i.e., a base layer upon which a material is deposited onto). In some examples, one or more layers, excluding air, can be included in the sensor stackup  609  and can be located between cover material  614  and photodiode stackup  609 . In some examples, the one or more layers, excluding air, can contact cover material  614 . The one or more layers can include, but are not limited to, silicon dioxide and titanium dioxide. In this manner, sensor stackup  609  can be included in device  600  without the need for extra layers (e.g., a separate substrate), and measurement accuracy can be improved by having sensor stackup  609  located closer to the light source (e.g., ambient light). 
       FIG.  7    illustrates an exemplary block diagram of a computing system comprising light emitters and light sensors for measuring a signal associated with a user&#39;s physiological state according to examples of the disclosure. Computing system  700  can correspond to any of the computing devices illustrated in  FIGS.  1 A- 1 C . Computing system  700  can include a processor  710  configured to execute instructions and to carry out operations associated with computing system  700 . For example, using instructions retrieved from memory, processor  710  can control the reception and manipulation of input and output data between components of computing system  700 . Processor  710  can be a single-chip processor or can be implemented with multiple components. 
     In some examples, processor  710  together with an operating system can operate to execute computer code and produce and use data. The computer code and data can reside within a program storage block  702  that can be operatively coupled to processor  710 . Program storage block  702  can generally provide a place to hold data that is being used by computing system  700 . Program storage block  702  can be any non-transitory computer-readable storage medium, and can store, for example, history and/or pattern data relating to PPG signal and perfusion index values measured by one or more light sensors such as light sensors  704 . By way of example, program storage block  702  can include Read-Only Memory (ROM)  718 , Random-Access Memory (RAM)  722 , hard disk drive  708  and/or the like. The computer code and data could also reside on a removable storage medium and loaded or installed onto the computing system  700  when needed. Removable storage mediums include, for example, CD-ROM, DVD-ROM, Universal Serial Bus (USB), Secure Digital (SD), Compact Flash (CF), Memory Stick, Multi-Media Card (MMC) and a network component. 
     Computing system  700  can also include an input/output (I/O) controller  712  that can be operatively coupled to processor  710 , or it can be a separate component as shown. I/O controller  712  can be configured to control interactions with one or more I/O devices. I/O controller  712  can operate by exchanging data between processor  710  and the I/O devices that desire to communicate with processor  710 . The I/O devices and I/O controller  712  can communicate through a data link. The data link can be a one-way link or a two-way link. In some cases, I/O devices can be connected to I/O controller  712  through wireless connections. By way of example, a data link can correspond to PS/2, USB, Firewire, IR, RF, Bluetooth or the like. 
     Computing system  700  can include a display device  724  that can be operatively coupled to processor  710 . Display device  724  can be a separate component (peripheral device) or can be integrated with processor  710  and program storage block  702  to form a desktop computer (e.g., all-in-one machine), a laptop, handheld or tablet computing device of the like. Display device  724  can be configured to display a graphical user interface (GUI) including perhaps a pointer or cursor as well as other information to the user. By way of example, display device  724  can be any type of display including a liquid crystal display (LCD), an electroluminescent display (ELD), a field emission display (FED), a light emitting diode display (LED), an organic light emitting diode display (OLED), or the like. 
     Display device  724  can be coupled to display controller  726  that can be coupled to processor  710 . Processor  710  can send raw data to display controller  726 , and display controller  726  can send signals to display device  724 . Data can include voltage levels for a plurality of pixels in display device  724  to project an image. In some examples, processor  710  can be configured to process the raw data. 
     Computing system  700  can also include a touch screen  730  that can be operatively coupled to processor  710 . Touch screen  730  can be a combination of sensing device  732  and display device  724 , where the sensing device  732  can be a transparent panel that is positioned in front of display device  724  or integrated with display device  724 . In some cases, touch screen  730  can recognize touches and the position and magnitude of touches on its surface. Touch screen  730  can report the touches to processor  710 , and processor  710  can interpret the touches in accordance with its programming. For example, processor  710  can perform tap and event gesture parsing and can initiate a wake of the device or powering on one or more components in accordance with a particular touch. 
     Touch screen  730  can be coupled to a touch controller  740  that can acquire data from touch screen  730  and can supply the acquired data to processor  710 . In some cases, touch controller  740  can be configured to send raw data to processor  710 , and processor  710  can process the raw data. For example, processor  710  can receive data from touch controller  740  and can determine how to interpret the data. The data can include the coordinates of a touch as well as pressure exerted. In some examples, touch controller  740  can be configured to process raw data itself. That is, touch controller  740  can read signals from sensing points  734  located on sensing device  732  and can turn the signals into data that the processor  710  can understand. 
     Touch controller  742  can include one or more microcontrollers, each of which can monitor one or more sensing points  734 . The microcontroller can, for example, correspond to an application specific integrated circuit (ASIC), which works with firmware to monitor the signals from sensing device  732 , process the monitored signals, and report this information to processor  710 . 
     One or both of display controller  726  and touch controller  740  can perform filtering and/or conversion processes. Filtering processes can be implemented to reduce a busy data stream to prevent processor  710  from being overloaded with redundant or non-essential data. The conversion processes can be implemented to adjust the raw data before sending or reporting them to processor  710 . 
     In some examples, sensing device  732  can be based on capacitance. When two electrically conductive members come close to one another without actually touching, their electric fields can interact to form a capacitance. The first electrically conductive member can be one or more of the sensing points  734 , and the second electrically conductive member can be an object  790  such as a finger. As object  790  approaches the surface of touch screen  730 , a capacitance can form between object  790  and one or more sensing points  734  in close proximity to object  790 . By detecting changes in capacitance at each of the sensing points  734  and noting the position of sensing points  734 , touch controller  740  can recognize multiple objects, and determine the location, pressure, direction, speed and acceleration of object  790  as it moves across the touch screen  730 . For example, touch controller  790  can determine whether the sensed touch is a finger, tap, or an object covering the surface. 
     Sensing device  732  can be based on self-capacitance or mutual capacitance. In self-capacitance, each of the sensing points  734  can be provided by an individually charged electrode. As object  790  approaches the surface of the touch screen  730 , the object can capacitively couple to those electrodes in close proximity to object  790 , thereby stealing charge away from the electrodes. The amount of charge in each of the electrodes can be measured by the touch controller  740  to determine the position of one or more objects when they touch or hover over the touch screen  730 . In mutual capacitance, sensing device  732  can include a two layer grid of spatially separated lines or wires (not shown), although other configurations are possible. The upper layer can include lines in rows, while the lower layer can include lines in columns (e.g., orthogonal). Sensing points  734  can be provided at the intersections of the rows and columns. During operation, the rows can be charged, and the charge can capacitively couple from the rows to the columns. As object  790  approaches the surface of the touch screen  730 , object  790  can capacitively couple to the rows in close proximity to object  790 , thereby reducing the charge coupling between the rows and columns. The amount of charge in each of the columns can be measured by touch controller  740  to determine the position of multiple objects when they touch the touch screen  730 . 
     Device  700  can also include one or more light emitters, such as light emitters  706 , and one or more light sensors, such as integrated photodiodes  704 , located proximate to skin  720  of a user. Light emitters  706  can be configured to generate light, and light sensors  704  can be configured to measure a light reflected or absorbed by skin  720 , vasculature, and/or blood of the user. Light sensor  704  can send measured raw data to processor  710 , and processor  710  can perform noise and/or artifact cancellation to determine the PPG signal and/or perfusion index. In some examples, processor  710  can store the raw data and/or processed information in a ROM  718  or RAM  722  for historical tracking or for future diagnostic purposes. 
     An electronic device is disclosed. The electronic device can comprise: one or more light sensors configured to detect a reflection of a light and configured to generate a signal indicative of the light, wherein the one or more light sensors includes a plurality of layers; one or more windows capable of allowing the light to pass through and configured to support the one or more light sensors; and a back surface coupled to the one or more windows, wherein at least one of the plurality of layers contacts one or more of the back surface and at least one of the one or more windows. Additionally or alternatively, in some examples, a gap between the one or more windows and a stackup included in the one or more light sensors is less than 0.8 mm. Additionally or alternatively, in some examples, a surface of the stackup contacts a surface of the one or more windows. Additionally or alternatively, in some examples, the stackup includes a p-type material, and the p-type material contacts a surface of the one or more windows. Additionally or alternatively, in some examples, the device further comprises: one or more layers located between the one or more windows and the one or more light sensors, wherein a surface of the one or more layers contacts the one or more windows and another surface of the one or more layers contacts the one or more light sensors, the one or more layers excluding air. Additionally or alternatively, in some examples, the electronic device excludes a separate substrate supporting the one or more light sensors. Additionally or alternatively, in some examples, the one or more light sensors are disposed on a surface of the one or more windows, the surface is opposite from an outer surface of the electronic device, and an active area of the one or more light sensors faces towards the outer surface of the electronic device. Additionally or alternatively, in some examples, the device further comprises: a plurality of conductive pads; and a plurality of routing traces, each routing trace coupled to one of the one or more light emitters or the one or more light sensors and configured to route one or more signals between at least one of the one or more light emitters or the one or more light sensors and at least one of the plurality of conductive pads, wherein the plurality of routing traces and the plurality of conductive pads are disposed a surface of the back surface, the surface of the back surface located away from an outer surface of the electronic device. Additionally or alternatively, in some examples, the device further comprises: a plurality of conductive pads; a plurality of vias; a plurality of first routing traces, each first routing trace coupled to one of the one or more light emitters or the one or more light sensors and configured to route one or more signals between at least one of the one or more light emitters or the one or more light sensors and at least one of the plurality of vias; and a plurality of second routing traces, each second routing trace coupled to at least one of the plurality of vias and configured to route one or more signals between the at least one of the plurality of vias and at a least one of the plurality of conductive pads. Additionally or alternatively, in some examples, the device further comprises: one or more conductive pads configured to route one or more signals to at least one of the one or more light emitters or at least one of the one or more light sensors, wherein the one or more conductive pads are located in an outer perimeter of the back surface. Additionally or alternatively, in some examples, the one or more light sensors are disposed on an outer surface of the electronic device. Additionally or alternatively, in some examples, the device further comprises: a coating contacting the one or more light sensors and configured to protect the one or more light sensors, wherein the one or more light sensors are located between the coating and the back surface. Additionally or alternatively, in some examples, the coating includes a black ink. Additionally or alternatively, in some examples, at least one of the one or more light sensors is a black photodiode. Additionally or alternatively, in some examples, a surface of a stackup included in the one or more light sensors contacts the back surface. Additionally or alternatively, in some examples, the surface is opposite from an inner surface of the electronic device and an active area of the one or more light sensors faces towards an outer surface of the electronic device. Additionally or alternatively, in some examples, the one or more light sensors includes at least two light sensors, wherein a total active area of the at least two light sensors substantially occupies a full area of the back surface. Additionally or alternatively, in some examples, the device further comprises: an isolation located between the at least two light sensors and configured to electrically isolate the at least two light sensors. Additionally or alternatively, in some examples, the at least two light sensors are spatially separated by at least 5 microns. 
     A method for detecting physiological signals is disclosed. The method comprises: emitting light from one or more light emitters to one or more windows without first transmitting through a layer of air; allowing light to pass through the one or more windows; detecting the light from tissue; and generating one or more signals indicative of the reflection of light. Additionally or alternatively, in some examples, emitting light from the one or more light emitters to the one or more windows comprises: emitting light from the one or more light emitters to a coating, and allow light to pass through the coating to the one or more windows. Additionally or alternatively, in some examples, emitting light from the one or more light emitters to the one or more windows comprises: transmitting light through a sensor-window interface. Additionally or alternatively, in some examples, emitting light from the one or more light emitters to the one or more windows comprises: transmitting light through a layer-window interface, wherein the layer excludes air. 
     Although the disclosed examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosed examples as defined by the appended claims.

Metadata:
Filing Date: 20170811
Publication Date: 20230124
Grant Date: 20230124
Priority Date: 20160812
Inventors: MEHTA, ARPIT
SHAO, Guocheng
HARRISON-NOONAN, TOBIAS J.
Assignee: APPLE INC
CPC Classifications: [{"code": "A61B5/681", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6898", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B2562/046", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/02427", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B2562/0238", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2562/182", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2562/146", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2560/0462", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/681", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B5/14551", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/0295", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2560/0462", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/681", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6898", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B2562/0238", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/02427", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B2562/046", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2562/182", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2562/146", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 84977873