PATENT DOCUMENT

Publication Number: US-11337654-B2
Application Number: US-201916370031-A
Country: US
Kind Code: B2

Title: Sensing contact force related to user wearing an electronic device

Abstract:
A wearable electronic device includes a body, a housing component, a band operable to attach the body to a body part of a user, and a force sensor coupled to the housing component. The force sensor is operable to produce a force signal based on a force exerted between the body part of the user and the housing component. A processing unit of the wearable electronic device receives the force signal from the force sensor and determines the force exerted on the housing component based thereon. The processing unit may use that force to determine a tightness of the band, determine health information for the user, adjust determined force exerted on a cover glass, and/or to perform various other actions.

Claims:
What is claimed is: 
     
       1. A wearable electronic device, comprising:
 a body; 
 a cover glass coupled to the body; 
 a plate coupled to the body, the plate configured to be positioned adjacent to a portion of a user when the wearable electronic device is worn; 
 a first force sensor, coupled to the cover glass, that produces a first force signal using a first force exerted on the cover glass; 
 a second force sensor, coupled to the plate, that produces a second force signal based on a second force exerted between the portion of the user and the plate; and 
 a processing unit, communicably coupled to the first and second force sensors, that:
 determines a first amount of the first force based on the first force signal; 
 determines a second amount of the second force based on the second force signal; and 
 adjusts the first amount of the first force using the second force signal. 
 
 
     
     
       2. The wearable electronic device of  claim 1 , wherein the processing unit adjusts the second amount of the second force using the first force signal. 
     
     
       3. The wearable electronic device of  claim 1 , wherein the processing unit determines a pressure to which the body is exposed using the first force signal and the second force signal. 
     
     
       4. The wearable electronic device of  claim 3 , wherein the pressure is a hydrostatic pressure. 
     
     
       5. The wearable electronic device of  claim 1 , wherein the processing unit determines whether the wearable electronic device is worn by the user using the second force signal. 
     
     
       6. The wearable electronic device of  claim 1 , wherein the processing unit adjusts the first amount of the first force by subtracting the second force signal from the first force signal. 
     
     
       7. The wearable electronic device of  claim 1 , further comprising a band coupled to the body wherein the processing unit uses the second amount of the second force to determine a tightness of the band. 
     
     
       8. A wearable electronic device, comprising:
 a main watch housing; 
 a first force sensor; 
 a cover coupled to the main watch housing by the first force sensor; 
 a second force sensor; 
 a back plate coupled to the main watch housing by the second force sensor; and 
 a processing unit disposed in the main watch housing, communicably coupled to the first force sensor and the second force sensor, that:
 determines a first estimate of a first force exerted on the cover using the first force sensor; 
 determines a second estimate of a second force exerted on the back plate using the second force sensor; and 
 adjusts the first estimate of the first force using the second estimate of the second force. 
 
 
     
     
       9. The wearable electronic device of  claim 8 , wherein the first force sensor measures the first force at a same time that the second force sensor measures the second force. 
     
     
       10. The wearable electronic device of  claim 8 , wherein the cover is opposite the back plate. 
     
     
       11. The wearable electronic device of  claim 8 , wherein the main watch housing is positioned between the cover and the back plate. 
     
     
       12. The wearable electronic device of  claim 8 , wherein the processing unit interprets the first estimate of the first force as a user input. 
     
     
       13. The wearable electronic device of  claim 8 , wherein the second force sensor comprises a capacitive sensor. 
     
     
       14. The wearable electronic device of  claim 8 , wherein the second force sensor comprises a strain gauge. 
     
     
       15. A wearable electronic device, comprising:
 a cover; 
 a plate; 
 a main housing coupled between the cover and the plate such that the cover is opposite the plate; 
 a first force sensor disposed between the cover and the main housing; 
 a second force sensor disposed between the plate and the main housing wherein the plate is coupled to the main housing by the second force sensor; and 
 a processing unit disposed in the main housing, communicably coupled to the first force sensor and the second force sensor, that:
 determines a first force estimate using a first force on the cover measured using the first force sensor; 
 determines a second force estimate using a second force on the plate measured using the second force sensor; and 
 determines an input by subtracting the second force estimate from the first force estimate. 
 
 
     
     
       16. The wearable electronic device of  claim 15 , wherein the processing unit determines a user input using a third force estimate determined using a third force on the plate. 
     
     
       17. The wearable electronic device of  claim 15 , wherein the processing unit corrects the input for an inaccuracy in the first force estimate by subtracting the second force estimate from the first force estimate. 
     
     
       18. The wearable electronic device of  claim 17 , wherein the inaccuracy results from hydrostatic pressure. 
     
     
       19. The wearable electronic device of  claim 17 , wherein the inaccuracy results from atmospheric pressure. 
     
     
       20. The wearable electronic device of  claim 15 , wherein the first force and the second force are configured to be exerted by a body of a user.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a division of U.S. patent application Ser. No. 14/867,311, filed Sep. 28, 2015, entitled “Sensing Contact Force Related to User Wearing an Electronic Device,” the contents of which are incorporated herein by reference as if fully disclosed herein. 
    
    
     FIELD 
     The described embodiments relate generally to wearable electronic devices. More particularly, the present embodiments relate to sensing the force applied to a wearable electronic device by a user&#39;s body part when a user is wearing the wearable electronic device. 
     BACKGROUND 
     Users frequently encounter a variety of different electronic devices in the modern world. Such electronic devices include computers, media players, entertainment systems, displays, communication systems, and so on. Many electronic devices, such as laptop computers, tablet computers, and smart phones, may be portable. 
     Some electronic devices, referred to as “wearable electronic devices,” may be configured to be worn by a user. In some cases, such a wearable electronic device may include one or more bands, straps, or other attachment mechanisms that may be used to attach the wearable electronic device to a user&#39;s body part. For example, a wrist worn wearable electronic device may include a band that can be used to secure the wearable electronic device to a user&#39;s wrist. 
     Wearable electronic devices may include a variety of components. For example, wearable electronic devices may include input devices that a user can manipulate by touch. By way of another example, wearable electronic devices may include various sensors, such as sensors that may be used to detect information about the user. 
     SUMMARY 
     The present disclosure relates to wearable electronic devices that sense the force applied to the wearable electronic device by a user&#39;s body part when the user is wearing the wearable electronic device. The wearable electronic device may include a body, a housing component, and a band or other attachment mechanism operable to attach the body to the body part of a user. A force sensor may be positioned between the housing component and the body that produces force signals based on a force exerted between the user&#39;s body part and the housing component. A processing unit may receive the force signals and process them to perform various actions. 
     In various embodiments, a wearable electronic device includes a body, a housing component coupled to the body, a band operable to attach the body to a body part of a user, a force sensor coupled to the housing component that is operable to produce a force signal based on a force exerted between the body part of the user and the housing component, and a processing unit communicably coupled to the force sensor. The processing unit may be operable to determine a tightness of the band based on the force signal received from the force sensor. 
     In some examples, the force sensor may be a strain gauge mounted to a deflection element that is connected to the body and the housing component. In such an example, the force signal may indicate deflection of the deflection element based on strain data detected by the strain gauge. 
     In various examples, the force sensor may be a gasket positioned between the body of the wearable electronic device and the housing component. The gasket may include a pair of electrodes separated by a deformable material. In such an example, the force signal may indicate a capacitance between the pair of electrodes. The pair of electrodes may form a capacitor and the force signal may represent a capacitance of the capacitor. 
     In one or more examples, the force sensor may include an electrode. In such an example, the force signal may indicate a capacitance between the electrode and the body part of the user. The electrode and the body part of the user may form a capacitor and the force signal may represent a capacitance of the capacitor. The electrode may be coupled to one of the housing component, the body, or a circuit board coupled to the body. In some embodiments, the electrode may be formed of indium tin oxide, nanostructures, nanomesh, nanowires, a conductive film, and so on. 
     In some examples, the wearable electronic device may further include a circuit board coupled to the body, and the force sensor may include a first electrode coupled to the housing component and a second electrode coupled to the circuit board. In such an example, the force signal received from the first and second electrodes may indicate a capacitance between the first electrode and the second electrode. In various cases of such an example, the first electrode may be a first set of electrodes and the second electrode may be a second set of electrodes. In some cases of this example the housing component may be flexible. 
     In some embodiments, a wearable electronic device may include a body, a surface component coupled to the body, a health sensor coupled to the body, a force sensor coupled to the surface component, and a processing unit communicably coupled to the force sensor. The surface component may be positioned adjacent to a body part of a user when the wearable electronic device is worn. The health sensor may be operable to obtain a measurement of the body part of the user. The force sensor may be operable to produce a force signal based on a force exerted between the body part of the user and the surface component. The processing unit may be operable to determine health information for the user based on the force signal received from the force sensor and the measurement obtained by the health sensor. 
     In one or more examples, the health information may include at least one of a swelling indication, a blood pressure, a body fat indication, an allergic reaction indication, a hydration indication, or an edema indication. 
     In various examples, the processing unit may determine whether the measurement obtained by the health sensor is accurate based on the force signal. 
     In some examples, the wearable electronic device may include a band operable to attach the body to the body part of the user. In such examples, the processing unit may determine a tightness of the band based on the force signal. If the tightness of the band is within a range of force values, the processing unit may determine the measurement obtained by the health sensor is accurate. If the tightness of the band is outside the range of force values, the processing unit may determine the measurement obtained by the health sensor is inaccurate. 
     In various examples, the wearable electronic device may further include a band operable to attach the body to the body part of the user and a band tightness adjustment mechanism. In such an example, the processing unit may determine a tightness of the band based on the force signal received from the force sensor and cause the tightness of the band to be altered using the band tightness adjustment mechanism. In various cases, the processing unit may provide a notification to the user by causing the tightness of the band to be altered. 
     In one or more embodiments, a wearable electronic device may include a body, a cover glass coupled to the body, a plate coupled to the body, a first force sensor coupled to the cover glass, a second force sensor coupled to the plate, and a processing unit communicably coupled to the first and second force sensors. The plate may be positioned adjacent to a body part of a user when the wearable electronic device is worn. The first force sensor may be operable to produce a first force signal based on a first force exerted on the cover glass. The second force sensor may be operable to produce a second force signal based on a second force exerted between the body part of the user and the plate. The processing unit may be operable to determine an amount of the first force based on the first force signal, determine an amount of the second force based on the second force signal, and adjust the amount of the first force based on the second force signal. 
     In various examples, the processing unit may be further operable to adjust the amount of the second force based on the first force signal. For example, the first force exerted on the cover glass may cause additional force to be exerted between the body part of the user and the plate. In order to determine the second force exerted between the body part of the user and the plate without the additional force being exerted due to the first force exerted on the cover glass, the amount of the second force may be adjusted based on the first force signal to remove the influence of the first force. 
     In some examples, the processing unit may be further operable to determine a pressure to which the body is exposed based on the first force signal received from the first force sensor and the second force signal received from the second force sensor, such as a water pressure. 
     In one or more examples, the processing unit may determine whether the wearable electronic device is worn by the user based on the second force signal received from the second force sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1A  shows a wearable electronic device that may sense the force exerted by a body part of a user on the wearable electronic device when the user is wearing the wearable electronic device. 
         FIG. 1B  shows the wearable electronic device of  FIG. 1A  from the back with the band opened. 
         FIG. 2A  shows an example cross-sectional view of the wearable electronic device of  FIG. 1B , taken along line A-A of  FIG. 1B . 
         FIG. 2B  shows the wearable electronic device of  FIG. 2A  on a user&#39;s body part. 
         FIG. 2C  shows the wearable electronic device of  FIG. 2B  after tightening of the band. 
         FIGS. 3-7  show additional examples of the wearable electronic device of  FIG. 2A  in accordance with further embodiments. 
         FIG. 8  shows a flow chart illustrating an example method for determining band tightness. This method may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
         FIG. 9  shows a flow chart illustrating an example method for determining health information using a health sensor and a force sensor. This method may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
         FIG. 10  shows a flow chart illustrating an example method for adjusting detected force determinations. This method may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
         FIG. 11  shows a block diagram illustrating example components that may be utilized in the wearable electronic device and example functional relationships of those components. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The description that follows includes sample systems, methods, and apparatuses that embody various elements of the present disclosure. However, it should be understood that the described disclosure may be practiced in a variety of forms in addition to those described herein. 
     The following disclosure relates to wearable electronic devices operable to sense the force applied to the wearable electronic device by body part of a user when the user is wearing the wearable electronic device. The wearable electronic device may include a body, a housing component (such as a plate, a curved plate, or other surface component), and a band or other attachment mechanism operable to attach the body to the body part of a user. A force sensor may be positioned between the housing component and the body such that it produces force signals based on a force exerted between the user&#39;s body part and the housing component. A processing unit may receive the force signals and process them to perform various actions. 
     For example, the processing unit may process the force signals to determine a tightness of the band, such as for automatic band adjustment. By way of another example, the processing unit may use the force signals to determine health information for the user, such as in combination with measurements of the body part obtained via a health sensor included in the body. By way of still another example, the body may include an input mechanism (such as a touch surface including a cover glass) that interprets the force of a user&#39;s touch as input and the processing unit may use the force signals and signals from the input mechanism to adjust determinations of force applied to the housing component or input mechanism. Various uses for the force signals from the force sensor are possible and contemplated. 
     These and other embodiments are discussed below with reference to  FIGS. 1A-11 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1A  shows a wearable electronic device  100  that may sense the force applied to the wearable electronic device  100  when the user is wearing the wearable electronic device  100 .  FIG. 1B  shows the wearable electronic device  100  of  FIG. 1A  from the back with the band  102  opened. 
     With reference to  FIGS. 1A and 1B , the wearable electronic device  100  may include a main body  101  that is operable to be coupled to the body part of a user (such as a wrist) via the band  102  or other attachment mechanism. For example, the band  102  may be operable to attach to the main body  101  and to the body part of the user, thus attaching the main body  101  to the body part of the user. A housing component  104  (such as a plate, a curved plate, or other surface component) may be coupled to the main body  101  in such a way that the wearable electronic device  100  may determine the amount of force exerted by the user&#39;s body part contacting the housing component  104  when the band  102  is attached to user. The wearable electronic device  100  may utilize the determined force in a variety of ways that will be discussed in detail below. 
     The housing component  104  may be a sensor plate associate with a sensor of the main body  101 . As such, the housing component  104  may include one or more sensor windows  105  associated with the operation of that sensor. 
     The band  102  may include a first band portion  103 A and a second band portion  103 B. The second band portion  103 B may include a band tightening mechanism  106  that is operable to tighten the band  102  around the user&#39;s body part. However, it is understood that this is an example. In various implementations, the first band portion  103 A may include such a tightening mechanism instead of and/or in addition to the second band portion  103 B. Further, in some implementations, the band  102  may not have separate portions and/or may have more than two portions without departing from the scope of the present disclosure. 
       FIG. 2A  shows an example cross-sectional view of the wearable electronic device  100  of  FIG. 1B , taken along line A-A of  FIG. 1B . The housing component  104  may be coupled to the main body  101  via a housing component force sensor  210  (such as via one or more adhesives, springs, and/or other attachment mechanisms). The housing component force sensor  210  may include one or more first electrodes  211  separated from one or more second electrodes  213  by a deformable material  212  (such as silicone, an air gap, and so on). For example, the first and second electrodes  211  and  213  may be discrete electrodes or sets of electrodes. The first and second electrodes  211  and  213  may be included in a flexible circuit layer. The first and second electrodes  211  and  213  may be aligned to form a capacitor. Force exerted on the housing component  104  may deform the deformable material  212 , changing the proximity of the first and second electrodes  211  and  213  and thus a capacitance of a capacitor formed by the first and second electrodes  211  and  213  (e.g., the capacitance between the first and second electrodes  211  and  213 ). The housing component force sensor  210  may generate force signals that represent the changes in capacitance. 
     A processing unit  218  may be disposed within the main body  101 . In this example, the processing unit  218  may be disposed on a printed circuit board  216  mounted within the body such as via one or more adhesives and/or other attachment mechanisms. The printed circuit board  216 , and thus the processing unit  218 , may be connected to the housing component force sensor  210  via a flex circuit  214  (and/or other electrical or communication connection). The processing unit  218  may receive the force signal generated by the housing component force sensor  210  via the flex circuit  214  and the printed circuit board  216 . The processing unit  218  may associate various exerted force values with various capacitance changes. As such, the processing unit  218  may analyze the force signal to determine the force exerted on the housing component  104 . 
     The force determined by the processing unit  218  by analyzing force signals may be a non-binary value. The processing unit  218  may analyze the force signals to determine forces across a range of force values as opposed to detecting that a threshold amount of force is exerted. The processing unit  218  may analyze force signals to correlate data in the force signals to an amount of force applied out of a range of possible forces. 
     The processing unit  218  may utilize the determined force exerted on the housing component  104  for a variety of purposes. Examples that will be discussed in further detail below include determining a tightness of the band  102  (such as for automatic band adjustment, signaling a user to adjust, and so on), determining whether or not the wearable electronic device  100  is being worn, and obtaining user input (such as wrist movement gestures and so on), determining health information (using the determined force alone and/or in combination with measurements from a health sensor and/or other data). Additionally or alternatively, the processing unit  218  may utilize the determined force exerted on the housing component  104  in combination with force determined based on signals from another force sensor (such as to adjust one or both of the determined forces, to determine pressure based on both determined forces, and so on). However, it is understood that these are examples and that the processing unit  218  may utilize the determined force exerted on the housing component  104  for a variety of other purposes (such as in combination with data from one or more accelerometers, gyroscopes, altimeters, and so on) without departing from the scope of the present disclosure. 
     In some embodiments, the housing component force sensor  210  may function as a gasket, positioned in a perimeter between the main body  101  and the housing component  104 , and forming a seal between the main body  101  and the housing component  104 . Further, although the housing component force sensor  210  is described as a single force sensor, it is understood that this is an example. In various implementations, multiple housing component force sensors  210  may be positioned in a perimeter between the main body  101  and the housing component  104 . The multiple housing component force sensors  210  may be part of a gasket or other structure that includes the housing component force sensors  210  with the deformable material  212  and/or other materials filling gaps in between the housing component force sensors  210 . In such an implementation, the processing unit  218  may analyze and compare force signals from each housing component force sensor  210  to determine one or more forces exerted on the housing component  104  in various directions, at various positions, and so on. 
     As discussed above, the tightness of the band  102  may be determined by the processing unit  218  using the determined force exerted on the housing component  104 .  FIG. 2B  shows the wearable electronic device  100  of  FIG. 2A  on a user&#39;s body part  230  (depicted as the user&#39;s wrist, though this is merely an example and any body part may be used in other implementations). The user&#39;s body part  230  may exert force on the housing component  104 . The force exerted by the user&#39;s body part  230  on the housing component  104  may be proportional to the tightness of the band  102 . In other words, the tighter the band  102 , the more force exerted by the user&#39;s body part  230  on the housing component  104 . Similarly, the looser the band  102 , the less force exerted by the user&#39;s body part  230  on the housing component  104 . 
     The tightness of the band  102  may be significant for user comfort, ensuring the wearable electronic device  100  stays attached, and so on. As such, the tightness of the band  102  may be monitored for user comfort based on default tightness settings, user specified comfort settings, and so on. If the band  102  is too tight or too loose, the processing unit  218  may provide output instructing the user to adjust the band  102 , automatically adjust the band  102  using a mechanism such as the band tightening mechanism  106  discussed below, and/or perform other such actions. 
     The tightness of the band  102  may be significant for reasons other than comfort. In various implementations, the wearable electronic device  100  may include one or more sensors and/or other components whose operation may depend on tightness of the band  102 . In such implementations, the processing unit  218  may provide adjustment instructions and/or adjust the band  102  to improve operation of such sensors and/or other components. 
     For example, a health sensor  215  may be coupled to the housing component  104 . In one embodiment, the health sensor  215  may be a photoplethysmogram (PPG) sensor that emits light through the sensor windows  105  into the user&#39;s body part  230  and receives the portion of the transmitted light that is reflected back from the user&#39;s body part  230 . The health sensor  215  may be coupled to the processing unit  218  via the printed circuit board  216  and a flex circuit  217  (and/or other electrical or communication connection) and may transmit measurements regarding the received light to the processing unit  218 . The operation of the health sensor  215  may be affected by the tightness of the band  102 . For example, the health sensor  215  may transmit less accurate measurements if the band  102  is too loose. As such, the processing unit  218  may provide adjustment instructions and/or tighten the band  102  to improve operation of the health sensor  215 . 
       FIG. 2C  shows the wearable electronic device  100  of  FIG. 2B  after tightening of the band  102  by the band tightening mechanism  106  as controlled by the processing unit  218 . In this example, the second band portion  103 B may be divided into sections separated by a gap  226 . The sections may be connected to a winch mechanism  228  by cords  229  (and/or wires or other joining mechanisms). The winch mechanism  228  may be controlled by a motor  227 , which may be connected to the printed circuit board  216 , and thus the processing unit  218 , via a flex circuit  225  (and/or other electrical or communication connection). Thus, the processing unit  218  may control the winch mechanism  228  to roll and/or unroll the cords  229  to bring the sections closer and narrow the gap  226  (see  FIG. 2C ) and/or to allow the sections to move further apart and expand the gap  226  (See  FIG. 2B ). 
     However, it is understood that the band tightening mechanism  106  is an example. Other band tightening mechanisms  106  constructed from various different components functioning under various different principles of operation can be used without departing from the scope of the present disclosure. For example, in some implementations, a memory wire such as Nitinol may be embedded in the band  102 . The processing unit  218  may cause current to be provided to such a memory wire in order to change the shape of the memory wire, thus adjusting the tightness of the band  102 . 
     Moreover, as discussed above, the processing unit  218  may utilize the determined force exerted on the housing component  104  to determine whether or not the wearable electronic device  100  is currently being worn. In various implementations, the processing unit  218  may operate in different states depending on whether or not the wearable electronic device  100  is currently worn (such as an active state if worn and a sleep or lower power state if unworn). In such implementations, the processing unit  218  may determine that the wearable electronic device  100  is worn if the determined force exerted on the housing component  104  is above a threshold force value and that the wearable electronic device  100  is unworn if the determined force exerted on the housing component  104  is below the threshold force value. 
     As also discussed above, the processing unit  218  may utilize the determined force exerted on the housing component  104  to obtain user input. For example, different movements of the user&#39;s body part  230  (such as bending of the wrist, flexing of the wrist, and so on) may exert different forces on the housing component  104 . The processing unit  218  may analyze the determined force in order to determine how the user&#39;s body part  230  has moved. These different movements may be interpreted as gestures that are associated with different inputs. As such, the user may provide particular input to the processing unit  218  by making particular movements. For example, bending of the user&#39;s body part  230  may indicate to the processing unit  218  that the user wants to wake the wearable electronic device  100  from a sleep and/or otherwise low power state. 
     As further discussed above, the processing unit  218  may utilize the determined force exerted on the housing component  104  to determining health information. In some examples, the processing unit  218  may utilize the determined force by itself to determine health information. In other examples, the processing unit  218  may utilize the determined force in combination with measurements from a health sensor  215  and/or data from other sensors or devices (such as a camera, an accelerometer, and so on). 
     In some implementations, the processing unit  218  may determine a tightness of the band  102  based on the determined force over time. This determined tightness over time may be used to determine size changes in the user&#39;s body part  230  over time. Using such data, the processing unit  218  may be able to determine and/or detect an indication of a user&#39;s body fat, an indication of blood pressure, an indication of a pulse rate, an indication of swelling (such as caused by an allergic reaction, perhaps to a material used in the wearable electronic device  100 ), an indication of an allergic reaction, an indication of hydration (such as by relaxation of swelling over time), an indication of conditions such as edema or cutaneous edema, and so on. In various implementations, the processing unit  218  may utilize the determined tightness in combination with measurements by the health sensor  215 , such as a PPG sensor, to determine health information of the user such as blood perfusion. 
     In still other implementations, the processing unit  218  may receive measurements from the health sensor  215 . However, as described earlier, the measurements transmitted by the health sensor  215  may be inaccurate or less accurate if the band  102  is too loose or too tight. As such, the processing unit  218  may disregard measurements from the health sensor  215  if the determined force exerted on the housing component  104  indicates the band  102  is too loose or too tight. 
     Alternatively, the processing unit  218  may attempt to obtain a replacement measurement from the health sensor  215  if the determined force exerted on the housing component  104  indicates the band  102  is too loose or too tight. In such an example, measurements may be discarded if obtained from the health sensor  215  when the determined force exerted on the housing component  104  indicates the band  102  is too loose or too tight. In various implementations, the processing unit  218  may attempt to correct possible inaccuracies in the measurement. 
     As additionally discussed above, the processing unit  218  may utilize the determined force exerted on the housing component  104  in combination with force signals from another force sensor and/or data from other components. In various examples, the processing unit  218  may adjust the force determined from the other force sensor, adjust the determined force exerted on the housing component  104  based on the force determined from the other force sensor, determine pressure based on both determined forces, and so on. 
     For example, the wearable electronic device  100  may include an input device that interprets exerted force as input. As shown in  FIGS. 2A-2C , the main body  101  may include a cover glass  224  (which may be part of a display such as a touch display) coupled to the main body  101 . The cover glass  224  may be coupled to a cover glass force sensor  220  (such as via one or more adhesives or other attachment mechanisms). The cover glass force sensor  220  may include one or more first electrodes  221  separated from one or more second electrodes  223  by a deformable material  222  (such as silicone, an air gap, and so on). The first and electrodes  221  and  223  may form a capacitor. Force exerted on the cover glass  224  may deform the deformable material  222 , changing a capacitance of the capacitor. The cover glass force sensor  220  may generate force signals indicating such changes in capacitance. 
     The cover glass force sensor  220  may be coupled to the printed circuit board  216 , and thus the processing unit  218 , via a flex circuit  219  (and/or other electrical or communication connection). The processing unit  218  may receive the force signals generated by the cover glass force sensor  220  via the flex circuit  219  and the printed circuit board  216 . The processing unit  218  may associate various exerted force values with various capacitance changes. As such, the processing unit  218  may analyze the force signal to determine the amount of force exerted on the cover glass  224 . 
     The processing unit  218  may evaluate both the first force signals generated by the housing component force sensor  210  corresponding to the force exerted on the housing component  104  and the second force signals generated by the cover glass force sensor  220  corresponding to the force exerted on the cover glass  224 . In some implementations, the processing unit  218  may utilize one of the force signals to adjust the other of the force signals. 
     For example, a force exerted by a user on the cover glass  224  while the wearable electronic device  100  is worn may be different from a force applied while the wearable electronic device  100  is unworn. This may be because the wearable electronic device  100  is being pressed between the exertion of force on the cover glass  224  and the force between the user&#39;s body part  230  and the wearable electronic device  100  when the wearable electronic device  100  is worn. Conversely, force exerted on the cover glass  224  is not opposed by force between the user&#39;s body part  230  and the wearable electronic device  100  when the wearable electronic device  100  is unworn. Thus, the same amount of force exerted on the cover glass  224  could be determined to be different depending on whether or not the wearable electronic device  100  is worn at the time. 
     Therefore the processing unit  218  may modify the force detected on the cover glass  224  by any force detected on the housing component  104  in order for the processing unit  218  to determine force exerted on the cover glass  224  more uniformly regardless whether the wearable electronic device  100  is worn or not. For example, the force detected on the housing component  104  may be subtracted from the force detected on the cover glass  224 . By way of another example, a modifier may be added to the force detected on the cover glass  224  when force is not detected on the housing component  104 . Such a modifier may correspond to the force normally detected on the housing component  104  when the wearable electronic device  100  is worn. 
     By way of another example, if only the force exerted on the housing component  104  is used to determine the tightness of the band  102  while a user is exerting a force on the cover glass  224 , the processing unit  218  may determine that the band  102  is tighter than it really is. This is because the force exerted on the cover glass  224  also exerts force on the housing component force sensor  210 . To determine a more accurate tightness of the band  102 , the processing unit  218  may subtract the force exerted on the cover glass  224  from the force exerted on the housing component  104  (and/or otherwise modify the determined force exerted on the housing component  104  based on the force exerted on the cover glass  224 ). 
     In other implementations, the processing unit  218  may use both forces in combination. For example, if force is exerted on both the housing component  104  and the cover glass  224  in relatively equal amounts, the processing unit  218  may determine that the forces are due to pressure as opposed to a user exerting force. The processing unit  218  may then evaluate the forces to determine a pressure to which the wearable electronic device  100  is subjected. 
     In some examples, the pressure may be hydrostatic pressure or water pressure, such as where the wearable electronic device  100  is submerged in water and/or other liquid. In such an example, the processing unit  218  may associate the forces detected with particular hydrostatic pressures in order to determine a depth of liquid in which the wearable electronic device  100  is immersed. 
     Although a particular configuration of the housing component  104 , the main body  101 , and the housing component force sensor  210  are shown and described, it is understood that this is an example. In other implementations, various configurations of the same, similar, and/or different components may be utilized without departing from the scope of the present disclosure. For example,  FIGS. 3-7  show additional examples of the wearable electronic device  100  of  FIG. 2A  in accordance with further embodiments. 
       FIG. 3  illustrates an example implementation including a deflection element  331  coupled to one or more strain gauges  332 . The deflection element  331  may be connected to the health sensor  315  and/or the housing component  304  such that force exerted on the housing component  304  may cause the deflection element  331  to deflect. An electrical property of the strain gauge  332  (e.g., resistance) may change based on the deflection. The processing unit  318  may accordingly receive force signals from the strain gauge  332  via a flex circuit  333  (and/or other electrical or communication connection) and the printed circuit board  316 , and may correlate the force signals to an amount of force. 
     The housing component  304  may be coupled to the main body  301  via adhesive  334 . The deflection element  331  may be positioned within the adhesive  334  between the housing component  304  and the main body  301 . In some examples, the adhesive  334  may be flexible such that the housing component  304  is operable to move with respect to the main body  301  under the exertion of force to deflect the deflection element  331 . In other examples, the adhesive  334  may form a rigid seal and the housing component  304  may be flexible in order to deflect the deflection element  331  under the exertion of force. 
       FIG. 4  illustrates an example implementation including a single electrode  435  formed of indium tin oxide or other material positioned on the printed circuit board  416 . The single electrode  435  may form a capacitor with the user&#39;s body part. Force exerted by the user&#39;s body part on the housing component  404  may change the proximity between the user&#39;s body part and the electrode  435  thus changing the capacitance of a capacitor formed by the user&#39;s body and the electrode  435 . The processing unit  418  may receive force signals from such a capacitor indicating capacitive changes and correlate the capacitive changes to an amount of force exerted on the housing component  404 . 
     In some examples, the adhesive  434  and/or the housing component  404  may be flexible. This may allow the user&#39;s body to move closer to the electrode  435  under the exertion of force. The more movement that is possible between the user&#39;s body and the electrode  435  may allow for a greater variety of capacitance differences of a capacitor formed by the user&#39;s body and the electrode  435 , allowing for greater sensitivity in sensing force. 
     Although the electrode  435  is shown as positioned on the printed circuit board  416 , it is understood that this is an example. In various implementations, the electrode  435  may be positioned at different locations without departing from the scope of the present disclosure. For example, the electrode  435  may be positioned on the health sensor  415  in some implementations. By way of another example, in various implementations, the electrode  435  may be positioned on the housing component  404  (such as a layer of indium tin oxide, nanostructures, nanomesh, nanowires, a conductive film, and so on deposited on the inner surface of the housing component  404  facing the health sensor  415 ) or on the main body  401 . 
       FIG. 5  illustrates an example implementation including a first electrode  536  positioned on the printed circuit board  516  and a second electrode  537  positioned on the housing component  504  that may form a capacitor. An exertion of force on the housing component  504  may bring the first and second electrodes  536  and  537  closer together, changing the capacitance of a capacitor formed by the first and second electrodes  536  and  537 . The processing unit  518  may monitor force signals from the first and/or second electrodes  536  and  537  and correlate the capacitance changes to an amount of force exerted on the housing component  504 . 
     In some examples, the adhesive  534  and/or the housing component  504  may be flexible. This may allow the first and second electrodes  536  and  537  to move closer together under the exertion of force on the housing component  504 . 
     As compared with the example shown in  FIG. 5 , the example depicted in  FIG. 6  includes multiple electrodes  637  (a first set of electrodes  637 ) positioned on the printed circuit board  616  and multiple electrodes  638  (a second set of electrodes  638 ) positioned on the housing component  604 . Capacitors may be formed by pairs of electrodes of the first set of electrodes  637  and the second set of electrodes  638 . A force applied to the housing component  604  may bring one or more electrodes in the first and second sets of electrodes  637  and  638  closer together, and change the respective capacitances of those capacitors. The processing unit  618  may monitor and compare force signals from one or more capacitors in order to correlate respective capacitance changes to amounts of force exerted at various particular locations on the housing component  604 . 
     The adhesive  634  and/or the housing component  604  may be flexible such that the electrodes in the first and second sets of electrodes  637  and  638  may be able to move with respect to each other independently and/or relatively independently based on where force is exerted on the housing component  604 . This may enable the processing unit  618  to more granularly determine different amounts of force exerted at different locations on the housing component  604 . 
       FIG. 7  illustrates an example implementation including a flexible housing component  704  with a strain gauge  739  disposed thereon. An exertion of force on the flexible housing component  704  may cause the flexible housing component  704  to flex, which may cause the strain gauge  739  to deflect. An electrical property of the strain gauge  739  (e.g., resistance) may change based on the deflection. As such, the processing unit  718  may accordingly receive force signals from the strain gauge  739  indicating flexing of the flexible housing component  704  via a flex circuit  740  (and/or other electrical or communication connection) and the printed circuit board  716 . The processing unit  718  may correlate the received force signals to force amounts. 
       FIG. 8  shows a flow chart illustrating an example method  800  for determining band tightness. This method  800  may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
     At  810 , a force sensor may be monitored. The force sensor may be positioned between a body of a wearable electronic device and a housing component that contacts a user&#39;s body part when the wearable electronic device is worn. 
     At  820 , one or more force signals may be received from the force sensor relating to force exerted on the housing component. The force may be the force exerted on the housing component by the user&#39;s body part and may be related to a band of the wearable electronic device causing the user&#39;s body part to exert the force based on a tightness of the band. 
     At  830 , the tightness of the band associated with the force signal from the force sensor may be determined. Higher amounts of exerted force indicated by the force signal may correlate to a tighter band. Conversely, lower amounts of exerted force indicated by the force signal may correlate to a looser band. 
     Although the example method  800  is illustrated and described as including particular operations performed in a particular order, it is understood that this is an example. In various implementations, various orders of the same, similar, and/or different operations may be performed without departing from the scope of the present disclosure. 
     For example, in various implementations, the example method  800  may include the additional operations related to band adjustment. By way of example, the example method  800  may include the additional operation of determining whether the band tightness is within a tightness range. The tightness range may be a range of force values. In some implementations of such an example, the example method  800  may include the additional operation of causing the band to be adjusted if the band tightness is not within the tightness range. In some cases, the user may be notified prior to adjustment of the band. In such cases, the user may be able to override band adjustment in response to such a notification. 
     In other implementations, the example method  800  may include the additional operation of notifying the user that the band needs adjustment if the band tightness is not within the tightness range. In such implementations, the user may be prompted to adjust the band. 
       FIG. 9  shows a flow chart illustrating an example method  900  for determining health information using a health sensor and a force sensor. This method  900  may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
     At  910 , a measurement may be received from a health sensor. For example, the health sensor may be a PPG sensor. 
     At  920 , a force signal may be received from a housing component force sensor. The housing component force sensor may be positioned between a body of a wearable electronic device and a housing component that contacts a user&#39;s body part. The force signal may indicate force exerted on the housing component by the user&#39;s body part. 
     At  930 , health information for the user may be determined based on the force signal and the measurement. For example, the force may be used to determine the tightness of a band of the wearable device, which may be used in combination with measurements of a PPG sensor to determine a blood perfusion for the user. 
     Although the example method  900  is illustrated and described as including particular operations performed in a particular order, it is understood that this is an example. In various implementations, various orders of the same, similar, and/or different operations may be performed without departing from the scope of the present disclosure. 
     For example,  930  describes the health information as being determined based on the force signal and the measurement. However, in some implementations, the health information may be determined based on the force signal or the measurement without being based on both. Further, the health information may also be based on data from one or more other sensors. 
     By way of another example, the force may be used to determine whether or not the health information is accurate. In some implementations, the health information may be accurate if the tightness of a band is within a tightness range. In such an example, the force may be used to determine the tightness of the band is within the tightness range. If the tightness of the band is not within the tightness range, the health information may be discarded as inaccurate and/or may be modified based on the force. 
       FIG. 10  shows a flow chart illustrating an example method  1000  for adjusting detected force determinations. This method  1000  may be performed by one or more of the wearable electronic devices of  FIGS. 1A-7 . 
     At  1010 , a first force signal may be received from a cover glass force sensor. The first force signal may indicate a force exerted on the cover glass (or other input device) by a user. The cover glass may be a component of a display, a touch display, and/or other assembly. 
     At  1020 , a second force signal may be received from a housing component force sensor. The housing component force sensor may be positioned between a body of a wearable electronic device and a housing component that contacts a user&#39;s body part. The housing component may be positioned on an opposite side of the wearable electronic device from the cover glass. The force signal may indicate force exerted on the housing component by the user&#39;s body part. 
     At  1030 , a force exerted on the cover glass may be determined using the first force signal. For example, a lookup table of first force signal values and force values may be consulted based on the first force signal. A force value corresponding to the value of the first force signal may be selected to determine the force exerted on the cover glass. 
     At  1040 , a force exerted on the housing component may be determined using the second force signal. For example, a lookup table of second force signal values and force values may be consulted based on the second force signal. A force value corresponding to the value of the second force signal may be selected to determine the force exerted on the housing component. 
     At  1050 , the determined force on the cover glass may be adjusted using the second force signal. For example, the second force signal may be subtracted from the determined force on the cover glass. This may allow a determined force on the cover glass to be obtained that is free of influence from forces exerted on the housing component. 
     Although the example method  1000  is illustrated and described as including particular operations performed in a particular order, it is understood that this is an example. In various implementations, various orders of the same, similar, and/or different operations may be performed without departing from the scope of the present disclosure. 
     For example,  1050  describes the determined force on the cover glass being adjusted using the second force signal. However, in various implementations, the determined force on the housing component may be adjusted using the first force signal instead of and/or in addition to adjusting the determined force on the cover glass using the second force signal. 
       FIG. 11  shows a block diagram illustrating example components that may be utilized in the wearable electronic device  100  of  FIG. 1A  and example functional relationships of those components. The wearable electronic device  100  may include one or more processing units  1151 , force sensors  1152  (such as those discussed above), storage media  1153  (such as a magnetic storage medium, an optical storage medium, a magneto-optical storage medium, a read only memory, a random access memory, an erasable programmable memory, and so on), one or more other sensors  1154  (such as one or more health sensors, accelerometers, gyroscopes, light sensors, cameras, proximity sensors, touch sensors, and so on), communication component  1155 , and/or other components. The processing unit  1151  may execute instructions stored in the storage media  1153  in order to perform various operations discussed above. 
     For example, the processing unit  1151  may receive health data from a health sensor  1154  and may store such health data in the storage media  1153 . By way of another example, the processing unit  1151  may receive force signals from the force sensor(s)  1152  and may utilize lookup tables stored in the storage media  1153  to correlate force signals to force amounts in order to determine amounts of applied forces, to compare force amounts to threshold force values, to correlate force amounts and/or threshold force values to tightnesses of a band, and so on. The processing unit  1151  may store data regarding such force signals, determined force amounts, determined tightnesses, and so on in the storage media  1153 . In examples where the processing unit  1151  determines the tightness of a band, the processing unit  1151  may compare the determined tightness of the band to tightness ranges stored in the storage media  1153  to determine whether or not the determined tightness is within such a range. 
     The wearable electronic device  100  may communicate with one or more other electronic devices, such as the electronic device  1150 , via the communication component  1155  over one or more wired and/or wireless communication connections. Similar to the wearable electronic device  100 , the electronic device  1150  may include one or more communication components  1156 , processing units  1157 , storage media  1158 , and/or other components. In various examples, the wearable electronic device  100  may transmit data and/or notifications regarding data to the electronic device  1150  via the communication components  1155  and  1156 , such as the above discussed health data, force signals, determined force amounts, determined band tightnesses, and so on. The processing unit  1157  may store such data or notifications in the storage media  1158 . 
     Alternatively and/or additionally, in some examples, the wearable electronic device  100  and the electronic device  1150  may be configured in a cooperative computing arrangement. As such, the electronic device  1150  may utilize the processing unit  1157  to process the data in one or more of the various ways the processing unit  1151  is described processing such data above. For example, the processing unit  1157  may process received health data to determine health information for a user of the wearable electronic device  100 . By way of another example, the storage media  1158  may store one or more lookup tables described above. As such, the processing unit  1157  may receive force signals and utilize the lookup tables to correlate force signals to force amounts in order to determine amounts of applied forces, to compare force amounts to threshold force values, to correlate force amounts and/or threshold force values to tightnesses of a band, and so on. The processing unit  1157  may store the results of such determinations in the storage media  1158 , transmit such results to the wearable electronic device  100 , and/or perform various other operations 
     Although the present disclosure is described as positioning force sensors between a housing component and a main body, it is understood that these are examples. In various implementations, force sensors may be positioned anywhere on a wearable electronic device that contacts a user&#39;s body part when the wearable electronic device is worn without departing from the scope of the present disclosure. For example, a force sensor may be positioned on an inner surface of a band that contacts a user&#39;s body part when the electronic device is worn. By way of another example, a force sensor may be positioned on an outer surface of the housing component that contacts a user&#39;s body part when the wearable electronic device is worn. By way of still another example, a force sensor may be positioned on a portion of the main body that contacts a user&#39;s body part when the wearable electronic device is worn. 
     Further, although the present disclosure is described in the context of a wearable electronic device  100 , it is understood that this is an example. The force sensors and/or other techniques discussed herein may be used with other devices (electronic, non-electronic, non-wearable, portable, and so on), such as the back of a smart phone, supports attached to the bottom of a laptop computer, and/or any other device without departing from the scope of the present disclosure. 
     As described above and illustrated in the accompanying figures, a wearable electronic device may include a body, a housing component (such as a plate, a curved plate, or other surface component), and a band or other attachment mechanism operable to attach the body to the body part of a user. A force sensor may be positioned between the housing component and the body such that it produces force signals based on a force exerted between the user&#39;s body part and the housing component. A processing unit may receive the force signals and process them to perform various actions. For example, the processing unit may process the force signals to determine a tightness of the band, such as for automatic band adjustment. By way of another example, the processing unit may use the force signals to determine health information for the user, such as in combination with measurements of the body part obtained via a health sensor included in the body. By way of still another example, the body may include an input mechanism (such as a touch surface including a cover glass) that interprets the force of a user&#39;s touch as input and the processing unit may use the force signals and signals from the input mechanism to adjust determinations of force applied to the housing component or input mechanism. Various uses for the force signals from the force sensor are possible and contemplated. 
     In the present disclosure, the methods disclosed may be implemented as sets of instructions or software readable by a device. Further, it is understood that the specific order or hierarchy of steps in the methods disclosed are examples of sample approaches. In other embodiments, the specific order or hierarchy of steps in the method can be rearranged while remaining within the disclosed subject matter. The accompanying method claims present elements of the various steps in a sample order, and are not necessarily meant to be limited to the specific order or hierarchy presented. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20190329
Publication Date: 20220524
Grant Date: 20220524
Priority Date: 20150928
Inventors: BUSHNELL, TYLER S.
Martisauskas, Steven J.
DE JONG, ERIK G.
BARANSKI, ANDRZEJ T.
ISIKMAN, SERHAN O.
BANASKA, STEVEN J.
WHITEHURST, TODD K.
SARTEE, MING L.
Assignee: APPLE INC
CPC Classifications: [{"code": "A61B5/4872", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/4872", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/6843", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01L1/142", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/6843", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B2562/0261", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/681", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/412", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/412", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B2562/0261", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/021", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L1/142", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/681", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/021", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L1/142", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B5/021", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/6843", "inventive": true, "first": true, "tree": "[]"}, {"code": "A61B5/681", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61B2562/0261", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/4872", "inventive": false, "first": false, "tree": "[]"}, {"code": "A61B5/412", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 58408416