Motion gesture input detected using optical sensors

Abstract

A wearable device with an optical sensor is disclosed that can be used to recognize gestures of a user wearing the device. Light sources can be positioned on the back or skin-facing side of a wearable device, and an optical sensor can be positioned near the light sources. During operation, light can be emitted from the light sources and sensed using the optical sensor. Changes in the sensed light can be used to recognize user gestures. For example, light emitted from a light source can reflect off a wearer's skin, and the reflected light can be sensed using the optical sensor. When the wearer gestures in a particular way, the reflected light can change perceptibly due to muscle contraction, device shifting, skin stretching, or the distance changing between the optical sensor and the wearer's skin. Recognized gestures can be interpreted as commands for interacting with the wearable device.

1 . A computer-implemented method for determining gestures, the method comprising:
 causing light to be emitted from a wearable user device;   sensing a portion of the light that is reflected by a wearer's skin; and   determining a gesture made by the wearer based on changes in the sensed portion of the light.   
     
     
         2 . The method of  claim 1 , wherein the changes in the sensed portion of the light correspond to a change in a distance between an optical sensor of the wearable user device and the wearer's skin; and
 wherein sensing the portion of the light that is reflected by the wearer's skin comprises sensing the portion of the light using the optical sensor.   
     
     
         3 . The method of  claim 1 , wherein the changes in the sensed portion of the light correspond to a change in an intensity of the sensed portion of the light reflected by the wearer's skin. 
     
     
         4 . The method of  claim 1 , wherein causing the light to be emitted from the wearable user device comprises:
 causing the light to be emitted from a first LED at a first wavelength and a second LED at a second wavelength that is different from the first wavelength.   
     
     
         5 . The method of  claim 1 , wherein causing the light to be emitted from the wearable user device comprises:
 causing the light to be emitted at an angle relative to the wearable device, wherein the emitted light is incident on the wearer's skin at a non-perpendicular angle.   
     
     
         6 . The method of  claim 1 , wherein sensing the portion of the light that is reflected by the wearer's skin comprises:
 generating a signal based on the sensed portion of the light using an optical sensor positioned between a first LED and a second LED; and   wherein causing the light to be emitted from the wearable user device comprises causing the light to be emitted from the first LED and the second LED.   
     
     
         7 . The method of  claim 1 , wherein determining the gesture based on changes in the sensed portion of the light comprises:
 identifying a positive peak, a negative peak, and a zero crossing in a derivative of a signal generated by an optical sensor used for sensing the portion of the light that is reflected by the wearer's skin.   
     
     
         8 . The method of  claim 1 , wherein the gesture comprises a first clench. 
     
     
         9 - 10 . (canceled) 
     
     
         11 . A wearable device for determining gestures, the device comprising:
 a light source configured to emit light from the device toward a wearer's skin when the wearable device is worn;   an optical sensor configured to generate a signal based on sensing a portion of the light reflected by the wearer's skin;   a non-transitory computer-readable storage medium comprising computer-executable instructions for determining a gesture made by the wearer based on changes in the signal; and   a processor coupled to receive the signal, wherein the processor is capable of executing the computer-executable instructions.   
     
     
         12 . The wearable device of  claim 11 , wherein the changes in the signal correspond to a change in a distance between the optical sensor and the wearer's skin. 
     
     
         13 . The wearable device of  claim 11 , wherein the signal generated by the optical sensor changes based on an intensity of the sensed portion of the light reflected by the wearer's skin. 
     
     
         14 . The wearable device of  claim 11 , wherein the light source comprises a first LED configured to emit light at a first wavelength and a second LED configured to emit light at a second wavelength that is different from the first wavelength. 
     
     
         15 . The wearable device of  claim 11 , wherein the light source comprises a first LED and a second LED; and
 wherein the optical sensor is positioned between the first LED and the second LED.   
     
     
         16 . The wearable device of  claim 11 , wherein the light source is angled relative to the wearable device to direct light to be incident on the wearer's skin at a non-perpendicular angle. 
     
     
         17 . The wearable device of  claim 11 , wherein the computer-executable instructions for determining the gesture comprise computer-executable instructions for determining the gesture by identifying a positive peak, a negative peak, and a zero crossing in a derivative of the signal. 
     
     
         18 . The wearable device of  claim 11 , wherein the gesture comprises a first clench. 
     
     
         19 . The wearable device of  claim 11 , wherein the optical sensor is configured to sense a wavelength of light that corresponds to a wavelength of light emitted by the light source. 
     
     
         20 . A system for determining gestures, the system comprising:
 a light source configured to emit light from a wearable user device toward a wearer's skin when the wearable user device is worn;   an optical sensor configured to generate a signal based on sensing a portion of the light reflected by the wearer's skin;   a non-transitory computer-readable storage medium comprising computer-executable instructions for determining a gesture made by the wearer based on changes in the signal;   a processor coupled to receive the signal, wherein the processor is capable of executing the computer-executable instructions; and   a communication module coupled to the processor, wherein the communication module is configured to communicate with a mobile device.   
     
     
         21 . The system of  claim 20 , wherein the non-transitory computer-readable storage medium further comprises instructions for communicating a command to the mobile device via the communication module in response to determining the gesture. 
     
     
         22 . A computer-implemented method for indirectly determining a hand gesture using a wearable device worn on a wearer's wrist, the method comprising:
 causing light to be emitted toward the wearer's wrist from a light source of the wearable device, wherein the light source is positioned proximate to skin at the wearer's wrist;   sensing a portion of the light that is reflected by the skin at the wearer's wrist using an optical sensor of the wearable device, wherein the optical sensor is positioned proximate to the skin at the wearer's wrist;   indirectly determining a hand gesture made by the wearer based on a change in the sensed portion of the light that is reflected by the skin at the wearer's wrist, wherein the change results from a distance between the optical sensor and the skin at the wearer's wrist increasing or decreasing due to the hand gesture.   
     
     
         23 - 25 . (canceled)