Wearable skin vibration or silent gesture detector
Disclosed herein are wearable devices, their configurations, and methods of operation that use self-mixing interferometry signals of a self-mixing interferometry sensor to recognize user inputs. The user inputs may include voiced commands or silent gesture commands. The devices may be wearable on the user's head, with the self-mixing interferometry sensor configured to direct a beam of light toward a location on the user's head. Skin deformations or vibrations at the location may be caused by the user's speech or the user's silent gestures and recognized using the self-mixing interferometry signal. The self-mixing interferometry signals may be used for bioauthentication and/or audio conditioning of received sound or voice inputs to a microphone.
1. A wearable device, comprising:
a frame configured to attach the wearable device to a user;
a self-mixing interferometry sensor mounted to the frame and configured to emit a beam of light; and
a command interpreter configured to:
receive a self-mixing interferometry signal from the self-mixing interferometry sensor; and
detect skin vibration information in the self-mixing interferometry signal;
wherein:
the frame is configured to direct the beam of light toward a head of the user;
and
the command interpreter is configured to identify and authenticate a command using the skin vibration information.
2. The wearable device of claim 1 , wherein the wearable device is an earbud further comprising:
a microphone; and
an in-ear speaker; and wherein:
the self-mixing interferometry sensor directs the beam of light toward a location in an ear of the user; and
the command interpreter identifies a voiced command of the user using the skin vibration information.
3. The wearable device of claim 1 , wherein:
the wearable device is an eyeglasses set;
the self-mixing interferometry sensor is mounted to an arm of the eyeglasses set and directs the beam of light toward a location proximate to a temporal bone of the user; and
the command interpreter identifies a voiced command of the user based on the skin vibration information.
4. The wearable device of claim 1 , wherein the skin vibration information includes temporomandibular joint movement information.
5. The wearable device of claim 4 , wherein:
the wearable device is a headphone;
the self-mixing interferometry sensor directs the beam of light toward a location on the user's head proximate to a temporomandibular joint of the user; and
the command interpreter identifies the temporomandibular joint movement information as a silent gesture command of the user.
6. The wearable device of claim 4 , wherein:
the wearable device is a visual display headset;
the self-mixing interferometry sensor is a first self-mixing interferometry sensor;
the beam of light is a first beam of light;
the self-mixing interferometry signal is a first self-mixing interferometry signal;
the first self-mixing interferometry sensor directs the beam of light toward a first location on the user's head proximate to a temporomandibular joint of the user;
the command interpreter identifies the temporomandibular joint movement information as a silent gesture command of the user;
the wearable device comprises a second self-mixing interferometry sensor that directs a second beam of light toward a second location on the user's head proximate to a parietal bone; and
the command interpreter is configured to receive a second self-mixing interferometry signal from the second self-mixing interferometry sensor; wherein:
the second self-mixing interferometry signal includes skin vibration information; and
the command interpreter is configured to identify a voiced command encoded in the skin vibration information of the second self-mixing interferometry signal.
7. The wearable device of claim 1 , wherein:
the beam of light is a laser light beam emitted by a laser diode;
a bias current of the laser diode is modulated with a sine wave; and
the command interpreter is configured to use a time domain I/Q analysis to identify the command encoded in the skin vibration information.
8. The wearable device of claim 1 , wherein:
the beam of light is a laser light emitted by a laser diode;
a bias current of the laser diode is modulated with a triangle wave; and
the command interpreter is configured to use a spectrum analysis to identify the command encoded in the skin vibration information.
9. A device, comprising:
a head-mountable frame configured to be worn by a user;
a self-mixing interferometry sensor mounted to the head-mountable frame and configured to emit a beam of light toward a location on the user's head;
a microphone;
a command interpreter configured to receive an output of the microphone and recognize a voiced command of the user; and
a bioauthentication circuit configured to:
determine skin vibration information from the received light of the emitted beam of light; and
authenticate the voiced command using the skin vibration information of the self-mixing interferometry sensor.
10. The device of claim 9 , wherein:
the received light includes skin deformation information;
the bioauthentication circuit is operable to:
detect, using at least the skin deformation information, that the user was speaking during a time interval of the received output of the microphone; and
authenticate the voiced command using the detection.
11. The device of claim 10 , wherein authentication of the voiced command further includes detecting a correlation of the voiced command of the user with a voice pattern detected in the skin vibration information.
12. The device of claim 9 , wherein the device is an earbud further comprising:
an in-ear speaker; and
a radio transmitter; wherein:
the device transmits the voiced command using the radio transmitter upon authentication.
13. The device of claim 9 , wherein:
the device is a headphone;
the location on the user's head is proximate to at least one of a temporal bone and a parietal bone; and
the device implements the voiced command upon authentication.
14. The device of claim 9 , wherein:
the beam of light is a laser light beam emitted by a laser diode;
the bioauthentication circuit is configured to authenticate the voiced command using at least one of:
a time domain I/Q analysis of the received light when a sine wave modulation is applied to a bias current of the laser diode, and
a spectrum analysis of the received light when a triangle wave modulation is applied to the bias current of the laser diode.
15. A device, comprising:
a head-mountable frame configured to be worn by a user;
a self-mixing interferometry sensor mounted to the head-mountable frame and configured to emit a beam of light toward skin of the user and determine skin vibration information from a detected portion of the beam of light;
a microphone configured to produce an audio signal; and
an audio conditioning circuit configured to modify the audio signal using a self-mixing interferometry signal of the self-mixing interferometry sensor to detect intervals of speech using the skin vibration information and suppress background noise in the audio signal.
16. The device of claim 15 , wherein the device is an earbud further comprising:
an in-ear speaker; and
a radio transmitter; wherein:
the device transmits the audio signal only during the detected time intervals of speech of the user.
17. The device of claim 15 , wherein:
the device is a headphone further comprising a radio transmitter;
the self-mixing interferometry sensor directs the beam of light toward a location on the user's head proximate to at least one of the a temporal bone and the a parietal bone; and
the device transmits the audio signal only during the detected time intervals of speech of the user.
18. The device of claim 15 , wherein:
the beam of light is a laser light beam emitted by a laser diode;
the audio conditioning circuit is configured to modify the audio signal using at least one of:
a time domain I/Q analysis of the self-mixing interferometry signal when a sine wave modulation is applied to a bias current of the laser diode, and
a spectrum analysis of the self-mixing interferometry signal when a triangle wave modulation is applied to the bias current of the laser diode.