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 and to direct a beam of light toward a skin portion of the user;
a self-mixing interferometry sensor mounted to the frame and configured to emit the beam of light; and
an interpreter configured to:
receive a self-mixing interferometry signal from the self-mixing interferometry sensor;
detect skin vibration information in the self-mixing interferometry signal; and
transmit one or more signals responsive to a detection of the skin vibration information in the self-mixing interferometry signal.
2. The wearable device of claim 1 , wherein:
the frame defines an earbud;
the wearable device further comprises:
a microphone; and
an in-ear speaker;
the frame directs the beam of light toward a location in an ear of the user; and
the interpreter identifies a voiced command of the user using the skin vibration information.
3. The wearable device of claim 1 , wherein:
the frame defines an eyeglass set including an arm;
the self-mixing interferometry sensor is mounted to the arm;
the arm directs the beam of light toward a location proximate to a temporal bone of the user; and
the interpreter identifies a voiced command of the user based on the skin vibration information.
4. The wearable device of claim 1 , wherein interpreter is further configured to:
detect temporomandibular joint movement information corresponding to the skin vibration information in the self-mixing interferometry signal.
5. The wearable device of claim 4 , wherein interpreter is further configured to:
identify the temporomandibular joint movement information as a silent gesture command of the user.
6. The wearable device of claim 1 , wherein:
the beam of light is a first beam of light;
the wearable device directs a second beam of light toward the skin portion of the user; and
the interpreter is configured to receive a second self-mixing interferometry signal based at least in part on the second beam of light.
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 interpreter is configured to use a time domain I/O analysis to detect the skin vibration information in the self-mixing interferometry signal.
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 interpreter is configured to use a spectrum analysis to detect the skin vibration information in the self-mixing interferometry signal.
9. The wearable device of claim 1 , wherein the interpreter is a command interpreter configured to identify a voiced command encoded in the skin vibration information.
10. A device, comprising:
a frame configured to be worn by a user;
a self-mixing interferometry sensor mounted to the frame and configured to emit a beam of light toward a location on a skin portion of the user; and
an interpreter configured to:
receive a self-mixing interferometry signal from the self-mixing interferometry sensor;
detect a first skin vibration information in the self-mixing interferometry signal;
detect a second skin vibration information in the self-mixing interferometry signal, wherein the second skin vibration information includes vibration information different from the first skin vibration information; and
transmit one or more signals responsive to a detection of the second skin vibration information in the self-mixing interferometry signal, the one or more signals indicating a movement unrelated to a voiced command.
11. The device of claim 10 , further comprising:
a microphone; wherein:
the interpreter is configured to:
receive an output of the microphone;
determine the first skin vibration information in the self-mixing interferometry signal based at least in part on a voiced command from the output of the microphone; and
send one more second signals indicating a movement related to the voiced command.
12. The device of claim 11 , the interpreter is configured to:
detect a correlation of the voiced command of the user with a voice pattern detected in the first skin vibration information.
13. The device of claim 11 , further comprising:
a bioauthentication circuit configured to:
authenticate the voiced command using a self-mixing interferometry signal of the self-mixing interferometry sensor; wherein:
the self-mixing interferometry signal includes the first skin vibration information.
14. The device of claim 13 , the bioauthentication circuit is configured to:
determine that the user was speaking during a time interval of the received output of the microphone based at least in part on the first skin vibration information; and
authenticate the voiced command using a detection that the user was speaking during the time interval.
15. The device of claim 10 , wherein:
the frame is a head-mountable frame; and
the location on the skin portion of the user is proximate to at least one of a temporal bone and a parietal bone.
16. A device, comprising:
a frame configured to be worn by a user;
a self-mixing interferometry sensor mounted to the frame and configured to emit a beam of light toward skin of the user; and
an audio conditioning circuit configured to:
receive a self-mixing interferometry signal from the self-mixing interferometry sensor;
detect skin vibration information in the self-mixing interferometry signal; and
determine time intervals of non-speech of the user based at least in part on a detection of the skin vibration information.
17. The device of claim 16 , further comprising:
a microphone configured to produce an audio signal; wherein the audio conditioning circuit is configured to:
modify the audio signal using the self-mixing interferometry signal of the self-mixing interferometry sensor based at least in part on a determination of the time intervals of non-speech of the user.
18. The device of claim 17 , wherein the audio conditioning circuit is configured to modify the audio signal is further configure to:
suppress background noise during a time segment in the determined time intervals of non-speech of the user modify the audio signal.
19. The device of claim 16 , further comprising:
a microphone configured to produce an audio signal; wherein the audio conditioning circuit is configured to:
determine time intervals of speech of the user based at least in part on the detection of the skin vibration information; and
refrain from modifying the audio signal based at least in part on a determination of the time intervals of speech of the user.
20. The device of claim 16 , wherein:
the beam of light is a laser light beam emitted by a laser diode; and
the audio conditioning circuit is configured to modify an audio signal using at least one of:
a time domain I/O 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.