HEART RATE DATA COLLECTION

• US 20140358012A1
• Filed: 05/31/2014
• Published: 12/04/2014
• Est. Priority Date: 06/03/2013
• Status: Active Grant

• Current Assignee: Fitbit, Inc. (Alphabet Inc.)
• Original Assignee: Fitbit, Inc. (Alphabet Inc.)
• Inventors: Richards, Peter W., Elliot, Thomas Samuel, Yuen, Shelten Gee Jao
• Granted Patent: US 9,014,790 B2
• Time in Patent Office: Days
• US Class Current: 600/479
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02433 for infrared radiation
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/6802 Sensor mounted on worn items
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04N 21/42201 biosensors, e.g. heat sensor for presence detection, EEG sensors or any limb activity sensors worn by the user input arrangements for interaction with the human body based on nervous system activity detection G06F3/015
• CPC Class Codes: H04N 21/44218 Detecting physical presence or behaviour of the user, e.g. using sensors to detect if the user is leaving the room or changes his face expression during a TV program methods or arrangements for recognising human body or animal bodies or body parts G06V40/10; methods or arrangements for acquiring or recognising human faces, facial parts, facial sketches, facial expressions G06V40/16; methods or arrangements for recognising movements or behaviour G06V40/20; arrangements for identifying users in broadcast systems H04H60/45
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

One innovative aspect is directed to heart rate data collection. In some implementations, a circuit includes a light detector for generating a first electrical signal based on received light. The circuit includes a switching circuit, having a first and a second configuration, configured to receive a first voltage signal based on the first electrical signal and to switch among the first and the second configurations. The circuit includes first and second sampling circuits for sampling a value of the first voltage signal when the switching circuit is in the first configuration and second configurations, respectively. The circuit includes an ambient light cancellation circuit for generating a current signal to counter a first component of the first electrical signal when the first switching circuit is in the first configuration.

Claims

1. A method performed in response to a request to perform a sampling process, the method comprising:

setting, by a controller, a gain of at least a first amplifier in at least a first sampling circuit;

causing a light emitter to emit a light signal;

operating said at least first sampling circuit to sample a detected incident light signal to produce an analog representation of said detected incident light signal;

operating an analog to digital converter to convert said analog representation of said detected incident light signal into a digital representation for further processing by said controller; and

substantially simultaneously with said operating said analog to digital converter, disabling said light emitter and said at least first sampling circuit.

2. The method of claim 1, wherein said detected incident light signal is a light signal obtained from a target.

3. The method of claim 1, further comprising:

setting, by said controller, a gain of an ambient light detection process;

causing a light detector to detect an ambient light signal; and

sampling said ambient light signal at least partially based on said gain of said ambient light detection process to produce an analog representation of said ambient light signal.

4. The method of claim 2, wherein said analog representation of said detected incident light signal is countered by said analog representation of said ambient light signal.

5. The method of claim 4, wherein said operating of said analog to digital converter is performed after a first delay period, said first delay period selected to allow said detected incident light signal to be countered by said analog representation of said ambient light signal.

6. The method of claim 4, wherein said operating of said analog to digital converter is performed after a first delay period, said first delay period selected to allow said analog to digital to settle to a known state.

7. The method of claim 1, further comprising:

prior to causing said light emitter to emit said light signal, disabling a zeroing of a light detector.

8. The method of claim 7, further comprising:

after said disabling of said light emitter, enabling a zeroing of said light detector.

9. The method of claim 1, further comprising:

resetting said light emitter, said at least first sampling circuit, and said at least first amplifier in preparation for a further request to perform a sampling process.

10. The method of claim 3, wherein said sampling said ambient light signal is performed using a second sampling circuit, wherein said gain of said ambient light detection process is provided to said second sampling circuit to:

adjust or select an impedance; and

generate a gain adjustment signal to adjust a gain of said analog representation of said ambient light signal.

11. The method of claim 1, wherein said gain of at least said first amplifier is set based at least in part on historical data received by said controller.

12. The method of claim 3, wherein said gain of said ambient light detection process is set based at least in part on historical ambient light data received by said controller.

13. The method of claim 1, wherein said digital representation is representative of a detected heartbeat of a user.

14. A non-transitory computer-readable medium storing program code, the program code executable by a processor of a computing system to cause the computing system to:

receive a request to perform a sampling process;

set a gain of at least a first amplifier in at least a first sampling circuit;

cause a light emitter to emit a light signal;

operate said at least first sampling circuit to sample a detected incident light signal to produce an analog representation of said detected incident light signal;

operate an analog to digital converter to convert said analog representation of said detected incident light signal into a digital representation for further processing by said controller; and

substantially simultaneously with said operating said analog to digital converter, disable said light emitter and said at least first sampling circuit.

15. The non-transitory computer-readable medium storing program code of claim 14 further comprising program code executable by a processor of a computing system to cause the computing system to:

set a gain of an ambient light detection process;

cause a light detector to detect an ambient light signal; and

sample said ambient light signal at least partially based on said gain of said ambient light detection process to produce an analog representation of said ambient light signal.

16. The non-transitory computer-readable medium storing program code of claim 15 wherein said detected incident light signal is a light signal obtained from a target.

17. The non-transitory computer-readable medium storing program code of claim 15 wherein said analog representation of said detected incident light signal is countered by said analog representation of said ambient light signal.

18. The non-transitory computer-readable medium storing program code of claim 17, wherein said program code executable by a processor of a computing system to cause the computing system to operate said analog to digital converter further includes program code to insert a first delay period selected to allow said detected incident light signal to be countered by said analog representation of said ambient light signal.

19. The non-transitory computer-readable medium storing program code of claim 17, wherein said program code executable by a processor of a computing system to cause the computing system to operate said analog to digital converter further includes program code to insert a first delay period selected to allow said analog to digital to settle to a known state.

20. A method for operating a biometric monitoring device, comprising:

receiving, by a controller, a request to initiate a biometric capture process;

setting, in response to said request, a gain of at least a first amplifier in at least a first sampling circuit;

causing a light emitter to emit a light signal toward a target surface;

operating said at least first sampling circuit to sample a detected incident light signal to produce an analog representation of said detected incident light signal;

operating an analog to digital converter to convert said analog representation of said detected incident light signal into a digital representation for further processing by said controller to complete said biometric capture process; and

substantially simultaneously with said operating said analog to digital converter, disabling said light emitter and said at least first sampling circuit.

21. The method of claim 20, wherein said digital representation is representative of a heartbeat of a user of said biometric monitoring device.

23. The method of claim 20, further comprising:

prior to causing said light emitter to emit said light signal, disabling a zeroing of a light detector.

24. The method of claim 23, further comprising:

after said disabling of said light emitter, enabling a zeroing of said light detector.

25. The method of claim 20, further comprising:

resetting said light emitter, said at least first sampling circuit, and said at least first amplifier in preparation for a further request to perform a sampling process.

27. The method of claim 20, wherein said gain of at least said first amplifier is set based at least in part on historical data received by said controller.

22. The method of claim 22, further comprising:

setting, by said controller, a gain of an ambient light detection process;

causing a light detector to detect an ambient light signal; and

sampling said ambient light signal at least partially based on said gain of said ambient light detection process to produce an analog representation of said ambient light signal for use in canceling an ambient component of said analog representation of said detected light signal.

26. The method of claim 22, wherein said sampling said ambient light signal is performed using a second sampling circuit, wherein said gain of said ambient light detection process is provided to said second sampling circuit to:

adjust or select an impedance; and

generate a gain adjustment signal to adjust a gain of said analog representation of said ambient light signal.

28. The method of claim 22, wherein said gain of said ambient light detection process is set based at least in part on historical ambient light data received by said controller.