Physiological data collection

• US 9,662,053 B2
• Filed: 06/28/2016
• Issued: 05/30/2017
• Est. Priority Date: 06/22/2012
• Status: Active Grant

• Current Assignee: Fitbit, Inc. (Alphabet Inc.)
• Original Assignee: Fitbit, Inc. (Alphabet Inc.)
• Inventors: Elliot, Thomas Samuel, Richards, Peter W., Yuen, Shelten Gee Jao
• Primary Examiner(s): Lamprecht, Joel
• Application Number:
  US15/195,911
• Publication Number:
  US 20160302706A1
• Time in Patent Office: 336 Days
• CPC Class Codes: A61B 2562/185 Optical shielding, e.g. baffles
• 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 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• 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 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• 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 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 : Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• 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: 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

In some implementations, a device includes light emitter(s) to emit first light having a first wavelength and second light having a second wavelength. The device also includes light detector(s) to generate a first electrical signal while the light emitter emits the first light, a second electrical signal while the light emitter emits the second light, and a third electrical signal while the light emitter is not emitting light. The device also includes ambient light cancellation circuit(s) to generate a countering signal to counter a portion of one or both of the first and second electrical signals based on the third electrical signal. The device also includes analog to digital converter(s) to generate first and second digital signals based on values of the first and second electrical signals, respectively. The device further includes a controller to determine a saturation of peripheral oxygen metric based on the first and second digital signals.

Claims

1. A portable monitoring device comprising:

at least one light emitter to emit first light having a first wavelength in a first range of wavelengths and second light having a second wavelength in a second range of wavelengths;

at least one light detector to generate a first electrical signal based on light detected by the light detector while the light emitter emits the first light, a second electrical signal based on light detected by the light detector while the light emitter emits the second light, and a third electrical signal based on ambient light detected while the light emitter is not emitting light;

at least one ambient light cancellation circuit to generate a countering signal to counter a portion of one or both of the first and the second electrical signals associated with an ambient light component, the ambient light cancellation circuit generating the countering signal based on a value of the third electrical signal;

at least one analog to digital converter (ADC) to generate a first digital signal based on values of the first electrical signal and to generate a second digital signal based on values of the second electrical signal; and

a controller to control operation of the at least one light emitter, the at least one light detector and the ambient light cancellation circuit, the controller being further configured to determine or update a saturation of peripheral oxygen (SpO₂) metric based on the first digital signal and the second digital signal.

2. The portable monitoring device of claim 1, wherein:

the at least one light emitter is further configured to emit third light having a third wavelength in a third range of wavelengths;

the at least one light detector is further configured to generate a fourth electrical signal based on light detected by the light detector while the light emitter emits the third light;

the ADC is further configured to generate a third digital signal based on values of the fourth electrical signal; and

the controller is further configured to determine or update a second physiological metric based on the third digital signal.

3. The portable monitoring device of claim 2, wherein the second physiological metric is one of a heart rate, a heart rate variability, a blood pressure, a blood volume, a blood glucose level, a respiration rate, or a skin pigmentation level.

4. The portable monitoring device of claim 2, wherein the third range of wavelengths is associated with the green spectrum.

5. The portable monitoring device of claim 2, wherein the controller is further configured to determine or update a third physiological metric based on the first physiological metric and the second physiological metric.

6. The portable monitoring device of claim 1, wherein the first range of wavelengths is associated with the red spectrum and the second range of wavelengths is associated with the infrared spectrum.

7. The portable monitoring device of claim 1, further including a gain circuit to provide a gain adjustment signal to set a gain of one or more of the first, the second or the third electrical signals.

8. The portable monitoring device of claim 1, further including:

a sampling circuit to capture samples of the first, the second and the third electrical signals; and

a switching circuit capable of transitioning among at least a first configuration and a second configuration, the controller being further configured to;

cause the switching circuit to transition to the first configuration to enable the capturing of a sample of the first or the second electrical signal; and

cause the switching circuit to transition to the second configuration to enable the capturing of the sample of the third electrical signal.

9. The portable monitoring device of claim 8, wherein the countering signal is generated based on an electrical charge proportional to a voltage value of the captured sample of the third electrical signal.

10. A method comprising:

emitting, by at least one light emitter, first light having a first wavelength in a first range of wavelengths;

generating, by at least one light detector, a first electrical signal based on light detected by the light detector while the light emitter emits the first light;

generating, by at least one ambient light cancellation circuit, a first countering signal based on a value of an electrical signal generated by the light detector while the light emitter is not emitting light;

countering, using the first countering signal, a portion of the first electrical signal associated with an ambient light component;

generating, by at least one analog to digital converter (ADC), a first digital signal based on values of the first electrical signal;

emitting, by the at least one light emitter, second light having a second wavelength in a second range of wavelengths;

generating, by the at least one light detector, a second electrical signal based on light detected by the light detector while the light emitter emits the second light;

generating, by the at least one ambient light cancellation circuit, a second countering signal based on a value of an electrical signal generated by the light detector while the light emitter is not emitting light;

countering, using the second countering signal, a portion of the second electrical signal associated with an ambient light component;

generating, by the at least one ADC, a second digital signal based on values of the second electrical signal; and

determining or updating, by a controller, a saturation of peripheral oxygen (SpO₂) metric based on the first digital signal and the second digital signal.

11. The method of claim 10, further including:

emitting, by the at least one light emitter, third light having a third wavelength in a third range of wavelengths;

generating, by the at least one light detector, a fourth electrical signal based on light detected by the light detector while the light emitter emits the third light;

generating, by the at least one ADC, a third digital signal based on values of the fourth electrical signal; and

determining or updating, by the controller, a second physiological metric based on the third digital signal.

12. The method of claim 11, wherein the second physiological metric is one of a heart rate, a heart rate variability, a blood pressure, a blood volume, a blood glucose level, a respiration rate, or a skin pigmentation level.

13. The method of claim 11, wherein the third range of wavelengths is associated with the green spectrum.

14. The method of claim 11, further including determining or updating, by the controller, a third physiological metric based on the first physiological metric and the second physiological metric.

15. The method of claim 10, wherein the first range of wavelengths is associated with the red spectrum and the second range of wavelengths is associated with the infrared spectrum.

16. The method of claim 10, further including adjusting, by at least one gain circuit, a gain associated with one or more of the first, the second or the third electrical signals.

17. The method of claim 10, further including:

causing, by the controller, a switching circuit to transition to a first configuration to enable the capturing of a sample of the first or the second electrical signal;

capturing, by a sampling circuit, a sample of the first or the second electrical signal;

causing, by the controller, the switching circuit to transition to a second configuration to enable the capturing of a sample of the third electrical signal; and

capturing, by the sampling circuit, a sample of the third electrical signal.

18. The method of claim 17, wherein one or both of the first and the second countering signals is generated based on an electrical charge proportional to a voltage value of the captured sample of the third electrical signal.

19. Non-transitory storage media including processor-executable code that, when executed, is configured to:

cause at least one light emitter to emit first light having a first wavelength in a first range of wavelengths;

cause at least one light detector to generate a first electrical signal based on light detected by the light detector while the light emitter emits the first light;

cause at least one ambient light cancellation circuit to generate a first countering signal based on a value of an electrical signal generated by the light detector while the light emitter is not emitting light;

cause the at least one ambient light cancellation circuit to counter, using the first countering signal, a portion of the first electrical signal associated with an ambient light component;

cause at least one an analog to digital converter (ADC) to generate a first digital signal based on values of the first electrical signal;

cause the at least one light emitter to emit second light having a second wavelength in a second range of wavelengths;

cause the at least one light detector to generate a second electrical signal based on light detected by the light detector while the light emitter emits the second light;

cause the at least one ambient light cancellation circuit to generate a second countering signal based on a value of an electrical signal generated by the light detector while the light emitter is not emitting light;

cause the at least one ambient light cancellation circuit to counter, using the second countering signal, a portion of the second electrical signal associated with an ambient light component;

cause the at least one ADC to generate a second digital signal based on values of the second electrical signal; and

determine or update a saturation of peripheral oxygen (SpO₂) metric based on the first digital signal and the second digital signal.

20. The media of claim 19, further including processor-executable code configured to:

cause the at least one light emitter to emit third light having a third wavelength in a third range of wavelengths;

cause the at least one light detector to generate a fourth electrical signal based on light detected by the light detector while the light emitter emits the third light;

cause the at least one ADC to generate a third digital signal based on values of the fourth electrical signal; and

determine or update a second physiological metric based on the third digital signal.

21. The media of claim 20, wherein the second physiological metric is one of a heart rate, a heart rate variability, a blood pressure, a blood volume, a blood glucose level, a respiration rate, or a skin pigmentation level.

22. The media of claim 20, wherein the third range of wavelengths is associated with the green spectrum.

23. The media of claim 20, further including processor-executable code configured to determine or update a third physiological metric based on the first physiological metric and the second physiological metric.

24. The media of claim 19, wherein the first range of wavelengths is associated with the red spectrum and the second range of wavelengths is associated with the infrared spectrum.

25. The media of claim 19, further including processor-executable code configured to cause a gain adjustment circuit to adjust a gain associated with one or more of the first, the second or the third electrical signals.

26. The media of claim 19, further including processor-executable code configured to:

cause a switching circuit to transition to a first configuration to enable the capturing of a sample of the first or the second electrical signal;

cause at least one sampling circuit to capture a sample of the first or the second electrical signal;

cause the switching circuit to transition to a second configuration to enable the capturing of a sample of the third electrical signal; and

cause the at least one sampling circuit to capture a sample of the third electrical signal.

27. The media of claim 26, wherein one or both of the first and the second countering signals is generated based on an electrical charge proportional to a voltage value of the captured sample of the third electrical signal.