Wearable device for sensing physiological information

• US 10,085,691 B2
• Filed: 08/06/2015
• Issued: 10/02/2018
• Est. Priority Date: 08/06/2015
• Status: Active Grant

• Current Assignee: ASUSTek Computer, Inc.
• Original Assignee: ASUSTek Computer, Inc.
• Inventors: Wu, Tung-Ke
• Primary Examiner(s): Stock, Jr., Gordon J
• Application Number:
  US14/819,447
• Publication Number:
  US 20170035353A1
• Time in Patent Office: 1,153 Days
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6802 Sensor mounted on worn items
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• 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: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt

Abstract

A wearable device is provided. The wearable device includes an optical sensor and a controller. The optical sensor is adapted to emit at least one optical signal, and receive at least one reflective signal corresponding to the at least one optical signal. The at least one reflective signal includes a physiological information. The controller is coupled to the optical sensor, and includes a signal filter. The signal filter is adapted to perform a signal processing operation to the at least one reflective signal according to at least one signal processing parameter. The controller adjusts the at least one signal processing parameter of the signal filter according to the physiological information. A method of operating the wearable device is also provided.

Claims

1. A wearable device, comprising:

an optical sensor, adapted to emit at least one optical signal, and receive at least one reflective signal corresponding to the at least one optical signal; and

a controller, coupled to the optical sensor, and adapted to perform a signal processing operation to the at least one reflective signal according to at least one signal processing parameter, wherein the controller adjusts the at least one signal processing parameter of a signal filter according to physiological information,

wherein the signal processing operation comprises calculating a raw data of the at least one reflective signal to obtain a moving average, subtracting the moving average from the raw data to obtain a difference, and determining if the difference is greater than a predetermined threshold value,

wherein when the difference is greater than the predetermined threshold value, the wearable device is in a first usage status, and when the difference is less than the predetermined threshold value, the wearable device is in a second usage status.

2. The wearable device as claimed in claim 1, further comprising:

an accelerometer, coupled to the controller, and adapted to detect an acceleration of the wearable device,

wherein the controller determines if the wearable device is in a static state according to a sensing result of the accelerometer, and when the wearable device is in the static state, the controller controls the optical sensor to emit the at least one optical signal, and receive the at least one reflective signal.

3. The wearable device as claimed in claim 1, wherein the signal processing operation comprises performing a Fast Fourier Transformation (FFT) operation towards the at least one reflective signal to identify a peak frequency within a frequency range, wherein when the at least one reflective signal has the peak frequency within the frequency processing range, the wearable device is in a first usage status, and

when the at least one reflective signal does not have the peak frequency within the frequency processing range, the wearable device is in a second usage status.

4. The wearable device as claimed in claim 1, wherein the controller further comprises the signal filter, wherein the signal filter is adapted to perform the signal processing operation to the at least one reflective signal according to the at least one signal processing parameter, the at least one reflective signal comprises the physiological information,

wherein the controller sets a frequency processing range of the signal filter according to the physiological information, and the signal filter performs the signal processing operation to the at least one reflective signal within the frequency processing range.

5. The wearable device as claimed in claim 4, wherein when the at least one reflective signal has a peak frequency within the frequency processing range, the wearable device is in a first usage status, and

when the at least one reflective signal does not have the peak frequency within the frequency processing range, the wearable device is in a second usage status.

6. The wearable device as claimed in claim 4, wherein the controller sets a signal gain of the signal filter according to the physiological information, and the signal filter performs the signal processing operation to the at least one reflective signal according to the signal gain.

7. The wearable device as claimed in claim 6, wherein the optical sensor receives the at least one reflective signal with different intensities when corresponding to a plurality of different test objects, and the controller determines the physiological information of the test objects according to the different intensities of the at least one reflective signal.

8. The wearable device as claimed in claim 7, wherein the at least one optical signal comprises a first optical signal and a second optical signal, respectively becoming a first reflective signal and a second reflective signal when reflecting off the different test objects, wherein an intensity variation of the first reflective signal is greater than an intensity variation of the second reflective signal, and the controller determines the physiological information of the test objects according to the different intensities of the first reflective signal.

9. The wearable device as claimed in claim 8, wherein the controller determines a usage status of the wearable device according to the different intensities of the second reflective signal.

10. A method of operating a wearable device, comprising:

emitting at least one optical signal, and receiving at least one reflective signal corresponding to the at least one optical signal through an optical sensor;

adjusting at least one signal processing parameter of a signal filter according to physiological information of the at least one reflective signal through a controller; and

performing a signal processing operation to the at least one reflective signal according to the at least one signal processing parameter through the controller, wherein performing a signal processing operation to the at least one reflective signal according to at least one signal processing parameter comprises;

calculating a raw data of the at least one reflective signal to obtain a moving average;

subtracting the moving average from the raw data to obtain a difference; and

determining if the difference is greater than a predetermined threshold value,

wherein when the difference is greater than the predetermined threshold value, the wearable device is in a first usage status, and when the difference is less than the predetermined threshold value, the wearable device is in a second usage status.

11. The method as claimed in claim 10, further comprising:

determining if the wearable device is in a static state according to a sensing result of an accelerometer; and

when the wearable device is in the static state, emitting the at least one optical signal, and receiving the at least one reflective signal.

12. The wearable device as claimed in claim 10, performing a signal processing operation to the at least one reflective signal according to at least one signal processing parameter comprises:

performing a Fast Fourier Transformation (FFT) operation towards the at least one reflective signal to identify a peak frequency within a frequency range, wherein when the at least one reflective signal has the peak frequency within the frequency processing range, the wearable device is in a first usage status, and when the at least one reflective signal does not have the peak frequency within the frequency processing range, the wearable device is in a second usage status.

13. The method as claimed in claim 10, further comprising:

setting a frequency processing range of the signal filter according to the physiological information.

14. The method as claimed in claim 13, wherein the step of performing the signal processing operation to the at least one reflective signal according to the at least one signal processing parameter through the controller comprises:

performing the signal processing operation to the at least one reflective signal within the frequency processing range.

15. The method as claimed in claim 14, wherein when the at least one reflective signal has a peak frequency within the frequency processing range, the wearable device is in a first usage status, and

when the at least one reflective signal does not have the peak frequency within the frequency processing range, the wearable device is in a second usage status.

16. The method as claimed in claim 13, wherein the step of adjusting the at least one signal processing parameter of the signal filter according to the physiological information through the controller comprises:

setting a signal gain of the signal filter according to the physiological information.

17. The method as claimed in claim 16, wherein the step of performing the signal processing operation to the at least one reflective signal according to the at least one signal processing parameter through the controller comprises:

performing the signal processing operation to the at least one reflective signal according to the signal gain.

18. The method as claimed in claim 16, wherein in the step of receiving the at least one reflective signal, the at least one reflective signal is received with different intensities when corresponding to a plurality of different test objects, and the method further comprises:

determining the physiological information of the test objects according to the different intensities of the at least one reflective signal.

19. The method as claimed in claim 18, wherein the at least one optical signal comprises a first optical signal and a second optical signal, respectively becoming a first reflective signal and a second reflective signal, when reflecting off the different test objects, wherein an intensity variation of the first reflective signal is greater than an intensity variation of the second reflective signal, and in the step of determining the physiological information of the test objects according to the different intensities of the at least one reflective signal, the physiological information of the test objects is determined according to the different intensities of the first reflective signal.

20. The method as claimed in claim 19, wherein a usage status of the wearable device is determined according to the different intensities of the second reflective signal.

21. A wearable device, comprising:

an optical sensor, adapted to emit at least one optical signal, and receive at least one reflective signal corresponding to the at least one optical signal, wherein the optical sensor receives the at least one reflective signal with different intensities when corresponding to a plurality of different test objects;

a controller, coupled to the optical sensor, and adapted to perform a signal processing operation to the at least one reflective signal according to at least one signal processing parameter, wherein the controller determines physiological information of the test objects according to the different intensities of the at least one reflective signal and adjusts the at least one signal processing parameter of a signal filter according to the physiological information, wherein the signal filter is adapted to perform the signal processing operation to the at least one reflective signal according to the at least one signal processing parameter, the at least one reflective signal comprises the physiological information,

wherein the controller sets a frequency processing range and a signal gain of the signal filter according to the physiological information, and the signal filter performs the signal processing operation to the at least one reflective signal within the frequency processing range according to the signal gain.