Feature extraction apparatus and method for biometric information detection, biometric information detection apparatus, and wearable device

• US 10,667,757 B2
• Filed: 01/24/2017
• Issued: 06/02/2020
• Est. Priority Date: 09/20/2016
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Chang Soon, Kwon, Ui Kun, Kim, Young Soo
• Primary Examiner(s): Kundu, Sujoy K
• Assistant Examiner(s): Stifter, Jr., Terence E
• Application Number:
  US15/413,940
• Publication Number:
  US 20180078215A1
• Time in Patent Office: 1,225 Days
• Field of Search: None
• 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 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

A feature extraction apparatus configured to perform biometric information detection includes a bio-signal obtainer configured to acquire a bio-signal; and a processor configured to decompose a waveform of the acquired bio-signal into component pulses and extract a feature for the biometric information detection based on characteristic points of the component pulses.

Claims

1. A feature extraction apparatus configured to perform biometric information detection, the feature extraction apparatus comprising:

a sensor configured to acquire a bio-signal; and

a processor configured to;

adjust an asymmetry factor for component pulses of the bio-signal;

decompose a waveform of the acquired bio-signal into the component pulses based on adjusting the asymmetry factor; and

extract a feature for the biometric information detection based on characteristic points of the component pulses.

2. The feature extraction apparatus of claim 1, wherein the processor is configured to:

obtain a subsequent component pulse based on a new bio-signal generated based on one of the component pulses.

3. The feature extraction apparatus of claim 2, wherein the processor is configured to:

estimate a given component pulse to be decomposed, among the component pulses, based on the waveform of the bio-signal and thereby generate an estimation result; and

generate the given component pulse based on the estimation result.

4. The feature extraction apparatus of claim 3, wherein the processor is configured to, when the given component pulse is generated, eliminate the generated component pulse from the bio-signal, and when a number of generated component pulses is smaller than a pre-set number, estimate another subsequent component pulse based on another new bio-signal generated by eliminating the generated component pulse.

5. The feature extraction apparatus of claim 3, wherein the processor is configured to model a component pulse waveform function based on the waveform of the acquired bio-signal and estimate parameters of the component pulse waveform function.

6. The feature extraction apparatus of claim 5, wherein the processor is configured to model the component pulse waveform function to be bilaterally asymmetric with respect to a time axis, based on a Gaussian waveform function and the asymmetry factor.

7. The feature extraction apparatus of claim 6, wherein the processor is configured to, when the given component pulse is estimated based on a current bio-signal and the asymmetry factor, adjust the asymmetry factor based on a new bio-signal generated by eliminating the estimated component pulse from the current bio-signal, and re estimate the given component pulse based on the current bio-signal and the adjusted asymmetry factor.

8. The feature extraction apparatus of claim 7, wherein the processor is configured to adjust the asymmetry factor based on a determination that a mean time period of the eliminated component pulse is smaller than a time period at a peak point.

9. The feature extraction apparatus of claim 1, wherein the processor is configured to extract the feature for the biometric information detection based on characteristic points which include one or more of time, an amplitude, a standard deviation, and an offset of the decomposed component pulses.

10. The feature extraction apparatus of claim 1, wherein the sensor is configured to acquire the bio-signal by emitting light onto a user'"'"'s skin and detecting light returning from the user'"'"'s skin.

11. The feature extraction apparatus of claim 1, further comprising a communication interface configured to receive the bio-signal from a biometric information detection apparatus, forward the bio-signal to the sensor and transmit a result of processing based on the received bio-signal to the biometric information detection apparatus.

12. A feature extraction method for biometric information detection, the feature extraction method comprising:

acquiring a bio-signal;

adjusting an asymmetry factor for component pulses of the No-signal;

decomposing a waveform of the acquired bio-signal into the component pulses based on adjusting the asymmetry factor; and

extracting a feature for the biometric information detection based on characteristic points of each of the component pulses.

13. The feature extraction method of claim 12, wherein the decomposing comprises obtaining a subsequent component pulse based on a new bio-signal generated based on one of the component pulses.

14. The feature extraction method of claim 13, wherein the decomposing comprises:

estimating a given component pulse to be decomposed, among the component pulses, based on the waveform of the bio-signal; and

generating the given component pulse based on the estimation result.

15. The feature extraction method of claim 14, further comprising, when the given component pulse is generated, eliminating the generated component pulse from the bio-signal,

wherein the estimating of the given component pulse comprises, when a number of generated component pulses is smaller than a pre-set number, estimating another subsequent component pulse based on another new bio-signal generated by eliminating the generated component pulse.

16. The feature extraction method of claim 14, wherein the estimating of the given component pulse comprises modeling a component pulse waveform function based on the waveform of the bio-signal and estimating parameters of the component pulse waveform function.

17. The feature extraction method of claim 16, wherein the modeling of the component pulse waveform function comprises modeling the component pulse waveform function to be bilaterally asymmetric with respect to a time axis, based on a Gaussian waveform function and the asymmetry factor.

18. The feature extraction method of claim 17, further comprising adjusting the asymmetry factor for a waveform of the given component pulse to be estimated.

19. The feature extraction method of claim 18, wherein the adjusting of the asymmetry factor comprises:

estimating the given component pulse based on the bio-signal and the asymmetry factor;

eliminating the estimated component pulse from the bio-signal;

comparing a mean time period of the bio-signal from which the component pulse is eliminated with a time period at a peak point, and,

in response to determining that the mean time period is smaller than the time period at a peak point, adjusting the asymmetry factor and re-estimating the given component pulse.

20. A biometric information detection apparatus comprising:

a sensor configured to emit light onto a user'"'"'s skin, detect the light reflecting from the user'"'"'s skin, and measure a bio-signal based on the detected light; and

a processor configured to adjust an asymmetry factor for component pulses of the bio-signal, decompose a waveform of the bio-signal into the component pulses based on adjusting the asymmetry factor, extract a feature of the bio-signal based on characteristic points of the component pulses, and detect biometric information based on the feature.

21. The biometric information detection apparatus of claim 20, wherein the processor is further configured to obtain a subsequent component pulse based on a new bio-signal generated based on one of the component pulses.

22. The biometric information detection apparatus of claim 21, wherein the processor is further configured to model a component pulse waveform function which is asymmetric with respect to a time axis, based on a Gaussian waveform function and the asymmetry factor, and decompose the bio-signal into the component pulses based on the modeled component pulse waveform function.

23. The biometric information detection apparatus of claim 20, wherein the processor is further configured to extract the feature based on characteristic points which include one or more of time, an amplitude, a standard deviation, and an offset of the component pulses.

24. The biometric information detection apparatus of claim 20, further comprising a communication interface configured to transmit the measured bio-signal to a feature extraction apparatus and receive, from the feature extraction apparatus, at least one of one or more additional component pulses decomposed based on the bio-signal, characteristic points of each of the additional component pulses, and a feature extracted based on the characteristic points.

25. The biometric information detection apparatus of claim 20, wherein the biometric information comprises one or more of blood pressure, a vascular age, a degree of arterial stiffness, an aortic pressure waveform, a stress index, and a degree of fatigue.

26. A wearable device comprising:

a main body;

a sensor provided in the main body and configured to emit light onto a user'"'"'s skin, detect the light reflecting from the user'"'"'s skin, and measure a bio-signal based on the detected light;

a processor provided in the main body and configured to acquire the bio-signal by controlling the sensor, adjust an asymmetry factor for component pulses of the bio-signal, decompose a waveform of the acquired bio-signal into the component pulses based on adjusting the asymmetry factor, extract a feature based on characteristic points of the component pulses, detect biometric information using the extracted feature, and generate a processing result based on the detected biometric information; and

a display provided in the main body and configured to display the processing result of the processor.

27. The wearable device of claim 26, wherein the display comprises a first section configured to display the detected biometric information or changes in the detected biometric information.

28. The wearable device of claim 27, wherein the display further comprises a second section configured to display component pulses used to detect biometric information which is selected from the first section.

29. The wearable device of claim 28, wherein the display is configured to display a mark in the first section for indicating the detected biometric information or the biometric information selected from the first section.

30. The wearable device of claim 26, further comprising a communication interface provided in the main body and configured to establish a connection with an external device for communication and transmit the processing result of the processor to the external device via the connection.