Method and apparatus for processing biosignal

• US 10,258,290 B2
• Filed: 06/15/2016
• Issued: 04/16/2019
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Chang Soon, Kwon, Ui Kun, Kim, Sang-joon, Yoon, Seungkeun, Lee, Jaechun, Choi, Changmok
• Primary Examiner(s): Hulbert, Amanda K
• Assistant Examiner(s): Edwards, Philip C
• Application Number:
  US15/182,956
• Publication Number:
  US 20170172514A1
• Time in Patent Office: 1,035 Days
• Field of Search: 600513
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G01R 23/16 Spectrum analysis; Fourier analysis
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06F 2218/04 Denoising

Abstract

A method of processing a biosignal includes estimating a time period from a time-domain biosignal, converting a biosignal corresponding to a time interval based on the time period to a frequency-domain signal, performing signal processing to remove a distortion component from the frequency-domain signal, and converting a processed frequency-domain signal obtained through the signal processing to a time-domain signal.

Claims

1. A processor-implemented biosignal processing method, comprising:

estimating a time period from a biosignal in a time-domain;

converting, based on the time period, a biosignal corresponding to a time interval of the biosignal to a frequency-domain signal;

performing signal processing by removing a determined distortion component from the frequency-domain signal; and

generating a reconstructed time-domain biosignal, as a reconstruction of the biosignal corresponding to the time interval, by converting a processed frequency-domain signal, obtained through the signal processing, to the time-domain.

2. The method of claim 1, wherein the biosignal comprises a form in which a basic waveform is repeated in the biosignal during the time period.

3. The method of claim 1, wherein the time interval corresponds to an integer multiple of the time period.

4. The method of claim 1, wherein the converting of the biosignal corresponding to the time interval to the frequency-domain signal comprises:

extracting the biosignal corresponding to the time interval from the biosignal; and

converting the extracted biosignal to the frequency-domain signal based on a determined number of times a basic waveform of the biosignal repeats during the time interval.

5. The method of claim 4, wherein the converting of the extracted biosignal to the frequency-domain signal comprises:

converting the extracted biosignal to the frequency-domain signal using at least one of a discrete Fourier transform (DFT) or a fast Fourier transform (FFT).

6. The method of claim 1, wherein the converting of the processed frequency-domain signal to the time-domain comprises:

converting the processed frequency-domain signal to the time-domains using at least one of an inverse DFT (IDFT) or an inverse FFT (IFFT).

7. A non-transitory computer-readable storage medium comprising stored program instructions configured to cause a processor to perform the method of claim 1.

8. The method of claim 1, wherein the biosignal is a waveform of a sensed physiological movement.

9. The method of claim 1, further comprising:

receiving the biosignal from an electrocardiogram (ECG), photoplethysmogram (PPG), or electromyogram (EMG) biosignal sensor.

10. The method of claim 1, wherein the performing of the signal processing comprises:

obtaining a first frequency component from the frequency-domain signal based on a determined number of times a basic waveform of the biosignal repeats during the time interval; and

removing, from the frequency-domain signal, a second frequency component corresponding to a remainder, excluding the first frequency component, of frequency components of the frequency-domain signal.

11. The method of claim 10, wherein the obtaining of the first frequency component comprises:

extracting, from the frequency-domain signal, frequency components corresponding to an integer multiple of the number of times the basic waveform of the biosignal repeats during the time interval.

12. The method of claim 10, wherein the first frequency component comprises frequency components corresponding to an integer multiple of an inverse value of the time period.

13. The method of claim 10, wherein the removing of the second frequency component further comprises:

removing complex conjugates of the second frequency components from the frequency-domain signal.

14. The method of claim 10, wherein the removing of the second frequency component comprises:

setting the second frequency component to zero.

15. The method of claim 14, wherein the removing of the second frequency component further comprises:

setting complex conjugates of the second frequency components in the frequency-domain signal to zero.

16. A processor-implemented biosignal processing method, comprising:

estimating a time period from a biosignal in a time-domain;

converting, based on the time period, a biosignal corresponding to a time interval of the biosignal to a frequency-domain signal;

performing signal processing to remove a distortion component from the frequency-domain signal; and

generating a reconstructed time-domain biosignal, as a reconstruction of the biosignal corresponding to the time interval, by converting a processed frequency-domain signal, obtained through the signal processing, to the time-domain,

wherein the performing of the signal processing comprises;

obtaining a first frequency component from the frequency-domain signal based on a determined number of times a basic waveform of the biosignal repeats during the time interval; and

removing, from the frequency-domain signal, a second frequency component corresponding to a remainder excluding the first frequency component.

17. The method of claim 16, wherein the obtaining of the first frequency component comprises:

extracting, from the frequency-domain signal, frequency components corresponding to an integer multiple of the number of times the basic waveform of the biosignal repeats during the time interval.

18. The method of claim 16, wherein the first frequency component comprises frequency components corresponding to an integer multiple of an inverse value of the time period.

19. The method of claim 16, wherein the removing of the second frequency component comprises:

setting, to a conjugate value, second frequency components at symmetrical frequencies in a frequency domain of the frequency-domain signal.

20. The method of claim 16, wherein the removing of the second frequency component comprises:

setting the second frequency component to zero.

21. A processor-implemented biosignal processing method, comprising:

receiving a biosignal in a time-domain from an electrocardiogram (ECG), photoplethysmogram (PPG), or electromyogram (EMG) biosignal sensor;

estimating a time period from the biosignal;

converting, based on the time period, a biosignal corresponding to a time interval of the biosignal to a frequency-domain signal;

performing signal processing to remove a distortion component from the frequency-domain signal; and

generating a reconstructed time-domain biosignal, as a reconstruction of the biosignal corresponding to the time interval, by converting a processed frequency-domain signal, obtained through the signal processing, to the time-domain.

22. An apparatus with biosignal processing, comprising:

a transmitting or receiving interface configured to receive a biosignal; and

a processor configured to

estimate a time period from the biosignal in a time-domain,

convert, based on the time period, a biosignal corresponding to a time interval of the biosignal to a frequency-domain signal,

perform signal processing to remove a determined distortion component from the frequency-domain signal, and

generate a reconstructed time-domain biosignal, as a reconstruction of the biosignal corresponding to the time interval, through a conversion of a processed frequency-domain signal, obtained through the signal processing, to the time-domain.

23. The apparatus of claim 22, wherein the biosignal comprises a form in which a basic waveform is repeated in the biosignal during the time period.

24. The apparatus of claim 22, wherein, for the performing of the signal processing, the processor is configured to obtain a first frequency component from the frequency-domain signal based on a determined number of times a basic waveform of the biosignal repeats during the time interval, and remove a second frequency component, corresponding to a remainder excluding the first frequency component, from the frequency-domain signal.

25. The apparatus of claim 24, wherein, for the obtaining of the first frequency component, the processor is configured to extract, from the frequency-domain signal, frequency components corresponding to an integer multiple of the number of times the basic waveform of the biosignal repeats during the time interval.

26. The apparatus of claim 24, wherein the first frequency component comprises frequency components corresponding to an integer multiple of an inverse value of the time period.

27. The apparatus of claim 24, wherein, for the removing of the second frequency component, the processor is further configured to remove complex conjugates of the second frequency components from the frequency-domain signal.

28. The apparatus of claim 24, wherein, for the removing of the second frequency component, the processor is configured to set the second frequency component to zero.

29. The apparatus of claim 22, wherein the time interval corresponds to an integer multiple of the time period.

30. The apparatus of claim 22, wherein, for the converting of the biosignal corresponding to the time interval, the processor is configured to extract the biosignal corresponding to the time interval from the biosignal, and convert the extracted biosignal to the frequency-domain signal based on a determined number of times a basic waveform of the biosignal repeats during the time interval.

31. The apparatus of claim 30, wherein, for the converting of the extracted biosignal, the processor is configured to convert the extracted biosignal to the frequency-domain signal using at least one of a discrete Fourier transform (DFT) or a fast Fourier transform (FFT).

32. The apparatus of claim 22, wherein, for the converting of the processed frequency-domain signal to the time interval, the processor is configured to convert the processed frequency-domain signal to the time-domain using at least one of an inverse DFT (IDFT) or an inverse FFT (IFFT).

33. A processor-implemented biosignal processing method, comprising:

sensing a periodic physiological movement as a biosignal in a time-domain;

extracting a plurality of periods from the biosignal;

converting the extracted plurality of periods to a frequency-domain signal;

isolating, based on a number of the plurality of periods, a reconstruction component from a distortion component of the frequency-domain signal; and

generating a reconstructed time-domain biosignal, as a reconstruction of the extracted plurality of periods, by converting the reconstruction component to the time-domain.

34. A biosignal processing system, the system comprising:

a sensor configured to sense a periodic physiological movement as a biosignal in a time-domain; and

a processor configured to;

extract a plurality of periods from the biosignal;

convert the extracted plurality of periods to a frequency-domain signal;

isolate, based on a number of the plurality of periods, a reconstruction component from a distortion component of the frequency-domain signal; and

generate a reconstructed time-domain biosignal, as a reconstruction of the extracted plurality of periods, by converting the reconstruction component to the time-domain.