Bio-signal quality assessment apparatus and method and bio-signal measurement parameter optimization apparatus and method

1. A bio-signal quality assessment apparatus comprising: a processor configured to:

determine a moving average of a measured bio-signal;

divide the measured bio-signal into sections;

compare each of a plurality of values of a plurality of bio-signal samples of the measured bio-signal with the determined moving average;

determine a number of bio-signal samples having a value greater than the determined moving average in each of the sections as a result of the comparison;

determine a variance or a standard deviation of the determined number of bio-signal samples in each of the sections;

determine a quality of the measured bio-signal as being a first quality when the variance or the standard deviation of the determined number of bio-signal samples is greater than or equal to a threshold value;

determine the quality of the measured bio-signal as being a second quality when the variance or the standard deviation of the determined number of bio-signal samples is less than the threshold value; and

adjust, based on the quality of the determined bio-signal, any one or any combination of an amount of an emitted light, an amplification gain of a measuring of the bio-signal, and a cancellation current of a measuring of the bio-signal;

wherein a signal-to-noise ratio (SNR) of the measured bio-signal is positively correlated with the variance or the standard deviation of the determined number of bio-signal samples.

2. The bio-signal quality assessment apparatus of claim 1 , wherein the bio-signal is a photoplethysmography signal.

3. The bio-signal quality assessment apparatus of claim 1 , wherein the moving average is an exponentially weighted moving average.

4. The bio-signal quality assessment apparatus of claim 1 , wherein the processor is further configured to assess that the quality of the measured bio-signal is better as the determined variance or the determined standard deviation is larger than the threshold value.

5. The bio-signal quality assessment apparatus of claim 1 , further comprising a bio-signal measurer configured to measure the bio-signal.

6. The bio-signal quality assessment apparatus of claim 5 , wherein the bio-signal measurer comprises:

a light source configured to emit the light onto a subject; and

a photodetector configured to measure the bio-signal by detecting light that is reflected or scattered from the subject.

7. The bio-signal quality assessment apparatus of claim 1 , further comprising a data receiver configured to receive data of the bio-signal from an external device.

8. A bio-signal quality assessment method comprising:

determining a moving average of a measured bio-signal;

dividing the measured bio-signal into sections;

comparing each of a plurality of values of a plurality of bio-signal samples of the measured bio-signal with the determined moving average;

determining a number of bio-signal samples having a value greater than the determined moving average in each of the sections as a result of the comparison;

determining a variance or a standard deviation of the determined number of bio-signal samples in each of the sections;

determining a quality of the measured bio-signal as being a first quality when the variance or the standard deviation of the determined number of bio-signal samples is greater than or equal to a threshold value;

determining the quality of the measured bio-signal as being a second quality when the variance or the standard deviation of the determined number of bio-signal samples is less than a threshold value; and

adjusting, based on the quality of the determined bio-signal, any one or any combination of an amount of an emitted light, an amplification gain of a measuring of the bio-signal, and a cancellation current of a measuring of the bio-signal,

wherein a signal-to-noise ratio (SNR) of the measured bio-signal is positively correlated with the variance or the standard deviation of the determined number of bio-signal samples.

9. The bio-signal quality assessment method of claim 8 , wherein the assessing of the quality of measured the bio-signal further comprises assessing that the quality of the measured bio-signal is better as the determined variance or the determined standard deviation is larger than the threshold value.

10. The bio-signal quality assessment method of claim 8 , wherein the bio-signal is a photoplethysmography signal.

11. The bio-signal quality assessment method of claim 8 , wherein the moving average is an exponentially weighted moving average.

12. The bio-signal quality assessment method of claim 8 , further comprising measuring the bio-signal.

13. The bio-signal quality assessment method of claim 12 , further comprising emitting the light onto a subject,

wherein the measuring of the bio-signal comprises measuring the bio-signal by detecting light that is reflected or scattered from the subject.

14. The bio-signal quality assessment method of claim 8 , further comprising receiving data of the bio-signal from an external device.

15. A bio-signal measurement parameter optimization apparatus comprising:

a bio-signal measurer configured to:

emit light onto a subject; and

measure a bio-signal by detecting light that is reflected or scattered from the subject; and

a processor configured to:

determine a moving average of the measured bio-signal;

divide the measured bio-signal into sections;

compare each of a plurality of values of a plurality of bio-signal samples of the measured bio-signal with the determined moving average;

determine a number of bio-signal samples having a value greater than the determined moving average in each of the sections as a result of the comparison;

determine a variance or a standard deviation of the determined number of bio-signal samples in each of the sections;

determine a quality of the measured bio-signal as being a first quality when the variance or the standard deviation of the determined number of bio-signal samples is greater than or equal to a threshold value; and

determine the quality of the measured bio-signal as being a second quality when the variance or the standard deviation of the determined number of bio-signal samples is less than the threshold value, wherein a signal-to-noise ratio (SNR) of the measured bio-signal is positively correlated with the variance or the standard deviation of the determined number of bio-signal samples, and

adjust, based on the determined quality of the measured bio-signal, any one or any combination of an amount of the emitted light, an amplification gain of the bio-signal measurer, and a cancellation current of the bio-signal measurer.

16. The bio-signal measurement parameter optimization apparatus of claim 15 , wherein the bio-signal is a photoplethysmography signal.

17. The bio-signal measurement parameter optimization apparatus of claim 15 , wherein the moving average is an exponentially weighted moving average.

18. The bio-signal measurement parameter optimization apparatus of claim 15 , wherein the processor is further configured to, in response to the determined quality of the measured bio-signal being the second quality, adjust any one or any combination of the amount of the emitted light, the amplification gain, and the cancellation current.

19. The bio-signal measurement parameter optimization apparatus of claim 18 , wherein the processor is further configured to:

in response to the determined quality of the measured bio-signal being greater than the threshold value, determine whether a number of times of measuring the bio-signal corresponds to a predetermined value;

in response to the number of times of measuring the bio-signal being determined to not correspond to the predetermined value, measure another bio-signal;

in response to the number of times of measuring the bio-signal being determined to correspond to the predetermined value, determine bio-signal quality indices of a plurality of bio-signals that are measured, and determine an average of the determined bio-quality indices; and

in response to the determined average of the bio-signal quality indices being less than or equal to a threshold value, adjust any one or any combination of the amount of the emitted light, the amplification gain, and the cancellation current.

20. A bio-signal measurement parameter optimization method comprising:

emitting light onto a subject;

measuring a bio-signal by detecting light that is reflected or scattered from the subject;

determining a moving average of the measured bio-signal;

dividing the measured bio-signal into sections;

comparing each of a plurality of values of a plurality of bio-signal samples of the measured bio-signal with the determined moving average;

determining a number of bio-signal samples having a value greater than the determined moving average in each of the sections as a result of the comparison;

determining a variance or a standard deviation of the determined number of bio-signal samples in each of the sections;

determining a quality of the measured bio-signal as being a first

quality when the variance or the standard deviation of the determined number of bio-signal samples is greater than or equal to a threshold value;

determining the quality of the measured bio-signal as being a second quality when the variance or the standard deviation of the determined number of bio-signal samples is less than the threshold value, wherein a signal-to-noise ratio (SNR) of the measured bio-signal is positively correlated with the variance or the standard deviation of the determined number of bio-signal samples; and

adjusting, based on the quality of the determined bio-signal, any one or any combination of an amount of the emitted light, an amplification gain of the measuring of the bio-signal, and a cancellation current of the measuring of the bio-signal.

21. The bio-signal measurement parameter optimization method of claim 20 , wherein the adjusting comprises, in response to the determined quality of the measured bio-signal being the second quality, adjust any one or any combination of the amount of the emitted light, the amplification gain, and the cancellation current.