Heart rate monitoring method and apparatus

1 . A method, applied to an electronic device, and comprising:

determining that a wearer of the electronic device is a living body;

obtaining a first photoplethysmograph (PPG) signal;

determining a first heart rate and a confidence of the first heart rate according to the first PPG signal, wherein the confidence of the first heart rate is determined based on weight coefficients of M harmonic signals, wherein the M harmonic signals are determined according to the first PPG signal within a preset time, and M is an integer greater than or equal to 2, the determining the first heart rate and the confidence of the first heart rate comprising:

performing smoothing processing on the first PPG signal to obtain a smoothed PPG signal after the smoothing processing,

performing band-pass filtering on the smoothed PPG signal after the smoothing processing to obtain a second PPG signal, wherein the second PPG signal is in a target frequency band range,

performing Hilbert transform on the second PPG signal to obtain an analytic signal of the second PPG signal, wherein a derivative of a phase of the analytic signal is an instantaneous frequency,

performing notch processing on the analytic signal to obtain a third PPG signal, wherein the third PPG signal does not comprise a motion interference signal, and

filtering the third PPG signal through M filters to obtain the M harmonic signals;

outputting the first heart rate based on the confidence of the first heart rate meeting a preset confidence condition; and

displaying the first heart rate.

2 . The method according to claim 1 , further comprising:

displaying a second heart rate based on the confidence of the first heart rate not meeting the preset confidence condition, wherein the second heart rate is a heart rate that meets the preset confidence condition last time.

3 . The method according to claim 1 , further comprising:

calculating a corresponding weight coefficient of each of the M harmonic signals;

determining a corresponding confidence of the corresponding weight coefficient of each of the M harmonic signals to obtain M confidences; and

using a highest confidence among the M confidences as the confidence of the first heart rate.

4 . The method according to claim 3 , wherein the calculating the corresponding weight coefficient of each of the M harmonic signals comprises:

calculating a relative error of each harmonic signal relative to an ideal signal, wherein the ideal signal is obtained by multiplying a previous signal at a previous moment of a current moment by a phase at a next moment; and

dividing the relative error of each harmonic signal by a sum of relative errors of the M harmonic signals to obtain the corresponding weight coefficient of each of the M harmonic signals.

5 . The method according to claim 3 , wherein the determining the corresponding confidence of the corresponding weight coefficient of each of the M harmonic signals comprises:

determining the corresponding confidence corresponding to the corresponding weight coefficient of each of the M harmonic signals according to a confidence interval threshold, wherein the confidence interval threshold is determined by big data sample statistics.

6 . The method according to claim 1 , wherein the performing the smoothing processing on the first PPG signal to obtain a PPG signal after the smoothing processing comprises:

calculating, based on a signal abnormality of a current frame being identified, a sum of data of a previous frame of the current frame and data of a next frame of the current frame, and calculating an average value based on the sum of the data of the previous frame of the current frame and the data of the next frame of the current frame; and

using the average value as a value of the current frame after the smoothing processing.

7 . The method according to claim 1 , wherein the confidence of the first heart rate meeting the preset confidence condition comprises:

the confidence of the first heart rate being greater than a confidence threshold.

8 . The method according to claim 1 , further comprising:

storing a plurality of heart rate values whose confidences meet the preset confidence condition;

generating a heart rate curve based on the plurality of heart rate values; and

displaying the heart rate curve.

9 . An electronic device, comprising:

a processor; and

a memory coupled to the processor, the memory storing a computer program that, when executed by the processor, causes the electronic device to perform operations including:

determining that a wearer of the electronic device is a living body;

obtaining a first photoplethysmograph (PPG) signal;

determining a first heart rate and a confidence of the first heart rate according to the first PPG signal, wherein the confidence of the first heart rate is determined based on weight coefficients of M harmonic signals, wherein the M harmonic signals are determined according to the first PPG signal within a preset time, and M is an integer greater than or equal to 2, the determining the first heart rate and the confidence of the first heart rate comprising:

performing smoothing processing on the first PPG signal to obtain a smoothed PPG signal after the smoothing processing,

performing band-pass filtering on the smoothed PPG signal after the smoothing processing to obtain a second PPG signal, wherein the second PPG signal is in a target frequency band range,

performing Hilbert transform on the second PPG signal to obtain an analytic signal of the second PPG signal, wherein a derivative of a phase of the analytic signal is an instantaneous frequency,

performing notch processing on the analytic signal to obtain a third PPG signal, wherein the third PPG signal does not comprise a motion interference signal, and

filtering the third PPG signal through M filters to obtain the M harmonic signals;

outputting the first heart rate based on the confidence of the first heart rate meeting a preset confidence condition; and

displaying the first heart rate.

10 . The electronic device according to claim 9 , the operations further comprising:

displaying a second heart rate based on the confidence of the first heart rate not meeting the preset confidence condition, wherein the second heart rate is a heart rate that meets the preset confidence condition last time.

11 . The electronic device according to claim 9 , the operations further comprising:

calculating a corresponding weight coefficient of each of the M harmonic signals;

determining a corresponding confidence of the corresponding weight coefficient of each of the M harmonic signals to obtain M confidences; and

using a highest confidence among the M confidences as the confidence of the first heart rate.

12 . The electronic device according to claim 11 , wherein the calculating the corresponding weight coefficient of each of the M harmonic signals comprises:

calculating a relative error of each harmonic signal relative to an ideal signal, wherein the ideal signal is obtained by multiplying a previous signal at a previous moment of a current moment by a phase at a next moment; and

dividing the relative error of each harmonic signal by a sum of relative errors of the M harmonic signals to obtain the corresponding weight coefficient of each of the M harmonic signals.

13 . The electronic device according to claim 11 , wherein the determining the corresponding confidence of the corresponding weight coefficient of each of the M harmonic signals comprises:

determining the corresponding confidence corresponding to the corresponding weight coefficient of each of the M harmonic signals according to a confidence interval threshold, wherein the confidence interval threshold is determined by big data sample statistics.

14 . The electronic device according to claim 9 , wherein the performing the smoothing processing on the first PPG signal to obtain a PPG signal after the smoothing processing comprises:

calculating, based on a signal abnormality of a current frame being identified, a sum of data of a previous frame of the current frame and data of a next frame of the current frame, and calculating an average value based on the sum of the data of the previous frame of the current frame and the data of the next frame of the current frame; and

using the average value as a value of the current frame after the smoothing processing.

15 . The electronic device according to claim 9 , wherein the confidence of the first heart rate meeting the preset confidence condition comprises:

the confidence of the first heart rate being greater than a confidence threshold.

16 . The electronic device according to claim 9 , the operations further comprising:

storing a plurality of heart rate values whose confidences meet the preset confidence condition;

generating a heart rate curve based on the plurality of heart rate values; and

displaying the heart rate curve.

17 . A non-transitory computer-readable storage medium, storing a computer program that, when executed by an electronic device, causes the electronic device to perform operations including:

determining that a wearer of the electronic device is a living body;

obtaining a first photoplethysmograph (PPG) signal;

determining a first heart rate and a confidence of the first heart rate according to the first PPG signal, wherein the confidence of the first heart rate is determined based on weight coefficients of M harmonic signals, wherein the M harmonic signals are determined according to the first PPG signal within a preset time, and M is an integer greater than or equal to 2, the determining the first heart rate and the confidence of the first heart rate comprising:

calculating a corresponding weight coefficient of each of the M harmonic signals;

determining a corresponding confidence of the corresponding weight coefficient of each of the M harmonic signals to obtain M confidences; and

using a highest confidence among the M confidences as the confidence of the first heart rate, wherein the calculating the corresponding weight coefficient of each of the M harmonic signals comprises:

calculating a relative error of each harmonic signal relative to an ideal signal, wherein the ideal signal is obtained by multiplying a previous signal at a previous moment of a current moment by a phase at a next moment, and

dividing the relative error of each harmonic signal by a sum of relative errors of the M harmonic signals to obtain the corresponding weight coefficient of each of the M harmonic signals;

outputting the first heart rate based on the confidence of the first heart rate meeting a preset confidence condition; and

displaying the first heart rate.

18 . The non-transitory computer-readable storage medium according to claim 17 , the operations further comprising:

displaying a second heart rate based on the confidence of the first heart rate not meeting the preset confidence condition, wherein the second heart rate is a heart rate that meets the preset confidence condition last time.

19 . The non-transitory computer-readable storage medium according to claim 17 , the determining the first heart rate and the confidence of the first heart rate further comprising:

performing smoothing processing on the first PPG signal to obtain a smoothed PPG signal after the smoothing processing;

performing band-pass filtering on the smoothed PPG signal after the smoothing processing to obtain a second PPG signal, wherein the second PPG signal is in a target frequency band range;

performing Hilbert transform on the second PPG signal to obtain an analytic signal of the second PPG signal, wherein a derivative of a phase of the analytic signal is an instantaneous frequency;

performing notch processing on the analytic signal to obtain a third PPG signal, wherein the third PPG signal does not comprise a motion interference signal; and

filtering the third PPG signal through M filters to obtain the M harmonic signals.