Wearable Device, And Heart Rate Tracking Method And Apparatus Thereof

1 . A method of heart rate tracking for a wearable device, comprising:

obtaining, by a processor, a photo pethysmo graphic (PPG) signal of the wearable device within a preset time;

obtaining, by the processor, a frequency spectrum corresponding to the PPG signal by a short-time Fourier transform of the PPG signal;

generating, by the processor, a curve cluster according to the frequency spectrum; and

in response to determining a curve that meets a preset condition in the curve cluster, acquiring a jumped heart rate according to the curve that meets the preset condition to track the heart rate.

2 . The method according to claim 1 , wherein generating, by the processor, the curve cluster according to the frequency spectrum comprises:

performing amplitude normalization on the frequency spectrum;

obtaining a point pair of frequency and amplitude by searching for a local peak for the normalized frequency spectrum;

in response to determining a current moment being greater than zero, pairing a point pair at the current moment with a point pair at a previous moment; and

generating the curve cluster according to the two paired point pairs after pairing is successful, wherein the two paired point pairs comprise the point pair at the current moment and the point pair at the previous moment.

3 . The method according to claim 2 , wherein generating the curve cluster according to the two paired point pairs comprises:

in response to determining the point pair at the previous moment existing in a first curve, adding the point pair at the current moment to the first curve; or

in response to determining that the point pair at the previous moment is not in the first curve:

generating a second curve according to the point pair at the previous moment and the point pair at the current moment; and

generating the curve cluster by acquiring the first curve and the second curve within the preset time.

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

after obtaining the point pair of frequency and amplitude by searching for the local peak for the normalized frequency spectrum, in response to determining an amplitude of the point pair smaller than a preset amplitude, deleting the point pair whose amplitude is smaller than the preset amplitude.

5 . The method according to claim 1 , wherein determining the curve that meets the preset condition in the curve cluster comprises:

selecting from all curves of the curve cluster a curve where a point pair at a last moment is consistent with a point pair at a current moment to generate a curve set; and

in response to determining the curve set being not empty, selecting a curve that meets the preset condition from the curve set;

wherein the preset condition is that at least one curve in the curve set has a length larger than a preset length, and no other curves exist in a preset frequency range of the at least one curve within a preset period before the current moment.

6 . The method according to claim 5 , wherein in response to determining the curve that meets the preset condition in the curve cluster, acquiring the jumped heart rate according to the curve that meets the preset condition to track the heart rate, comprises:

selecting from the curves that meet the preset condition a curve with a largest length; and

determining a frequency at a last moment of the curve with the largest length as the jumped heart rate to track the heart rate.

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

before obtaining the PPG signal of the wearable device:

collecting an optical signal through an optical sensor, wherein the optical signal comprises the PPG signal and an acceleration signal; and

filtering out the acceleration signal from the optical signal by a filtering algorithm to obtain the PPG signal.

8 . An apparatus for heart rate tracking, comprising:

a processor; and

a memory for storing instructions executable by the processor;

wherein the processor is configured to execute the instructions stored in the memory to:

obtain a photo pethysmo graphic (PPG) signal within a preset time;

obtain a frequency spectrum corresponding to the PPG signal by a short-time Fourier transform of the PPG signal;

generate a curve cluster according to the frequency spectrum; and

in response to determining a curve that meets a preset condition in the curve cluster, acquire a jumped heart rate according to the curve that meets the preset condition to track the heart rate.

9 . The apparatus according to claim 8 , wherein the instructions to generate the curve cluster according to the frequency spectrum comprise instructions to:

perform amplitude normalization on the frequency spectrum;

obtain a point pair of frequency and amplitude by searching for a local peak for the normalized frequency spectrum;

in response to determining a current moment being greater than zero, pair a point pair at the current moment with a point pair at a previous moment; and

generate the curve cluster according to the two paired point pairs after pairing is successful, wherein the two paired point pairs comprise the point pair at the current moment and the point pair at the previous moment.

10 . The apparatus according to claim 9 , wherein the instructions to generate the curve cluster according to the two paired point pairs comprise instructions to:

in response to determining the point pair at the previous moment existing in a first curve, add the point pair at the current moment to the first curve; or

in response to determining that the point pair at the previous moment is not in the first curve:

generate a second curve according to the point pair at the previous moment and the point pair at the current moment; and

generate the curve cluster by acquiring the first curve and the second curve within the preset time.

11 . The apparatus according to claim 9 , further comprising:

after obtaining the point pair of frequency and amplitude by searching for the local peak for the normalized frequency spectrum, in response to determining an amplitude of the point pair smaller than a preset amplitude, delete the point pair whose amplitude is smaller than the preset amplitude.

12 . The apparatus according to claim 8 , wherein the instructions to determine the curve that meets the preset condition in the curve cluster comprise instructions to:

select from all curves of the curve cluster a curve where a point pair at a last moment is consistent with a point pair at a current moment to generate a curve set; and

in response to determining the curve set being not empty, select a curve that meets the preset condition from the curve set;

wherein the preset condition is that at least one curve in the curve set has a length larger than a preset length, and no other curves exist in a preset frequency range of the at least one curve within a preset period before the current moment.

13 . The apparatus according to claim 12 , wherein the instructions to in response to determining the curve that meets the preset condition in the curve cluster, acquire the jumped heart rate according to the curve that meets the preset condition to track the heart rate, further comprise instructions to:

select from the curves that meet the preset condition a curve with a largest length; and

determine a frequency at a last moment of the curve with the largest length as the jumped heart rate to track the heart rate.

14 . The apparatus according to claim 8 , wherein the instructions further comprise instructions to:

before obtaining the PPG signal of the wearable device:

collect an optical signal through an optical sensor, wherein the optical signal comprises the PPG signal and an acceleration signal; and

filter out the acceleration signal from the optical signal by a filtering algorithm to obtain the PPG signal.

15 . The apparatus according to claim 8 , wherein the apparatus comprises a wearable device, and the instructions to obtain the PPG signal within the preset time comprise instructions to:

obtain the PPG signal of the wearable device within the preset time.

16 . A non-transitory computer-readable storage medium, having stored therein instructions that, when executed by a processor of an electronic device, causes the electronic device to perform the method according to claim 1 .

17 . The non-transitory computer-readable storage medium according to claim 16 , wherein generating, by the processor, the curve cluster according to the frequency spectrum comprises:

performing amplitude normalization on the frequency spectrum;

obtaining a point pair of frequency and amplitude by searching for a local peak for the normalized frequency spectrum;

in response to determining a current moment being greater than zero, pairing a point pair at the current moment with a point pair at a previous moment; and

generating the curve cluster according to the two paired point pairs after pairing is successful, wherein the two paired point pairs comprise the point pair at the current moment and the point pair at the previous moment.

18 . The non-transitory computer-readable storage medium according to claim 17 , wherein generating the curve cluster according to the two paired point pairs comprises:

in response to determining the point pair at the previous moment existing in a first curve, adding the point pair at the current moment to the first curve; or

in response to determining that the point pair at the previous moment is not in the first curve:

generating a second curve according to the point pair at the previous moment and the point pair at the current moment; and

generating the curve cluster by acquiring the first curve and the second curve within the preset time.

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

after obtaining the point pair of frequency and amplitude by searching for the local peak for the normalized frequency spectrum, in response to determining an amplitude of the point pair smaller than a preset amplitude, deleting the point pair whose amplitude is smaller than the preset amplitude.

20 . The non-transitory computer-readable storage medium according to claim 16 , wherein determining the curve that meets the preset condition in the curve cluster comprises:

selecting from all curves of the curve cluster a curve where a point pair at a last moment is consistent with a point pair at a current moment to generate a curve set; and

in response to determining the curve set being not empty, selecting a curve that meets the preset condition from the curve set;

wherein the preset condition is that at least one curve in the curve set has a length larger than a preset length, and no other curves exist in a preset frequency range of the at least one curve within a preset period before the current moment.