System, method and device for detecting heart rate

1. A system for detecting a heart rate, the system comprising:

a sensing unit having a skin-facing surface removably securable to a user skin surface, the sensing unit having at least one sensor positioned to acquire a bio-signal from the skin surface; and

a controller operatively coupled to the sensing unit, the controller configured to:

capture an incoming bio-signal stream using the at least one sensor;

band-pass filter the incoming bio-signal stream within a predetermined passband to produce a filtered bio-signal stream;

pre-process the filtered bio-signal stream using a predictive model to determine a temporal segment of the filtered bio-signal stream in which heartbeat impulses are more easily detectable;

in the temporal segment, process the filtered bio-signal stream in a moving window to determine heartbeat signal portions when the filtered bio-signal stream has heartbeat impulse characteristics; and

determine time between adjacent heartbeat signal portions to compute the heart rate.

2. The system of claim 1 , wherein the heartbeat signal portions are determined by applying a detection algorithm to the filtered bio-signal stream.

3. The system of claim 2 , wherein the detection algorithm uses parameters of a supervised system trained using a plurality of captured bio-signal streams.

4. The system of claim 1 , wherein the heartbeat impulse characteristics comprise the signal portion having spatiotemporal properties indicative of a heartbeat impulse.

5. The system of claim 1 , wherein the heartbeat impulse characteristics comprise the signal portion exceeding a threshold value.

6. The system of claim 5 , wherein the threshold value is determined using an amplitude of the filtered bio-signal stream in the moving window.

7. The system of claim 6 , wherein the threshold value is determined as one of: a midpoint value, a mean value, a median value, a minimum value, a maximum value, a linear function, and a non-linear function of the amplitude of the preprocessed bio-signal stream in the moving window.

8. The system of claim 1 , wherein the time between adjacent signal portions is determined by:

segmenting the filtered bio-signal stream into heartbeat signal portions having heartbeat impulse characteristics and signal portions not having heartbeat impulse characteristics;

determining the time between adjacent impulses.

9. The system of claim 1 , wherein the passband has an upper cutoff frequency in a range between 10 Hz and 18 Hz.

10. The system of claim 1 , wherein the passband has a lower cutoff frequency in a range between 3 Hz and 5 Hz.

11. The system of claim 1 , wherein the sensors comprise electrodes.

12. The system of claim 11 , wherein the electrodes are passive electrodes.

13. The system of claim 11 , wherein the electrodes are active electrodes.

14. The system of claim 1 , wherein the at least one sensor comprises two sensors.

15. The system of claim 14 , wherein the sensors are positioned to acquire a differential bio-signal from the skin surface.

16. The system of claim 14 , where the sensors are positioned cross-body.

17. The system of claim 1 , wherein the filtered bio-signal stream comprises a quasi-periodic noise signal, and wherein pre-processing the filtered bio-signal stream comprises detecting the quasi-periodic noise signal.

18. The system of claim 17 , wherein the quasi-periodic noise signal comprises an EMG signal.

19. A method for detecting a heart rate using a sensing unit having at least one sensor positioned to acquire a bio-signal from the skin surface, the method comprising:

capturing an incoming bio-signal stream using the at least one sensor;

band-pass filtering the incoming bio-signal stream within a predetermined passband to produce a filtered bio-signal stream;

pre-processing the filtered bio-signal stream using a predictive model to determine a temporal segment of the filtered bio-signal stream in which heartbeat impulses are more easily detectable;

in the temporal segment, processing the filtered bio-signal stream in a moving window to determine heartbeat signal portions when the filtered bio-signal stream has heartbeat impulse characteristics; and

determining time between adjacent heartbeat signal portions to compute the heart rate.

20. A wearable device for detecting a heart rate, the device comprising:

a skin-facing surface removably securable to a user skin surface;

at least one sensor positioned to acquire a bio-signal from the skin surface; and

a controller operatively coupled to the at least one sensor, the controller configured to:

capture an incoming bio-signal stream using the at least one sensor;

band-pass filter the incoming bio-signal stream within a predetermined passband to produce a filtered bio-signal stream;

pre-process the filtered bio-signal stream using a predictive model to determine a temporal segment of the filtered bio-signal stream in which heartbeat impulses are more easily detectable;

in the temporal segment, processing the filtered bio-signal stream in a moving window to determine heartbeat signal portions when the filtered bio-signal stream has heartbeat impulse characteristics; and

determine time between adjacent heartbeat signal portions to compute the heart rate.