System, method and device for detecting heart rate

• US 9,770,179 B2
• Filed: 03/26/2015
• Issued: 09/26/2017
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Trenda Innovations, Inc.
• Original Assignee: GestureLogic Inc.
• Inventors: Etemad, Seyed Ali, MacEachern, Leonard, Klibanov, Mark, Houmanfar, Roshanak
• Primary Examiner(s): Patton, Amanda
• Assistant Examiner(s): EDWARDS, PHILIP CHARLES
• Application Number:
  US14/669,635
• Publication Number:
  US 20150272457A1
• Time in Patent Office: 915 Days
• Field of Search: 600509
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/346 Analysis of electrocardiograms
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence

Abstract

A system, method and device are described for detecting a heart rate. A sensing unit can have a skin-facing surface that is removably securable to a user'"'"'s skin surface and include at least one sensor positioned to acquire a bio-signal from the skin surface. A controller can be configured to capture a bio-signal stream using the at least one sensor and generate a preprocessed bio-signal stream by band-pass filtering the captured bio-signal stream with a predetermined passband. The controller can also be configured to determine, in a moving window, heartbeat signal portions when the preprocessed bio-signal stream has heartbeat impulse characteristics and determine the time between adjacent heartbeat signal portions to compute the heart rate.

Claims

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.