Method for detecting heart rate and systems thereof

• US 20060287606A1
• Filed: 06/21/2005
• Published: 12/21/2006
• Est. Priority Date: 06/21/2005
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hong, Di-Ann, Xiao, Weimin, Mohamed, Magdi A., Grajales, Liliana
• Application Number:
  US11/157,640
• Publication Number:
  US 20060287606A1
• Time in Patent Office: Days
• US Class Current: 600/528
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 7/00 Instruments for auscultation

Abstract

A method for detecting heart rate, the method including the steps of: receiving (100) a heart activity signal at an input of a Q-filter processor that includes at least a first and a second Q-filter; removing noise (300) from the heart activity signal using the Q-filter processor to generate a filtered heart activity signal; detecting (400) a heart activity pattern, that includes at least a first S1 or QRS at a first time and a second S1 or QRS at a second time, from the filtered heart activity signal; and determining (500) a heart rate value based on the time interval between the first S1 and the second S1 or between the first QRS and the second QRS.

Claims

1. A method for detecting heart rate comprising the steps of:

receiving a heart sound signal at an input of a Q-filter processor that comprises at least a first and a second Q-filter;

removing noise from the heart sound signal using the Q-filter processor to generate a filtered heart sound signal;

detecting a heart sound pattern comprising at least a first S1 at a first time and a second S1 at a second time, from the filtered heart sound signal; and

determining a heart rate value based on the time interval between the first S1 and the second S1.

2. The method of claim 1, wherein the heart sound pattern is a dual-peak heart sound pattern that further comprises a first S2 at a third time between the first and second times and a second S2 at a fourth time after the second time.

3. The method of claim 1, wherein the step of detecting a heart sound pattern comprises the steps of:

configuring a set of parameters;

detecting a maximum amplitude of the filtered heart sound signal;

detecting a plurality of peaks in the filtered heart sound signal, each having an amplitude greater than a threshold value that is based on the maximum amplitude;

detecting a first heart beat from the plurality of peaks that includes the first S1; and

detecting a second heart beat from the plurality of peaks that includes the second S1.

4. The method of claim 3, wherein the step of configuring a set of parameters includes setting a sampling frequency and at least one threshold value and determining a window size.

5. The method of claim 1, wherein the step of removing noise from the heart sound signal to generate a filtered heart sound signal comprises the steps of:

determining a value of a variable parameter λ

;

determining a density generator vector f={f¹, f², . . . , fⁿ};

constructing a q-measure based on the variable parameter λ and

the vector f; and

filtering the heart sound signal based on the q-measure.

6. A method for detecting heart rate comprising the steps of:

receiving a heart electrical signal at an input of a Q-filter processor that comprises at least a first and a second Q-filter;

removing noise from the heart electrical signal using the Q-filter processor to generate a filtered heart electrical signal;

detecting a heart electrical pattern comprising at least a first QRS at a first time and a second QRS at a second time, from the filtered heart electrical signal; and

determining a heart rate value based on the time interval between the first QRS and the second QRS.

7. The method of claim 6, wherein the heart electrical pattern is a dual-peak heart electrical pattern that further comprises a first T at a third time between the first and second times and a second T at a fourth time after the second time.

8. The method of claim 6, wherein the step of detecting a heart electrical pattern comprises the steps of:

configuring a set of parameters;

detecting a maximum amplitude of the filtered heart electrical signal;

detecting a plurality of peaks in the filtered heart electrical signal having an amplitude greater than a threshold that is based on the maximum amplitude;

detecting a first heart beat from the plurality of peaks that includes the first QRS; and

detecting a second heart beat from the plurality of peaks that includes the second QRS.

9. The method of claim 8, wherein the step of configuring a set of parameters includes setting a sampling frequency and at least one threshold value and determining a window size.

10. The method of claim 6, wherein the step of removing ambient noise from the heart electrical signal to generate a filtered heart electrical signal comprises the steps of:

determining a value of a variable parameter λ

;

determining a density generator vector f={f¹, f², . . . , fⁿ};

constructing a q-measure based on the variable parameter λ and

the vector f; and

filtering the heart electrical signal based on the q-measure.

11. Apparatus for heart rate detection from a heart activity signal comprising:

a Q-filter processor comprising at least a first and a second Q-filter coupled together for receiving a heart activity signal and removing noise from the heart activity signal to generate a filtered heart activity signal;

a heart pattern recognition device for detecting a heart activity pattern comprising at least a first indicia at a first time and a second indicia at a second time, from the filtered heart activity signal; and

a decision making device for determining a heart rate value based on the time interval between the first indicia and the second indicia.

12. The apparatus of claim 11, wherein:

the first indicia is one of a first S1 and a first QRS;

the second indicia is one of a second S1 and a second QRS; and

the heart rate is based on one of the interval between the first and second S1 and the interval between the first and second QRS.

13. The apparatus of claim 11, wherein the apparatus comprises at least one of an acoustic sensor system, an electrical sensor system, and optical sensor system, a portable sensor system, a wearable portable sensor system and a wireless sensor system.

14. The apparatus of claim 11, wherein the first and second Q-filters are coupled one of in series and in parallel.

15. The apparatus of claim 11, wherein the first and second Q-filters are non-linear signal processing filters.

16. The apparatus of claim 11, wherein the first Q-filter has a first window size, and the second Q-filter has a second window size that is larger than the first window size.

17. The apparatus of claim 11, wherein the Q-filter processor further comprises at least one other Q-filter and the Q-filters are coupled together at least one of in series and in parallel.

18. The apparatus of claim 11, wherein the first and second Q-filters comprise logic circuitry and a memory coupled together to generate a q-measure based on a variable parameter λ

and a vector f and to output a filtered signal based on the q-measure.