METHOD FOR DETERMINING A HEARTBEAT RATE

• US 20110213263A1
• Filed: 02/26/2010
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Abandoned Application

• Current Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Haartsen, Jacobus Cornelis
• Application Number:
  US12/713,781
• Publication Number:
  US 20110213263A1
• Time in Patent Office: Days
• US Class Current: 600/528
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• 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 5/6815 Ear
• CPC Class Codes: A61B 5/6817 Ear canal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 7/00 Instruments for auscultation

Abstract

A method for determining a heartbeat rate of a user from an acoustic heartbeat signal, a heartbeat rate measuring device, and a mobile device are described.

Claims

1. A method for determining a heartbeat rate of a user from an acoustic heartbeat signal, the method comprising:

detecting the acoustic heartbeat signal in an ear of the user,

sampling the heartbeat signal with a predefined sampling rate,

providing a plurality of heartbeat rate values,

correlating the sampled heartbeat signal with each of the plurality of heartbeat rate values, and

determining the heartbeat rate value with the best matching correlation as the heartbeat rate.

2. The method according to claim 1, wherein providing the plurality of heartbeat rate values is based on the predefined sampling rate.

3. The method according to claim 1, comprising low pass filtering of the detected heartbeat signal.

4. The method according to claim 3, wherein the low pass filtering comprises a cut-off frequency in a range from 4 Hz to 10 Hz.

5. The method according to claim 1, comprising forming an absolute value of the detected heartbeat signal.

6. The method according to claim 1, wherein correlating the sampled heartbeat signal with each of the plurality of heartbeat rate values comprises for each heartbeat rate value:

providing a plurality of cumulation values, wherein the number of the plurality of cumulation values is defined by the heartbeat rate value and the predefined sampling rate, and

adding a sample value of the sampled heartbeat signal to a cumulation value of the plurality of cumulation values, wherein consecutive sampling values are added to consecutively and cyclicly addressed cumulation values.

7. The method according to claim 6, wherein determining the heartbeat rate value with the best matching correlation comprises:

determining for each heartbeat rate value a difference value between a minimum cumulation value and a maximum cumulation value of the plurality of cumulation values relating to the heartbeat rate value, and

defining the heartbeat rate value with a maximum difference value as the heartbeat rate value with the best matching correlation.

8. The method according to claim 6, wherein the number of the plurality of cumulation values for each heartbeat rate value is defined by a ratio of the predefined sampling rate to the heartbeat rate value.

9. The method according to claim 6, wherein before adding the sample value to the cumulation value the cumulation value is reduced by a predetermined factor.

10. The method according to claim 9, wherein the value of the predetermined factor is in the range from 0.8 to 0.95.

11. The method according to claim 1, wherein the value of the predefined sampling rate is in the range from 10 to 200 Hz.

12. A heartbeat rate measuring device, comprising:

a microphone adapted to detect an acoustic heartbeat signal of a user in an ear of the user,

a sampling unit adapted to sample the heartbeat signal with a predefined sampling rate, and

a correlation unit providing a plurality of heartbeat rate values, the correlation unit being adapted to correlate the sampled heartbeat signal with each of the plurality of heartbeat rate values, and to determine the heartbeat rate value with the best matching correlation.

13. The heartbeat rate measuring device according to claim 12, wherein the plurality of heartbeat rate values is based on the predefined sampling rate.

14. The heartbeat rate measuring device according to claim 12, comprising a low pass filter adapted to filter the detected heartbeat signal.

15. The heartbeat rate measuring device according to claim 14, wherein the low pass filter has a cut-off frequency in a range from 4 Hz to 10 Hz.

16. The heartbeat rate measuring device according to claim 12, comprising an absolute value unit adapted to form an absolute value of the detected heartbeat signal.

17. The heartbeat rate measuring device according to claim 12, wherein the correlation unit is adapted to:

provide for each heartbeat rate value a plurality of cumulation values, wherein the number of the plurality of cumulation values is defined by the heartbeat rate value and the predefined sampling rate, and

add a sample value of the sampled heartbeat signal to a cumulation value of the plurality of cumulation values for each heartbeat rate value, wherein consecutive sampling values are added to consecutively and cyclicly addressed cumulation values.

18. The heartbeat rate measuring device according to claim 17, wherein the correlation unit is adapted to

determine for each heartbeat rate value a difference value between a minimum cumulation value and a maximum cumulation value of the plurality of cumulation values relating to the heartbeat rate value, and

define the heartbeat rate value with a maximum difference value as the heartbeat rate value with the best matching correlation.

19. The heartbeat rate measuring device according to claim 17, wherein the number of the plurality of cumulation values for each heartbeat rate value is defined by a ratio of the predefined sampling rate to the heartbeat rate value.

20. The heartbeat rate measuring device according to claim 17, wherein the correlation unit is adapted to reduce the cumulation value by a predetermined factor before adding the sample value to the cumulation value.

21. The heartbeat rate measuring device according to claim 20, wherein the value of the predetermined factor is in the range from 0.8 to 0.95.

22. The heartbeat rate measuring device according to claim 12, wherein the value of the predefined sampling rate is in the range from 10 to 200 Hz.

23. A mobile device comprising a heartbeat rate measuring device, the heartbeat rate measuring device, comprising:

a microphone adapted to detect an acoustic heartbeat signal of a user in an ear of the user,

a sampling unit adapted to sample the heartbeat signal with a predefined sampling rate, and

a correlation unit providing a plurality of heartbeat rate values, the correlation unit being adapted to correlate the sampled heartbeat signal with each of the plurality of heartbeat rate values, and to determine the heartbeat rate value with the best matching correlation.

24. The mobile device according to claim 23, wherein the mobile device comprises a device selected from the group comprising a mobile phone, a personal digital assistant, a mobile navigation system, a mobile media player, and a mobile computer.