Coupling and method for detecting heart rate

• US 9,999,360 B2
• Filed: 06/10/2009
• Issued: 06/19/2018
• Est. Priority Date: 06/11/2008
• Status: Active Grant

• Current Assignee: Suunto Oy (Anta International Group Holdings Ltd.)
• Original Assignee: Suunto Oy (Anta International Group Holdings Ltd.)
• Inventors: Martikka, Mikko, Lindman, Erik, Akkila, Jari
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Bays, Pamela M
• Application Number:
  US12/482,004
• Publication Number:
  US 20090312657A1
• Time in Patent Office: 3,296 Days
• Field of Search: 600300, 600508, 600518, 600519, 600521, 607 9, 607 25
• 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 5/6831 Straps, bands or harnesses
• 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 5/7239 using differentiation including higher order derivatives

Abstract

The invention relates to a coupling and method in a heart-rate measuring apparatus. The coupling in the heart-rate measuring apparatus (10) comprises means (1, 2, 3, 4, 5) for measuring heart rate and means for wireless data transmission (7). According to the invention, the heart-rate measuring device (10) comprises means (1, 2, 3, 4, 5) implemented by analog electronics for defining the maximum value of the heart-rate signal, or a parameter proportional to it.

Claims

1. Coupling in a heart-rate measuring apparatus, comprising:

one or more electrodes for receiving a heart rate signal;

analog circuitry configured to store a reference level proportional to a maximum value of the heart rate signal received from the electrodes;

a peak detector configured to compare the heart rate signal received from the electrodes with the stored reference level from the analog circuitry; and

a transmitter for wirelessly transmitting heart rate data based on output from the peak detector.

2. Coupling according to claim 1, wherein the analog circuitry that stores the reference level is connected directly to a microcontroller of the heart-rate measuring apparatus.

3. Coupling according to claim 1, further comprising analog circuitry configured to confirm the detection of a peak, using a time derivative of a descending edge of the heart rate signal.

4. Coupling according to claim 3, wherein the analog circuitry configured to confirm the detection of a peak acquires a time stamp of a peak by sending an interrupt to a microcontroller.

5. Coupling according to claim 1, further comprising circuitry for accepting a peak detected by the peak detector as a heartbeat moment, if a new peak is not detected after a predefined period.

6. Coupling according to claim 1, further comprising circuitry for accepting a maximum on a condition, wherein a new maximum is at least a previous maximum-y mV, where y is approximately 0.5.

7. Coupling according to claim 1, further comprising circuitry for resetting the reference level to a minimum value, if a peak is not detected by the peak detector during a predefined interval.

8. Coupling according to claim 1, wherein the transmitter is configured to transmit heart-rate data equipped with identifier information.

9. Coupling according to claim 1, wherein the transmitter is configured to transmit time stamps based on the output of the peak detector.

10. Coupling according to claim 1, further comprising a memory.

11. Coupling according to claim 1, further comprising a zero detector configured to detect a zero crossing in the heart rate signal received from the electrodes.

12. Coupling according to claim 1, further comprising a microcontroller configured to process heart rate data.

13. The coupling according to claim 1, wherein the analog circuitry configured to store a reference level proportional to a maximum value of the heart rate signal comprises a transistor and a capacitor.

14. Method in a heart-rate measuring apparatus, comprising:

receiving a heart rate signal;

storing, using analog circuitry, a reference level proportional to a maximum value of the received heart rate signal; and

detecting a maximum in the received heart rate signal when the received signal is greater than the reference level.

15. Method according to claim 14, further comprising confirming, using analog circuitry, the detection of a maximum with the aid of a time derivative of a descending edge of the heart rate signal.

16. Method according to claim 14, further comprising acquiring a time stamp of the maximum by sending an interrupt to a microcontroller.

17. Method according to claim 14, wherein the detected maximum is accepted as the moment of a heartbeat, if, after the detection of the maximum, a new maximum is not detected during a predefined period.

18. Method according to claim 14, wherein the maximum is accepted on a condition, by which a new maximum is at least a previous maximum -y mV, where y is approximately 0.5.

19. Method according to claim 14, wherein the reference level is reset to its minimum value, if a new maximum is not detected during a predefined interval.

20. Method according to claim 14, wherein the heart rate data transmitted from the heart-rate measuring device is equipped with identifier information.

21. Method according to claim 14, wherein heart rate data is transmitted from the heart-rate measuring apparatus as time stamps relating to the heartbeats.

22. Method according to claim 14, wherein information is recorded in the heart-rate measuring apparatus.

23. Method of claim 14, further comprising detecting a zero crossing of the received heart rate signal based on a reference.

24. Heart-rate measuring system, comprising:

a heart-rate measuring device, which includes one or more electrodes for receiving a heart rate signal, analog circuitry configured to store a reference level proportional to a maximum value of the heart rate signal received from the electrodes, and circuitry for wirelessly transmitting heart rate data, and

a receiver apparatus, which comprises circuitry for receiving heart-rate data over a wireless transmission channel and analysing or displaying the received heart-rate data, or for displaying analysis results.

25. The heart-rate measuring system according to claim 24, wherein the analog circuitry configured to store a reference level proportional to a maximum value of the heart rate signal comprises a transistor and a capacitor.