Pulsimeter, control method for pulsimeter, wristwatch information device, control program, and recording medium

• US 7,144,375 B2
• Filed: 09/03/2003
• Issued: 12/05/2006
• Est. Priority Date: 09/06/2002
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kosuda, Tsukasa
• Primary Examiner(s): Nasser, Robert L.
• Assistant Examiner(s): Toth, Karen E
• Application Number:
  US10/654,257
• Publication Number:
  US 20040106872A1
• Time in Patent Office: 1,189 Days
• Field of Search: None
• US Class Current: 600/503
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/681 Wristwatch-type devices

Abstract

A frequency analyzer carries out a frequency analysis on a pulse wave signal output from a pulse wave detector. A candidate extractor extracts candidate spectrum peaks from a frequency analysis result of the frequency analyzer. A phase variation calculator calculates variations in phase angle of each of the extracted candidate spectrum peaks, and a spectrum peak selector selects a target spectrum peak from among the extracted candidate spectrum peaks based on their respective variations in phase angle. A pulse rate is calculated using the target spectrum peak.

Claims

1. A pulsimeter comprising:

a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal;

a frequency analyzer for carrying out a frequency analysis on the pulse wave signal;

a candidate extractor for extracting candidate spectrum peaks based on the frequency analysis result of the frequency analyzer;

a phase angle information detector for detecting phase angle information of each of the extracted candidate spectrum peaks;

a spectrum peak selector for selecting a target spectrum peak for calculating a pulse rate from among the extracted candidate spectrum peaks based on their respective phase angle information; and

a pulse rate calculator for calculating the pulse rate based on the target spectrum peak.

2. The pulsimeter according to claim 1, wherein

the phase angle information includes at least one of information regarding variations in phase angle and variations in phase angle difference per unit time;

and

the spectrum peak selector selects as the target spectrum peak the candidate spectrum peak exhibiting the greatest variation in phase angle or the greatest variation in phase angle difference per unit time.

3. A pulsimeter comprising:

a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal;

a body motion detector that has a body motion sensor and outputs a body motion signal;

a frequency analyzer for carrying out a frequency analysis on each of the pulse wave signal and the body motion signal;

a preliminary extractor for extracting preliminary spectrum peaks of the pulse wave signal and the body motion signal based on the frequency analysis result of the frequency analyzer;

a candidate extractor for extracting candidate spectrum peaks by taking the difference of the preliminary spectrum peaks of the pulse wave signal and the body motion signal;

a target spectrum peak selector for identifying as higher magnitude spectrum peaks any candidate spectrum peak greater than a predefined reference amount, and for selecting as a target spectrum peak the highest of the identified higher magnitude spectrum peaks;

a phase angle information detector for determining phase angle information, of the extracted candidate spectrum peaks if the target spectrum peak selector identifies no higher magnitude spectrum peaks;

wherein said target spectrum peak selector selects said target spectrum peak among the candidate spectrum peaks based on the phase angle information if no higher magnitude spectrum peaks are identified; and

a pulse rate calculator for calculating a pulse rate on the basis of said target spectrum peak.

4. The pulsimeter according to claim 3, wherein said target spectrum peak selector includes a first peak selector and a second peak selector;

said first peak selector being effective selecting as said target spectrum peak the highest of the identified higher magnitude spectrum peaks; and

said second peak selector being effective for selecting said target spectrum peak from among the candidate spectrum peaks based on the phase angle information if no higher magnitude spectrum peaks are identified.

5. The pulsimeter according to claim 3, wherein

the phase angle information includes information regarding variations in phase angle or variations in phase angle difference per unit time;

and

the target spectrum peak selector selects as the target spectrum peak the candidate spectrum peak exhibiting the greatest variation in phase angle or the greatest variation in phase angle difference per unit time.

6. A control method for a pulsimeter provided with a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal, comprising:

a frequency analysis step for carrying out a frequency analysis on the pulse wave signal;

a candidate extraction step for extracting candidate spectrum peaks based on the result of the frequency analysis;

a phase angle information detection step for detecting phase angle information for each of the extracted candidate spectrum peaks;

a spectrum peak selection step for selecting a target spectrum peak for calculating a pulse rate from among the extracted candidate spectrum peaks based on their respective phase angle information; and

a pulse rate calculation step for calculating a pulse rate based on the target spectrum peak.

7. The control method for a pulsimeter according to claim 6, wherein

the phase angle information includes at least one of information regarding variations in phase angle and variations in phase angle difference per unit time;

and

the spectrum peak selection step selects as the target spectrum peak the candidate spectrum peak exhibiting the greatest variation in phase angle or the greatest variation in phase angle difference per unit time.

8. A control method for a pulsimeter provided with a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal and a body motion detector that has a body motion sensor and outputs a body motion signal, comprising:

a frequency analysis step for carrying out a frequency analysis on each of the pulse wave signal and the body motion signal;

a preliminary extraction step for extracting preliminary spectrum peaks of the pulse wave signal and the body motion signal based on the result of the frequency analysis;

a candidate identification step for identifying candidate spectrum peaks by taking the difference of the preliminary spectrum peaks of the pulse wave signal and the body motion signal, and for identifying as higher magnitude spectrum peaks any candidate spectrum peak greater than a predefined reference amount;

a phase angle information detection step for determining phase angle information of extracted candidate spectrum peaks if no higher magnitude spectrum peaks are identified;

a target spectrum peak selection step for selecting a target spectrum peak, wherein the highest of the identified higher magnitude spectrum peaks is selected as said target spectrum peak or if no higher magnitude spectrum peaks are identified then the target spectrum peak is selected from among the candidate spectrum peaks based on their phase angle information; and

a pulse rate calculation step for calculating a pulse rate based on the target spectrum peak.

9. The control method for a pulsimeter according to claim 8, wherein said target spectrum peak includes a first peak selection sub-step and a second peak selection sub-step;

wherein said first peak selection sub-step includes selecting the highest of the identified higher magnitude spectrum peaks as said target spectrum peak; and

wherein said second peak selection sub-step includes selecting the target spectrum peak from among the candidate spectrum peaks based on their phase angle information if no higher magnitude spectrum peaks are identified.

10. The control method for a pulsimeter according to claim 8, wherein said phase angle information detection step is skipped if higher magnitude spectrum peaks are identified in said candidate identification step.

11. The control method for a pulsimeter according to claim 8, wherein

the phase angle information includes information regarding variations in phase angle or variations in phase angle difference per unit time ;

and

the target spectrum peak selection step selects as said target spectrum peak the candidate spectrum peak exhibiting the greatest variation in phase angle or the greatest variation in phase angle difference per unit time if no higher magnitude spectrum peaks are identified.

12. A wristwatch information device comprising:

a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal; and

a main unit for attachment to an arm of a body, wherein the main unit includes;

a frequency analyzer for carrying out a frequency analysis on the pulse wave signal;

a candidate extractor for extracting candidate spectrum peaks based on the frequency analysis result of the frequency analyzer;

a phase angle information detector for detecting phase angle information of each of the extracted candidate spectrum peaks;

a spectrum peak selector for selecting a target spectrum peak for calculating a pulse rate from among the extracted candidate spectrum peaks based on their respective phase angle information;

a pulse rate calculator for calculating the pulse rate based on the target spectrum peak; and

a display unit for displaying the calculated pulse rate.

13. A wristwatch information device, comprising:

a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal; and

a main unit for attachment to an arm of a body, wherein the main unit includes;

a body motion detector that has a body motion sensor and outputs a body motion signal;

a frequency analyzer for carrying out a frequency analysis on each of the pulse wave signal and the body motion signal;

a preliminary extractor for extracting preliminary spectrum peaks of the pulse wave signal and the body motion signal based on the frequency analysis result of the frequency analyzer;

a candidate extractor for extracting candidate spectrum peaks by taking the difference of preliminary spectrum peaks of the pulse wave signal and the body motion signal spectra;

a target spectrum peak selector for identifying as higher magnitude spectrum peaks any candidate spectrum peak greater than a predefined reference amount, and for selecting as a target spectrum peak the highest of the identified higher magnitude spectrum peaks;

a phase angle information detector for determining phase angle information of the extracted candidate spectrum peaks if the target spectrum peak selector identifies no higher magnitude spectrum peaks;

wherein said target spectrum peak selector selects said target spectrum peak from among the candidate spectrum peaks based on the phase angle information if no higher magnitude spectrum peaks are identified;

a pulse rate calculator for calculating a pulse rate on the basis of said target spectrum peak; and

a display unit for displaying the calculated pulse rate.

14. The wristwatch information device of claim 13, wherein said spectrum peak selector includes a first target peak selector and a second target peak selector;

said first target peak selector being effective for selecting as said target spectrum peak the highest of the identified higher magnitude spectrum peaks;

said second target peak selector being effective for selecting said target spectrum peak from among the candidate spectrum peaks based on the phase angle information if no higher magnitude spectrum peaks are identified.

15. A control program for controlling, by a computing device, a pulsimeter equipped with a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal, said control program causing:

frequency analysis on the pulse wave signal;

extraction of candidate spectrum peaks based on the result of the frequency analysis;

detection of phase angle informationfor each of the extracted candidate spectrum peaks;

selection of a target spectrum peak for calculating a pulse rate from among the candidate spectrum peaks based on the phase angle information; and

calculation of a pulse rate based on the target spectrum peak.

16. A computer-readable recording medium in which the control program of claim 15 is recorded.

17. A control program for controlling, by a computing device, a pulsimeter provided with a pulse wave detector that has a pulse wave sensor and outputs a pulse wave signal and a body motion detector that has a body motion sensor and outputs a body motion signal;

said control program causing;

frequency analysis on each of the pulse wave signal and the body motion signal;

extraction of preliminary spectrum peaks corresponding to the pulse wave signal and the body motion signal based on the result of the frequency analysis;

identification of candidate spectrum peaks by taking the difference of the preliminary spectrum peaks of the pulse wave signal and the body motion signal and identifying as higher magnitude spectrum peaks any candidate spectrum peaks greater than a predefined reference amount;

determination of phase angle information for the extracted candidate spectrum peaks if no higher magnitude spectrum peaks are identified;

selection of a target spectrum peak, wherein the highest of the identified higher magnitude spectrum peaks is selected as said target spectrum peak or if no higher magnitude spectrum peaks are identified then the target spectrum peak is selected from among the candidate spectrum peaks based on their phase angle information; and

calculation of a pulse rate on the basis of the target spectrum peak.

18. A computer-readable recording medium in which the control program of claim 17 is recorded.