Pulse wave data analyzing method, system, and program product

• US 20070123787A1
• Filed: 10/05/2006
• Published: 05/31/2007
• Est. Priority Date: 10/06/2005
• Status: Active Grant

• Current Assignee: Konica Minolta Sensing, Inc. (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Sensing, Inc. (Konica Minolta Inc.)
• Inventors: Nagai, Yoshiroh, Kitajima, Kazumi, Tsukamoto, Yasumasa, Fukunami, Masatake
• Granted Patent: US 7,727,158 B2
• Time in Patent Office: Days
• US Class Current: 600/509
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval

Abstract

There is provided a pulse wave data analyzing method for extracting vital information out of pulse wave data concerning a living body. The method comprises a noise removal step of: detecting bottom values and peak values along a time axis in a time-series manner out of pulse wave data obtained by sequentially measuring a pulse wave of a subject for a predetermined period; making pairs with respect to the bottom values and the peak values adjacent to each other on the time axis to obtain bottom-to-peak amplitude values along the time axis, the bottom-to-peak amplitude value being a difference between the bottom value and the peak value in each of the pairs; and comparing each set of the two bottom-to-peak amplitude values adjacent to each other along the time axis to remove the bottom value and the peak value relating to the smaller bottom-to-peak amplitude value in the each set as a noise, if a ratio of the one of the two bottom-to-peak amplitude values to the other one of the two bottom-to-peak amplitude values is larger than a predetermined value.

Claims

1. A pulse wave data analyzing method for extracting vital information out of pulse wave data concerning a living body, the method comprising a noise removal step of:

detecting bottom values and peak values along a time axis in a time-series manner out of pulse wave data obtained by sequentially measuring a pulse wave of a subject for a predetermined period;

making pairs with respect to the bottom values and the peak values adjacent to each other on the time axis to obtain bottom-to-peak amplitude values along the time axis, the bottom-to-peak amplitude value being a difference between the bottom value and the peak value in each of the pairs; and

comparing each set of the two bottom-to-peak amplitude values adjacent to each other along the time axis to remove the bottom value and the peak value relating to the smaller bottom-to-peak amplitude value in the each set as a noise, if a ratio of the one of the two bottom-to-peak amplitude values to the other one of the two bottom-to-peak amplitude values is larger than a predetermined value.

2. The pulse wave data analyzing method according to claim 1, further comprising a step of:

obtaining peak-to-peak intervals or bottom-to-bottom intervals corresponding to electrocardiogram RR-intervals based on pulse wave data obtained by executing the noise removal step.

3. The pulse wave data analyzing method according to claim 1, further comprising a step of:

obtaining bottom-to-peak amplitude values based on pulse wave data obtained by executing the noise removal step.

4. The pulse wave data analyzing method according to claim 1, further comprising a step of:

executing a moving averaging process with respect to the pulse wave data prior to detecting the bottom values and the peak values out of the pulse wave data.

5. The pulse wave data analyzing method according to claim 1, wherein

the noise removal step is executed one or more times with respect to pulse wave data obtained by executing the noise removal step for the first time.

6. The pulse wave data analyzing method according to claim 5, wherein

a threshold value of the amplitude value ratio used in judging whether the bottom value and the peak value are to be removed as the noise is changed at least once in repeating the noise removal step.

7. A pulse wave data analyzing system for extracting vital information out of pulse wave data concerning a living body, the system comprising:

a pulse wave detector for obtaining pulse wave information concerning a subject at a predetermined sampling frequency to acquire pulse wave data in association with a time axis; and

a data analyzer for executing a noise removal process to analyze the pulse wave data,

the data analyzer including

an inflection point detector for detecting bottom values and peak values along the time axis in a time-series manner out of the pulse wave data,

an amplitude value detector for making pairs with respect to the bottom values and the peak values adjacent to each other on the time axis to obtain bottom-to-peak amplitude values along the time axis, the bottom-to-peak amplitude value being a difference between the bottom value and the peak value in each of the pairs, and

a noise remover for comparing each set of the two bottom-to-peak amplitude values adjacent to each other along the time axis to remove the bottom value and the peak value relating to the smaller bottom-to-peak amplitude value in the each set as a noise, if a ratio of the one of the two bottom-to-peak amplitude values to the other one of the two bottom-to-peak amplitude values is larger than a predetermined value.

8. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer includes an interval calculator for obtaining peak-to-peak intervals or bottom-to-bottom intervals corresponding to electrocardiogram RR-intervals based on pulse wave data obtained by executing the noise removal by the noise remover.

9. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer includes an amplitude value calculator for obtaining bottom-to-peak amplitude values, as diagnostic information, based on pulse wave data obtained by executing the noise removal by the noise remover.

10. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer includes a moving averaging processor for executing a moving averaging process with respect to the pulse wave data obtained by the pulse wave detector.

11. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer controls the inflection point detector, the amplitude value detector, and the noise remover to execute the noise removal process one or more times with respect to pulse wave data obtained by executing the noise removal process for the first time.

12. The pulse wave data analyzing system according to claim 11, wherein

the noise remover changes a threshold value of the amplitude value ratio used in judging whether the bottom value and the peak value are to be removed as the noise at least once in repeating the noise removal process.

13. The pulse wave data analyzing system according to claim 7, further comprising:

a display section for displaying a data analysis result by the data analyzer, wherein

the pulse wave detector, the data analyzer, and the display section are mounted on a device removably attachable to the subject.

14. The pulse wave data analyzing system according to claim 7, further comprising:

a storage section for storing therein the pulse wave data obtained by the pulse wave detector;

a first device including the pulse wave detector and the storage section, the first device being removably attachable to the subject; and

a second device including the data analyzer, the second device being communicable with the first device to acquire the pulse wave data stored in the storage section.

15. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer analyzes the pulse wave data on a real-time basis, and controls a display section to display the pulse wave information obtained by the analysis thereof.

16. The pulse wave data analyzing system according to claim 7, wherein

the data analyzer includes a storage section for storing the analyzed pulse wave information therein.

17. A pulse wave data analyzing program product for extracting vital information out of pulse wave data concerning a living body, the program product comprising:

a program which causes a data analyzer for analyzing the pulse wave data to execute;

obtaining pulse wave information concerning a subject at a predetermined sampling frequency to acquire pulse wave data in association with a time axis;

detecting bottom values and peak values along a time axis in a time-series manner out of the pulse wave data;

making pairs with respect to the bottom values and the peak values adjacent to each other on the time axis to obtain bottom-to-peak amplitude values along the time axis, the bottom-to-peak amplitude value being a difference between the bottom value and the peak value in each of the pairs; and

comparing each set of the two bottom-to-peak amplitude values adjacent to each other along the time axis to remove the bottom value and the peak value relating to the smaller bottom-to-peak amplitude value in the each set as a noise, if a ratio of the one of the two bottom-to-peak amplitude values to the other one of the two bottom-to-peak amplitude values is larger than a predetermined value; and

a signal bearing media bearing the program.