BIOSIGNAL MEASURING DEVICE, BIOSIGNAL MEASURING METHOD AND BIOSIGNAL PROGRAM

• US 20140142441A1
• Filed: 02/22/2013
• Published: 05/22/2014
• Est. Priority Date: 11/19/2012
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suzuki, Takuji, Fuke, Sawa, Nakayama, Kanako
• Granted Patent: US 9,706,931 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/346 Analysis of electrocardiograms

Abstract

A biosignal measuring device has a first information acquisition module, a second information acquisition module, a first calculation module, a second calculation module, a third calculation module, a heartbeat interval estimation module, a determination module, and an output module. The first information acquisition module acquires the pulse wave signal. The second information acquisition module acquires an electrocardiogram signal. The first calculation module calculates a pulse wave velocity based. The second calculation module determines a heartbeat interval. The third calculation module calculates a relationship between pulse wave velocity and the heartbeat interval. The heartbeat interval estimation module estimates an estimated heartbeat interval based on pulse wave velocity and calculated relationship. The determination module determines whether the position of the first and second information acquisition modules has changed based on the heartbeat interval and the estimated heartbeat interval. The output module outputs information.

Claims

1. A biosignal-measuring device, comprising:

a first information acquisition module configured to acquire a pulse wave signal from a subject at a first position;

a second information acquisition module configured to acquire an electrocardiogram signal from the subject at a second position different from the first position;

a first calculation module configured to calculate a pulse wave velocity based on signals acquired by the first information acquisition module and the second information acquisition module;

a second calculation module configured to calculate a heartbeat interval based on the signals acquired by the first information acquisition module and the second information acquisition module;

a third calculation module configured to calculate a relational expression between the pulse wave velocity and the heartbeat interval;

a heartbeat interval estimation module configured to estimate an estimated heartbeat interval based on the pulse wave velocity and the relational expression;

a determination module configured to determine whether a position of at least one of the first information acquisition module or the second information acquisition module has changed based on the heartbeat interval and the estimated heartbeat interval; and

an output module configured to output a notification based on the determination of the determination module.

2. The device according to claim 1, wherein the output module is configured output the notification as an audible signal.

3. The device according to claim 1, further comprising:

a correcting module configured to correct a parameter of the relational expression to estimate blood pressure using the pulse wave velocity if the determination module determines that the position of at least one of the first information acquisition module or the second information acquisition module has changed.

4. The device according to claim 1, wherein the third calculation module is further configured to calculate the relational expression between the feature value and the heartbeat interval for a period in which the first information acquisition module and the second information acquisition module are determined to be receiving signals in a stable manner.

5. The device according to claim 1, wherein the determination module is configured to determine the position of the first information acquisition module or the second information acquisition module has changed when a difference between the computed heartbeat interval and the estimated heartbeat interval is over a specified threshold for a specified time.

6. The device according to claim 5, wherein the determination module is configured to update the specified threshold based on the signals acquired by the first information acquisition module or the second information acquisition module.

7. The device according to claim 1, wherein the first information acquisition module includes a photoplethysmographic sensor.

8. The device according to claim 1, wherein the second information acquisition module includes a first and second electrode for acquiring a biosignal.

9. The device according to claim 1, wherein the first information acquisition module and the second information acquisition module are integrated on a single body unit.

10. The device according to claim 1, further comprising:

an adhesive unit configured to place the first and second information acquisition modules in contact with the subject.

11. The device according to claim 10, wherein the adhesive unit comprises a belt.

12. The device of claim 1, further comprising:

an input module configured to receive input from the subject.

13. A biosignal measurement method, comprising:

acquiring a pulse wave signal of a subject at a first position on the subject;

acquiring an electrocardiogram signal of the subject at a second position on the subject, the second position different from the first position;

calculating a pulse wave velocity using the pulse wave signal and the electrocardiogram signal;

calculating a heartbeat interval using the pulse wave signal and the electrocardiogram signal;

calculating a relational expression between the pulse wave velocity and the heartbeat interval;

estimating an estimated heartbeat interval based on the pulse wave velocity and the relational expression;

determining whether the first position and second position has changed using the calculated heartbeat interval and estimated heartbeat interval; and

outputting a notification based on the determination of whether the first position and second position has changed.

14. The method of claim 13, wherein the pulse wave signal is acquired using an optical electric pulse wave sensor.

15. The method of claim 13, wherein calculating the heartbeat interval includes calculating a feature value of the pulse wave velocity.

16. The method of claim 13, wherein calculating the relational expression involves a linear regression between a feature width value of the pulse wave velocity and the heartbeat interval.

17. The method of claim 13, further comprising:

updating a parameter of the relational expression from an initial parameter value based pulse wave velocity.

18. A non-transitory computer readable medium including a biosignal measuring program that when executed in a computer causes the computer to perform steps comprising:

acquiring a pulse wave signal of a subject at a first position on the subject;

acquiring an electrocardiogram signal of the subject at a second position on the subject, the second position different from the first position;

calculating a pulse wave velocity using the pulse wave signal and the electrocardiogram signal;

calculating a heartbeat interval using the pulse wave signal and the electrocardiogram signal;

calculating a relational expression between the pulse wave velocity and the heartbeat interval;

estimating an estimated heartbeat interval based on the pulse wave velocity and the relational expression;

determining whether the first position and second position has changed using the heartbeat interval and estimated heartbeat interval; and

outputting a notification based on the determination of whether the first position and second position has changed.

19. The non-transitory computer readable medium of claim 18, wherein calculating the relational expression involves a linear regression between a feature width value of the pulse wave velocity and the heartbeat interval.

20. The non-transitory computer readable medium of claim 18, wherein the steps further comprise:

outputting a blood pressure value calculated using the pulse wave velocity.