Cardionpulmonary function evaluating apparatus and cardionpulmonary function evaluating method

• US 9,901,267 B2
• Filed: 03/04/2015
• Issued: 02/27/2018
• Est. Priority Date: 03/14/2014
• Status: Active Grant

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: Konno, Norihito, Hajiri, Makoto
• Primary Examiner(s): KAHELIN, MICHAEL WILLIAM
• Application Number:
  US14/638,612
• Publication Number:
  US 20150257656A1
• Time in Patent Office: 1,091 Days
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

A cardiopulmonary function evaluating apparatus includes: an electrocardiogram measuring unit which is configured to measure an electrocardiogram of a subject; a photoplethysmogram detecting unit which is configured to detect a photoplethysmogram of the subject; a heart rate calculating unit which is configured to calculate a heart rate (HR) of the subject based on the electrocardiogram; a PWTT calculating unit which is configured to calculate a pulse wave transmission time (PWTT) of the subject based on the electrocardiogram and the photoplethysmogram; an SV calculating unit which is configured to calculate a stroke volume (SV) of the subject based on the heart rate and the pulse wave transmission time; and an outputting unit which is configured to output a state related to the stroke volume of the subject based on the stroke volume that is calculated by the SV calculating unit.

Claims

1. A cardiopulmonary function evaluating apparatus comprising:

an electrocardiogram measuring unit which is configured to measure an electrocardiogram of a subject based on signals from at least one electrocardiogram electrode;

a photoplethysmogram detecting unit which is configured to detect a photoplethysmogram of the subject; and

at least one processor configured to;

calculate a heart rate (HR) of the subject based on the electrocardiogram;

calculate a pulse wave transmission time (PWTT) of the subject based on the electrocardiogram and the photoplethysmogram;

calculate a stroke volume (SV) of the subject based on the heart rate (HR) and the pulse wave transmission time (PWTT);

output a state related to the stroke volume (SV) of the subject based on the calculated stroke volume (SV),

acquire a temporal change of the stroke volume (SV) in one exercise a plurality of times; and

superimposedly display a plurality of the temporal change of the stroke volume (SV) in the one exercise.

2. The cardiopulmonary function evaluating apparatus according to claim 1, wherein the processor is further configured to

evaluate a cardiopulmonary ability of the subject, based on the calculated stroke volume (SV) and an index value related to the stroke volume (SV);

and

output a result of the evaluation of the cardiopulmonary ability as the state related to the stroke volume (SV) of the subject.

3. The cardiopulmonary function evaluating apparatus according to claim 1, wherein the index value includes at least one of a history value of the calculated stroke volume (SV), and a statistical value of stroke volumes (SV) related to the subject.

4. The cardiopulmonary function evaluating apparatus according to claim 3, wherein the processor is further configured to calculate a difference (Δ

esSV) between the current stroke volume (SV) and the history value which is acquired at a predetermined timing.

5. The cardiopulmonary function evaluating apparatus according to claim 3, wherein the processor is further configured to:

refer to the history value, and

calculate an amount of change (d(esSV)/dt) of the current stroke volume (SV).

6. The cardiopulmonary function evaluating apparatus according to claim 3, wherein the processor is further configured to compare and evaluate the statistical value and the current stroke volume (SV).

7. A cardiopulmonary function evaluating method comprising:

measuring an electrocardiogram of a subject;

detecting a photoplethysmogram of the subject;

calculating a heart rate (HR) of the subject based on the electrocardiogram;

calculating a pulse wave transmission time (PWTT) of the subject based on the electrocardiogram and the photoplethysmogram;

calculating a stroke volume (SV) of the subject based on the heart rate (HR) and the pulse wave transmission time (PWTT); and

outputting a state related to the stroke volume (SV) of the subject based on the calculated stroke volume (SV);

acquiring a temporal change of the stroke volume (SV) in one exercise a plurality of times; and

superimposedly displaying a plurality of the temporal change of the stroke volume (SV) in the one exercise.

8. The cardiopulmonary function evaluating method according to claim 7, further comprising:

evaluating a cardiopulmonary ability of the subject, based on the calculated stroke volume (SV) and an index value related to the stroke volume (SV), and

outputting a result of the evaluation of the cardiopulmonary ability as the state related to the stroke volume (SV) of the subject.

9. The cardiopulmonary function evaluating method according to claim 8, wherein the index value includes at least one of a history value of the calculated stroke volume (SV), and a statistical value of stroke volumes (SV) related to the subject.

10. The cardiopulmonary function evaluating method according to claim 9, further comprising calculating a difference (Δ

esSV) between the current stroke volume (SV) and the history value which is acquired at a predetermined timing.

11. The cardiopulmonary function evaluating method according to claim 9, further comprising calculating an amount of change (d(esSV)/dt) of the current stroke volume (SV).

12. The cardiopulmonary function evaluating method according to claim 9, further comprising comparing and evaluating the statistical value and the current stroke volume (SV).