BIO-INFORMATION MEASUREMENT DEVICE AND METHOD THEREFOR

• US 20160270708A1
• Filed: 09/10/2014
• Published: 09/22/2016
• Est. Priority Date: 10/03/2013
• Status: Abandoned Application

• Current Assignee: Konica Minolta Inc.
• Original Assignee: Konica Minolta Inc.
• Inventors: TATEDA, Norihiro, KAMEZAWA, Hitoshi
• Application Number:
  US15/026,793
• Publication Number:
  US 20160270708A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2562/04 Arrangements of multiple sensors of the same type
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• 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 5/1075 for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer A61B8/0858 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence

Abstract

Disclosed are a biological information measurement apparatus and a biological information measurement method which are configured to: emit first and second light beams, respectively, to first and second measurement positions which are different positions in a living body; receive corresponding light beams transmitted through or reflected by the living body, to acquire first and second pulse wave signals; and calculate, as biological information, a cardiac output of the living body, based on the first and second pulse wave signals. The biological information measurement apparatus and the biological information measurement method make it possible to continually monitor a change in cardiac output by a simplified apparatus.

Claims

1. A biological information measurement apparatus comprising:

a first pulse wave signal acquisition unit configured to emit a first light beam to a first measurement position of a living body, and receive a corresponding light beam transmitted through or reflected by the living body, to acquire a first pulse wave signal;

a second pulse wave signal acquisition unit configured to emit a second light beam to a second measurement position of the living body different from the first measurement position, and receive a corresponding light beam transmitted through or reflected by the living body, to acquire a second pulse wave signal;

a time lag calculation section configured to calculate a temporal lag amount between a first time point at which the first pulse wave signal has a given phase, and a second time point at which the second pulse wave signal corresponding to the first pulse wave signal has the given phase;

a direct-current component calculation section configured to calculate a direct-current component, based on either one of the first pulse wave signal and the second pulse wave signal;

a pulse rate calculation section configured to calculate a pulse rate of the living body, base on either one of the first pulse wave signal and the second pulse wave signal; and

a biological information calculation section configured to calculate, as biological information, a cardiac output of the living body, based on the lag amount, the direct-current component and the pulse rate.

2. The biological information measurement apparatus as recited in claim 1, wherein the first measurement position and the second measurement position are located on a pathway along which a pulse wave from a heart propagates, at respective different distances from the heart.

3. The biological information measurement apparatus as recited in claim 2, wherein the first measurement position and the second measurement position are two positions of the living body selected from the group consisting of a position of an end of a finger, a position of a base of the finger, a given position of a palm of a hand, a given position of a back of the hand, and a position of a wrist.

4. The biological information measurement apparatus as recited in claim 2, wherein the first measurement position and the second measurement position are two positions of the living body selected from the group consisting of a position of an end of a toe, a position of a base of the toe, a given position of an instep, a given position of a sole, or a position of an ankle.

5. The biological information measurement apparatus as recited in claim 1, which further comprises a cardiac output storage section configured to store therein the cardiac output calculated by the biological information calculation section, wherein

the biological information calculation section is configured to further calculate, as the biological information, an amount of temporal change in the cardiac output, based on the cardiac output stored in the cardiac output storage section.

6. The biological information measurement apparatus as recited in claim 1, wherein the biological information calculation section is configured to further calculate, as the biological information, a pulse wave velocity, based on the lag amount calculated by the time lag calculation section, and a distance between the first measurement position and the second measurement position.

7. The biological information measurement apparatus as recited in claim 1, wherein the biological information calculation section is configured to further calculate, as the biological information, a blood vessel cross-sectional area or a relative blood pressure, based on the direct-current component calculated by the direct-current component calculation section.

8. The biological information measurement apparatus as recited in claim 1, wherein the second pulse wave signal acquisition unit is configured to emit, as the second light beam, a light beam having a wavelength in a green wavelength band, to the living body, and receive a corresponding light beam reflected by the living body, to acquire the second pulse wave signal.

9. The biological information measurement apparatus as recited in claim 1, which further comprises a third pulse wave signal acquisition unit configured to emit a third light beam having a wavelength different from that of the first light beam, to the living body at the first measurement position, and receive a corresponding light beam transmitted through or reflected by the living body, to acquire a third pulse wave signal, wherein

the biological information calculation section is configured to further calculate, as the biological information, an oxygen saturation of the living body, based on the first pulse wave signal and the third pulse wave signal.

10. The biological information measurement apparatus as recited in claim 1, which further comprises an inclination determination section configured to determine an inclination of the apparatus, wherein

the biological information calculation section is configured to correct the cardiac output depending on the inclination determined by the inclination determination section.

11. The biological information measurement apparatus as recited in claim 1, which further comprises an inclination determination section configured to determine an inclination of the apparatus, wherein

the biological information calculation section is configured to calculate the cardiac output only when the inclination determined by the inclination determination section falls within a predetermined range.

12. The biological information measurement apparatus as recited in claim 10, wherein the inclination determination section comprises a tri-axial acceleration sensor, the inclination determination section being configured to determine an inclination of the apparatus, based on tri-axial gravitational acceleration components output from the tri-axial acceleration sensor, and wherein

the biological information calculation section is configured to store the calculated biological information in the biological information storage section, in associated relation with the inclination determined by the inclination determination section.

13. The biological information measurement apparatus as recited in claim 1, which further comprises a biological information storage section configured to store therein the biological information, wherein

the biological information calculation section is configured to store a part or an entirety of the calculated biological information in the biological information storage section.

14. The biological information measurement apparatus as recited in claim 1, which further comprises a display unit, wherein

the biological information calculation section is configured to display a part or an entirety of the calculated biological information on the display unit.

15. A biological information measurement method for use with a biological information measurement apparatus for, based on a first pulse wave signal and a second pulse wave signal obtained, respectively, from a first measurement position and a second measurement position which are different positions in a living body, to measure biological information of the living body, comprising:

a first pulse wave signal acquisition step of emitting a first light beam to the first measurement position, and receiving a corresponding light beam transmitted through or reflected by the living body, to acquire the first pulse wave signal;

a second pulse wave signal acquisition step of emitting a second light beam to the second measurement position, and receiving a corresponding light beam transmitted through or reflected by the living body, to acquire the second pulse wave signal;

a time lag calculation step of calculating a temporal lag amount between a first time point at which the first pulse wave signal has a given phase, and a second time point at which the second pulse wave signal corresponding to the first pulse wave signal has the given phase;

a direct-current component calculation step of calculating a direct-current component, based on either one of the first pulse wave signal and the second pulse wave signal;

a pulse rate calculation step of calculating a pulse rate of the living body, base on either one of the first pulse wave signal and the second pulse wave signal; and

a biological information calculation step of calculating, as biological information, a cardiac output of the living body, based on the lag amount, the direct-current component and the pulse rate.