Pulse-wave-propagation-relating information obtaining apparatus and arterial-bifurcate-portion determining apparatus

• US 6,475,155 B2
• Filed: 12/01/2000
• Issued: 11/05/2002
• Est. Priority Date: 12/08/1999
• Status: Expired due to Fees

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Honda, Takashi, Harada, Chikao, Ogura, Toshihiko, Narimatsu, Kiyoyuki
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/726,452
• Publication Number:
  US 20010003792A1
• Time in Patent Office: 704 Days
• Field of Search: 600/485, 600/500.3, 600/587
• US Class Current: 600/500
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/6822 Neck

Abstract

An apparatus for obtaining a pulse-wave-propagation-relating information of a living subject, including a bifurcate-portion determining device which determines a bifurcate portion of an artery of the subject that is present under a skin of the subject, a pulse-wave-detect-portion determining device for determining, based on the determined bifurcate portion of the artery, a pulse-wave-detect portion of the artery from which a pulse wave is detected, a reference-point determining device for determining a reference point on the pulse wave detected from the determined pulse-wave-detect portion of the artery, and a pulse-wave-propagation-relating-information obtaining device for obtaining the pulse-wave-propagation-relating information of the subject based on the determined reference point of the pulse wave.

Claims

1. An apparatus for obtaining a pulse-wave-propagation-relating information of a living subject, comprising:

a bifurcate-portion determining device which determines a bifurcate portion of an artery of the subject that is present under a skin of the subject;

a pulse-wave-detect-portion determining means for determining, based on the determined bifurcate portion of the artery, a pulse-wave-detect portion of the artery from which a pulse wave is detected;

a reference-point determining means for determining a reference point on the pulse wave detected from the determined pulse-wave-detect portion of the artery; and

a pulse-wave-propagation-relating-information obtaining means for obtaining the pulse-wave-propagation-relating information of the subject based on the determined reference point of the pulse wave.

2. An apparatus according to claim 1, wherein the bifurcate-portion determining device comprises:

a pressure-pulse-wave sensor including a plurality of pressure-sensing elements which are arranged at a first regular interval of distance in an arrangement direction over a distance longer than a diameter of the artery, and each of which produces a pulse-wave signal representing a pressure pulse wave propagated thereto from the artery;

a distribution-curve obtaining means for obtaining a plurality of distribution curves each of which represents a relationship between respective positions of the pressure-sensing elements in the arrangement direction and respective amplitudes or respective minimum magnitudes of the respective pressure pulse waves represented by the respective pulse-wave signals produced by the pressure-sensing elements which are located at a corresponding one of a plurality of curve-obtain positions which are arranged at a second regular interval of distance in a predetermined range in a lengthwise direction of the artery and at each of which the pressure-sensing elements arranged in the arrangement direction traverse the artery; and

a bifurcate-portion determining means for determining, based on the distribution curves respectively corresponding to the curve-obtain positions, the bifurcate portion of the artery in the predetermined range in the lengthwise direction of the artery.

3. An apparatus according to claim 2 wherein the pulse-wave-detect-portion determining means determines, as the pulse-wave-detect portion of the artery, a portion of the artery that is distant, by a predetermined distance, downstream of the determined bifurcate portion of the artery in a direction in which blood flows in the artery.

4. An apparatus according to claim 2 wherein the pulse-wave-propagation-relating-information obtaining means obtains the pulse-wave-progagation-relating information of the subject based on a time difference between a reference point on a waveform of an electrocardiogram or a phonocardiogram and the determined reference point of a pressure pulse wave as the pulse wave detected from the determined pulse-wave-detect portion of a carotid artery as the artery.

5. An apparatus according claim 2 wherein the bifurcate-portion determining means determines the bifurcate portion of the artery based on at least one second interval between the two curve-obtain positions one of which corresponds to the distribution curve having a single peak and the other of which corresponds to the distribution curve having two peaks.

6. An apparatus according to claim 5 wherein the pulse-wave-detect-portion determining means determines, as the pulse-wave-detect portion of the artery, a portion of the artery that is distant, by a predetermined distance, downstream of the determined bifurcate portion of the artery in a direction in which blood flows in the artery.

7. An apparatus according to claim 5 wherein the pulse-wave-propagation-relating-information obtaining means obtains the pulse-wave-propagation-relating information of the subject based on a time difference between a reference point on a waveform of an electrocardiogram or a phonocardiogram and the determined reference point of a pressure pulse wave as the pulse wave detected from the determined pulse-wave-detect portion of a carotid artery as the artery.

8. An apparatus according to claim 1, wherein the pulse-wave-detect-portion determining means determines, as the pulse-wave-detect portion of the artery, a portion of the artery that is distant, by a predetermined distance, downstream of the determined bifurcate portion of the artery in a direction in which blood flows in the artery.

9. An apparatus according to claim 8 wherein the pulse-wave-propagation-relating-information obtaining means obtains the pulse-wave-propagation-relating information of the subject based on a time difference between a reference point on a waveform of an electrocardiogram or a phonocardiogram and the determined reference point of a pressure pulse wave as the pulse wave detected from the determined pulse-wave-detect portion of a carotid artery as the artery.

10. An apparatus according to claim 1, wherein the pulse-wave-propagation-relating-information obtaining means obtains the pulse-wave-propagation-relating information of the subject based on a time difference between a reference point on a waveform of an electrocardiogram or a phonocardiogram and the determined reference point of a pressure pulse wave as the pulse wave detected from the determined pulse-wave-detect portion of a carotid artery as the artery.

11. An apparatus according to claim 2, wherein the pressure-pulse-wave sensor includes the pressure-sensing elements which are arranged in a matrix such that the elements are arranged at a regular interval of distance along a plurality of first straight lines parallel to each other and at a regular interval of distance along a pulrality of second straight lines which are parallel to each other and are perpendicular to the first straight lines.

12. An apparatus for determining a bifurcate portion of an artery of a living subject that is present under a skin of the subject comprising:

a pressure-pulse-wave sensor including a plurality of pressure-sensing elements which are arranged at a first regular interval of distance in an arrangement direction over a distance longer than a diameter of the artery, and each of which produces a pulse-wave signal representing a pressure pulse wave propagated thereto from the artery;

a distribution-curve obtaining means for obtaining a plurality of distribution curves each of which represents a relationship between respective positions of the pressure-sensing elements in the arrangement direction and respective amplitudes or respective minimum magnitudes of the respective pressure pulse waves represented by the respective pulse-wave signals produced by the pressure-sensing elements which are located at a corresponding one of a plurality of curve-obtain positions which are arranged at a second regular interval of distance in a predetermined range in a lengthwise direction of the artery and at each of which the pressure-sensing elements arranged in the arrangement direction traverse the artery; and

a bifurcate-portion determining means for determing, based on the distribution curves respectively corresponding to the curve-obtain positions, the bifurcate portion of the artery in the predetermined range in the lengthwise direction of the artery.

13. An apparatus according to claim 12, wherein the bifurcate-portion determining means determines the bifurcate portion of the artery based on at least one second interval between the two curve-obtain positions one of which corresponds to the distribution curve having a single peak and the other of which corresponds to the distribution curve having two peaks.