Apparatus for measuring pulse-wave propagation velocity

• US 6,547,742 B2
• Filed: 01/15/2002
• Issued: 04/15/2003
• Est. Priority Date: 11/06/1995
• Status: Expired due to Fees

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Sakai, Hiroshi, Oka, Tohru, Ikawa, Tomoko, Nomura, Takashi, Ogura, Toshihiko, Inukai, Hidekatsu
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/044,993
• Publication Number:
  US 20020087087A1
• Time in Patent Office: 455 Days
• Field of Search: 600/485, 600/490, 600/493-6, 600/500
• US Class Current: 600/494
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus including an electrocardiographic-waveform detecting device which detects an electrocardiographic waveform from the subject, a pulse-wave sensor which is adapted to be worn on the subject and which detects the pulse wave from the subject, a time-difference determining device for determining a time difference between a first periodic point relating to the detected electrocardiographic waveform and a second periodic point relating to the detected pulse wave, and a propagation-velocity determining means for determining the propagation velocity of the pulse wave based on the determined time difference.

Claims

1. An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus comprising:

a first and a second heartbeat-synchronous-wave sensor which detect, as the pulse wave, a first and a second heartbeat-synchronous wave, respectively, each of which is produced from the artery of the subject in synchronism with a heartbeat of the subject;

maximum-slope-line determining means for determining, with respect to at least one of said first and second waves, a maximum-slope line which passes through a maximum-slope point where a heartbeat-synchronous pulse of said one wave takes a maximum slope, such that said maximum-slope line has the maximum slope;

base-line determining means for determining, with respect to said one wave, a base line which passes through respective minimum points on.both sides of a maximum point of said heartbeat-synchronous pulse of said one wave;

reference-point determining means for determining, as a reference point, a point of intersection of said maximum-slope line and said base line; and

propagation-velocity determining means for determining the propagation velocity of the pulse wave based on a time difference between said reference point determined with respect to said heartbeat-synchronous pulse of said one wave and a corresponding heartbeat-synchronous pulse of the other of said first and second waves.

2. An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus comprising:

a first and a second heartbeat-synchronous-wave sensor which detect, as the pulse wave, a first and a second heartbeat-synchronous wave, respectively, each of which is produced from the artery of the subject in synchronism with a heartbeat of the subject;

maximum-slope-line determining means for determining, with respect to at least one of said first and second waves, a maximum-slope line which passes through a maximum-slope point where a heartbeat-synchronous pulse of said one wave takes a maximum slope, such that said maximum-slope line has the maximum slope;

maximum-point-line determining means for determining, with respect to said one wave, a maximum-point line which passes through a maximum point where said heartbeat-synchronous pulse of said one wave takes a maximum amplitude, such that said maximum-point line is parallel to a base line which passes through respective minimum points on both sides of the maximum point of said heartbeat-synchronous pulse of said one wave;

reference-point determining means for determining a reference point from a point of intersection of said one wave and a line which passes through a point of intersection of said maximum-slope line and said maximum-point line and is perpendicular to the maximum-point line; and

propagation-velocity determining means for determining the propagation velocity of the pulse wave based on a time difference between said reference point determined with respect to said heartbeat-synchronous pulse of said one wave and a corresponding heartbeat-synchronous pulse of the other of said first and second waves.

3. An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, the apparatus comprising:

a first and a second heartbeat-synchronous-wave sensor which detect, as the pulse wave, a first and a second heartbeat-synchronous wave, respectively, each of which is produced from the artery of the subject in synchronism with a heartbeat of the subject;

reference-point determining means for determining, with respect to at least one of said first and second waves, a maximum-slope point where a heartbeat-synchronous pulse of said one wave takes a maximum slope, and determining the determined maximum-slope point as a reference point; and

propagation-velocity determining means for determining the propagation velocity of the pulse wave based on a time difference between said reference point determined with respect to said heartbeat-synchronous pulse of said one wave and a corresponding heartbeat-synchronous pulse of the other of said first and second waves.