Blood pressure monitor apparatus

• US 6,428,481 B1
• Filed: 05/30/2000
• Issued: 08/06/2002
• Est. Priority Date: 11/27/1998
• Status: Expired due to Fees

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Kawaguchi, Keizoh, Inukai, Hidekatsu, Nunome, Tomohiro, Yokozeki, Akihiro
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/580,639
• Time in Patent Office: 798 Days
• Field of Search: 600/481, 600/483-485, 600/490, 600/492-495, 600/500-502, 600/526
• US Class Current: 600/485
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• 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 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

A device for monitoring the blood pressure of a living subject, including a pulse-wave-propagation-velocity-relating information obtaining device for successively obtaining pulse-wave-propagation-velocity-relating information which relates to a pulse-wave propagation velocity at which a pulse wave propagates in an artery of the subject, a pulse-period-relating information obtaining device for successively obtaining pulse-period-relating information which relates to a pulse period of the subject, a peripheral-blood-volume-relating information obtaining device for successively obtaining peripheral-blood-volume-relating information which relates to a volume of blood which flows in a peripheral body portion of the subject, and an abnormality judging device for judging that the blood pressure of the subject is abnormal when at least one of the pulse-wave-propagation-velocity-relating information, pulse-period-relating information, and peripheral-blood-volume-relating information does not fall within a corresponding one of a first, a second and a third reference range.

Claims

1. A blood pressure monitor apparatus for monitoring a blood pressure of a living subject, comprising:

pulse-wave-propagation-velocity-relating information obtaining means for successively obtaining pulse-wave-propagation-velocity-relating information which relates to a pulse-wave propagation velocity at which a pulse wave propagates in an artery of the subject;

pulse-period-relating information obtaining means for successively obtaining pulse-period-relating information which relates to a pulse period of the subject;

peripheral-blood-volume-relating information obtaining means for successively obtaining peripheral-blood-volume-relating information which relates to a volume of blood which flows in a peripheral body portion of the subject; and

abnormality judging means for judging that said blood pressure of the subject is abnormal when at least one of said pulse-wave-propagation-velocity-relating information, said pulse-period-relating information, and said peripheral-blood-volume-relating information does not fall within a corresponding one of a first, second and a third reference range, wherein;

said pulse-wave-propagation-velocity-relating information obtaining means comprises first estimated blood pressure determining means for successively determining, as said pulse-wave-propagation-velocity-relating information, a first estimated blood pressure value EBP₁, based on a pulse-wave propagation time, by utilizing a predetermined relationship between first estimated blood pressure value EBP₁, and pulse-wave propagation time DT_RP, said relationship being represented by an equation;

EBP₁=α

₁(1/DT_RP)+β

₁, wherein α

₁, and β

₁ represent coefficients, said pulse-period-relating information obtaining means comprises second estimated blood pressure determining means for successively determining, as said pulse-period-relating information, a second estimated blood pressure value EBP₂, based on a pulse period of the subject, by utilizing a predetermined relationship between second estimated blood pressure value EBP₂ and pulse period RR, said relationship being represented by an equation;

EBP₂=α

₂RR+β

₂, wherein α

₂ and β

₂ represent coefficients, and said peripheral-blood-volume-relating information obtaining means comprises third estimated blood pressure determining means for successively determining, as said peripheral-blood-volume-relating information, a third estimated blood pressure value EBP₃, based on a pulse-wave area, by utilizing a predetermined relationship between third estimated blood pressure value EBP₃ and pulse-wave area VR, said relationship being represented by an equation;

EBP₃=α

₃VR+β

₃, wherein α

₃ and β

₃ represent coefficients.

2. A blood pressure monitor apparatus according to claim 1, wherein said pulse-wave-propagation-velocity-relating information obtaining means comprises an electrocardiographic-waveform detecting device which includes a plurality of electrodes adapted to be attached to a body portion of the subject and detects an electrocardiographic waveform indicative of an action potential of a cardiac muscle of the subject through said electrodes, and a photoelectric-pulse-wave detecting device which includes a plurality of light-emitting elements and a light-receiving element, each of said light-emitting elements emitting, toward a body surface of the subject, a light having a wavelength which is reflected by hemoglobin present in the blood of the subject, said light-receiving element receiving the light scattered by the hemoglobin from the body surface of the subject, said photoelectric-pulse-wave detecting device detecting a photoelectric pulse wave indicative of the volume of the blood flowing in the body surface, said pulse-wave propagation time (DT_RP) representing a time difference between a predetermined point of a pulse of said electrocardiographic waveform detected by said electrocardiographic-waveform detecting device, and a predetermined point of a waveform of a corresponding pulse of said photoelectric pulse wave detected by said photoelectric-pulse-wave detecting device.

3. A blood pressure monitor apparatus according to claim 1, wherein said pulse-period-relating information obtaining means comprises an electrocardiographic-waveform detecting device which includes a plurality of electrodes adapted to be attached to a body portion of the subject and detects an electrocardiographic waveform indicative of an action potential of a cardiac muscle of the subject through said electrodes, said pulse period (RR) representing an interval between successive two R-waves of said electrocardiographic waveform detected by said electrocardiographic-waveform detecting device.

4. A blood pressure monitor apparatus according to claim 1, wherein said peripheral-blood-volume-relating information obtaining means comprises a photoelectric-pulse-wave detecting device which includes a plurality of light-emitting elements and a light-receiving element, each of said light-emitting elements emitting, toward a body surface of the subject, a light having a wavelength which is reflected by hemoglobin present in the blood of the subject, said light-receiving element receiving the light scattered by the hemoglobin from the body surface of the subject, said photoelectric-pulse-wave detecting device detecting a photoelectric pulse wave indicative of the volume of the blood flowing in the body surface, said pulse-wave area (VR) representing an area defined by a waveform of a pulse of said photoelectric pulse wave detected by said photoelectric-pulse-wave detecting device.