Pulse-wave propagation information obtaining apparatus

• US 6,315,734 B1
• Filed: 01/31/2000
• Issued: 11/13/2001
• Est. Priority Date: 11/01/1999
• Status: Expired due to Term

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Nunome, Tomohiro
• Primary Examiner(s): Lacyk, John P.
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US09/494,038
• Time in Patent Office: 652 Days
• Field of Search: 600/500, 600/501, 600/502, 600/503, 600/481, 600/483, 600/484, 600/485, 600/486, 600/490, 600/492, 600/493, 600/494, 600/495, 600/496
• US Class Current: 600/500
• CPC Class Codes: A61B 5/02233 Occluders specially adapted therefor tourniquets A61B17/132
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves

Abstract

An apparatus for obtaining an information relating to a propagation velocity of a pulse wave which propagates through an artery of a living subject, including: a first signal detecting device which is adapted to be worn on a first portion of the subject and which detects a first signal generated from the first portion in synchronism with a heart beat of the subject; a pulse-wave detecting device which is adapted to be worn on a second portion of the subject and which detects, as a second signal, a notch of the pulse wave generated from the second portion in synchronism with the heart beat of the subject; a pressing device which is adapted to be worn on a third portion of the subject to press the third portion, the third portion being on a downstream side relative to the second portion with respect to the artery and being in proximity to the second portion; and pulse-wave propagation time determining means for determining, as the information, a time difference between a time when the first signal is detected by the first signal detecting device and a time when the notch of the pulse wave is detected by the pulse-wave detecting device in a state in which the third portion is pressed by the pressing device.

Claims

1. An apparatus for obtaining an information relating to a propagation velocity of a pulse wave which propagates through an artery of a living subject, comprising:

a first signal detecting device which is adapted to be worn on a first portion of the subject and which detects a first signal generated from the first portion in synchronism with a heart beat of the subject;

a pulse-wave detecting device which is adapted to be worn on a second portion of the subject and which detects, as a second signal, a notch of said pulse wave generated from the second portion in synchronism with said heart beat of the subject;

a pressing device which is adapted to be worn on a third portion of the subject to press the third portion, the third portion being on a downstream side relative to the second portion of the subject with respect to said artery and being in proximity to the second portion; and

pulse-wave propagation time determining means for determining, as said information, a time difference between a time when said first signal is detected by the first signal detecting device and a time when said notch of the pulse wave is detected by the pulse-wave detecting device in a state in which the third portion of the subject is pressed by the pressing device.

2. An apparatus according to claim 1, wherein said pulse-wave detecting device comprises a brachial pulse-wave detecting device which is adapted to be worn on an upper arm of the subject and which detects a notch of a brachial pulse wave of the subject, and said pressing device comprises a first rubber bag which is adapted to be worn on the upper arm of the subject for determining a blood pressure of the subject, the apparatus further comprising:

a pressure control device which changes a pressing pressure of the first rubber bag; and

a blood pressure determining device which determines said blood pressure of the subject, based on signals successively detected while the pressing pressure of the first rubber bag is changed by the pressure control device.

3. An apparatus according to claim 2, wherein said brachial pulse-wave detecting device comprises a second rubber bag for detecting said brachial pulse wave of the subject, the second rubber bag being adapted to be worn on an upstream side relative to a portion of the upper arm on which the first rubber bag is worn, the apparatus further comprising an outer bag in which the first and second rubber bags are accommodated in a state in which the first and second rubber bags are spaced from each other.

4. An apparatus according to claim 2, wherein said pulse-wave propagation time determining means determines said time difference between said time when said first signal is detected and said time when said notch of the brachial pulse wave is detected by the brachial pulse-wave detecting device in said state in which the upper arm is pressed by said first rubber bag with a pressing pressure greater than a reference value which is greater than a systolic blood pressure of the subject, and wherein said blood pressure determining device determines, after detection of the first signal and the notch of the brachial pulse wave, said blood pressure of the subject, based on the signals successively detected while the pressing pressure of the first rubber bag is decreased by the pressure control device.

5. An apparatus according to claim 1, wherein said pulse-wave propagation time determining means determines said time difference between said time when said first signal is detected and said time when said notch of the pulse wave is detected in said state in which said third portion is pressed by said pressing device with a pressing pressure greater than a systolic blood pressure of the subject.

6. An apparatus according to claim 1, wherein said first signal detecting device comprises a phonocardiographic transducer which detects, as the first signal, one of a first and a second heart sound of the subject.

7. An apparatus according to claim 6, wherein said phonocardiographic transducer has a switch which is manually operable for starting the apparatus.

8. An apparatus according to claim 1, further comprising a pulse-wave propagation velocity determining means for determining said propagation velocity of the pulse wave, by dividing a distance between a heart of the subject and the second portion of the subject by the time difference determined by said pulse-wave propagation time determining means.

9. An apparatus according to claim 8, further comprising an input device which is operable for inputting a stature of the subject, wherein said pulse-wave propagation velocity determining means comprises means for determining said distance between the heart of the subject and the second portion of the subject, based on said stature of the subject input through the input device, according to a predetermined relationship between distance and stature;

and means for determining said propagation velocity of the pulse wave by dividing the determined distance by the time difference determined by said pulse-wave propagation time determining means.