Arteriosclerosis evaluating apparatus

• US 6,612,993 B2
• Filed: 02/19/2002
• Issued: 09/02/2003
• Est. Priority Date: 07/02/2001
• Status: Expired due to Fees

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Narimatsu, Kiyoyuki
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/076,502
• Publication Number:
  US 20030004422A1
• Time in Patent Office: 560 Days
• Field of Search: 600/485, 600/490, 600/493-6, 600/500
• US Class Current: 600/500
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• 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 evaluating a degree of arteriosclerosis of a living subject, including a pulse-wave-propagation-velocity-related-information obtaining device which obtains pulse-wave-propagation-velocity-related information that is related to a velocity at which a pulse wave propagates in the subject, a pulse-wave sensor which is adapted to be worn on a body portion of the subject and detects the pulse wave from the body portion, an augmentation-related-information obtaining device for obtaining augmentation-related information that is related to an augmentation of an amplitude of the pulse wave detected by the pulse-wave sensor from an amplitude of an incident-wave component which is contained in the pulse wave, and an arteriosclerosis evaluating device for evaluating the degree of arteriosclerosis of the subject, based on the pulse-wave-propagation-velocity-related information obtained by the pulse-wave-propagation-velocity-related-information obtaining device and the augmentation-related information obtained by the augmentation-related-information obtaining device, according to a prescribed relationship between (A) (a1) pulse-wave-propagation-velocity-related information and (a2) augmentation-related information and (B) degree of arteriosclerosis.

Claims

1. An apparatus for evaluating a degree of arteriosclerosis of a living subject, comprising:

a pulse-wave-propagation-velocity-related-information obtaining device which obtains pulse-wave-propagation-velocity-related information that is related to a velocity at which a pulse wave propagates in the subject;

a pulse-wave sensor which is adapted to be worn on a body portion of the subject and detects the pulse wave from the body portion;

an augmentation-related-information obtaining means for obtaining augmentation-related information that is related to an augmentation of an amplitude of the pulse wave detected by the pulse-wave sensor from an amplitude of an incident-wave component which is contained in the pulse wave; and

an arteriosclerosis evaluating means for evaluating the degree of arteriosclerosis of the subject, based on the pulse-wave-propagation-velocity-related information obtained by the pulse-wave-propagation-velocity-related-information obtaining device and the augmentation-related information obtained by the augmentation-related-information obtaining means, according to a prescribed relationship between (A) (a1) pulse-wave-propagation-velocity-related information and (a2) augmentation-elated information and (B) degree of arteriosclerosis.

2. An apparatus according to claim 1, wherein the pulse-wave-propagation-velocity-related-information obtaining device comprises:

an incident-wave-peak determining means for determining a peak of the incident-wave component contained in the pulse wave detected by the pulse-wave sensor;

a reflected-wave-peak determining means for determining a peak of a reflected-wave component which is contained in the pulse wave detected by the pulse-wave sensor; and

an obtaining means for obtaining the pulse-wave-propagation-velocity-related information based on the peak of the incident-wave component determined by the incident-wave-peak determining means and the peak of the reflected-wave component determined by the reflected-wave-peak determining means.

3. An apparatus according to claim 2, wherein the incident-wave-peak determining means determines the peak of the incident-wave component, by differentiating the pulse wave detected by the pulse-wave sensor.

4. An apparatus according to claim 3 wherein the incident-wave-peak determining means comprises:

means for determining a rising point and a maximal point of a heartbeat-synchronous pulse of the pulse wave detected by the pulse-wave sensor;

means for differentiating a portion of the pulse wave between the rising point and the maximal point; and

means for determining, as the peak of the incident-wave component, an inflection point of the differentiated portion of the pulse wave.

5. An apparatus according to claim 2, wherein the reflected-wave-peak determining means comprises:

means for differentiating the pulse wave detected by the pulse-wave sensor; and

means for determining, as the peak of the reflected-wave component, a maximal point of the pulse wave.

6. An apparatus according to claim 1, wherein the pulse-wave sensor comprises a pressure-pulse-wave sensor which is adapted to be pressed against an artery of the subject and detects, as the pulse wave, a pressure pulse wave produced from the artery.

7. An apparatus according to claim 6, wherein the pressure-pulse-wave sensor detects the pressure pulse wave produced from the artery selected from the group consisting of a carotid artery, a brachial artery, a radial artery, and a femoral artery.

8. An apparatus according to claim 6, wherein the pressure-pulse-wave sensor comprises a plurality of pressure-sensing elements each of which can detect the pressure pulse wave produced from the artery, and a press surface in which the pressure-sensing elements are arranged in at least one array such that in a state in which the pressure-pulse-wave sensor is worn on the body portion and the press surface is pressed against a surface of the body portion, the array of the pressure-sensing elements crosses over the artery and at least one of the pressure-sensing elements is positioned right above the artery.

9. An apparatus for evaluation of a degree of arteriosclerosis of a living subject, comprising:

a pulse-wave-propagation-velocity-related-information obtaining device which obtains pulse-wave-propagation-velocity-related information that is related to a velocity at which a pulse wave propagates in the subject;

a pulse-wave sensor which is adapted to be worn on a body portion of the subject and detects the pulse wave from the body portion;

an augmentation-related-information obtaining means for obtaining augmentation-related information that is related to an augmentation of an amplitude of the pulse wave detected by the pulse-wave sensor from an amplitude of an incident-wave component which is contained in the pulse wave; and

a simultaneously displaying device which simultaneously displays the pulse-wave-propagation-velocity-related information obtained by the pulse-wave-propagation-velocity-related-information obtaining device and the augmentation-related information obtained by the augmentation-related-information obtaining means.

10. An apparatus according to claim 9, wherein the augmentation-related-information obtaining device comprises augmentation-index determining means for determining, as the augmentation-related information, an augmentation index indicative of the augmentation of the amplitude of the pulse wave from the amplitude of the incident-wave component, and

wherein the simultaneously displaying device comprises a display device which displays, in a two-dimensional coordinate system defined by a first axis representative of pulse-wave-propagation-velocity-related information and a second axis representative of augmentation index, a symbol at a position having a pair of coordinates corresponding to the pulse-wave-propagation-velocity-related information obtained by the pulse-wave-propagation-velocity-related-information obtaining device and the augmentation index determined by the augmentation-index determining means.

11. An apparatus according to claim 10, wherein the display device displays the two-dimensional coordinate system which includes (A) an arteriosclerosis area corresponding to an arteriosclerosis range of each of the pulse-wave-propagation-velocity-related information and the augmentation index represented by the first and second axes, and (B) al least one of (b1) an arteriosclerosis-suspect area corresponding to a normal range of the pulse-wave-propagation-velocity-related information and the arteriosclerosis range of the augmentation index and (b2) a hypertension area corresponding to the arteriosclerosis range of the pulse-wave-propagation-velocity-related information and a normal range of the augmentation index.

12. An apparatus according to claim 9, wherein the pulse-wave-propagation-velocity-related-information obtaining device comprises:

an incident-wave-peak determining means for determining a peak of the incident-wave component contained in the pulse wave detected by the pulse-wave-sensor;

a reflected-wave-peak determining means for determining a peak of a reflected-wave component which is contained in the pulse wave detected by the pulse-wave sensor; and

an obtaining means for obtaining the pulse-wave-propagation-velocity-related information based on the peak of the incident-wave component determined by the incident-wave-peak determining means and the peak of the reflected-wave component determined by the reflected-wave-peak determining means.

13. An apparatus according to claim 9, further comprising an arteriosclerosis evaluating means for evaluating the degree of arteriosclerosis of the subject, based on the pulse-wave-propagation-velocity-related information obtained by the pulse-wave-propagation-velocity-related-information obtaining device and the augmentation-related information obtained by the augmentation-related-information obtaining means, according to a prescribed relationship between (A) (a1) pulse-wave-propagation-velocity-related information and (a2) augmentation-elated information and (B) degree of arteriosclerosis.