Arteriosclerosis diagnosing apparatus

• US 6,733,460 B2
• Filed: 07/15/2002
• Issued: 05/11/2004
• Est. Priority Date: 12/12/2001
• Status: Expired due to Term

• Current Assignee: Fukuda Denshi Company Limited
• Original Assignee: Colin Medical Technology Corporation (Omron Corporation)
• Inventors: Ogura, Toshihiko
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US10/193,899
• Publication Number:
  US 20030109788A1
• Time in Patent Office: 666 Days
• Field of Search: 600/490, 600/481, 600/485, 600/491, 600/493, 600/494, 600/495, 600/496, 600/500, 600/501, 600/502
• US Class Current: 600/490
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• 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

Abstract

An apparatus for diagnosing arteriosclerosis of a living subject, including an inflatable cuff which is adapted to be wound around a first portion of the subject to press the first portion with a pressing pressure, a pulse-wave detecting device which detects a pulse wave that is produced from an artery of the first portion of the subject pressed by the cuff with the pressing pressure and is transmitted to the cuff, and an arteriosclerosis judging device for judging, based on a change of the pulse wave caused by a change of the pressing pressure of the cuff, whether there is an arteriosclerotic lesion in a second portion of the subject that is located upstream of the first portion in a direction in which blood flows in the artery.

Claims

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

an inflatable cuff which is adapted to be wound around a first portion of the subject to press said first portion with a pressing pressure;

a pulse-wave detecting device which detects a pulse wave that is produced from an artery of said first portion of the subject pressed by the cuff with the pressing pressure and is transmitted to the cuff; and

an arteriosclerosis judging means for judging, based on a change of the pulse wave caused by a change of the pressing pressure of the cuff, whether there is an arteriosclerotic lesion in a second portion of the subject that is located upstream of said first portion in a direction in which blood flows in the artery.

2. An apparatus according to claim 1, wherein the arteriosclerosis judging means comprises:

means for holding the pressing pressure of the cuff at a first target pressure around a diastolic blood pressure of said first portion of the subject;

means for reading in a first heartbeat-synchronous pulse of the pulse wave detected by the pulse-wave detecting device from the artery of said first portion pressed by the cuff whose pressing pressure is held at the first target pressure;

means for holding the pressing pressure of the cuff at a second target pressure around a mean blood pressure of said first portion of the subject;

means for reading in a second heartbeat-synchronous pulse of the pulse wave detected by the pulse-wave detecting device from the artery of said first portion pressed by the cuff whose pressing pressure is held at the second target pressure; and

means for determining, as said change of the pulse wave, a change of a shape of the second heartbeat-synchronous pulse from a shape of the first heartbeat-synchronous pulse with respect to a change of the second target pressure from the first target pressure.

3. An apparatus according to claim 2, wherein the arteriosclerosis judging means further comprises means for judging whether a change value representing the change of the shape of the second heartbeat-synchronous pulse from the shape of the first heartbeat-synchronous pulse is smaller than a reference value and judging, when a positive judgment is made, that there is an arteriosclerotic lesion in said second portion of the subject.

4. An apparatus for diagnosing arteriosclerosis of an inferior limb of a living subject, comprising:

a left-superior-limb cuff which is adapted to be wound around a left superior limb of the subject to press the left superior limb with a first pressing pressure;

a right-superior-limb cuff which is adapted to be wound around a right superior limb of the subject to press the right superior limb with a second pressing pressure;

an inferior-limb cuff which is adapted to be wound around the inferior limb of the subject;

a left-superior-limb pulse-wave detecting device which detects, as a left-superior-limb pulse wave, a pulse wave which is produced from an artery of the left superior limb pressed by the left-superior-limb cuff with the first pressing pressure and is transmitted to the left-superior-limb cuff;

a right-superior-limb pulse-wave detecting device which detects, as a right-superior-limb pulse wave, the pulse wave which is produced from an artery of the right superior limb pressed by the right-superior-limb cuff with the second pressing pressure and is transmitted to the right-superior-limb cuff;

an inferior-limb pulse-wave detecting device which detects, as an inferior-limb pulse wave, the pulse wave which is produced from an artery of the inferior limb pressed by the inferior-limb cuff and is transmitted to the inferior-limb cuff;

a change-value calculating means for calculating a first change value representing a change of the left-superior-limb pulse wave caused by a change of the first pressing pressure of the left-superior-limb cuff, and a second change value representing a change of the right-superior-limb pulse wave caused by a change of the second pressing pressure of the right-superior-limb cuff;

an arteriosclerosis judging means for judging, based on a comparison of the first and second change values calculated by the change-value calculating means, which is lower, a degree of arteriosclerosis of a first portion of the subject located between the heart of the subject and the left superior limb or a degree of arteriosclerosis of a second portion of the subject located between the heart and the right superior limb; and

a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on (a) one of the left-superior-limb pulse wave and the right-superior-limb pulse wave that corresponds to one of the first and second portions that has the degree of arteriosclerosis judged as being lower than the degree of arteriosclerosis of the other of the first and second portions by the arteriosclerosis judging means, and (b) the inferior-limb pulse wave detected by the inferior-limb pulse-wave detecting device, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.

5. An apparatus according to claim 4, wherein the change-value calculating means comprises:

means for holding the first and second pressing pressures of the left and right superior-limb cuffs at a first target pressure around respective diastolic blood pressures of the left and right superior limbs of the subject;

means for reading in respective first heartbeat-synchronous pulses of the left and right superior-limb pulse waves detected by the left and right superior-limb pulse-wave detecting devices from the respective arteries of the left and right superior limbs pressed by the left and right superior-limb cuffs whose first and second pressing pressures are held at the first target pressure;

means for holding the first and second pressing pressures of the left and right superior-limb cuffs at a second target pressure around respective mean blood pressures of the left and right superior limbs of the subject;

means for reading in respective second heartbeat-synchronous pulses of the left and right superior-limb pulse waves detected by the left and right superior-limb pulse-wave detecting devices from the respective arteries of the left and right superior limbs pressed by the left and right superior-limb cuffs whose first and second pressing pressures are held at the second target pressure; and

means for determining, as the respective changes of the left and right superior-limb pulse waves, respective changes of respective shapes of the respective second heartbeat-synchronous pulses from respective shapes of the respective first heartbeat-synchronous pulses, each with respect to a change of the second target pressure from the first target pressure.

8. An apparatus according to claim 5, wherein the arteriosclerosis judging means comprises means for judging which one of the first and second change values is greater than the other of the first and second change values, and judging that one of the first and second portions of the subject that corresponds to one of the first and second change values that is greater than the other of the first and second change values has a lower degree of arteriosclerosis than a degree of arteriosclerosis of the other of the first and second portions.

6. An apparatus for diagnosing arteriosclerosis of a living subject, comprising:

a first-pulse-wave detecting device including a first detecting portion which is adapted to be worn on a first body portion of the subject to detect, as a first pulse wave, a pulse wave produced from the first body portion;

a second-pulse-wave detecting device including a second detecting portion which is adapted to be worn on a second body portion of the subject to detect, as a second pulse wave, the pulse wave produced from the second body portion;

a synchronism judging means for judging whether the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device are synchronous with each other; and

a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on the first and second pulse waves judged as being synchronous with each other by the synchronism judging means, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.

9. An apparatus according to claim 6, wherein the synchronism judging means comprises:

means for determining respective first characteristic points of respective heartbeat-synchronous pulses of the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device, and respective second characteristic points of the respective heartbeat-synchronous pulses of the first and second pulse waves;

means for determining a first time difference between respective times of occurrence of the respective first characteristic points, and a second time difference between respective times of occurrence of the respective second characteristic points; and

means for judging whether the first and second time differences are substantially equal to each other and, when a positive judgment is made, judging that the first and second pulse waves are synchronous with each other.

7. An apparatus for diagnosing arteriosclerosis of a living subject, comprising:

a first-pulse-wave detecting device including a first detecting portion which is adapted to be worn on a first body portion of the subject to detect, as a first pulse wave, a pulse wave produced from the first body portion;

a second-pulse-wave detecting device including a second detecting portion which is adapted to be worn on a second body portion of the subject to detect, as a second pulse wave, the pulse wave produced from the second body portion;

a normal-pulse-period-range determining means for determining a normal pulse-period range based on one of the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device;

an arrhythmia judging means for judging, when one of a pulse period of the first pulse wave and a pulse period of the second pulse wave falls in the normal pulse-period range determined by the normal-pulse-period-range determining means, that the first and second pulse waves are not arrhythmic; and

a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on the first and second pulse waves judged as being not arrhythmic by the arrhythmia judging means, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.

10. An apparatus according to claim 7, wherein the normal-pulse-period-range determining means comprises:

means for determining respective pulse periods of a plurality of heartbeat-synchronous pulses of said one of the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device;

means for determining an average of the determined pulse periods; and

means for determining the normal pulse-period range whose middle value is equal to the determined average and whose upper and lower limit values are determined based on the determined average.