Pulse-wave-propagation-velocity measuring apparatus

• US 20030153839A1
• Filed: 10/07/2002
• Published: 08/14/2003
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Nomura, Takashi
• Granted Patent: US 6,758,819 B2
• Time in Patent Office: Days
• US Class Current: 600/492
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/107 Measuring physical dimensions, e.g. size of the entire body or parts thereof
• CPC Class Codes: A61B 5/6824 Arm or wrist

Abstract

An apparatus for measuring a velocity at which a pulse wave propagates between a first portion and a second portion of a living subject, the apparatus including a propagation-signal producing device which is adapted to be worn on the first portion of the subject and produces a propagation signal, a propagation-signal detecting device which is adapted to be worn on the second portion of the subject and detects the propagation signal that has been produced by the propagation-signal producing device, has propagated through a body tissue of the subject, and has reached the second portion, a blood-vessel-length determining device for determining a length of a blood vessel of the subject that is located between the first and second portions of the subject, based on a signal propagation time from a time when the propagation signal is produced by the propagation-signal producing device, to a time when the propagation signal is detected by the propagation-signal detecting device, and a pre-stored velocity at which the propagation signal propagates through a body tissue of a human person, and a pulse-wave-propagation-velocity determining device for determining the velocity at which the pulse wave propagates between the first and second portions of the subject, based on the length of the blood vessel determined by the blood-vessel-length determining device.

Claims

1. An apparatus for measuring a velocity at which a pulse wave propagates between a first portion and a second portion of a living subject, the apparatus comprising:

a propagation-signal producing device which is adapted to be worn on the first portion of the subject and produces a propagation signal;

a propagation-signal detecting device which is adapted to be worn on the second portion of the subject and detects the propagation signal that has been produced by the propagation-signal producing device, has propagated through a body tissue of the subject, and has reached the second portion;

a blood-vessel-length determining means for determining a length of a blood vessel of the subject that is located between the first and second portions of the subject, based on a signal propagation time from a time when the propagation signal is produced by the propagation-signal producing device, to a time when the propagation signal is detected by the propagation-signal detecting device, and a pre-stored velocity at which the propagation signal propagates through a body tissue of a human person; and

a pulse-wave-prop agation-velocity determining means for determining the velocity at which the pulse wave propagates between the first and second portions of the subject, based on the length of the blood vessel determined by the blood-vessel-length determining means.

4. An apparatus according to claim 1, further comprising a memory device which stores the velocity at which the propagation signal propagates through the body tissue of the human person.

5. An apparatus according to claim 1, further comprising:

a first heartbeat-synchronous-signal detecting device which is adapted to be worn on the first portion of the subject and detects a first heartbeat-synchronous signal from the first portion; and

a second heartbeat-synchronous-signal detecting device which is adapted to be worn on the second portion of the subject and detects a second heartbeat-synchronous signal from the second portion,

wherein the pulse-wave-propagation-velocity determining means determines the velocity at which the pulse wave propagates between the first and second portions of the subject, by dividing the length of the blood vessel determined by the blood-vessel-length determining means, by a pulse-wave propagation time from a time when the first heartbeat-synchronous signal is detected by the first heartbeat-synchronous-signal detecting device, to a time when the second heartbeat-synchronous signal is detected by the second heartbeat-synchronous-signal detecting device.

6. An apparatus according to claim 5, wherein the propagation-signal producing device is supported by the first heartbeat-synchronous-signal detecting device, and the propagation-signal detecting device is supported by the second heartbeat-synchronous-signal detecting device.

7. An apparatus according to claim 1, further comprising a display device which displays the velocity determined by the pulse-wave-propagation-velocity determining means.

2. An apparatus for measuring a velocity at which a pulse wave propagates between a first portion and a second portion of a living subject, the apparatus comprising:

a bed on which the subject lies;

a contour determining device which determines a contour of the subject lying on the bed;

a blood-vessel-length determining means for determining a length of a blood vessel of the subject that is located between the first and second portions of the subject, based on the contour of the subject determined by the contour determining device and respective positions of the first and second portions of the subject in the contour; and

a pulse-wave-prop agation-velocity determining means for determining the velocity at which the pulse wave propagates between the first and second portions of the subject, based on the length of the blood vessel determined by the blood-vessel-length determining means.

8. An apparatus according to claim 2, wherein the contour determining device comprises:

an image taking device which takes an image of the subject lying on the bed; and

determining means for determining, based on the image taken by the image taking device, the contour of the subject.

9. An apparatus according to claim 2, further comprising a position designating device operable for designating the respective positions of the first and second portions of the subject, in the contour determined by the contour determining device.

3. An apparatus for measuring a velocity at which a pulse wave propagates between a first portion and a second portion of a living subject, the apparatus comprising:

a blood-vessel-image taking device which takes an image of a blood vessel of the subject;

a blood-vessel-length determining means for determining a length of a portion of the blood vessel of the subject that is located between the first and second portions of the subject, based on the image of the blood vessel of the subject taken by the blood-vessel-image taking device; and

a pulse-wave-propagation-velocity determining means for determining the velocity at which the pulse wave propagates between the first and second portions of the subject, based on the length of the portion of the blood vessel determined by the blood-vessel-length determining means.

10. An apparatus according to claim 3, wherein the blood-vessel-image taking device comprises:

an X-ray computerized-tomography scan device which takes two images of an entire body of the subject at two different energy levels, respectively; and

blood-vessel-image determining means for determining the image of the blood vessel based on the two images taken by the X-ray computerized-tomography scan device.

11. An apparatus according to claim 3, further comprising a position designating device operable for designating respective positions of the first and second portions of the subject, in the image of the blood vessel taken by the blood-vessel-image taking device, wherein the blood-vessel-length determining means determines the length of the portion of the blood vessel of the subject, based on the image of the blood vessel of the subject taken by the blood-vessel-image taking device and the designated positions of the first and second portions of the subject.