Blood-pressure-waveform monitoring apparatus

• US 6,645,154 B2
• Filed: 12/28/2001
• Issued: 11/11/2003
• Est. Priority Date: 04/27/2001
• Status: Expired due to Fees

• Current Assignee: Colin Medical Technology Corporation (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Oka, Tohru
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/028,709
• Publication Number:
  US 20020161305A1
• Time in Patent Office: 683 Days
• Field of Search: 600/485, 600/490, 600/493-6, 600/500
• 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 5/02225 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 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure

Abstract

An apparatus for monitoring a blood-pressure waveform representing a blood pressure of a living subject, including a cuff which is around a portion of the subject, a blood-pressure determining device which determines a blood pressure of the subject based on a signal obtained while a pressure in the cuff is changed, a blood-pressure-waveform detecting device which continuously detects the blood-pressure waveform, a display device which displays the blood-pressure waveform, a cuff-using-blood-pressure-measurement starting device for operating, when a prescribed blood-pressure-measurement-starting condition is satisfied, the blood-pressure determining device to determine the blood pressure of the subject, a pulse-wave detecting device which is adapted to be worn on a portion of the subject that is not located on a downstream side of the portion around which the cuff is wound, an estimated-blood-pressure-waveform determining device for continuously determining, based on the pulse wave detected by the pulse-wave detecting device, a estimated blood-pressure waveform representing an estimated blood pressure of the subject, according to a predetermined relationship between blood-pressure waveform and pulse wave, and a waveform-displaying control device for operating, when the blood-pressure waveform is not abnormal, the display device to display the blood-pressure waveform, and operating, when the blood-pressure waveform is abnormal, the display device to display the estimated blood-pressure waveform.

Claims

1. An apparatus for monitoring a blood-pressure waveform representing a blood pressure of a living subject, comprising:

an inflatable cuff which is adapted to be wound around a first portion of the subject;

a blood-pressure determining device which determines a blood pressure of the subject based on a signal obtained while a pressure in the cuff is changed;

a blood-pressure-waveform detecting device which is adapted to be worn on a second portion of the subject and continuously detects the blood-pressure waveform representing the blood pressure of the subject;

a display device which displays the blood-pressure waveform detected by the blood-pressure-waveform detecting device;

a cuff-using-blood-pressure-measurement starting means for operating, when a prescribed blood-pressure-measurement-starting condition is satisfied, the blood-pressure determining device to determine the blood pressure of the subject;

a pulse-wave detecting device which is adapted to be worn on a third portion of the subject that is not located on a downstream side of the first portion around which the cuff is wound, and which detects a pulse wave from the third portion of the subject;

an estimated-blood-pressure-waveform determining means for continuously determining, based on the pulse wave detected by the pulse-wave detecting device, an estimated blood-pressure waveform representing an estimated blood pressure of the subject, according to a predetermined relationship between blood-pressure waveform and pulse wave; and

a waveform-displaying control means for operating, when the blood-pressure waveform detected by the blood-pressure-waveform-detecting device is not abnormal, the display device to display the blood-pressure waveform, and operating, when the blood-pressure waveform is abnormal, the display device to display the estimated blood-pressure waveform in place of the blood-pressure waveform.

2. An apparatus according to claim 1, wherein the pulse-wave detecting device comprises a photoelectric-pulse-wave detecting device which is adapted to be worn on the third portion of the subject, emits a light toward the third portion, and detects a photoelectric pulse wave from the third portion.

3. An apparatus according to claim 1, wherein the waveform-displaying control means judges that the blood-pressure waveform is abnormal, when the pressure of the cuff is not lower than a prescribed lowest pressure at which the cuff would at least partly block a flow of blood through the first portion of the subject, and thereby operates the display device to display the estimated blood-pressure waveform.

4. An apparatus according to claim 2, wherein the photoelectric-pulse-wave detecting device comprises a reflection-type photoelectric-pulse-wave detecting device which detects the photoelectric pulse wave based on the light reflected from the third portion.

5. An apparatus according to claim 2, wherein the photoelectric-pulse-wave detecting device comprises a transmission-type photoelectric-pulse-wave detecting device which detects the photoelectric pulse wave based on the light transmitted through from the third portion.

6. An apparatus according to claim 1, further comprising a relationship determining means for determining the relationship between blood-pressure waveform and pulse wave, based on the blood-pressure waveform detected by the blood-pressure-waveform detecting device and the pulse wave detected by the pulse-wave detecting device.

7. An apparatus according to claim 1, wherein the blood-pressure determining device comprises:

a cuff-pressure changing device which changes the pressure of the cuff;

a cuff-pressure sensor which detects the pressure of the cuff;

a cuff-pulse-wave detecting device which extracts, from the pressure detected by the cuff-pressure sensor, a cuff pulse wave occurring to the cuff while the pressure of the cuff is changed by the cuff-pressure changing device; and

a blood-pressure determining means for determining the blood pressure of the subject based on the cuff pulse wave detected by the cuff-pulse-wave detecting device while the pressure of the cuff is changed by the cuff-pressure changing device.

8. An apparatus according to claim 1, wherein the blood-pressure-waveform detecting device comprises:

a pressure-pulse-wave sensor which is adapted to be pressed against an artery of the second portion of the subject via a skin of the second portion, and continuously detects a pressure pulse wave produced from the artery;

a relationship determining means for determining a relationship between blood pressure and pressure pulse wave, based on the blood pressure determined by the blood-pressure determining device and the pressure pulse wave detected by the pressure-pulse-wave sensor; and

blood-pressure-waveform determining means for determining, according to the relationship determined by the relationship determining means, the blood-pressure waveform based on the pressure pulse wave detected by the pressure-pulse-wave sensor.