Oscillometric automatic blood-pressure measuring apparatus

• US 20030097074A1
• Filed: 11/04/2002
• Published: 05/22/2003
• Est. Priority Date: 11/19/2001
• Status: Active Grant

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Corporation (Fukuda Denshi Company Limited)
• Inventors: Oka, Tohru, Yokozeki, Akihiro
• Granted Patent: US 6,808,496 B2
• Time in Patent Office: Days
• US Class Current: 600/490
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors

Abstract

An oscillometric automatic blood-pressure measuring apparatus, including an inflatable cuff which is adapted to be wound around a portion of a living subject, so as to detect respective amplitudes of a plurality of heartbeat-synchronous pulses of a cuff pulse wave as an oscillatory component that is produced in the cuff in synchronism with heartbeats of the subject in a cuff-pressure change process in which a cuff pressure as a pressure in the cuff is changed, a cuff-pulse-wave-amplitude correcting device for correcting the respective amplitudes of the respective pulses of the cuff pulse wave, according to a predetermined non-linear relationship between difference between cuff pressure and subject'"'"'s mean blood pressure, and amplitude of cuff pulse wave, and a blood-pressure determining device for determining a blood pressure of the subject based on a change of the corrected amplitudes of the cuff pulse wave.

Claims

1. An oscillometric automatic blood-pressure measuring apparatus, comprising:

an inflatable cuff which is adapted to be wound around a first portion of a living subject, so as to detect respective amplitudes of a plurality of heartbeat-synchronous pulses of a cuff pulse wave as an oscillatory component that is produced in the cuff in synchronism with heartbeats of the subject in a cuff-pressure change process in which a cuff pressure as a pressure in the cuff is changed;

a cuff-pulse-wave-amplitude correcting means for correcting the respective amplitudes of the respective pulses of the cuff pulse wave, according to a predetermined non-linear relationship between difference between cuff pressure and subject'"'"'s mean blood pressure, and amplitude of cuff pulse wave; and

a blood-pressure determining means for determining a blood pressure of the subject based on a change of the corrected amplitudes of the cuff pulse wave.

4. An apparatus according to claim 1, wherein the blood-pressure determining means determines at least one of a systolic blood pressure and a diastolic blood pressure of the subject based on at least one change of the corrected amplitudes of the cuff pulse wave.

5. An apparatus according to claim 1, further comprising a cuff-pressure sensor which detects the cuff pressure as the pressure in the cuff.

6. An apparatus according to claim 1, further comprising a cuff-pulse-wave detecting device which detects, from the cuff, the respective heartbeat-synchronous pulses of the cuff pulse wave as a first volumetric pulse wave.

7. An apparatus according to claim 6, further comprising:

a second-volumetric-pulse-wave detecting device which is worn on a second portion of the subject and which detects, from the second portion, a plurality of heartbeat-synchronous pulses of a second volumetric pulse wave; and

a first-correction-factor determining means for determining, based on respective amplitudes of the respective pulses of the second volumetric pulse wave, respective first correction factors which can modify the respective amplitudes of the respective pulses of the second volumetric pulse wave, to a single value, and accordingly correct the respective amplitudes of the respective pulses of the cuff pulse wave as the first volumetric pulse wave.

8. An apparatus according to claim 7, further comprising a mean-blood-pressure determining means for determining a mean blood pressure of the subject based on the respective amplitude of the respective pulses of the cuff pulse wave that have not been corrected by the cuff-pulse-wave-amplitude correcting means, wherein the mean-blood-pressure storing device stores the mean blood pressure determined by the mean-blood-pressure determining means.

9. An apparatus according to claim 8, further comprising:

a mean-blood-pressure estimating means for estimating, based on the respective pulses of the second volumetric pulse wave detected by the second-volumetric-pulse-wave detecting device, respective estimated mean blood pressure values corresponding to the respective pulses of the cuff pulse wave as the first volumetric pulse wave; and

a second-correction-factor determining means for determining, according to the non-linear relationship determined by the relationship determining means, respective second correction factors which correct respective amplitude changes caused by respective deviations of the respective estimated mean blood pressure values corresponding to the respective pulses of the cuff pulse wave, from the mean blood pressure stored by the mean-blood-pressure storing device,

wherein the cuff-pulse-wave-amplitude correcting means corrects the respective amplitudes of the respective pulses of the cuff pulse wave, based on the first correction factors determined by the first-correction-factor determining means and the second correction factors determined by the second-correction-factor determining means.

10. An apparatus according to claim 1, further comprising a display device which displays the blood pressure of the subject determined by the blood-pressure determining means.

2. An oscillometric automatic blood-pressure measuring apparatus, comprising:

an inflatable cuff which is adapted to be wound around a first portion of a living subject, so as to detect respective amplitudes of a plurality of heartbeat-synchronous pulses of a cuff pulse wave as an oscillatory component that is produced in the cuff in synchronism with heartbeats of the subject in a cuff-pressure change process in which a cuff pressure as a pressure in the cuff is changed;

a pulse-wave detecting device which is worn on a second portion of the subject and which detects, from the second portion, a plurality of heartbeat-synchronous pulses of a pulse wave;

a pulse-pressure-correction-factor determining means for determining, based on respective amplitudes of the respective pulses of the pulse wave detected by the pulse-wave detecting device, respective pulse-pressure correction factors to correct respective pulse pressures corresponding to the respective amplitudes of the respective pulses of the pulse wave, to a single value;

a mean-blood-pressure storing device which stores a mean blood pressure of the subject;

a relationship determining means for determining, based on the mean blood pressure stored by the mean-blood-pressure storing device, a non-linear relationship between difference between cuff pressure and subject'"'"'s mean blood pressure, and amplitude of cuff pulse wave;

a mean-blood-pressure estimating means for estimating, based on the respective pulses of the pulse wave detected by the pulse-wave detecting device, respective estimated mean blood pressure values corresponding to the respective pulses of the cuff pulse wave;

a mean-blood-pressure-correction-factor determining means for determining, according to the non-linear relationship determined by the relationship determining means, respective mean-blood-pressure correction factors to correct respective amplitude changes corresponding to respective deviations of the respective estimated mean blood pressure values corresponding to the respective pulses of the cuff pulse wave, from the mean blood pressure stored by the mean-blood-pressure storing device;

a cuff-pulse-wave-amplitude correcting means for correcting the respective amplitudes of the cuff pulse wave, based on the respective pulse-pressure correction factors determined by the pulse-pressure-correction-factor determining means and the respective mean-blood-pressure correction factors determined by the mean-blood-pressure-correction-factor determining means; and

a blood-pressure determining means for determining a blood pressure of the subject based on a change of the corrected amplitudes of the cuff pulse wave.

3. An oscillometric automatic blood-pressure measuring apparatus according to claim 2, further comprising a temporary-mean-blood-pressure determining means for determining, as a temporary mean blood pressure of the subject, a cuff pressure corresponding to the greatest one of the respective amplitudes of the respective pulses of the cuff pulse wave by using an envelope defined by the amplitudes before correction, wherein the mean-blood-pressure storing device stores, as the mean blood pressure of the subject, the temporary mean blood pressure determined by the temporary-mean-blood-pressure determining means.