Blood-pressure measuring apparatus
First Claim
1. An apparatus for measuring a blood pressure of a living subject, comprising:
- an inflatable cuff which is adapted to be worn on a body portion of the subject and which applies a pressure to the body portion of the subject;
a cuff-pressure changing device which changes the pressure of the cuff between a first pressure lower than a systolic blood pressure of the body portion of the subject and higher than a mean blood pressure of the body portion, and a second pressure lower than a diastolic blood pressure of the body portion;
a blood-pressure determining device which determines a diastolic blood pressure and a mean blood pressure of the subject based on a heartbeat-synchronous signal which is detected from the subject while the cuff-pressure changing device changes the pressure of the cuff;
a cuff-pulse-wave detecting device which detects a cuff pulse wave as an oscillation of the pressure of the cuff;
a pulse-wave-magnitude determining means for operating the cuff-pressure changing device to maintain the pressure of the cuff at a third pressure lower than the mean blood pressure of the body portion of the subject, and determining a minimal magnitude, a mean magnitude, and a maximal magnitude of the cuff pulse wave detected by the cuff-pulse-wave detecting device in a state in which the pressure of the cuff is maintained at the third pressure; and
a systolic-blood-pressure determining means for determining a systolic blood pressure of the subject, based on the diastolic and mean blood pressure determined by the blood-pressure determining device and the minimal, mean, and maximal magnitudes of the cuff pulse wave determined by the pulse-wave-magnitude determining means, according to a fact that the minimal, mean, and maximal magnitudes of the cuff pulse wave correspond to the diastolic, mean, and systolic blood pressure of the subject, respectively.
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Accused Products
Abstract
A blood-pressure measuring apparatus including a cuff worn on a body portion of a subject to apply a pressure to the body portion; a changing device which changes the cuff pressure; a determining device which determines a diastolic and mean blood pressure of the subject; a detecting device which detects a cuff pulse wave as an oscillation of the cuff pressure; a pulse-wave-magnitude determining device for operating the changing device; and a systolic-blood-pressure determining device for determining a systolic blood pressure of the subject, based on the determined diastolic and mean blood pressure and the determined minimal, mean, and maximal magnitudes of the cuff pulse wave, according to a fact that the minimal, mean, and maximal magnitudes of the cuff pulse wave correspond to the diastolic, mean, and systolic blood pressure of the subject, respectively.
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Citations
8 Claims
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1. An apparatus for measuring a blood pressure of a living subject, comprising:
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an inflatable cuff which is adapted to be worn on a body portion of the subject and which applies a pressure to the body portion of the subject;
a cuff-pressure changing device which changes the pressure of the cuff between a first pressure lower than a systolic blood pressure of the body portion of the subject and higher than a mean blood pressure of the body portion, and a second pressure lower than a diastolic blood pressure of the body portion;
a blood-pressure determining device which determines a diastolic blood pressure and a mean blood pressure of the subject based on a heartbeat-synchronous signal which is detected from the subject while the cuff-pressure changing device changes the pressure of the cuff;
a cuff-pulse-wave detecting device which detects a cuff pulse wave as an oscillation of the pressure of the cuff;
a pulse-wave-magnitude determining means for operating the cuff-pressure changing device to maintain the pressure of the cuff at a third pressure lower than the mean blood pressure of the body portion of the subject, and determining a minimal magnitude, a mean magnitude, and a maximal magnitude of the cuff pulse wave detected by the cuff-pulse-wave detecting device in a state in which the pressure of the cuff is maintained at the third pressure; and
a systolic-blood-pressure determining means for determining a systolic blood pressure of the subject, based on the diastolic and mean blood pressure determined by the blood-pressure determining device and the minimal, mean, and maximal magnitudes of the cuff pulse wave determined by the pulse-wave-magnitude determining means, according to a fact that the minimal, mean, and maximal magnitudes of the cuff pulse wave correspond to the diastolic, mean, and systolic blood pressure of the subject, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
an air pump which supplies a compressed air;
a pressure control valve which receives the compresses air from the air pump and controls the pressure of the cuff; and
a control means for controlling the air pump and the pressure control valve to change the pressure of the cuff.
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7. An apparatus according to claim 1, wherein the blood-pressure determining device comprises:
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a pressure sensor which detects the pressure of the cuff that contains the oscillation as the cuff pulse wave;
a static-pressure filter circuit which extracts, from the cuff pressure containing the oscillation, a static pressure free of the oscillation; and
a determining means for determining the diastolic and mean blood pressure of the subject based on the heartbeat-synchronous signal and the static pressure extracted by the static-pressure filter circuit.
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8. An apparatus according to claim 7, wherein the cuff-pulse-wave detecting device comprises a pulse-wave filter circuit which extracts, from the cuff pressure containing the oscillation, the oscillation as the cuff pulse wave.
Specification