Patent ID: 6346083
Filing Date: 2002-02-12
Classification: A61B

Abstract:
A blood-pressure measuring apparatus, comprising:an inflatable cuff which is adapted to be wound around a body portion of a living subject and which includes a first inflatable bag which is inflatable to press an arterial vessel of the body portion and stop flow of blood in the arterial vessel; a first pulse-wave detecting device which detects a first pulse wave which is produced from the arterial vessel and is propagated to the first inflatable bag of the cuff wound around the body portion, the first pulse wave including a plurality of heartbeat-synchronous pulses; a second pulse-wave detecting device which detects a second pulse wave which is produced from the arterial vessel and is propagated to a downstream-side portion of the cuff wound around the body portion as seen in a direction in which the blood flows in the arterial vessel, the second pulse wave including a plurality of heartbeat-synchronous pulses; amplitude correcting means for correcting at least one of (a) a first group of respective amplitudes of the heartbeat-synchronous pulses of the first pulse wave detected by the first pulse-wave detecting device and (b) a second group of respective amplitudes of the heartbeat-synchronous pulses of the second pulse wave detected by the second pulse-wave detecting device, so that at least one amplitude of the first group that corresponds to at least one heartbeat-synchronous pulse of the first pulse wave that is detected by the first pulse-wave detecting device while the flow of the blood in the arterial vessel is stopped by the first inflatable bag is substantially equal to at least one amplitude of the second group that corresponds to at least one heartbeat-synchronous pulse of the second pulse wave that is detected by the second pulse-wave detecting device while the flow of the blood in the arterial vessel is stopped by the first inflatable bag; amplitude-difference determining means for determining a difference between each of the amplitudes of the first group and a corresponding one of the amplitudes of the second group after said at least one of the first and second groups is corrected by the amplitude correcting means; and blood-pressure determining means for determining a blood pressure of the subject based on the difference between said each of the amplitudes of the first group and said corresponding one of the amplitudes of the second group.