Blood-pressure measuring apparatus

Abstract

An apparatus for measuring a systolic blood pressure of a living subject, including an inflatable cuff which is adapted to be wound around a body portion of the subject and includes a first inflatable bag which is inflatable to press an artery of the body portion, a first amplitude determining device for determining a first amplitude of each of a plurality of heartbeat-synchronous pulses of a first pulse wave which is produced in the first inflatable bag when a pressure in the first bag is changed, a pulse-wave detecting device which detects a second pulse wave which propagates from the artery to a downstream-side portion of the cuff as seen in a blood-flow direction in which blood flows in the artery, a second amplitude determining device for determining a second amplitude of each of a plurality of heartbeat-synchronous pulses of the second pulse wave which is detected by the pulse-wave detecting device when the pressure of the first inflatable bag is changed, a ratio calculating device for calculating a ratio of one of each of the first amplitudes determined by the first amplitude determining means and each of the second amplitudes determined by the second amplitude determining means to the other of the each of the first amplitudes and the each of the second amplitudes, and a blood-pressure determining device for determining the systolic blood pressure of the subject, based on the ratios calculated by the ratio calculating device.

Dependencies are inferred from the claim text.