Continuous noninvasive blood pressure measuring apparatus and method

Abstract

In a continuous noninvasive blood pressure measuring apparatus, a systolic pressure, diastolic pressure, and mean arterial pressure for calibration are measured according to the output of a pressure sensor, a cuff pressure is set lower than the diastolic pressure by a cuff pressure control section, and a reference pulse wave is obtained from the arithmetic means of a plurality of cuff pulse waves. A CPU calculates the peak value and the bottom value of the reference pulse wave, and a cuff pressure mean value corresponding to the D.C. component of the reference pulse wave, and further calculates coefficients which are used to allow the peak value, bottom value and cuff pressure mean value thus obtained to correspond to correspond to the systolic pressure, diastolic pressure, and mean arterial pressure, respectively. The CPU calculates according to the output of a temperature sensor a cuff pressure temperature compensation value for compensating for an amount of variation of the cuff pressure which varies with the temperature of the cuff. In addition, the CPU, while compensating the cuff pressure, which is read continuously, with the cuff pressure temperature compensation value, continuously calculates a blood pressure by utilizing the cuff pressure thus compensated, and the coefficients provided by the coefficient calculating section, and the cuff pulse waves read continuously.