DETERMINING METHOD FOR CONTROL TARGET VALUE IN CONTINUOUS SPHYGMOMANOMETER

摘要

PURPOSE:To obtain a measured value of high accuracy even in the case a fluctuation is large due to individual difference of photoelectric pulse wave amplitude and a state of the body by approximating a photoelectric pulse wave by a tertiary correlation curve, and setting an average value of the photoelectric pulse wave at the maximum point derived from this correlation curve as a control target value. CONSTITUTION:In a pressure ascending process of a cuff 1, a photoelectric pulse wave signal for showing a capacity fluctuation which follows a blood pressure pulsative variation of a finger of a person to be examined is detected by a pressure sensor 7, and an amplitude value of every prescribed time or every one pulse and an average value of that time are stored in a memory of a control CPU circuit 15 through an A/D converter 13. After these data are taken completely, pressure is reduced gradually by operating a pressure supply means 5 and a solenoid valve 3. Thereafter, based on a data group stored in the memory of the control CPU circuit 15, a tertiary correlation curve being approximate to a photoelectric pulse wave is calculated, an average value of the photoelectric pulse wave is derived from the maximum point of this correlation curve, and this value is set as a control target value. Subsequently, pressure applied to a finger is controlled by the pressure supply means 5 and the solenoid valve 3 so that an output signal of a photodetecting means 21 becomes this control target value, and a pressure waveform of this time is read as a blood pressure waveform of a person to be examined.