SPHYGMOMANOMETER BY PHOTOELECTRIC VOLUME PULSE WAVE

摘要

PURPOSE:To enhance the accuracy in measuring the blood pressure by inferring a cuff pressure from the first pulse wave component having an amplitude between the max. and standard amplitudes and the second pulse wave component having an amplitude smaller than that of the first pulse wave component but larger than the standard amplitude, which are extracted out of a photoelectric volume pulse wave. CONSTITUTION:For use as a finger sphygnomanometer, this instrument is provided with a cuff 10 for inserting a finger of the examined, a bladder 12 for pressing the arteries of the finger, a near infrared radiation LED 14 and a phototransistor 16. The cuff pressure is detected by a pressure sensor 22, the output from which is transmitted to a microprocessor 20 to detect a photoelectric volume pulse wave of the arteries of the examined by controlling variably the cuff pressure. The first pulse wave component having the first amplitude between the max. and standard amplitudes and the second pulse wave component having an amplitude smaller than the first amplitude of the first pulse wave component are extracted out of said photoelectric volume pulse wave to infer a cuff pressure when the amplitude of the photoelectric volume pulse wave is equal to the standard amplitude; the max. blood pressure is determined on the basis of such cuff pressure.