CALIBRATION OF SEGMENTAL BLOOD VOLUME CHANGES IN ARTERIES AND VEINS FOR PULSE VOLUME RECORDERS

摘要

The calibration device includes a controllable pneumatic pump (44), a pressure sensor (48), a computerized device (72) for determining when a representative number of blood volume change signals are substantially similar and thereafter generating a calibration signal. The calibration system also includes a device which changes the volume in the closed peumatic system by a predetermined calibrated amount in the presence of the calibration trigger signal. This volume changing device may be a series of valves (V1, V2) coupled by a chamber (50) having a known volumetric size or a positive displacement pump driven by a stepper motor. The calibration system also includes a computerized device for correcting representative blood volume change signals based on the pressure signals at each discrete level of cuff pressure as corrected by the calibration signals represented by detected pressure signals obtained substantially simultaneously with the change of the volume at each discrete level of cuff pressure.