Dynamic monitor of the cardiovascular system in weightlessness. Biosatellite experiment P-1059

摘要

The Pulse Wave Velocity Computer is designed to compute the ratio PWV = L/I (m/sec) where PWV is defined as the arterial pulse wave velocity, L equals the arterial length selected for measurement, and I equals the pulse transit time over the arterial length L. The computer calculates a PWV value for each pressure pulse produced by the heart, and provides a step-wise analog output signal proportional to the continuous PWV function. There are several ways to compute continuously the arterial PWV. All analog methods, however, can only approximate the reciprocal function involved, and so their accuracy is limited. The Pulse Wave Velocity Computer is conceived of as a laboratory test apparatus, for which repeatability is the prime concern. Accordingly, a digital time-measuring technique is combined with an analog dividing network, and the integral system elements are functionally separated so that they can be individually checked and calibrated.