Determination of flow resistance (vascular tone) by a perfusion pump method

Summary

A pump was designed for measurement of the resistance (tone) of vessels by the method of perfusion, by way of the stable minute blood volume, taken from the animal undergoing the measurement (autoperfusion), or from a donor. The pump maintains a stable output.

The pump provides the pulsation of perfusion pressure with the frequency of 90, 120, 150, 180, 240 and 300 per minute. When perfusion pressure is more than 300 Hg the pump automatically stops.

The apparatus consists of three separate units; the drive, the removable working head and the resistering mercury manometer.

This is attained by: a) ensuting rigidity of the hydraulic drive, and b) using distantly controlled external electromagnetic valves with a range of output regulation of from 3 to 120 ml per minute. The volume of blood contained in the pump is 6 to 8 ml.