Evaluation of extracorporeal blood heat exchanger devices.

An accurate and easy to use test circuit has been developed for the performance evaluation of the heat exchangers used in cardiac surgery during extracorporeal circulation. The water part of the heat exchanger is fixed at a flow rate of 15 l/min and at a temperature of 40 degrees C. In the blood side, the flow rate is varied from 1 to 6 l/min and the temperature is 30 degrees C. The use of a precise thermometer (precision 0.01 degrees C) and of a microcomputer permits efficiency with a good reproducibility. The results obtained show a real improvement in the efficiency of the new extracorporeal blood heat exchangers devices.