| Abstract | Remarkable improvement in recent open-heart surgery is mainly due to advanced techniques of ECC using an artificial heart and lung machine. However, surgical results for infants may not be satisfactory. This is basically because the internal organs of infants are still immature physiologically as well as anatomically, which causes excessive fluid shift into extracellular tissues, resulting in generalized edema. Because of immature growth of the internal organs, more physiological perfusion is required for ECC in infants. It has been reported in several papers that pulsatile perfusion is superior to a conventional nonpulsatile perfusion from the physiological point of view, although there are many uncertainties regarding both types of perfusion. Nevertheless, the perfusion method presently used for an infant is the same type as for an adult with few modifications of the conventional heart and lung machine. There is another problem for a conventional heart and lung machine. It requires an operator to manage the perfusion control manually. Because of less priming blood volume for an infant ECC, a precisely controlled perfusion is extremely important, which might occasionally be beyond human control. Several workers have tried automatic control of an artificial heart and lung machine without much successful clinical use. Concerning these problems, we have been developing for use in infants an advanced ECC system with automatically controlled blood perfusion.
[The system described is composed of roller pumps, sensors, A/D convertors, and (apparently) an Apple II microcomputer based on the Rockwell 6502.] |