Development of an affordable diaphragmatic pump for cardiopulmonary bypass: An in vivo evaluation

A new diaphragmatic pump (L-Y pump) and its drive unit were developed in ou r institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess a nd confirm the function and controllability of this pump, comparative studi es of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable an d within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences betw een the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin le vels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/d l in the L-Y pump group, and minimal hemolysis was indicated. In conclusion , this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy man ipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.