Cardiopulmonary bypass system-mountable anesthetic machine

Abstract

Miniaturization of the cardiopulmonary bypass (CPB) system may provide several benefits, such as decreasing the manpower, cost, and amount of homologous blood required and improving patient care. We have proposed a portable CPB system-mountable anesthetic machine. Our portable CPB system consists of a bypass circuit, a hard shell reservoir, a membrane oxygenator, and two pumps. The reservoir has three chambers, one venous and two suction chambers. These three chambers can control the negative pressure when connected with an ordinary vacuum system in the operating room. Pumps are used for perfusion and blood transfer from suction to venous chamber. We have been working to create a newly designed pump for this system. This pump consists of a polycarbonate rotor with six polyurethane vanes and acrylic acid resin housing. The housing is narrowed at both the inflow and outflow ports. This pump has characteristics of a vane pump as well as a friction pump. By using a DC brushless motor, it is possible to perfuse from 0.1 to 10 l/min, under bench testing. Preliminary animal tests of its operation produced very satisfactory results. Regarding hemolysis, the plasma free hemoglobin level was below 80mg/dl after 4h of operation using two pumps. This low-cost disposable CPB system enables it to be used for the portable CPB system-mountable anesthetic machine.