Studies on multilayer membrane artificial lung.

Studies were carried out to devise a new multilayer membrane artifiilal lung. It was determined from the present studies on flow patterns and dye clearance that the basic design of the multilayer membrane artificial lung should have one-inlet and one-outlet and be elliptic in shape. Many little projections were made on both surfaces of a distributing mat in order to support membranes and to give turbulences to the flowing blood. Distance between two membranes or the thickness of the blood layer was determined to be 0.8-0.9 mm. Fifty Hs silicon rubber was used as material for the distributing mats in order to prevent blood leakage from between the membranes. Silicon rubber membrane and Teflon membrane were investigated for gas permeability by using a model of the elliptic artificial lung and a model of the Peirce-Galletti's a rtificial lung. Nineteen mongrel dogs were subjected to the studies. Phycon membrane or silicon rubber membrane, made in Japan, showed an excellent gas exchange capability and proved to be the best membrane now available. One unit of the artificial lung comprises two mats and two membranes, having an oxygenating surface area of 1540 cm2• This elliptic membrane artificial lung with a stack of t en oxygenating units has approximately 60 ml/ min of oxygen upta ke when Phycon membrane is used, and can be applied to total cardiopulmonary bypass for infants and small children.