Oxygenation of the blood, elimination of carbon dioxide, and maintenance of circulation by means of a pump that has the effect of ventricular contractions constitute the objectives in mechanical substitution for the lungs and heart. A review of the physiological details involved in the development of substitutes for the lungs and the heart is beyond the scope of this report and will therefore not be attempted. Furthermore, the contributions of Kolff, Jongbloed, Bjork, Gibbon, and Dennis have already furnished answers to many of the basic problems involved in extracorporeal oxygenation and circulation.
Recent reports of work done in this field seem to have led many practitioners to believe that the use of a mechanical heart-lung machine for total by-pass during intracardiac surgery is an imminent possibility. However, the logical steps in the evolution of such physiological-mechanical systems must still include experiments designed to measure the machine's effects when used on