A Method for the Study of the Circulation in the Dog Using a Mechanical Left Ventricle

In this article, Freis and several members of the faculty at the Georgetown University Hospital provided a detailed description of a pump which could replace the left ventricle in dogs. The pump, a smaller and simpler alternative to larger pumps that replace the entire heart, allowed for independent pump rate and stroke volume, and thus could enable researchers to isolate the responses of the cardiovascular system to controlled changes in left ventricular output.