The analysis of hemodynamic parameters such as pressure and flow could give an indirect measure of total artificial heart (TAH) performance, but they do not directly reflect the problem areas in the design of the pump and response of the TAH performance to different pumping and operating conditions. Information concerning the intracyclic diaphragm motion and the relative performance of the prosthetic valves in a dynamic state need to be understood in order to produce consistent long-term animal survival.
The noninvasive technique of echography has been adapted to the functional analysis of a diaphragm - type TAH. Feasibility of the method is demonstrated, and its potential to provide a wealth of information regarding the operational characteristics of the dynamic components of the TAH is illustrated. A one-to-one correspondence between the response of the TAH components to various driving and operating conditions and the resulting echographs is brought forth to establish the present technique as an important, useful, and effective analytical tool. Dynamic motion of the diaphragm and the prosthetic valves is traced through a cardiac cycle to infer effective design feedback. Influence of parameters including afterloads and pulse rate on such motion is discussed.