From a review of the many and varied attempts to date to design a successful cardiac prosthesis, it was shown that 1) every attempt to design a ventricular actuating mechanism (the crucial element in a cardiac prosthesis) has failed to satisfy one or more of the design requirements and has thus resulted in a maximum survival time for an animal on a cardiac prosthesis of 247 hours and, 2) by combining the operating principles of two previously developed actuating mechanisms (spring-driven and rotating shaft-driven), a successful design could be the possible result. A description of the design and construction of a prototype of such a hybrid configuration was next presented. The mechanism presented in the study was then briefly evaluated with respect to its ability to 1) self-regulate its pump output and, 2) produce a physiological aortic pressure/time waveform. Results of the study demonstrated that the pump was capable of producing a quasi-physiological pressure/time waveform. Self regulatory ability was proven to be ineffective. / Master of Science