Steady state hemodynamic and energetic characterization of the Penn State/3M Health Care Total Artificial Heart

Total Artificial Heart (TAH) development at Penn State University and 3M He alth Care has progressed from design improvements and manufacturing documen tation to in vitro and in vivo testing to characterize the system's hemodyn amic response and energetic performance. The TAH system is completely impla ntable and intended for use as an alternative to transplantation. It includ es a dual pusher plate pump and rollerscrew actuator, welded electronics an d battery assembly, transcutaneous energy transmission system, telemetry, a nd a compliance chamber. In vitro testing was conducted on a Penn State moc k circulatory loop with glycerol/water solution at body temperature. Tests were performed to characterize the preload and afterload response, left atr ial pressure control, and power consumption. A sensitive preload response w as demonstrated with left atrial pressure safely maintained at less than 15 mm Hg for flow rates up to 7.5 L/min. Variations in aortic pressure and pu lmonary vascular resistance were found to have minimal effects on the prelo ad sensitivity and left atrial pressure control. In vivo testing of the com pletely implanted system in its final configuration was carried out in two acute studies using implanted temperature sensors mounted on the electronic s, motor, and energy transmission coil in contact with adjacent tissue. The mean temperature at the device-tissue interface was less than 4 degrees C above core temperature.