Design of atrial cuff for the undulation pump total artificial heart

Background: The implantable total artificial heart (TAH) is the final goal of artificial heart research. Although various types of implantable TAH are under development in several countries, a more compact TAH is required. In our laboratory, an undulation pump (UP) TAH has been in development for 6 years. The UPTAH is the most compact TAH in the world. It could be implanted into the chest cavity of a goat weighing between 41 and 79 kg. However, the design of atrial cuff of the UPTAH is very important in order to ensure a good fit, low flow resistance and good blood compatibility in the narrow chest cavity of the goat. The objective of this study is to establish design criteria for the atrial cuff of the UPTAH. Methods: The predominant parameters of the atrial cuff to ensure a good fit, blood compatibility and atrial wall suction protection are: (1) cuff diameter (D), (2) configuration (h) (flat to cone shape), (3) angle to the pump nozzle (α) and (4) angle to the UP (β). In this study, many types of atrial cuff were designed by changing these parameters. Results: Nine types of atrial cuff model were designed and fabricated through animal experiments with goats. The final parameters for optimum design of the atrial cuff were as follows: D = 38 mm, h = 18 mm, α = 40° (R), 30° (L), β = 30°. Discussion: The atrial cuff design is one of the most important key points for good fit, good blood compatibility and good pump performance in the implantable TAH. However, until now few papers have been published concerning the cuff design. As a result of various trials, we were able to finalize the design of the atrial cuff for our UPTAH.