A new prototype model of a flow-transformed pulsatile total artificial heart (FTPTAH), which consists of one undulation pump (UP; formerly known as a precessional displacement pump; PDP), four jellyfish valves, and a flexible membrane has been developed. Flow transformation between pulmonary and systemic circulation is brought about by the switching direction of motor rotation, so that no electrical flow switching valve is needed. The undulation pump is a continuous flow pump, and it can also be driven as a reversible pump. A prototype model perfused 3.01/min alternately in the pulmonary and systemic circulations with pulsatile flow in a mock circulatory system. A compensatory chamber has been designed, with the objective of preventing deoxygenated blood from being sent to the systemic circulation. The chamber is formed by a flexible membrane located between immediately in front of the mitral valve and immediately behind the tricuspid valve. Its volume is nearly equal to the priming volume of the undulation pump. Deoxygenated blood present in the undulation pump at the end of pulmonary circulation is stored in the compensatory chamber by shifting the flexible membrane to the direction of the left atrium, thus preventing the deoxygenated blood from being sent to the systemic circulation.