An artificial heart could be constructed of an internal flow system surrounded by an external pressure system. Separating the two systems would give more freedom to the designers to achieve streamlined blood flow and exact duplication of the natural heart’s pressure volume characteristics.
The internal flow system would consist of four streamlined balloons with valves. Each auricle and ventricle would be represented by one balloon. The balloons would expand and contract to pump, according to the pressure of the gas or other fluid surrounding them. A different pressure chamber would be needed for each balloon. There being less design constraints imposed by the need of the balloon to pump, a more streamlined shape could be employed, less likely to damage blood cells.
The external pressure system would consist of four pressure chambers containing gas or other fluid. The pressure of each one being regulated by a computer controlled piston. There being no design constraints on the piston’s movement, an exact duplication of the natural heart’s pressure volume characteristic could be achieved. (Perhaps the pressure could be sensed in the aorta.) This should lead to fewer complications in a little known field.
Some of the mechanical components need not be mounted in the chest, as the inside of the pistons could be connected to the outside of the balloons by hoses.