A novel single occluder mechanical heart valve (1, 45) that exhibits reduced closing cavitation and potential blood-damaging hemolysis by utilizing guiderails (14, 54) to create a continuously shifting pivot axis to control hydraulic forces so as to minimize tangential velocity of the occluder (3, 53) at the instant of final closing. These forces are also used to effect a quick initial closing movement from the full open position. In the same way, other guiderails (12, 16, 52, 56) are employed to provide a quick opening response while guiding the occluder (3, 53) to its full open position where to two fairly equal flow channels are created.
