Fluid transfer device may be configured as a vacuum pump, including blood and blood constituents. Fluid transfer device used for assisting in the pumping of blood through a patient's heart for reducing the load on the patient's heart, sheer forces and blood pressure on the inner walls of the heart are reduced. Pump may be used as an implanted cardiac assist device, such as an aortic assist device, a ventricular assist device, or as a complete artificial heart. By use of a vacuum, the inventive fluid transfer device may be operated at no more than atmospheric pressure. A pre-charged pressure tank may be used dependent on the application requirements, such as in the case where fluid pressure of the pumped fluid, including the backpressure of body fluids, in the case where pressure greater than atmospheric to sufficiently expel pumped fluid.
