Pneumatic drives are being employed extensively at present for devices that completely replace the pumping function of a heart. They utilize the physical properties of compressed air as an energy medium. The traditional pneumatic scheme of such a drive has two independent units that separately control the lefthand and right-hand artificial ventricles of the heart, and each of these units contains a pneumatic station and its own pneumatic drive. The pneumatic station includes a compressor, a vacuum-pump and a receiver. The pneumatic drive contains pressure and vacuum regulators, and also a pneumatic distributor that makes connections, in accord with signals from a control system, to the pneumatic chamber of an artificial ventricle or to an excess-pressure channel, or to a vacuum channel. One way to improve a pneumatic drive would be the functional and structural combination of one or another of the subassemblies and units. Thus, for example, a compressor is used as a source of excess pressure and of vacuum. Another variant would be a combination of a pneumatic distributor and a compressor. In this case the drive for a device that replaces the pumping function of the heart is realized in the form of a piston-type compressor where the cavity under the piston is connected with the pneumatic chamber of the pumping arrangement. Such construction makes it possible to do without a pneumatic distributor, the regulators, and receivers. However, the large inertia of the piston's mass substantially reduces the operating speed of a drive or causes substantial expenditures of energy to control it. Upon comparing the known control methods for an artificial heart it is possible to distinguish two basic trends. In the first, blood is moved by connecting the energy source periodically to the left-hand and right-hand ventricles of the heart in phase with the systole, and in this case the capacity of the output drive should be equal to the sum of the instantaneous capacities for both ventricles. In the second method the energy stored in accumulators (receivers) is moved periodically to the left-hand and right-hand ventricles. In this case the output capacity of the pressure source should be equal to the sum of the average capacities of the left-hand and right-hand pumping arrangements in the systolic phase. Thus, from the standpoint of energy expenditure the second method of controlling the operation of an artificial heart is more favorable. A typical feature of a pneumatic drive for pneumatic-drive apparatus that replaces the pumping function of a heart, that is implemented by a piston-type compressor, and that realizes the first control method is that at the end of a systolic phase the volume of the piston chamber and the volume of the pneumatic chamber of an artificial ventricle constitute an accumulator in which some energy of the compressed gas is stored. This energy can perform useful work. In an ideal, piston-type compressor for which the force of friction is negligible and the thermodynamic processes are isothermal, the increase in the piston chamber AV because of the energy of the compressed gas can be found from the following expression: