Development of a universal second generation pneumatic ventricular assist device and drive unit

This paper describes a pneumatic ventricular assist device designed to be used for any circulatory support application including RVAD, LVAD, or BIVAD, trans-operative, short-term or long-term, tethered implantable or extracorporeal. It consists of a contoured pumping shell and a supple and elastic silicon blood-sac/valve assembly specially designed to allow continuous and fluid movement of blood and to limit blood-contacting surfaces. The components can be inexpensively and reliably manufactured by injection molding. Its design facilitates priming, de-bubbling, and connection to the body. The driver, powered by pressurized air or oxygen, commonly available in hospital rooms, intensive care units and operating rooms, is also described. The driver can provide both blood-ejecting pressure (systole) and blood-filling vacuum (diastole) to the VAD. Pumping is controlled by a computer by means of pressure and volume sensors, and electromechanical valves. Ventricular pumping is performed by a single spring-loaded piston. The computer can actively regulate maximum systolic ventricular pressure, maximum diastolic vacuum, cycling rate and/or ejection volume (depending on the operating mode). The absence of a motor or electrical pump make the device small, easy to handle, and less expensive. A first prototype of the proposed system was tested in vitro and results are presented.