Vacuum generation in pneumatic artificial heart drives with a specially designed ejector system.
To improve the filling characteristics of pneumatically driven membrane artificial hearts (AHs), a vacuum is applied during diastole. This paper describes an ejector system for AH-drivers based on the Venturi effect, which was designed for this purpose. It provides vacuums of more than -40 mmHg at flow rates up to 50 l/min requiring a supplying primary gas pressure of less than 150 kPa (1140 mmHg). Under normal working conditions, the necessary supply flow was less than 5l/min. The device is small, cheap, quiet and fail-safe, and has been evaluated successfully in experimental and clinical use.
Schima
H
H
Second Department of Surgery, University of Vienna, Austria.
Huber
L
L
Spitaler
F
F
D006354:Heart, Artificial; D006801:Humans; D011474:Prosthesis Design; D014618:Vacuum