| 摘要 |
<p>A pneumatic pump comprises two coaxial cylindrical pumping chambers, each enclosing a piston connected to the other through a partition by a tube, thereby forming a monolithic piston assembly that is driven axially by a common electrical actuator providing reciprocating motion. The volume in the bottom chamber is selected as needed to provide the desired pressure in the left ventricle of an artificial heart driven by the pump. The diameter of the tube connecting the pistons is selected such that the stroke volume of the top chamber is reduced with respect to that of the bottom chamber as needed to match the reduced pressure requirements of the right ventricle of the artificial heart. Check valves are used in each chamber to ensure venting of excess pressure during the blood ejection phase and to limit the vacuum during the fill phase.</p> |
