Fluid pressure generating means

Abstract

A fluid pressure generating means ( 10 ) for a heart assist device having blood pumping means. The pressure generating means ( 10 ) includes a housing ( 11 ), defining an interior volume ( 18 ), and having a substantially rigid first housing portion ( 12 ), a substantially rigid second housing portion ( 14 ), a flexible third housing portion ( 16 ) extending between the first ( 12 ) and second ( 14 ) housing portions and an inlet/outlet port ( 15 ) adapted for fluid communication with the blood pumping means. The pressure generating means ( 10 ) also includes a fluid filling the housing and a motor ( 20 ) disposed within the housing ( 11 ) and connected between the first ( 12 ) and second ( 14 ) housing portions. Actuation of the motor ( 20 ) moves the first ( 12 ) and second ( 14 ) housing portions relative to one another to generate fluid pressure changes at the inlet/outlet port ( 15 ). A related heart assist device and method for the treatment of congestive heart failure, myocardial ischemia and like conditions are also disclosed.

the following is claimed: 
     
         1 . In a heart assist device adapted to be implanted in a patient, improvement including:
 (a) a blood pumping means that will, when actuated cause or assist the movement of blood around the patient's vasculature;   (b) a fluid reservoir; and   (c) fluid pressure generating means adapted to pump fluid between the reservoir and the blood pumping means, wherein the fluid reservoir and the fluid pressure generating means are adapted to be disposed in the right pleural cavity of the patient directly adjacent to the patient's heart and to be connected only to surrounding soft tissue.   
     
     
         2 . A heart assist device including:
 a blood pumping means adapted, when actuated, to cause or assist the movement of blood around the patient's vasculature;   a fluid reservoir; and   a fluid pressure generating means driven by an electric motor and adapted to pump a liquid from the fluid reservoir to the blood pumping means,   wherein the electric motor has a cogging torque with is sufficiently low that the natural systolic blood pressure of the patient is sufficient to cause liquid in the blood pumping means to be returned to the fluid reservoir in the event that the electric motor stops.