Blood pump

A fluid pump comprising, an elastic bladder, at least a portion of the interior surface area of said bladder being changeable between a contracted state having a first surface area and an expanded state having a second surface area that is substantially greater than said first surface area, said bladder having a fluid inlet and a fluid outlet;

• a housing around at least a portion of said bladder and defining a space between said housing and said bladder for receiving a bladder actuating fluid;
• means for alternately increasing and decreasing the pressure of said actuating fluid for alternately expanding and contracting said bladder to change the interior surface area and volume of said bladder;
• means for causing substantially one-way fluid flow through said bladder;
• and
• wherein said bladder and said actuating fluid are a unitary body of semisolid material, the surface of said semisolid material functioning as said bladder interior surface.

A method of pumping blood in the circulatory system of a human in the need thereof comprising the steps of

• (a) providing a blood pumping system having an extensible and contractible bladder, said pumping system having an inlet and an outlet;
• (b) connecting the inlet and outlet of said pumping system to the human's circulatory system;
• (c) expanding a majority of the interior surface area of said pumping system by at least a few percent, including expanding the volume of the bladder to draw blood into the bladder through the inlet;
• (d) contracting a majority of the interior surface area of said blood pumping system by at least a few percent, including contracting the volume of the bladder to pump blood out of the outlet of said system;
• and
• (e) rhythmically repeating steps (c) and (d).

A fluid pump comprising:

• a bladder, at least a portion of the interior surface area of said bladder being changeable, said bladder having a fluid inlet and a fluid outlet, said bladder having thickness variations for controlling the expansion and contraction of said bladder, said bladder have a thinner wall thickness at said inlet and a thicker wall thickness at said outlet;
• means for alternately expanding and contracting said bladder to change the interior surface area and volume of said bladder;
• and
• means for causing substantially one-way fluid flow through said bladder.

A fluid pump comprising:

• a bladder, at least a portion of the interior surface area of said bladder being changeable, said bladder having a fluid inlet and a fluid outlet;
• means for alternately expanding and contracting said bladder to change the interior surface area and volume of said bladder;
• means for causing substantially one-way fluid flow through said bladder;
• and
• at least one extensible strut spanning the interior of said bladder for controlling its expansion and contraction.

A fluid pump comprising:

• a bladder, at least a portion of the interior surface area of said bladder being changeable, said bladder having a fluid inlet and a fluid outlet;
• means for alternately expanding and contracting said bladder to change the interior surface area and volume of said bladder;
• means for causing substantially one-way fluid flow through said bladder;
• and
• one or more bands on said bladder for controlling its expansion and contraction.

A fluid pump comprising:

• a housing;
• an extensible and contractible bladder in said housing, a space defined between said housing and said bladder for receiving a bladder driving fluid, said bladder having an inlet and an outlet;
• a check valve to at least one of said bladder inlet and outlet;
• means for altering the pressure of the driving fluid to alternately expand and contract the interior surface area and volume of said bladder to define a pumping cycle, most of said interior surface area of said bladder adapted to expand and contract with each said pumping cycle;
• and
• a fluid pressure regulator in said space to selectively control the rate of expansion or contraction of selected areas of said bladder.

A fluid pump comprising:

• a bladder, at least a portion of the interior surface area of said bladder being changeable, said bladder having a fluid inlet and a fluid outlet;
• means for alternately expanding and contracting the bladder to change the interior surface area and volume of said bladder;
• means for causing substantially one-way fluid flow through said bladder;
• and
• wherein said bladder is comprised of a plurality of different materials to control the rate of expansion or contraction of selected areas of said bladder.