Dialysis instrument with dialysate side pump for moving body fluids

A single access dialysis instrument, comprising:

• a single catheter for transmission of body liquids to and from the body;
• a reciprocating dialyzer with dialyzer membranes and having body liquid side disposed within said dialyzer membranes including means for defining a body fluid inlet and a body fluid outlet connected to said catheter, said reciprocating dialyzer further having a dialysate side disposed outside said dialyzer membranes including means for defining a dialysate inlet and a dialysate outlet, said body liquid side and said dialysate side separated by said dialyzer membranes, said dialyzer membranes being compliantly formed to expand and contract in response to a corresponding change in pressure between said body liquid and said dialysate within said dialyzer;
• storage means connected to said dialysate inlet and said dialysate outlet for holding a supply of liquid including dialysate for use in said dialyzer;
• and,
• dialyzer control means for controlling the inflow and outflow of body liquid and dialysate to and from said dialyzer in a reciprocating cyclic fashion while maintaining said dialysate within said dialysate side of said dialyzer at a non-elevated pressure throughout the entire cycle of said dialyzer, said dialyzer control means further for maintaining a positive pressure gradient from said body liquid side to said dialysate side throughout the reciprocating cycle of said dialyzer.