Patent ID: 7842003

Claim:
A method of creating a continuous pulsatile flow of fluid into a biological destination, comprising: providing a piston pump having at least one pump chamber, wherein said pump chamber holds a disposable flexible cassette formed from two sheets of flexible material bonded together along a selected bond area to form at least one fluid-containing chamber and particularized open flow paths; providing a spline piston adjacent to said pump chamber in the piston pump; wherein advancement of the piston causes fluid to flow from said flexible cassette in the pump chamber to the biological destination, wherein the flow rate of the fluid leaving the pumping chamber is related quadratically to the velocity of the piston and wherein said flow rate is independent of fluid pressure; and advancing the piston according to a cyclical, time-varying velocity profile that emulates a human heart, wherein advancement of the piston is divided into multiple periods, each period including a first partial cycle at a predefined, controlled lower velocity and a second partial cycle at a predefined, controlled upper velocity, and wherein the predefined upper and lower controlled velocities of the piston correspond to an upper and a lower output flow rate, respectively.