US 7,842,003 B2 · Pulsatile fluid delivery system

Abstract

A system for delivering blood, cardioplegia solution, and other medications or fluids in a pulsatile flow pattern to a patient during cardiopulmonary bypass is disclosed. In a preferred embodiment, a pumping apparatus having at least one chamber is utilized in which a pumping action is achieved by compressing one of the chambers with a piston mechanism, while allowing the other chamber to fill with fluid via retracting its respective piston. The instantaneous flow rate of either of the chambers is determined by the speed of the piston. In a preferred embodiment, a pulsatile flow of fluid is achieved by cyclically alternating the velocity of the piston between two different speeds. A desired average flow rate and/or delivery pressure and/or constant pulse pressure is maintained by adjusting the alternating velocities at the desired frequency and duty cycle. The calculations necessary to obtain a desired average flow rate are performed by a microprocessor, which also controls the movement of the pistons.

Claims38

Dependent claims

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.

2 more elements

Dependencies are inferred from the claim text.

Pulsatile fluid delivery system

Life of this patent

Pulsatile fluid delivery system

Life of this patent

Abstract

Claims38