Active Pneumatic Pulsation Damper for Peristaltic Pump Flow Loops

A novel concept of an active pulsation damper is described that cancels parasitic flow pulsatility of peristaltic pumps and is able to inject desired pulsatility signatures such as physiological heart beat. Peristaltic pumps avoid contact between the moving parts of a pump and the operating fluid. They are used for clean or sterile fluids as well as for highly aggressive fluids, whenever it is important to isolate the fluid from the environment. The background application for the proposed active pulsation damper is the simulation of hemodynamic flow. The paper presents a novel pulse damper concept that allows the use of roller or peristaltic pumps as primary pumps for hemodynamic flow loops. The problem with peristaltic pumps is that they exhibit a high parasitic pulsatility that needs to be canceled before a desired pulsatility can be injected. The active pulsation damper does this and is also used to superpose a desired flow pattern that resembles measured heart flow rate profiles. The nonlinear dynamic equations of a test system with active pulsation dampers are established and linearized to allow a first analysis of the achievable bandwidth. Simulation results of the closed loop system are presented based on the non-linear equations.