Factors affecting the pulsatile hydraulic power output of the Stockert roller pump

Abstract

A detailed assessment of the hydraulic power output of the Stockert roller pump was performed with the pump operating in its 'pulsatile' mode. Pressure and flow waveforms and the pulsatile power generated in a model of the human vascular bed were dependant upon the pump output, the pump control settings and the diameters of the arterial line, the pump insert and aortic cannula. The pulsatile power output was lower when a silicone rubber pump insert was used rather than a polyvinyl chloride insert. The incorporation of a Cobe CML flat-sheet membrane oxygenator into the arterial line reduced the pulsatile power to levels similar to those obtained with the pump operating in its 'continuous' mode. Incorporating a Sarns hollow fibre membrane oxygenator or a Pall extracorporeal blood filter had less effect and variations in perfusate viscosity or the length of the arterial line did not appear to have any effect. It seems probable that the experimental and clinical effects of 'pulsatile' flow during cardiopulmonary bypass with this pump will be highly dependant upon the operating conditions.