Design and Validation of an Open Loop Controlled Positive-Displacement Pump for Vascular Flow Modelling

Abstract

Realistic vascular flow-rates are highly patient dependent. There is a need, when evaluating vascular medical devices, to study variable physiological flow-rates corresponding to specific patients. This study presents an experimental analysis of a positive-displacement piston pump designed for generating patient-specific vascular flow-rate wave-forms. Open loop control is used to drive a positive-displacement piston pump according to user-input physiological wave-forms. Transient and frequency analyses are performed for simple and complex inputs. Theoretical analysis of the system shows that it may be modelled as a linear first order system and the response of the system for various inputs shows that the real system approximates a linear first order response, however, higher order effects are noted. These higher order effects do not have any particular detrimental effect on the generation of physiologically realistic flow-rate waveforms.