A Real-Time Programmable Pulsatile Flow Pump for In-Vitro Cardiovascular Experimentation

Benchtop In-vitro experiments are valuable tools for investigating the cardiovascular system and testing medical devices. Accurate reproduction of physiologic flow waveforms at various anatomic locations is an important component of these experimental methods. This study discusses the design, construction and testing of a low-cost and fully programmable pulsatile flow pump capable of continuously producing unlimited cycles of physiologic waveforms. Two prototypes with different designs were tested. The first one consisted of a stepper motor – piston pump combination and tests showed that it failed to satisfy the design requirements. The second, highly successful prototype consists of a gear pump actuated by an AC servo-motor and a feedback algorithm enabling high accuracy for flow rates up to 300ml/s across a range of loading conditions. The iterative feedback algorithm uses flow error values in one iteration to modify motor control waveform for the next iteration to better match desired flow. Within 4-7 iterations of feedback, the pump replicated physiologic flow waveforms to high levels of accuracy (normalized RMS error less than 2%) under varying downstream impedances. This device is significantly more affordable (~10% of the cost) than current commercial options. Furthermore, the pump can be controlled via common scientific software packages and thus can be implemented in large automation frameworks

A Real-Time Programmable Pulsatile Flow Pump for In Vitro Cardiovascular Experimentation

Benchtop in vitro experiments are valuable tools for investigating the cardiovascular system and testing medical devices. Accurate reproduction of the physiologic flow waveforms at various anatomic locations is an important component of these experimental methods. This study discusses the design, construction, and testing of a low-cost and fully programmable pulsatile flow pump capable of continuously producing unlimited cycles of physiologic waveforms. It consists of a gear pump actuated by an AC servomotor and a feedback algorithm to achieve highly accurate reproduction of flow waveforms for flow rates up to 300 ml/s across a range of loading conditions. The iterative feedback algorithm uses the flow error values in one iteration to modify the motor control waveform for the next iteration to better match the desired flow. Within four to seven iterations of feedback, the pump replicated desired physiologic flow waveforms to within 2% normalized RMS error (for flow rates above 20 mL/s) under varying downstream impedances. This pump device is significantly more affordable (∼10% of the cost) than current commercial options. More importantly, the pump can be controlled via common scientific software and thus easily implemented into large automation frameworks