Corwave LVAD Development Update

Abstract

Purpose The Corwave Neptune LVAD is being developed to employ gentle oscillation of a membrane to propel blood, based on the wave motion of swimming fish. The pump output can be readily tuned by adjusting membrane oscillation frequency and magnitude. The purpose of this project was increase the hydraulic efficiency, implement a physiologic pulsatility control algorithm, and confirm performance in animal implants. Methods The fluid path of the pump was simulated by Fluid-Structure-Interaction (FSI) computational fluid dynamic analysis in COMSOL. Membrane size, oscillation frequency, oscillation magnitude, and the blood flow path were modeled and refined to improve hydraulic performance and eliminate areas of flow stagnation. Pumps were then tested in blood analogs and blood in mock circulation loops and in vitro hemolysis testing. Non-hermetic pumps were implanted in a total of 25 sheep for acute and chronic implants. Results Design simulations and individual component testing resulted in a pump which can generate 6+ LPM of blood flow against physiologic pressures with maximum shear rates orders of magnitude lower that those of rotary blood pumps. Mock loop testing demonstrated the pumps have “flat” HQ (pressure vs. flow) curves. Three control methods were developed: fixed, asynchronous pulsatile, and synchronous pulsatile. Pulsatile modes generated dP/dt>400 mmHg/sec using sensorless detection of native ventricle systole. Animal implants demonstrated low hemolysis and an absence of renal infarcts, but were limited to about a week in duration due to the non-hermetic sealing of the pumps. Conclusion Application of robust computational simulation and bench top testing have produced a unique new kind of VAD, offering the flow capacity and reliability of rotary pumps, but adding physiologically relevant pulsatility without excessive shear rates. Future efforts will implement full hermeticity to extend animal study durations and confirm von Willebrand Factor compatibility. The Corwave Neptune LVAD is being developed to employ gentle oscillation of a membrane to propel blood, based on the wave motion of swimming fish. The pump output can be readily tuned by adjusting membrane oscillation frequency and magnitude. The purpose of this project was increase the hydraulic efficiency, implement a physiologic pulsatility control algorithm, and confirm performance in animal implants. The fluid path of the pump was simulated by Fluid-Structure-Interaction (FSI) computational fluid dynamic analysis in COMSOL. Membrane size, oscillation frequency, oscillation magnitude, and the blood flow path were modeled and refined to improve hydraulic performance and eliminate areas of flow stagnation. Pumps were then tested in blood analogs and blood in mock circulation loops and in vitro hemolysis testing. Non-hermetic pumps were implanted in a total of 25 sheep for acute and chronic implants. Design simulations and individual component testing resulted in a pump which can generate 6+ LPM of blood flow against physiologic pressures with maximum shear rates orders of magnitude lower that those of rotary blood pumps. Mock loop testing demonstrated the pumps have “flat” HQ (pressure vs. flow) curves. Three control methods were developed: fixed, asynchronous pulsatile, and synchronous pulsatile. Pulsatile modes generated dP/dt>400 mmHg/sec using sensorless detection of native ventricle systole. Animal implants demonstrated low hemolysis and an absence of renal infarcts, but were limited to about a week in duration due to the non-hermetic sealing of the pumps. Application of robust computational simulation and bench top testing have produced a unique new kind of VAD, offering the flow capacity and reliability of rotary pumps, but adding physiologically relevant pulsatility without excessive shear rates. Future efforts will implement full hermeticity to extend animal study durations and confirm von Willebrand Factor compatibility.