PRELIMINARY IN-VITRO EVALUATION OF THE NOVELCOR II VAD

Abstract

A mock circulatory loop was developed to assess the flow characteristics of NovelCor II, a newly designed Ventricular Assist Device (VAD). NovelCor II, developed by Dr. Domingo Liotta at the University of Moron, Argentina, is an implantable, pneumatically driven VAD designed primarily for myocardial recovery with atrial and abdominal aorta cannulations for the inflow and outflow conduits, respectively. The mock circulatory loop was designed to control changes on the preload and afterload pressures and monitor systemic pressure and pump output with the aid of pressure sensors and flow meters located at the inflow and outflow positions of the VAD. Data was acquired and analyzed using MAX and LabVIEW data acquisition system (National Instruments, TX). The NovelCor II was compared to a Thoratec paracorporeal VAD while both were operated with their respective pneumatic driver units. Pump outputs for the NovelCor II and Thoratec were determined by varying the following parameters: pump rate, preload and afterload pressures, driver eject pressure, and driver vacuum level. The pump rate was ranged from 30 to 120 bpm in intervals of 10 bpm; the preload was varied from 4 to 19 mmHg and the afterload from 80 to 120 mmHg; the eject pressure was set at 180, 200 or 220 mmHg and the vacuum level was set at -20 or 0 mmHg. Preliminary results showed that at variable preload pressures, the highest pump output was achieved at pump rates of 55–60 bpm for both VADs, but in the case of NovelCor II the pump output decreased faster at higher pump rates than with the Thoratec.