Circulation System Modelling with National Implantable Ventricular Assist Device (NIVAD): Hydrodynamic Characters, Hemolysis Test in Vitro and Animal Experiments

This study is to detect the flow field characters of NIVAD and the hemolysis test in vitro and to evaluate the hemodynamic performance and the influence on calves. The flow field characters of NIVAD were calculated by CFD. In hemolysis test in vitro, controlled flow of NIVAD 5 L/min and the outflow tract pressure 100 mmHg, the plasma free hemoglobin (FHB) content and the hematocrit (HCT) were measured at 0, 0.5, 1,. 4 hours. Then NIH (Normal Index of Hemolysis) of NIVAD was calculated. In vivo experiments, NIVAD was implanted in 8 calves. Physiological index and biochemical data of serum were taken during the experiments. The nephograms show the speed and pressure change of NIVAD flow field by CFD. The hemolysis, which was evaluated by NIH was 0.065+/-0.014mg/L in vitro, by FHB was below 10 mg/dl in vivo. There was no obvious thrombus and adverse events on the animals and pumps. Biochemical data of serum evaluation showed that implantation of NIVAD in calves did not impair end organ function. Gross and microscopic sections of kidney, liver, and lung revealed no evidence of microemboli, edma or infracts. The index of NIVAD satisfy the request of clinic use. The results of experiments in vitro and in vivo lay foundations for clinic use in future.