Hemolysis Test Of Magnetic And Hydrodynamic Levitation Blood Pump

ObjectiveAfter being planted into the body for circulation assist, magnetic and hydrodynamic levitation blood pump can cause damage to blood cells.This project aimed to study the hemolysis performance of the blood pump through both in vitro circulation simulation experiment and short-term animal experiment two ways.MethodsIn vitro circulation simulation experiment.At first, established the vitro circulation loop system.Then connected the blood pump to the vitro circulation loop system, made sure the order of connection was right. Collected the fresh sheep blood just before the experiment as the circulating medium. Adjusted speed of blood pump to2900rpm,set its preload and afterload at15mmHg and100mmHg, detected plasma free hemoglobin(FHB) and hematokrit(Hct) in every hours, then calculated the normalized index of hemolysis (NIH).In short-term animal experiment,we chooseed three grown and heathy sheep of about60kilograms weight.Under general anesthesia, respirator assisted ventilation and without cardiopulmonary bypass, a left thora-cotomy was performed at the5th intercostal space to provide access and exposure of left ventricular apex, and descending thoracic aorta.Then planted the entrance cannula of blood bump into left ventricular apex, the outflow cannula was connected to descending thoracic aorta.The blood operated for more than4days at speed of2800rpm. Animals were anticoagulated with heparin. Venous blood samples (5mL) were drawn to measure blood routine, serum chemistries and plasma free hemoglobin for every24h.ResultsIn vitro circulation simulation test, the blood pump operated smoothly and stably without been stucked and shut down, the NIH was (0.0038±0.0008) g/100L.In short-term animal experiment,sheeps all detached from the respirator and survived for more than4days.During the experiment none of the sheeps suffered from organ failure. After the surgery, plasma free hemoglobin of the animals was temporarily increasing.But then it gradually came down to normal level in a few days.Conclusion: The magnetic and hydrodynamic levitation blood pump has good hemolytic performance and stable mechanical property that can meet the need for animal experiments.