This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the in...This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.展开更多
This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient cond...This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.展开更多
Background: Tongxin left ventricular assist device(LVAD), an implantable magnetic suspending VAD developed in China Heart Biomedical Incorporation aiming for clinical use, weighs about 350 g and can deliver 6 L/min fo...Background: Tongxin left ventricular assist device(LVAD), an implantable magnetic suspending VAD developed in China Heart Biomedical Incorporation aiming for clinical use, weighs about 350 g and can deliver 6 L/min for pressures of 145 mmHg at 2500 rpm. Objective: This study aims to investigate the implantation possibility, hemolysis and hemocompatibility of the LVAD before clinic use. Methods: The tests of implantation possibility, hemolysis and hemocompatibility to the LVAD were completed by fitting study, hemolysis test and in vivo experiments respectively. Meanwhile the hemolysis was evaluated by the amount of free hemoglobin in plasma and studied using the normalized index of hemolysis(NIH). Results: The fitting study showed that the blood pump could be implanted in the sheep heart chambers without squeezing the surrounding organs by comparing the preoperative and the postoperative chest X-ray. The NIH value of Tongxin LVAD was(0.00750±0017) g/100 L in vitro hemolysis test. Two sheep in vivo experiments showed the hemolysis in vivo was below 7.5 mg/dL. Hematologic and biochemical test results were within normal limits during the study period. There were no significant complications. Postmortem examination of the explanted organs revealed no evidence of microemboli, ischemia or infarction. The pump's inflow and outflow conduits were free of thrombus. Conclusion:These results indicated that the implantable magnetic suspending LVAD showed exceptional implantation possibility, hemolysis and hemocompatibility, which are crucial to the clinical success of this implantable LVAD.展开更多
基金supported by the National High Technology Research and Development program of China (863 Program, Grant No. 2007AA02Z439)The Program for Outstanding Medical Academic Leader of Shanghai
文摘This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.
文摘This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.
文摘目的探讨植入型心室辅助装置稳定性、主体血泵溶血性能及可植入性。方法首先,辅助装置在常温下连续驱动蒸馏水30 d,观察血泵转速、驱动电流等变化情况,测试其稳定性。同时,在流量5 L/min左右,出入口压差为100 mmHg情况下,心室辅助装置通过体外模拟循环实验台驱动羊血完成溶血性能测试,最后计算出血泵标准溶血指数(normal index of hematolysis,NIH)。最后,将心室辅助装置模拟主体血泵植入实验动物体内,对比术前及术后胸片,检验植入血泵对实验动物心室及周围器官的影响,验证其植入性能。结果辅助装置常温下连续驱动蒸馏水30 d,无卡泵和渗漏现象发生;血泵溶血性能良好,NIH值为(0.008±0.002)g/100 L;血泵可以很容易的植入心腔,植入血泵对实验动物心脏及周围器官无挤压变形。结论实验结果证明植入型心室辅助装置具有良好的稳定性、溶血性能以及可植入性。
文摘Background: Tongxin left ventricular assist device(LVAD), an implantable magnetic suspending VAD developed in China Heart Biomedical Incorporation aiming for clinical use, weighs about 350 g and can deliver 6 L/min for pressures of 145 mmHg at 2500 rpm. Objective: This study aims to investigate the implantation possibility, hemolysis and hemocompatibility of the LVAD before clinic use. Methods: The tests of implantation possibility, hemolysis and hemocompatibility to the LVAD were completed by fitting study, hemolysis test and in vivo experiments respectively. Meanwhile the hemolysis was evaluated by the amount of free hemoglobin in plasma and studied using the normalized index of hemolysis(NIH). Results: The fitting study showed that the blood pump could be implanted in the sheep heart chambers without squeezing the surrounding organs by comparing the preoperative and the postoperative chest X-ray. The NIH value of Tongxin LVAD was(0.00750±0017) g/100 L in vitro hemolysis test. Two sheep in vivo experiments showed the hemolysis in vivo was below 7.5 mg/dL. Hematologic and biochemical test results were within normal limits during the study period. There were no significant complications. Postmortem examination of the explanted organs revealed no evidence of microemboli, ischemia or infarction. The pump's inflow and outflow conduits were free of thrombus. Conclusion:These results indicated that the implantable magnetic suspending LVAD showed exceptional implantation possibility, hemolysis and hemocompatibility, which are crucial to the clinical success of this implantable LVAD.
