New Magnetically Suspended LEV-VAD

描述(由申请人提供)：本项目的主要目标和目标是开发和验证LEV-VAD，并提供足够的结果和文件，以便向FDA提交研究设备豁免申请，以获得临床试验的批准。我们建议通过一系列精心计划和执行的步骤，通过体外表征开始测试和验证我们目前设计和制造的设备。这些步骤包括利用选定的几个计算机程序来优化设计组件以及这些功能和性能模拟研究。LEV-VAD将具有性能曲线，并在模拟循环中具有良好的特性，在模拟循环中，电机和电磁轴承控制器将进行优化，以在体内预期范围内运行泵。在初步验证结果后，该装置将被植入一系列健康小牛体内长达六个小时，以确保解剖匹配并评估完全装有器械的小牛的功能。在随后的一系列可存活到两个月的仪表化小牛中，心血管系统将受到药物的干扰，并移除和/或增加容量和快速心率。在仪器化和非仪器化的实验中，植入的时间都会更长。在设计和性能良好的原型II得到验证后，设计将被冻结。其中10个设备将放置在FDA批准的测试电路和测试方案上，为期一年，以证明泵及其控制器的可靠性。主要的工作将是开发一种反应灵敏的生理控制器，首先利用监测叶轮上的轴向力(电子轴承的功率)，结合提供给电机的功率。初步研究表明，可随时获得的悬浮轴承功率和电机功率可用于非常灵敏的控制器。如果用这两个基本参数不能开发出稳健的响应控制器，则心率和/或来自跨音速流量计的信号将被纳入算法中。有大量充血性心力衰竭患者不太可能接受捐献心脏。现有的VAD具有较高的机械故障和血栓栓塞率。我们的设计目标是为接受者提供目的地治疗，这种设备可以延长20年的寿命。我们有很高的信心，在完成这些拟议的研究后，我们将知道LEV-VAD作为目的地治疗设备的应用和局限性。

DESCRIPTION (provided by applicant): The primary goal and objective of this project is to develop and validate the LEV-VAD with sufficient results and documentation to submit an Investigational Device Exemption application to the FDA to obtain approval for clinical trials. We propose to begin testing and validating our present designed and manufactured device through in vitro characterization in a series of well planned and executed steps. These steps include utilizing several computer programs selected to optimize the design components and these functions and performance simulation studies. The LEV-VAD will then have performance curves and well characterized in mock circulations where both the motor and electromagnetic bearing controllers will be optimized to operate the pump within the anticipated ranges in vivo. After preliminary results of verification the device will be implanted into a series of healthy calves for up to six hours to assure the anatomic fit and assess function in the in fully instrumented calves. In a later series of instrumented calves living up to two months, the cardiovascular system will be perturbed with drugs and removing and/or adding volumes and rapid heart rate. Implants will be done for longer durations in both instrumented and noninstrumented experiments. After the design and well-characterized prototype II are verified, the design will be frozen. Ten of these devices will be placed on an FDA-approved test circuit and test protocols for one year to demonstrate reliability of the pump and its controller. A major effort will be to develop a responsive physiologic controller utilizing first monitoring the axial forces on the impeller (power to the electronic bearings), in combination with the power delivered to the motor. Preliminary studies demonstrated that the readily available power for the levitation bearing and motor power can be used for a very sensitive controller. If a robust responsive controller cannot be developed with these two basic parameters the heart rate and/or the signal from the transonic flow meter will be incorporated into the algorithm. There are a large number of congestive heart failure patients unlikely to receive a donor heart. The existing VADs have a high rate of mechanical failure and thromboemboli. Our design targets destination therapy for recipients with a device that could provide a 20-year life extension. We have a high level of confidence that at the completion of these proposed studies we will know the application and limitations of the LEV-VAD as a destination therapy device.