New Magnetically Suspended LEV-VAD

描述（由申请人提供）：本项目的主要目标和目的是开发和确认LEV-VAD，并提供足够的结果和文件，以便向FDA提交试验用器械豁免申请，以获得临床试验批准。我们建议开始测试和确认我们目前设计和制造的器械，通过一系列精心计划和执行的步骤进行体外表征。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和这些功能以及性能模拟研究。然后，LEV-VAD将具有性能曲线，并在模拟循环中进行良好表征，其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操作泵。在获得初步验证结果后，将该器械植入一系列健康小牛体内长达6小时，以确保解剖结构匹配并评估完全内固定小牛的功能。在随后的一系列长达两个月的装有仪器的小牛中，心血管系统将受到药物的干扰，并减少和/或增加体积和快速心率。在内固定和非内固定实验中，植入持续时间更长。在设计和特性良好的原型II得到验证后，设计将被冻结。其中10台设备将置于FDA批准的测试电路和测试方案上一年，以证明泵及其控制器的可靠性。一个主要的努力将是开发一个响应的生理控制器，利用第一次监测叶轮上的轴向力（电力电子轴承），结合电力输送到电机。初步研究表明，悬浮轴承和电机功率的现成可用功率可以用于非常灵敏的控制器。如果不能用这两个基本参数开发鲁棒响应控制器，则心率和/或来自跨音速流量计的信号将被并入算法中。有大量的充血性心力衰竭患者不太可能接受供体心脏。现有VAD的机械故障和血栓栓塞发生率较高。我们的设计目标是为接受者提供一种可以延长20年寿命的设备。我们有很高的信心，在完成这些拟议研究时，我们将了解LEV-VAD作为目标治疗器械的应用和局限性。

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.