DEVELOPMENTAL OF VENTRICLE ASSIST DEVICE (VAD) ACTUATOR

这一第二阶段计划的目标是设计和开发一种创新的新型执行器，将FMT的“磁螺杆”和“磁弹簧”概念结合在一起，生产出一种针对脑室辅助装置(VAD)进行优化的高效、长寿命、紧凑的执行系统。已经在全人工心脏执行器中成功演示的磁螺杆作为植入式血泵的驱动器具有许多优点，即紧凑、减少磨损和疲劳，以及几乎无损地将旋转运动转换为平移驱动。磁弹簧的增加是专门针对VAD应用的。由于只有一个泵室，致动器的回程被用来在磁弹簧中储存能量，从而减小了致动器的物理尺寸和电机功率损失。MagSpring的概念在第一阶段得到了成功的验证，并产生了坚固耐用、高效的VAD。第二阶段的具体目标是：1)构建最终的、优化的VAD设计，集成磁螺杆/磁弹簧致动器和CCF生物血泵，2)开发VAD系统的原型控制器，3)进行VAD系统的体外耐力测试，以及4)在小牛身上进行VAD系统的体内测试。建议的商业应用：作为这项研究工作的结果，一种非常持久、可靠的VAD-直径108毫米，厚度58毫米，重量950克-将可用于永久植入物市场。根据医学研究所1991年发布的一份报告，这一市场估计每年包括30,000名候选人。一种足够安全、有效的VAD每年可能有多达20万例的市场。

The goal of this Phase II program is to design and develop an innovative, new actuator, combining FMT's concepts of the "magscrew" and "magspring" to produce a highly efficient, long-lived, compact actuating system optimized for ventricle assist devices (VADs). The magscrew, which has already been successfully demonstrated in a total artificial heart actuator, offers many advantages as a driver for implanted blood pumps; namely compactness, reduced wear and fatigue, and nearly lossless conversion of rotational motion to translational actuation. The addition of the magspring is specific to VAD applications. With only one pumping chamber, the return stroke of the actuator is used to store energy in a magspring and, thus, reduce the physical size and motor power losses of the actuator. The magspring concept was successfully validated in Phase I, and results in a rugged, efficient VAD. The Phase II specific aims are to: 1) construct a final, optimized VAD design integrating the magscrew/magspring actuator and a CCF biolized blood pump, 2) develop a prototype controller for the VAD system, 3) perform in vitro endurance tests of the VAD system; and 4) perform in vivo tests of the VAD system in calves. PROPOSED COMMERCIAL APPLICATIONS: As a consequence of this research effort, a very long-lived, reliable VAD - one with a 108-mm diameter, a 58-mm thickness, and a 950-g weight - will be available to the permanent implant market. This market has been estimated to include 30,000 candidates per year, according to a 1991 report published by the Institute of Medicine. A sufficiently safe, effective VAD could have a market as large as 200,000 cases per year.