Pediatric Implantable Low-Shear Pulsatile Blood Pump with Physiologic Sensing and Control

项目总结/摘要 该项目的目标是开发高级生理控制，改善低级动态活塞控制， 并为儿科TORVAD TM开发血流动力学传感功能，这是一种独特的心室辅助系统 通过控制活塞在环形通道内的运动， 增压室小儿TORVAD适用于体表面积为0.6至1.5 m2的患者， 但是该设计可以按比例调整以适应各种各样的患者体型和需要。泵送中的低剪切 通过由流体动力轴承支撑的活塞的相对低的速度来管理血液 保持固定的活塞环间隙。主操作模式提供15 mL反脉冲喷射，但 该泵还可以异步操作以输送高达4L/min的完全心脏支持。该系统 与心脏相连，以保持主动脉瓣流量，并通过心脏瓣膜维持心输出量的自动调节。 Frank-Starling机制TORVAD的设计还可以确定差动泵 压力，无需额外的传感器。这种固有的感知能力可用于告知患者 药物和最佳泵支持。这些器械优势已在台架研究中得到证实 以及对成年TORVAD进行的急性和慢性动物实验，结果表明保留了 高分子量血管性血友病因子儿科TORVAD的设计旨在展示这些相同的 优点，因此具有减少出血、血栓形成和中风的潜力， 与其他小儿心室辅助装置的使用相关。第一阶段的具体目标是：（1）改善 动态活塞控制;（2）在泵驱动期间实施动态压力传感;以及（3）开发 全身血管阻力（SVR）估计。第二阶段的具体目标是：（1）实施生理 VAD流量控制;（2）制作急性和慢性动物实验装置;（3）进行四次急性 动物研究，以评估控制算法、压力信号感测和SVR估计;（4）进行六次 慢性动物研究，以评估儿科TORVAD和算法的长期可行性。

Project Summary / Abstract The goal of this project is to develop high-level physiological control, improve low-level dynamic piston control, and develop hemodynamic sensing capabilities for the pediatric TORVADTM, a unique ventricular assist system that delivers low-shear, synchronous, pulsatile flow, using controlled piston motion within a torus-shaped pumping chamber. The pediatric TORVAD is intended for patients with a body surface area from 0.6 to 1.5 m2, but the design can be scaled to adapt to a wide variety of patient sizes and needs. Low shear in the pumped blood is managed by the relatively low speed of the pistons which are supported by hydrodynamic bearings that maintain a fixed piston-torus gap. The primary operating mode delivers a 15 mL counterpulse ejection, but the pump can also operate asynchronously to deliver full cardiac support up to 4 L/min. The system synchronizes with the heart to preserve aortic valve flow and maintains autoregulation of cardiac output by the Frank-Starling mechanism. The design of the TORVAD also enables determination of differential pump pressure, without additional sensors. This inherent sensing capability can be used to inform patient medications and optimal pump support. These device advantages have been confirmed in benchtop studies and acute and chronic animal experiments with an adult TORVAD, and results have indicated preservation of high-molecular-weight von Willebrand Factor. The pediatric TORVAD has been designed to exhibit these same advantages, and thus has the potential to reduce bleeding, thrombus formation, and strokes that are associated with the use of other pediatric ventricular assist devices. Specific aims for Phase I are: (1) Improve the dynamic piston control; (2) Implement dynamic pressure sensing during pump actuation; and (3) Develop systemic vascular resistance (SVR) estimation. Specific aims for Phase II are: (1) Implement physiologic control of VAD flow; (2) Fabricate devices for acute and chronic animal experiments; (3) Perform four acute animal studies to assess control algorithms, pressure signal sensing, and SVR estimation; (4) Perform six chronic animal studies to assess long-term viability of the pediatric TORVAD and algorithms.