NEW METHODOLOGIES FOR THE DESIGN OF SMALL BLOOD PUMPS

描述(由申请人提供)：这项研究的目标是使脉搏心脏替代系统可用于较小的成年患者。这不是一件微不足道的事情，因为脉动血泵尺寸的减小会影响(1)泵的流体动力学，(2)泵和执行器的能量，以及(3)血液接触材料所承受的压力。因此，我们认为，这里所描述的研究对于为所有患者提供人工心脏和搏动性心脏辅助设备至关重要。我们建议通过三个具体目标研究泵尺寸缩小的基本原理：第一，利用CFD建模、实验流体动力学技术、体外测试和体内研究的综合方法，利用物理设计约束显著改进缩小尺寸的血泵和能量转换器设计。这些建模和体外研究将用于预测系统性能。这些发现的意义将通过对小牛的活体研究来评估。血栓形成将通过血液学研究、血小板活化研究和外植体分析来评估。血小板和纤维蛋白的粘附性将通过移植后大体检查、组织学检查和多尺度表面分析来定量。其次，我们利用对能量转换器、血泵、循环、控制器和能量传输系统的计算机模拟，建立了控制系统能量性能的关系。我们将量身定做执行器运动的控制，以改进流体力学。这些研究的结果也将在体外和体内进行评估。第三，我们将改进和利用预测和最小化生物材料中的应力所需的改进的有限元模型，以便缩小尺寸的设备的耐用性不会因泵的结垢而受到不利影响。我们希望这项研究将广泛应用于脉动血泵的设计，特别是通过提高我们对复杂、时变流场中表面效应、流体动力学和血栓形成之间关系的理解。这项工作需要外科、工程学、流体力学和血液学等多学科的努力，以及有效制造血泵系统和进行必要的体外和体内研究的手段。 公共卫生相关性：本研究结合计算流体力学、实验流体动力学、系统建模、有限元分析、体外和体内技术，开发了一种设计小型血泵的综合方法。

DESCRIPTION (provided by applicant): The objective of this research is to make pulsatile heart replacement systems available to smaller adult patients. This is a non-trivial matter, because reduction in the size of a pulsatile blood pump affects (1) the fluid dynamics of the pump, (2) the energetics of the pump and actuator, and (3) the stresses experienced by the blood contacting materials. Thus, we consider studies such as those described here to be critical to the availability of artificial hearts and pulsatile ventricular assist devices for the full spectrum of patients. We propose to study the underlying principles of pump size reduction through three specific aims: FIRST, Utilize an integrated method of CFD modeling, experimental fluid dynamics techniques, in vitro testing and in vivo studies to significantly improve reduced size blood pumps and energy converter designs utilizing physical design constraints. These modeling and in-vitro studies will be used to predict system performance. The significance of these findings will be assessed through in vivo studies in calves. Thrombogenesis will be assessed through hematology studies, platelet activation studies, and explant analysis. Platelet and fibrin adhesion will be quantified by post explant gross exam, histological examination and multi-scale surface analysis. SECONDLY, we have developed relationships governing energetic performance of the system, utilizing a computer simulation of the energy converter, blood pump, circulation, controller, and energy transmission system. We will tailor control of actuator movement to improve fluid mechanics. The results of these studies will also be evaluated in-vitro and in-vivo. THIRDLY, we will refine and utilize improved FEA models necessary for predicting and minimizing stresses in biomaterials, so that durability of reduced-size devices is not adversely affected by pump scaling. We expect that this research will be broadly applicable to pulsatile blood pump design, especially by improving our understanding of the relationships between surface effects, fluid dynamics, and thrombogenesis in a complex, time-varying flow field. This work requires a multi-disciplinary effort in surgery, engineering, fluid mechanics, and hematology, with the means to efficiently manufacture blood pump systems and carry out the necessary in vitro and in vivo studies. PUBLIC HEALTH RELEVANCE: This research combines computational fluid dynamics, experimental fluid dynamics, systems modeling, finite element analysis, in vitro and in vivo techniques to develop a comprehensive method for the design of small blood pumps.