NEW METHODOLOGIES FOR THE DESIGN OF SMALL BLOOD PUMPS

小型血泵设计的新方法

• 批准号: 6389913
• 负责人: GERSON ROSENBERG
• 金额: $ 54.81万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-15 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6389913
• 关键词: antithrombogenic surface; biomedical equipment development; blood flow measurement; circulatory assist; computer simulation; cow; electronic pacemaker; fluorescence microscopy; hematology; hemolysis; heterodyning; histology; implant; medical implant science; miniature biomedical equipment; ultrasound blood flow measurement

The long-term 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 adult patients. We propose to study the underlying principles of pump size reduction through three specific aims: First, we will compare in vitro measurements of the flow field with in vivo measures of thrombogenesis and hemolysis. Specifically, we will use Laser Doppler Anemometry and Particle Image Velocimetry to measure fluid velocity and shear rate, with a high degree of spatial and temporal resolution, in pump chambers designed according to various scaling parameters. Classical dimensionless analysis will serve as guidance in scaling to achieve fluid dynamic similitude, and to generalize these measurements for predictive purposes. The significance of these findings will be assessed through in vivo studies in calves using completely implanted total artificial hearts, using the same pump chambers under similar fluid dynamic conditions. Thrombogenesis will be assessed through hematology studies and explant analysis. Platelet and fibrin adhesion will be quantified using histological examination and epi-fluorescence microscopy, using fluorescently labeled platelets and fibrinogen. Novel rapid manufacturing methods will be used to fabricate the variety of pumping chambers required for these experiments. Secondly, we will develop 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 thereby optimize the major subsystems to minimize power consumption. Results will be validated on a mock circulatory loop. Thirdly, we will study the effects of reduced pump chamber size and pump shape parameters on biomaterial stresses using finite element analysis. Predicted strains will be validated using staticly pressurized pump chambers. We expect that this research will be broadly applicable to pulsatile blood pump design, especially by improving our understanding of the relationships between 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.

这项研究的长期目的是使较小的成年患者可用的脉动心脏替代系统。这是一个非微不足道的问题，因为脉冲血泵的大小减少会影响（1）泵的流体动力学，（2）泵和执行器的能量，以及（3）血接触材料所经历的压力。 因此，我们认为此处描述的研究对成年患者的全部范围的人造心脏和脉冲心室辅助设备的可用性至关重要。 我们建议通过三个特定目的研究泵尺寸减小的基本原理：首先，我们将比较流场的体外测量与体内血栓形成和溶血的测量。具体而言，在根据各种尺度参数设计的泵室中，我们将使用激光多普勒动态测定法和粒子图像速度法以高度的空间和时间分辨率测量流体速度和剪切速率。经典的无量纲分析将作为扩展以实现流体动态相似的指导，并以预测目的概括这些测量值。 这些发现的重要性将通过在相似的流体动态条件下使用相同的泵室进行完全植入的人造心脏的犊牛进行体内研究来评估。血栓形成将通过血液学研究和外植体分析评估。血小板和纤维蛋白的粘附将使用组织学检查和荧光显微镜进行定量，并使用荧光标记的血小板和纤维蛋白原进行定量。 新型快速制造方法将用于制造这些实验所需的泵室。其次，我们将利用能源转换器，血泵，循环，控制器和能量传输系统的计算机模拟来建立有关系统能量性能的关系。因此，我们将优化主要子系统以最大程度地减少功耗。 结果将在模拟循环循环中进行验证。第三，我们将研究使用有限元分析的泵室大小和泵形参数对生物材料应力的影响。预测菌株将使用静态加压泵室进行验证。我们预计这项研究将广泛适用于脉动血泵设计，尤其是通过提高我们对复杂，时变流场中流体动力学与血栓形成之间关系的理解。 这项工作需要在手术，工程，流体力学和血液学方面做出多学科的工作，并具有有效生产血泵系统并进行必要的体外和体内研究的手段。