Development of a Pediatric Ventricular Assist Device

从早期开始，机械循环支持的使用在成人人群中逐渐增加， 心切开术后支持，移植桥支持，充血性心力衰竭的目的地治疗。移植前生存率、移植后生存率和相对于最佳药物治疗的目标治疗应用中的生存率已证明该技术在成人心力衰竭患者中的成功。然而，机械循环支持在儿科人群中的应用受到限制。据估计，需要支持的儿科患者人数远远少于成年人。儿科循环支持设备的潜在市场随后较小。此外，由于随着泵尺寸减小，流体粘性效应的重要性增加，小型血泵的设计具有挑战性，这可能导致血栓形成。 我们提出了一个脉动血泵的成功的成人大小的皮尔斯-Donachy心室辅助装置（VAD）的设计的基础上的发展。该泵设计已作为Thoratec V AD用于全球2000多名患者。这种方法在儿科应用中是有利的，因为该系统提供脉动流，相对不形成血栓，耐用，并且可以用于单心室或双心室支持。将开发两种儿科泵尺寸：婴儿10 ml每搏输出量泵和儿童25 ml每搏输出量泵。成人胰岛素泵的每搏输出量为65 ml。宾夕法尼亚州立大学先前的10 ml设计工作包括一系列30只动物研究，以及使用粒子图像测速仪（PN）和激光多普勒测速仪（LDV）对泵内流场进行的体外测量。 研制了一种新型气动便携式驱动器。该驱动器基于宾夕法尼亚州立大学为电动植入式血泵开发的致动器技术。驱动器设计在此应用中是独特的，因为它能够控制所施加的压力波形的形状，并且具有优异的耐用性、便携性和低噪声的潜力。 宾夕法尼亚州立大学在循环支持系统的设计、开发、临床使用和技术转让方面获得了重要的专业知识。除了Pierce-Donachy气动VAD之外，宾夕法尼亚州立大学还开发了一种名为Arrow Lionheart的完全植入式VAD，目前正在进行临床试验。宾夕法尼亚州立大学全人工心脏（TAH）是在NHLBI合同支持下设计的，目前正在进一步开发中。这种多学科的专业知识，沿着在生物材料，表面分析，流场成像和电子学的不断改进，将被应用于开发一个临床准备儿科辅助系统。

The use of mechanical circulatory support has grown in the adult population from early postcardiotomy support, to bridge-to-transplant support, to destination therapy for congestive heart failure. Survival to transplant, survival post-transplant, and survival in destination therapy applications relative to optimum medical therapy, have demonstrated the success of this technology in adult heart failure patients. However, application of mechanical circulatory support in the pediatric population has been limited. It is estimated that the number of pediatric patients requiring support is much smaller than the adult population. The potential market for pediatric circulatory support devices is subsequently smaller. In addition, the design of small blood pumps is challenging due to the increasing importance of fluid viscous effects as pump dimensions are reduced, which may lead to thrombus formation. We propose the development of a pulsatile blood pump based on the design of the successful adult-sized Pierce-Donachy ventricular assist device (VAD). This pump design has been used in over 2000 patients worldwide as the Thoratec V AD. This approach is advantageous in pediatric applications because the system provides pulsatile flow, is relatively non-thrombogenic, is durable, and may be used for uni-ventricular or bi-ventricular support. Two pediatric pump sizes will be developed; a 10 ml stroke volume pump for infants, and a 25 ml stroke volume pump for children. The adult pump has a 65 ml stroke volume. Previous work at Penn State with a 10 ml design included a series of 30 animal studies and in vitro measurements of the flow field in the pump using Particle Image Velocimetry (PN) and Laser Doppler Velocimetry (LDV). A novel pneumatic portable driver will be developed. The driver is based on actuator technology developed by Penn State for electrically-powered implantable blood pumps. The driver design is unique in this application due to its ability to control the shape of the applied pressure waveforms, and the potential for excellent durability, portability, and low noise. Penn State has gained significant expertise in the design, development, clinical use, and technology transfer of circulatory support systems. In addition to the Pierce-Donachy pneumatic VAD, the fully implantable VAD known as the Arrow Lionheart was developed at Penn State and is currently in clinical trials. The Penn State Total Artificial Heart (TAH) was designed under NHLBI contract support and is currently under further development. This multidisciplinary expertise, along with the continuing improvements in biomaterials, surface analysis, flow field imaging, and electronics, will be applied to developing a clinically-ready pediatric assist system.