Development of a Pediatric Ventricular Assist Device

在成年人群中，机械循环支持的使用从早期就开始增长。 心脏切开术后支持，桥接移植支持，充血性心力衰竭的目的地治疗。与最佳药物治疗相比，移植后存活、移植后存活以及目的地治疗应用中的存活都证明了这项技术在成年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一直受到限制。据估计，需要支助的儿科病人的数量远远少于成年人口。因此，儿科循环支持设备的潜在市场较小。此外，小型血泵的设计具有挑战性，因为随着泵尺寸的减小，流体粘性效应的重要性越来越大，这可能会导致血栓的形成。 我们提出了一种基于成功的成人大小的皮尔斯-多纳奇心室辅助装置(VAD)的设计的脉动血泵的开发。这种泵的设计已经在全球超过2000名患者中使用，被称为Thoratec V AD。这种方法在儿科应用中是有利的，因为该系统提供脉动血流，相对不会导致血栓，是耐用的，并且可以用于单室或双室支持。将开发两种型号的儿科泵：用于婴儿的10毫升冲程量泵和用于儿童的25毫升冲程量泵。成人泵有65毫升的冲量量。宾夕法尼亚州立大学之前的10毫升设计工作包括一系列30项动物研究，并使用粒子图像测速仪(PN)和激光多普勒测速仪(LDV)对泵内的流场进行了体外测量。 将开发一种新型的气动便携式驱动器。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执行器技术。驱动器设计在该应用中是独一无二的，因为它能够控制所施加的压力波形的形状，并具有出色的耐用性、便携性和低噪音的潜力。 宾夕法尼亚州立大学在循环支持系统的设计、开发、临床应用和技术转让方面获得了重要的专业知识。除了皮尔斯-多纳奇气动VAD外，宾夕法尼亚州立大学还开发了名为Arrow LionHeart的完全可植入的VAD，目前正在进行临床试验。宾夕法尼亚州立大学人工心脏(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，以及在生物材料、表面分析、流场成像和电子学方面的持续改进，将被应用于开发临床就绪的儿科辅助系统。

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.