报告题目：The Fluid Mechanics of the Human Fetal Heart, and the Development of Blood Pumps with Low Hemolysis Potential
报告人：Yap Choon Hwai博士
Yap Choon Hwai博士毕业于美国佐治亚理工学院（Georgia Institute of Technology） ，并于美国匹兹堡大学（University of Pittsburgh）医药系从事博士后研究 。目前作为助理教授就职于新加坡国立大学（National University of Singapore）生物医学工程系。研究方向为胎儿心血管系统的机理（the mechanics of prenatal cardiovascular system）以及低血栓血泵的研发（the fabrication of low-thrombosis blood pumps）。
(1) 面向人类胎儿心脏的图像化计算流体动力学 (The image-based computational fluid dynamics (CFD) of human fetal hearts)
The goal of the work is to understand the fluid mechanical force environment in human fetuses. We hypothesize that the normal mechanical force environments are necessary for proper cardiovascular development, and that abnormal mechanical forces environments causes congenital malformations. This hypothesis is corroborated by animal experiments and fetal surgery work from the literature. To test this hypothesis, we developed a technique for image-based CFD of human fetal hearts, where clinical 4D ultrasound images of 20 weeks old fetuses were obtained, and moving wall dynamic mesh CFD were performed to elucidate the flow patterns and forces in the ventricles. Results showed interesting ventricular vortex rings that interacted with one another and with the walls of the ventricle to elevate shear stresses. CFD of human fetal hearts with the Tetralogy of Fallot (TOF) malformations were also performed, and the wall shear stress and wall pressures of the right ventricle showed drastic alternations from the normal to TOF fetal hearts.
(2) 具有低溶血潜力的血泵研发 (Development of blood pumps with low hemolysis potential)
Current models of continuous blood pumps cause hemolysis in a substantial portion of recipients, and are associated with adverse outcomes: thrombosis and thrombo-embolism. Thrombo-embolism can be severe, such as in cases of stroke. Reducing hemolysis in blood pumps is thus an urgent task, since blood pumps are widely used in heart surgeries, ECMO support, hemodialysis and ventricular assistive devices. The first technique we attempted was the use of superhydrophobic surfaces in blood pumps, which could allow slip flow and reduction of blood stresses. The second technique was the use of a novel pumping mechanism that combines roller pumping and impedance pumping. Preliminary in vitro experiments of both techniques have shown promising results with hemolysis reduction.
Yap Choon Hwai博士毕业于美国佐治亚理工学院（Georgia Institute of Technology），并于美国匹兹堡大学（University of Pittsburgh）医药系从事博士后研究 。目前作为助理教授就职于新加坡国立大学（National University of Singapore）生物医学工程系 。他的其中一个研究方向是产前胎儿心血管系统的机理 ，以及异常血流机械力环境如何影响先天性心脏畸形 。他所在实验室是第一个基于临床超声影像进行人类胎儿的计算流体动力学模拟（CFD）的实验室 ，且开发了适用于高频超声的4D成像技术 ，用于小动物胚胎心脏的图像化CFD模拟 。他的另一个研究方向是研发低血栓血泵。他所在实验室正在探索新技术以减少血泵对血液的机械损伤 ，例如在连续流血泵中使用超疏水表面等。
Dr. Yap Choon Hwai graduated with PhD from Georgia Institute of Technology, and worked as a postdoctoral scholar in University of Pittsburgh School of Medicine. He is currently an Assistant Professor in the Department of Biomedical Engineering in the National University of Singapore. Part of his research focuses on the mechanics of prenatal cardiovascular system, and how abnormal blood flow mechanical force environment may be the cause of congenital heart malformations. His lab is the first to perform computational fluid dynamics (CFD) of human fetuses based on clinical ultrasound imaging, and developed suitable 4D imaging techniques with high-frequency ultrasound for image-based CFD of small animal embryonic hearts. Another part of his research is to fabricate low-thrombosis blood pumps. His lab is exploring novel technologies to reduce blood damage in pumps, such as the use of superhydrophobic surfaces in continuous blood pumps, and alternative methods of blood pumping.