Feasibility Study of Advanced Circulatory Support Devices that Enable Recovery and Optimal Therapy of Heart Failure in Pediatric and Adult Patients

这项研究致力于设计和开发先进的循环支持装置，旨在为儿童和成人提供至少一个月的中短期抗凝治疗，使其能够完全恢复，或用于连接到更高级的治疗方式，如植入性装置或心脏移植。为了实现这一目标，利用紧凑型磁轴承设计了一种用于成人应用的一次性磁悬浮(MAG-LEV)离心式血泵，其初始体积为23ml。将X、Y两自由度主动磁悬浮轴承与永磁体相结合，被动恢复叶轮转子在轴向和倾斜轴上的位置，实现了紧凑型磁悬浮轴承。叶轮的旋转是通过安装在电机轴上的内驱动磁体和成型在叶轮转子内部的从动磁体之间的径向磁耦合来实现的。泵的性能分析…进一步分析表明，在4500转/分的转速下，泵的最大扬程压力为800 mm Hg，流量为5L/min。溶血研究表明，对血细胞成分的机械损伤大约是临床使用的BioPump BPX-80的一半。到目前为止，利用小牛进行的活体研究表明，该泵系统可以满足成人患者一周的循环支持要求，而抗凝治疗的要求最低。至于儿科应用，已为3-10公斤的新生儿和婴儿设计了一种微型离心式血泵TinyPump，其最佳容量为5ml，低流量控制能力稳定在0.2L/min。叶轮转子直径为30 mm，有六个直叶片，因此泵的外径为50 mm。泵头是一次性的，很容易从可重复使用的电机驱动器单元上安装和拆卸。叶轮转子是通过安装在电机轴上的6极外驱动磁体与叶轮转子内部成型的磁体之间的径向磁耦合力旋转的。叶轮-转子中心由一个动压轴承支撑。叶轮-转子轴承间隙为150μm时，通过轴承区的二次流约为外流的10%。TinyPump在3公斤仔猪的心肺转流研究中的应用表明，与儿科BioPump BP-50相比，其性能更优越。TinyPump还用于支持单心室模型的肺循环，以显示稳定的肺循环。TinyPump还被用作3.5公斤的猪和10公斤的柴巴山羊的左心室辅助装置，表现出稳定的低流量、非溶血性和生物相容性的循环支持长达两周。这项研究继续证明，10公斤柴巴山羊在1-2个月内具有稳定的生物相容性能。较少

This study addresses design and development of advanced circulatory support devices intended for short and intermediate duration of at least one month without requiring anti-coagulation therapy in children and adults, for allowing complete recovery, or for bridging to more advanced treatment modalities such as implantable devices or heart transplantation.To achieve the goal, for adult applications a disposable, magnetically levitated (Mag-lev) centrifugal blood pump having a prime volume of 23ml was designed by utilizing a compact magnetic bearing. The compact magnetic bearing was implemented by combining two-degree-of freedom active magnetic bearing in X- and Y- directions with permanent magnets passively restoring the position of impeller rotor in the axial and tilting axes. The rotation of impeller was attained through radial magnetic coupling between the inner driver magnet mounted on the motor shaft and the follower magnet molded inside the impeller-rotor. The pump performance ana … More lysis showed the maximum head pressure of 800mmHg against the pump flow of 5L/min at the rotational speed of 4500rpm. The hemolysis study revealed that the mechanical damage to blood cell elements was about the half that of the clinically used BioPump BPX-80. To date in vivo study using calves has shown that the pump system can meet requirements for one-week circulatory support in adult patients with minimum requirement of anti-coagulation therapy.As for pediatric application, a miniature centrifugal blood pump TinyPump having prime volume of 5ml and stable low flow control capability to 0.2L/min has been designed for 3-10Kg neonates and infants. The diameter of the impeller rotor is 30mm with six straight vanes resulting in the external diameter of the pump to be 50mm. The pump head is disposable, and easily attached and detached from the re-usable motor driver unit. The impeller rotor is rotated by radial magnetic coupling force between the 6 pole external drive magnets mounted on the motor shaft and the magnets molded inside the impeller-rotor. The impeller-rotor is supported by a hydrodynamic bearing at its center. The gap clearance of 150μm in the bearing of the impeller-rotor resulted in the secondary flow through the bearing area to be about 10% of the external flow. The application of the TinyPump for heart-lung bypass studies in 3Kg piglets revealed superior performance in comparison against the pediatric BioPump BP-50. The TinyPump was also used to support lung circulation in the single ventricle model to show stable pulmonary circulation. The TinyPump has also been used as a left ventricular assist device in the 3.5Kg swine and 10Kg Shiba-goats, demonstrating stable low flow, non-hemolytic and biocompatible support of circulation to the period up to two weeks. The study continues to demonstrate the stable and biocompatible performance in 10Kg Shiba-goats for the duration of 1-2 months. Less