节点文献
人工心脏的经皮传能系统的研究
Transcutaneous Energy Transmission System for Artificial Heart
【作者】 马纪梅；
【作者基本信息】 河北工业大学 ， 电气工程， 2011， 博士
【摘要】 随着生命科学和生物技术的迅速发展,以人工心脏为代表的医疗植入装置的研究取得了长足的进步,将来人工心脏有可能像心脏起搏器一样得到广泛应用。1995年世界首例永久性人工心脏被植入至患者腹腔内,通过从胸腔引出的导线直接与体外的电池组相连进行供电,这种方式极易造成交叉感染,引发各种并发症,甚至会危及患者生命,因而应用受限。现在欧美临床上人工心脏的供能方式主要集中在经皮传能系统方面,它通过电磁耦合将置于体外的初级线圈携带的能量传递给植入体内的次级线圈以驱动人工心脏工作,人工心脏和体外电源没有任何导线连接,避免了交叉感染,极大地提高了患者的生命质量。随着该技术的发展完善,必将会推动医疗领域无创伤、低风险治疗的进一步发展,具有重要的研究价值和广阔的应用前景。本论文建立了人工心脏的经皮传能系统,主要包括能量的经皮传输和体内、外温度信息的无线传输通道。主要工作如下:一、基于传统的罐型磁芯,以有限元数值求解方法为支撑,考虑铁芯材料、铁芯结构参数、位置以及线圈轴向错位等因素,进行了电磁场数值模拟与分析,研究变压器的耦合性能及稳定性,以实现基于数值模拟的经皮变压器设计,解决了由于体内空间和体积受限而导致的经皮变压器设计的合理性与传输效率之间的矛盾。二、建立并基于经皮变压器的互感模型,对经皮传能系统中的经皮变压器进行性能分析,并对经皮传能系统的几种可行补偿方式进行了对比分析。三、设计并制作罐型铁氧体铁芯经皮变压器和罐型组件磁芯PM(PM-Pot Module Cores)经皮变压器;完成罐型和PM经皮变压器的电感值、耦合性能与传输性能的测量与定量分析;研究了初、次级不同补偿方式下的传输性能和频率特性。四、采用有限元数值求解方法,对经皮变压器的温度场进行场域计算与分析;研究次级铁芯温升值与负载功率间的关系;并以次级铁芯温升值为标准调整外加电源,以保证人工心脏吸收功率恒定;以JASK2000无线通信开发板为基础,建立体内外信息传输通道。五、设计并制作了体内充电电池充放电电路板,以实现体内充电电池的管理;基于能量守恒定理,计算并分析充电电池的放电时间,并进行了三周期的充放电试验与分析。
【Abstract】 With the rapid development of life science and bio-engineering, the research of implanted medical device, especially the totally artificial heart (TAH), has made great progress, and the TAH with the character of miniaturization, durability and low-resistance, might be used as widely as the artificial pacemaker. The original electric artificial heart is connected with the battery by the wires which penetrate the skin, leading to high ratio of cross-infection. With the use of transcutaneous energy transmission system (TETS) which does not have any physical connection with the outer battery to drive the TAH, it has greatly prevented infection complications and improved the life quality of the patients. With the development and improvement of this technology, non-invasion and low-risk treatment in medical field will be further promoted, thus it has great research value and application prospect.In this paper the TETS, which consists of the transcutaneous energy transmission and temperature data communication through intact skin to power a TAH, has been designed and built. Main tasks are as follows:1. The factors affecting the contactless transformer of TETS coupling efficiency(k) are analyzed. With the help of the finite element analysis software, the coupling performance and stability of the transformer are analyzed. And then core material, air gap, geometrical parameters, and coils axial displacement are selected to study their effects on coupling coefficient. By simulating with various values, the transformer is designed. Then a type of high coupling and small size coil is proposed in this paper, which solve the design contradiction between transcutaneous transformer and transmission efficiency.2. The working frequency 100 kHz of the TETS is determined according to the primary and secondary current ratio of the transcutaneous transformer. Compared of various compensation methods, it can be obtained theoretically that two capacitors added in series on both sides to compensate the leakage inductances is more suitable for the TETS.3. The coupling and energy transmission characteristics mainly including three aspects of the TETS are studied experimentally. Firstly, the coupling for the pot and PM (Pot Module Cores) core transformer with frequency, load, air gap and horizontal displacement is investigated. Secondly, the power transmission characteristic of the TETS with frequency, load, air gap and horizontal displacement is studied with the experimental pot core transformer. Lastly, the applicability of various compensation methods is studied experimentally. The most efficient compensation method of the TETS for TAH, of which two capacitors are added in series on both sides, is obtained experimentally.4. The temperature field of transcutaneous transformer is established. Furthermore, an information transmission system is proposed. Through monitoring the temperature of secondary core which reflects the value of load power, the change of temperature can adjust the input power of the primary coil to achieve high system reliability. And a transcutaneous data communication system based on JASK2000 development board is built.5. The hardware platform of charging and discharging experiments is built. On the basis of that, the expected life-span of the TETS using the energy conservation theory is deduced, and accordingly its validity is approved. Actural 3-period charging and discharging experiments is operated.