基于亥姆霍兹线圈装置的磁热疗优化方法  

Research on Optimization Method of Magnetic Hyperthermia Based on Helmholtz Coil Device

作　　者：汤云东[1] 丁宇彬 金涛[2] Tang Yundong;Ding Yubin;Jin Tao(College of Physics and Information Engineering Fuzhou University,Fuzhou 350108,China;College of Electrical Engineering and Automation Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学物理与信息工程学院,福州350108 [2]福州大学电气工程与自动化学院,福州350108

出　　处：《电工技术学报》2023年第5期1248-1260,共13页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(62071124);福建省自然科学基金(2020J01464)资助项目。

摘　　要：该文研究了两种常见亥姆霍兹线圈产生磁场的均匀性,并根据装置线圈所产生磁场作用下的生物组织治疗温度分布分析了磁场均匀性对治疗效果的影响。其中,文中的磁纳米粒子(MNPs)以磁流体形式注射进肿瘤区域并假定以注射点为中心呈现高斯分布。该文在多种约束条件下应用改进粒子群算法优化了磁场的频率和强度、磁纳米粒子粒径,以及磁纳米粒子体积分数等参数,而涉及的约束条件包括治疗最高安全温度、治疗磁场安全范围上限、MNPs粒径范围,以及MNPs产热有效条件等。同时,该文以累积等效分钟数来评估圆形和正方形亥姆霍兹线圈及理想磁场在不同血液灌注率下的细胞热损伤程度。研究结果表明,正方形亥姆霍兹线圈相比于圆形线圈能产生更大范围的匀强磁场,这使其磁热疗效果更接近于理想磁场情况。同时,考虑温度依赖的血液灌注率相比定值情况具有更高的治疗温度。The treatment magnetic field usually presents an inhomogeneous distribution inside a real therapeutic equipment during magnetic hyperthermia,which will ultimately affect the treatment effects due to its unsatisfactory distribution of treatment temperature inside tumor region.However,previous literature has paid less attention to optimize the uniformity for magnetic field device and also to investigate its influences on the treatment effect during magnetic hyperthermia.Furthermore,the magnetic nanoparticles(MNPs)concentration under the same magnetic fluid dose is expected to have a value as small as possible in order to reduce the effect of the MNPs residual inside bio-tissue,which however was also rarely reported by the existing researches.This article investigates the therapeutic magnetic field for circular and square Helmholtz coil devices,analyzes the influence of magnetic field uniformity on the therapeutic effect by evaluating the temperature distribution of biological tissue due to the applied magnetic field,and also discusses the influence of different magnetic fields on the cumulative equivalent heating minutes at 43℃under two different blood perfusion rates.In addition,this study proposes an improved particle swarm optimization algorithm considering several constraints in order to obtain the minimum volume fraction of MNPs at the injection point and the corresponding optimized properties for MNPs radius and magnetic field at this time.The proposed constraints involved in this study consist of the maximum safe temperature for treatment,the safe upper limit of treatment magnetic field,the size range of MNPs,and the effective conditions for MNPs heat generation.The partial differential equations involved magnetic field and temperature field are solved using finite element method for the proposed Helmholtz coil devices and a three-dimensional mouse model,respectively.The MNPs inside the proposed tumor region are assumed to have a Gaussian distribution centered on the injection point.Simulation results demo

关 键 词：磁热疗 粒子群优化算法 亥姆霍兹线圈 血液灌注率 磁场 温度场 

分 类 号：TM154.1[电气工程—电工理论与新技术] R730.5[医药卫生—肿瘤]