考虑粒子分散性的磁热疗温度分布评估及优化

Evaluation and optimization for temperature distribution in magnetic hyperthermia considering particle dispersion

针对磁纳米粒子(magnetic nanoparticles,MNPs)建模过于理想化的问题,在肿瘤模型内构建了多种单分散和多分散的MNPs.在此基础上,以MNPs的功耗为输入通过求解生物传热方程来预测模型治疗温度,继而研究了不同分散性MNPs对磁热疗治疗效果的影响差异.此外,考虑一种接近真实的多分散性MNPs模型中构建了基于模糊自适应比例积分微分磁热疗控制系统,该系统能通过温度反馈实时控制磁热疗治疗温度处于临界值46℃,解决了因MNPs分布不均匀性和多分散性导致目标区域局部温度难以稳定在最佳治疗温度46℃的问题.仿真结果表明:在相同的治疗条件下,MNPs粒径集中程度和肿瘤区粒子分布均匀性的提高均可有效地改善治疗效果,而所设计的控制系统能够以较快的速度使最高温度稳定在最优值46℃,显著提高治疗效果.

In view of the problem of too idealized modeling for magnetic nanoparticles,a variety of monodisperse and polydisperse magnetic nanoparticles(MNPs)distributions were constructed for a proposed tumor model.On this basis,the treatment temperature for the proposed model was predicted by solving the biological heat transfer equation after taking the power consumption of MNPs as the input,and the therapeutic effect differences due to different dispersed MNPs during magnetic hyperthermia were further investigated.In addition,a fuzzy adaptive proportional-integral-differential control system for magnetic hyperthermia was constructed after considering a more real distribution for polydisperse MNPs.This system can accurately control the treatment temperature within a critical value(46°C)by temperature feedback during magnetic hyperthermia,which solves the problem that the local temperature of target area is difficult to stabilize at the optimal safe treatment temperature due to the inhomogeneous distribution and polydispersity of MNPs.The simulation results demonstrate that the treatment effect can be improved by increasing the aggregation degree of MNPs size and the uniformity of MNPs distribution in the tumor area under the same treatment conditions.Furthermore,the control system proposed can significantly improve the treatment effect by quickly stabilizing the maximum temperature to an optimal value,46°C.