基于真实头模型的经颅磁声电刺激感应电流密度仿真分析

Simulation Analysis of Induced Current Density of Transcranial Magnetic-Acoustical Electrical Stimulation Based on Realistic Human Head Model

感应电流密度的聚焦性是实现精准神经调控的关键,其中头颅结构对于经颅磁声电刺激的感应电流密度分布具有重要影响。文中利用人体头部的CT图像,使用三维重构技术构建了真实头模型;对真实头模型进行经颅磁声电刺激的有限元仿真分析,获得了真实头模型内部的感应电流密度分布,并对仿真结果进行了评估。为了进一步探寻刺激效果和超声频率之间的关系,文中分别使用300 kHz、400 kHz、500 kHz的超声波对真实头模型施加经颅磁声电刺激。仿真结果显示,超声信号频率的增加会导致刺激强度、刺激长度以及聚焦面积的增加。该结果表明经颅磁声电刺激具有良好的深度刺激特性和聚焦特性,有望对深处脑区神经元进行无创调控。

The focusing characteristics of the induced current density is the key to precise neural regulation.The structure of the skull has an important influence on the induced current density distribution of TMAES.Therefore,a realistic human head model based on the CT data of the human head is established using the 3D calculating method.The finite element method is used to simulate the model during TMAES.The distribution of induced current density is obtained and subsequently evaluated.In order to further explore the relationship between the stimulus effect and the ultrasound frequency,ultrasonic waves with frequencies of 300 kHz,400 kHz and 500 kHz are applied on the realistic human head model during TMAES.The results show that the increase of the frequency of the ultrasonic signal can increase the stimulation intensity,the stimulation length and the focus area.These results indicate that TMAES has good depth stimulation and focusing characteristics,and has the potential to noninvasively modulate neurons deep in the brain.