利用可视人数据建立植入式电子装置人体通信模型的研究

It is important to model the physical layer electromagnetic process of intrabody communication to simplify the antenna design, realization duplex communication and closed-loop control with less consumption for implantable electronic device. Based on the modeling of quasistatic field and validation experiment research previous, this research will focus on the existing problems such as electromagnetic model or equivalent circuit model restricted to local organs for intrabody communication of implantable devices, and will work on such as segmentation, registration and reconstruction on the visible human data, and develop an efficiency and accuracy algorithm of the finite element simulation with multiple scales suitable for electrical signals transmission. A simulation analysis platform for implantable devices take advantage of intrabody communication will be established. And the process of electrical signals transmit from "surface to inside" or "inside to surface" can be repeated.According to the distribution of current of different tissues, the global human geometrical characteristics suitable for signal transmission should be abstracted. The process of intrabody communication based on the equivalent current dipole could be described with Laplacian or current density. Then the conditions of reciprocity theorem will be discussed in order to realize the physical layer modeling of duplex communication for implantable devices. Moreover, the evaluation index of electrode coupling efficiency will be proposed to evaluate the optimization design electrode scheme. This study not only realize the model with whole body and generality for implantable devices using intrabody communication, but also provides the electromagnetic theory basis for the development of digital medical.

构建人体通信物理层电磁模型，对植入式电子装置简化天线设计，实现更低功耗的双向通信和闭环控制具有重要意义。本研究将在前期人体准静态场建模和验证实验研究基础上，针对现有植入式装置人体通信研究多限于局部器官电磁建模或等效电路建模的现状，通过对可视人数据进行分割、配准、重构，研究适合电信号传输的高效且兼顾准确度的多尺度有限元仿真算法，建立植入式装置人体通信的仿真分析平台，真实描述电信号"体内-体表"、"体表-体内"传输过程；比较人体不同组织中电流分布，简化抽象适于信号传输的全局人体几何特征，以等效电流偶极子的体表电流密度或Laplacian描述人体通信过程，进而讨论互易性定理在人体的成立条件，实现对植入式装置体内外双向人体通信的物理层建模；结合仿真平台和人体模型研究植入式电极评价指标，优化电极设计方案。本研究不仅解决植入式装置人体通信建模的全局化和通用性问题，更为电磁理论在数字医学的发展提供依据。

项目组研究了植入式电子装置体内通信在人体组织准静态电场中的传输机理，重点讨论了人体组织电容效应、传播效应、边界效应、磁感应效应的满足条件；针对美国可视人数据集采取了分割、配准、重构的方法，建立了具有近似人体介电特性的三维数字化人体，在此基础上建立了准静态场下全人体的可视化有限元仿真模型；进一步将穿戴式设备，以及设备之间的耦合阻抗等效成电路网络增加到有限元模型中，构建出场-路结合的植入式装置体内通信模型；采用3D打印机打出人体多种等效组织的轮廓，制作出具有不同电导率的人体多层等效仿体，开展实物仿体实验，验证场路结合有限元模型求解结果的正确性；最后开展人体在体实验，充分表明本研究提出的基于可视人数据的植入式设备体内通信的场路结合信道模型，较先前的抽象几何体电场模型有着更好地符合性。