This Small Business Innovation Research Phase I project will develop a low-cost, high-performance, user-accessible Finite Difference Time Domain (FDTD) based simulator of wireless Body Area Networks (BANs), written entirely with the MATLAB software package. The simulator, with real-time visualization of electromagnetic fields in and around the human body, is to be used for training of the next generation of biomedical and electrical engineers, and medical students. The proposed software will give students an intuitive feel for electromagnetic wave propagation, wave scattering and absorption by material structures, and the effects on signal integrity due to human body interference. It is also intended for performing applied and fundamental research in the area of wireless healthcare. The simulator supports mathematical foundations and software implementations of the FDTD method, and modern broadband/ultrawideband communication and localization techniques. It will be developed by Neva Electromagnetics, LLC (Neva EM) in collaboration with Worcester Polytechnic Institute, Michigan State University, and Harvard University Medical School. The key feature of the simulator is a new model for small coil antennas, which are commonly used in wireless healthcare. This model is based on the FDTD Dipole Moment (DM) method, a simple and powerful technique recently developed at Pennsylvania State University.
The broader impact and the commercial potential of this project is in transition of the BAN electromagnetic modeling tools to a much wider audience of scholars and engineers via the accessible and highly visual MATLAB platform. In the past decade, wireless sensor networks have emerged as an industry showing great potential to stimulate the US economy. The most promising area of economic growth in sensor networks today may be the wireless healthcare industry, including wireless BANs. The developed product targets Received Signal Strength (RSS), Time of Arrival (TOA), and Direction of Arrival (DOA) estimations for basic small antenna sources (small coil and dipole antennas) in BANs, various pulse forms, and different antenna topologies. The product is capable of modeling multi-sensor networks and body-scanning antenna arrays, which are subject to mutual coupling between individual radiators. A large library of high-resolution, realistic body meshes exported into MATLAB is included. Due to its flexibility, the product also targets potential secondary commercial and educational markets: body-worn antennas, ground-penetrating radar, remote sensing applications, and underwater wireless links. Open-source I/O and parameter identification MATLAB codes make it possible to customize the simulator to address the unique needs of potential customers from academia, industry, and government.
For the first time, NEVA Electromagnetics LLC has generated a software package, a digitized human body mesh library, and a procedure to create, manipulate, and use a representative collection of human body meshes with organs for the most accessible simulation software platform to colleges and universities – MATLABR. Together with the material properties of the tissues, including electric permittivity and conductivity, higher fidelity simulations can be solved using existing or custom electromagnetic solvers to offer young researchers and students immediate low-cost practice and discovery tools. The applications of models such as these are numerous. Electrostatic and quasielectrostatic simulations can model human body capacitance, capacitive touchpads and touchscreens, human exposure to electric fields, transcranial stimulation with electrodes or pulsing coils. The electrodynamic simulations concern antenna radiation close to the body, radio-frequency sensors, and body-area sensor networks. All those results could be directly coupled with the MATLAB signal processing tools. Study of electromagnetic signal interaction with human body is not only a rapidly growing area of modern biomedical research but also an exciting pathway to spark student interest in electrical engineering, biomedical engineering, and applied electromagnetics. The typical problems to be solved are divided into two sets. The first one is generally related to the impact of cellphones, Magnetic Resonance Imaging, power lines, and other potentially detrimental technologies on the human body. Conversely, the second set studies very positive electromagnetic effects such as pacemaker technology, electromagnetic diagnosis and treatment of tumors, transcranial magnetic stimulation of the brain, direct current transcranial stimulation, and in-body localization and communication using wireless body-area networks. The key to electromagnetic simulations of any kind are high-fidelity models or ‘meshes’ of human bodies, inner organs, bones, and other human tissues. These meshes are digitized representations of the living, possibly even moving tissues. In a simple form, every tissue is considered as a combination of interconnecting small triangles and/or tetrahedra. The meshes can be further inserted into various modern professional simulation software packages.
