High Fidelity Human Meshes
Biological Meshes for Anatomical Accuracy
If greater precision in the human body mesh is required, Remcom also offers high fidelity human meshes for both full body and head/shoulders regions. These meshes offer unparalleled precision, with an astonishing level of detail,particularly useful for designing implantable devices or in any design situation where anatomical accuracy is crucial. These are provided by NMR Hershey.
- High Fidelity Male Head/Shoulders Mesh
Made up of 2 mm x 2 mm x 2.5 mm (vertical direction) FDTD cells, 17 tissue types and an overall mesh size of 309 x 177 x 161 cells. Additional space may be added around the mesh for insertion of phone handset or other electronic devices. The mesh size as provided is about 8 million cells and requires approximately 256 MB of RAM for XFdtd® calculation.
High Fidelity Male Body Mesh
Made up of 5 mm cubical FDTD mesh cells, 23 different tissue types, and an overall mesh size of 136 x 87 x 397 cells. This mesh as provided is about 4 million cells and requires roughly 128 MB of RAM for XFdtd calculations.
High Fidelity Female Body Mesh
Made up of 5 mm cubical FDTD mesh cells, 34 unique tissue types, and an overall mesh size of 135 x 85 x 372 cells. This mesh as provided is about 4 million cells and requires roughly 128 MB of RAM for XFdtd calculations.
All three high fidelity meshes include the capability to automatically adjust the permittivity and conductivity of the tissues for any specified frequency between 1 MHz and 20 GHz,saving the user the tedious effort of typing in these parameters for each tissue type in the mesh as the frequency of interest changes. In addition to automatically providing single-frequency tissue parameters, the human head and both human body meshes also have the ability to make ultra-wide-bandwidth (UWB) calculations for transient electromagnetic fields. An example of this capability is available.
These high fidelity meshes provide highly accurate detail for internal body structures, necessary when internal EM fields are important, for example with implanted medical devices. To protect the intellectual property of both The Hershey Medical Center and Remcom Inc., these meshes are provided in an encrypted format so that they can be used only with XFdtd. The user may modify and save the meshes, but the modified meshes will then be usable only by XFdtd. A special license is provided with each mesh, allowing it to be utilized by XFdtd.
Also, it should be understood that these meshes may not be used by organizations which may be competing with the NMR group at Hershey Medical Center for funding or prior publication of research results.
These complimentary animal meshes are provided by The Radio Frequency Branch of the Human Effectiveness Division of the Air Force Research Lab at Brooks Air Force Base.
The complimentary animal meshes can be downloaded here.
FDTD For Biological Calculations
According to the Federal Communications Commission of the United States as stated in OET Bulletin 65, "Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields", Supplement C:
Currently, the finite-difference time-domain (FDTD) algorithm is the most widely accepted computational method for SAR modeling". Furthermore, in FCC Part 95 Section 603(f) it is stated: "Applications for equipment authorization of devices operating under this section must contain a finite difference time domain (FDTD) computational modeling report showing compliance with these provisions for fundamental emissions."
Remcom's XFdtd software is based on the FDTD method and is routinely tested for SAR calculation accuracy. Remcom offers the SAM head and Remcom biomeshes in part to aid customers in complying with FCC limits on SAR. The biomeshes are based on measured data. They and the SAM head can provide accurate estimates of SAR when used with a representative XFdtd model of the device. The accuracy of the device model can be established by comparing XFdtd calculations of radiated power to measurements. However, XFdtd and the Remcom biomeshes are not guaranteed to provide SAR calculations that will be acceptable to the FCC and are furnished without liability.