This paper investigates the accuracy of the finite-difference time-domain (FDTD) method for separately estimating coil conductor and radiative loss contributions.
Computation of Fields and SAR for MRI with FDTD Simulation
The simulation procedure allows the coil designer to get quick feedback on the performance of the device, without the time or cost of producing numerous prototypes. The further ability to simulate the structure in practical use, such as the coil around a body part, permits the designer to optimize the device under loaded conditions and ensure that the regulated limits such as SAR are within thresholds. In this article, a SAR analysis for an MRI system is presented using XFdtd.
Path Gain and SAR Analysis of On-Body Antenna Optimized for Hearing Instrument Applications
This presentation describes the simulation of a hearing instrument (HI) device. The design was simulated in the presence of a homogeneous SAM phantom and an anatomically correct, heterogeneous head model. The simulation results illustrate the differences between the head models and highlight the more acceptable results for improved device safety.
Proton-decoupled carbon magnetic resonance spectroscopy in human calf muscles at 7T using a multi-channel radiofrequency coil
Fast Estimate of Thermal Responses of Biological Bodies due to RF Exposure
A fast approach is proposed for estimating the thermal responses of biological bodies due to RF exposures. The approach is based on ANN models. The results obtained from the fast approach agree well with those calculated directly from the thermal solver. The advantage is that the approach is fast and is not dependent on the biological body and mesh sizes.
Case Study: Using Electromagnetic Simulation to Ensure EMC Compliance
KEC, a UK manufacturer of EMC interconnect components and cable harness assemblies, strengthened its market leadership and differentiated itself from the competition by offering a unique technology. Using Remcom’s XFdtd to model and simulate customers’ designs, KEC can identify problems early in the process and recommend corrections before the EMC certification stage. This enables customers to avoid costly mistakes and pass certification testing on the first try.
A Study on the Feasibility of the Deep Brain Stimulation (DBS) Electrode Localization Based on Scalp Electric Potential Recordings
Case Study: How Remcom Consulting Helped ReGear Launch a Deep Tissue Heating Device
When ReGear Life Sciences developed a new therapeutic deep heating garment for the shoulder, they needed to validate that the SAR value complied with all applicable FDA and FCC safety regulations before releasing the product to the market. Remcom performed EM simulations, made recommendations on a safer design, and provided the documentation necessary for ReGear to get approval for the product.
Case Study: MRI Coil Improvement for Cardiac Imaging in Mice
An Overview of Remcom's VariPose
Comparison of Radiofrequency Exposure of a Mouse and Foetuses at 900 MHz
In vivo studies involving radiofrequency (RF) exposure of rodents require detailed dosimetric analysis to enable correct interpretation of biological outcomes. Detailed anatomical models of mice—a female, a pregnant female, a male and a foetus—have been developed for analyses using finite difference numerical techniques.
Electromagnetic Simulation Cuts Time to Develop New MRI Coil by Two-Thirds
Electromagnetic Simulation Aids Development of Unique EEG Cap
Electromagnetic Simulation Helps Design Next Generation of MRI Equipment
Standardization of Computational Techniques for Compliance Evaluation of the Human Exposure in Automotive Environments
Measurements and FDTD Computations of the IEEE SCC 34 Spherical Bowl and Dipole Antenna
SAR and feedpoint impedance have been measured and FDTD computed for a spherical bowl and a l/2 dipole at 835 MHz according to procedures outlined by IEEE SCC 34, WG 1. Good agreement between measurement and FDTD computation was found both for the SAR distribution in the bowl and for the antenna feedpoint impedance.
Electromagnetic Simulation Used to Evaluate Safety of Combining EEG and MRI
Electromagnetic simulation software is being used to investigate the safety of an important research technique that integrates electroencephalography (EEG) with magnetic resonance imaging (MRI). The integration of these two analysis methods has the potential to improve investigations of brain activity because EEG offers high temporal resolution while MRI offers high spatial resolution. But concerns have arisen about temperature increases in sensitive brain tissues that could be caused by the current induced in the EEG electrodes by the radio frequency (RF) power generated by MRI.
Temperature and SAR Calculations for a Human Head Within Volume and Surface Coils at 64 and 300 MHz
Study of the Coupling Between Human Head and Cellular Phone Helical Antennas
The interaction between normal-mode helical antennas and human head models is analyzed, using both a novel accurate semi-analytical method and finite-difference time-domain (FDTD) simulations. The semi-analytical method is based on the combination of Green’s functions theory with the method of moments (Green/MoM) and is able to model arbitrarily shaped wire antennas radiating in the close proximity of layered lossy dielectric spheres representing simplified models of the human head.
Bandwidth, SAR, and Efficiency of Internal Mobile Phone Antennas
This paper presents a thorough investigation into the effects of several phone chassis-related parameters—length,width, thickness, and distance between the head and phone—on the bandwidth, efficiency, and specific absorption rate (SAR) characteristics of internal mobile phone antennas. The studied antenna-chassis combinations are located beside an anatomical head model in a position of actual handset use.