Specific absorption rates and induced current distributions in an anatomically based human model for plane-wave...

Area of Science:

• Biophysics
• Computational Electromagnetics
• Medical Physics

Background:

• Previous studies reported specific absorption rates (SAR) and induced currents for lower frequencies (20-100 MHz) using a 5,628-cell human model.
• Advancements in computational power and modeling techniques enable higher resolution simulations.

Purpose of the Study:

• To extend SAR calculations to higher frequencies (up to 915 MHz) using a more detailed human body model.
• To investigate frequency-dependent SAR in various organs and body regions.
• To analyze the impact of grounding on SAR distribution.

Main Methods:

• Utilized a high-resolution, 45,024-cell anatomically based human body model.
• Employed the finite-difference time-domain (FDTD) method for electromagnetic wave absorption calculations.
• Calculated local, layer-averaged, and whole-body-averaged SAR for frequencies from 100-915 MHz.

Main Results:

• Highest part-body-averaged SAR for the head and neck region, including brain and eyes, observed at 200 MHz (isolated model) and 150 MHz (grounded model).
• Specific absorption rates for the eyes showed a consistent increase for frequencies above 350 MHz.
• Detailed SAR distributions were calculated for organs like the brain, eyes, heart, lungs, liver, kidneys, and intestines.

Conclusions:

• The high-resolution model provides detailed insights into human body exposure to radiofrequency electromagnetic fields.
• Frequency and grounding conditions significantly influence SAR distribution, particularly in the head and neck region.
• Findings are consistent with some existing experimental data and highlight the importance of high-resolution modeling for accurate SAR assessment.