Abstract
In this article, we reconstruct the internal electric field due to a dipole antenna embedded in a dielectric phantom for developing a noninvasive specific absorption rate (SAR) measurement system. The reconstruction method is based on the surface equivalent theorem and boundary conditions, which relate the external field radiated from the embedded antenna to equivalent electromagnetic surface currents on the human body. The electric field data sampled at spatial points on a surface enclosing the phantom are used in the inverse calculation. All field integrals are discretized and numerically solved to obtain the electromagnetic currents on the phantom's surface. The internal electric field distribution and SAR value in a phantom can be calculated from the reconstructed surface currents if the electric properties of the phantom are known. The validity of the method was demonstrated numerically and experimentally using a dipole antenna embedded in the lossy rectangular phantom, which has a dielectric constant close to human skin tissue at 2.5 GHz. Comparison with forward numerical simulations has shown that the surface current and electric field distribution can be predicted with great precision. Carefully performing the experiments using a self-made phantom validated our numerical demonstration and provided satisfactory reconstruction results.
Highlights
R ECENTLY many kinds of wireless biomedical telemetry devices are deployed for disease prevention, diagnosis, monitoring, and even therapeutic functions
Even though internal devices, such as electrical pacemakers for the heart, or wireless capsule endoscopy (WCE) pills for monitoring the gastrointestinal tract are successful clinically, some concerns about the possible health effects of exposure to electromagnetic fields radiated from these devices are hard to be completely cleared up
We have proposed an source reconstruction (SR) method to obtain the internal electric field of the phantom with an embedded antenna
Summary
R ECENTLY many kinds of wireless biomedical telemetry devices are deployed for disease prevention, diagnosis, monitoring, and even therapeutic functions. These devices are installed and operated at various locations. Date of publication June 30, 2021; date of current version October 13, 2021. For a wireless device that communicates with equipment outside of the human body, a large power supply is required to compensate the internal propagation loss. The evaluation and measurement of SAR are indispensable for biomedical telemetry devices and electronic equipment that radiates electromagnetic (EM) waves
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
