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Electromagnetic interference (EMI) from mobile phones affecting implanted cardiac pacemakers has become a recent concern. In previous numerical computations of the EMI, a half-wavelength dipole antenna has been employed as a radiator of electromagnetic waves. However, current mobile phones are generally equipped with an internal antenna. Furthermore, recent mobile phone systems are operated at higher frequencies, i.e., 2 GHz, whereas lower frequencies around 900 MHz have been assumed in the previous studies. In this study, a mobile phone with an internal antenna was modeled with a planar inverted-F antenna (PIFA) mounted on a metallic case, in order to calculate the interference voltage induced at the pacemaker due to the internal antenna. The PIFA was then scanned in a plane parallel to the torso surface, in order to calculate the interference voltage at each position and to clarify the detailed relationship between the interference voltage and the position of the antenna. Moreover, the interference voltage was experimentally evaluated to validate the numerical calculations. It is shown that the PIFA has interference voltage characteristics, which differ from those of the half-wavelength dipole antenna. Comparing the calculation with the measurement, both results show the same tendency, especially around the position of maximum interference. Therefore, the measured results indicate the validity of the numerical results. [ABSTRACT FROM AUTHOR]

An in-body wireless communication system has attracted increasing attention because it can replace the connectivity of biological telemetry monitoring. However, the human body is a very complex environment (lossy, dispersive, and inhomogeneous) and affects the electromagnetic (EM) wave in the near field. Moreover, the entire human geometry affects the radiation pattern in the far field. This communication presents the behavior of the EM wave in the near and far fields at 2.45 GHz when a dipole antenna (used as an implantable antenna) is embedded in the vicinity of the clavicle, upper arm, lower arm, and hand of a human body. The effect on the electric field and radiation performance is simulated by the finite-difference time-domain method. By introducing a three-layered phantom, the antenna performance is confirmed. Moreover, the measured and simulated results are in good agreement with each other. The information derived from this study can be used in the evaluation of the link budget of in-body wireless communication. [ABSTRACT FROM AUTHOR]

Interstitial microwave hyperthermia is one of the modalities for cancer treatment that insert a thin microwave antenna into the affected part to selectively heat only the tumor. The authors are investigating this technique with an aim of clinical applications of this medical treatment for brain tumors. In the clinical treatment of brain tumors, it is more critical that “only the tumor parts be heated” than for the treatment of other tissues. Therefore, an antenna that can generate a localized heating pattern on the tumor is required. Although the heating pattern can be controlled here in the longitudinal direction of the antenna by using multiple antennas to form an array applicator, control of the heating pattern in the axial direction is relatively difficult. In this paper, to enable the heating pattern to be controlled in the axial direction, the authors introduced a coaxial-dipole antenna and improved its structure. In addition, they assumed that it was actually applied in the medical treatment of brain tumors and used a numerical calculation model that included a tumor created from MR images to verify the effectiveness of the improved coaxial-dipole antenna according to numerical calculations. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 31–38, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20390 [ABSTRACT FROM AUTHOR]

Microwave coagulation therapy (MCT) has been used mainly for the treatment of hepatocellular carcinoma (small cancer in the liver). In this therapy, a thin microwave antenna is inserted into the tumor. Using microwave radiation, the tumor is heated to a high temperature (at least 60 °C) and is killed by coagulation. In the MCT antenna used at present, there is the problem that the coagulation region is elongated along the antenna insertion direction so that the normal tissue around the tumor is also heated. It is desirable to heat the vicinity of the antenna tip in a spherical manner. In order to meet this requirement, a coaxial-dipole antenna is used and localized heating is realized. In this paper, first, by numerical analysis by the FDTD method and measurement of the SAR distribution, the usefulness of the coaxial-dipole antenna is demonstrated. Further, by computing the current distribution on the antenna, the reason for localization of the SAR by this antenna is studied. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(1): 16–23, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10049 [ABSTRACT FROM AUTHOR]

A correction to the article "Performance of Implantable Folded Dipole Antenna for In-Body Wireless Communication" by Ho-Yu Lin, Masaharu Takahashi, Kazuyuki Saito and Koichi Ito that was published in the January 9, 2014 issue is presented.