Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied. However, possible relationships between WPT exposure and human health have not been experimentally evaluated. In this study, we developed a new in vitro exposure system to evaluate the biological effects of magnetic resonant coupling WPT. The WPT was carried out using a self-resonant helical coil, which was designed to transfer the power with 85.4% efficiency at a 12.5 MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate (SAR) at the positions of the cell culture dishes match the respective reference levels stated in the ICNIRP guidelines. In this paper, the coil design for the magnetic resonant coupling in the in vitro exposure system and characteristics, such as power transfer efficiency, electric field and magnetic field distributions, and SAR of the exposure system, are described.

The use of carbohydrases and proteases in poultry production occasionally results in inconsistent physiological responses that are difficult to explain. However, it has previously been demonstrated that a substantial portion of the variation in enzyme efficacy is associated with the inherent ileal digestibility of starch, protein and lipid, and so an appreciation for the concentration of the undigested fractions of these nutrients in a diet may help to determine the magnitude and consistency of feed enzyme responses. Considering that the expense of in vivo physiological assays for the assessment of enzyme functional pattern is high, it is crucial to develop suitable in vitro methods to predict the magnitude of enzyme response. The purpose of the current paper is to describe inherent characteristics of poultry diets and feed ingredients in response to carbohydrases and proteases in order to aid the development of in vitro assays to predict feed enzyme functional patterns.