VP4-05: Study on Wireless Power Transmission System for Real-Time Telemetry  of Mouse Activity and Body Temperature
Creators: Tatsuki Omori
Fumihiro Sato
Yoshiki Furuya and Syu Sasaki
Publisher: name: IEEE
Year: 2023

Interdisciplinary and Emerging Topics: Biomedical Applications; Magnetic Fluids and Separations; New Applications and Other Emerging Topics (Virtual)
Animal experimentation involves recording changes in biological information such as body temperature, heart rate, blood pressure, and activity level during the experiment using specialized equipment. To take the recording of activity levels as an example, there are methods to analyze videos taken by infrared cameras[1], to refer to the number of revolutions of a spinning wheel[2], and so on. However, for experiments that require accurate biometric information, the use of an implantable biometric device, rather than the above devices, is one of the most suitable options. Implantable biometric acquisition devices often rely on batteries for their means of power supply[3],[4],[5],[6]. However, when a battery is implanted with the device, it must be small and lightweight so that the weight of the battery does not become a burden on the animal experimentation, and its capacity cannot be ensured. Therefore, it is impossible to conduct long-term experiments or to monitor biological information in real time. For this reason, a method has been proposed in which, instead of batteries, a power receiving coil is implanted in the animal experimentation, and power is supplied by a power transmitting coil installed around the rearing cage. Since this method can constantly send electric power, the acquired data can be transferred to an external recording terminal such as a PC in a very short cycle, enabling real-time monitoring of biological information. However, in prior research, it has been suggested that the power supply may become unstable due to the heat generated in the receiving coil from the power consumption and the position and posture of the animal experimentation[7]. To solve these problems and ensure stable power supply, we worked on the creation of a power transmission coil that generates a uniform magnetic field and conducted demonstration experiments. Figure 1 shows a model diagram of the created power transmission coil. Figure 2 shows the measured and graphed magnetic field distribution at a height of 0 mm from the top of the power transmission coil, indicating that the magnetic field is uniform.References: [1] K. Kobayashi, N. Shimizu, S. Matsushita and T. Murata, "The assessment of mouse spontaneous locomotor activity using motion picture," in Journal of Pharmacological Science, vol. 143, issue 2, pp. 83-88 (2020) [2] D. M. Edgar et al., "Influence of running wheel activity on free-running sleep/wake and drinking circadian rhythms in mice," in Physiology & Behavior, vol. 50, issue 2, pp. 373-378 (1991) [3] H. Mei, K. A. Thackston, R. A. Bercich, J. G. R. Jefferys and P. P. Irazoqui, "Cavity Resonator Wireless Power Transfer System for Freely Moving Animal Experiments," in IEEE Transactions on Biomedical Engineering, vol. 64, no. 4, pp. 775-785 (2017) [4] S. T. Lee, P. A. Williams, C. E. Braine, D. -T. Lin, S. W. M. John and P. P. Irazoqui, "A Miniature, Fiber-Coupled, Wireless, Deep-Brain Optogenetic Stimulator," in IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 23, no. 4, pp. 655-664 (2015) [5] T. A. Szuts et al., "A wireless multi-channel neural amplifier for freely moving animals," in Nature Neuroscience, vol. 14, no. 2, pp. 263-269 (2011) [6] Fan D, Rich D, Holtzman T, Ruther P, Dalley JW, Lopez A, Rossi MA, Barter JW, Salas-Meza D, Herwik S, Holzhammer T, Morizio J, Yin HH. "A wireless multi-channel recording system for freely behaving mice and rats," in PLOS ONE 6(7). [7] S. T. Warren, F. Lev, A. Daniel, "Rotating Field Inductive Data Telemetry and power Transfer in an Implantable Medical Device System," U.S. Patent 2009069869-A1 (2007)