Affiliations: [a] Department of Biomedical Engineering, College of
Medicine, Dankook University, Chungchungnam-do, Korea | Doshisha University, Kyoto, Japan | Department of Human and Information Systems, Faculty
of Engineering, Gifu University, Gifu, Japan
Correspondence:
[*]
Corresponding author: Ilyong Park, Department of Biomedical
Engineering, College of Medicine, Dankook University, San 29, Anseo-dong,
Cheonan-si, Chungchungnam-do, 330-714, Korea. E-mail: [email protected]
Abstract: A popular technique for wireless power transfer and data
communication between fully implantable active medical devices and base
stations is inductive coupling. A weakness of current technology means that the
magnetic coupling coefficient is sharply decreased by variations in the
distance and misalignment between two coils. This can result in degradation of
communication and efficiency of power transfer between implants and external
devices. In this paper, a method to track the coil position of the implant
device using a 3-axis magnetic sensor module in the wireless remote controller
has been proposed for efficient power transfer and robust data communication.
The magnetic sensor module is implemented for obtaining the magnetic flux
vector of the magnet in the middle of the inner coil. Based on the obtained
magnetic flux vector, the pseudo-distance vector between the inner coil and the
outer coil can be calculated and the position of the inner coil can be tracked.
From experiments to evaluate the performance of the implemented remote
controller's ability to find the inner coil position, we found that our remote
controller could track the position of the inner coil of the implant device
with the averaged error range of 3.73 mm and increase to a maximum of about 30%
above the minimal power requirement for charging a battery of the mock-up
implant device. It is expected that the implemented remote controller can be
used for implantable active medical devices such as fully implantable middle
ear hearing devices.
Keywords: Wireless power transfer, implantable active medical device, inductive coupling, inner coil position tracking, 3-axis magnetic sensor module
