Frequency Tracking of Resonance Frequency Variation of L-C Circuits for Wireless Energy Transmission to Medical Devices in Human Organs

  • Gimm, Yoon-Myoung (Department of Electronics and Electrical Engineering, Dankook University) ;
  • Ju, Young-Jun (Department of Electronics and Electrical Engineering, Dankook University) ;
  • Lee, Yu-Ri (Department of Electronics and Electrical Engineering, Dankook University) ;
  • Lee, Dong-Yeol (Department of Electronics and Electrical Engineering, Dankook University) ;
  • Wang, Jong-Wook (EMF Safety Inc.)
  • Received : 2011.05.16
  • Published : 2011.12.31


A capsular endoscope (CE) for inspection of the large intestine requires a motor for backward navigation against the autonomous travel in the intestine. This study proposes an HF power system for generating a magnetic field and for delivering wireless power to the internal or implanted medical devices. The magnetic field is generated by a wound coil (L) around a wooden frame, and the current is driven to the coil through a resonating capacitor (C). The characteristics of the resonance frequency shifting of the L-C series circuit are analyzed. A stable magnetic field intensity in the field coil is maintained by a specially designed frequency tracking system that automatically follows the L-C resonance frequency. Testing confirmed that the oscillation system tracks well the parameter changes of the electric components caused by the operating conditions or environmental variations.


Wireless Power Transmission;L-C Resonance;Frequency Tracking Oscillator;Magnetic Field Generator


Supported by : Intelligent Microsystem Center


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