Journal of Biomedical Engineering Research (대한의용생체공학회:의공학회지)

The Korean Society of Medical and Biological Engineering (대한의용생체공학회)
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320-Channel Multi-Frequency Trans-Admittance Scanner(TAS) for Anomaly Detection

도전율 및 유전율이 다른 병소의 검출을 위한 320-채널 다주파수 Trans-Admittance Scanner(TAS)

  • Oh, Tong-In (Department of Biomedical Engineering College of Electronics and Information, Kyung Hee University) ;
  • Lee, Min-Hyoung (Department of Biomedical Engineering College of Electronics and Information, Kyung Hee University) ;
  • Kim, Hee-Jin (Department of Biomedical Engineering College of Electronics and Information, Kyung Hee University) ;
  • Woo, Eung-Je (Department of Biomedical Engineering College of Electronics and Information, Kyung Hee University)
  • 오동인 (경희대학교 전자정보대학 동서의료공학과) ;
  • 이민형 (경희대학교 전자정보대학 동서의료공학과) ;
  • 김희진 (경희대학교 전자정보대학 동서의료공학과) ;
  • 우응제 (경희대학교 전자정보대학 동서의료공학과)
  • Published : 2007.02.28
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Abstract

In order to collect information on local distribution of conductivity and permittivity underneath a scan probe, we developed a multi-frequency trans-admittance scanner (TAS). Applying a sinusoidal voltage with variable frequency on a chosen distal part of a human body, we measure exit currents from 320 grounded electrodes placed on a chosen surface of the subject. The electrodes are packaged inside a small and light scan probe. The system includes one voltage source and 17 digital ammeters. Front-end of each ammeter is a current-to-voltage converter with virtual grounding of a chosen electrode. The rest of the ammeter is a voltmeter performing digital phase-sensitive demodulation. Using resistor loads, we calibrate the system including the scan probe to compensate frequency-dependent variability of current measurements and also inter-channel variability among multiple. We found that SNR of each ammeter is about 85dB and the minimal measurable current is 5nA. Using saline phantoms with objects made from TX-151, we verified the performance of the lesion estimation algorithm. The error rate of the depth estimation was about 19.7%. For the size estimate, the error rate was about 15.3%. The results suggest improvement in lesion estimation algorithm based on multi-frequency trans-admittance data.

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References

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