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http://dx.doi.org/10.9718/JBER.2007.28.1.084

320-Channel Multi-Frequency Trans-Admittance Scanner(TAS) for Anomaly Detection  

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)
Publication Information
Journal of Biomedical Engineering Research / v.28, no.1, 2007 , pp. 84-94 More about this Journal
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.
Keywords
multi-frequency; TAS (trans-admittance scanner); conductivity; permittivity; lesion estimation algorithm;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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