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08:12
Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Electrical conductivity imaging via contactless measurements: an experimental study.
Başak Ulker Karbeyaz1, Nevzat G Gençer
1Electrical and Electronics Engineering Department, Middle East Technical University, 06531 Balgat, Ankara, Turkey. basak_ulker@yahoo.com
IEEE Transactions on Medical Imaging
|July 9, 2003
Summary
A new contactless system images biological tissue conductivity using magnetic fields. This technology can distinguish conductivity variations and shows potential for clinical applications in medical imaging.
Area of Science:
- Biomedical Engineering
- Electrical Engineering
- Medical Imaging
Background:
- Accurate electrical conductivity imaging of biological tissues is crucial for diagnosing various medical conditions.
- Current methods for conductivity measurement often require direct contact, limiting their application in certain clinical scenarios.
- Non-contact methods offer a promising alternative for safer and more versatile tissue conductivity assessment.
Purpose of the Study:
- To develop and validate a novel data-acquisition system for contactless electrical conductivity imaging of biological tissues.
- To assess the system's performance in terms of linearity, sensitivity, signal-to-noise ratio, and thermal stability.
- To demonstrate the capability of the system to reconstruct conductivity images and distinguish conductivity variations in phantoms and biological tissues.
Main Methods:
- A PC-controlled lock-in amplifier system was employed for data acquisition.
- Magnetic excitation induced currents within biological tissues, and resulting magnetic fields were measured.
- A magnetically coupled differential coil system with specific transmitter and receiver coil parameters was utilized for scanning.
- The steepest-descent algorithm was implemented for conductivity image reconstruction.
Main Results:
- The system demonstrated a linearity of 7.2% full scale and a sensitivity of 21.47 mV/(S/m) at a 0.3 cm sensor-body distance.
- Detection of a conducting tube (0.2 S/m) was possible at a distance of 6 cm from the sensor.
- The system achieved a signal-to-noise ratio of 34 dB and thermal stability of 33.4 mV/°C.
- Reconstructed images successfully distinguished two tubes separated by 17 mm and accurately represented phantom conductivity distributions.
Conclusions:
- The developed contactless data-acquisition system effectively images electrical conductivity in biological tissues.
- The system exhibits sufficient sensitivity and resolution for distinguishing conductivity variations, showing promise for clinical use.
- This non-contact magnetic induction approach holds significant potential for advancing medical imaging and diagnostics.
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