Abstract
Electrical impedance tomography (EIT) is a promising technique for imaging the conductivity distribution within the body from voltage surface measurements. The measuring precision is very important, where inaccuracies from the current source generate distortions in the images. These are particularly caused by stray capacitances which reduce the frequency response of the instrumentation. This paper investigates the performance of a bipolar current source attached to a multiplexer using an Automatic Gain Control (AGC) Amplifier circuit. Output current measurements were made in the frequency range 100 Hz to 1 MHz and also output impedance at 100 kHz, both with and without the AGC Amplifier circuit. The results showed a constant output current with a maximum error of ±2% when using the AGC Amplifier circuit whereas 300% not using it. Also, the output impedance was approximately 10.4 and 1.2 M? with and without using the AGC Amplifier circuit, respectively. It can be concluded that the AGC Amplifier circuit may increase significantly the precision of the current measurements and may improve the image quality in EIT systems.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
