Biomedical subjects
Publications and source records attributed to C S Koukourlis.
A 32-electrode data collection system for Electrical Impedance Tomography (EIT) will be presented. In this system, the demodulator is a multiplexed sample and hold (S&H) circuit followed by a voltage difference stage. This configuration provides high CMRR due to the low (almost DC) operating frequency of the signals the difference stage is required to process.
A differential synchronous demodulator developed for electrical impedance tomography applications is presented. The demodulator proves to have high CMRR due to its architecture.
The performance of a differential synchronous demodulator is presented. This demodulator is part of an electrical impedance tomography system developed by our group. In addition a technique for common-mode correction instead of common-mode feedback is proposed. A series of measurements as a function of the common-mode signal is given.
A modified perturbation method (MPM) arising from the replacement of the sensitivity matrix by the Jacobian matrix is presented. Our results have been made using an array processor board with four T-800 INMOS transputers. The numerical algorithm has been matched to the new system and the procedure reached a minimum 50 times faster than for a single PC/AT with mathematical co-processor. Several phantoms have been reconstructed. From the results one can see the applicability of the MPM algorithm to complicated models.