Publications by authors named "N Polydorides"
The practical implementation of continuous monitoring of stroke patients by Electrical Impedance Tomography (EIT) is addressed. In a previous paper, we have demonstrated EIT sensitivity to cerebral hemodynamics, using scalp-mounted electrodes, very low-noise measurements, and a novel image reconstruction method. In the present paper, we investigate the potential to adapt that system for clinical application, by using 50% fewer electrodes and by incorporating into the measurement protocol an additional high-frequency measurement to provide an effective reference.
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- Researchers have successfully applied chemical species tomography (CST) to image the exhaust plume of gas turbines used in commercial aircraft, focusing on a specific near-infrared absorbing species.
- The study employs advanced tunable diode laser spectroscopy to measure absorption spectra, capturing data across various thrust levels and utilizing multiple data inversion techniques for image reconstruction.
- Notably, the images reveal a consistent ring structure of high concentration in the exhaust, indicating promising applications for CST in advancing turbine combustion, engine development, and fuel research.
An Electrical Impedance Tomography (EIT) system has been developed for dynamic three-dimensional imaging of changes in conductivity distribution in the human head, using scalp-mounted electrodes. We attribute these images to changes in cerebral perfusion. At 100 frames per second (fps), voltage measurement is achieved with full-scale signal-to-noise ratio of 105 dB and common-mode rejection ratio > 90 dB.
View Article and Find Full Text PDFObjective: We propose a numerical framework to simulate the Lorentz force electrical impedance tomography (LFEIT) measurements on accurate electrode models and an image reconstruction scheme for which data on two pairs of electrodes are sufficient.
Approach: The adopted finite element-based complete electrode model encompasses the electrode's geometry and contact impedance, accounting for the power losses at the contact interface. For image reconstruction, we suggest an approach based on a modified J-substitution algorithm that requires LFEIT and impedance measurements on two pairs of sensors, essentially necessitating no more than three boundary electrodes.