Circuits and Systems Group - Sensors & Instrumentation

Sensors & Instrumentation

Magnetic Sensors

Magnetic Sensor systems ASIC design and architectures development. Focused on Anisotropic Magneto-Resistance (AMR) elements with ultra-wide operational bandwidth. Signal conditioning and data acquisition integration to reduce sensor’s cost and physical size while achieving low noise, high resolution, fast response, closed-loop operation. Applications include Biomedical, Navigation and field surveillance.

Relevant Publications

K. Papafotis, D. Nikitas, P.P. Sotiriadis, "Magnetic Field Sensors’ Calibration: Algorithms’ Overview and Comparison", Sensors 2021, 21, 5288.

N. Hadjigeorgiou, K. Asimakopoulos, K. Papafotis, P.P. Sotiriadis, "Vector Magnetic Field Sensors: Operating Principles, Calibration and Applications," IEEE Sensors Journal, vol. 21, no. 11, pp. 12531-12544, 1 June1, 2021.

P.P. Sotiriadis, K. Papafotis, "Accurate Analytical Accelerometer–Magnetometer Axes Alignment Guaranteeing Exact Orthogonality," IEEE Trans. on Instrumentation and Measurement, vol. 70, pp. 1-7, 2021.

K. Papafotis, P.P. Sotiriadis, "Multiple Accelerometers and Magnetometers Joint Calibration and Alignment”, IEEE Sensors Letters, Vol. 4, Issue 3, March 2020, pp. 2475-1472.

K. Papafotis, P.P. Sotiriadis, "Accelerometer and Magnetometer Joint Calibration and Axes Alignment", Technologies 2020, 8, 11. [Invited]

N. Hadjigeorgiou, K. Papafotis, P.P. Sotiriadis, "Exploring AMR Sensor's Performance Limits Using an Agile, High-Speed Set-Reset Pulse Generation Circuit", IEEE Trans. on Magnetics, vol. 56, no. 9, pp. 1-10, Sept. 2020.

N. Hadjigeorgiou, P.P. Sotiriadis, “Parasitic Capacitances, Inductive Coupling and High-Frequency Behavior of AMR Sensors”, IEEE Sensors Journal, vol. 20, no. 5, pp. 2339-2347, 1 March1, 2020.

K. Papafotis, P.P. Sotiriadis, "MAG.I.C.AL. – A Unified Methodology for Magnetic and Inertial Sensors Calibration and Alignment", IEEE Sensors Journal, vol. 19, no. 18, pp. 8241-8251, 15 Sept.15, 2019.

N. Hadjigeorgiou, E. Hristoforou, P. P. Sotiriadis, “Closed-Loop Current-Feedback, Signal-Chopped, Low Noise AMR Sensor With High Linearity”, ΙΕΕΕ International Conference on Modern Circuits and Systems Technologies, 2017.

N. Hadjigeorgiou, S.Angelopoulos, E. Hristoforou, P. P. Sotiriadis, “Flux-Gate Vs. AMR Magnetic Sensors Characteristics in Closed-Loop Operation”, International Conference on Magnetism and Magnetic Materials, 2017.

N. Hadjigeorgiou, A. C. Tsalikidou, E. Hristoforou, P. P. Sotiriadis, “Highly Linear and Low Noise AMR Sensor Using Closed Loop and Signal-Chopped Architecture "”, Internatinal Conference on Magnetism and Magnetic

Inertial Navigation Systems

Precise Navigation Systems based on low-cost inertial and magnetic field sensors. Development of highly accurate, computationally efficient calibration techniques for inertial and magnetic field sensors. Data fusion algorithms for trajectory tracking and motion analysis.

Relevant Publications

K. Papafotis, D. Nikitas, P. P. Sotiriadis, "Improving Gyroscope’s Noise Performance Using Multiple Accelerometers in a Closed-Loop Configuration", IEEE Sensors Journal, 2022, DOI: 10.1109/JSEN.2022.3207110.

P.P. Sotiriadis, K. Papafotis, "A Single-Step Method for Accelerometer and Magnetometer Axes Alignment", IEEE Trans. on Instrumentation and Measurement, vol. 70, pp. 1-7, 2021.

K. Papafotis, P.P. Sotiriadis, "A Fast and Accurate Accelerometer and Magnetometer Alignment Algorithm", IEEE Sensors Journal, vol. 20, no. 24, pp. 15061-15067, 15 Dec.15, 2020.

K. Papafotis, P.P. Sotiriadis, "Multiple Accelerometers and Magnetometers Joint Calibration and Alignment”, IEEE Sensors Letters, Vol. 4, Issue 3, March 2020, pp. 2475-1472.

K. Papafotis, P.P. Sotiriadis, "Accelerometer and Magnetometer Joint Calibration and Axes Alignment", Technologies 2020, 8, 11. [Invited]

K. Papafotis, P.P. Sotiriadis, "Exploring the Importance of Sensors' Calibration in Inertial Navigation Systems ", IEEE International Symposium on Circuits and Systems, Seville, Spain, 2020.

K. Papafotis, Paul P. Sotiriadis, "Computationally Efficient Calibration Algorithm for Three-Axis Accelerometer and Magnetometer", IEEE International Conference on Modern Circuits and Systems Technologies, Thessaloniki, Greece, 2019. [Best Paper Award]

Electrical Impedance Tomography

Electrical Impedance Tomography for biomedical applications. Mathematical imaging and algorithms for solving the forward and the inverse problem. Model development and simulation to analyze the effects of tissue conductivity changes in real-time imaging. Embedded circuit system design, optimization and implementation, ASIC design for the analog front-end.

Relevant Publications

Dimas, V. Alimisis, N. Uzunoglu, P. P. Sotiriadis, "A Point-Matching Method of Moment with Sparse Bayesian Learning Applied and Evaluated in Dynamic Lung Electrical Impedance Tomography", Bioengineering 2021, 8, 191.

C. Dimas, V. Alimisis, I. Georgakopoulos, N. Voudoukis, N. Uzunoglu, P.P. Sotiriadis, "Analysis, Simulation, and Development of a Low-Cost Fully Active-Electrode Bioimpedance Measurement Module", Technologies 2021, 9, 59.

C. Dimas, V. Alimisis, I. Georgakopoulos, N. Voudoukis, N. Uzunoglu, P.P. Sotiriadis, "Evaluation of Thoracic Equivalent Multiport Circuits Using an Electrical Impedance Tomography Hardware Simulation Interface", Technologies 2021, 9, 58.

V. Alimisis, C. Dimas, G. Pappas, P.P. Sotiriadis, "Analog Realization of Fractional-Order Skin-Electrode Model for Tetrapolar Bio-Impedance Measurements". Technologies 2020, 8, 61.

C. Dimas, N. Uzunoglu, P.P. Sotiriadis, "A parametric EIT system Spice simulation with phantom equivalent circuits”, Technologies 2020, 8, 13. [Invited]

C. Dimas, N. Uzunoglu, P. Sotiriadis, "Electrical Impedance Tomography Image Reconstruction: Impact of Hardware Noise and Errors", ΙΕΕΕ International Conference on Modern Circuits and Systems Technologies, Thessaloniki, Greece, 2019.

C. Dimas, N. Uzunoglu, P. Sotiriadis, “3D EIT Imaging with Green's functions”, 20th International Conference on Biomedical Applications of Electrical Impedance Tomography, London, 2019.

C. Dimas, N. Uzunoglou, P. Sotiriadis, "A Field Theory Approach in EIT with Green’s Functions", 19th International Conference on Biomedical Applications of Electrical Impedance Tomography, 2018.

C. Dimas, V. Alimisis, P.P. Sotiriadis, "SPICE and MATLAB simulation and evaluation of Electrical Impedance Tomography readout chain using phantom equivalents", European Conference on Circuit Theory and Design, Sofia, Bulgaria, 2020.

C. Dimas, K. Asimakopoulos, P.P. Sotiriadis, "A highly tunable dynamic thoracic model for Electrical Impedance Tomography", IEEE International Conference on BioInformatics And BioEngineering, USA, 2020.

Research Directions