Impedance mammograph 3D phantom studies

The results obtained using the Technical University of Gdansk Electroimpedance Mammograph (TUGEM) of a 3D phantom study are presented. The TUGEM system is briefly described. The hardware contains the measurement head and DSP-based identification modules controlled by a PC computer. A specially developed reconstruction algorithm, Regulated Correction Frequency Algebraic Reconstruction Technique (RCFART), is used to obtain 3D images. To visualize results, the Advance Visualization System (AVS) is used. It allows a powerful image processing on a fast workstation or on a high-performance computer. Results of three types of 3D conductivity perturbations used in the study (aluminum, Plexiglas, and cucumber) are shown. The relative volumes of perturbations less than 2% of the measurement chamber are easily evidenced.

Cell for measurements of biological tissue complex conductivity

The construction of the cell for measurement of complex electric conductivity is described. Two-chamber and four-electrode system with temperature stabilisation is developed. Guarding chamber and electrodes are used to minimise the leakage of current from the measurement chamber. The cell construction is examined by use of Finite Element Method. The model of the measurement cell is examined in order to improve the accuracy of measurements. The calibration procedure based on measurement of reference materials is presented. The frequency range of the cell is extended to 10 MHz with acceptable level of error. The examples of results from measurement breast normal and cancerous tissues are presented.