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A sectorial sensitivity matrix using a K-means clustering algorithm has been proposed for electrical capacitance tomography (ECT) for accurate determination of permittivity distribution in the inclusion within the background area. The proposed sectorial sensitivity matrix clusters the pixel position of the inclusion area to minimize the soft field effect that leads to image artifacts and blurred images. The standard sensitivity matrix is nonlinear thus it is not easy to eliminate image artifacts due to the noise signal and nonlinear electric field propagation. The performance of the sectorial sensitivity matrix is evaluated through numerical simulation and experimental studies. From the results, the sectorial sensitivity matrix improves the reconstructed images with a 42.92% and 67.12% lower root mean square error RMSE, 1.66% and 16.16% higher correlation coefficient CC, and 21.37% lower image error IE values in the simulation and experimental studies respectively as compared to the standard sensitivity matrix. The sectorial sensitivity matrix has an advantage of high performance even when the signal to noise ratio in an ECT system is low. Under such conditions, the present normalization method is incapable of calculating the normalized capacitance of the inclusion due to the low ratio of permittivity of the inclusion to that of the background.

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Optimal serum protein concentrations are vital for normal body functioning. Affordable while accurate protein quantification methods with minimum processing requirements are needed for diagnosis of related diseases. The standard automated chemistry analyzer is limited by high installation and maintenance costs. This study proposes the use of electrical impedimetric spectroscopy (EIS) as an alternative to current methods. Its practical applicability was tested using albumin and γ‐globulin or their miscellanea in three different media; water, serum and tissue‐mimicking phantoms at 25 °C. Impedance measurements were taken between frequency f=0.10 MHz to 300 MHz by an impedance analyzer. A Cole‐Cole analysis was used to elucidate the stepwise variations in the dielectric parameters of the protein medium so as to obtain empirical dielectric parameter‐protein concentration relationships and their correlation coefficients R2. From the results, linear relationships between parameters and protein concentrations with high correlation coefficients over R2=0.90 were observed. Resistance to charge transfer Rct and characteristic frequency fc were significantly altered by changing protein concentrations as compared to bulk solution resistance Rs, relaxation time constant τ and shape factor α. The relationships developed would aid in monitoring changes in body fluid protein concentrations by EIS.