Showing papers by "Tushar Kanti Bera published in 2019"
08 Aug 2019
TL;DR: Calibration studies show that LEBISDI not only interpreted the simulated and circuit-element data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells.
Abstract: Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing data-analyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance data for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies, electronic circuit element combinations as well as various biological tissues. We analyze the Nyquist plots obtained from the electrical impedance spectroscopy (EIS) measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI accurately interpreted simulated and circuit-element data. Furthermore, results obtained from biological tissues show that LEBISDI successfully interpreted bioimpedance data and estimates of capacitance and resistance data. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue impedance analysis for electrical impedance-based biopsy or cancer diagnosis.
23 citations
01 Oct 2019
TL;DR: This specific study aimed to determine the sensitivity and resolution of an electrically active human brain phantom when transmitting ultrasound through a human cadaveric skull and recording electrical activity on the skull.
Abstract: A broad spectrum of brain disorders—from epilepsy to depression – are characterized by abnormal electrical conduction. Often, electroencephalography (EEG) is incapable of recording the complex dynamics behind these disorders due to poor spatial resolution. We are proposing transcranial acoustoelectric brain imaging (tABI) to overcome these limitations. tABI may be able to accurately resolve deep neuronal currents with high spatial resolution ( 50 mm below the phantom surface with an axial resolution of ~3mm at 0.6 MHz. Current detection limits through the skull at biologically safe US intensities were <500μA--within range of the strongest induced neuronal currents in the human brain. Noninvasive detection of weak neural currents (<0.1mA/cm2) like those simulated with the phantom in this study would open the possibility to 4D tABI as a revolutionary modality for accurate, high resolution mapping of electrical signals in the human brain.
6 citations