Current Source Design for Electrical Bioimpedance Spectroscopy

2008 ◽  
pp. 359-367 ◽  
Author(s):  
Fernando Seoane ◽  
Ramón Bragos ◽  
Kaj Lindecrantz ◽  
Pere Riu
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Biological Tissue ◽  
Electrical Impedance ◽  
Current Source ◽  
Electrical Impedance Spectroscopy ◽  
Bioimpedance Spectroscopy ◽  
Electrical Bioimpedance ◽  
Electronic Instrumentation ◽  
Passive Electrical Properties

The passive electrical properties of biological tissue have been studied since the 1920s, and with time, the use of Electrical Bioimpedance (EBI) in medicine has successfully spread (Schwan, 1999). Since the electrical properties of tissue are frequency-dependent (Schwan, 1957), observations of the bioimpedance spectrum have created the discipline of Electrical Impedance Spectroscopy (EIS), a discipline that has experienced a development closely related to the progress of electronic instrumentation and the dissemination of EBI technology through medicine.

scholarly journals Assessing ischemic injury in human intestine ex vivo with electrical impedance spectroscopy

2021 ◽  
Vol 12 (1) ◽  
pp. 82-88
Author(s):  
Jie Hou ◽  
Runar Strand-Amundsen ◽  
Stina Hødnebø ◽  
Tor Inge Tønnessen ◽  
Jan Olav Høgetveit
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Electrical Impedance ◽  
Electrical Impedance Spectroscopy ◽  
Time Interval ◽  
Human Intestine ◽  
Impedance Measurements ◽  
Intestinal Segments ◽  
Small Intestinal ◽  
Passive Electrical Properties

Abstract Electrical impedance spectroscopy is a well-established tool for monitoring changes in the electrical properties of tissue. Most tissue and organ types have been investigated in various studies. As for the small intestine, there are several published studies conducted on pig and rat models. This study investigates the changes in passive electrical properties of the complete wall of the human intestine non-invasively during ischemia. We aim to use the passive electrical properties to assess intestinal viability. The bioimpedance measurements were performed using a two-electrode set-up with a Solartron 1260 Impedance/gain-phase analyser. The small intestinal samples were resected from patients who underwent pancreaticoduodenectomy. Impedance measurements were conducted following resection by placing the electrodes on the surface of the intestine. A voltage was applied across the intestinal sample and the measured electrical impedance was obtained in the ZPlot software. Impedance data were further fitted into a Cole model to obtain the Cole parameters. The Py value was calculated from the extracted Cole parameters and used to assess the cell membrane integrity, thus evaluate the intestinal viability. Eight small intestinal segments from different patients were used in this study and impedance measurements were performed once an hour for a ten-hour period. One hour after resection, the impedance decreased, then increased the next two hours, before decreasing until the end of the experiment. For all the intestinal segments, the Py values first increased and reached a plateau which lasted for 1 - 2 hours, before it decreased irreversibly. The time interval where Py value reached the maximum is consistent with reported viable/non-viable limits from histological analysis.

scholarly journals Electrical Impedance Spectroscopy as Electrical Biopsy for Monitoring Radiation Sequelae of Intestine in Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pei-Ju Chao ◽  
Eng-Yen Huang ◽  
Kuo-Sheng Cheng ◽  
Yu-Jie Huang
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Integrated Circuits ◽  
Electrical Impedance ◽  
Roc Analysis ◽  
Electrical Impedance Spectroscopy ◽  
Electrical Characteristics ◽  
Injury Score ◽  
Histological Changes ◽  
Radiation Sequelae

Electrical impedance is one of the most frequently used parameters for characterizing material properties. The resistive and capacitive characteristics of tissue may be revealed by electrical impedance spectroscopy (EIS) as electrical biopsy. This technique could be used to monitor the sequelae after irradiation. In this study, rat intestinal tissues after irradiation were assessed by EIS system based on commercially available integrated circuits. The EIS results were fitted to a resistor-capacitor circuit model to determine the electrical properties of the tissue. The variations in the electrical characteristics of the tissue were compared to radiation injury score (RIS) by morphological and histological findings. The electrical properties, based on receiver operation curve (ROC) analysis, strongly reflected the histological changes with excellent diagnosis performance. The results of this study suggest that electrical biopsy reflects histological changes after irradiation. This approach may significantly augment the evaluation of tissue after irradiation. It could provide rapid results for decision making in monitoring radiation sequelae prospectively.

scholarly journals Effects of Lead Exposure on Blood Electrical Impedance Spectroscopy of Mice

2021 ◽  
Author(s):  
Binying Yang ◽  
Jia Xu ◽  
Shao Hu ◽  
Boning You ◽  
Qing Ma
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Lead Exposure ◽  
Electrical Impedance ◽  
Equivalent Circuit Model ◽  
Impedance Spectrum ◽  
Nyquist Plot ◽  
Electrical Impedance Spectroscopy ◽  
Impedance Method ◽  
Range Data

Abstract Background: Lead is a nonessential heavy metal, which can inhibit heme synthesis and has significant cytotoxic effects. Nevertheless, its effect on the electrical properties of red blood cells (RBCs) remains unclear. Consequently, this study aimed to investigate the electrical properties and the electrophysiological mechanism of lead exposure in mouse blood using Electrical Impedance Spectroscopy (EIS). Methods: AC impedance method was used to measure the electrical impedance of healthy and lead exposure blood of mice in 0.01-100 MHz frequency range. Data characteristic of the impedance spectrum, Bodes plot, Nyquist plot and Nichols plot, and three elements equivalent circuit model were used to explicitly analyze the differences in amplitude-frequency, phase-frequency, and the frequency characteristic of blood in electrical impedance properties. Results: Compared with the healthy blood in control mice, the changes in blood exposed to lead was as follows: (I) the hematocrit decreased; (II) the amplitude-frequency and phase-frequency characteristics of electrical impedance decreased; (III) the characteristic frequencies ( f 0 ) were significantly increased; (IV) the electrical impedance of plasma, erythrocyte membrane, and hemoglobin decreased, while the conductivity increased. Conclusion: Therefore, EIS can be used as an effective method to monitor blood and RBCs abnormalities caused by lead-exposure.

scholarly journals Experimental Study of Electrical Properties of Pharmaceutical Materials by Electrical Impedance Spectroscopy

2020 ◽  
Vol 10 (18) ◽  
pp. 6576
Author(s):  
Manuel Vázquez-Nambo ◽  
José-Antonio Gutiérrez-Gnecchi ◽  
Enrique Reyes-Archundia ◽  
Wuqiang Yang ◽  
Marco-A. Rodriguez-Frias ◽  
...  
Keyword(s):  
System Identification ◽  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Electrical Impedance ◽  
Wide Frequency Range ◽  
Electrical Impedance Spectroscopy ◽  
Frequency Range ◽  
Pharmaceutical Materials ◽  
Identification Techniques

The physicochemical characterization of pharmaceutical materials is essential for drug discovery, development and evaluation, and for understanding and predicting their interaction with physiological systems. Amongst many measurement techniques for spectroscopic characterization of pharmaceutical materials, Electrical Impedance Spectroscopy (EIS) is powerful as it can be used to model the electrical properties of pure substances and compounds in correlation with specific chemical composition. In particular, the accurate measurement of specific properties of drugs is important for evaluating physiological interaction. The electrochemical modelling of compounds is usually carried out using spectral impedance data over a wide frequency range, to fit a predetermined model of an equivalent electrochemical cell. This paper presents experimental results by EIS analysis of four drug formulations (trimethoprim/sulfamethoxazole C14H18N4O3-C10H11N3O3, ambroxol C13H18Br2N2O.HCl, metamizole sodium C13H16N3NaO4S, and ranitidine C13H22N4O3S.HCl). A wide frequency range from 20 Hz to 30 MHz is used to evaluate system identification techniques using EIS data and to obtain process models. The results suggest that arrays of linear R-C models derived using system identification techniques in the frequency domain can be used to identify different compounds.

scholarly journals Temperature Dependent Electrical Properties and Catalytic Activities ofLa2O3–CO2–H2OPhase System

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Bahcine Bakiz ◽  
Frédéric Guinneton ◽  
Madjid Arab ◽  
Sylvie Villain ◽  
Abdeljalil Benlhachemi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Decomposition ◽  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Electrical Impedance ◽  
Catalytic Properties ◽  
Electrical Impedance Spectroscopy ◽  
Temperature Dependent ◽  
Catalytic Activities ◽  
Coprecipitation Route

We present a study of electrical properties and catalytic activities of materials belonging to the hydrated carbonated systemLa2O3–CO2–H2O. The polycrystalline hydroxycarbonate, dioxycarbonate, and oxide are prepared via a coprecipitation route followed by heat treatment. The electrical conduction of the phases obtained by thermal decomposition fromLaOHCO3,H2Ois analyzed by electrical impedance spectroscopy, from25°Cto950°C, under air. The catalytic properties ofLaOHCO3,La2O2CO3andLa2O3polycrystalline phases are studied by FTIR spectroscopy, in presence of gas mixtures CO-air andCH4-air, at temperatures ranging between100°Cto525°C. The three materials behave differently in presence of CO orCH4gases.

Sign in / Sign up

Export Citation Format

Share Document