perceptivity and Z 0 is the starting offset (or bias) a given impedance is varying around. In relative perceptivity, the unit of impedance is taken out of the equation, and if the phenomena have no unit, the perceptivity is unit-less.
Finite Element Model Examples
Three examples are modelled in the Finite Element Model (FEM) tool COMSOL Multiphysics. For simplicity, the models are for stationary conditions. Only the three different material types shown in table 1 are used. The equations defining the model behavior is predefined in the COMSOL Multiphysics physics
Jakob Orschulik, Diana Pokee, Tobias Menden, Steffen Leonhardt and Marian Walter
regions than on the bottom regions. In total, however, even in the less focusing right top configuration the non-ventilated case is clearly visible. Even more, by combination of multiple measurements (for example top and bottom right), a more precise localization should be possible.
Discussion and Conclusion
Our results indicate that focused impedance measurements can be a useful tool to provide a three-dimensional, pulmonary monitoring of desired regions of interest. In simulations, it was possible to focus impedance measurements to specific regions of the lung
Transcranial electrical stimulation using weak current may be a promising tool to modulate cerebral activity in a noninvasive, and to some extent reversible, selective way [ 1 ]. Transcranial direct current stimulation (tDCS) is a useful noninvasive technique that imposes a weak direct electrical current (1-2 mA) to modulate the activity of neurons in the brain. The experiments suggested that electrodes placed on the head can produce noticeable neurological changes depending on the current direction [ 2 ]. The current results in an electric field
Souhir Chabchoub, Sofienne Mansouri and Ridha B. Salah
flow from the left ventricle into the left atrium [ 23 ]. MI is the most-frequent valvular heart disease in the world and it is constituted as the second most prevalent valve disease after aortic valve stenosis. The major complication of MI is heart failure, pulmonary hypertension, atrial fibrillation, and death [ 24 ]. There are several diagnostic tools in assessing Mitral Insufficiency such as the chest X-ray, the echocardiography, and catheterization. The most interesting diagnostic technique that can provide important information about MI is echo
Gy, 2-6 Gy, 6-10 Gy, and > 10 Gy. A tool to rapidly exclude those exposed to 6 Gy, for example, with a bioelectric measurement could save great deal of time and resources that are otherwise required in a radiation emergency response.
Common versus site-specific responses in vasculature
Prior work in radiation biology has shown that vascular barriers can be perturbed by irradiation and that this perturbation can be assessed by impedance methods [ 6 , 7 , 28 ]. The significant and unique finding of this paper, using an impedance method, is that a primary human
Martina Sammer, Bob Laarhoven, Ernest Mejias, Doekle Yntema, Elmar C. Fuchs, Gert Holler, Georg Brasseur and Ernst Lankmayr
bacteria and biofilm on double-layer capacitance during biofilm monitoring by electrochemical impedance spectroscopy Water Res 2011 45 15 4615 – 4622 http://dx.doi.org/10.1016/j.watres.2011.06.010
12 Heileman K, Daoud J, Tabrizian M. Dielectric spectroscopy as a viable biosensing tool for cell and tissue characterization and analysis. Biosens Bioelectron. 2013;49:348–359. http://dx.doi.org/10.1016/j.bios.2013.04.017 10.1016/j.bios.2013.04.017 23796534 Heileman K Daoud J Tabrizian M Dielectric spectroscopy as a viable biosensing tool for cell and
found in Yoglekar et al. [ 12 ].
Memristors and bioimpedance
Within the field of bioimpedance and bioelectricity the memristor may be a valuable tool for circuit modeling and fundamental physical insight. There are a many observed hysteretic, anomalous or nonlinear i-v characteristics in nature [ 13 , 14 , 15 ] that may potentially fit better in a memristive framework than in any other. Typically, as we have seen, memristive fingerprints are visible at systems where the scales of the characteristic electrical processes are small (for instance biological
Sepideh Mohammadi Moqadam, Parvind Kaur Grewal, Zahra Haeri, Paris Ann Ingledew, Kirpal Kohli and Farid Golnaraghi
An electrical Impedance based tool is designed and developed to aid physicians performing clinical exams focusing on cancer detection. Current research envisions improvement in sensor-based measurement technology to differentiate malignant and benign lesions in human subjects. The tool differentiates malignant anomalies from nonmalignant anomalies using Electrical Impedance Spectroscopy (EIS). This method exploits cancerous tissue behavior by using EIS technique to aid early detection of cancerous tissue.
The correlation between tissue electrical properties and tissue pathologies is identified by offering an analysis technique based on the Cole model. Additional classification and decision-making algorithm is further developed for cancer detection. This research suggests that the sensitivity of tumor detection will increase when supplementary information from EIS and built-in intelligence are provided to the physician.
becomes increasingly capable. This tutorial will show how to create such a model and how to perform a virtual experiment on it. The goal is to learn how to model an experiment in order to see what we really measure, and to gain insight in volume impedance measurements in general.
Specifically, this tutorial will take the reader trough the steps involved in making a model and do measurement simulations on it using software tools from Simpleware and COMSOL.
An overview of the tutorial steps are shown in figure 1 . It is possible to skip the first parts since
although some funny little distortion of the semicircle did show up – but was first disregarded as imperfections in the measurement system. When we realized the information we wanted was hiding in the almost drowned β dispersion, we tried simple indices and found that we could discriminate between different toxically elicited reactions using EIS, and correlate information in such spectra to the ”gold standard” histopathology, we thought: Wow, maybe EIS could work also in the clinic as a decision support tool for medical doctors.
We decided to go for skin cancer, and