Suchergebnisse

Ergebnisse 41 - 50 von 57 :

Alle zurücksetzen
A short tutorial contribution to impedance and AC-electrokinetic characterization and manipulation of cells and media: Are electric methods more versatile than acoustic and laser methods?

, Shirley SG, Schnelle T, Fuhr G. Dielectrophoretic sorting of particles and cells in a microsystem. Anal. Chem. 1998, 70: 1909-1915. http://dx.doi.org/10.1021/ac971063b 10.1021/ac971063b Fiedler S Shirley SG Schnelle T Fuhr G Dielectrophoretic sorting of particles and cells in a microsystem Anal. Chem 1998 70 1909 – 1915 http://dx.doi.org/10.1021/ac971063b Foster KR, Schwan HP. 1996, Dielectric properties of tissues. Handbook of biological effects of electromagnetic fields. Polk C, Postow E (Eds.) CRC Press Inc., Boca Raton, FL. 25

Open access
Electrodermal activity responses for quantitative assessment of felt pain

hydration of the skin. In addition, they are better suited than wet gel electrodes for EDA measurements [ 22 , 23 ], and hence are crucial to obtain accurate results of EDA measurements. Electrodes were placed on the preferred arm of the participants. The M electrode was placed on the hypothenar site of the palm, the R electrode was placed on the apex of the elbow, which is an electrodermally inactive area as recommended [ 24 ], and finally the C electrode was placed on the underarm between M and R. Although abrasion [ 25 ] and skin drilling [ 26 ] were recommended as a

Open access
Electrical characterization of bolus material as phantom for use in electrical impedance and computed tomography fusion imaging

in radiation therapy were considered in the present study. The first sample, Sample 1, was the commercially available material Superflab made of 100% Akton® viscoelastic polymer; it is a low cost, well conforming material with a tissue equivalent dose absorption properties and density of 1.03 g/cc. The second sample, Sample 2, was an in-house developed material Gelatin Bolus made of gelatin (Benson Foods Ltd., Gelatine 175 Bloom). The gelatin is manufactured using pig skin and has 2% sodium by weight. Ten sub-samples of each sample were used for cross validation of

Open access
Extracting parasite effects of electrical bioimpedance measurements

.58 0.45 0.40 2.87 2.66 f R [Hz] NA 9.60 25.00 22.80 0.34 1.03 2.50 2.02 RMSRE 0.80 0.15 0.15 0.18 The objective of using electrical circuits were to reproduce the increase of impedance magnitude at increasing frequency, and then to extract R1 , L, C2, which were calculated from the fitted data. Standard deviations values are calculated in comparison to the measured ones. Furthermore, the Cole parameters (R 0 , R ∞ , F c and α) are calculated, either for the measured or calculated ones (R 1 , R 2 , R 3 , C 1 , C 2 and

Open access
Dielectrical properties of living epidermis and dermis in the frequency range from 1 kHz to 1 MHz

OCT [16] 65.1±8.9 8 31 - 37 OCT [17] SC (μm) 12.9±3.8 6 25 - 31 TEWL/Stripping [18] 12.3±3.6 6 33.2±3.1 TEWL/Stripping [19] 9.58±0.8 10 23 - 47 Reflectance CM [12] 10.4±3.2 13 18 - 25 CLSM [20] 22.6±4.33 14 23 - 49 CRS [21] 18±3.9 14 28 - 50 CRS [22] 10.4±0.9 9 23 - 55 OCT [22] 13.07±2.12 19 20 - 29 OCT [16] 18±2 2 23 - 25 CRS [23] DE (mm) 1.02±0.10 44 21 - 30 US 20MHz B scanner [24] 1

Open access
Modeling and Simulation of Equivalent Circuits in Description of Biological Systems - A Fractional Calculus Approach

interest only to mathematicians. On the other hand, many physical phenomena have "intrinsic" fractional order descriptions and so FC is necessary in order to explain them. In many applications FC provides more accurate models of the physical systems than ordinary calculus does. Because of its success in description of anomalous diffusion [ 16 , 17 , 18 ], non-integer order calculus both in one and multidimensional space, has become an important tool in many areas of physics, mechanics, engineering, and bioengineering [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26

Open access
Applications of bioimpedance measurement techniques in tissue engineering

-invasive Characterization of the Osteogenic Differentiation of hMSCs in 3D by Impedance Spectroscopy Dossel O Schlegel WC World Congress on Medical Physics and Biomedical Engineering, Vol 25, Pt 10: Biomaterials, Cellular and Tissue Engineering, Artificial Organs. IFMBE Proceedings. 25 New York Springer; 2009 81 84 https://doi.org/10.1007/978-3-642-03900-3_24 115 Yuste Y, Serrano, J., Olmo, A., Maldonado-Jacobi, A., Pérez, P., Huertas, G., Pereira, S., Portilla, F. and Yúfera, A., editor Monitoring Muscle Stem Cell Cultures with Impedance Spectroscopy. In

Open access
Electrical Impedance Spectroscopic Studies on Broiler Chicken Tissue Suitable for the Development of Practical Phantoms in Multifrequency EIT

in several aspects. Saline or any other salt solutions are purely resistive materials and hence the multifrequency EIT systems [ 1 , 22 , 23 , 24 ] cannot be studied properly with saline phantoms because the responses of the purely resistive materials do not change over frequency. On the other hand, electrical impedance of biological materials is a complex quantity [ 25 , 26 ] which is a function of tissue composition as well as the frequency of the applied ac signal [ 27 ]. The Protein-Lipid-Protein structure [ 28 ] of the membrane of a biological cell gives a

Open access
Testing miniaturized electrodes for impedance measurements within the β-dispersion – a practical approach

miniaturized electrodes. Today, almost any electrode shape and size even down to molecular level are feasible [ 25 ; 26 ]. Based on theoretical prediction, like FEM (finite element method), most researchers are today sure about the behavior of the electrode systems in use [ 27 ]. Problems are not always obvious. For instance, the simulation of the field distribution at equally shaped electrodes but with different size yields the same pictures. But calculating the geometry factor d/A (distance / surface area) for a simple electrode geometry reveals marked differences. For

Open access
Statistical methods for bioimpedance analysis

the whole population. In order to make a general conclusion about the population, we need to show that the effect that we observed was not likely due to chance from random variation in our sample. If we choose too few units, we may end up with an inconclusive result and a worthless study, and if we choose too many, we are wasting resources (e.g. sacrificing more animals than needed). Hence, sample size consideration is of ethical relevance [ 2 ]. In hypothesis testing, we want to reduce the chances of two types of errors: incorrectly rejecting a true null

Open access