A methodology for extracting the electrical properties of human skin.

A methodology to determine dielectrical properties of human skin is presented and analyzed. In short, it is based on a mathematical model that considers the local transport of charge in the various layers of the skin, which is coupled with impedance measurements of both stripped and intact skin, an automated code generator, and an optimization algorithm. New resistivity and permittivity values for the stratum corneum soaked with physiological saline solution for 1 min and the viable skin beneath are obtained and expressed as easily accessible functions.

Non-invasive bioimpedance of intact skin: mathematical modeling and experiments.

The functional integrity and pathology of the skin is reflected in its electrical impedance spectra. Non-invasive electrical impedance measurements of intact skin are dominated by the high impedic stratum corneum in low frequencies and with increasing frequency gradually comes to be dominated by viable skin. Models of this multi-layered organ can increase our understanding of the actual physical properties/dimensions and facilitate better diagnostics in certain applications.

Non-invasive and microinvasive electrical impedance spectra of skin cancer - a comparison between two techniques.

Background/purpose: Bio-electrical impedance spectra of skin cancer and other lesions can be assessed using both regular non-invasive probes and a novel type of microinvasive electrode system with a surface furnished with tiny spikes that penetrate stratum corneum. The aim of the study was to compare the accuracy of detection for various types of skin cancer using impedance spectra measured with these two different electrode systems in an objective way without optimising the power of discrimination.

Methods: Impedance spectra of 99 benign nevi, 28 basal cell carcinomas (BCC), and 13 malignant melanomas (MM) were measured using the two electrode systems.

Skin cancer identification using multifrequency electrical impedance--a potential screening tool.

Electrical bio-impedance can be used to assess skin cancers and other cutaneous lesions. The aim of this study was to distinguish skin cancer from benign nevi using multifrequency impedance spectra. Electrical impedance spectra of about 100 skin cancers and 511 benign nevi were measured.

Clinically normal atopic skin vs. non-atopic skin as seen through electrical impedance.

Background/aims: In an earlier study, we have shown that the electrical impedance (IMP) is dependent on the lipid content of the stratum corneum as studied by lipid extraction. Therefore, we now employ the IMP technique to compare the properties of clinically normal atopic skin with that of non-atopic skin. We looked at the same time at concomitant alterations in transepidermal water loss (TEWL) and skin moisture results.

Assessment of skin lesions and skin cancer using simple electrical impedance indices.

Background/aims: Purpose of this investigation was to assess benign pigmented cellular nevus (BEN), basal cell carcinoma (BCC), dermatofibroma (DER), dysplastic nevus (DYS), and seborrheic keratoses (SEB) using in vivo non- invasive electrical impedance technique.

Methods: Electrical impedance was measured at 258 BEN, 34 BCC, 17 DER, 35 DYS, and 26 SEB lesions. Controls were measured at healthy skin close to the lesions.

The effects of two sodium lauryl sulphate-containing toothpastes with and without betaine on human oral mucosa in vivo.

The aim was to compare the effects of two sodium lauryl sulphate (SLS)-containing toothpaste formulations with and without betaine on human oral mucosa in vivo. The results are compared with the effect of a dry mouth toothpaste without SLS. Twenty subjects participated in the double blind, crossover study.

The ability of betaine to reduce the irritating effects of detergents assessed visually, histologically and by bioengineering methods.

Background/aims: A novel approach for reducing the undesired irritating properties of detergents on skin might be offered by betaine, which is a natural product derived from the sugar beet. The aim of the study was to explore the ability of betaine to reduce the irritating effects of two surfactants, sodium lauryl sulphate (SLS) and cocoamidopropylbetaine (CAPB). For evaluation of changes in skin reactions visual scoring, electrical impedance, transepidermal water loss and histology were used.

The use of different concentrations of betaine as a reducing irritation agent in soaps monitored visually and non-invasively.

Background/aims: Products containing detergents can damage the skin and give rise to irritant contact dermatitis. Therefore, attempts have been made to find less irritating detergents as well as substances decreasing undesired side-effects of detergents, and a novel approach is offered by betaine. The aim of the study has been to determine the irritating properties of some liquid soaps for personal hygiene and to map the effect of different concentrations of betaine using electrical impedance, trans-epidermal water loss and visual inspection.

Betaine reduces the irritating effect of sodium lauryl sulfate on human oral mucosa in vivo.

Our aim was to evaluate whether betaine has a protective effect during exposure of the human oral mucosa in vivo to sodium lauryl sulfate (SLS) or cocoamidopropylbetaine (CAPB) as measured with a multifrequency electrical impedance spectrometer (EI). Both detergents were used at the concentration of 2.0% w/v with and without 4.

Variation of skin properties within human forearms demonstrated by non-invasive detection and multi-way analysis.

Background/aim: It is known that the properties of human skin vary locally. The purpose of this study was to investigate the properties of human volar forearms even further using advanced non-invasive techniques and numerical methods.

Methods: The skin properties of human volar forearms were investigated using measurements of trans epidermal water loss and multifrequency electrical impedance.

Electrical impedance measurements at different skin sites related to seasonal variations.

BACKGROUND/AIMS: In a previous study we mapped differences in electrical impedance between different anatomical locations related to age and sex. Now we employ the electrical impedance technique for studying the seasonal variations for the same skin sites. METHOD: The investigation was performed on 48 healthy volunteers divided into two groups on the basis of sex.