We evaluated impedance pharyngography (IPG), a new method to assess swallowing function based on changes in the electrical impedance of the neck during swallowing. The electrical impedance of the neck, recorded by the 4-electrode method, changed with the equivalent crosssectional area of the route of the electric current due to reflex activities of related organs during swallowing. IPG waveforms accurately recorded the swallowing process, therefore. We recommend IPG for assessing swallowing function because we expect IPG to provide the following advantages over conventional diagnostic techniques: it is a quantitative method that allows for the objective assessment of swallowing function; it is a simple procedure that is convenient for the patient and could be used for screening; it is inexpensive and non-invasive, so could be performed repeatedly in situations such as rehabilitation; and it uses highly portable equipment suitable for community use.

We investigated the relationship between impedance parameters and skeletal muscle function in the lower extremities, as well as the effectiveness of impedance parameters in evaluating muscle quality. Lower extremity impedance of 19 healthy men (aged 23–31 years) measured using the direct segmental multi-frequency bioelectrical impedance analysis were arc-optimized using the Cole–Cole model, following which phase angle (PA), $${R}_{i}/{R}_{e}$$ R i / R e , and β were estimated. Skeletal muscle function was assessed by muscle thickness, muscle intensity, and isometric knee extension force (IKEF). IKEF was positively correlated with PA (r = 0.58, p < 0.01) and β (r = 0.34, p < 0.05) was negatively correlated with $${R}_{i}/{R}_{e}$$ R i / R e (r = − 0.43, p < 0.01). Stepwise multiple regression analysis results revealed that PA, β, and $${R}_{i}/{R}_{e}$$ R i / R e were correlated with IKEF independently of muscle thickness. This study suggests that arc-optimized impedance parameters are effective for evaluating muscle quality and prediction of muscle strength.

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Deterioration of skin barrier function causes symptoms such as allergies because it allows various chemical substances to enter the human body. Quantitative evaluation of the thickness and water content of the stratum corneum is useful as a measure of skin barrier function in elds such as dermatology, nursing science, and cosmetics development. The stratum corneum is responsible for most of the skin barrier function, and this function has conventionally been evaluated using transepidermal water loss (TEWL). In this paper, we propose a new model for estimation of TEWL from measurements of the thickness of the stratum corneum and water content of the surface of the stratum corneum, and discuss the results of the measurements. By measuring the thickness and water content of the stratum corneum using confocal laser microscopy and confocal Raman spectroscopy, respectively, and examining the relationship of these variables with TEWL, we established a new potential model for estimating TEWL from these two variables. The correlation coef cient of the validation data was 0.886 and the root mean squared error was 8.18 points. These ndings indicate the feasibility of qualitative evaluation of TEWL by measuring the thickness and water content of the stratum corneum.