Modeling Stratum Corneum Swelling for the Optimization of Electrode-Based Skin Hydration Sensors

We present a novel computational model of the human skin designed to investigate dielectric spectroscopy electrodes for stratum corneum hydration monitoring. The multilayer skin model allows for the swelling of the stratum corneum, as well as the variations of the dielectric properties under several hydration levels. According to the results, the stratum corneum thickness variations should not be neglected. For high hydration levels, swelling reduces the skin capacitance in comparison to a fixed stratum corneum thickness model. In addition, different fringing-field electrodes are evaluated in terms of sensitivity to the stratum corneum hydration level. As expected, both conductance and capacitance types of electrodes are influenced by the electrode geometry and dimension. However, the sensitivity of the conductance electrodes is more affected by dimension changes than the capacitance electrode leading to potential design optimization.

Green tea moisturizer improves skin hydration in elderly

BACKGROUND<br />Dry skin is a major skin health problem in elderly. Green tea, which has an antioxidant effect, has recently been used as an active ingredient in moisturizing creams; yet the effect has not been well studied. This study compares the skin hydration effect of green tea and vitamin E moisturizer among elderly.<br /><br />METHODS<br />This quasi-experimental study involved 60 elderly living in Tresna Werda Budi Mulia 4 Social Institution, Jakarta. Using the Runve HL 611 skin analyzer, skin capacitance was measured prior to experiment and every following week during the 5-week application of green tea and vitamin E skin moisturizer on both forearms. The consecutive measurement data was analyzed using Generalized Estimating Equation to compare the relative changes in skin hydration between the two moisturizer groups over 5 weeks of intervention. <br /><br />RESULTS<br />The green tea moisturizer showed more significant increases in skin hydration level than the vitamin E moisturizer at all measurement sites on right arm and proximal left arm (p= 0.021), and medial and distal left arm (p= 0.034). Skin hydration levels significantly changed over time at proximal (p=0.021), medial (p=0.006) and distal (p=0.006) right arm, and medial left arm (p=0.021). A parallel trend of skin hydration improvements for both moisturizer groups indicated no correlation between the moisturizer type and the duration of usage (p &gt;0.05) in all measurement locations. No side effects were observed during application period in both groups.<br /><br />CONCLUSION<br />Routine use of moisturizer containing green tea may improve skin hydration in elderly.

The Weather-Beaten Dorsal Hand Clinical Rating, Shadow Casting Optical Profilometry, and Skin Capacitance Mapping

Laypeople commonly perceive some skin xerosis and withering (roughness) changes during winter on some parts of the body, particularly on the dorsal hands. The aim of the study was to assess the withered skin surface changes occurring during the four seasons. A total of 47 menopausal women completed the study. A group of 31 volunteers were on hormone replacement therapy (HRT) and 16 were out of HRT. Skin xerosis and scaliness were rated clinically. In addition, skin whitening was assessed by computerized shadow casting optical profilometry and by skin capacitance mapping. The volunteers were not using topical creams and over-the-counter products on their hands. Marked changes, recorded over the successive seasons, corresponded to patchy heterogeneous stratum corneum hydration and heterogeneous skin surface roughness changing over seasons; they likely resulted from changes in the environmental temperature and atmosphere moisture. The severity of the changes revealed by clinical inspection was not supported by similar directions of fluctuations in the instrumental assessments. This seemingly contradiction was in fact due to different levels of scale observation. The clinical centimetric scale and the instrumental inframillimetric scale possibly provide distinct aspects of a given biological impact.