Using electrical impedance tomography in following up skin conductivity change for different sonophoresis conditions

Abstract

Sonophoresis is the using of ultrasound waves to increase the entrancement of genes and drugs surpassing the skin barrier. Many mechanisms have been described to illustrate the sonophoresis mode of action; some describe changes in skin resistance during sonophoresis. Electrical impedance tomography (EIT) technique uses voltage measurement through a group of electrodes and reconstructs the data to a conductivity picture. The aim of this work is to evaluate the possibility of using EIT in order to detect changes in mice skin conductivity under pulsed ultrasound waves with powers of 1 and 3 W/cm2 and times of exposure of 2, 4, and 6 min. EIT system was designed and performed locally. The mice skin was obtained from ten albino mice. Immediately after the skin part was exposed to certain sonophoretic condition, its complex biological impedance was measured using the EIT device. The resultant pictures then were analysed using special software. The results indicate that EIT can be used as a good technique for skin conductivity scan. The data analysis shows that as the ultrasound power increases, the skin conductivity increases. However, there is no significant decrease in skin impedance with time in the same ultrasound power at the time range used. Key words: Electrical impedance tomography (EIT), sonophoresis, skin conductivity.