An 87mA·min iontophoresis controller IC with dual-mode impedance sensor for patch-type transdermal drug delivery system

In this paper, we present an iontophoresis controller IC with real-time monitoring of total injected charge quantity and skin condition. The proposed IC contains 32-level programmable current stimulator, a temperature sensor and a dual impedance sensor to monitor skin temperature, contact and tissue impedances. The measured temperature and impedances, related with the skin condition, are used for adaptive charge injection by modifying the current stimulation levels through the real-time feedback path. An implemented fabric patch type drug delivery system provides up to 87mA-min dosage larger than the dosage range (80mA-min) of commercial iontophoresis patches [4].