Generation of Multiphase Pulsed Voltages for Transdermal Drug Delivery

This paper first reviews the mechanism of transdermal drug delivery (TDD) and then presents the method for generating multiphase pulsed voltages (MPPVs) for TDD applications. In TDD applications, it offers many potential advantages over conventional methods, such as oral and injection treatments, and it avoids drug degradation through the gastrointestinal tract and liver. Due to the energy stored in an equivalent capacitor of human skin which is about 30% of the total energy consumption, a full-bridge type of converter is designed to recover this energy, and additionally, it is equipped with a soft-switching cell to achieve a zero-voltage switching or a zero-current switching, improving the efficiency of about 20%. The overall system needs only a set of soft-switching cells to achieve a soft-switching feature even though it can generate sets of pulsed voltages, reducing size and cost significantly. Moreover, the MPPVs are introduced to further improve the effectiveness of drug delivery. Experimental results from the TDD application with a 150-V output voltage and a 110-W peak power have demonstrated the feasibility of the proposed generator.