RESUMO
Objective To design the circuit used in drug-iontophoresis and interference electric current therapy,which is a multi-functional apparatus. Methods Controlled by singlechip,through the D/A conversion and the functional generator ICL8038,a variety of waveforms were generated. The digital potentiometer was used to amplitude modulation. After the power amplifier and isolation,the signal needed was output. Results It had multiple output channels which could be regulated and controlled independently and could produce a variety of waveforms with adjustable parameters. Conclusion The circuit can complete the drug-iontophoresis and interference electric current therapy,which has simple structure and is low cost and multi-functional. It provides a new type of circuit for the relevant instrument design.