Skin impedance implications of TENS function and the development of an improved stimulation waveform

A modified Transcutaneous Electric Nerve Stimulator (TENS) stimulation waveform is being used in an experimental prototype unit. The waveform varies from those generated in traditional TENS in shape and spectral content. A pilot study of skin impedance using TENS electrodes was performed. Impedance characteristic Bode plots were made of subjects with prepared and unprepared skin. Spectral magnitudes were then compared to the spectral energies of a traditional TENS device stimulation waveform and the prototype waveform. An effective power transfer ratio was calculated of the two waveforms and the prototype waveform showed a 80% effective power transfer increase over the traditional waveform. Insight has also been gained into how DC resistance measurements can be performed after epidermal electrical excitation