US Patent 10159835 Detecting cutaneous electrode peeling using electrode-skin impedance

Apparatus for transcutaneous electrical nerve stimulation in a user, the apparatus comprising:stimulation means for electrically stimulating at least one nerve;an electrode array connectable to said stimulation means, said electrode array comprising a plurality of electrodes for electrical stimulation of the at least one nerve, said electrodes having a pre-formed geometry and known electrode-skin contact area size when in complete contact with the user's skin;monitoring means electrically connected to said stimulation means for monitoring the impedance of the electrical stimulation through said electrode array; andanalysis means for analyzing said impedance to estimate a change in the electrode-skin contact area.