I have seen them in a few trade shows. I think it is a variant of EMS device.
When in doubt, ask for the CLINICAL TRIALS and what they have in terms of outcome data. EMS does have some clinical evidence in wound healing and pain relief, although not convincingly so. I usually prescribe EMS for pain control, especially when DM patients don't get adequate pain relief from neuropathy with pharmaco-therapy, ie. Lyrica and cymbalta.
I see a lot of new dressings and devices in wound care conferences all the time, but I don't waste my time unless they can show me something substantial, not just "Dr. XYZ used it and he loves it."