Louis,
I would have thought so, but the manufacturer put it through as a conventional battery operated TENS device, and it was accepted as such.
Without people like us to monitor the equipment as it enters use, these anomalies would not be found.
We audit our equipment schedule annually, but it can never be up to date, because equipment comes and goes, with and without our knowledge. Staff have protocols, but don't always stick to them.
We do our pm's 6 monthly in every area, minors and majors. This gives us a chance see most of the equipment we are responsible for. (Even if we can't service it all) Visual inspections are an important part of the work we do and we find quite a few problems. (Cracked cases etc)