Not so much
mislaid I would say Neil, as
transient. Under the modern healthcare for the masses
paradigm we can expect more and more medical equipment to be travelling around with the patient, wherever s/he may roam. So why not think about a central NHS Agency tracking (that is, taking care of) all this stuff? In fact, why not doing just that for
all NHS equipment assets?
There is also an increasing amount of medical equipment "out there in the community". We also see "point of care" (as in,
at the ...) equipment that not so long ago would have been found only in hospital clinical labs, now becoming almost commonplace in patients' homes (nursing homes, and all the rest).
So yes, those responsible for supporting all this kit need to "think again", as it were, about (not only) tagging, but also how to maintain it all in general.
A lot of this kit is battery powered (or DC powered off a mains charger), so the traditional "electrical safety warrior" may need to think again as well (that is, but I digress ... there is more to PM that just a "Rigel* test")!
It's a whole new ball game, methinks. And, perhaps, a whole new market. It's just a thought ... but maybe the traditional hospital-based biomed department is rapidly becoming er, "yesterday's news"! EBME? Man, it's so
20th Century! 
But what about the idea of equipment that "reports back" (announces its presence), as it were. I guess, Neil, that you missed
this earlier
diatribe ... still very much "a work in progress" (
aka on the back-burner) I'm afraid.
And perhaps I had better mention straight off the bat ... when it comes to implementation (development, whatever) of the GLIB idea, I shall be looking for 50% (at least)!

*
Note: other medical equipment electrical safety testers may be available!