Don't the EBME Department want to look after your equipment, then? But if you have large labs, it might be worthwhile having your own maintenance technician if you can justify such a position.
In places I have worked (mainly overseas) I (we) always included the laboratories within our remit (as well as most other technical stuff within the hospital(s)). In the larger hospitals we generally had a "lab equipment specialist" on the team.
In fact I used to enjoy working in the labs myself ... they offered a bit of respite one or two steps back from any patient environment ... as well as presenting a lot of interesting kit (not to mention clued-up people). The labs always formed the largest department by numbers of items.
What happens about the other bits of "lab equipment" that may be scattered about the hospital? Things like the Blood Gas Analyzer often hidden away in the ICU, for instance? Do the biomeds take care of stuff like that?
But annual PM ... who has been doing it? What actually gets done? What procedures are being followed?
Another thing that comes to mind is that some of the specialised stuff is (was) often covered by service contracts with outside suppliers. What do they say about 61010, I wonder?
Lastly, remember that documentation (record keeping) is one of the key factors in equipment management. And one of the most tangible benefits of following a PM schedule (but one that is often forgotten) is that it brings the technician into contact with each item of equipment on a regular basis ... a "stitch in time" and good stuff like that.