Ray, Not knowing if your title for definition is of your own making or from another source, I will assume it is from another source/document and that your are doing this for a wider reading rather than an in-house document. The reason being that I assume that the title has been created out of the need to differentiate when writing your doc. between the equipment under the jurisdiction of the 'Power Boys' (Heavy (Hospital) engineers) and that of us, the (electronics) Bio-Boyos! (light engineering).
In the past we were involved mainly with the 'lighter engineering' side of the equipment, such things as we still do as the 'bread and butter' work, fairly portable 'plug into the wall', mains/battery monitors, defibs pumps etc.etc. The dilemma as I see it in your request is that if you are not doing it solely as an in-house document, then one has to accommodate a big variation in the remit of one hospital to another 'world-wide.' I say this because many hospitals that we (the bio-eng)are working in, such as here in the Near and Middle-East for example, may well have been set up on a different basis than the average Med-Phys/Hospital Engineering department in England. The simple reason being that the demands put upon the individual hospitals during their evolution, and perhaps not having had a specific remit when opened, have created their own variations on what is and what is not considered acceptable for them to maintain and repair under the Bio-eng.
Our hospital for example, which has always closely allied itself to European standards, takes on the following equipment: Pathology Lab (clinical analysis), Dental, Linear Accelerators (Therapy treatment), Gamma Cameras to name but a few of the larger systems that the Bio-engineer is expected to service regularly. X-Ray / CT / MRI departments, 'Historically' not always under Bio-eng, may well feature in the remit of the future as it was only because the Med-Phys of the early days did not take this area on that it still is 'shied-away from' in some hospitals. But there is absolutely no reason for the Bio-engineers not to take the equipment on for servicing. The reason for accentuating this point is that the above equipments are not 'portable' but hard-wired. They would still come under the Bio-engineer and not the hospital engineer as they still have a definite 'clinical' connection.
Try this for a definition:
Electro(-bio, if you must) - medical equipment
Electrical equipment that is used in the - assessment by Analysis, Diagnosis, Treatment and Therapy, and the Monitoring, of a patient's clinical condition.
I personally do not think that the mention of how or where the power is derived is of significance. The point that 'Physics' in particular would accentuate would be the 'Clinical' connection. (I hear voices from our Web-site saying "what has Physics got to do with our work! - Yes what have they got to do with our work!!)
Nick