I think John, Nick and Paul's suggestions are fine and cover a broadbase definition of electro-medical equipment.
May I offer a more cynical suggestion
Any device that has the ability to be dropped by a nurse, tinkered with by an O.D.P., blown up by a Therapist or pilfered by a Consultant and requires a continued service or calibration kit provided, at extortionate cost, by the supplier and can be maintained at great expense by the EBME Dept until the manufacturer either goes bust or refuses to supply any spare parts
