I've been asked to do plenty of work "at the sickbed" by clincians and Nurses however since the loss of "Crown Immunity" years ago and the fact that I'm not regulated, thus have little protection because I present a potential risk to the patient in this scenario, then this is much reduced - although, personally speaking, I'm happy to "advise" at the bedside if an operator is having difficulty, e.g. difficulty when monitoring a physiological parameter, due to faulty cables, etc.
I'm in clincial areas a lot of the time and so are my colleagues - providing advice and responding to issues concerning medical devices. We don't have to be "mopping patients brows" to be clinical - although I'm not particularly bothered what I'm called. I'm not keen on being called Bio-medical Engineer but my employer calls me that - I'm not actually an Engineer and not sure what Bio-Medical means.
Engineering departments do have a lot of input into the use of clinical devices that affect the level of patient care for example. Some get involved with adapting medical devices and systems, etc.
The term you used to define Clinical is "concerned with the treatment of disease in patients" is this not what medical devices are concerned with - the same devices we "fiddle about with" and give advice relating to? For many specialist clinical knowledge is required to do this job. Specialist clinical knowledge does not mean I have to be a Doctor or Nurse.
