I'm looking for a general term describing all kinds of equipment and other means of improving the life quality of a physically and/or mentally challenged individual. Let's say that a crude'ish definition might be something as follows.
Something needed to compensate for disabilities so that the subject can live self-reliantly and function socially.
For instance a visual aid would be a pair of medical glasses but also, much more specialized, Brail typewriter. It could be an app on a phone suggesting by color the amount of food for a person with ADHD, other neuro-psychiatric disease or arrested development. It could be a talking clock stating the time of day and suggesting type of meal for patients with dementia or post-stroke cases. Voice control for computer (typing in text and operating the cursor) for a person with weak or unsteady arms and/or hands.
A counter-example for something that isn't such an aid is Siri, augmented reality, a car's GPS navigator or a stroller. Those are aiding but not due to a disability but rather convenience. (Of course, many ideas thought of with the disabled in focus has later on become a common man's best friend.)