Hi, sounds like an interesting project! I alternate between wheelchair, 3 types of rollator - 3 wheel, 4 wheel with storage, and 4 wheel *bigger wheels for outside & kerb helper, and various walking sticks, depending on mobility levels on any given day, so know a bit about mobility aids.
I'm not elderly but don't think someone elderly with a mobility issue would have such different problems, rather it would depend on level of ability/range of movement etc so not sure if you'd like some input?
For now, I'd say that mobility aids are too expensive here, some are downright uncomfortable to use, and a lot of them just aren't ergonomic in terms of design. Also, they're awkward in shops, a lot of places just don't consider wheelchair or rollator users at all with the result that your world gets smaller and smaller the worse your mobility gets to the point that odious places such as Tesco are the only real options.
A lot of the time you're required to use the back door if the place is half accessible. Recently I booked a hotel room in Dublin as I was attending a seminar close by, had enquired about accessibility and assistance bringing in bag etc.. and was told it was all good. Got there to find that their idea of accessible was me being lifted up six steps by two employees who it turned out, hadn't even received manual handling training. I just left it and went home...
I really wanted to do an Art and Design course to help with pain management mostly, but could not find an accessible college anywhere close enough to where i live and would be able to drive to - have limited endurance for driving so 45 mins is absolute max on a 'good' day. There are four institutions which are within 19 miles, one only recently established, but none have accessible Art rooms, which was very disheartening.
It's a huge area of study for you. If you want to be specific or ask questions as to the type of input you'd like, I would be happy to oblige. Would also suggest contacting the Irish Wheelchair Association as they're a mine of information.
All the best