Computers use logic. Dementia does not.
Dementia symptoms are often extremely personal. They might reflect the person's upbringing or their fears and prejudices. Some have huge personality changes, others do not. PWDs are often delusional and live in a world that's very far from reality. But again, the things they obsess about or believe to be happening are very personal to them. They are affected by their environment which becomes unfamiliar to them and by the people around them. They might cling to those people or fear and resent them. They don't understand anything is wrong so they think the world around them is wrong. They are reluctant to co-operate with medical examinations, tests and scans. Their mood can change from one moment to the next - there is no consistency.
Carers must be constantly on their guard, ready for 'the next thing' whatever that might be. Rationality and logic are useless tools in the world of dementia. You have to be crafty, resourceful and always ready to fail and have to try something else.
For these reasons, I think computers and AI will only ever have limited usefulness in the field of dementia. I just don't feel sitting somone with dementia in front of a hearing tablet that will prompt speech for them is anything more than a drop in the ocean. About as much use as a pill dispenser, i.e. it might work on some occasions. It might work for a few weeks but ultimately the PWD needs people around them not machines.
Of course, if you could come up with a system that predicts when a PWD is going to soil themselves and walk it round the house, that would be great. And if the AI robot could wash and change the PWD too that would be brilliant. Diagnosis is such a small part of things. It's the years spent looking after the person with dementia that's the hard part.
Until neuroscientists can look at a brain scan and say, 'look - you can see what his thoughts are,' we still know almost nothing about brains. Being with someone who has dementia actually gives you a good view of just how amazingly complex, complicated and unbelievable our brains are.
Just my opinion...