If it is a long-term use, the home is an elevator apartment, the old man is clear-headed, the hand is more flexible, then you can consider buying an electric wheelchair.
Temporary use, buy a three or five hundred ordinary steel manual wheelchair on the line.
There is another situation, if the home is the kind of stairs, not the elevator apartment, it is best to choose aluminum wheelchair, so the lighter, can be folded, the most convenient.
The specific purchase skills, you can go to the wheelchair online to take a look, I also bought a wheelchair there to learn.