Thank you for your reply. However, I don't quite understand why the possibility of using the medical service will disqualify his visa application. Is there such a policy?
Let me explain my father's condition a little bit. First of all, I don't think he will have the need of seeing a doctor for his staying in the States since he has all the necessary medications with him. He just needs help getting around the house. To make my mom's job easier, we have a care taker for him. If my parents come, I would like to have the care taker come as well.
Do you think this is possible? Thanks a lot.