How to feel useful again..?

Just recently my dad has had some really bad health problems and he had a syncopal episode with a seizure a few weeks ago. He is okay now, but lost his license and can't go to work for a few months. Today he told me he feels useless and feels like he has no purpose anymore.. This was really hard for me to hear, as I am his only child and so close to him. I was just wondering if anyone had any ideas to keep him busy or help him feel useful again during his "time off"? He's not a very active person, yet he doesn't like to sit all day. But any type of ideas are greatly appreciated!! :/