Ok, mine was 2 wks ago at a Sleep Center. It followed my night study so I was already hooked up/wired. They woke me up at 5:15am and had me sit up in a chair until 7am, then it was off to bed again for 20min like Chronie said "whether you sleep or not. Then up to the chair again for another 2 hrs. This happened at 7a,9a,11a,1p & 3pm. I could only have water that morning and they brought me cheese/crackers/fruit/granola bar after my 7am nap. They keep you wired up so I was told not to leave the building. I wouldn't have gone anywhere anyway looking like that! lol!
For lunch they brought me a Subway sandwich and Sprite. No caffeine allowed.
I don't know how old your ds is but I'd suggest books and puzzle games too. Maybe borrow/rent a portable DVD player if you don't have one and rent a few movies. I brought my laptop and caught up on emails since the bldg. was WIFI.
If there are certain snacks he likes, bring those as long as they are "healthy" and don't contain caffeine or lots of sugar.
They keep the wires on but there were less wires/straps than the night study had so you can move around the room more easily and it's not as annoying!
Hope that helps!