How do I get past the guard?

Hint 1 of 5:

Well, he doesn't seem too alert.

Hint 2 of 5:

He should be in for a shock.

Hint 3 of 5:

Use the shock therapy machine on him.

Hint 4 of 5:

You don't have the machine?

Hint 5 of 5:

Look in the cabinet in the Insane Ward.