At the beginning of the movie, Christian Slater's character "activates" a sort of "communicator" and speaks into it. This is actually nothing more than a simple LED reading light for books and a popular give-away at tech fairs.
When the colonel locks Ava in medical, his key card is required to open the door. The doctor takes it so he can get in while the colonel is medicated. Later, when the two of them return to medical, the colonel is able to enter without his key card.