Dr. Sandi Zober was a medical professional associated with Mercy Hospital in the Mission District of San Francisco in 1986.
While Dr. McCoy, Admiral Kirk, and Dr. Gillian Taylor were searching for clues as to the injured Pavel Chekov's whereabouts, somebody paged Dr. Zober. (Star Trek IV: The Voyage Home)
This character was only mentioned in dialogue.
Sandi Zober was actually the name of director and star Leonard Nimoy