The Doctor, an Emergency Medical Hologram (EMH), is a fictional character portrayed by actor Robert Picardo in the television series Star Trek: Voyager, first aired on UPN between 1995 and 2001. He is an artificial intelligence manifesting as a holographic projection, and designed to be a short-term adjunct to medical staff in emergency situations. However, when the USS Voyager is stranded on the far side of the galaxy without medical personnel, he is forced to act as the starship's permanent chief medical officer. In an example of the Star Trek franchise's exploration of artificial intelligence, a rudimentary algorithm becomes a major character in the show.