"The Doctor" was AMO's Emergency Medical Holographic program (or "EMH") and Chief Medical Officer. The EMH Mark I, of which The Doctor was an example, was a computer program with a holographic interface in the form of a Human male Doctor. Although his program was specifically designed to function in emergency situations only. Over the years, The Doctor expanded his program a great deal: he acquired many interests and hobbies, developed close personal friendships with many members, and even fell in love. He was a brilliant yet compassionate man who proved his worth and loyalty to all crew members throughout the years, gaining their well-earned respect as an individual with the same rights as everyone else on board.