The Emergency Medical Holographic program (EMH) was a sophisticated hologram used on most Federation starships in the late 24th century that was designed to provide assistance to medical staff in times of emergency. It was developed by Dr. Lewis Zimmerman on Jupiter Station and was formally known as EMH Program AK-1 Diagnostic and Surgical Subroutine Omega-323. (DS9: "Doctor Bashir, I Presume"; VOY: "Projections", "Lifesigns")