The Osler-class hospital transports were a type of United Federation of Planets starship on active duty during the 23rd century. (Starfleet International)
The class consisted of Ptolemy-class transport/tugs with specialized transport containers attached. Ptolemys could carry up to two of these hospital modules by extended the ship's warpfield.
The class was named for William Osler (1849-1919), a Canadian physician who has been described as the "father of modern medicine."