Medical Consultant Program Beta one was the computer filename for The Doctor's holographic simulation of Dr. Crell Moset used to remove a cytoplasmic lifeform attached to B'Elanna Torres in 2375. He created it because Moset was the greatest expert in exobiology known to the Federation.
Crell was friendly and highly competent which impressed The Doctor. He recreated his own lab in order to have the equipment to save Torres' life. Crell bragged to The Doctor that he was able to cure disease during the horrible Occupation of Bajor, even though he was forced to improvise treatments in the ill-equipped Bajoran hospitals.
He came up with a plan to apply energy to the lifeform's neurostatic nodes in order to make it release Torres. The Doctor believed that that would kill the alien, but the Crell hologram stated that it would be the only way to save her. After the procedure was completed, without the death of the lifeform, Crell was feeling superior and wanted to write a paper about the procedure.
When The Doctor found out that Moset's knowledge came from inhumane experiments conducted on thousands of Bajorans, The Doctor confronted the Moset hologram. It said that ethics are arbitrary and reminded The Doctor that he took an oath as a medical practitioner, and moreover that he had already used his research to save Torres. The Doctor deleted the program because he could not condone Moset's actions. (VOY: "Nothing Human")