Which episode of Law & Order: SVU do Olivia and Elliot go undercover as nurses/doctors?

I don't remember them ever going undercover as nurses/doctors, but in season 8, Olivia goes undercover as Persephone, a woman involved in a violent activist group; season 9, ep. 15, she goes undercover as an inmate, and gets sexually assaulted; she's also gone undercover as a cleaning woman in a factory, a madame, and a few other things.. In the first episode of season 7, Elliot goes undercover as a convict; season 10, ep. 7, he goes undercover again while investigating an animal smuggling ring. There's others too, but none that I can remember them going undercover as doctors...sorry, I don't know if that helped.