 Ron Stewart, the show's medical director, was instrumental in organizing emergency health services in southern California earlier in his career during the 1970s, in the paramedic program in Pittsburgh, and had a substantial role in the founding of the paramedic programs in Toronto and Nova Scotia, Canada.Throughout the 1970s and 1980s, the paramedic field continued to evolve, with a shift in emphasis from patient transport to treatment both on scene and en route to hospitals.This led to some services changing their descriptions from "ambulance services" to "emergency medical services".