In the United States, The National Board of Diving and Hyperbaric Medical Technology (NBDHMT) was formed in 1991 and introduced a certification program for all technologists working in the field as well as an "approved" introductory training course for those desiring to enter the field of Hyperbaric Medicine. It was not the intention of the NBDHMT to provide an "entry level" pathway for certification in hyperbaric technology (Certified Hyperbaric Technician). Certification was offered as an "added qualification." The broad cross section of health care providers including licensed registered and vocational nurses, therapists, chamber technicians, physician assistants, diving medical technicians, corpsmen, physiologists, emergency medical technicians, paramedics, life support technicians, researchers and physicians involved in the delivery of undersea, hyperbaric and aviation medicine and related research activities.