HCA officials say they instituted the screening system to reduce overcrowding in emergency rooms.
It was unclear who developed the screening system, hospital officials said.
The indictment said Mr. Redburn was associated with a company, Air Tag Inc., that was testing the feasibility of the screening system.
The former Metropolitan police officer conceded the screening system was flawed and said he was not clinically qualified to manage a health risk.
She said she was feeling fine at Heathrow but the screening system could not cope with the arrival of 50 medics returning home from Sierra Leone.
The T.S.A. eventually found its way to the screening system it is using now, which searches for weapons instead of relying primarily on profiling people.
Several former emergency department doctors at Lawnwood Regional Medical Center in Fort Pierce, Fla., said they frequently had felt compelled to override the screening system in order to treat patients.
The breakdown in the system was so great that the manager of the screening system called the wrong number for an on-call specialist at an infectious diseases hospital when concerns were raised on 28 December 2014, the day the Scottish volunteer nurse Pauline Cafferkey passed through the airport.
Scott Scherer, a member of the Nevada State Gaming Control Board, which ensures that casinos do not violate their licenses, said the board was confident enough in the system to let MGM go ahead, even though it did not expect the screening system to be 100percentt effective.
The letter, which can be viewed in full on the FDA's web site,maintains that the screening system poses "minuscule" health risks to passengers:Several groups of recognized experts have been assembled and have analyzed the radiation safety issues associated with this technology.
The screening system plays a pivotal role for reliably identifying improved enzyme variants.
