Forest Dewey Dodrill, working closely with Matthew Dudley, used the machine in 1952 to bypass Henry Opitek's left ventricle for 50 minutes while he opened the patient's left atrium and worked to repair the mitral valve. In Dodrill's post-operative report, he notes, "To our knowledge, this is the first instance of survival of a patient when a mechanicaly heart mechanism was used to take over the complete body function of maintaining the blood supply of the body while the heart was open and operated on."