The African-American lab technician, Vivien Thomas, whose surgery helped save the lives of millions of babies but whose work went unrecognised for years. Claire Bowes has been listening to archive recordings of Vivien Thomas describing his long partnership with Dr Alfred Blalock, the man solely credited with inventing an operation in 1944 which helped manage a congenital heart defect called Tetralogy of Fallot. (Photo: Vivien Thomas, US Surgical Technician, 1940) (Audio: Courtesy of US National Library of Medicine)