A drone has delivered a kidney to a Baltimore hospital, where doctors then successfully transplanted the organ into a patient.
It was the first live test of the kidney-carrying aircraft, designed by doctors and engineers at the University of Maryland to help speed up the transfer of organs.
The test flight was a brief 4.8 kilometres and took just under 10 minutes, but Joseph Scalea, a University of Maryland Medical Centre transplant surgeon, said it represented the potential for many more lives to be saved.