A clever invention is saving the lives of hundreds of children. Pneumonia kills about 1.4 million children under five every year. Treatment with concentrated oxygen could save many of them, but the machines that provide it need a reliable source of electricity. Some hospitals have frequent power cuts though, which can be fatal. So scientists in Australia and Uganda came up with an innovative way to deliver oxygen when the electricity cuts out. Produced and presented by Ruth Evans. Repeat. This episode was first broadcast on 12 May 2020.