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 make 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 produce oxygen by separating it from the rest of the air, using a vacuum created by running water. Then they designed special bags that can store and deliver oxygen – even when the electricity cuts out. Their systems have provided oxygen for hundreds of sick children in Uganda. People Fixing the World hears the story of these remarkable inventions. Produced and presented by Ruth Evans Picture credit: Peter Casamento