Smell the future

The nose of a dog is incredibly sensitive. And odour contains information. With the help of AI, electronic 'noses' are being used to sniff out complex odours, including diseases. Chris Vallance visits a company developing the technology. Also this week: Shiona McCallum is in Paris to see the tech that can help us understand sleep. And Liv McMahon accompanies Chris on a walk in a park. There, they…