New Delhi, June 23 -- During a trek last year, Anshul Bhatt realised that the family's eleven-and-a-half-year-old Labrador, Max, was in severe discomfort. While he would normally be running about in the wild, never refusing a dip in a pool of water, he now sat licking his paws in pain. A visit to the vet revealed late-stage arthritis.

"Since it wasn't diagnosed in time, the treatment is less effective. You can alleviate the pain and make dietary changes, but there isn't much you can do beyond a point," says Bhatt, 16, a class XI student at Dhirubhai Ambani International School, Mumbai.

The incident got him thinking. By the end of the year, he arrived at the design for PawPath, a non-invasive gait monitoring device that detects orthopaed...