The battery powered thermometer works by detecting the nerve damage in the limb, which can lead to loss of sensation, development of serious ulcers and infections.

The device uses infrared light to measure changes in foot temperature at six sites in the patient’s foot, and a rise in temperature is indicates inflammation and nerve damage.

Using the device, the patient compares the temperatures at six different sites in the foot, and a difference of more than four degrees Fahrenheit (2C), for two days or more indicates the development of an ulcer.

Previous studies showed that the device reduced ulcer rates in diabetic patients by a third, compared to those who did not use the device, and researchers are conducting a large-scale study of the device at the Oslo University Hospital, in Norway.