BBC Science Correspondent James Wilkinson reports: "The new device is likely to prevent considerable suffering"

The laser doppler scanning machine produces a detailed picture of a wound, which makes diagnosis quicker and can prevent unnecessary skin grafts.

The laser moves back and forth over the burned area to detect whether the blood vessels are still healthy. This is displayed as an image on a computer screen. A normal, healthy hand shows up as red; areas where the blood vessels are damaged show up as blue.

Damaged skin will usually need to be replaced using a graft, and the "surgical map" produced by the machine will tell the surgeons precisely where to operate.

New technique

Three-year-old Connie Smith was one of the first to benefit from the new technique when she burned her hand reaching behind a radiator to retrieve a toy.

Connie trapped her hand behind a radiator pipe

Initially, she was treated with cold running water and her hand was wrapped in cling film. At first, doctors thought the injury was so bad she might need a skin graft and sent her to the burns unit at Stoke Mandeville Hospital, Aylesbury.

"She was quite upset," her mother, Dorothy, said. "She was crying a lot and I think the fact she was taken to the burns unit made us more aware of how serious it was."

But within an hour of arriving at Stoke Mandeville, Connie was examined using the new device and it was decided to pursue less aggressive treatment.

Superficial injury

Mr Paul Banwell, Duke of Kent Research Fellow at Stoke Mandeville, said the scan showed Connie's injury to be superficial.

Paul Banwell: Major advantages

"Using this information, the decision was made not to operate," he said. Her hand was dressed and she stayed in hospital for two nights for further investigation and observation.

The decision not to operate had many advantages.

"Any surgical intervention is stressful for the patient," said Paul Banwell. "It involves more scarring in terms of taking the skin graft and, generally, the time spent in hospital is longer. So her road to recovery was actually quicker than if we had operated."

Cost benefit

Looking a Connie's hand several months after the accident, it is clear the doctors made the right decision. The hand has very little scarring and the skin displays only minimal discoloration.

Connie's hand is recovering well

Thousands of the 150,000 patients treated for burns each year could benefit from the new scanning machine.

Current methods for assessing the depth of a burn are time-consuming and rely on a high degree of clinical judgement built up over many years of looking at and treating such injuries.