In many cases, having surgery to remove a tumor means having to go back for another surgery because some of the tumor was left behind. This is because it’s very difficult to tell by sight whether tissue is cancerous or not.Researchers at London’s Imperial Hospital have created an intelligent scalpel that can tell if the tissue it is touching is healthy or cancerous.

The “iKnife” works by instantly sampling the smoke that rises from an incision. The smoke contains important biological information that can be analyzed within three seconds. If the smoke says that the doctor missed part of the tumor, he or she can immediately remove the rest of the diseased tissue. In its first study, the iKnife diagnosed cancerous tissue with a 100 percent accuracy rate.

According to the researchers, the iKnife can reduce costs to both the health industry and patients by reducing the number of repeat surgeries required. Plenty more testing needs to take place before the iKnife can be widely used, but at the moment the biggest obstacle facing the researchers is the cost: £200,000 (or $300,000 USD). The price will naturally fall once the trials are completed and the scalpel can be sold on a wide scale.