The "intelligent" knife that knows when it is cutting through cancerous tissue is being tested in three London hospitals. Experts believe the wand-like device, the first of its kind in the world, will revolutionise cancer treatment by removing uncertainty from surgery.
In an early study, the "iKnife" identified malignant tissue in cancer patients undergoing operations with 100% accuracy. After more extensive trials it could be approved for general use in operating theatres within three years.
Surgery is often the best hope of a cancer cure, yet even the best surgeons cannot be sure of removing every part of a tumour. In the case of breast cancer, more than 20% of the cancerous tissue may be left behind.
Warning: This footage contains graphic images of surgery.
The iKnife helps the surgeon by indicating exactly where the cancerous tissue is, and when it has all been removed.
The device is a hi-tech form of "electric scalpel", a tool routinely used by surgeons that uses electricity to sear through membranes and internal organs.
As the knife cuts, smoke from the burned tissue is pumped through a tube into a mass spectrometer, a machine that uses magnetism to produce a chemical "fingerprint" of the atoms fed into it.
The customised version being tested at St Mary's, Hammersmith and Charing Cross hospitals in London employs a user-friendly "traffic light" display.
The iKnife's inventor Dr Zoltan Takats, from Imperial College London, said:
The surgeon on the spot has to make a decision on where to cut and what to remove.
The general solution is intra-operative histology. A tissue sample is removed from the patient and sent to the histology lab for analysis.
But even in vast hospitals it can take 10 to 30 minutes. There are also reliability issues - the histology team are in an extreme rush and having to do things as fast as possible.
We can give feed back to the surgeon in some cases in less than a second. This could be a real game-changer for tumour resection surgery.
Although the current study focussed on cancer diagnosis, Dr Takats says the iKnife can identify many other features, such as tissue with an inadequate blood supply, or types of bacteria present in the tissue. He has also carried out experiments using it to distinguish horsemeat from beef.