A so-called smart knife could help physicians determine during surgery whether tissue they\'re removing is cancerous, British researchers say. In a first operating room test, the iKnife diagnosed tissue samples from 91 patients with 100 percent accuracy, instantly providing information that normally requires laboratory tests that can take up to a half hour, researchers at Imperial College London reported Wednesday. The iKnife is based on electrosurgery, in which surgical knives use an electrical current to rapidly heat tissue, cutting through it while minimizing blood loss. As they cut they vaporize the tissue, creating smoke that is normally sucked away by extraction systems. The iKnife system analyzes the smoke, using mass spectrometry to determine in seconds whether tissues were cancerous. Lipid components in the smoke created from different types of tissues have characteristic signatures, the researchers said. A surgeon using an intelligent knife could know what kind of tissue he or she was dealing with almost instantaneously, they said, and make decisions on the spot about how to proceed. \"One can sample a bit of tissue and the result is displayed on the screen in a second. It allows fast analysis and more sampling points,\" ICL chemist Zoltan Takats said.