Detection of blackbody radiation during fiber guided laser-tissue vaporization

Laser-tissue vaporization through a fiber catheter is evolving into a major category of surgical operations to remove diseased tissue. Currently, during a surgery, the surgeon still relies on personal experience to optimize surgical techniques. Monitoring tissue temperature during laser-tissue vaporization would provide important feedback to the surgeon; however, simple and low-cost temperature sensing technology, which can be seamlessly integrated with a fiber catheter, is not available. We propose to monitor tissue temperature during laser-tissue vaporization by detecting blackbody radiation (BBR) between 1.6 µm-1.8 µm, a relatively transparent window for both water and silica fiber. We could detect BBR after passing through a 2-meter silica fiber down to ∼70°C using lock-in detection. We further proved the feasibility of the technology through ex vivo tissue studies. We found that the BBR can be correlated to different tissue vaporization levels. The results suggest that this simple and low-cost technology could be used to provide objective feedback for surgeons to maximize laser-tissue vaporization efficiency and ensure the best clinical outcomes.