Silver halide fiber optic radiometric temperature measurement and control of CO₂ laser‐irradiated tissues and application to tissue welding

Tissue heating by laser irradiation has attained importance in many clinical applications. Accurate temperature measurements of laser‐irradiated tissues are difficult to achieve, and experiments have produced conflicting results. Fiber optic radiometry allows temperature measurement of laser‐irradiated tissues by remote sensing of the emitted infra red (IR) radiation. We have developed an IR fiber optic radiometer capable of accurate tissue temperature measurements (± 0.2°C) and utilized it to monitor and control the heating of tissues by CO₂ laser irradiation. Tissue temperature control of ± 2.5°C was achieved. This system was used to control tissue temperature during CO₂ laser‐assisted welding of urinary bladders in rats. The strength of the welds was recorded for different welding temperatures. A temperature of 55°C was found to be optimal. © 1994 Wiley‐Liss, Inc.