Computer controlled Nd:YAG laser system for medicine

Several medical fields are concerned by thermal effects of lasers. Mathematical models of thermal effects can help to define lasers parameters in relation to therapeutic use, but an exact quantification of the Nd:YAG laser induced damage is not possible at the time of the treatment. Adaptive control is proposed as a useful process for an improvement of Nd:YAG laser treatments. A computer controlled Nd:YAG laser system with a closed loop capability was developped. Infrared radiometry provided noncontact temperature measurement for real time coagulation and ablation control. The controller design is based on the predicted response, defined by mathematic models. Deviations of the actual response, beyond an established tolerance, caused the Nd:YAG laser system to adjust the laser parameters automatically.