Optical feedback signal for ultrashort laser pulse ablation of tissue 1

An optical feedback system for controlled precise tissue ablation is discussed. Our setup includes an ultrashort pulse laser USPL., and a diagnostic system utilizing analysis of either tissue fluorescence or plasma emission luminescence. Current research is focused on discriminating hard and soft tissues such as bone and spinal cord during spinal surgery using either technique. Our experimental observations exhibit considerable spectroscopic contrast between hard and soft tissue, and both techniques offer promise for a practical diagnostic system. q1998 Elsevier Science B.V.