Smart Holmium Laser for Endoscopic Lithotripsy

An optical feedback control system for the pulsed holmium: YAG surgical laser will be developedto enhance its safety for endoscopic lithotripsy. The system will enable rapid, intrapulse discriminationof, and selective energy delivery to, calculi versus surrounding soft tissue. This technological advancewill significantly reduce the risk of laser-induced tissue damage during lithotripsies performed with theholmium laser -- a clinical application for which this laser is soon expected to receive FDA approval.Phase I has several objectives: 1) record the time-dependent, spectrally-resolved optical emissionsinduced by pulsed holmium laser irradiation of calculi, urinary tract tissue, urine, blood, etc.; 2) use theseemission data to develop an algorithm for detecting, early in a pulse, whether the laser is beingdischarged on a calculus; and 3) assemble and demonstrate a breadboard opto-electronic control modulewhich will use the developed algorithm to rapidly terminate the laser pulse if the delivery fiber is nottargeted on a calculus, thus limiting the exposure risk to healthy tissue. Completion of these Phase Itasks will demonstrate the technical feasibility of the "smart" holmium laser and lay the necessaryfoundation for subsequent Phase II development efforts.