OligoChannel spectral analysis in stereotactic laser neurosurgery [Elektronische Ressource] / presented by Klaus Greger

Dissertationsubmitted to theCombined Faculties for the Natural Sciences and for Mathematicsof the Ruperto-Carola University of Heidelberg, Germanyfor the degree ofDoctor of Natural Sciencespresented byDiplom-Physicist: Klaus Gregerborn in: Schw¨abisch Gmund,¨ GermanyOral examination: 28.5.2003OligoChannel Spectral Analysisin stereotactic laser neurosurgeryReferees: Prof. Dr. Josef F. BilleProf. Dr. Wolfgang SchlegelAbstractIn stereotactic laser neurosurgery a tumor in the human brain is resected bya pulsed high energy laser beam. The laser beams for diagnosis and ablation ofcancerous tissue are supplied through a probe. The whole resection is plannedwith a computer system. These planning data are based on previously obtainedCTandMRTimaging. Duringtheoperationthecompleteprocess(diagnosisandresection) is guided and controlled by a computer system. One important partof the surgical system is the OligoChannel Spectrum Analyzer (OCSA), of whichthe principles and development are described in this work. The OCSA analyzestheautofluorescencespectrumofeachobservedtissuepointinordertodetermineits kind. This is possible since autofluorescence spectra of healthy and canceroustissue show characteristic differences. In contrast to commonly used techniques,theOCSAusesonlyafewdetectors. ByevaluationofthedataobtainedwiththeOCSA,animmediatedecisioncanbemadewhetheraspecifictissuepointshouldbe ablated or not.