Optimizacija laserskih parametara za primene u interakciji sa materijalima biološkog porekla

Abstract

Primena lasera u medicini (više od pola veka) beleži konstantan napredak zahvaljujući razvoju laserske tehnologije i optičkih sistema. Iako se mnogo laserskih tehnika svakodnevno primenjuje, postoji još mnogo nerešenih pitanja i problema u razumevanju mehanizama interakcije laserskih snopova sa biološkim materijalom i humanim tkivom. Razvijeno je mnogo teoretskih pristupa interakciji, za specifične grane medicine i specifične tipove lasera (uz radne parametre izabranog dinamičkog režima). Ponovljivost rezultata definisane interakcije zavisi od stabilnosti i preciznog definisanja parametara dejstva laserskog snopa, ali su zahtevi statističkih prilaza pojedinoj aplikaciji vezani za odabrani statistički skup, gde dolazi do izražaja individualnost terapijskih parametara. Izbor talasne dužine, frekvencije repeticije, energije (gustine energije i gustine snage) i širine impulsa, su podjednako važni u određivanju efikasnosti procedure i smanjenju neželjenih efekata po humana tkiva, zavisno od vrste tkiva (biostimulacija, biomodulacija, koagulacija, nekroza, karbonizacija, opekotine, oštećenje očnog aparata) sa biomedicinske strane, a po vek uređaja sa tehničke strane. Talasna dužina uz odgovarajući izbor radnih parametara, omogućuje proces optimizacije rada laserskih sistema i efektivniju interakciju laserskog snopa sa tkivom ili protetičkim materijalom. Svaki laserski uređaj ima svoj način optimizacije procesa apsorpcije laserskog snopa u odgovarajućoj strukturi. Primena različitih tipova lasera je dokazana u mnogim oblastima medicine (oftalmologija, stomatologija, dermatologija, urologija, vaskularna hirurgija i dr.). Interakcija laserskog snopa sa materijalom se razmatra danas u nekoliko vremenskih domena rada, od kontinualnog do femtosekundnog. Zavisno od dinamičkog režima rada lasera, pojavljuju se različiti problemi tehničke (inženjerske) i teorijske prirode. Pojedine konstrukcije lasera su podjednako zastupljene u industriji, elektrotehnici, mikroelektronici, nauci i medicini. Zato se i modelovanje interakcije mora posmatrati kroz nekoliko nivoa. U cilju modelovanja potrebno je izabrati optimalan pristup i mehanizam, i definisati parametre biomaterijala od interesa za taj model...

The application of lasers in medicine (more than half a century) records continued progress with the development of laser technology and optical systems. Although many laser techniques have been applied on a daily basis, there are still many unresolved issues and problems in understanding the mechanisms of interaction of laser beams with biological materials (biomaterials in general) and human tissue. Many theoretical approaches about the interaction have been developed, for particular branches of medicine and specific laser types (with operating parameters of the selected dynamic modes). Repeatability of results (issues) of the defined interaction depends on the stability and precise definition of the parameters of the laser systems and beam effects, but the demands of statistic approaches to an interaction are related to the selected statistic set, where the individuality of therapeutic parameters is emphasized. The selection of wavelength, repetition rate, energy (energy density and power density) and pulse width, are equally important in determining the efficiency of procedures and reduction of adverse effects on human tissue, depending on the tissue type (biostimulation, biomodulation, coagulation, necrosis, carbonization, burns, damage to the optic apparatus) from the biomedical side, and the lifetime of the device, from the technical side. The wavelength with an appropriate choice of operating parameters enables optimization process of the laser system operation and more effective laser interaction with tissue or prosthetic material. Each laser device has a way of optimization process of the laser beam absorption in a particular structure. Application of different laser types has been demonstrated in many areas of medicine (ophthalmology, dentistry, dermatology, urology, vascular surgery, etc.). The interaction of laser beam with material is being considered today in several time domains, from continuous to femtosecond one. Depending on the dynamic laser mode, there are various problems of technical (engineering) and theoretical nature. Some laser constructions are equally represented in industry, electrical engineering, microelectronics, science (in general) and medicine. That is why the modeling of interaction must be considered at several levels. For the purpose of modeling, it is necessary to select an optimal access and a mechanism, and to define the biomaterial parameters of interest, for that model. In this thesis, the processes associated with application of laser beam are being analyzed, with conditionally higher power density, during the interaction with tissue. The contemporary requirements for medica...