Tolmie, C. J.Marais, Charles Claude2016-11-162016-11-161999-05http://hdl.handle.net/11660/4547Media (CD-ROM) accompanying dissertation unreadable, possibly damagedEnglish: A Virtual Reality Gastrointestinal Trainer/Simulator has been developed to enable the simulation of gastrointestinal procedures on a personal computer (PC). Virtual Reality (VR) techniques are used in the construction of this computer-based system to enable the user to practice basic identification, navigational and therapeutical skills. The system consists of a computer-based simulator, a 3-dimensional (3-D) tracker, an endoscope/endocamera and a life-size gastrointestinal model. A normal endoscope/endocamera is used with a hollow transparent life-size gastrointestinal model to provide maximum realism. The computer-based simulator contains a virtual 3-D model of the relevant gastrointestinal organ. Currently the stomach, esophagus and entry to the duodenum (upper G.I. region) are focused on. The position and orientation of the front tip of the endoscope/endocamera are tracked with the 3-D tracker. This data is relayed to the computer, which then calculates and displays the appropriate image on the computer screen as realistically as possible. The calculated image closely resembles the image which would be seen with a real endoscope/endocamera in a real patient. The image is continually updated in accordance with the movement of the endoscope/endocamera and the properties of the gastrointestinal model. Some of the main problems that had to be addressed during the development of the system are: obtaining a 3-D computer graphic model of the stomach with the same shape, size, colour and texture as a real stomach; the simulation of abnormal conditions like ulcers, and how they can be placed inside the 3-D computer graphic model; the simulation of therapeutic tools, like biopsy foreceps; the implementation of realistic, but cheap force feedback; and the deforming of the 3-D computer graphic model when the user touches the inside of the stomach with the tip of the endoscope/endocamera. The system is ideal for teaching, training, simulation, patient briefings and research. In this thesis the virtual reality system, its development and operation is described in detail.Afrikaans: 'n Skynwerklike ("virtual reality") gastrointestinale opleidings simulator is ontwikkel om gastrointestinale prosedures na te boots deur gebruik te maak van 'n persoonlike rekenaar. Skynwerklikheidstegnieke word gebruik met die ontwikkeling van hierdie rekenaargebaseerde stelsel sodat 'n gebruiker basiese identifikasie-, navigasie- en terapetiese tegnieke kan oefen. Die stelsel bestaan uit 'n rekenaargebaseerde simulator, 'n drie-dimensionele (3-D) volger, 'n endoskoop/endokamera en 'n lewensgrootte gastrointestinale model. 'n Werklike endoskoop/endokamera word gebruik in 'n hol, deurskynende, lewensgrootte gastrointestinale model sodat die simulasie so realisties as moontlik kan voel. Die rekenaargebaseerde simulator gebruik 'n virtuele 3-D model van die relevante gastrointestinale orgaan. Hierdie studie fokus op die maag, esophagus en die ingang na die duodenum. Die posisie en orientasie van die punt van die endoskoop/endokamera word gevolg met die 3-D volger. Hierdie data word gegee aan die rekenaar wat dan die gepaste beeld so realisties as moontlik genereer en op die skerm vertoon. Die gegenereerde beeld lyk baie soos 'n beeld wat gesien sou word met 'n regte endoskoop/endokamera in 'n regte pasient. Die beeld word deurlopend opdateer volgens die beweging van die gastroskoop en die eienskappe van die gastrointestinale model. Sommige van die probleme wat aangespreek moes word gedurende die ontwikkeling van die stelsel is: die generering van 'n 3-D rekenaar grafiese model van die maag met dieselfde vorm, grootte, kleur en tekstuur as 'n regte maag; die simulasie van abnormale kondisies soos maagsere, en hoe hullle in die 3-D rekenaar grafiese model geplaas kan word; die simulasie van terapetiese gereedskap, soos biopsie-tange; die implementasie van realistiese, maar goedkoop, krag terugvoer ("force feedback"); en die vormverandering van die 3-D rekenaar grafiese model wanneer die gebruiker die punt van die endoskoop/endokamera teen die wand van die maag laat raak. Hierdie stelsel is ideaal vir onderwys, opleiding, simulasie, die inlig van pasiente en navorsing. Die skynwerklike stelsel, die ontwikkeling daarvan en die werking daarvan word in hierdie tesis beskryf.enSynthetic training devicesMedical instruments and apparatusDissertation (M.Sc. (Computer Science and Informatics))--University of the Orange Free State, 1999Medicine -- Study and teaching -- Simulation methodsDissertationUniversity of the Free State