"Based on research results of Sandra Schweizer and Gerhard Lammel during their PhD thesis' at the Swiss Federal Institute of Technology Lausanne in the group of Prof. Philippe Renaud"--Pref. / Includes bibliographical references and index.

No description available.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 147-154) Also available in print.

The master´s thesis deals with creating a usable methodology for measuring the position of kinematic points McPherson suspension using optical scanners available on ÚADI. The answer lies in comparing the measurement results obtained using the scanners ATOS and TRITOP with regard to the different measurement methods. Using analytic geometry and the software ADAMS are fixed characteristics of the suspension, they are compared with values measured on the geometry. Finally, it evaluated the accuracy of measurement methods.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Interdisciplinary Science, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Richard Eugene Hamilton. / M.S.

No description available.

Radiotherapy is a prominent cancer treatment modality in medicine, aiming to deliver adequate doses to the target while minimizing harm to healthy tissue. Recent advancements in computer technology, machine engineering, and imaging have facilitated intricate treatment planning and accurate radiation administration. These advancements have allowed for more precise dose distributions to be delivered to cancer patients. However, even small discrepancies in setup or delivery can result in significant dose variations. While treatment planning systems provide 3D dose calculations, there is currently a lack of 3D measurement tools in the clinic to verify the accuracy of dose calculation and delivery. Presently, medical physicists rely on 2D dose plane comparisons with treatment planning calculations using gamma index analyses. However, these results do not directly correlate with clinical dose-volume constraints, and detecting delivery errors using 1D or 2D dosimetry is challenging. The implementation of 3D dosimetry not only ensures the safety of radiation treatment but also facilitates the development of new emerging radiation treatment techniques. This study aims to commission and validate a clinically viable optical scanner for 3D dosimetry and apply the developed system to address current clinical and pre-clinical challenges, thereby advancing our understanding of treatment uncertainties in modern radiotherapy. The optical CT scanner that was developed comprises four key components: an LED illuminator, an aquarium with matching fluid, a fiber optic taper, and a CCD camera. The LED illuminator emits uniform and parallel red light at a peak wavelength of 625 nm and a full width at half maximum (FWHM) of 20 nm in continuous mode. The aquarium is constructed with transparent acrylic walls and is designed to accommodate the 3D dosimeter PRESAGE, which can be fixed on a rotation stage inside the tank. Clear acrylic has excellent optical clarity and light transmission, with a refractive index of 1.49 that is close to the average refractive index (1.54) of PRESAGE. To match the refractive index of the 3D dosimeters, a matching liquid composed of 90% Octyl Salicylate and 10% Octyl-P-Methoxy Cinnamate is filled in the tank. The fiber optic taper serves two functions: first, it demagnifies the projection images while preserving their shape, and second, it effectively reduces the acceptance angle of the light reaching the CCD camera. The CCD camera used in the system is an Allied Vision model with a resolution of 0.016 mm, capable of acquiring 2D projection images from various angles. The principle of the optical CT scanner follows that of CT imaging, where 2D projection images from different angles are used to reconstruct volumetric 3D dose images using the filtered back projection technique. To validate the dosimetric measurements and assess the uncertainties of the 3D dosimetry system, 21 benchmark experiments, including mechanical, imaging, and dosimetry tests were conducted. Furthermore, the developed system was employed for various applications, including patient-specific IMRT QA, small field dosimetry using kilovoltage and megavoltage beams, as well as end-to-end testing of stereotactic radiosurgery. A comprehensive analysis assessed uncertainties in each scanner component. Mechanical tests showed maximum uncertainties below 1%. By employing background subtraction and calibration techniques, measurement uncertainty was reduced to <1% in the optimal dose range. Background subtraction resulted in a remarkable 77% reduction in uncertainty by mitigating artifacts, ambient light, and refractive light. Reproducibility was excellent, with mean and standard deviation of dose differences below 0.4% and 1.1%, respectively, in three repeat scans. Dose distribution measurements exhibited strong agreement (passing rates: 98%-100%) between 3D measurements, treatment planning calculations, and EBT3 film dosimetry. Results confirm the optical CT scanner's robustness and accuracy for clinical 3D radiation dosimetry. The study also demonstrates that the developed 3D dosimetry system surpasses the limitations of traditional 2D gamma tests by providing clinicians with more clinically relevant information. This includes measured dose-volume histograms (DVHs) and the evaluation of gamma failing points in 3D space, enabling a comprehensive assessment of individual treatment plans. Furthermore, the study showcased the feasibility of utilizing this system to characterize a radiosurgery platform. It successfully assessed mechanical and dosimetric errors in off-axis delivery and evaluated the accuracy of treatment planning dose calculations, including modeling small fields, out-of-field dose, and multi-leaf collimator (MLC) characteristics. In addition, compelling evidence was presented that the high-resolution 3D dosimeter used in this study is capable of accurate dosimetry for both megavoltage and kilovoltage small fields. Importantly, the dosimeter exhibits no energy or dose rate dependence, further supporting its reliability and suitability for precise dosimetry measurements. The intricate and three-dimensional nature of dose distributions in modern radiotherapy necessitated the development of 3D dosimetry measurements, particularly for treatments with precise margins, such as SRS and SBRT. The newly developed 3D dosimetry system offers significant enhancements to current QA practices, delivering more clinically relevant comparison results and bolstering patient safety. Furthermore, it can be utilized for independent inspections across multiple institutions or remote dosimetry verification. Beyond its applications in clinical settings, the presented 3D dosimetry system holds the potential to expedite the development and utilization of novel radiation platforms.

This diploma thesis deals with the measurement of kinematic points of rear multilink suspension using 3D optical scanners TRITOP and ATOS and developing a measurement methodology of similar types of suspension with these scanners. Subsequently, kinematic features of this suspension are analyzed using the multibody system MSC.ADAMS / Car.

The objective of Master’s Thesis is to research the utilization of line optical sensors for object location´s and speed measurement in cooperation with PROTOTYPA company. At the beginning of the Thesis there is an explanation of CCD sensor components and photodiods working principals. Further are discussed particular methods of object sensing. There are schematics of different sensor locations and flying object. The other step deals with introduction to the question of ray impact on sensor in the way of using different light sources and optical systems. In the other part of the Thesis are presented two sensors, which have been chosen by PROTOTYPA company workers. Final part of the Thesis deals with description of executed experimental measurement with LCCD 2048S-14 type of sensor. Experiments are aimed for statical and dynamical processes. In statical part was checked displaying of fixed objects on CCD sensor in internal spaces on the assumption that changing of object-lens focalization, object´s high and shape. For the evaluation was used of MATLAB program. Dynamical part of measurement is aimed for moving objects.

The diploma thesis is focused to possibility utilizing of optical scanners TRITOP and ATOS for set up geometry of wheels. In background research are described the most important parameters of wheel suspension and devices for measuring these parameters. Practical part is concerned with progression of measurement, results and with determination coordinates of kinematic points. These points are made 3D model of forward and backward suspension wheels. This model helps to make kinematic characteristics and its progression due to attitude of wheel. In last part is described possibility to utilizing of optical scanner ATOS to common measurement of geometry wheels.