نتایج جستجو برای: beam gantry
تعداد نتایج: 114050 فیلتر نتایج به سال:
Abstract—This paper proposed a nonlinear model predictive control (MPC) method for the control of gantry crane. One of the main motivations to apply MPC to control gantry crane is based on its ability to handle control constraints for multivariable systems. A pre-compensator is constructed to compensate the input nonlinearity (nonsymmetric dead zone with saturation) by using its inverse functio...
A major factor affecting fresh pork quality is the implementation of management technologies that improve swine movement at the time of loading. Two experiments were conducted to evaluate the effects of the loading system at the farm (traditional chute T vs. prototype loading gantry P) on the quality attributes of fresh pork loins. Two marketing groups were utilised. Experiment 1 used 100 pig l...
A method is presented for extraction of intra and inter fraction motion of seeds/markers within the patient from cone beam CT (CBCT) projection images. The position of the marker is determined on each projection image and fitted to a function describing the projection of a fixed point onto the imaging panel at different gantry angles. The fitted parameters provide the mean marker position with ...
BACKGROUND Carbon fiber (CF) is now the material of choice for radiation therapy couch tops. Initial designs included side metal bars for rigidity; however, with the advent of IGRT, involving on board imaging, new thicker CF couch tops without metal bars have been developed. The new design allows for excellent imaging at the expense of potentially unacceptable dose attenuation and perturbation....
PURPOSE To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. METHOD AND MATERIALS The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6...
Four-dimensional computed tomography (4D CT) is a dynamic volume imaging system of moving organs with an image quality comparable to that of conventional CT. 4D CT will be realized by several technical breakthroughs for dynamic cone-beam CT: (1) a large-area two-dimensional (2D) detector; (2) high-speed data transfer system; (3) reconstruction algorithms; (4) ultra-high-speed reconstruction com...
no 1: Technical challenges of fast volumetric rescanning O. Actis, D. Meer, A. Mayor, G. Klimpki, S. Psoroulas, D.C. Weber For pencil beam scanning the most studied method to mitigate the dose delivery uncertainties due to the organ motion is rescanning. Achieving an optimal treatment for a moving target by volumetric rescanning, where the whole tumour volume is scanned multiple times, requires...
Transshipment yards, where gantry cranes allow for an e cient transshipment of containers between di erent freight trains, are important entities in modern railway systems and facilitate the general shift from point-to-point transport to hub-and-spoke railway systems. Modern rail-rail transshipment yards accelerate container handling, so that multiple smaller trains with equal destination can b...
To investigate the effects of sagging shifts of three on-board kV imaging systems (OBI) on the isocenter positioning accuracy and image quality of cone-beam CT (CBCT). A cubical phantom having a metal marker in the center that can be aligned with the radiation isocenter was used to measure sagging shifts and their variation with gantry angle on three Varian linacs with kV on-board imaging syste...
BACKGROUND Intraoperative Radiotherapy (IORT) is a method by which a critical radiation dose is delivered to the tumour bed immediately after surgical excision. It is being investigated whether a single high dose of radiation will impart the same clinical benefit as a standard course of external beam therapy. Our centre has four Photon Radiosurgery Systems (PRS) currently used to irradiate brea...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید