Abstract: An apparatus has a patient support, a rotatable gantry supporting a source of imaging radiation, and a radiation detector that operates in a cyclical pattern of an exposure phase followed by a readout phase. For a first detector cycle in which the gantry has a first angle of rotation, the source of radiation is controlled to emit a first radiation beam pulse during the exposure phase, and respective first imaging data is read out during the readout phase. For a second, subsequent detector cycle, it is determined if the gantry has rotated through at least a threshold angular displacement relative to said first angle of rotation, and if so, the source of radiation is controlled to emit a second radiation beam pulse during the exposure phase, and respective second imaging data is read out during the readout phase.

Abstract: In various embodiments, a system for controlling radiotherapy equipment in a treatment environment includes a controller for receiving, from one or more image capture devices, data indicating the position of one or more objects in the treatment environment. Based on the position data, the controller defines one or more exclusionary zones from which the radiotherapy equipment is excluded. Each zone has a buffer area surrounding one or more of the objects. The controller further directs the radiotherapy equipment such that a radiotherapy treatment plan is delivered without the equipment entering into the exclusionary zones.

Abstract: In radiotherapy apparatus comprising an imager for the MV beam and a separate kV imaging system, it is common for there to be significant artefacts in the kV image arising from the MV pulse. We disclose such a radiotherapy apparatus which is adapted to (i) cause the therapeutic source to emit radiation while keeping the diagnostic source inactive, (ii) read an image from the detector associated with the therapeutic source, (iii) cause the diagnostic source to emit radiation and while keeping the therapeutic source inactive, (iv) read an image from the detector associated with the diagnostic source, and (v) repeat as necessary. The control unit is preferably adapted to, at steps (ii) and (iv), read an image from both of the detectors, or to clear the “inactive” detector. The detectors are ideally flat-panel detectors, capturing a two-dimensional image.

Abstract: For Respiration Correlated Cone Beam CT scanning, we have observed that improvements in the frame rate are in fact undesirable. We therefore propose a radiographic apparatus comprising a beam of radiation and a detector therefor, adapted to obtain a two dimensional image of the beam after passing through a cyclically varying object to be investigated, a processor adapted to review the images and select images at like points in the cycle, and a control means for the beam of radiation adapted to activate the beam periodically. The control means can activate the beam at a frequency of between 0.5 and 5 Hertz, more preferably between 1 and 3 Hertz, which corresponds (roughly) to a frequency that is between 6 and 10 times the frequency of the cyclical variation. It will assist if the selected point of the cycle is an extremity thereof, as the rate of change in these areas is at a minimum. Thus, slight mismatches between the two cycles will then have only a small effect.

Abstract: For Respiration Correlated Cone Beam CT scanning, we have observed that improvements in the frame rate are in fact undesirable. We therefore propose a radiographic apparatus comprising a beam of radiation and a detector therefor, adapted to obtain a two dimensional image of the beam after passing through a cyclically varying object to be investigated, a processor adapted to review the images and select images at like points in the cycle, and a control means for the beam of radiation adapted to activate the beam periodically. The control means can activate the beam at a frequency of between 0.5 and 5 Hertz, more preferably between 1 and 3 Hertz, which corresponds (roughly) to a frequency that is between 6 and 10 times the frequency of the cyclical variation. It will assist if the selected point of the cycle is an extremity thereof, as the rate of change in these areas is at a minimum. Thus, slight mismatches between the two cycles will then have only a small effect.

Abstract: A system and method for dynamically generating Web content using a parse tree is described. A template describing a dynamically generated Web page is built. The template includes a script written in a tag-delimited page description language. One or more markers included within the template each indicate a relative location within the Web page for dynamic content insertion. The hierarchical nature of the page description language is used to infer a set of display regions, which are referenced by a parse tree. The parse tree includes a plurality of nodes structured into levels. Each node corresponds to structural tags specified within the script. Each successive level represents a further nesting of the structural tags within the script. A controller program invokes a document engine and specifies a particular template. Each marker may be substituted with dynamic content zero, one or several times each.