Abstract: A method and system are disclosed for estimating internal position information of a target in real-time based on a single gantry-mounted x-ray imager and a respiratory signal. The x-ray imaging is done periodically to limit radiation dosage. Initial parameters for the estimation model are determined in a pre-treatment session using four dimensional computed tomography (4D CT) in combination with a respiratory signal acquired from the patient. The model parameters are updated during treatment based on the periodic x-ray image data and the respiratory signal.

Abstract: Improved 4D imaging reconstruction is provided for a freely breathing patient. 3D patient images from an imaging dataset are binned according to respiratory displacement or phase. The bins are defined by ranges, so every image in the raw 3D data set is included in a bin. Since binning in this manner often results in two or more images per bin, the 4D reconstruction is determined by selecting one 3D image from each bin at each patient position. This selection is performed so as to maximize the anatomical similarity of 3D images at adjacent patient positions. In cases where the 3D images include multiple slices, a 2D comparison of the closest slices can be used to determine anatomical similarity of the 3D images.

Abstract: Improved 4D imaging reconstruction is provided for a freely breathing patient. 3D patient images from an imaging dataset are binned according to respiratory displacement or phase. The bins are defined by ranges, so every image in the raw 3D data set is included in a bin. Since binning in this manner often results in two or more images per bin, the 4D reconstruction is determined by selecting one 3D image from each bin at each patient position. This selection is performed so as to maximize the anatomical similarity of 3D images at adjacent patient positions. In cases where the 3D images include multiple slices, a 2D comparison of the closest slices can be used to determine anatomical similarity of the 3D images.

Abstract: A method and system are disclosed for estimating internal position information of a target in real-time based on a single gantry-mounted x-ray imager and a respiratory signal. The x-ray imaging is done periodically to limit radiation dosage. Initial parameters for the estimation model are determined in a pre-treatment session using four dimensional computed tomography (4D CT) in combination with a respiratory signal acquired from the patient. The model parameters are updated during treatment based on the periodic x-ray image data and the respiratory signal.

Abstract: The density of the lung of a patient suffering from pulmonary edema is monitored by irradiating the lung by a single collimated beam of monochromatic photons and measuring the energies of photons Compton backscattered from the lung by a single high-resolution, high-purity germanium detector. A compact system geometry and a unique data extraction scheme are utilized to monimize systematic errors due to the presence of the chestwall and multiple scattering.

Abstract: An inertial trap and grooved impactor for providing a sharp cutoff for particles over 15 microns from entering an inhalable particulate sampler. The impactor head has a tapered surface and is provided with V-shaped grooves. The tapered surface functions for reducing particle blow-off or reentrainment while the grooves prevent particle bounce. Water droplets and any resuspended material over the 15 micron size are collected by the inertial trap and deposited in a reservoir associated with the impactor.

Abstract: A vessel system (10) comprises an outer shell (14) of carbon fibers held in a binder, a coolant circulation mechanism (16) and control mechanism (42) and an inner shell (46) comprised of a refractory material and is of light weight and capable of withstanding the extreme temperature and pressure environment of, for example, a coal gasification process. The control mechanism (42) can be computer controlled and can be used to monitor and modulate the coolant which is provided through the circulation mechanism (16) for cooling and protecting the carbon fiber and outer shell (14). The control mechanism (42) is also used to locate any isolated hot spots which may occur through the local disintegration of the inner refractory shell (46).

Abstract: Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor (11) for separating an inlet flow (Q.sub.O) having particulate contaminants into a coarse particle flow (Q.sub.1) and a fine particle flow (Q.sub.2) to enable collection of such particles on different filters (19a, 19b) for separate analysis. An inlet particle acceleration nozzle (28) and coarse particle collection probe member (37) having a virtual impaction opening (41) are aligned along a single axis (13) and spaced apart to define a flow separation region (14) at which the fine particle flow (Q.sub.2) is drawn radially outward into a chamber (21) while the coarse particle flow (Q.sub.1) enters the virtual impaction opening (41). Symmetrical outlet means (47) for the chamber (21) provide flow symmetry at the separation region (14) to assure precise separation of particles about a cutpoint size and to minimize losses by wall impaction and gravitational settling.