Abstract: A system and method are provided for monitoring engine thrust bearing temperature deviations. Initially, key engine parameters are measured. A bearing temperature rise can be predicted based on the measured parameters. The predicted rise value is compared with the actual rise value to generate a comparison value. The system is trained to respond to the comparison value to prevent catastrophic failure.

Abstract: A frangible cover is provided for a recess in a containment case for turbofan engine blade removal and access. The recess provided in the containment case allows outward radial movement of the engine fan blade when the engine fan blade is to be removed from the containment case. The present invention proposes a frangible component to cover the recess. A plurality of initiation points, notched in the frangible cover at intersections of surfaces encourages brittle fracture of the frangible component.

Abstract: A method is used for interfacing materials of dissimilar thermal expansion in an X-ray tube. Initially, a first joint is identified, which has an inner component to be received into an outer component. Typically, the inner component has a higher coefficient of expansion than the outer component, so the purpose of the invention is to reduce the physical expansion of that component in the joint. A plurality of slots is introduced along the approximate axial length of the inner component of the joint, to achieve the aforementioned purpose. Alternatively, a coupling member could be provided between two components, the coupling member having a thermal expansion rate greater than one component and less than the other component.

Abstract: A method is used for interfacing materials of dissimilar thermal expansion in an X-ray tube. Initially, a first joint is identified, which has a first component to be received into a second component. Typically, the first component has a higher coefficient of expansion than the second component, so the purpose of the invention is to reduce the physical expansion of that component in the joint. A plurality of slots is introduced along the approximate axial length of a coupling member at the joint, to achieve the aforementioned purpose. The coupling member is provided between the two components, and has a thermal expansion rate greater than one component and less than the other component.

Abstract: In an X-ray tube target, a shaft is welded to the anode target, the shaft typically being TZM or a molybdenum alloy. This defines a first weld location and creates an integral shaft-target assembly. The shaft-target assembly is then machined. A heat sink material, such as graphite, is brazed to the integral shaft-target assembly. A hub is then welded to the shaft, at an end opposite the target, defining a second weld location and creating a hub-target assembly. The hub can be columbium or columbium alloy. Subsequently, the hub-target assembly can be machined. Having a dual weld procedure, and eliminating the subsequent brazing step to join the hub to the shaft, enables the alloys to maintain their high strength without annealing, thereby allowing the shaft materials to keep their high strength and reducing plastic deformation at the lower (hub) portion of the shaft.

Abstract: A method is provided for maximizing substrate usage in the fabrication of flat panel displays or detectors, while also maximizing electrostatic protection for the displays or detectors. Initially, at least two detectors are positioned on the substrate, with each of the detectors having a guard ring of a certain width. At least a section of the guard ring width of one detector is approximately adjacent to a section of the guard ring width of another detector. The approximately adjacent guard ring width sections are then positioned such that a maximum overlap of the adjacent guard ring width sections is achieved, while still providing each display or detector with electrostatic discharge protection. Each of the detectors is separated from the other detectors and the remainder of the substrate by the process of scribing partially through the substrate and breaking at the scribe mark or by sawing.

Abstract: The present invention provides for an adherent and durable coating for a lead-lined x-ray tube casing which is exposed to dielectric cooling oil. Electroplating lead radiation shield material with a corrosion resistant and nontoxic material having excellent solderability, softness and ductility, provides a clean corrosion resistant surface which is inert to the oil, independent of temperature and x-ray irradiation. The electroplating material preserves the lead surface from flaking and corroding to the oil. The electroplating material is preferably selected from the group consisting of tin, silver, copper and nickel, or various combinations of those or other materials capable of providing an adherent and durable coating for the x-ray tube casing.

Abstract: An X-ray tube comprises an anode assembly having an associated anode and a cathode assembly for providing a focused electron beam directed to the anode. An anode target, associated with the anode assembly, accelerates the electron beam and produces X-rays upon electron impact with the anode target. Off-focal radiation tends to be most intensely emitted by the top surface of the target. In conventional X-ray tubes, the off-focal radiation as seen by the detector encompasses almost the entire top surface of the target assembly. In accordance with the present invention, the anode target comprises a cut-out top surface for reducing off-focal radiation, by blocking the off-focal radiation from the top surface from reaching the detector. Blocking the radiation produced at the top surface becomes more important as the ratio of the track area visible at the detector decreases with respect to the top surface area.

Abstract: A method is provided for measuring the weight of a medical imaging scanner patient. The scanner has a bore portion for receiving and housing the patient during a scan. Initially, a reclining apparatus associated with the scanner is provided, on which the patient can recline during the scan. A hydraulic lift mechanism is then used to position the reclining apparatus and the patient at bore level. The pressure within the hydraulic lift mechanism can then be measured as a function of downward force exerted by the reclining apparatus and the patient surface. Alternatively, the automatic measuring of patient mass, associated with the movement of the reclining apparatus and patient into the bore, can be determined by calculating instantaneous acceleration of the reclining apparatus and patient as the reclining apparatus and patient are slid into the bore.

Abstract: In a mobile magnetic resonance imaging van, the challenge is to design a magnet mounting system such that the top and bottom poles of the magnet are within magnet temperature gradient specifications for good image quality. The present invention provides such a mounting system and method for mounting a permanent magnet in a mobile trailer vehicle. Mounting bolts are used to mount the permanent magnet to the floor of the mobile trailer vehicle. Laminate or composite insulating material, preferably stacked Phenolic pads, thermally insulate the permanent magnet from the trailer floor. A second set of stacked insulating material pads thermally insulate the mounting bolts from the permanent magnet.

Abstract: A rotating anode structure for an X-ray tube is provided, having a lightweight target anode. A carbon-carbon composite target substrate has constituents and weave geometries. A refractory metal focal track layer is deposited on the substrate to produce X-rays. An interlayer is disposed between the focal track layer and the substrate to relieve thermal expansion mismatch stresses between the carbon-carbon composite anode target substrate and the refractory metal focal track layer. The interlayer is a rhenium interlayer and the focal track layer is typically a tungsten-rhenium focal track layer.

Abstract: An image quality test phantom tool is provided for use in the calibration and standardization of digital x-ray fluoroscopy and radiography systems. A composite phantom has a base for providing mechanical stability, a mesh with a central cut-out overlaid on the base, inserts positioned in the cut-out, and a carrier for housing the composite phantom. A digital image of the phantom is processed to compute x-ray system image quality measurements.

Abstract: A method for assembling a rotating X-ray tube structure ensures balance retention during the life of the tube. The X-ray tube structure has a cathode for emitting electrons, and a rotor and a bearing assembly for facilitating rotation of an anode. At least one joint is identified in the X-ray tube structure and interference fit assembly is used to eliminate shifts at the joint. The interference fit assembly is particularly advantageous for eliminating even the minutest shifts in the main joints of the anode assembly. Interference fit assembly can be applied between the rotor and the anode target to provide a first joint having balance retention; and interference fit assembly can be applied between the bearing assembly and the rotor to provide a second joint having balance retention.

Abstract: A method is used for interfacing dissimilar materials in an X-ray tube. The X-ray tube includes a rotor assembly to distribute heat generated in the X-ray tube. The X-ray tube is sealed within a glass material which has a first expansion coefficient. An interface is provided between the rotor assembly and the glass material to absorb temperature coefficient stresses. Preferably, the glass material is Borosilicate and the interface comprises a metal material and a ceramic material. The ceramic material has a second expansion coefficient that closely matches the first expansion coefficient. The metal material is preferably Kovar, and the ceramic material is preferably Mullite. Temperature coefficient stresses are then absorbed within the ceramic and metal structure.

Abstract: A method and system are provided for controlling a motor to rapidly accelerate and synchronize with an external synchronization pulse. First, the motor is accelerated to only half of the desired speed. At this point, the phase error with the sync pulse is calculated, and the motor continues "cruising" at half speed until the phase discrepancy diminishes. Then the motor rises to the full desired speed at the optimal time such that it is in phase with the sync pulse just as it reaches full speed. The acceleration is performed at a constant, yet slow enough, rate to receive at least three speed feedbacks. Then the instantaneous speed can be accurately measured and the next (and final) speed command during acceleration is interpolated between the ideal command for rising and the ideal command for cruising at the desired speed.

Abstract: A method for identifying and correcting bad pixels in an x-ray image produced by a large area solid state x-ray detector is disclosed. Initially, each bad pixel is identified. An appropriate correction scheme is then selected from a predetermined list. A correction code is then assigned to each bad pixel, the correction code corresponding to the selected correction scheme. The correction code is stored in a pixel-correction memory, and the correction code for each pixel is read during imaging. Finally, each bad pixel value found during the correction code reading is replaced using the selected correction scheme, and can be immediately displayed.

Abstract: A method is used to bond dissimilar metals, such as for an x-ray tube. Copper and steel tubular components are provided. An interlayer material situated between the metal layers is used to bond the copper and steel tubular components by solid state diffusion process. The interlayer material may be pure nickel, pure copper, or a layered combination of nickel and copper or copper alloy. The use of the low cost interlayer material and the solid state diffusion process yields a strong bond between the dissimilar metals.

Abstract: A rotating X-ray tube comprises a cathode assembly including a cathode and a cathode current supply, and an anode assembly having an anode current controlled via the cathode current supply. A filament for emitting electrons is separated from the cathode. A cathode cup supports the filament and provides electron field shaping assistance. The X-ray tube further comprises a distributed capacitance for affecting the cathode cup electron field, and an insulator leakage resistance. The cathode cup is allowed to float on the insulator leakage resistance, whereby voltage associated with the distributed capacitance and the leakage resistance is allowed to remain relatively constant.

Abstract: A transmit power supply optimization method optimizes power supply voltage to high voltage transmitters of an ultrasound imaging apparatus for each operating mode of the apparatus. The method comprises the steps of linking the operating mode of the apparatus, the output of the high voltage transmitters, and the power supply. It is then determined when a change in optimum power supply voltage will be desired. Operation of the high voltage transmitter power supply and the high voltage transmitters is coordinated to react to the determination that a change in optimum power supply voltage will be desired, before the change in optimum power supply voltage is actually desired. Finally, a distributed power supply filter is provided to allow the high voltage transmitters to operate while the change in optimum power supply voltage is occurring.

Abstract: Row variable offsets in a large area solid state x-ray detector are compensated for. Initially, a calibration is performed to determine the row variable offsets. The calibration is achieved by measuring the average offset of each row. During normal operation, this offset is compensated for in a converting circuit. The required signal range of the converting circuit is consequently reduced.