Abstract:
A universal radiographic/fluoroscopic room includes a digital imaging platform adapted to occupy operating and non-operating positions. A park function automatically moves the digital imaging platform between the operating and non-operating positions without requiring operator effort. The digital imaging platform has local and remote control panels having substantially duplicate functions. The remote control panel allows the operator to control operation of the digital imaging platform from a location shielded from X-ray exposure. Methods and apparatus are provided to ensure safe, predictable, and consistent operation from all control panels. The operator selects any available operating mode, including auto-bucky, auto-wall, auto-table, auto-table/wall, servo-tomo, conventional stepping, stepped-digital, auto-step, and auto-step-center modes, using a control panel. The control system automatically determines which system components are required to perform that type of examination, moves the components into operational or storage positions as required, and prepares each component for operation.
Abstract:
A universal radiographic/fluoroscopic "room" is constructed according to the present invention by combining a versatile group of X-ray examination system components, electrical and mechanical drive components, and sensing components, under the supervision of a flexible control system, to form a universal diagnostic medical imaging system capable of performing radiographic, fluoroscopic, tomographic, and stepped examinations in several different operator-selectable configurations. The operator selects any available operating mode, including auto-bucky, auto-wall, auto-table, auto-table/wall, servo-tomo, conventional stepping, stepped-digital, auto-step, and auto-step-center modes, using a a control panel. The control system automatically determines which system components are required to perform that type of examination, moves the components into operational or storage positions as required, and prepares each component for operation. The operator need not manually reconfigure the equipment. In "stepped-digital" modes useful for peripheral angiography, an under-table X-ray tube and over-table image intensifier execute a series of radiographic exposures at preselected locations. The digital imaging platform is moved while the patient remains stationary. This reduces motion artifacts. For each step, a test fluoroscopic exposure is performed under automatic brightness control to determine an optimum technique. The technique so determined is converted for use in a subsequent radiographic exposure. The operator observes the flow of the contrast medium during the test fluoroscopic exposure and commands the radiographic exposure when the contrast medium arrives at the desired position in the image. Alternatively, the control system may detect the presence of the contrast medium in the image by comparing a change in image contrast with a previously observed threshold change.
Abstract:
A speed control apparatus for determining and controlling the speed of rotation of a rotor in an AC motor. The motor includes a stator having main and auxiliary windings. Main and auxiliary winding controllers control the operational input signals supplied to the main and auxiliary windings by a signal generator. A pulse generator is connected to the main winding for providing a test pulse during a speed measurement operation. The test pulse magnetizes a portion of the rotor which induces a feedback EMF signal in the auxiliary winding. A feedback sensor circuit receives the feedback signal and forwards it to a microprocessor. The microprocessor calculates the rotational speed of the rotor based on the feedback signal.
Abstract:
A universal radiographic apparatus that allows an operator to select between conventional radiographic mode and linear tomographic mode. In conventional radiographic mode of operation, several automatic modes are provided. An x-ray tube mounted to a tube crane positioned above an elevating table can be accurately controlled in longitudinal and vertical movement, as well as in x-ray tube angulation. In linear tomographic mode, a table bucky is moved laterally in opposition to movement of the tube crane, with angulation keeping the tube aimed at the bucky. In conventional radiographic mode, the system supports an auto bucky mode, where the table bucky automatically tracks tubecrane motion, or an auto table mode, where the tube crane tracks table vertical motion to maintain a fixed SID. In an auto wall mode, the tube crane tracks vertical movement of an associated wall bucky.
Abstract:
A radiographic/fluoroscopic imaging system provides rapid transition from fluoroscopic to radiographic imaging mode by maintaining the X-ray tube high voltage, increasing the filament current, allowing X-ray tube current to increase toward the desired radiographic current, and terminating exposure when the desired X-ray dose has been achieved. Rapid transition from radiographic to fluoroscopic imaging mode is provided by reducing x-ray tube high voltage to produce an equivalent fluoroscopic-level x-ray output at high initial current, dropping filament current, and enabling ABS control of the high-voltage. As x-ray tube current drops, ABS correspondingly increase high voltage to maintain the desired output. The imaging system obtains movement-related information by analyzing a video signal (such as from fluoroscopic image or an image from an optical camera trained on the patient), or from operator movement requests. The imaging system uses movement-related information to responsively control fluoroscopic pulse rate or other imaging parameters. The imaging system can also use such information to initiate a radiographic exposure, or advance to the next step of an operator programmed examination consisting of interspersed fluoroscopic and radiographic exposures. This results in a lower dose to both the patient and the examiner, consistent with high image quality.
Abstract:
A universal radiographic/fluoroscopic "room" is constructed according to the present invention by combining a versatile group of X-ray examination system components, electrical and mechanical drive components, and sensing components, under the supervision of a flexible control system, to form a universal diagnostic medical imaging system capable of performing radiographic, fluoroscopic, tomographic, and stepped examinations in several different operator-selectable configurations. The operator selects any available operating mode, including auto-bucky, auto-wall, auto-table, auto-table/wall, servo-tomo, conventional stepping, stepped-digital, auto-step, and auto-step-center modes, using a a control panel. The control system automatically determines which system components are required to perform that type of examination, moves the components into operational or storage positions as required, and prepares each component for operation. The operator need not manually reconfigure the equipment. In "stepped-digital" modes useful for peripheral angiography, an under-table X-ray tube and over-table image intensifier execute a series of radiographic exposures at preselected locations. The digital imaging platform is moved while the patient remains stationary. This reduces motion artifacts. For each step, a test fluoroscopic exposure is performed under automatic brightness control to determine an optimum technique. The technique so determined is converted for use in a subsequent radiographic exposure. The operator observes the flow of the contrast medium during the test fluoroscopic exposure and commands the radiographic exposure when the contrast medium arrives at the desired position in the image. Alternatively, the control system may detect the presence of the contrast medium in the image by comparing a change in image contrast with a previously observed threshold change.
Abstract:
A method for controlling output of an x-ray source to optimize x-ray energy arriving at an associated x-ray receptor during linear tomographic examination. The method comprises the steps of selecting tomographic sweep parameters, predicting a set of x-ray source control parameters based, at least in part, upon the selected tomographic sweep parameters, and controlling x-ray source output in accordance with the set of x-ray source control parameters to optimize x-ray energy arriving at the associated x-ray receptor. Apparatus for controlling output of an x-ray source is also disclosed.
Abstract:
An exposure control system for radiographic, fluoroscopic, or other diagnostic imaging includes an exposure sensor array and a control element. The exposure sensor array has a plurality of sensor elements directed to defined locations uniformly distributed over the imaging field and may make direct or indirect measurements of exposure rate or imaging converter brightness. A structure or region of diagnostic interest to examining personnel is identified, and only sensors which correspond to locations within the area of interest are selected for use in exposure control. Predefined examination parameters suitable for particular anatomical patient regions are stored. Upon request by examining personnel to perform an examination of an anatomical patient region, the parameters are retrieved for use. The parameters include a preselection of sensors typically suitable for examinations of such region. The sensor locations, and their selection status, may be displayed as an overlay on an actual diagnostic image so that examining personnel may determine which sensors correspond to a structure or region of diagnostic interest. Examining personnel may manually select or deselect sensors. During an automatic mode examination, sensor outputs are analyzed and sensors providing apparently spurious outputs are deselected.
Abstract:
A radiographic/fluoroscopic imaging system provides rapid transition from fluoroscopic to radiographic imaging mode by maintaining the X-ray tube high voltage, increasing the filament current, allowing X-ray tube current to increase toward the desired radiographic current, and terminating exposure when the desired X-ray dose has been achieved. Rapid transition from radiographic to fluoroscopic imaging mode is provided by reducing x-ray tube high voltage to produce an equivalent fluoroscopic-level x-ray output at high initial current, dropping filament current, and enabling ABS control of the high-voltage. As x-ray tube current drops, ABS correspondingly increase high voltage to maintain the desired output. The imaging system obtains movement-related information by analyzing a video signal (such as from fluoroscopic image or an image from an optical camera trained on the patient), or from operator movement requests. The imaging system uses movement-related information to responsively control fluoroscopic pulse rate or other imaging parameters. The imaging system can also use such information to initiate a radiographic exposure, or advance to the next step of an operator programmed examination consisting of interspersed fluoroscopic and radiographic exposures. This results in a lower dose to both the patient and the examiner, consistent with high image quality.
Abstract:
A universal radiographic/fluoroscopic "room" is constructed according to the present invention by combining a versatile group of X-ray examination system components, electrical and mechanical drive components, and sensing components, under the supervision of a flexible control system, to form a universal diagnostic medical imaging system capable of performing radiographic, fluoroscopic, tomographic, and stepped examinations in several different operator-selectable configurations. The operator selects any available operating mode, including auto-bucky, auto-wall, auto-table, auto-table/wall, servo-tomo, conventional stepping, stepped-digital, auto-step, and auto-step-center modes, using a control panel. The control system automatically determines which system components are required to perform that type of examination, moves the components into operational or storage positions as required, and prepares each component for operation. The operator need not manually reconfigure the equipment. In "stepped-digital" modes useful for peripheral angiography, an under-table X-ray tube and over-table image intensifier execute a series of radiographic exposures at preselected locations. The digital imaging platform is moved while the patient remains stationary. This reduces motion artifacts. For each step, a test fluoroscopic exposure is performed under automatic brightness control to determine an optimum technique. The technique so determined is converted for use in a subsequent radiographic exposure. The operator observes the flow of the contrast medium during the test fluoroscopic exposure and commands the radiographic exposure when the contrast medium arrives at the desired position in the image. Alternatively, the control system may detect the presence of the contrast medium in the image by comparing a change in image contrast with a previously observed threshold change.