Abstract: Offset signals are removed from an incoming x-ray image produced by a large area solid state x-ray detector. A sequence of incoming dark images from the detector, when the detector is not exposed to x-rays, is recursively filtered to generate a low-noise, continuously-updated offset image. This low-noise continuously-updated offset image is stored in an offset image memory. The image in memory is subtracted from the incoming x-ray image to create a corrected image when the detector is exposed to x-rays.

Abstract: In a method for obtaining temporal equity of multiple images for ultrasound imaging equipment, a vector set is determined for each of the multiple images, representative of vectors to be aligned. A plurality of independent weights is then calculated for each image based on the vector sets. The plurality of calculated independent weights is used to determine a firing sequence which provides temporal equity of the multiple images.

Abstract: A strap latch device for securing a medical patient to the side rails of an examining or treatment table includes a pair of extending opposed claw arms, one fixed and the other spring biased to rotate towards the fixed claw arm with the arms overlying a rectangular recess in the latch between the arms. A lever is used to overcome the bias and separate the claw arms so that one edge of a side rail fits into the fixed claw arm and rotation of the latch on the rail projects to the moveable claw arm over the side rail with the side rail fitting closely into the defined recess. Upon release of the bias lever the side rail is grasped by the claw arms with projecting lips on the claw arms securing the rail into its recess. Patient motion and belt tension will tend to accentuate latch retention.

Abstract: An induction motor rotor unit adapted to support and rotate an X-ray target anode in an X-ray tube comprises a stacked array of very thin highly magnetic annular laminations on a cylindrical carrier. Gold plated copper conductor bars are placed in longitudinal coaxial slots in the circumference of the rotor. Gold plated end rings on the carrier abut each end of the stacked array and conductor bars. In a vacuum furnace the gold plating is caused to melt and diffuse into contiguous components to bond the rotor as an integral unit.

Abstract: An x-ray tube having a rotating anode structure which comprises a circular titantium, zirconium, molybdenum alloy target section bonded to a graphite disc. The target section is coated with hefnium carbide as a heat emissivity barrier. The thickness of the barrier is preferably in the range of 4.0-5.0 .mu.m.

Abstract: A method for reducing speckle artifact in an ultrasound image using a two-dimensional median filter having a diamond-shaped five-point kernel. The entire pixel image data is passed through the filter in a manner such that the center point of the kernel is effectively stepped down each range vector in sequence. The magnitudes of the pixel data at each of the five points in the kernel are compared and the value which has the middle magnitude is adopted as a new pixel value, which is substituted for the old pixel value at the center point. After a new filtered vector has been formed from the new pixel values produced at successive center points by stepping down one acoustic vector, the kernel is shifted by one vector and stepped down range again. This process continues through the entire set of vectors until a new set of filtered vectors is formed. This filter will remove speckle holes on the order of one pixel in size while preserving good edge definition.

Abstract: A triangulation method and apparatus for measuring the velocity of a flowing material at a point of interest along two lines of sight which have different vector components. The flow velocity along two different image vectors is measured simultaneously by separately processing the signals from left and right reception apertures (14, 16). In one case, the positions of the reception apertures are held constant and conventional dynamic focussing on receive is used to steer the apertures to follow the transmitted energy as a function of range depth. In an alternative case, the transducers included in each reception aperture are dynamically reassigned in order to maintain a fixed triangulation angle. In this case a reception aperture shifts away from the transmission aperture (12) to track the received backscattered ultrasonic energy at a constant triangulation angle.

Abstract: A stable superconducting switch suitable for use in a conduction-cooled superconducting magnet includes a tape wound in a coil with the tape including an Nb.sub.3 Sn conductor sandwiched between stabilizing layers of copper, bronze or brass and wound in layers, with groups of layers separated by a partial layer of electrically conductive material.

Abstract: A passively shimmed open architecture magnetic resonance imaging magnet utilizing separated superconducting coil assemblies with open space between including apparatus to obtain field homogeneity in the open space by a non-magnetic cylinder in the bore of the magnets for positioning patterns of magnetic shims.

Abstract: The motor efficiency of a rotating X-ray tube having an anode assembly and a cathode assembly, can be greatly improved. The improved efficiency x-ray tube motor comprises a stator and rotor assembly having an air gap between the stator and rotor. The improved efficiency is achieved by reducing the air gap. The stator is operated at anode potential and electrically connected through an anode high voltage cable.

Abstract: A method for estimating the velocity of flow containing a cloud of ultrasound scatterers using time-domain cross-correlation of baseband data. When the scatterers move from one range cell to another between firings, the returning echo signals from adjacent firings will look like time-shifted copies of each other. When the data is basebanded, however, the signals no longer look like time-shifted copies of each other because the baseband process divides the incoming signal into complex quadrature signals. The relative amounts in the real and imaginary parts will be dependent on the relative phase of the incoming signal and the complex mixer, and is therefore range dependent. A scattered signal that may be all real in one firing will have both I and Q components in the next firing when the scatterer has moved by several range cells. This is compensated for by rotating the baseband data for the second firing, prior to cross-correlation, by an angle equivalent to 2 .pi.

Abstract: An apparatus for manufacturing embossed foil for use in controlling the flow of the molten metal tin plating provided in forming laminated tape for use in superconducting magnets utilizing meshing knurling rollers with truncated paramydical elements arranged to provide and embossed pattern for uniform and controlled flow of the tin.

Abstract: A multi-lag method for estimating both high and low velocities of blood flow from a single set of firings in situations where both high-velocity and low-velocity signals are of interest. A color flow processor uses multiple lags in the firing sequence. The normal lag of unity is used for high-velocity estimation; lags greater than unity are used for low-velocity estimation. A normal firing sequence is set up with a pulse repetition frequency that allows accurate velocity estimation of the highest flow velocity that the operator expects. This sequence yields data that is appropriately wall filtered, and a high-velocity estimate is made by correlation over adjacent firings, that is, firings 1 and 2, 2 and 3, 3 and 4, and so on, to the end of the packet, are respectively correlated. The same data is then used to provide a low-velocity estimate. The correlation is calculated between firings that are spaced by multiple units of the pulse repetition interval, e.g.

Abstract: A method for manipulating motion ghosts is disclosed. The method includes acquiring two image data sets, each including a time averaged image component and a ghost component and processing these components to separate the ghosts from the desired image and further using the ghost information to produce a dynamic image. Motion monitoring systems are not required. Improved scan times and noise control are allowed over previous methods.

Abstract: A method for producing dynamic images from a ghosted MR image is disclosed. The method includes acquiring an image data set including a time averaged image component and a ghost component and processing these components to produce a dynamic image. A motion monitoring system is not required as in conventional cine magnetic resonance imaging.

Abstract: A color flow processor has a fuzzy logic processor for determining when an adaptive wall filter can be turned off in response to the condition wherein flow signal will be treated as wall signal. The fuzzy logic processor uses details of wall velocity and power, as well as variance, to determine whether the measured echo signal component to be filtered truly represents the wall velocity only. The general rule applied by the fuzzy logic processor would be that if the wall velocity is LOW and the wall variance is LOW and the wall power is HIGH, than the adaptive filter is turned ON, where LOW and HIGH are fuzzy values. Use can be made of information from previous states, either temporally or spatially, allowing the system to adapt itself to each study or over time.

Abstract: A closed cell polyolefin foam ring member serves as an oil volume expansion compensator in a high voltage electrical cable connector of an X-ray tube in which a supply of oil expands under high temperature and compresses the ring for an increase in volume for the expanding oil.

Abstract: A rotating anode target for X-ray devices comprises a circular graphite disc structure both of whose front and back sides or faces taper equally towards each other and define a narrow rim surface and central hub section. A larger area of the front face is coated with a focal track metal which extends coextensively over the front face to overlap part of the rim surface. The slant height dimension of the focal track metal is greater than the diameter of the hub section.