Abstract: Apparatus is disclosed for providing electrical energy to orbital components of a computed tomography (CT) scanning unit. The apparatus includes a number of high voltage slip rings immersed in an insulating dielectric material. Each slip ring contacts a stationary brush biased to contact the slip ring to insure maintenance of a low resistance path between a stationary source of high potential and a cathode and anode pair of an orbital X-ray tube. A number of low voltage slip rings are further included to facilitate transmission of low voltages to other orbital components of the CT unit. The apparatus is of a compact light-weight design and is mounted to tilt certain components about an axis which intersects a patient's torso to provide CT scanning flexibility.

Abstract: An oil filled high voltage connector assembly, such as the type used to connect high voltage X-ray apparatus cables, which includes an internally located oil expansion chamber. A female connector defines a cylindrical container closed at one end and has an outward extending flange. An annulus having a hollowed out cavity on one surface is covered with an elastomeric material in contact with the flange. A liquid dielectric between the female connector and a male connector presses against the elastomeric material and can push the elastomeric material into the cavity when it expands.

Abstract: An x-ray tube voltage generator with automatic stabilization circuitry is disclosed. The generator includes a source of pulsating direct current voltage such as from a rectified 3 phase transformer. This pulsating voltage is supplied to the cathode and anode of an x-ray tube and forms an accelerating potential for electrons within that tube. The accelerating potential is stabilized with a feedback signal which is provided by a feedback network. The network includes an error signal generator which compares an instantaneous accelerating potential with a preferred reference accelerating potential and generates an error function. This error function is transmitted to a control tube grid which in turn causes the voltage difference between x-ray tube cathode and anode to stabilize and thereby reduce the error function. In this way stabilized accelerating potentials are realized and uniform x-ray energy distributions produced.

Abstract: An improved semiconductor gamma camera is disclosed. The gamma camera includes a p-i-n semiconductor diode which detects the presence and energy of gamma radiation from a source. Typically the source is radioactive material in a patient organ which is detected and then interpreted by a doctor while diagnosing the condition of that organ. The detector includes an improved electrical connection technique to allow the p-i-n diode to be connected to electronic circuitry necessary to provide spatial and energy information. In the improved camera first a passivation layer is deposited on both faces of the p-i-n diode and then a resistive layer is applied to form a reliable easily reproduced electrical contact to the junction. These two layers in combination prevent foreign matter from contacting the semiconductor material comprising the detector while providing interconnection to the electronic circuitry.

Abstract: An electronically step scanned real time ultrasonic imaging system and method is disclosed. The system includes a transducer assembly having an array of elements, each with an axis of transmission along which it transmits its main ultrasonic energy when electrically stimulated. The elements are disposed in a curvilinear array, wherein their axes of transmission are approximately coplanar, but divergent in the common plane. This configuration provides a relatively large scanned area without need for either electronic or mechanical sector scanning techniques to steer the incident ultrasonic energy over a large angle.

Abstract: A masking apparatus and palpitator cone drive system for an X-ray spotfilming device. The masking apparatus comprises first and second pairs of shutter-like members mounted for reciprocating movement in two mutually orthogonal directions. Each mask member of the second pair includes first and second relatively moveable elements that operate in a telescope-like manner. A drive system including a reversible motor and a feedback potentiometer actuates the elements at first and second speeds so that the elements reach their retracted and extended positions simultaneously. The cone drive system includes a drive motor, a drive belt and drive assembly for driving the cone between retracted and operative positions. A cone lock is engageable with a keeper located at a cone-advanced position of the drive assembly and is released by the drive belt whenever the drive motor is energized in the cone-retracting direction.

Abstract: An X-ray spot filmer is disclosed including a system for cyclically shifting a grid assembly interposed between an X-ray source and a film cassette. The system comprises an electrically energizable grid assembly actuator and an actuator controller for energizing the actuator to cyclically shift the grid assembly. The actuator controller includes actuator energizing output circuitry effective to govern the direction and speed of operation of the actuator in response to a control signal and control signal generator circuitry for producing control signals effective to govern operation of the output circuitry including an oscillator for producing a cyclically varying control signal which causes cyclic grid assembly shifting.

Abstract: A radiation absorption shield assembly is disclosed for controlling the configuration of the radiation sensitive field of a radiation detecting camera. The shield assembly includes a first annular lead shield element defining a first aperture and mounted to the camera for blocking out a fixed field of radiation. The assembly also includes a second annular lead shield element in series with the first which defines a second aperture movable with respect to the first aperture. Attached to and in a spaced parallel relation with the first shield element is a circular radiation transparent disk which defines a thin gap to accommodate the second shield element. The second shield element is slidably adjustable within the gap, transverse to the first element, by one conducting a radiation study, to vary the configuration of a region of interest defining a field area through which radiation can pass from the patient for detection by the camera.

Abstract: An X-ray spotfilming apparatus including a film cassette carriage mounted for longitudinal, reciprocating motion in housing having at least one film cassette receiving opening. A carriage drive system including a servomotor and a feedback potentiometer is operative to drive the film carriage between a retracted position and a plurality of exposure positions. Clamp members are mounted for sliding transverse movement within the carriage assembly and are operative in connection with a clamp coupling mechanism and clamp drive system to effect both clamping and translational movements within the carriage. A cassette advance apparatus drives a film cassette to a predetermined position along a clamp members and includes a advance pawl engageable with the cassette and a feedback pot for monitoring the position of the pawl. The feedbck signals from the clamp drive and cassette advance potentiometers are utilized to determine the longitudinal and transverse dimensions of the film cassette.

Abstract: Method and apparatus in an x-ray image intensifier tube 22. The invention features an intensifier tube including a photo cathode 24 for generating photoelectrons and a screen 25 for receiving those electrons after they have been accelerated through the length of the intensifier tube. A metallic shield or housing 27, 28, 29 is positioned about the space between photo cathode 24 and screen 25 and a multiturn conductive wire or coil 30 is positioned about the exterior surface of the shield and connected to a source of potential 23. The current through the wire is governed to cancel uniformly the earth's natural geomagnetic field throughout the entire interior region of the evacuated tube. This step reduces image degradation due to forces on the electron as they travel from the photocathode to the screen. Circuitry 38 is included for changing the current as the intensifier tube is re-oriented in the earth's field during x-ray diagnostic procedures.

Abstract: The inner surface of an X-ray tube envelope is constructed to prevent the build-up of an electrically conductive layer of metal deposits on the tube envelope in the regions adjacent to and between the cathode focusing element and the anode. In the disclosed embodiment this area is textured so that metal deposits can only collect in certain places and not in others. The places of metal collection are spaced so that the development of a conductive metal layer is inhibited. By properly texturing the inner surface of the envelope, this spaced collection of metal is so effective that the spaced regions of metal build-up are electrically insulated from one another. A method is disclosed comprising first mechanically abrading the inner surface of the envelope to create small fracture regions. Thereafter, the abraded surface is acid-etched. The acid attacks the areas of the envelope which exhibits these fracture regions creating relatively deep and narrow "canyons" surrounding "islands".

Abstract: An X-ray apparatus which is readily convertible for conventional radiographic or tomographic operation includes an X-ray source and an imaging device movably supported on opposite sides of a patient support. For tomographic procedures, the source and the imaging device are interconnected by shielded drive system components to effect coordinated movement of the source and the device. For conventional radiography, the drive components are disconnected to permit independent movement of the source and the imaging device. The drive components are disconnected for conventional radiography by lowering the X-ray source and by operating a latch located near the imaging device. The drive components are connected for tomography by raising the X-ray source and by operating the latch. Other improvements such as the use of rotary encoders to provide a digital readout of the location of a tomographic examination plane and to control the operation of the source during tomographic procedures are described.

Abstract: A closed loop feedback system for controlling the current output of an x-ray tube. The system has circuitry for improving the transient response and stability of the x-ray tube current over a substantial nonlinear portion of the tube current production characteristic.The system includes a reference generator for applying adjustable step function reference signals representing desired tube currents. The system also includes means for instantaneous sensing of actual tube current. An error detector compares the value of actual and reference tube current and produces an error signal as a function of their difference. The system feedback loop includes amplification circuitry for controlling x-ray tube filament DC voltage to regulate tube current as a function of the error signal value.The system also includes compensation circuitry, between the reference generator and the amplification circuitry, to vary the loop gain of the feedback control system as a function of the reference magnitude.

Abstract: An improved semiconductor gamma camera is disclosed. The gamma camera includes a p-i-n semiconductor diode which detects the presence and energy of gamma radiation from a source. Typically the source is radioactive material in a patient organ which is detected and then interpreted by a doctor while diagnosing the condition of that organ. The detector includes an improved electrical connection technique to allow the p-i-n diode to be connected to electronic circuitry necessary to provide spatial and energy information. In the improved camera first a passivation layer is deposited on both faces of the p-i-n diode and then a resistive layer is applied to form a reliable easily reproduced electrical contact to the junction. These two layers in combination prevent foreign matter from contacting the semiconductor material comprising the detector while providing interconnection to the electronic circuitry.

Abstract: An apparatus for mounting a scintillation crystal in a detector assembly of a gamma imaging device. The mounting apparatus effectively isolates forces applied by a spring biased array of phototubes from a frangible scintillation crystal. The crystal is separately biased to the light pipe using only the minimum force needed to insure good optical coupling.

Abstract: An inclinometer (I) for attachment to a radiographic film cassette (C) for indicating on radiographic film in the cassette the angular orientation of the film during exposure. A cylindrical body (10) defines therein an array of cylindrical passages (12) having axes each orthogonal to the body cylinder axis. Each passage axis has a rotational orientation about the body axis which differs by approximately 10 degrees from that of its respective neighbors. A radiopaque spherical indicator element (14) is disposed within each respective column for gravity responsive movement as a function of angular orientation of the body structure. Clamping means (20, 22) holds the body structure superimposed over a portion of radiographic film to be exposed. The relative positions of the indicator elements within their respective passages appears on the exposed film, indicating the angular disposition of the film during exposure.

Abstract: An improved computer assisted tomographic scanner is disclosed. The scanner includes a source of X-radiation and an array of detectors for determining X-ray intensity once that radiation has passed through a patient. The source emits a spread of radiation which is filtered to comprise a spread of two distinct energy ranges before the radiation reaches the patient. This filtering produces multiple intensity readings for a given X-ray path: thereby allowing imaging electronics within the scanner to reduce chromatic artifacts and provide electron density and atomic number mappings to the diagnostician.

Abstract: A frequency program synthesizing apparatus and method is disclosed for controlling delay circuitry in ultrasonic imaging systems. Each frequency program synthesizer includes an adjustable frequency source for producing the clocking signals and a multichannel memory having a plurality of address channels each allocated for digitally storing a signal representing the frequency corresponding to one of said frequency program steps and circuitry for applying the stored signals in a sequence to cause the adjustable frequency generator to produce the frequency program. Each program synthesizer also includes updating circuitry for adjusting the values of the stored digital frequency representations to compensate for undesirable differences between the frequency of the generated program and a set of predetermined program frequency steps.

Abstract: A fluid mixing system and method is disclosed for automatically mixing precise concentrations of photographic processing chemistry to be used in an X-ray film processor. The system produces a fresh batch of mixed solution whenever a previous batch has been reduced to a predetermined minimum volume. A pair of substantially identically constructed mixing units are provided to produce both developer and fixer solutions for film processing. Each unit has: a chemical supply structure for supplying chemicals from containerized supplied; a storage and mixing tank structure which underlies the chemical supply structure and defines a reservoir for mixing the chemistry with water; a water input valve for selectively introducing water under pressure into the tank structure; control apparatus for conditionally controlling operation of the water valve; and a chemical release assembly which is coupled to and actuated by the water valve.

Abstract: A system for the automated analysis of large numbers of liquid samples, in which a multiplicity of sample tubes are loaded in racks into a cassette and the loaded cassette is transferred from station to station, with operations of sample insertion, dilution, reagent addition and withdrawal for filtering being performed at successive stations. At each station there is a separate processing module adapted to receive the cassette, each module including the apparatus necessary for performing one of the abovementioned operations on each individual sample tube when it is located at a particular operational location in the cassette. Each module also has members for shifting the racks in the cassette in such manner that all tubes pass through the operational location in turn while strictly maintaining the same order of sequence throughout the operations.