Abstract: A system employs a tracker and a set of substantially non-shadowing point markers, arranged in a fixed pattern or set in a fluoroscope calibration fixture that is imaged in each shot. The fixture is preferably affixed to the image detector of the fluoroscope, and tracking elements secured with respect to the fixture and at least one of a tool and the patient, provide respective position data irrespective of movement. A marker detection module identifies markers imaged in each shot, and a processor applies the known marker positions to model the projection geometry, e.g., camera axis and focus, for the shot and, together with the tracked tool position, form a corrected tool navigation image. In one embodiment an inverting distortion correction converts the tracked or actual location of the tool and displays the tool on the fluoroscopic image to guide the surgeon in tool navigation.

Abstract: G.E. DOCKET NUMBER 15-DS-00536A system and method for measuring a position of an imaging element located within a scanhead of an imaging probe, such as transesophageal ultrasound probe, is provided. The imaging probe may be used in a medical imaging system and/or a three-dimensional imaging system. The probe includes an articulating portion having a scanhead. The scanhead includes an imaging element, such as a transducer, and a position sensor positioned within the scanhead. Preferably, the position sensor is connected to the imaging element via an axle. Therefore, the rotation of the position sensor is synchronized to the rotation of the imaging element. The location of the position sensor within the imaging element provides accurate measurement of the position of the imaging element. The position sensor preferably includes a code disk having apertures and a system of light emitters and detectors.

Abstract: A transesophageal ultrasound probe allowing for scan-plane rotation comprises an endoscope with a probe head connected to the distal end of the endoscope. A transducer is secured to the probe head. A transfer mechanism is connected to the transducer. A motor at the distal end of the endoscope is connected to the transfer mechanism. Finally, an electrical wire is connected to the motor. The transesophageal ultrasound probe uses a motor in the tip of the transesophageal ultrasound probe for scan-plane rotation.

Abstract: A brake for a medical table (20) includes a speed detector (40) for determining when the table speed is greater than a threshold value. If the table is moving at greater than the threshold value, the brake is prevented from engaging to prevent the patient from being jolted. When the brake is engaged, teeth (91-95) of a brake tooth member (90) mesh with a groove set assembly (70). The teeth have central planes (A). Each of the teeth has sidewalls that define planes (P1 and P2) which make acute angles with respect to the respective central planes. A position detector (110) warns an operator when the brake is not engaged. A linear bearing assembly (125) guides the brake into the engaged position. A pawl assembly (100) hold the brake in the engaged position until released.

Abstract: A magnetic resonant imaging apparatus having an operator console with input and output devices, a computer system for acquiring, processing and storing MRI images, and a system control device for generating and acquiring MRI image data. The magnetic resonant imaging apparatus comprises a table and a magnet assembly. An embodiment of the magnetic resonant imaging apparatus provides for the magnetic assembly to be positioned below the table. Another examplary embodiment of the magnetic resonant imaging apparatus provides for the magnetic assembly to be positioned at one end of the table and at the side of a table with the magnet assembly in a perpendicular aspect with respect to the table. The magnet assembly can be positioned with a partition member disposed between the table and the magnet assembly.

Abstract: An automatic exposure control for an x-ray system using a large area solid state x-ray detector (26) includes an exposure control (36, 34) arranged to generate data of interest within the data generated by the detector and to adjust the dosage of x-rays to a predetermined level in response to data of interest so that an x-ray image of a patient is generated using the predetermined level.

Abstract: A modular intervention bed for use with a medical tomographic imaging system having an associated patient transport device and an imaging device. The modular intervention bed comprises a trestle configured to engage a patient transport device, with the trestle having an intervention area. A patient couch movably mounted on the trestle, with the patient couch defining an opening corresponding to the intervention area. The couch comprises a plurality of patient mats with each mat connected to at least one other mat, a pair of rollers mounted on each mat in a spaced apart relationship with each roller proximate an outside edge of each mat. The modular intervention bed can be reconfigured by adding or removing a mat thereby moving the intervention area and opening to correspond with the portion of a patient under investigation during an intervention procedure guided by a medical tomographic imaging system.

Abstract: A method and apparatus for calibrating the resolution of a medical imaging system measures unadjusted performance of a digital image detector used in the medical imaging system. The method then determines a weighting coefficient for a spatial frequency band processed by the medical imaging system. The weighting coefficient is based on a desired performance of the digital image detector and the unadjusted performance of the digital image detector. The method stores the weighting coefficient for subsequent application to the spatial frequency band by the medical imaging system. Identical or distinct weighting coefficients may be used at multiple spatial resolution levels. A single weighting coefficient may applied to all pixels at a given spatial resolution, or numerous spatial resolution variation compensation coefficients may be used in different regions of each spatial resolution.

Abstract: A method and apparatus for correcting electronic offset and gain variations in solid state x-ray detectors includes dedicating rows at the end of an x-ray detector scan. The dedicated rows may be used to measure the “signal” induced by electronic offset and gain variations in solid state x-ray detectors. The first row may be used to measure the signal induced by electronic offset. The second row may be used to measure to signal induced by gain variations. Measurements of the induced signals taken from the dedicated rows may be used to eliminate structured artifacts from the x-ray image.

Abstract: An electronic detent apparatus and method for simulating a mechanical detent comprises a sensor connected to a microprocessor. A servo-motor is connected to the microprocessor and has a motor drive connected to a clutch. The clutch may engage a wheel disposed upon a rail or surface to effect the simulation of a mechanical detent through the microprocessor controlled servo-motor. The method for simulating a mechanical detent comprises the steps of moving an axis and monitoring the position and velocity of the axis. The position and velocity of the axis is then compared to a pre-specified position threshold value and a pre-specified velocity threshold value using a microprocessor disposed on the axis. A servo-motor is activated to accelerate the axis to a pre-specified position using a clutch controlled by the servo-motor when the position and velocity of the axis exceed the pre-specified position and velocity threshold values.

Abstract: A multiple row spiral grooved bearing assembly 26 for use in a rotating anode X ray tube device 10 has an intermediate race 32 having a spiral grooved inner 34 and outer 36 surface placed between an outer housing 28 and an inner bearing shaft 30. A layer of gallium 42, 44 is interposed between the spiral grooved inner surface 34 and the inner bearing shaft 30 and between the spiral grooved outer surface 36 and outer housing 28 to provide lubrication for the surfaces of the intermediate race 32. The intermediate race 32 reduces the relative velocity between moving parts, thereby reducing heat generation of the bearing assembly 26 for a given anode rotation speed. This enables higher target 14 velocities, and hence higher focal spot power, available to the x-ray tube device 10 as compared with traditional ball-type bearing designs.

Abstract: An apparatus and method are provided for sealing a light imaging array and scintillator of an imaging device which prevents light or moisture from entering the sealed cavity while controlling the lateral expansion of the epoxy material during construction. The seal is formed by dispensing a bead of epoxy around substantially the entire perimeter of the active imaging array and scintillator, leaving a slight gap therein. A cover plate is then placed over the scintillator and imaging array to protect against light or moisture entering the sealed cavity from the side of the substrate that is sealed. As the cover plate is attached, it compresses the epoxy. During compression, pressure builds within the sealed cavity. However, the pressure is allowed to escape through the gap in the epoxy bead. The pressure release lowers the outward force against the epoxy bead, which in turn limits the lateral expansion of the epoxy.

Abstract: An ultrasound scanning system (10) includes a plurality of range gates (71-74) responsive to ultrasound waves for generating a plurality of Doppler signal samples representing different depth increments within a subject (S) being studied. A logic unit (30) generates Doppler frequency signals and generates B-mode data. A display (60) generates a B-mode image and a Doppler image which may be superimposed on the B-mode image. The Doppler image (DI) is arranged to illustrate depth increments within the subject being studied versus Doppler velocity or frequency.

Abstract: A method and systems for obtaining 2D ultrasound images. The methods may comprise the steps of receiving ultrasonic information from a volumetric region of a body, volume scan converting the ultrasonic information from the volumetric region for processing a rendering box, and volume rendering the rendering box for projecting the rendering box onto a 2D slice by using volume rendering techniques. The systems may comprise an ultrasonic transducer for receiving ultrasonic information from a volumetric region of a body, a volume scan converter for processing a rendering box obtained from the volumetric region, and a volume rendering processor for projecting the rendering box onto a 2D slice by using volume rendering techniques for contrast enhancement.

Abstract: An ECG gated ultrasonic imaging compounding system and method for synthesizing a cineloop of a compound ultrasonic image such as a cardiac cycle is presented. In real-time operation, a series of image frames may be recorded at a frame rate over a cardiac cycle and stored in a cineloop memory. A second series of image frames are recorded over a second cardiac cycle. The image frames of the second cardiac cycle are frame-by-frame aligned in time and space with the corresponding image frames from the cineloop memory. The aligned frames are then combined to form a series of synthesized image frames which then replace the original image frames in the cineloop memory. Subsequent series of image frames are also combined with the synthesized image frames in the cineloop memory to form new synthesized image frames which then replace the old synthesized image frames in the image array, and so forth. The series of image frames may be triggered to begin at a cardiac event such as the R-event.

Abstract: In an X-ray imaging system having a detector and a tube disposed to project an X-ray beam field into the plane of the detector, visual indicators associated with the detector and the X-ray beam field, respectively, are provided for use in aligning the detector and beam field. A computational device is also provided for producing a signal representing offset, caused by X-ray beam angulation, between the geometric center of the beam field and the point at which the central axis of the projected X-ray beam intersects the detector plane. A display device, responsive to the produced signal, enables a system user to compensate for the offset when aligning the detector and beam field.

Abstract: A method and an apparatus for correcting refraction delay errors on curved probes for all ranges using cordic rotation. The angle &phgr; from the normal of an element to the focus is determined as a function of the angle of cordic rotation. Then a delay error correction is indexed using this angle &phgr;. The angular correction method is efficient in that it uses the inherent property of cordic rotation to calculate the only range-dependent variable required for the correction. Thus the additional hardware required to calculate the corrections is minimal, as the remaining correction variables are vector and range independent.

Abstract: A system and method for automatically positioning an image receptor based on the position of a manually positioned diagnostic source assembly in an X-ray imaging device is provided. In a preferred embodiment of the automated tracking system, an operator manually positions a diagnostic source assembly (DSA) over the area of a patient to be imaged. Sensors in the diagnostic source assembly transmit the position of the DSA to a system controller. The system controller then calculates an optimal position of an image receptor based on the position of the DSA. Once the optimal position is calculated, the system controller sends the optimal position to a motor drive, which positions the image receptor in the calculated optimal position. Position sensors in the image receptor then send positional data of the image receptor to the system controller, which verifies that the image receptor is in the calculated optimal position.

Abstract: A computerized tomography (CT) system having an apparatus and method for receiving high data rate communication is disclosed herein. The apparatus includes a controlled variable attenuator for attenuating an encoded digital data signal having a wide range of power levels, a digital envelope detector for de-encoding the encoded digital data signal, a noise filtering circuit for filtering out the residual undesirable encoded signal components, and a feedback loop for maintaining a desired signal level such that the encoded digital data signal is converted to its pre-encoded state suitable for processing to generate a CT image.

Abstract: A neural network prediction has been provided for predicting radiation exposure and/or Air-Kerma at a predefined arbitrary distance during an x-ray exposure; and for predicting radiation exposure and/or Air-Kerma area product for a radiographic x-ray exposure. The Air-Kerma levels are predicted directly from the x-ray exposure parameters. The method or model is provided to predict the radiation exposure or Air-Kerma for an arbitrary radiographic x-ray exposure by providing input variables to identify the spectral characteristics of the x-ray beam, providing a neural net which has been trained to calculate the exposure or Air-Kerma value, and by scaling the neural net output by the calibrated tube efficiency, and the actual current through the x-ray tube and the duration of the exposure. The prediction for exposure/Air-Kerma further applies the actual source-to-object distance, and the prediction for exposure/Air-Kerma area product further applies the actual imaged field area at a source-to-image distance.