Abstract: A BcD mode ultrasound imaging system including a Doppler processor which is configured to receive a Doppler signal having components that are corrupted by residue from color mode interleaving. The Doppler processor is configured to analyze the residue effect and compensate for the residue by filtering the received Doppler signal.

Abstract: A system and method for 3-D ultrasound image registration and 3-D motion estimation. A calibrated 3-D speckle function is first pre-determined for the transducer and the tissue to be scanned. A series of image frames are identified and grouped into 3-D big and small blocks. Blocks representing speckle are identified and then, a full width half maximum value sum-absolute-difference technique is used to obtain an out-of-plane motion estimation based on decorrelation characteristics throughout the volume. For in-plane motion estimation, cross-correlation characteristics between pairs of frames are compared and, using a minimum sum absolute value technique, an estimate of in-plane motion is obtained. Fuzzy logic techniques are then used to obtain more accurate estimates. Finally, the out-of-plane motion estimate is updated based on decorrelation characteristics of the speckle frames used for the in-plane determination using a full width half maximum value technique.

Abstract: Telemetry transmitting apparatus and a method are provided for reception and transmission of heart related electrical signals, such as electrocardiogram (EKG) and/or cardiac pacemaker signals, from a plurality of electrodes coupled to the body of a medical patient. A receiving facility of the apparatus receives a plurality of analog signals representing at least the EKG signals. An output signal representing the EKG signals is formed and transmitted, via a wireless coupling, to a telemetry receiver. An analog output port is provided on the telemetry transmitting apparatus. The analog output port is also coupled to the receiving facility. A plurality of output signals representing the EKG signals is provided to the analog output port of the telemetry transmitting apparatus. The analog output port may be coupled to buffers at the input terminals of the apparatus.

Abstract: A scan conversion method employing a graphical circle generator to calculate a circle having a predetermined radius in the raster domain. The resulting set of (x.sub.i y) points are assigned values from corresponding vector domain points using closest fit and interpolation methods. This process occurs for each value of r in the vector domain. Gaps in the pixel display resulting from quantization errors in the circle generation algorithm are accommodated via a gap interpolation method. In one embodiment, the Bresenham circle generator is employed.

Abstract: A method (280) and system (128) for selectively smoothing color flow images in a Doppler ultrasound system (100). A set of original digitized ultrasound signals is received for points (m, m-1, m-2) on a beamline (l-1), each point having associated with it a velocity signal (.phi..sub.j), a magnitude of autocorrelation signal (R.sub.i), and a power signal (P.sub.i). A point (X(1,1)) along a beamline is selected for processing. The set of digitized ultrasound signals is applied to a digital filter (152), and the digital filter computes a set of smoothed digitized ultrasound signals by computing an average velocity signal (.phi..sub.av), an average magnitude of autocorrelation signal (R.sub.av), and an average power signal (P.sub.av) of each point in the selected beamline and points in adjacent beamlines. For the selected point along the selected beamline, a selected velocity signal (.phi.(1,1)) is compared to a velocity threshold (V.sub.

Abstract: A subtraction MRA image is formed by subtracting a mask image formed from diastolic MR image data from an angiographic image formed from systolic MR image data. To permit acquisition of diastolic MR image data during regurgitation of arterial bloodflow, a saturation slab is established immediately adjacent the slice of interest and slightly overlapping it on its arterially downstream side.

Abstract: A fuzzy logic tissue/flow determination system receives echo amplitude, color amplitude, and velocity signals from an ultrasound imaging system. These values are applied to a set of fuzzy rules which quantify the amount by which the signal values vary from preset thresholds. The outputs of the fuzzy rules provide an indication of the plausibility that the echo signals represent a tissue or flow condition. The outputs from all the fuzzy rules are combined and de-fuzzified to produce a combined plausibility of the signals representing either a tissue or flow condition. The tissue/flow decision is made based on which plausibility is larger.

Abstract: A system interrogates a region with ultrasound and then generates a vector field of values representing the velocity sensed at a plurality of image element positions. Spatial changes in the velocity vector field are then determined and displayed to the user, preferably in real time. The spatial changes include divergence and/or the rotation (also known as "curl") of the velocity vector field. In order to enable display of the vector spatial change information, either magnitude values, projected values, or color-coded vector information may be computed and displayed. In order to reduce the effect of noise on differentiation operations, the system preferably smooths the velocity vector field before, after or at the same time as it determines divergence or rotation.

Abstract: A system and a method are provided for intensity modulated radiation treatment. A field on a patient (544) for irradiation is first defined. A beam of radiation (530) is then provided. This beam (530) passing through an opening defined by a beam-shielding device (540, 542). In the preferred embodiment, the beam shielding device is a single jaw (540) and a single collimator section (542). Single jaw (540) and single collimator section (542) are moved in one direction at different velocities to vary the opening for radiation beam (530).

Abstract: Ultrasound echo data is analyzed to compress jump noises by recalculating the value of data points whose magnitude exceeds the magnitude of a previous point by more than a predefined threshold. Any data that exceeds the threshold is recalculated according to the value of the slopes of the points that precede and after the point to be replaced. The value by which a data point is compressed is selected so that the DC component of the points after compression is nearly equal to the DC component of the points prior to the jump noise. In addition, to remove saturating clutter in a Doppler display or audio signal, the present invention determines if the power spectrum of the Doppler signals to be displayed exceeds a maximum power display and if so scales a portion of the I and Q signals that comprise the Doppler power spectrum by the ratio of the maximum power spectrum computed and the maximum that can be displayed.

Abstract: An ultrasound system produces composite color flow images of tissue samples. To reduce image flicker, the ultrasound system stores the data required to produce two sequential color flow images and computes a series of interpolated images that are displayed between the actual color flow images. A piece-wise interpolation function is used to create the interpolated images in order to prevent artificial smoothing of the image data. In addition, the ultrasound system quantizes the ultrasound data used to compute the interpolated images in order to reduce the amount of memory required to store the data for the sequential color flow images.

Abstract: A data compression method and apparatus for processing a stream of original data samples to produce a compressed data stream that comprises both compressed and not-compressed data samples. The technique includes a data compression means for applying a data compression technique to said original data samples so as to develop a sequence of compressed original samples and not-compressed original samples, and providing the sequence of samples in a data portion of a transmission packet. A compression indicator means is also provided for developing a sequence of bits indicating which of the samples in the compressed data stream are representative of one of the compressed original samples and not-compressed original samples, and providing the sequence of bits in a map portion of the transmission packet. The map portion of the transmission packet is used for rapid identification and decompression of the compressed data.

Abstract: An improved digital wall filter comprises an infinite impulse response (IIR) second order digital filter. The coefficients w(-1) and w(-2) are pre-initialized from a set of m samples of the input signal. The number of samples m is related to the ratio of a constant .gamma., selected between 0 and 1, and the feedback filter coefficients. To ensure maximum performance of the filter, the filter is periodically re-initialized before filtering a new set of input data. To produce a video line, the filtered data created from the input samples used to initialize the filter are averaged with data that was not used to initialize the filter.

Abstract: A system and method for identifying and processing individual patients among a set of patients includes storing position data representative of patient-unique arrangements of targets that are affixed to the patients for aligning a therapeutic radiation beam. Subsequent to the recording of the position data, a particular patient and/or the medical information of the particular patient can be identified by reimaging the targets or substitute targets on the particular patient to detect a correlation between the image data and the stored position data. The correlation may be used to register a patient, track the location of the patient within a multi-station facility, or facilitate treatment setup, such as beam-to-patient alignment, radiation configuration, and beam control.

Abstract: A method and apparatus for classifying an input as belonging to one of a plurality of predefined classes, comprises: (a) developing a plurality of feature values and forming a feature vector from the feature values which is representative of the input, (b) applying the feature vector to a knowledge-base comprising predictivity curves for each class of said plurality of classes, and developing a plurality of predictivity values for each feature, each predictivity value being indicative of a likelihood of the input belonging to a respective one of each of said classes based on the feature value; (c) combining the predictivity values developed for each of the features for each class to generate a total predictivity value for each class; and (d) generating a determination of class based upon the total predictivity values generated by the prior step.

Abstract: A method and apparatus is provided for converting the frame rate of digital video data from one frame rate to another frame rate without introducing motion artifacts into the converted video data stream. A high frame rate video stream is converted into a lower frame rate video stream by selecting whole frames from the high frame rate video stream and outputting the selected frames as the lower frame rate video stream. To insure that only whole frames are selected from the high frame rate video stream, the frame rate of the high frame rate video stream is locked to the frame rate of the lower frame rate video stream. A frame cycle is defined to be an integer number of frames in the higher frame rate stream. The higher and lower frame rates are locked by repeatedly selecting and outputting as the lower frame rate video stream, over a time period that is substantially equal to one frame cycle, an integer number of frames from each frame cycle of the higher frame rate.

Abstract: A cylindrical alkali halide single-crystal-type ingot having an axis generally coinciding with the ?001! crystallographic direction is compressed in a heated dual platen press. To produce an approximately rectangular compressed ingot that is devoid of cracks and fissures at and adjacent the periphery, the surface of the ingot is flatted. For crystals having a face-centered lattice (e.g. NaI), the flat is parallel to the (100) crystallographic plane. For crystals having a body-centered lattice (e.g. CsI), the flat is parallel to the (110) crystallographic plane. The flat is placed on the lower platen of the press to properly orient the crystallographic structure of the ingot with respect to the direction of compression.

Abstract: Ultrasound gray-scale image data and corresponding processed gray-scale image data are color-enhanced to generate an enhanced multi-color image. At one step, a color map look-up table is defined from the processed gray-scale image data to define a color palette of K colors, (e.g., K=4-16). Histogram analysis, nonlinear mapping or segmentation processing is used to map the gray-scale levels to the color palette. The processed gray-scale image data then is transposed into a transposed color image data set. Data interpolation then is performed in which each pixel of the original gray-scale image data is interpolated with a corresponding pixel among the transposed color image data set. Interpolation weighting is adjustable by the user to determine how much detail from the original gray scale image is preserved.

Abstract: A method and apparatus for displaying physiological signals acquired from a patient in a manner that allows for reliably associating with the physiological signals acquired from the patient user generated message information. The method comprises the steps of, receiving at a central station physiological signals acquired from a patient; and arranging a display portion of the central station to have at least one first display area dedicated for displaying said physiological signals, and at least one second display area, located adjacent said first display area, dedicated for displaying a user generated message related to the physiological signals displayed in said first area.

Abstract: An image registration based method and a corresponding apparatus are provided for creating composite, panoramic images, in which consecutive ultrasonic image frames are correlated in order to derive transducer motion information. The individual images can be divided into several smaller sub-image regions and a fast and robust image motion detection algorithm is used to measure the sub-image motion and then to determine an initial estimation of the local motion vectors. The initial estimation is combined with two measurement parameters by use of a fuzzy logic technique to derive a final estimation of the local motion vectors. The final local motion vectors are then used to estimate global image motion. Compound images are then diplayed based on the derived global image motion. The speed of motion of the transducer is also estimated and a "speedometer" is displayed to help the user move the transducer within efficient speed ranges.