Abstract: In accordance with the principles of the present invention, advantage is taken by the inventors of the fact that the speed of operation of the digital hardware in a digital beamformer can be reduced by providing, for example, multiple phases of the data signals and then processing the multi-phase data in N parallel summing paths. An interpolation-decimation filter receives the multi-phase data from the N parallel summing paths and provides at its output a signal having a reduced data rate (1/N). In accordance with this technique, the speed of operation of the individual digital circuits for forming the required beamforming delays is not increased as compared to conventional post-beamforming interpolation schemes, so that hereby the effective data rate is increased by a factor N and results in a decrease of the delay quantization error by a factor N. In accordance with the principles of the invention, the interpolation-decimation filter is incorporated into the beamformer at a most advantageous place.

Abstract: An interrogation region of a patient's body is scanned with an ultrasonic probe. At least one input data frame is generated representing the scanned interrogation region as a pattern of image elements, each with a corresponding input intensity value, that are stored in a memory. The input data frame is then displayed as a pattern of displayed intensity values, which the processor calculates as combination of a geometry-independent function of an ambient light input array and a geometry-dependent function of the input intensity values, in which the geometry-dependent function includes a coefficient term that multiplies the input intensity array and that itself is a function of the input intensity values. As part of the coefficient term is a filtered input data array, which results from noise-floor filtering, low-pass filtering, and surface normal vector averaging of the input intensity array.

Abstract: Two conjugate views of a patient are acquired during a SPECT nuclear medicine study. A common anatomical feature is identified in the views. Based on the differences in location of the common feature in the views, the center of rotation ("COR") of the detector during the study can be calculated after the study has been concluded. This COR can then be used during image reconstruction to determine the location at which each filtered view is backprojected. The resulting SPECT data is of higher quality because COR artifacts in the reconstructed image are reduced or eliminated.

Abstract: Power values of backscattered ultrasonic echoes from an interrogation region of a patient's body are stored in a 2-D envelope table. The region is thereby represented as a 2-D pattern of image elements. In a processing mode, these elements are grouped into processing windows. After row averaging of the power values for each window, a window attenuation coefficient is generated corresponding to a decay parameter of a non-linear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window. The coefficients are then used to scale the power values before scan conversion and display, and thus to compensate for local attenuation. The invention can also test for tissue heterogeneity by first defining convergence and non-convergence criteria. A rationalized gain control processor then iteratively estimates the window attenuation coefficients until either criterion is met.

Abstract: A method for operating a digital computer to suppress reverberation artifacts in an ultrasound image. The image includes an ordered array of pixels, each the pixel corresponding to the intensity of the echo generated by a corresponding voxel in an ultrasound energy field. The ordered array has axial and lateral directions defined therein, the axial direction corresponding to voxels on the same radial line from a transducer used to generate the ultrasound energy field. The method starts by dividing the image into a plurality of segmentation blocks thereby generating an ordered array of segmentation blocks. The columns of the segmentation block array are chosen such that all segmentation blocks in the same column correspond to the same axial direction in the ultrasound image. In the preferred embodiment of the present invention, at least one segmentation block is classified as having a strong edge.

Abstract: First and second scintillation camera detectors are provided and are mounted, respectively, to first and second yoke assemblies. The first yoke assembly is mounted to a ring gear which is rotatable within a vertical plane about a horizontal axis. The second yoke assembly is mounted to an annulus which is located within the ring gear and which is rotatable within the plane and about the axis. A rotating device is provided for rotating the ring gear in the plane and about the axis and a locking device is also provided for locking the first and second yoke assemblies together, whereby the first and second yoke assemblies rotate together when they are locked together and the first yoke assembly is being rotated by the rotating device. Advantageously, each detector is pivotally secured to its corresponding yoke assembly and each of the detectors is radially movable towards and away from the axis of the gantry. Further advantageously, the entire gantry is laterally moveable.

Abstract: An additional status display of a touch panel on a CRT will maximize the operator's eye contact with the CRT while retaining the ability to select from the panel even though it is removed from the CRT and possibly located in another plane.

Abstract: A vibratory energy (ultrasonic) imaging system of the type including a transducer array having a plurality of transducer elements for generating pulses of vibratory energy which are directed towards reflectors and which receive reflections of said vibratory energy and develop echo signals in response thereto. The array comprises a two-dimensional array of transducer elements arranged in a plurality of rows extending in a lateral dimension of the array and a plurality of columns extending in an elevation dimension of the array, at least one of a first type of said columns having elements of a first height in the elevation dimension and at least one of a second type of column having elements of a second height in the elevation dimension which is greater than the first height. In a preferred embodiment of the invention, the first height is an integral fraction of the second height.

Abstract: An automatic blood pressure monitor has a dual-speed control circuit which is used to control the speed of a DC motor that powers the inflation cuff. The control circuit limits the motor current, permitting operation from a limited power source (such as a battery). The control circuit also includes structure for electrically braking the motor; the motor is braked after a time delay which commences after motor power is cut off.

Abstract: When a PMT "views" a scintillation event in the scintillation crystal of a scintillation camera system, the PMT produces an output signal. Based on the output signal, the event can be localized to a circular locus of points ("PMT locus"). Further localization can be accomplished on the basis of straight lines which are unambigously determined by intersections between such PMT loci.

Abstract: A method for measuring the interframe movement of pixels in a second ultrasoud image frame with respect to the pixels in a first ultrasoud image frame. The movement information may be displayed to provide enhanced information about the underlying physiology or to provide a temporally compounded image having reduced noise. In the preferred embodiment of the present invention, the pixels in that actually change between frames are identified. The first frame is divided into blocks and an estimated velocity computed for each block having a sufficient number of pixels that actually moved between the first and second frames. After all of the velocity estimates have been computed, blocks having questionable velocity estimates are identified. Blocks for which the velocity estimate was questionable are then provided with a velocity estimate by interpolating the velocity vectors of the nearby blocks having valid velocity estimates.

Abstract: Time-of-flight calculations may be simplified by performing them on the fly at selected intervals and then interpolating the results to obtain a comprehensive set of values. The method and apparatus offer improved accuracy, speed, and hardware savings.

Abstract: An ultrasonic Doppler flow (i.e. blood) imaging and/or measuring system capable of adaptively suppressing stationary or slowly-moving non-flow (i.e. blood) signals having variable spectra from the recovered ultrasonic echoes. In accordance with the invention, the tissue signals are suppressed using a tissue rejection filter arrangement having an attenuation characteristic which is controlled based upon measured estimates of at least one spectral characteristic of the tissue signals to be removed, thereby maximizing the rejection of tissue movement signals and minimizing undesired attenuation of the blood flow signals. In accordance with an embodiment of the invention, data representative of the tissue signal movement, e.g., the spectral estimates of the tissue signals, are spatially averaged before being used to control the tissue rejection filter arrangement.

Abstract: The present invention relates to the use of diffusion weighted magnetic resonance imaging procedures for the diagnosis of conditions in which blood circulation or similar molecular displacements within biological tissues are measured. Pulse sequences are used in accordance with the invention which suppress the contribution of non-moving tissue or bulk motion.

Abstract: A photomultiplier uses an avalanche photodiode as a position-sensitive anode. The envelope of the photomultiplier has a flat input end. Electrically conductive regions mounted to the input end are configured to produce at the input end a potential distribution characteristic of a photomultiplier with a spherical-type input end as measured in a transverse plane immediately adjacent the spherical-type input end. A photocathode is located inside the photomultiplier and is electrically connected to the electrically conductivew regions. Advantageously, the envelope has flat sides and a square cross-section; in this instance, conductors are run along the sides to produce within the envelope a potential distribution characteristic of a photomultiplier which is cylindrical in cross-section, as measured at flat surfaces having the same shape as the envelope.

Abstract: MR angiography method and apparatus either moves the saturation slab or eliminates it during a predetermined portion of the patient's cardiac cycle. This permits an MR image of a slice of interest to contain information relating to arterial bloodflow without becoming degraded by regurgitated bloodflow and information relating to venous bloodflow.

Abstract: Ultrasound imaging apparatus for transmitting ultrasonic signals to a subject to be diagnosed and for reconstructing an ultrasonic diagnostic image from received ultrasonic echo signals, the ultrasound imaging apparatus including: (a) a plurality of transducer elements which are two-dimensionally oriented in an array having a lateral direction and an elevation direction, the transducer elements converting electrical driving signals supplied thereto into the ultrasonic transmitting signals and converting the ultrasonic echo signals into electrical echo signals; (b) apparatus for generating and supplying the electrical driving signals to the transducer elements; (c) apparatus for selectively combining the electrical driving signals and the electrical echo signals sent to or received from transducer elements in the elevation direction; and (d) apparatus for converting the selectively combined electrical echo signals into the ultrasound diagnostic image.

Abstract: A flexible multi-parameter conductor cable having coaxially symmetric elongated zones for signal carrying conductor placement therein, comprising an electrically conductive inner shield defining an electrically shielded inner longitudinal zone symmetrically disposed along and defining a center of said cable for containing at least one of a first type of signal carrying conductor, and an electrically conductive outer shield spaced a given distance symmetrically around said inner shield so as to define an electrically shielded outer longitudinal zone symmetrically disposed about said inner longitudinal zone for containing a plurality of at least a second type of signal carrying insulated conductor arranged in a single layer adjacent one another in said second longitudinal zone, said second type of conductor having an electrically conductive outer jacket in electrical contact with at least said outer shield.

Abstract: An ultrasonic Doppler flow (i.e. blood) imaging and/or measuring system capable of adaptively suppressing stationary or slowly-moving non-flow (i.e. tissue) signals having variable spectra from recovered ultrasonic echoes. In accordance with the invention, the tissue signals are suppressed using a tissue rejection filter having an attenuation characteristic which is controllably shaped based upon measured estimates of at least one spectral characteristic of the tissue signals to be removed, thereby maximizing the rejection of tissue movement signals and minimizing undesired attenuation of the blood flow signals. In accordance with one embodiment of the invention, the tissue rejection filter is embodied as a complex notch filter for filtering the baseband components of the recovered ultrasonic echoes, which filter has a variable notch shape and position as adaptively determined in response to changes in estimates of the spectral components of the tissue signal portion of the recovered echoes.

Abstract: A portable carrier module having a safety interconnect latch mechanism for securing the portable carrier module to a portable product. The portable carrier has a rail on one of its outer walls for engaging with a track on the portable product and for aligning the portable product to the portable carrier.