General Electric Company

Litton Industrial Products, Inc.

John E Mahony

Robert W Cribbs

Steven Charles Miller

Larry Y Mo

Theodore Lauer Rhyne

Christopher J Gilling

Kok-Hwee Ng

A method using a progressive sampling rate technique to maintain the sampling rate at the Nyquist frequency of the I/Q data through a tunable equalization bandpass filter in the front end of the imager and then increasing the sampling rate via axial interpolation to prevent aliasing during the nonlinear detection process. If an envelope detector is used, the bandwidth of the detector output should be approximately double that of the I/Q data. In this case, the sampling rate is doubled (or more) by axial interpolation before envelope detection. A 2-point linear interpolator can be used. Depending on the application, this axial interpolator can be turned on or off automatically by the system. After detection, the signal can be low-pass filtered to restrict the speckle bandwidth prior to log compression.

Method and apparatus for preventing axial spatial aliasing in ultrasound

A color flow processor for color flow imaging of the velocity of scatterers flowing past slowly moving tissue. The processor has inputs for receiving basebanded signals derived from ultrasound reflected by the scatterers and by the slowly moving tissue; a wall estimator for processing the basebanded signals to output a wall frequency signal representing an estimated means Doppler frequency produced by the slowly moving tissue and a wall velocity signal representing an estimated velocity of the slowly moving tissue; a complex mixer for mixing the basebanded signal using the wall frequency signal so that the wall component is at DC and then outputting the mixed basebanded signals; and a flow estimator for processing the mixed basebanded signals and the wall velocity signal in an adaptive mode to output a flow velocity signal representing an estimated flow velocity of the scatterers which compensates for movement of the slowly moving tissue.

Color flow processor having adaptive wall filter

Noise is reduced in the television display of an A trace in an ultrasonic scanner system by integrating digital data representing the magnitude of video signals corresponding to the echos of ultrasonic pulses. The digital integration is accomplished on a point by point basis by summing digital data with stored digital data from previous video signals. Preferably, a capture memory is utilized with a digital summer for integrating the data while another memory periodically receives the integrated data and functions to refresh the television display. In another embodiment, two memories can alternate in capturing the integrated data and in refreshing the display.

Method and means for reducing noise in television display system

In a raster scan display in which electron beam energization during raster line scan is controlled by comparing a raster value to stored magnitude digital data as a raster line is scanned, a control signal for energizing the electron beam includes a lower bandwidth video signal whereby energization of the electron beam can be anticipated. A comparator of the raster line value to stored magnitude digital data generates a pulse which is applied to three serially connected latches. Logic circuitry connected to the latches generates pulses which are applied to digital to analog converter circuitry which generates the video control signal.

Method and means for controlling electron beam in a raster scan monitor

Distortion is minimized in displaying a waveform on a television display where the wave is identified by sequential magnitude points. The midpoint between consecutive magnitude points is determined, and raster line points in the television display are illuminated along the vertical axis from each magnitude point to the adjacent midpoint thereby minimizing the box-like image of complex waves.

Method and means for minimizing distortion in television display

Time gain compensation is provided in an ultrasonic scanner by storing a digital code in memory representing the desired signal gain for intervals of time during the reflected wave. Gain compensation due to transducer parameter can be provided in digital form in a separate memory, and the outputs of the two memories are combined and applied to a digital to analog converter. The resulting analog control signal is preferably filtered and then applied as a control signal to a gain control amplifier.

Method and means for generating time gain compensation control signal

A low drift sample and hold circuit is disclosed comprising a transconductance input buffer coupled at its output to a plurality of CMOS inverters through a respective plurality of CMOS switches. The appropriate switches are momentarily addressed by a micro-processor while applying a respective input value to the buffer. The buffer is de-activated prior to the opening of the switch to prevent errors between the sampled and held values.

Sample and hold circuit

A computerized ultrasound scanner is disclosed having operator-actuable apparatus for selectively choosing one of a plurality of video processing techniques utilized to convert information from ultrasonic pulse reflections into a video displayed image of the interior region of an examined body.

Computerized ultrasonic scanner with technique-select

A method and circuitry are disclosed for displaying the A-Trace of ultrasonic reflections on a video screen. The disclosed system provides means for writing pulse reflection data into memory, and means for selectively accessing the memory to place the data on the screen in graphical form. The data is stored and accessed in a format which is compatible with the scan pattern associated with the video display.

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Sacramento, CA, United States of America

John E Mahony