Abstract: An endo-luminal ultrasonic instrument has a motor with a rotatable drive shaft that oscillates back and forth. A flexible catheter sheath is coupled at one end to the motor to oscillate with the drive shaft. The sheath has an axis about which it oscillates and a diameter sized to fit inside a human blood vessel or other body lumen. An ultrasonic transducer is attached to the other end of the sheath to oscillate therewith. The transducer has an array of individually operable elements arranged parallel to the axis to form a rotatable beam perpendicular to the axis. Electronics near the motor operates the transducer elements. Wiring, passing through the catheter sheath connects electrically the transducer elements and the electronics. The electronics includes electronic beam focusing to enhance the axial resolution of the instrument.

Abstract: An ultrasound imager supports several ultrasonic transducers simultaneously. The imager polls the transducer connection ports to determine which transducers are connected to which port and displays attributes of each transducer in conjunction with a port identification on the screen. The user selects which transducer is to be driven using a trackball or cursor arrow which directs an indicator to point to the selected transducer.

Abstract: An ultrasonic blood flow measuring and imaging system comprises a transmit-receive transducer for transmitting ultrasonic waves toward and into the human body and for receiving reflected echo signals which are then processed for use in a Doppler blood flow imaging and display system. Multiple ultrasonic pulse beams are transmitted into the body at each of a number of angles in an area under diagnosis. For each angle, a plurality of reflected echo signals are received during successive predetermined time intervals. Each received echo signal has a stationary component reflected from essentially stationary tissue and a Doppler component reflected from areas where movement is sensed, such as blood flow. The reflected echo signals are processed in an MTI filter subtracting a stationary component from the received echo signals to thereby extract a Doppler signal representative of a Doppler component of the received echo signals.

Abstract: A foreground image is overlaid over a background image on a visual display. Specifically, an ultrasound signal is transmitted toward a target to be displayed in two dimensions. Echoes of the ultrasound signal are received from the target. Two-dimesional target data acquired from the received echoes are stored. The two-dimensional target data are presented on the visual display as a background image. Part of the target data are overlaid over the background image as a foreground image on the visual display. The size of the foreground image vis-a-vis the background image is changed by the user to permit better observation of an area of interest. Preferably, the size of the foreground image is changed without changing the area occupied by the foreground image on the visual display, which permits the invention to simulate the action of a magnifying glass. The user moves a cursor on the visual display to the center of an area of interest.

Abstract: A continuous wave driven ultrasonic transducer for determining doppler frequency shift in reflected ultrasonic pressure waves in which the transmitter and receiver sections are constructed of a composite core having a plurality of segments of piezoelectric material separated by acoustic suppression material. Also disclosed is a method of reducing acoustic and mechanical cross coupling between piezoelectric transmitter and receiver sections of an ultrasonic transducer by arranging segments of piezoelectric material in a lateral array, and separating the piezoelectric segments with ultrasonic acoustic suppression material to produce a composite transducer core of reduced acoustic and mechanical cross coupling.

Abstract: An ultrasonic blood flow measuring and imaging system comprises a transmit-receive transducer for transmitting ultrasonic pulses toward and into the human body and for receiving reflected echo signals which are then processed for use in a Doppler blood flow imaging and display system. Multiple ultrasonic pulses are transmitted into the body at each of a number for angles in an area under diagnosis. For each angle, a plurality of reflected echo signals are received during successive predetermined time intervals. Each received echo signal has a tissue motion Doppler component representative of reflection from moving tissue and a blood flow Doppler component representative of relfection from both moving tissue and flowing blood. The reflected echo signals are processed in a system which includes tissue velocity determining elements for estimating the velocity of the tissue motion, and tissue velocity canceller elements for removing a tissue velocity component from the received echo signals.

Abstract: The train of echoes received in an ultrasound imaging system having an array of ultrasound transducers is shaped and/or focused by first and second programmable beam focusing modules (16-24) in a dynamic receive focus mode. The elemental ultrasound echo signals from a plurality of channels connected to the elements of the transducer array are selectively attenuated and/or phased shifted according to the programs prescribed for the focus zones and combined by each module. The combined echo signals are further processed in conventional fashion (34-38). The modules operates alternately. One module is being programmed, while the other module is combining the elemental echo signals for processing. Each beam focusing module comprises a delay line (56-60) having a plurality of input taps and a cross point switch (52) selectively connecting the channels to the input taps. The module is programmed by selectively closing the individual cross points of the cross point switch. Beam shaping i.e.

Abstract: The train of echoes received in an ultrasound imaging system having an array of ultrasound transducers is shaped and/or focused by first and second programmable beam focusing modules in a dynamic receive focus mode. The elemental ultrasound echo signals from a plurality of channels connected to the elements of the transducer array are selectively attenuated and/or phased shifted according to the programs prescribed for the focus zones and combined by each module. The combined echo signals are further processed in conventional fashion. The modules operates alternately. One module is being programmed, while the other module is combining the elemental echo signals for processing. Each beam focusing module comprises a delay line having a plurality of input taps and a cross point switch selectively connecting the channels to the input taps. The module is programmed by selectively closing the individual cross points of the cross point switch. Beam shaping i.e.

Abstract: The train of echoes received in an ultrasound imaging system having an array of ultrasound transducers is shaped and/or focused by first and second programmable beam focusing modules (16-24) in a dynamic receive focus mode. The elemental ultrasound echo signals from a plurality of channels connected to the elements of the transducer array are selectively attenuated and/or phased shifted according to the programs prescribed for the focus zones and combined by each module. The combined echo signals are further processed in conventional fashion (34-38). The modules operates alternately. One module is being programmed, while the other module is combining the elemental echo signals for processing. Each beam focusing module comprises a delay line (56-60) having a plurality of input taps and a cross point switch (52) selectively connecting the channels to the input taps. The module is programmed by selectively closing the individual cross points of the cross point switch. Beam shaping i.e.

Abstract: A system for improving the flow estimation sensitivity of an ultrasonic Doppler flow imaging system includes an ultrasonic wave tranmitter and receiver for sequentially transmitting ultrasonic waves toward and into a living body and for receiving the reflected Doppler-shifted echo signals. A series of echo signals received from each of a number of points within the body are processed in a velocity estimator, using maximum entropy techniques, to produce an output signal representative of an estimated velocity of the flow at each of said points within the body. The processing means detects the series of echo signals for each point and calculates an average power spectrum based on the amplitude-versus-frequency distribution of the series of received echo signals. The power spectrum is calculated by fitting a first order polynomial to the series of echo signals, although higher order polynomials can be used.

Abstract: An ultrasonic transducer has two intersecting linear arrays defining a cross shaped transducer assembly having four arms and an intersecting area. A plurality of transverse grooves form transducer elements in the arms. Coaxial transducer elements are formed in the intersecting area. Each transducer element has its signal electrode on a common side of the transducer. One or both of the intersecting linear arrays may be curved along its longitudinal axis thus allowing the transducer to be mounted on cylindrical or spherical surfaces.

Abstract: A curved array ultrasonic transducer is manufactured by cutting a flat transducer plate, which is attached to a flexible support plate, into a plurality of segments, the segments being hingedly attached by the support plate. The support plate is bent to a radius and the conductive traces in a flexible circuit board are electrically connected to the transducer plate segments. The flexible circuit board, having a plurality of branches, is bent to a perpendicular position such that the traces in the plurality of branches become substantially aligned. The traces exiting the branches are then electrically connected to a pin and socket connector device.