Abstract: A method and apparatus are provided for imaging an object using a transducer array for transmitting one or more beams that are steered and/or translated to transmit scan lines for multiple excitation events so as to scan a field of view of the object, for sensing received signals reflected from the object after each excitation event on one or more receive beams on receive scan lines, and for transducing those sensed received signals into corresponding electrical signals.

Abstract: A method of imaging to aid tissue viability determinations is provided. Tissue motion is detected for at least region of tissue. Perfusion is estimated as a function of intensity data and time for the region of tissue. An image responsive to the detected tissue motion and the estimated perfusion is displayed. A combination of tissue motion imaging and perfusion estimation provides an assessment of tissue viability. If tissue exhibits perfusion and motion, then the tissue is likely normal. Any other perfusion and motion characteristic combination indicates abnormal tissue viability.

Abstract: An ultrasonic imaging system includes an ultrasonic transducer having an image data array and a tracking array at each end of the image data array. The tracking arrays are oriented transversely to the image data array. Images from the image data array are used to reconstruct a three-dimensional representation of the target. The relative movement between respective frames of the image data is automatically estimated by a motion estimator, based on frames of data from the tracking arrays. As the transducer is rotated about the azimuthal axis of the image data array, features of the target remain within the image planes of the tracking arrays. Movements of these features in the image planes of the tracking arrays are used to estimate motion as required for the three-dimensional reconstruction. Similar techniques estimate motion within the plane of an image to create an extended field of view.

Abstract: A method for imaging a target includes the steps of transmitting ultrasonic energy at a fundamental frequency and receiving reflected ultrasonic energy at a harmonic of the fundamental frequency. The transmitted ultrasonic energy is transmitted with a transducer array, and a central transmit waveform associated with a central one of the transducer elements comprises a lower frequency component and a higher frequency component that occur at different times.

Abstract: A method for imaging a target includes the steps of transmitting ultrasonic energy at a fundamental frequency and receiving reflected ultrasonic energy at a harmonic of the fundamental frequency. The ultrasonic energy is transmitted in power bursts, each having a respective envelope shape, wherein the envelope shapes rise gradually to a respective maximum value and fall gradually from the respective maximum value. Ultrasonic energy in the transmit beam is focused in an elongated high power region, as for example by means of a line focus.

Abstract: An ultrasonic imaging system generates a corrected Doppler energy signal as a function of both Doppler energy and Doppler velocity to correct for loss of sensitivity associated with the gradual roll off response characteristic of many clutter filters. Additionally, the corrected Doppler energy signal is generated as a function of Doppler variance to prevent enhancement of noisy samples.

Abstract: In an ultrasound system and method, a transducer connects to an estimator for obtaining first and second blood flow parameters associated with first and second scan line directions, respectively, in a first scan plane. One beam substantially covering a cross-sectional area of a tubular structure (uniform insonification) or a plurality of beams may be used. A first area associated with the cross-section of the tubular structure is also estimated from the blood flow parameters. The process is repeated for a plurality of scan planes. A processor determines the cross-sectional area of the tubular structure perpendicular to its axis (a second area), the average velocity of flow parallel to the axis, and the volume flow as a function of the first area and the first and second blood flow parameters of all the scan planes. For real-time volume flow, the orientation of the tubular structure is determined using the second area and the first and second blood flow parameters.

Abstract: An ultrasound system and method are presented for facilitating a reproducible ultrasound imaging environment by reducing the variability in ultrasound parameters as a source of discrepancy when performing serial studies. In this way, an operator can rigorously compare ultrasound images from a single patient and can ensure that a plurality of patients are imaged in the same way. Additionally, an imaging environment can be duplicated on a plurality of ultrasound systems. This is especially helpful in ensuring that several machines are configured in the same way and in tracking down unexpected behavior (e.g., hardware or software bugs or anomalies).

Abstract: An electronic device placed in series with the probe ground-to-chassis connection. The device comprises a current-detecting element such as a resistor or RC network and may employ frequency-discriminating circuitry to limit only ground current signals below a certain frequency. The detector element triggers either a current limiter or a latching switch to prevent currents exceeding about 20 .mu.A rms from flowing between the probe and the patient. This is achieved by limiting such currents dynamically or by latching the transducer-probe-ground/system-chassis connection in an "open" state. In normal operation, the limiting/latching function is inactive, i.e. it is transparent to the system and the device shunts noise signals to the system chassis to prevent image degradation. The resistance of the device in normal operation may be in the range of about 0.1 to 10 ohms for effective noise reduction (shielding) at operating frequencies at and above 100 kHz.

Abstract: A digital transmit beamformer system with multiple beam transmit capability has a plurality of multi-channel transmitters, each channel with a source of sampled, complex-valued initial waveform information representative of the ultimate desired waveform to be applied to one or more corresponding transducer elements for each beam. Each multi-channel transmitter applies beamformation delays and apodization to each channel's respective initial waveform information digitally, digitally modulates the information by a carrier frequency, and interpolates the information to the DAC sample rate for conversion to an analog signal and application to the associated transducer element(s). The beamformer transmitters can be programmed per channel and per beam with carrier frequency, delay, apodization and calibration values. For pulsed wave operation, pulse waveform parameters can be specified to the beamformer transmitters on a per firing basis, without degrading the scan frame rate to non-useful diagnostic levels.

Abstract: There is provided a transducer array with a plurality of piezoelectric elements having a minimum and maximum thickness. In one embodiment, the maximum thickness is less than or equal to 140 percent of the minimum thickness. In an alternate embodiment, the maximum thickness is greater than 140 percent of the minimum thickness and the transducer array is capable of simulating the excitation of a wider aperture two-dimensional transducer array. One or more matching layers may be used to further increase bandwidth performance. In addition, a two crystal transducer element as well as a composite transducer structure may be formed using the principles of this invention.

Abstract: A transducer array and method for medical imaging which produces an ultrasound beam upon excitation, the transducer array including a plurality of transducer elements, each of said transducer elements having a first surface facing a region of examination when the transducer is in use and a second surface opposite of the first surface wherein the second surface faces away from the region of examination when the transducer is in use, said second surface is concave in an elevation direction, and a focusing lens disposed on the first surface of each element.

Abstract: An ultrasonic imaging system includes a receive beamformer that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path includes both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality.

Abstract: An apparatus and method for processing ultrasound data is provided. The apparatus includes an interface operatively connected to a memory, a programmable single instruction multiple data processor (or two symmetric processors), a source of acoustic data (such as a data bus) and a system bus. The memory stores data from the processor, ultrasound data from the source, and data from the system bus. The processor has direct access to the memory. Alternatively, the system bus has direct access to the memory. The interface device translates logically addressed ultrasound data to physically addressed ultrasound data for storage in a memory. The translation is the same for data from both the processor and the source for at least a portion of a range of addresses. The memory stores both ultrasound data and various of: beamformer control data, instruction data for the processor, display text plane information, control plane data, and a table of memory addresses. One peripheral connects to the ultrasound apparatus.

Abstract: An ultrasonic transducer array for harmonic imaging including an ultrasonic transducer array having a plurality of transducer elements, each of said transducer elements having a first surface and a second surface opposite of said first surface, said second surface being non-planar in an elevation direction and said second surface facing away from a region of examination when the transducer is in use. Transmit circuitry is coupled to the transducer array and is operative to cause the transducer array to emit a signal having a bandwidth controlled such that substantially no harmonic energy is transmitted. Receive circuitry is coupled to the transducer array and selectively responsive to harmonic echo information.

Abstract: A patient is first injected with a contrast agent. A complete scan along a plurality of scan lines is then performed, resulting in the destruction of some contrast agent. While some of the contrast agent is destroyed, non-scanned portions of the target, and possibly the scan region, still include at least some contrast agent. A second scan is then sequentially performed sufficiently close in time to the first scan such that reflections from the anatomy remain unchanged. The second frame of data from the second scan will differ from the first frame of data from the first scan by only contrast agent effects. The second frame of data is subtracted from the first frame of data. The resulting data is used to image the contrast agent. By varying the time between each pair of scans, differences in the speed of the contrast agent motion within the body may be assessed. The collateral damage of contrast agents from ultrasound acoustic energy is minimized while the degradation due to various changes is also minimized.

Abstract: In an ultrasound system and method, a transducer connects to an estimator for obtaining first and second blood flow parameters associated with first and second scan line directions, respectively, in a first scan plane. One beam substantially covering a cross-sectional area of a tubular structure (uniform insonification) or a plurality of beams may be used. A first area associated with the cross-section of the tubular structure is also estimated from the blood flow parameters. The process is repeated for a plurality of scan planes. A processor determines the cross-sectional area of the tubular structure perpendicular to its axis (a second area), the average velocity of flow parallel to the axis, and the volume flow as a function of the first area and the first and second blood flow parameters of all the scan planes. For real-time volume flow, the orientation of the tubular structure is determined using the second area and the first and second blood flow parameters.

Abstract: An EMI filter and method of manufacturing thereof is described. The filter includes two or more power conductors and a ground conductor. The power conductors and the ground conductor are separately wound onto a core to form a common-mode choke. The filter may be located in an equipment chassis. Capacitors may be coupled to the choke to improve filter performance. The core may comprise at least two magnetic beads. The core material and number of turns of the conductors may be chose to control the frequency range of common-mode noise rejection. The frequency range may be that in which adequate common-mode noise rejection is achieved for a diagnostic ultrasound machine, e.g., approximately 0 to 20 MHz.

Abstract: A method and system for an ultrasound beamformer with an integrated circuit is provided. Both digital transmit and digital receive beam formation are processed on a single integrated circuit receiver is provided. The transmit beamformer includes transmit logic and a digital to analog converter. The receive beamformer includes receive logic and an analog to digital converter. In one preferred embodiment, the integrated circuit includes a generic gate array with a designed logic metal layer for implementing the transmit and receive logic. The converters allow analog inputs and outputs, reducing the pin count. Reduction in pin count may permit cost reductions as process geometries become smaller. By placing both logic functions on one IC, fewer ICs are required in each system and the volume for that particular IC may increase, reducing the cost.

Abstract: An ultrasonic imaging system generates Doppler and B-mode image signals, and then uses a modulated, non-linear mapping function to combine the Doppler and B-mode image signals into an output signal. In another mode of operation the imaging system generates fundamental and harmonic frequency intensity values and maps these intensity values to display indicia, preferably with a modulated, non-linear mapping function.