Abstract: The invention is directed to improvement in diagnostic medical ultrasound contrast agent imaging. Subharmonic and harmonic imaging are combined by generating a subharmonic frequency intensity value, generating a harmonic frequency intensity value, and generating display indicia as a function of both the subharmonic and harmonic intensity values. A first embodiment of the invention is directed to using predominantly harmonic information in one mode and predominantly subharmonic information in a second mode. A second embodiment of the invention is directed to combining harmonic and subharmonic information in the same mode.

Abstract: An ultrasonic imaging system that reduces image flashes by selectively replacing imaging parameters with corresponding imaging parameters from prior time sequences. Imaging parameters include filtered energy, unfiltered energy, variance, acceleration, velocity, and detected echo magnitude. Imaging parameters in several consecutive time sequences can be replaced with the same prior imaging parameter value until the flash is no longer detected. Spatial averaging can be used to improve detection and suppression of image flashes.

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: A method and apparatus for quantifying and displaying ultrasound signals in an ultrasonic system are provided. A first signal value for each of at least one spatial location in a region of interest is acquired at a first time, and the signal values are summed to obtain a first surface integral value. A second signal value for each of said at least one spatial location in said region of interest is acquired at a second time, and the second signal values are summed to obtain a second surface integral value. The first surface integral value is summed with the second surface integral value to obtain a time based integral. The time based integral is displayed. Other quantities based on any of various ultrasound parameters, such as Doppler energy, Doppler velocity and B-mode intensity, are calculated and displayed as quantities or as waveforms as a function of time. Furthermore, various comparisons of quantities and waveforms are provided. Image plane data or other ultrasound data are used in the calculations.

Abstract: A method and apparatus for quantifying and displaying ultrasound signals in an ultrasonic system are provided. A first signal value for each of at least one spatial location in a region of interest is acquired at a first time, and the signal values are summed to obtain a first surface integral value. A second signal value for each of said at least one spatial location in said region of interest is acquired at a second time, and the second signal values are summed to obtain a second surface integral value. The first surface integral value is summed with the second surface integral value to obtain a time based integral. The time based integral is displayed. Other quantities based on any of various ultrasound parameters, such as Doppler energy, Doppler velocity and B-mode intensity, are calculated and displayed as quantities or as waveforms as a function of time. Furthermore, various comparisons of quantities and waveforms are provided. Image plane data or other ultrasound data are used in the calculations.

Abstract: A method and system for obtaining ultrasound data with a sparse array of transducer elements is provided. About one wavelength of a highest operating frequency separates the center of each transducer element from any adjacent transducer element. While this spacing may generate grating lobes, the beamformer of the ultrasound system is configured to filter and isolate information at a harmonic of a fundamental transmit frequency. The resultant two-way beam pattern is less effected by the grating lobes. The image generated as a function of the harmonic information has few artifacts created as a function of the sparse spacing of the transducer elements. Given a set number of beamformer transmit channels, the sparse spacing may allow for a larger aperture width with few artifacts as a result of sparse element spacing. The larger aperture width generates a narrower beam in the azimuthal dimension of a one-dimensional transducer. By generating a narrower beam, better azimuthal resolution may be obtained.

Abstract: A region of interest in the body is imaged using at least two different trigger intervals between images. Imaging automatically switches from one trigger interval to another in response to a user command, such as depressing a button. This automation avoids cumbersome manual changes of the trigger intervals. Perfusion is measured in a shorter time in this way, reducing the effects of breathing and transducer movement. Variation of the trigger intervals allows for a convenient determination of perfusion. For example, the trigger intervals are varied from one heart cycle to two heart cycles and then to other integer numbers of heart cycles.

Abstract: A method and system for detecting energy using pulse inversion and Doppler processing are provided. Pulse inversion may be used to image the harmonic response of tissue alone or with contrast agents. Lowpass or bandpass clutter filters suppress the harmonic and/or fundamental response of tissue clutter to provide improvements in imaging, such as for imaging small vessels. Elimination of tissue clutter from both the fundamental components and second harmonic components in the Doppler domain increases the specificity of contrast agent and/or tissue.

Abstract: A method and system for determining the location of a region of interest throughout a sequence of images is provided. The system, in response to user input or automatically, identifies a region of interest associated with anatomy represented in an image. The data associated with the region of interest is compared with data for other or subsequent images. A maximum degree of correlation between the data associated with the region of interest and data for the subsequent image is determined. A translation and/or rotation associated with the maximum correlation determines the position of a region of interest designator in the subsequent image. The process may be repeated for a plurality of images. The same process may be used to determine the position of the designator in previous images.

Abstract: A method and apparatus for quantifying and displaying ultrasound signals in an ultrasonic system are provided. A first signal value for each of at least one spatial location in a region of interest is acquired at a first time, and the signal values are summed to obtain a first surface integral value. A second signal value for each of said at least one spatial location in said region of interest is acquired at a second time, and the second signal values are summed to obtain a second surface integral value. The first surface integral value is summed with the second surface integral value to obtain a time based integral. The time based integral is displayed. Other quantities based on any of various ultrasound parameters, such as Doppler energy, Doppler velocity and B-mode intensity, are calculated and displayed as quantities or as waveforms as a function of time. Furthermore, various comparisons of quantities and waveforms are provided. Image plane data or other ultrasound data are used in the calculations.

Abstract: A framework removal tool method is provided. The tool comprises a first side of a stake contact element including first and second notches with first and second dimensions, respectively. A lever arm connects to the stake contact element. One of the first or second notches is selected based on a dimension of a stake. The selected notch is placed adjacent the stake. The lever arm is rotated to remove the stake. In another embodiment, a second tool for removing stakes is provided. The tool includes a bar with a nail removal notch on a first end, and a stake contact element connected to the bar near the first end. The stake contact element includes at least a first stake notch on a first side. A rounded extension rigidly connects to the bar near the first end.

Abstract: A means of ballasting for high intensity discharge (HID) lamps, wherein the necessary lamp striking voltage, warm-up current and steady state running current may all be controlled using only two power switching transistors 9,10 operating in two discrete modes. A further feature provides a means of lamp power control over a range of lamp voltages such that the lamp power input remains substantially constant throughout the ageing of the lamp 19. The use of this means of ballasting HID lamps can offer major cost benefits, lower circuit complexity, longer lamp life and colour maintenance and increased flexibility of the wiring installation and lamp position relative to the ballasting and striking means.

Abstract: A method and system for Doppler processing of information at two or more different frequency bands for improved accuracy is provided. Signals from two or more unique frequency bands are processed separately to detect motion. Using signals at different frequency bands allows for more effective use of unused bandwidth to increase information content and improve estimation accuracy. One of or more of the two or more receive frequency bands may be within the transmitted fundamental frequency band or within harmonic frequency bands of the transmitted fundamental frequency band. The increased information content generated by using two separate narrow receive frequency bands is used to improve many aspects of motion detection. The resulting Doppler values of each parameter, such as velocity, energy, and variance parameters, are averaged or otherwise combined. One of the average, the Doppler values at each frequency band and a null value are selected for further processing and display.

Abstract: A method and system for imaging contrast agent within human or animal tissue, organs and/or blood is provided. Contrast agents, such as perfluorocarbon gas-filled albumin microbubbles which exhibit momentary contrast enhancement when exposed to high intensity ultrasound are injected into a patient. Periodic images are generated to avoid reduction in the contrast provided by the contrast agents due to ultrasound destruction. Between the periodic images, an M-mode image is substantially continuously updated to allow the user to better locate and maintain imaging of a region of interest, determine dynamic movement within the region of interest, access attenuation, determine an appropriate trigger point, and view perfusion of the contrast agent between the periodic images while minimizing destruction of contrast agent. In one embodiment, an ultrasound system alternates between triggered firings of a two-dimensional B-mode image and substantially continuous updating of an M-mode image.

Abstract: A method and system for obtaining ultrasound data is provided. Two or more transducer elements are shorted or connected to the same transmit or receive channel for a single transmit or receive event. The affect of any grating lobes generated from shorting the transducer elements are minimized by receiving acoustic energy and then obtaining ultrasound data at a harmonic of a fundamental transmit frequency. No contrast agent is added during imaging. A multiplexer with a limited number of switches is used to short pairs of transducer elements together. Alternatively, a multiplexer with a limited number of switches is used to transmit or receive from spaced apertures, such as by connecting a channel to every second transducer element.

Abstract: An AC voltage reduction system and method providing highly efficient reduction of utility voltage with minimal electromagnetic interference is provided. The systems and methods may also be used to improve overall facility power factor. The AC voltage provided to a load, such as a group of lighting ballasts connected on a single circuit, is reduced by a controllable switch coupled in parallel with a capacitor between the AC source and the load. The switch is controlled to turn-on when the voltage across the capacitor is very close to zero and turn-off prior to the next zero-crossing of the line current. The turn-off time is selected in an open loop configuration independently of a measured characteristic of load voltage or watts. In order to provide proper operation of gas discharge lighting, the switch is initially turned off just in advance of the AC source current zero-crossing.

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: A medical diagnostic ultrasound method and system for simultaneous phase correction of signal components at two frequency bands is provided. Simultaneous phase correction is performed, in part, during transmission of ultrasound waveforms and, in part, during reception of returning echoes. The phase between any two transmitted beams is adjusted by a first phase value. The phase between any two received beams is adjusted by a second phase value. Selection of the first and second phase values allows for simultaneous correction of signal components at two different frequency bands. For example, fundamental and second harmonic frequency bands are corrected for coherent imaging or processing. The phase corrections may account for different transmit and receive processes, such as fixed focus transmission and dynamic receive focusing.