Abstract: A multilayered transducer assembly and the method of fabricating a multilayered transducer assembly using commercially available sheets of piezoelectric material and depositing electrodes thereon. The top and bottom surfaces of each layer have a major and a minor electrode formed thereon. The layers are stacked together so that the minority electrode formed on one layer is in contact with a minority layer formed on an adjacent layer and a majority layer formed on a surface is in contact with a majority electrode formed on an adjacent layer.

Abstract: A system and method for tracking the position and orientation of a movable medical imaging device using a first and second sensor disposed on the device. The second sensor is of a different type than the first sensor and measures a P/O parameter different from that of the first sensor. The system and method also include techniques for recalibrating sensors using measurements from other sensors and improving the measurements made by some sensors using measurements from other sensors. The system and method also include measuring the position of a medical implement relative to a movable medical imaging device by providing a first and second subsystem on the medical implement and a third and fourth subsystem on the movable medical imaging device. The first subsystem has a sensor of a first type and the second subsystem has a sensor of a second type different from the sensor of the first type.

Abstract: A transmit beamformer includes multiple transducers, each responsive to a respective transmit waveform to produce a respective transducer waveform. A transmit waveform generator generates the transmit waveforms, and the transmit waveforms each include multiple frequency components. Progressively higher frequency components of the transmit waveforms are timed to cause corresponding progressively higher frequency components of the transducer waveforms to focus along a line at progressively shorter ranges. In this way, a frequency dependent line focus is achieved.

Abstract: Medical diagnostic ultrasonic imaging systems and methods image at a fractional harmonic such as f.sub.0 /2 or 3f.sub.0 /2, where f.sub.0 is the fundamental frequency of the associated transmit beam. In order to improve fractional harmonic imaging, the transmit beam includes a fractional harmonic seed component, which may also have a center frequency of f.sub.0 /2 or 3f.sub.0 /2. Multiple pulse imaging methods using transmit beams having such fractional harmonic seed components further enhance fractional harmonic imaging.

Abstract: A method and system for generating three-dimensional representations using opacity modulation are provided. The opacity level associated with each datum in a 3D volume data set is controlled as a function of at least one Doppler parameter, such as variance. Areas of high variance are assigned a higher level of opacity than areas of low variance. For a Doppler velocity image, velocities associated with high variance are displayed more opaquely than velocities associated with low variance, thereby emphasizing the more opaque regions. The more transparent velocities (i.e., those associated with low variance) still contribute to the image and are displayed. Other Doppler parameters may be used for the image, such as energy, tissue motion or variance. Furthermore, other Doppler parameters may be used to control the opacity, such as velocity, energy or tissue motion.

Abstract: An improved Doppler tissue imaging mode combines two Doppler image parameters developed as respective functions of receive signals acquired from a single firing event to generate a combined image parameter for display. In one example, the combined image parameter has a color hue that varies in a piecewise linear way with Doppler tissue velocity or Doppler tissue acceleration and a color value or intensity that varies linearly with Doppler tissue energy. Because the same firing events are used to develop both Doppler image parameters for a given region of tissue, high temporal and/or spatial resolution is made possible.

Abstract: The present invention includes a fully programmable plurality of multi-channel receivers, each receiver having a digital multi-channel receive processor and a local processor control. Each receive processor includes a first decimator, time delay memory, second decimator, and complex multiplier. The receive beamformer is a computationally efficient system which is programmable to allow processing mode trade-offs among receive frequency, receive spatial range resolution, and number of simultaneous beams received. Each local control receives focusing data from a central control computer and provides final calculation of per-channel dynamic focus delay, phase, apodization, and calibration values for each receiver signal sample. Further, this invention includes a baseband multi-beam processor which has a phase aligner and a baseband filter for making post-beamformation coherent phase adjustments and signal shaping, respectively.

Abstract: An ultrasound imaging system is programmed to acquire first ultrasonic image frames intermittently. These first frames, typically triggered frames synchronized with a selected portion of an ECG cycle, are optimized for high image quality of a contrast agent included in the tissue. The imaging system automatically acquires second ultrasonic image frames between at least some of the first frames. The second image frames are typically locator frames which are optimized for reduced degradation of the contrast agent. More of the second frames are acquired per unit time than first frames, and both the first and second frames are displayed, either superimposed over one another or in side-by-side relationship. In this way the user is provided with substantially continuous transducer locating information, yet contrast agent destruction between acquisitions of the first, triggered frames is reduced or eliminated.

Abstract: An ultrasonic imaging system and method provide whitening using a two dimensional pre-detection filter followed by low pass filtering using a two dimensional post-detection filter to reduce speckle variance and enhance spatial resolution of the resulting image.

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: An ultrasonic method and system for boundary detection of an object of interest in an ultrasound image is provided. One ultrasound imaging system that is provided acquires an ultrasound image from a subject using harmonic information and automatically generates a boundary oriented with respect to an object of interest in the ultrasound image. Another ultrasound imaging system that is provided receives a plurality of user-proposed transition positions oriented with respect to an object of interest in an ultrasound image and automatically generates a computed boundary oriented with respect to the object of interest at least partially as a function of the plurality of user-proposed transition positions. The ultrasound image used in this system can be generated with received ultrasonic energy at a fundamental frequency or at a harmonic of the fundamental frequency.

Abstract: A transmit beamformer includes multiple transducers, each responsive to a respective transmit waveform to produce a respective transducer waveform. A transmit waveform generator generates the transmit waveforms, and the transmit waveform each include multiple frequency components. Progressively higher frequency components of the transmit waveform are timed to cause corresponding progressively higher frequency components of the transducer waveforms to focus along a line at progressively shorter ranges. In this way, a frequency dependent line focus is achieved.

Abstract: A method and system for ultrasonically imaging a target with energy spreading transmissions is provided. Simultaneous and sequential compound point, line and combination point and line focusing is used with harmonic receive processing. Ultrasonic energy focused at multiple depths is transmitted at the target. The target may or may not include contrast agents. In either case, echoes of the transmissions at one or more fundamental center frequencies are received at harmonics of the fundamental frequencies.

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: 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: An ultrasonic imaging device for imaging the middle and inner ear is here described. It includes a thin, flattened shaft, a deformable support structure, a mounting surface, and an ultrasonic imaging array. Imaging is effected by the introduction of an acoustically conductive fluid into the middle ear space. Access to the tympanum through the external auditory canal and adjacent to the probe shaft for the purpose of injecting fluid into the middle ear space both before and during the exam is permitted by the flattened probe shaft. The deformable probe shaft may be bent or angulated to best fit a particular patients ear thus permitting optimal access for imaging through the tympanum and around the manubrium of the malleus attached down the midline of the tympanum. High resolution imaging of all structures within the middle and inner ear is achievable.

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: An ultrasound system and method are provided for improving resolution and operation. The system applies different imaging parameters within and outside a region of interest in an ultrasound image to improve spatial and/or temporal resolution inside a region of interest. The system also increases an apparent frame rate within a region of interest in an ultrasound-image frame by generating a motion-compensated interpolated image based on measured motion. The ultrasound imaging system also performs a method for automatically adjusting ultrasound imaging parameters in at least a portion of an ultrasound image in response to transducer or image motion to improve spatial or temporal resolution. With the measured motion, the system can also alter an operating mode of an ultrasound transducer array in response to an absence of transducer motion. Further, the system corrects distortion in an acquired ultrasound image caused by transducer or image motion.

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.