Abstract: An ultrasound transducer and the method for the manufacture thereof which is designed to reduce the generation of elevational sidelobes. At least one kerf is formed in each end region of a body of piezoelectric material. The kerfs define therebetween a center region formed solely of piezoelectric material. The kerfs are filled with a second material.

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: A method and device for ultrasonically imaging a body that includes a movable ultrasonic transducer capable of imaging a scanline wherein the scanline is fixed in orientation and spatial position relative to the movable transducer. The device contains a means for sensing transducer position information wherein the sensing means is in communication with an ultrasound console. A computing means computes the spatial position and the orientation of each scanline as the transducer is moved. The scanlines are then presented as a complete image. Alternatively, an electromagnetic transmitter and receiving sensor determine the spatial orientation and position of each scanline in free space. The method of generating a two dimensional ultrasonic image is also disclosed.

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: A phased array transducer for an ultrasonic imaging system includes a flexible support element which supports an array of piezoelectric transducer elements. Shape transducers such as strain gauges or capacitive transducers are coupled to the support element to generate a signal indicative of the instantaneously prevailing curvature of the array. A user-controlled actuator is coupled to the support element to flex the support element between at least first and second configurations, wherein the support element has separate curvatures along the axis of the transducer in each of the first and second configurations. In some applications the transducer elements are positioned for separate scan formats in the first and second configurations. The support element can be provided with first and second alternating regions which differ in flexibility, in order to concentrate flexing of the support element in the second regions.

Abstract: An ultrasound transducer having an elevation profile or surface geometry for focusing various frequency ultrasound beams at various focal points. The elevation profile or surface geometry is defined by at least two different geometries.

Abstract: An ultrasonic receive beamformer includes transducers forming receive signals that are applied to sub-array processors. Each sub-array processor includes at least one phase shifter and a summer, and each phase shifter is responsive to at least one of the transducer signals to shift the transducer signal by a respective phase angle and to apply the phase shifted transducer signals to the summer. Each of the summers supplies a summed sub-array signal to a respective beamformer processor. The phase angles for any one of the sub-array processors form a sum substantially equal to zero. Furthermore, the phase angles for any one of the sub-array processors are independent of the time delay of the respective digital beamformer processor. The time resolution of the time delay of the digital beamformer processors is substantially as fine as the time resolution of the phase angles of the phase shifters.

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 transducer array for transmitting and receiving ultrasonic energy in multiple two-dimensional imaging planes. The ultrasonic energy in the imaging planes is focused in elevation by the curvature of the transducer array. An imaging plane is selected from a plurality of available imaging planes by electronic switching. Each imaging plane when selected is positioned at a known angle, different from all other imaging planes, due to the known curvature of the transducer array, and the known dimensions of the transducer elements.

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: An ultrasound transducer includes transducer segments having a non-uniform thickness layer of relaxor ferroelectric material and coupled to a source of biasing voltage thereto. The elevational aperture is controlled by varying biasing voltage applied to the layer of relaxor ferroelectric material.

Abstract: A phased array transducer and method for the manufacture thereof having a design that allows the array to focus in a near field of interest and a far field of interest. The array includes a plurality of even and odd numbered transducer elements where the even and odd numbered elements have an active region of particular widths. The width of the active region of the odd numbered elements is different than the width of the active region of the even numbered elements so that the odd numbered elements can be used to image in one field of interest while the even numbered elements can be used to image in another field of interest.

Abstract: The invention provides a method and system for estimating missing Doppler signals and spectra in an ultrasound imaging system: (1) parameters representative of a Doppler data model are matched to actual Doppler data that is received; (2) the parameters are interpolated or extrapolated (possibly after normalization, smoothing, or other manipulation) for regions where actual Doppler data is missing ("Doppler gaps"); and (3) a set of synthesized Doppler spectra are constructed, using the model and the interpolated or extrapolated parameters, for those Doppler gaps. The Doppler data model is an autoregressive model, or another model in which the Doppler data may be approximated by supplying a source signal to an autoregressive filter. The parameters of the model comprise a set of autoregressive filter coefficients and a .sigma..sup.2 (variance) value. The reflection coefficients of these autoregressive filter coefficients are determined. The reflection coefficients and .sigma..sup.

Abstract: There is provided a two-dimensional array for use in an acoustic imaging system which comprises a plurality of transducer segments each having a trace for exciting an electrode on each of the transducer segments, the trace and the electrode being formed of the same material. The two-dimensional array disclosed is capable of imaging deeper in the human body at higher frequencies and provides more reliable lead attachments to the respective segments forming the array. Methods of manufacturing the two-dimensional array are further provided.

Abstract: An apparatus and method for automatically controlling rotation of a transducer that is mechanically coupled to a motor are disclosed. The apparatus includes a motor controller coupled to the motor and a microprocessor. The motor controller includes a state-machine and an encoder. The microprocessor is coupled to the state-machine. Two methods for automatically controlling rotation of an ultrasound transducer are disclosed. The first method includes the steps of providing a microprocessor coupled to a motor controller, the motor controller comprising a state-machine and a speed setting circuit, and initializing the state-machine by providing a desired speed and a target position from the microprocessor. The first method further includes the step of automatically selecting the desired speed from the speed setting circuit in accordance with the initialized state-machine. The first method further includes rotating the ultrasound transducer at the selected speed.

Abstract: According to the present invention, an ultrasonic transducer probe is provided having an array of ultrasonic transducers rotatably mounted about an axis within the ultrasonic transducer probe, a lens mounted to the array, and a housing encasing the array and the lens. The lens is symmetric about the axis of rotation of the array. In addition, the housing has a continuous upper surface that is formed, in a region adjacent to the symmetric lens, to mate with the symmetric lens.

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: An ultrasonic transducer is rotated until the displayed vessel has the smallest area. The transducer is then tilted to various angles with respect to a normal to a surface to obtain area and velocity measurements of fluid flow inside a vessel in a body imaged. A least mean square error calculation is then performed to find the area and velocity that will minimize such error. The product of these two quantities is the estimated flow.

Abstract: A modular transducer system includes a small, hand held adapter which remains permanently attached to an ultrasound system console and permits the rapid connection and disconnection of individual, sterilizable ultrasound transducers. In a preferred embodiment, the hand held adapter is connected to the system by a retractable cable. In another preferred embodiment, the individual transducers are identifiable by the system using transducer generated binary codes. The individual transducers are submersible in a wide variety of liquids including cleaning solutions and disinfectants. The small transducers are easily stored at the site of the ultrasound examination. Bulky, awkward, time consuming cables and connectors are eliminated.