Abstract: According to various embodiments, an array of elements forms an artificially-structured material. The artificially-structured material can also include an array of tuning mechanisms included as part of the array of elements that are configured to change material properties of the artificially-structured material on a per-element basis. The tuning mechanisms can change the material properties of the artificially-structured material by changing operational properties of the elements in the array of elements on a per-element basis based on one or a combination of stimuli detected by sensors included in the array of tuning mechanisms, programmable circuit modules included as part of the array of tuning mechanisms, data stored at individual data stores included as part of the array of tuning mechanisms, and communications transmitted through interconnects included as part of the array of elements.

Abstract: A piezoelectric or electrostrictive composite exhibiting anisotropic 3-3 connectivity with a dense ceramic phase and an infiltrate polymer phase. The ceramic phase is an interconnected ceramic lamelli structure that is arranged substantially parallel in one direction. The ceramic lamelli have greater connectivity in the z direction than in the x and y directions, while the connectivity in the x and y directions are essentially equal.

Abstract: The present invention discloses a high density interconnect for an ultrasonic phased array and method for making. The high density interconnect includes a backfill material having grooves formed therein. Each of the grooves are separated a predetermined distance from each other and have a predetermined groove depth. A conducting material is deposited in each of the grooves. The grooved backfill is cut or formed into sections having different lengths. The sections are then reconsolidated into an unitary structure, wherein one end of the structure is electrically conductive in one direction. One surface of the high density interconnect is metallized for bonding with an ultrasonic phased array transducer while the other side is patterned with solder bumps for connection to integrated circuit boards or flexible circuit boards.

Abstract: A multiplanar ultrasonic probe incorporates a mechanically rotatable linear phased transducer array. The transducer array can be remotely maneuvered to change the scan plane. A ring gear affixed to the transducer array surrounds the transducer array and is concentric with the axis of rotation. The ring gear is engaged and rotated by an indexing mechanism in incremental angular steps in either the clockwise or counterclockwise direction. The indexing mechanism includes a ratchet mechanism displaceable along a line between first and second positions from a neutral position intermediate the first and second positions. The ratchet mechanism carries a pair of pawls, one of which engages the ring gear to cause clockwise rotation and the other of which engages the ring gear to cause counterclockwise rotation. The ratchet mechanism is displaced by actuators such as bimorphic devices, made of piezoelectric material, which bend in response to electrical pulsing.

Abstract: An improved two-dimensional ultrasonic transducer array is provided by forming a plurality of elongated transducer strips each including a central body of piezoelectric material having mounted thereon a conducting inner matching layer and outer matching layer, a conducting inner backing layer and a nonconducting lossy outer backing layer, depositing a conducting film on the outer surface and one side surface of the outer matching layer and into electrical contact with the conducting backing layer of each strip and depositing a plurality of conducting films in space relation to one another on the back surface and one side surface of the lossy backing layer and into electrical contact with the conducting backing layer to provide an electric circuit to the front and back faces of the piezoelectric layer.

Abstract: This invention relates to soldering systems of the type that provide localized soldering through the use of lasers. Such structures of this type generally allow flexible printed circuit boards to be locally soldered to metallized ceramic substrates. These structures have applications in such areas as ultrasound equipment.

Abstract: A cryogenic solid-state semiconductor power device, has the actual device chip mounted on a substrate of a material of very high thermal conductivity, which is positioned in a a bath of cryogenic fluid. The substrate may be formed of beryllia, beryllium, alumina, aluminum nitride, diamond and the like materials.

Abstract: In a phased array acoustic transducer which has elements of different sizes, the piezoelectric material of large elements is subdiced to produce smaller segments to limit the overall piezoelectric segment size variation within the array to up to 55% or more without significant adverse effect on phased array processsing.

Abstract: A piezoelectric ultrasonic array transducer has its individual elements connected to external electronics via a high density interconnect structure which facilitates signal connection and uniformity from array-to-array. The array fabrication process is preferably modified for use with a high density interconnect structure in order to obtain maximum transducer quality.

Abstract: An ultrasonic imaging system has a probe with an even-numbered plurality of N of transducer elements, with one transducer element being present in each of a like plurality N of signal-processing channels, and with successive ones of the transducers polarized in alternating directions. The transducers require channel excitation drive signals which are either a positive-polarity pulse or a negative-polarity pulse, with signal polarity being dependent upon the polarity of the transducer in the particular channel. The processed outputs of each odd channel is connected directly to an associated input of a coherent summer while the processed output of each even channel is individually amplitude-inverted before connection to an associated summer of input. The summation means output is the sum of all channel transducer outputs, with suppression of any common-mode signal appearing anywhere in the system channels, from the transducer to the summation means inputs.

Abstract: An ultrasonic imaging system probe with an even-number of transducer elements, has a transformer for coupling the received signal from each transducer to an associated cable. The polling of the transformer primary windings are identical while the polling of the secondary windings of the transformer alternate, i.e. are reversed for all even-numbered channels, with respect to odd-numbered channels. All odd channel outputs are conected to a first signal bus, while all even channel outputs are connected to a second signal bus. The signal busses are connected to inputs of a differential-input amplifier, having an output which provides the sum of all channel transducer outputs, with suppression of any common-mode signal appearing in the system from the channel transformer secondary windings to the differential amplifier inputs.

Abstract: A two-dimensional ultrasonic phase array is a rectilinear approximation to a circular aperture and is formed by a plurality of transducers, arranged substantially symmetrical about both a first (X) axis and a second (Y) axis and in a plurality of subarrays, each extended in a first direction (i.e. parallel to the scan axis X) for the length of a plurality of transducers determined for that subarray, but having a width of a single transducer extending in a second, orthogonal (the out-of-scan-plane, or Y) direction to facilitate dynamic focussing and/or dynamic apodization. Each subarray transducer is formed of a plurality of sheets (part of a 2-2 ceramic composite) all electrically connected in parallel by a transducer electrode applied to juxtaposed first ends of all the sheets in each transducer, while a common electrode connects the remaining ends of all sheets in each single X-coordinate line of the array.

Abstract: A radio-frequency (RF) spectrometer subsystem, for a nuclear magnetic resonance spectroscopy and imaging system, provides high-power RF pulse signals each having an envelope of minimum distortion; a portion of the actual RF magnetic field, in the sample-examination volume, is returned to the spectrometer for subsequent correction of the RF signal characteristics responsive to a comparison of the RF magnetic field sample waveform to the requested pulse envelope waveform.

Abstract: Power line interference artifacts in a magnetic resonance image are minimized by the process of: providing a sequential plurality of imaging signal sequences, the totality of which sequences is required for determining the value of each image pixel in an image array thereof; requesting the start of each sequence of the plurality of imaging signal sequences prior to the actual time at which each such signal sequence should commence; preparing a recognition element prior to the desired actual commencement time; recognizing a predetermined occurrence of a repetitive power line signal parameter to provide a first signal; setting the recognition element responsive to the first signal to only then cause the signal sequence start request to actually cause commencement of the associated signal sequence; and causing each signal sequence to occur in essentially an integral number of sequential repetitive cycles of the power line signal waveform to minimize the magnitude of power line frequency signal interference artif

Abstract: A radio-frequency shielded room for a nuclear magnetic resonance imaging system has at least one electrically-conductive shield wall substantially enclosing a predetermined volume adjacent to one end of the bore formed through an imaging magnet within which bore the imaging process is carried out. The at least one wall has an aperture therethrough substantially at and in registration with the one bore end. A hollow shield member, of an electrically-conductive material, extends through the magnet bore and has a first end region periphery aligned with and substantially electrically connected to the entire periphery of the aperture in the at least one wall. A second end of hollow shield member extends at least to the remaining end of the magnet bore, where it is enclosed with an electrically-conductive cap substantially electrically connected about the entire periphery of the hollow shield member second end.

Abstract: The radiation pattern of shaded single element piezoelectric transducers and transducer arrays has reduced side lobe levels. Shading to reduce the intensity of emitted ultrasound at the edges of the transducer relative to the center is realized by varying the electric/acoustic conversion efficiency or polarization of the piezoelectric material, by having different mechanical element lengths, by selectively poling the piezoelectric material to produce poled and unpoled regions, and by control of electrode geometry. The shading of a phased array ultrasonic transducer is described in both lateral dimensions.

Abstract: The ultrasonographer changes the frequency of ultrasound pulses emitted from an ultrasonic transducer as a result of adjusting the RF frequency of the transmitter burst exciting the broadband transducer; this adjustment takes place between pulse transmissions, while examining the patient. In a phased array imager utilizing baseband processing of received echo signals, the same adjustment supplies the corresponding frequency to the demodulator circuits. An alternative method of changing the system spectrum is to have a narrow bandwidth receiver whose center frequency is varied over the available bandwidth.

Abstract: A linear array for rectilinear and sector scan imaging has identical approximately diamond-shaped transducer elements fabricated by making two pairs of straight line cuts at small angles through a piezoelectric slab. The Y-axis radiation pattern (parallel to element length and perpendicular to the array length) has lower side lobe levels than equal sized rectangular elements. No changes in the imager electronics among channels is required, and the shading function may be modified by changing only the transducer.

Abstract: An ultrasonic transducer has two impedance matching layers bonded to the transducer element which have different thicknesses and are 90.degree.-100.degree. and 35.degree.-55.degree. matching layers. This structure has a high sensitivity comparable to a broadband front surface matched transducer with quarter wavelength (90.degree. and 90.degree.) matching layers, and has primarily a single resonant mode so as to be suitable for relatively narrow band applications.

Abstract: A system and method are disclosed for monitoring the acoustic intensity of ultrasonic energy applied to a body by an ultrasonic probe for the purpose of diagnosing an internal target. The probe contacts a limited area of the body skin and a coupling medium, such as a coupling gel, is interposed to enhance acoustic coupling between the probe and the skin. A thermally sensitive agent in the coupling medium imparts color to the latter indicative of the heat dissipated on the skin area under the probe. Whenever a predetermined color change of the coupling medium indicates that the heat dissipation on this area exceeds a predetermined limit, the acoustic intensity of the ultrasonic energy beamed to the target is reduced.