Abstract: Techniques for underwater detection of fully or partially buried objects such as sea mines and underwater cables are disclosed. An acoustical camera produces three dimensional volumetric images of a target area volume of an underwater floor. One or more first images are produced of the target area volume. An acoustical transducer pulse is then directed to the target area volume so as to disturb the loose particulate or elastic matter included in the target area. One or more second images are then produced while the pulse is present in the target area volume. The images can be compared for evidence of buried objects, or to otherwise evaluate objects included in the target area. The camera can be configured with an interferometer mode so as to produce volumetric images at a real-time frame rate.

Abstract: Techniques for interconnecting high-density, structures that include temperature sensitive materials such as piezoelectric ultrasonic transducer arrays, optical detector arrays, MEMS and the like to other structures (e.g., integrated circuits or mechanical assemblies) are disclosed.

Abstract: A high density, exceptionally complex and compact ultrasound transducer array using multi-layer structures composed of active integrated circuit devices on various substrates and passive devices. Electrically conducting interconnections between substrates are implemented with micro-vias configured with conductors extending through the substrates, permitting the use of divided or different integrated circuit technologies arranged and/or isolated within different integrated circuit substrates or layers of the ultrasound transducer assembly. The various layers may be assembled with solders of respectively lower reflow temperatures, to permit testing of selected layers and circuits prior to completion.

Abstract: A transducer probe has a fully populated, integrated, matrix array of acoustical transducers for ultrasound imaging. The transducer arrays include tiled subarrays of transducers which may be switched (e.g., in real-time) between vertical and horizontal modes, and may further be configured to perform a first level of transmit and receive beam forming functionality with either horizontal or vertical scanning. Example applications include medical imaging, materials testing, and sonar systems.

Abstract: A real-time, three dimensional, acoustical camera and a real-time, range-gated, intensified, electro-optical camera have substantially overlapping fields of view for co- registered imaging of underwater objects at close ranges. The system is typically mounted in an unmanned underwater vehicle but may be used in other fixed or mobile configurations. The coupled fields of view are steerable in an arc around at least one axis over a large field of regard with a servo-controlled rotating mirror system, while the vehicle or the target is moving or hovering. An automated target recognition system uses the multi-modality images to provide enhanced target recognition and/or autonomous operation in unmanned missions.

Abstract: A method and system for underwater detection of fully or partially buried objects such as sea mines and underwater cables, consisting of a mobile underwater platform configured with a real-time, three dimensional acoustical camera with a downward directed field of view used as an imaging interferometer, coordinated with a high-intensity, low frequency acoustical transmitter directed as to disturb the loose particulate or elastic matter comprising the seafloor within the field of view of the camera. The images recorded by the camera display the relative motion of the seafloor material before and after an acoustical pulse, in contrast to the lesser or no motion of submerged solid objects. Distinguishing man-made from natural objects is aided by recognizing geometric shapes apparent within the varying image density, not common in nature.

Abstract: A transducer probe has a fully populated, integrated, matrix array of acoustical transducers for ultrasound imaging, switchable in real time between two orthogonal 1.5D or 1.75D transducers arrays, consisting of tiled subarrays of transducers which may be switched in real time between vertical and horizontal strip arrays by integrated circuits directly attached to the subarrays, for performing a first level of transmit and receive beam forming functionality with either horizontal or vertical scanning. The integrated circuits include a summer circuit for reducing the output signals of each subarray to a single line, reducing the number of lines required in the cable or connection medium. An interface box mates to a host system and facilitates the switching and control function. Impedance matching in the integrated circuits between transducers and cable lines improves signal transmission in cables. Applications include medical imaging, materials testing and sonar systems.

Abstract: An integrated piezoelectric ultrasound array structure configured to minimize the effects of differential thermal expansion between the array and the integrated circuit and to improve the mechanical and acoustical integrity of the array. The transducer array may have an interposed thinned supporting substrate and is matched to the integrated circuit substrate for thermal expansion so as to retain mechanical integrity of the array/IC bond within the working temperature range. Transducer elements are laterally isolated acoustically and as to thermal expansion by air or other acoustically attenuating medium of lower elastic modulus material between the elements. Acoustical effects are vertically acoustically isolated with capacitive coupling and small area solder bumps relative to wavelength, and further laterally acoustically isolated by thin supporting substrates relative to wavelength, including thinned semiconductor integrated circuit substrates.

Abstract: A transducer probe has a fully populated, integrated, matrix array of acoustical transducers for ultrasound imaging, switchable in real time between two orthogonal 1.5D or 1.75D transducers arrays, consisting of tiled subarrays of transducers which may be switched in real time between vertical and horizontal strip arrays by integrated circuits directly attached to the subarrays, for performing a first level of transmit and receive beam forming functionality with either horizontal or vertical scanning. The integrated circuits include a summer circuit for reducing the output signals of each subarray to a single line, reducing the number of lines required in the cable or connection medium. An interface box mates to a host system and facilitates the switching and control function. Impedance matching in the integrated circuits between transducers and cable lines improves signal transmission in cables. Applications include medical imaging, materials testing and sonar systems.

Abstract: A high density, exceptionally complex and compact ultrasound transducer array using multi-layer structures composed of active integrated circuit devices on various substrates and passive devices. Electrically conducting interconnections between substrates are implemented with micro-vias configured with conductors extending through the substrates, permitting the use of divided or different integrated circuit technologies arranged and/or isolated within different integrated circuit substrates or layers of the ultrasound transducer assembly. The various layers may be assembled with solders of respectively lower reflow temperatures, to permit testing of selected layers and circuits prior to completion.

Abstract: An ultrasonic camera having a high efficiency ultrasonic lens is coupled to a ultrasonic transmitter/receiver by a stretched membrane interface. The ultrasonic lens provides highly efficient transmission of ultrasound without introducing aberrations. The ultrasound system also uses a quasi incoherent source to reduce speckle noise in the image.

Abstract: A forward-scanning ultrasound catheter probe. An ultrasound catheter probe includes a forward-scanning transducer positioned at the tip of the probe. As such, the forward-scanning transducer may provide images of structures that may lie ahead of the tip of the probe. Furthermore, the forward-scanning transducer is repositioned by a drive mechanism coupled to the front-scanning transducer to provide a sector scan. In one embodiment, a bimorph piezoelectric drive is utilized to sweep the forward-scanning transducer across an arc to provide an imaging area associated with a sector scan.

Abstract: An ultrasonic camera having a high efficiency ultrasonic lens is coupled to a ultrasonic transmitter/receiver by a stretched membrane interface. The ultrasonic lens provides highly efficient transmission of ultrasound without introducing aberrations. The ultrasound system also uses a quasi incoherent source to reduce speckle noise in the image.

Abstract: An array of ultrasonic transducers, where each of the ultrasonic transducers has a matching layer end and a driving layer/individually isolated end. A bump bond connects each one of the ultrasonic transducers to a substrate. A high voltage electrical conductor is connected to at least one driving layer/individually isolated end to provide a drive signal to at least one of the ultrasonic transducers. A conductive/matching layer is disposed to electrically connect each matching layer end. An outer matching layer is connected to the conductive/matching layer. The bump bond is an indium or solder bump bond having a contact area for contact with an ultrasonic transducer less than 20 percent of the driving layer/individually isolated end for the contacted ultrasonic transducer so as to provide mechanical stability while reducing cross talk among the plurality of ultrasonic transducers.

Abstract: An ultrasound imaging system for performing dynamic focusing of ultrasonic waves during transmit and receive. The present invention includes a method and a means for transmitting ultrasonic waves to a multiple depths within a body. The present invention optimizes the transmit frequency for each of the multiple depths to localize the energy of the ultrasonic waves. The present invention also includes a method and means for performing dynamic receive focusing of the reflected ultrasonic waves produced by discontinuities in the body, such that it is focused to receive ultrasonic waves from the depth at which the transmitted ultrasonic waves are focused.

Abstract: An array of ultrasound transducers for pulsed sector-scan operation includes a plurality of transducer elements disposed on an arc of a circle and oriented to emit and receive ultrasound radiation in the direction of the center of the arc. A group of adjacent transducers within the array is active for each ultrasound pulse. The position of the group in the array is incrementally shifted along the arc, one transducer at a time, to effect scanning. The inherent focussing effect of a curved group of transducers is compensated with time delays or a negative lens to provide a parallel, sector-scanned radiation beam.

Abstract: An acoustical imaging system wherein an acoustic beam projected through a transmission medium is modified (scattered) by a subject therein and impinges upon one side of an acousto-optic interface. The other side of this interface is made concave and mirror-surfaced to reflect an illuminating laser beam. The acousto-optic interface is "composite," being fabricated from an epoxy matrix with a multitude of tiny spherular capsules, or "microballons" distributed therein to thereby match the acoustic impedance of this interface to that of the transmission medium.

Abstract: Erasable thermoplastic image recording systems having extended useful lifetimes are provided by subjecting the thermoplastic recording medium to a sequence of erasure, exposure to incident radiation cooling and projection in an inert atmosphere while applying corona charge throughout the erasure and exposure cycles. By exposing at a time when the medium is cooling from the erasure step, a heat development step is eliminated which eliminates nearly 50% of the thermal degradation of the thermoplastic polymer. Exclusion of oxygen from the system eliminates the considerable chemical degradation the film suffers from reaction with ozone. Erasure in the presence of a uniform corona charge provides more complete erasure than standard procedures. Lower temperature and shorter heating pulses are permitted with a lower surface tension thermoplastic polymer provided by external plastization of the thermoplastic. The lower surface tension also results in less noisy images and greater lifetimes.