Abstract: An apparatus of the present invention includes: a container operable to hold a liquid; circuitry operable to provide an electrical stimulus; and a piezoelectric element electrically coupled to the circuitry. The piezoelectric element includes a first face positioned beneath the liquid when the liquid is placed in the container, the piezoelectric element being responsive to the electrical stimulus to produce acoustic energy that causes droplets to form from the liquid. The piezoelectric element has a focal length along a focal axis intersecting the first face. The piezoelectric element and the container are structured in relation to one another to form an oblique angle between the focal axis and an axis generally parallel to a surface of the liquid when the liquid is at rest in the container.

Abstract: A tissue ablation apparatus is disclosed that includes an elongate, flexible device operable to be percutaneously place in vasculature of a patient. The device has an array of 8 or more tissue ablation elements carried on a flexible circuit substrate located at a distal end portion. A cable is also included that has a number of electrical conductors insulated from one another that are each electrically coupled to a different one of the elements. One or more connectors are electrically coupled to the cabling at a proximal end portion of the device.

Abstract: In one embodiment, an endoscope has a proximal end portion opposite a distal end portion. A view port is included at the distal end portion to view an internal body region through a passageway of a patient's body. Also located at the distal end portion are one or more piezoelectric elements operable in one mode to determine position of the distal end portion relative to internal body region and operable in a second mode to ablate tissue of the internal body region. The endoscope carries a balloon positioned about the one or more piezoelectric elements to selectively hold the distal end portion in a desired position in the passageway.

Abstract: One embodiment of the present application includes providing an array ultrasound imaging phase assembly that includes a substrate and several piezoelectric elements each mounted on the substrate. The elements are spaced apart from each other and arranged in a noncylindrical pattern. An acoustic backing block is mounted to the substrate on a side opposite its matching layers. The array can be positioned along a desired region within a subject's body by movement through the circulatory system or other cavities. While the array assembly is positioned along this region, ultrasonic interrogation of an internal portion of the subject's body can be performed to generate one or more images.

Abstract: An ultrasound transducer array probe for intraluminal ultrasound imaging is situated on a distal end of a catheter. The probe has a flex circuit that accepts terminations from a plurality of coaxial cables admitted through the catheter, and electrically conveys these signals to integrated circuits and an ultrasound array acoustic stack, preferably having seventy-two elements. The circuit has more than one layer of metal tracings to support complicated electrical interconnections. The acoustic stack preferably includes two quarter-wave matching layers and an acoustic backing layer composed of urethane, AIN.sub.3, tungsten trioxide, and micro-balloons. The flex circuit can be formed of two sections that are joined during manufacture.

Abstract: An ultrasound mixed signal multiplexer/pre-amplifier application specific integrated circuit (ASIC) for supplying voltages to a group of elements of an ultrasound array, receiving voltages from the same or another group of elements of the array, and amplifying the received voltages for transmission to external circuitry. The transmit groups and receive groups are shifted to provide accurate visual images with a minimal number of transmit and receive cycles.

Abstract: A highly efficient piezoelectric transducer suitable for medical applications is disclosed which exhibits a 40 db ring down time of less than 3 cycles, that is, of less than 0.7 microsecond at 4.2 MHz. The subject transducer comprises a single crystal lithium niobate active element which is supported on a formed backing material which is lapped to a surface flatness of better than 0.0002 inches (0.0015 cm). The subject transducer, which is designed to be driven at 4.2 MHz further comprises a first matching layer having an impedance of 6.8-7.4.times.10.sup.6 kg/m.sup.2 sec and a second matching layer having an impedance of between 1.8-2.4.times.10.sup.6 kg/m.sup.2 sec. An alternate embodiment dual-power transducer is also disclosed which is suitable for operating at different power levels to selectively image or produce lesions in selected body tissues.

Abstract: A solid steel stylet is carried coaxially within a hollow biopsy needle. The stylet carries a matching layer at its tip, such that when the needle and stylet are inserted into the body, ultrasound energy impinging on the needle tip is converted to pressure waves which are conveyed back up the stylet. An ultrasound transducer located outside the body is coupled to receive sonic energy from the stylet, and to convert it to electrical energy for coordination with, and superposition upon the image of the system.