Abstract: A continuous wave driven ultrasonic transducer for determining doppler frequency shift in reflected ultrasonic pressure waves in which the transmitter and receiver sections are constructed of a composite core having a plurality of segments of piezoelectric material separated by acoustic suppression material. Also disclosed is a method of reducing acoustic and mechanical cross coupling between piezoelectric transmitter and receiver sections of an ultrasonic transducer by arranging segments of piezoelectric material in a lateral array, and separating the piezoelectric segments with ultrasonic acoustic suppression material to produce a composite transducer core of reduced acoustic and mechanical cross coupling.

Abstract: A curved array ultrasonic transducer is manufactured by cutting a flat transducer plate, which is attached to a flexible support plate, into a plurality of segments, the segments being hingedly attached by the support plate. The support plate is bent to a radius and the conductive traces in a flexible circuit board are electrically connected to the transducer plate segments. The flexible circuit board, having a plurality of branches, is bent to a perpendicular position such that the traces in the plurality of branches become substantially aligned. The traces exiting the branches are then electrically connected to a pin and socket connector device.

Abstract: In a mechanical sector scanner, a first bevel gear is mounted on the end of an output shaft of a motor, and an ultrasonic transducer is rotatably supported for rotating about a scanning axis transverse to the output shaft. A second bevel gear engaging the first bevel gear is mounted on the back surface of the transducer. The output shaft oscillates about an output axis. Oscillations of the output shaft are coupled to the transducer by the bevel gears. The second gear has a plurality of teeth arranged in an arc less than completely around the scanning axis, and the second gear is so disposed that the back surface of the transducer is nearer to the scanning axis than the teeth.

Abstract: Ultrasonic interrogating apparatus for needle insertion has an array of ultrasonic transducers, electronics for exciting the transducers to ultrasonic emission and receiving ultrasonic echoes therefrom, a housing for the electronics having first and second ends, and a display for presenting the received echoes. The array of transducers is seucred to the electronics housing in laterally offset relationship therefrom. The passage extends through the array of transducers without extending through the electronics housing. A needle is inserted through the passage in the transducer array for the purpose of aspiration or biopsy. The passage comprises a longitudinal slot converging from end to end and a transverse slot extending laterally for the entire length of the longitudinal slot from the longitudinal slot to the side surface of the array.

Abstract: A piezoelectric crystal has a concave active surface and a high acoustical impedance. A flat layer of molded material having a low acoustical impedance faces the active surface of the crystal to form a space therebetween. An intermediate layer of molded material having an intermediate acoustical impedance fills the space between the crystal and the flat layer. Preferably, the intermediate material has a sonic velocity near that of water, and the flat layer has a uniform thickness of approximately 1/4 of the average wavelength of the ultrasonic energy emitted by the crystal. A housing supports the crystal, the flat layer, and the intermediate layer.