Abstract: An ultrasound imaging system (102) includes a transducer array (108) with a two-dimensional array of rows (110) of transducer elements (114). The transducer elements of each row extend along a long axis (116). The rows are parallel to each other. The transducer array includes a non-rectangular set of active transducer elements. The ultrasound imaging system further includes transmit circuitry (118) that actuates the transducer elements to transmit an ultrasound signal. The ultrasound imaging system further includes receive circuitry (120) that receives echoes produced in response to an interaction between the ultrasound signal and a structure and received by the transducer elements. The ultrasound imaging system further includes a beamformer that processes the echoes and generates one or more scan lines indicative of the structure.

Abstract: An ultrasound transducer cover (100) includes a base (202), including an acoustically transmissive membrane (110) with first and second opposing sides. The cover further includes walls (204, 206) protruding from the base in a same direction away from the first side of the base, forming a cavity about the acoustically transmissive membrane with a geometry that conforms to a geometry of a probe head of an ultrasound apparatus housing a transducer array and a corresponding acoustic window. The cover further includes an acoustically transmissive adhesive (108) disposed on the membrane in the cavity, wherein the acoustically transmissive adhesive maintains the cover on the ultrasound apparatus in response to installing the cover on the ultrasound apparatus.

Abstract: A distortion measurement system for measuring distortion as low as 0.002% includes an ultra low distortion oscillator having a relatively fast response which is achieved by switching the time constant of the control loops of the oscillator during settling. The analyzer section included in the distortion system has a unique notch filter which provides low distortion. This is achieved by adding together two 90.degree. all pass phase shifters. In addition, automatic tuning is provided by two feedback control loops; one is responsive to out-of-phase signals which controls the RC filter circuits of the phase shifters and the other responds to the in-phase signals which controls the output summing junction of the notch filter. Finally, a feedforward type of simultaneous tuning is accomplished by ganging the oscillator frequency adjustment with the analyzer.

Abstract: Coded messages, for use in the remote control of equipment for example, are transmitted and received in a manner in which substantially precludes unauthorized or accidental activation of a control associated with the receiving means. This secure communication is accomplished by generation of a plurality of carrier frequencies in a predetermined sequence and by the modulation of each carrier frequency in accordance with a digital code. The receiving means, which is initially tuned to receive the first carrier in a transmission sequence, detects and decodes the received signals and stores the decoded message whereby equipment to be controlled may be responsive to the entire received message; the receiver being retuned to another carrier after each bit of a coded message is detected.

Abstract: A distortion measurement system for measuring distortion as low as .002% includes an ultra low distortion oscillator having a relatively fast response which is achieved by switching the time constant of the control loops of the oscillator during settling. The analyzer section included in the distortion system has a unique notch filter which provides low distortion. This is achieved by adding together two 90.degree. all pass phase shifters. In addition, automatic tuning is provided by two feedback control loops; one is responsive to out-of-phase signals which controls the RC filter circuits of the phase shifters and the other responds to the in-phase signals which controls the output summing junction of the notch filter. Finally, a feedforward type of simultaneous tuning is accomplished by ganging the oscillator frequency adjustment with the analyzer.

Abstract: A distortion measurement system for measuring distortion as low as 0.002% includes an ultra low distortion oscillator having a relatively fast response which is achieved by switching the time constant of the control loops of the oscillator during settling. The analyzer section included in the distortion system has a unique notch filter which provides low distortion. This is achieved by adding together two 90.degree. all pass phase shifters. In addition, automatic tuning is provided by two feedback control loops; one is responsive to out-of-phase signals which controls the RC filter circuits of the phase shifters and the other responds to the in-phase signals which controls the output summing junction of the notch filter. Finally, a feedforward type of simultaneous tuning is accomplished by ganging the oscillator frequency adjustment with the analyzer.