Abstract: A novel method for imaging body tissues is disclosed wherein an ultrasonic pulse having a radially asymmetric side-lobe pattern surrounding a central focal lobe is generated. A receiver for receiving echoes of this pulse is provided which exhibits a sensitivity to echoes from the aforementioned side-lobe pattern which is relatively decreased by comparison to its sensitivity to echoes from the central focal lobe. In the preferred embodiment, square transducers which are rotated with respect to the focal axis by about 45.degree. are used to practice the disclosed method.

Abstract: Ultrasound imaging systems such as those utilized in breast scanning and diagnosis require not only periodic maintenance but also evaluation of the resolution and depth of field capability so as to provide maximum information to the clinician utilizing the system. The resolution measuring device preferred incorporates helically contorted filaments physically arranged to intersect at a point thereby forming a known gradient of divergence. Measurement of the translational distance from the intersection point to the point of resolution of imaged lines will, with knowledge of the gradient, permit facile determination of the separation distance which corresponds to the resolution of the ultrasound imaging system.

Abstract: A novel pulse-echo ultrasound imaging system is disclosed comprising at least three transducers. A first external scanning transducer images a selected scan area of body tissue by pulsing that area with ultrasonic waves. Two additional detector-transducers are disposed at distinct locations on a probe, such as a biopsy needle, which is inserted into the body in the vicinity of the scan area. By determining the sequence of wave front arrivals at the detectors-transducers, the relative location of the probe with respect to the scan area is readily determined and indicated. Either the scanning transducer or the probe may then be maneuvered in response to such indication to ensure that the probe tip is properly positioned relative to the scan area.

Abstract: Ultrasound breast scanning and diagnosis is achieved by suspending the breast in a water pool, in which is immersed a wide aperture transducer/lens assembly. The water path is defined by two separate segments, an upper one, into which the breast is suspended, contained by a flexible sonically transparent bag member, and the lower being contained in a longitudinally movable tank which is filled to contact with the bag member portion protruding into the tank.

Abstract: Electronic means, including an analog-to-digital converter responsive to samples of the output from an analog angle sensor directly coupled to an immersed oscillated transducer, is used to trigger the energization of the transducer at each of a predetermined number of equal increments in angle position during each cycle of oscillation of the transducer, with the triggered angle positions during a certain half-cycle of oscillation being interlaced with the triggered angle position during the other half-cycle of oscillation.

Abstract: Transducer completely immersed in ultrasonic propagating liquid can be oscillated back and forth at a high rate, without producing significant turbulence in liquid, if oscillation velocity varies as a predetermined smooth continuous function of time.

Abstract: A B-scan pulse echo ultrasound system produces a real time image of a body area under inquiry, and an aspiration needle is inserted directly into that area. The needle carries a small, omni-directional ultrasound transducer, electrically connected through the needle to transponder electronics. Incident pulses from the imaging transducer to the omni-directional transducer are sensed at the latter, and the position thereof is inserted into the image either by generation of a return signal from the needle point, or through delay logic and subsequent production of a composite.

Abstract: A-wave quantification indicator automatically measures the difference in amplitude between the peak of the E-wave portion of an ultrasonically derived M-wave CRT display and the peak of the A wave portion of the M-wave. This difference in amplitude, which distinguishes myocardial-disease and hyperkinetic syndrome subjects from normal subjects, is alphanumerically displayed in quantitative and/or qualitative terms.

Abstract: Transducer completely immersed in ultrasonic propagating liquid can be oscillated back and forth at a high rate, without producing significant turbulence in liquid, if oscillation velocity varies as a predetermined smooth continuous function of time.

Abstract: A transducer comprising a longitudinal bar of piezoelectric material having one longitudinal face substantially covered with a first electrode and the opposite longitudinal face in contact with a predetermined plural number of separate electrodes spaced along the length thereof, permits all detected echoes to be processed by a single low input impedance amplifier permanently coupled to the first electrode.

Abstract: A transducing unit comprising a central section, detecting echoes returned through only a small portion of a relatively large aperture lens, surrounded by an annular section, detecting echoes returned through the remainder of the aperture, provides detected signals from the respective central and annular sections which are selectively utilized during respective specified time intervals in accordance with the operation of time-controlled switches to thereby change the effective depth of focus of the lens as a function of time.

Abstract: A method and apparatus for directly obtaining displacement-amplitude information from a quadrature-dual interferometer. The system uses a "mini-wiggler" to introduce phase shift into the reference beam, as by oscillating a reference mirror with a piezo-electric crystal. The mini-wiggler produces relatively small phase perturbations of the order of 0.001.lambda. at a frequency at either edge or in the middle of the signal frequency band. The system uses a signal-processing circuit to obtain displacement amplitude directly. The purpose of the mini-wiggler is to produce a "pilot" signal of known amplitude and phase from which the correction terms needed to compensate for variations in the interferometer state, such as those caused by vibration, large variation, drift, and the like, are derived and can be applied by means of another signal processing circuit.

Abstract: Disclosed is a random phase diffuser which is inserted between a transducer and an insonification subject in accoustical imaging. The diffuser is comprised of an array of lossless elements which cause sound emitted by the transducer to be passed through and emitted with a phase value of 0.degree. or 180.degree.. Additionally disclosed is the combination of a random phase diffuser with a wedge coupling feature for increasing insonification efficiency.

Abstract: An improved pulse-echo ultrasonic-imaging system for scanning, in real time, objects such as soft tissue within a living human body. It employs a transducer including first and second parallel wave-energy generating electrodes extending linearly in a first direction and a linear array of image-spot detecting electrodes also extending in this first direction and is situated half-way between the first and second electrodes. Scanning in a second direction orthogonal to the first direction is provided by counter-rotating Risley prisms rotating at a predetermined rate. The distance between each of the first and second electrodes and the linear array is related to this predetermined rate such that reflected wave energy is always directed to the linear array.