Abstract: Ultrasonic imaging is effected using a line focused transmitter 1 and a line focused receiver 3 arranged with their focal lines (f.sub.T, f.sub.R) crossing, and controlled such that the crossing point P of the focal lines scans a target to be imaged.

Abstract: An improved piezoelectric transducer permitting linear scanning along two intersecting planes. The transducer is fabricated from a cross shaped piezoelectric plate covered on both faces with metallic electrodes. First and second linear arrays are formed by the partial dicing of the opposite faces of the electrodes and plate. The two segments of the orthogonal arrays are integrated in the crossed area. An aperture may be disposed in the central area so as to permit a surgical implement, such as a biopsy needle, to be inserted into the tissue under ultrasonic visualization. Scanning electronics are alternately connectable to each of the arrays by means of a multiple pole switch under the control of a clock.

Abstract: A transmit focus generator circuit for pulsing an array of transducers in an ultrasound pulse echo imaging system for transmission of a focused beam of coherent ultrasound energy. A system clock is separated into eight phases. Focusing is achieved by controlling the clock phase delay and burst delay of transmission from each transducer element. Precalculated waveform parameters are stored in a system memory. For each line scan, registers in a transmit focus block for each transducer driver circuit are loaded with the waveform parameters. For each transducer element within the aperture for a particular line scan, the circuit controls the output of pulses to achieve a focused wavefront.

Abstract: An ultrasonic phased array imaging system is provided which includes a normal mode and an adaptive mode of operation. The adaptive mode adjusts the delay associated with each element in the transducer such that the average image brightness of the region of interest is maximized. A motion detector is provided for determining when the transducer has been moved a distance sufficient to render the previous adaptive measurements possibly invalid whereupon the system automatically reenters the normal mode. A method of operating the ultrasonic phased array imaging system is also provided.

Abstract: An apparatus for the inspection of a nuclear reactor fuel assembly in a water-filled pool having fuel rods with spaces therebetween includes an encapsulated housing having walls and being disposed in the water-filled pool. A lever drive mechanism is disposed in the housing. A rotary transmission connected to the lever drive mechanism extends through one of the walls of the housing toward the surface of water in the pool. A plurality of stationarily disposed lever linkages jut out from the rotary transmission outside the housing. Each of the lever linkages has an end facing away from the rotary transmission. Carriers are each connected to a respective one of the ends of the lever linkages. Probes are each disposed on a respective one of the carriers. Ultrasonic test heads are each disposed on a respective one of the probes for insertion into the spaces between the fuel rods.

Abstract: A system and method for measuring the acoustically induced vibrations within a living organism. The object is ensonified to set it into low frequency vibration. A continuous wave beam of ultrasonic energy is transmitted along one path and focused at the tissue to be investigated. A focused transducer receives the reflected beam along a second axis such that the intersection of the transmitted and received beams define a small, concentrated region positioned at the object under investigation. The received beam is phase modulated by the amplitude of vibration of the object producing sidebands whose amplitude can be ratioed to the amplitude of the high frequency peak to determine the absolute amplitude of the low frequency vibration.

Abstract: A robot positioning apparatus for use with robot devices having a movable portion, wherein the movable portion may be spatially oriented to, and controllably spaced from, a reference surface. Initial locating of the reference surface is accomplished by an approximate positioning subsystem using multiple, angularly oriented units which send and receive acoustic orientation positioning signals in search of the reference surface. Once a return signal is received, switching logic indentifies the necessary reorienting of the movable portion to achieve approximately the proper facing relationship of the movable portion to the surface. For precise positioning and ranging after the facing relation is established, a precision positioning subsystem emits an acoustic signal toward the surface, and a response signal is received back from the surface by at least two, and preferably three, receivers mounted upon the movable portion of the robot device.

Abstract: A method and apparatus for three dimensional imaging of a solid angular volume utilizing a single pulse of radiated energy is described. An embodiment is disclosed which utilizes a single unipolar acoustic pulse to insonify a three dimensional volume. An array of transducers is used to collect the echoes which are stored in a memory as a replica of the reflected three dimensional wavefield. This data is processed to form a replica of the three dimensional volume of objects responsible for the echoes which is then stored in a second three dimensional memory. The data in this memory is collapsed in the direction of preferred perspective to enable viewing on a cathode ray tube.

Abstract: A sectional plane of the examination subject is first scanned by focused ultrasound transmission beams in an adaptation phase. Disturbing effects from the reflected echo signals which are caused by the inhomogenities in the tissue are thereby measured. In this adaptation phase, correction values for the delay time of the signals of the elemental transducers of the ultrasound array in comparison to the standard focusing are also derived from the measured values. In a following B-image imaging phase, the delay times of the active aperture are then varied dependent on the correction values during the emission and/or during reception. The disturbing effects are thereby compensated. A method and apparatus are disclosed which are especially well-suited for linear array systems and for patients having inhomogeneous tissues.

Abstract: An ultrasonic imaging apparatus comprises an ultrasonic transducer comprised of a plurality of ultrasonic transducer elements arranged in one direction, a transmission section for driving the ultrasonic transducer to radiate first and second ultrasonic beams from the ultrasonic transducer at a time in their different directions, and a receiver section for processing echo signals which are obtained from the ultrasonic transducer means and for outputting first and second television signals. Television signals are displayed as two lines of raster on a monitor.

Abstract: In an ultrasonic imaging apparatus of the type having a plurality of selectable modes of operation, a motor-driven electroacoustic transducer is steered in a sector field in a predetermined relation to a selected operational mode. The sector scan format of returning echos is converted to a line-by-line raster display format in response to line sync pulses. The number of line sync pulses generated per unit time interval is scaled by a factor of N/M, so that it corresponds to the number of pulses generated by the encoder during the same time interval, where N and M are integers which are variable as a function of the selected mode. Phase comparison is made between the pulses generated by the encoder and the scaled line sync pulses to generate a phase difference signal from which a speed control signal is derived for controlling the speed of the motor.

Abstract: A multi-channel ultrasonic inspection system includes an ultrasonic inspection unit which generates ultrasonic inspection pulses, supplies the pulses to a part being inspected, produces an output signal proportional to the level of echo pulses received within a predetermined gate time window following generation of the inspection pulses, and generates an alarm signal whenever the output signal exceeds a predetermined gate level. The system also includes data recording apparatus having a microcomputer, a mathematics processor chip, a control panel, and a printer. A gate reference level for each channel is stored by the microcomputer by pressing a channel button on the control panel, supplying inspection pulses to a workpiece having a standard defect, and adjusting the gain or gate level of the ultrasonic inspection unit until an alarm signal is generated. The operator then presses a START button which causes the reference levels to be printed.

Abstract: Ultrasonic apparatus and methods for detecting defects in a part include a plurality of transducer channels, at least one of which is dedicated to determining the thickness of the part. An initial thickness value is determined and stored, and then subsequent thickness estimates are compared to the original thickness value and, if the estimates bear a predetermined relationship with the stored thickness value, then the thickness estimates become the new thickness values.

Abstract: An ultrasonic imaging processing system includes transducers and means to generate in an analog fashion, in-phase and quadrature phase signals. These signals are converted to digital form and a butterfly phase rotator circuit is employed to correct for phase differences in beam steering and focusing. In particular, speed and simplicity is achieved through the utilization of read only memory means providing appropriate function values for phase correction in conjunction with digital multiplication and summing circuitry.

Abstract: An echography probe wherein homogenization of the directivity of the points of the strip. The material constituting the strip possesses a coefficient of absorption which depends on the frequency. The profile of the strip is determined by the knowledge of the law of the variation of this coefficient of absorption as a function of the frequency. It is shown that the pattern of directivity of a probe fitted with a strip of this type is independent of the working frequency.The invention finds particular application in medical echography for tissue characterization.

Abstract: A method and apparatus for digitally delaying ultrasound signals, which are reflected from a boundary surface inside of an examination subject, upon reception of the signals at an ultrasound receiver employ, in each channel, a shift register, a first multiplexer, another register, and interpolator and a further multiplexer to effect a selected delay. A number of interpolated ultrasound signals is formed from two successively received ultrasound signals. If the successive ultrasound signals are shifted by .DELTA..tau., the interpolated ultrasound signals will be shifted by a smaller time difference relative to each other, dependent on the fineness of the interpolation. That interpolated ultrasound signal or that received ultrasound signal having a delay value which is closest to a selected desired delay value is employed for further signal processing. A high precision in the chronological resolution can thus be achieved with a relatively low sampling rate in comparison to the chronological resolution.

Abstract: A multi-transducer ultrasound probe including a housing having an ultrasound window with a torquer driven pulley system for positioning and oscillating a selected one of the multi-transducers in the window while activating the selected transducer.

Abstract: Ultrasonic inspection apparatus includes a linear array of transmitting transducers and a linear array of receiving transducers providing TTU mode ultrasonic inspection. One to four transmitting transducers may be simultaneously pulsed as a group, and one to four receiving transducers may be simultaneously connected in common in a group by operation of a connection circuit. The connection circuit includes a plurality of multiplexor circuits having their signal inputs connected in common to respective receiving transducers and their address terminals connected to the data output terminals of programmable read only memory devices. Calibration means are provided for correcting the output signals produced by the receiving transducers to compensate for variations in the response of individual transducers.

Abstract: An ultrasonic transducer probe assembly. The assembly includes a multiple segment transducer truncated along opposed edges to define an elongated transducer shape which is pivoted about a pivot axis coincident with the transducer. The resulting pivoting movement of the transducer allows a smaller dimension probe assembly housing with only limited diminution of control over ultrasonic depth of field and resolution. A multiconductor cable routes energizing and monitoring signals to and from the transducer array. The multiple conductors needed to carry these signals are arranged in a geometric configuration to enhance the signal carrying characteristics of the cable.

Abstract: Ultrasonic inspection apparatus includes a linear array of transmitting transducers and a linear array of receiving transducers providing TTU mode ultrasonic inspection. One to four transmitting transducers may be simultaneously pulsed as a group, and one to four receiving transducers may be simultaneously connected in common in a group by operation of a connection circuit. The connection circuit includes a plurality of multiplexer circuits having their signal inputs connected in common to respective receiving transducers and their address terminals connected to the data output terminals of programmable read only memory devices.

Abstract: An ultrasonic imaging device includes an ultrasonic probe with a plurality of vibrators arranged linearly for transmitting ultrasonic beams to an object and receiving the reflected ultrasonic beams from the object. A driving unit is constructed to control the plurality of vibrators using a time control which employs delay lines to transmit ultrasonic beams to the object in a convergent manner and to receive diverging ultrasonic beams from the object. The ultrasonic imaging device further includes a processing unit for processing the signals from the probe to obtain the reconstruction data and a display unit for displaying the reconstruction data. Since the ultrasonic beams are transmitted using the plurality of vibrators, the transmitted ultrasonic beams are strong; therefore improving the SN ratio.

Abstract: An ultrasonic measuring apparatus having an ultrasonic transducer array for transmitting ultrasonic beams and receiving echoes corresponding to the beams. The array is divided into a transmission section and a reception section. The transducer elements of the transmission section emit sequentially ultrasonic beams at a predetermined angle to a plurality of targets in a subject. The elements of the reception section receives echoes corresponding to the ultrasonic beams and coming at a predetermined angle, i.e., from the direction crossing the transmission ultrasonic beam and converts the echoes to echo signals. The echo signals are added or averaged, thereby obtaining the time which ultrasonic waves require to propagate through the subject. The sound velocity at which the ultrasonic waves travel in the subject is calculated from this propagation time.

Abstract: A robot positioning apparatus for use with robot devices having a movable portion, wherein the movable portion may be spatially oriented to, and controllably spaced from, a reference surface. Initial locating of the reference surface is accomplished by an approximate positioning subsystem using multiple, angularly oriented units which send and receive acoustic orientation positioning signals in search of the reference surface. Once a return signal is received, switching logic identifies the necessary reorienting of the movable portion to achieve approximately the proper facing relationship of the movable portion to the surface. For precise positioning and ranging after the facing relation is established, a precision positioning subsystem emits an acoustic signal toward the surface, and a response signal is received back from the surface by at least two, and preferably three, receivers mounted upon the movable portion of the robot device.

Abstract: A method and device for imaging three dimensions with a single pulse of energy is described. An embodiment is disclosed which uses a single monopolar transmitted pulse which radiates through a wide solid angular volume. Echoes caused by objects in this volume are detected by a large diameter, sparse circular array of receiver elements. The time history of each element is stored in a digital memory. A reconstruction processor uses this stored time history to reconstruct an image of the reflecting objects. A simple time of flight algorithm, based on Huygens principle, is used in the reconstruction. The algorithm automatically takes into account transmitted wave front curvature and makes no approximations such as Frensnel or Fraunhofer in the reconstruction. A circular array of receiver elements can be used, which is axicon, and is focused throughout the imaged volume. A perspective processor controls the reconstruction processor such that the volumetric image may be viewed from various perspectives.

Abstract: The errors in phase produced by differences in the locations of taps on a delay line are compensated by determining the error by transmitting oscillations from a test oscillator through each tap and storing the difference between the actual phase and the ideal phase that would result if the taps were perfectly located. When an ideal delay is called for, the tap having the closest actual delay to the ideal delay is selected and the proper phase correction is made.

Abstract: A plurality of ultrasonic transducers or probes are positioned around a region of an object such as a steel tube to be inspected. One of the ultrasonic transducers is energized to emit an ultrasonic beam into the region, and ultrasonic waves reflected from and transmitted through the region in response to the emitted ultrasonic beam are received. Sound pressures are then measured from the reflected and transmitted ultrasonic waves, and an evaluation value is produced by arithmetically dividing the sound pressure of the reflected ultrasonic wave by the sound pressure of the transmitted ultrasonic wave.

Abstract: Ultrasonic sensor and echograph with static sectorial scanning, especially for a wide angle picture, wherein according to a possible embodiment, the sensor comprises several groups of transducer elements forming between one another obtuse angles in such a way as to define overall a convex outline so that the delays or lags necessary to obtain a complete scanning be lower than with a conventional linear strip and thus easier to contol, the sensor being intended to be applied to medical echography.

Abstract: A method and apparatus for three dimensional imaging of a solid angular volume utilizing a single pulse of radiated energy is described. An embodiment is disclosed which utilizes a single monopolar acoustic pulse to insonify a three dimensional volume. An array of transducers is used to collect the echoes which are stored in a memory as a replica of the reflected three dimensional wavefield. This data is processed to form a replica of the three dimensional volume of objects responsible for the echoes which is then stored in a second three dimensional memory. The data in this memory is collapsed in the direction of preferred perspective to enable viewing on a cathode ray tube.

Abstract: There is disclosed an inspection system which allows the visual inspection of an item and the automatic recordation of the position of a defect or other inspection characteristic in the plane of inspection. In the visual inspection of an electronic circuit card, the card is inserted into a holder which maintains the card in a reference plane which is fixed relative to a plurality of sonic emitters. A microscope or other viewing device is fixed in a predetermined position on a support structure and includes cross hairs or other indicia to allow the visual identification of a particular point on an item that is to be visually inspected. A plurality of sonic receivers are coupled in predetermined positions on the support structure to receive sonic energy generated by the emitters.

Abstract: A phased-array ultrasonic transducer for an ultrasonograph is provided in which electrical signals are supplied to ultrasonic transducer elements to generate ultrasonic beams for diagnostic scanning. The ultrasonic transducer comprises a number of ultrasonic transducer elements arranged in the form of an array, a signal electrode plate coupled to the signal-supply side of the transducer elements and connected to a transmitter-receiver circuit by means of signal wires, and an earth electrode plate connected to the earth side of the transducer elements. The earth electrode plate is divided into a plurality of split earth electrode plates corresponding to ultrasonic transducer groups each including a plurality of adjacent transducer elements so that the split earth electrode plates are grounded independently.

Abstract: The invention combines a plurality of ultrasonic ranging transducers (11) arrayed proximate the end (12) of a movable robot arm (13), all transducers (11) being mounted to a common base so as to be pivotally movable both horizontally and vertically relative to the robot arm (13) by stepping motors (17 and 20). By controlling the pivotal movements of the transducer array (10) by a microcomputer (22) so as to look in the direction of intended travel of the robot arm end (13), and as to the robot arm end (13) moves, unexpected objects in the path of the robot (14) or aberrant motion by the robot (14) become easily detected. Upon the sensing of an obstruction to the direction of motion of the robot arm (13), or aberrant motion thereof, a signal from the microcomputer (22) to the robot (14) controls will halt further operation until the obstruction is removed or the problem corrected.

Abstract: In an ultrasonic computed tomography system including an image signal-processing apparatus for reconstructing an image signal of an object on the basis of a synthetic aperture technique, a probe includes a transducer unit. The transducer unit emits an ultrasonic beam to the object and detects the corresponding echo wave. Hologram data is produced in response to the echo wave and then digitized to have a predetermined number of bits by A/D converters. The digital hologram data is temporarily stored in buffer memories and read out under the control of a computer unit. The computer unit has a ROM assembled therein to prestore digital kernel function data, the number of whose bits is smaller than that of the digital hologram signals. The computer unit executes a convolution on the digital hologram data and the kernel function data, thus increasing the speed of a computation needed for image reconstruction.

Abstract: The present invention is a multiline beamformer for use in a medical ultrasound scanner using a phased array transducer. Lines of ultrasound energy are generated having a pressure at the array aperture corresponding to sin (.pi.x)/.pi.x, where x is the normalized distance of the array element measured from the center of the array. This transmitted energy creates a flat field in space which can then be received in multiple receive lines, using bundled, parallel time delays.

Abstract: In the scanning type ultrasonic equipment provided with a probe a plurality of transducer elements and with a phasing circuit for signals which are delivered from the transducer elements on the basis of a received ultrasonic wave, the phasing circuit includes constant current circuits each for converting selected ones of the signals from the transducer elements into a constant current signal, and a delay line having taps which are connected to the constant current circuits, in order to reduce the number of parts included in the phasing circuit and the number of adjusting operations performed therein.

Abstract: An ultrasonic transducer system is disclosed consisting of a support body (2), a radiating layer (8,9), a first .lambda./4 matching layer (10,11) and a second .lambda./4 matching layer (12,13). According to the invention, at least two ultrasonic transducers (4,6) with different and predetermined mid-frequencies are attached to a common support body (2) and have natural foci which overlap if the ultrasonic transducers (4,6) are mechanically separated. The ultrasonic transducer (4), having the higher mid-frequency, is provided with a larger radiating surface (4). This configuration, through the appropriate selection of the mid-frequencies, allows compensation for the frequency dependent damping of the transmission medium by frequency related weighting during radiation. In this manner, substantial improvements with respect to bandwidth of the total transmission path, from transmitting transducer through transmission media to receiving transducer, and the image quality can be realized.

Abstract: The fault-containing area to be inspected is insonified by means of an ultrasonic transducer with a space-limited beam which is displaced in stepwise manner, the signals coming from the successively insonified areas being detected by several receivers, the phases and amplitudes of the signals being determined and the reconstitution of the area to be inspected performed. There is a main image of the fault and also parasitic images thereof. The number of receivers is chosen in such a way that the distance between the parasitic images and the main image exceeds the width of the area insonified by the transmitter and the reconstitution is only carried out in the insonified areas having given rise to a signal in order to eliminate the parasitic images. Application to the non-destructive inspection of mechanical parts.

Abstract: In a method and apparatus for ultrasonic measurement, there are provided first and second ultrasonic transducers arranged to directly oppose each other across an object interposed therebetween, and a third ultrasonic transducer, the transducers being so arranged that a ray from the third ultrasonic transducer intersects, internally of the object, a ray connecting the first and second ultrasonic transducers. A first period of time required for an ultrasonic wave emitted by the first ultrasonic transducer to be received by the second ultrasonic transducer through the object is measured, as well as second and third periods of time respectively required for an ultrasonic wave emitted by the third ultrasonic transducer to be received by the first and second ultrasonic transducers following scattering of the ultrasonic wave from within the object.

Abstract: A multitransducer ultrasonic probe having transducers of different sizes for the nondestructive testing of mechanical parts. The probe has at least one line of M transmitter and/or receiver ultrasonic transducers, a control unit for the activation of at least one group of m juxtaposed transducers, selected from the M transducers and for the displacement of the activated portion of the probe after each activation. The M transducers all have different sizes and are arranged in monotonic manner in accordance with their sizes, the sizes being determined so as to scan an object to be inspected with a redundancy rate which is independent of the depth of the locus to be inspected.

Abstract: An ultrasonic diagnostic probe is provided which performs simultaneous ultrasonic imaging and Doppler flow measurement. The Doppler transducer is mounted for rotation by a mechanical assembly, which permits the Doppler beam to be steered during imaging to the point in the body where a flow measurement is to be taken. As the Doppler transducer is rotated, a variable impedance device within the probe is adjusted in correspondence with the transducer rotation so as to provide an indication signal of the direction in which the Doppler beam is being directed.

Abstract: Continuous wave (CW) Doppler imaging employs a linear array of transducer elements with a first plurality of elements functioning as an ultrasonic wave transmitter and a second plurality of elements functioning as a receiver of the reflected ultrasonic wave. Time delay circuitry connected to the transmitter and receiver elements define the beam focus and beam steering of the ultrasonic wave.

Abstract: An apparatus for reconstructing an image signal of a foreground subject wherein a probe having a plurality of transducers for scanning a foreground subject by radiation, such as an ultrasonic beam, is connected to a phase detector through a receiver. An electrical signal corresponding to a wave reflected from the foreground subject is phase-detected by a phase detector. At least one resultant hologram signal is subjected to the A/D conversion to be stored in a buffer memory. A processing unit causes the hologram signal to be read out of the buffer memory, carries out the convolution integration of the hologram signal and the corresponding kernel function data by the synthetic aperture technique, thereby producing a reconstructed image signal. The processing unit further carries out the nonlinear compression of the amplitude of the hologram signal before the convolution integration and performs the nonlinear expansion of the amplitude of an image signal after the convolution integration.

Abstract: Apparatus for measuring corneal thickness. A transducer is provided that transducer includes a plurality of piezo-electric arcuate segments arranged in a circle to form an annular member. The segments are electrically and acoustically isolated from each other. Leads are connected to each segment for the transmission of electrical signals. The transducer is one component of a system for measuring corneal thickness. Also included in the system are a transmitter which is connected to the leads for applying an electrical signal to the segments to produce respective sound pulses, respective receivers connected to the leads for converting the signals into distance measurements, an averager capable of averaging the distance measurements and a display device to display the average distance.

Abstract: An apparatus for the scanning of objects by means of ultrasound echography, comprising a mosaic (10) of ultrasound transducers which is connected to a transmitter stage (20) and a receiver stage (30) for the reception and processing of the ultrasound echos corresponding to the obstacles encountered by the transmitted signals in their direction of propagation, and also comprising a display stage (40). The transducers of the mosaic (10) are grouped in 2.sup.n subwindows in which a non-corrected echogram of an area of the objects scanned is formed. The receiver stage (30) comprises a device for determining correction delays to be applied to delay devices (61 . . . 68), said device comprising 2.sup.n -1 intercorrelation circuits (101,102, etc.) which operate on the basis of n successive divide-by-two operations of the aperture of the mosaic (10).

Abstract: An annular array ultrasonic transducer is provided which comprises a plurality of concentric rings of piezoelectric material having widths chosen for operation at different depths of focus. The total aperture of the transducer is divided into a plurality of contiguous focal depths. In the near field only the inner element or elements are activated, and rings of increasing radius are added as the depth of focus is increased. The widths of the rings are chosen to keep phase errors across each ring within acceptable limits over the depth of field for which they are energized. The transition depths at which the aperture is changed are chosen to allow rings of manufacturable widths to be employed while maintaining aperture transitions which prevent banding in the ultrasonic image.

Abstract: An ultrasonic diagnostic imaging system is described in which a multi-element transducer array transmits a focused beam of energy from the transducer elements. As the depth of focus is varied between near and far field focusing under operator control, the nominal frequency of the transmitted ultrasound energy is varied correspondingly by the system, from relatively high frequency transmission in the near field to relatively low frequency transmission in the far field.

Abstract: There is disclosed herein a movable, ultrasonic transducer array for use in an ultrasonic inspection system that employs a signal detector and display of the liquid crystal cell type. The movable array uniformly insonifies the object to be inspected and is particularly suitable for inspecting large objects or large areas of an object. The array may include a plurality of sending or emitting transducers which are held in substantially parallel alignment so that their transmission or radiation axes are parallel. The array is part of an assembly which includes a support for holding the transducers and a drive system for moving the array and support along a predetermined path.In a first specific embodiment, the array is mounted on a support which moves along a circular path while maintaining the relative horizontal and vertical positions of the transducers. That movement is accomplished by use of a drive and linkage system which provides for an eccentric-like movement.

Abstract: A method and an apparatus of ultrasonic flaw detection suitable for detecting internal cavern defects of a material, the method involving the mounting on a rotary body of a plural number of skew probes in equidistant positions in the circumferential direction of the rotary body to provide a corresponding number of channels for transmitting and receiving ultrasonic beams in a direction intersecting the axis of rotation of the rotary body at different depths in an inspection zone of a material positioned opposingly to the probes. The rotary body is turned to revolve the probes through 360.degree. about the axis of rotation while transmitting and receiving the ultrasonic pulses. Selected flaw patterns are produced from the peak values of the echoes received at the detection gates of the respective channels in relation with the direction of incidence of the ultrasonic beams.

Abstract: A method and apparatus for ultrasound tomography for use in clinical diagnostics, the apparatus comprising paired couples of transmission transducers (3) and reflection transducers (5,6), the paired couples of transducer means being independently operable within a container (1) of ultrasound transmission medium to provide data capable of processing by computational methods for mathematical reconstruction of the distribution of specific values of acoustic data to permit separate comparative and synergistic examinations of the data thus obtained to classify the internal structure of a body.

Abstract: A method for non-destructive, qualitative testing of properties of materials, whereby ultra-sonic waves are transmitted in the direction of the material. Ultra-sonic waves reflected by the material are received. The orientation of the material relative to the direction in which the ultra-sonic waves are transmitted is changed in a predetermined way, such that the transmitted ultra-sonic waves arrive at the material under varying angles of incidence and from different directions.

Abstract: A receiver device for a multi-element ultrasonic probe echograph comprises for each transducer element (1l to 1N) of the probe (1) a delay line (7l to 7N) controlled by digital time delay circuits (3l to 3N) which supply control signals via digital input-output logics (5l to 5N) controlled by an operating control circuit (2), which transmits signals (Sl to SN) to the delay circuits (3l, 3N) by a single clock (6) and by a single input-output control circuit (4).