Abstract: A PASS ultrasonic system performs a scan in which phase errors due to aberrations in the sound media are corrected prior to the acquisition of each beam. Phase errors are measured by cross correlating each of a set of reference beams with the desired beam to produce beam forming errors as a function of beam angle. This function is Fourier transformed to produce phase corrections that are employed by the ultrasonic system to offset the phase errors.

Abstract: An apparatus that allows the three-dimensional reconstruction of anatomic structures through the acquisition of two-dimensional echographic images produced by the real-time processing of signals reflected and/or scattered by said structures when these are hit by a beam of ultrasound generated, according to a predetermined scanning plane, by a piezoelectric transducer contained within an echographic probe. According to the invention, the scanning plane, in which the sector-scan transducer emits the beam of ultrasound, rotates through an angle of 180.degree., with intermediate angular increments having a predetermined amplitude and frequency, around the longitudinal axis of the probe, while the latter remains fixed relative to the examined anatomic structure, there being provided means for the actuation and the control of the rotation of the scanning plane.

Abstract: A delay circuit of ultrasonic diagnostic apparatus comprising a delay line consisting of a plurality of unit portions connected in cascade, in each of which an anode of a first variable capacitance diode and a cathode of a second variable capacitance diode are connected with a connecting point of two inductors connected in series, or a delay line obtained by replacing capacitances in a second order all pass type delay line by variable capacitance diodes, or a delay line, in which variable capacitance diodes and inductors form a balanced circuit; and control circuit for applying a reverse bias voltage to each of the variable capacitance diodes; and an amplifier or a variable resistance circuit using FETs serving as a matching circuit for the delay line, capable of varying continuously an input impedance by using a control voltage from the exterior.

Abstract: An ultrasonographic apparatus for diagnosis which produces a sectional image of an object by a shifting focus system or a variable aperture system from echoes which are obtained from ultrasonic waves radiated to the object. The echoes from the object are transformed into echo signals based on their intensity (100, 102). The echo signals are individually delayed by different periods of time to form signals associated with different depths of the object (110, 112). Among the delayed echo signals, those associated with a particular depth are combined (108, 113A, 113B, 114A, 114B, 116A, 116B, 118A, 118B, 120, 122A, 122B, 124) with the result that a sectional echo image of the object is displayed (126, 128, 130).

Abstract: In an ultrasound diagnosis apparatus, a focusing point of received ultrasound beams is moved along a transmission direction of the ultrasound beams so as to receive echo signals at all the focusing points on a scan line by one transmission operation. Reception opening portions of an ultrasound probe are changed to receive and add the echo signals in a plurality of directions at the respective focusing points, thereby reducing a speckle noise.

Abstract: An ultrasound apparatus has a first group of transmission and reception channels that are respectively allocated to elementary transducer in the active aperture of a connectable transducer array. The central transmission location generated by a transmission channel and the reception location sampled by a reception channel coincide and lie on the allocated elementary transducer. In addition, a second group of transmission and/or reception channels is present, each being respectively simultaneously connectable to a plurality of elementary transducers via transmission and/or reception transfer stages for generating a virtual transmission and/or reception location that lies between the elementary transducers.

Abstract: In order to measure a layer in the volume of a reflective structure, a transducer matrix emits at least one sonic or ultrasonic wave packet which coherently impinges on the layer. The echo signals at each element of the transducer matrix are processed separately, on the basis of determined distances between transducer elements and volume elements, and signals corresponding to the echo of each volume element on all the transducer elements of the matrix are calculated by correlation. By emitting two or more wave packets and evaluating the resulting phase or frequency difference therebetween, a two-dimensional velocity field of the structure in the layer can also be determined.

Abstract: The present invention is directed to an ultrasonic flaw detector for inspecting the surface condition of a specimen or the existence or non-existence of one or more internal defects in the specimen by scanning the specimen with ultrasonic waves and analyzing waves reflected by the specimen. The ultrasonic flaw detector includes a number of array elements arranged in a line. The ultrasonic beam scanning of a specimen is performed by vibrating plural ones of the array elements to form a single ultrasonic beam and shifting vibration of the array elements one by one. Array elements are divided into plural blocks by a block selector. Ultrasonic scanning is simultaneously conducted in the respective blocks.

Abstract: An ultrasound system steps focus and power through a series of focal zones to provide real-time seamless images with a range exceeding the depth of field of the employed ultrasound transducer. The information required for the focus and power functions are stored in memories which are read out by a zone sequencer. The data is stored in registers in the drive circuitry so that no time is lost in generating succeeding power bursts. Echoes are received from successive zones at a given steering position rather than at successive steering positions of a given zone. Provision is also made for adapting time-varying gain functions applied at a receiver as a function of zone to optimize contrast uniformity and minimize contrast discontinuities. The zone sequencer controls the input of processed echo signals into a video buffer, gating out unwanted information and splicing echo signal segments from successive zones into continuous sector lines for display on a monitor.

Abstract: An apparatus for electrically blending echoes from a plurality of focused beams into a composite image having reduced image artifacts. The apparatus comprises a transducer generating a sequence of beams having different focal points and converting resultant echoes into electrical signals, a receiver with its gain adjusted according to (1) time and (2) the transmitted beam, a multiplier that develops the product of the receiver output and a gain selected both by the transmitted beam and (time), and a summing network that adds together outputs of the multiplier that originated from the same sound scatterer.

Abstract: A method for dynamic focus of received energy, in a vibratory energy imaging system, into a beam in which contribution from transducers in an array of N such transducers, are progressively enabled to contribute to beam focussing dependent upon distance between a particular j-th transducer (where 1.ltoreq.j.ltoreq.N) is responsive to the depth, or range R, of the focal point at any instant of time; the initial steering angle .theta., with respect to the array normal, is used in conjunction with a range clock, to determine the time when each off-normal transducer channel is enabled to add to the beam (dynamic apodization) and to finely adjust the channel time delay to properly focus the beam after the enablement of the channel.

Abstract: A method of transforming a multi-beam ultrasonic image in which a plurality of ultrasonic beams are simultaneously transmitted into an object along a plurality of lines and across a plurality of arcs. The reflected signals are sensed along each line and sampled thereby creating an image matrix of sampled values taken from the intersection of each line and arc. For each image value, a linear combination of surrounding values is formed to create a transformed image value which reduces the effect of interbeam interference.

Abstract: An ultrasonic measuring system including a transducer having a plurality of row electrodes on one surface thereof and a plurality of column electrodes crossing the plurality of row electrodes on the other surface thereof and made of an electrostrictive material in which piezoelectricity is induced by a bias electric field applied thereto to thereby obtain sectional images sequentially. A row position selector is connected to the row electrodes to select several row electrodes and apply a direct current bias voltage to the selected electrode and to shift the position of the selection sequentially. An electronic B-mode image scanner is connected to the column electrodes to shift the directivity of the transmission/reception ultrasound beams sequentially widthwise of the column electrodes (in the direction of row extension) to obtain echo signals indicative of an acoustic reflective response.

Abstract: An ultrasonic diagnostic apparatus includes a transmit/receive circuit having a plurality of transmit channels for enabling a drive pulse to a corresponding ultrasonic oscillation element and a plurality of receive channels for receiving an ultrasonic signal echoed back from a subject and an ultrasonic probe having a plurality of ultrasonic oscillation elements smaller in number than the number of channels in the transmit/receive circuit. The apparatus further includes a connector for selectively connecting a plurality of transmit channel output terminals in a parallel connection unit to a corresponding ultrasonic oscillation element to drive ultrasonic oscillation elements in parallel fashion or a plurality of receive channel input terminals in parallel connection unit to a corresponding ultrasonic oscillation element in the ultrasonic probe to receive an echo signal via the corresponding plurality of receive channels for processing.

Abstract: The present invention for realizing an ultrasonic diagnosis apparatus for displaying a high-quality image having a smaller amount of speckle noise is characterized in that receiving signals of a plurality of sound rays each having a different directionality within a range of bearing resolution of an ultrasonic beam are subjected to correlation processing to determine a receiving signal for the portion of one sound ray, and an image is formed on the basis of receiving signals thus determined, thereby eliminating speckle noise. Correlation processing in its simplest form may be addition averaging processing.

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 fresnel 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: Ultrasound imaging apparatus has a probe disposed on a longitudinal axis. A linear array of ultrasound transducer elements is arranged along the axis of the probe. The array is alternatively held stationary and oscillated relative to the probe about the axis between limits to define a sector. In a first mode, the transducer elements are actuated successively while the array is held stationary to generate a longitudinal rectilinear scan. In a second mode, some of the transducer elements are actuated repeatedly while the array is oscillated to generate a transverse sector scan orthogonal to the longitudinal scan. The echoes received by the transducer elements in the first and second modes are displayed as images of respective orthogonal planes. In either case, the user selects the position of the scan plane within the field of view of the array while the probe is held in a stationary position against the skin of the patient.

Abstract: A beam former method and an apparatus therefor in an ultrasonic imaging system, in which switching of delay elements is performed by means of delay switches in a section in which no ultrasonic wave transmission/reception is performed and switching noise generated in this section is stored as a noise signal into a memory. The stored noise signal is subtracted from a reception signal which is obtained through ultrasonic wave transmission/reception and which contains switching noise superimposed thereon to thereby obtain a reception signal from which the noise has been eliminated.

Abstract: An ultrasonic diagnostic apparatus which has a probe including a plurality of transducer elements made of an electrostrictive material arranged on a plane in two-dimensional directions, a bias applying unit for selecting the transducer elements in an arbitrary row in the horizontal direction to be in an operative condition by applying the same with a bias voltage, and a switching unit for selecting the transducer elements in at least one arbitrary column in the vertical direction by applying the same with a bias voltage, and controls the bias voltage applying unit and the switching unit to scan an ultrasonic beam in the two-dimensional directions to collect three-dimensional information on a body under inspection.

Abstract: An ultrasonic echographic imaging device for two dimensions (x, y), includes an adaptive filter for reducing the interference noise in the images obtained. A first circuit differentiates the signal (E(x, y)) applied to the adaptive filter and a second circuit forms the weighted sum of the signal (S(x, y)) leaving the adaptive filter (200) and the signal (dE(x, y)/dy) output of the differentiating circuit.

Abstract: A device for the three-dimensional focusing of an ultrasonic beam, comprising:a phased array (100) has a cylindrical shape with a generatrix X'X, and which comprises M.times.N elementary transducers which are arranged in a curved matrix consisting off M rows extending parallel to X'X and N curved columns extending perpendicularly to said rows.A circuit (200) forms focusing planes P.sub.j which extend through X'X, which circuit is formed by:a multiplexer (201) which selects, for each column i, from the M.times.N signals received by the array (100), the m.sub.o signals S.sub.jk.sup.I supplied by the elementary transducers whose row number is j+k, where K=0, 1, . . . , m.sub.o -1, where m.sub.o is a given number respresenting the aperture width of the ultrasonic beam, and which also forms the sum S.sub.jk.sup.i of the signals S.sub.jk.sup.i and S.sub.jk.sup.i, m.sub.

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 fresnel 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: A curved acoustic probe provided with a plurality of electroacoustic transducers delivers a beam of acoustic energy which is directed by electronic scanning. Electronic scanning is carried out by utilizing only those electroacoustic transducers which are capable of insonating the target. It is thus possible to employ a large number of electroacoustic transducers in respect of each azimuth and therefore to obtain high definition. The invention applies to imaging techniques involving the use of acoustic waves such as ultrasonic waves and is primarily concerned with the field of ultrasonic medical imaging. Chief among potential applications are nondestructive testing, production of images within liquids such as, for example, underwater or ocean-bottom images.

Abstract: Antenna, in particular for a sonar, allowing to form directional channels by feeding the transducers by a reduced number of sources by means of an interpolation network that permits to maintain to a low level the image lobes in spite of this reduction of the number of sources.

Abstract: A method for imaging a sample with a beam of vibratory energy from an array of transducers excites the array with successive ones of a plurality M of coded excitation signal sets with each set occurring in a different one of successive excitation time intervals. Each different set has signals with a different code. An excitation beam, produced by the array, is focused into the sample at successively smaller distances, along a selected ray path from the array, during each successive excitation time interval. A reception beam is focused along the ray path at successively greater distances from a minimum distance away from the array during each successive one of a like plurality of reception time intervals, for receiving, during each reception time interval, return response signals reflected from the sample.

Abstract: A method and apparatus for improved digital processing of the analog echo signals in a coherent imaging system is described which simplifies the channel circuitry requirements. The analog echo signals detected with a phased array of transducer elements are first compressed in a non-linear manner then expanded non-linearly with analog-to-digital converter means to provide increased instantaneous dynamic range in the overall system. Representative phased array coherent imaging systems having the improved digital processing means are also disclosed.

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 fresnel 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: A detection system forms a plurality of reception beams successively in angular directions by receiving incoming signals from various directions in a manner that the Doppler effect is produced to vary the carrier frequency of the incoming signals. The detection system displays underwater conditions on an indicator. To determine the underwater conditions, the detection system uses a plurality of ultrasonic transducers for receiving incoming signals, a plurality of preamplifiers for amplifying the reception signals produced by the ultrasonic transducers. A first coupling device which connects at least two of the ultrasonic transducers to a single preamplifier, and a matched filter for pulse-compressing reception signals produced by the ultrasonic transducers. A second coupling device successively couples the output terminals of the preamplifiers to an input terminal of the matched filter. The indicator displays output signals from the matched filter.

Abstract: In an ultrasonodiagnostic tomography apparatus for transmitting focused sound wave from a plurality of transducers forming an array to a predetermined focus point and for carrying out beam formation for receiving sound from said focus point with dynamic focusing, wherein the width of transmission beam at said focus point is controlled by means of said transducers so that the width of transmission beam at said focus point may be larger than the width of receiving beam from said focus point.

Abstract: An ultrasound system for investigating a subject comprises a probe, a signal processing module, and an interconnecting cable. The probe includes an annular phased array transducer defining multiple signal processing channels. The signal processing module includes a controller, a transmitter, a receiver, delay circuitry, and a video section. Within the delay circuitry, each signal processing channel includes an inphase branch and a quadrature branch. Each branch includes an analog-to digital converter (ADC) and a delay first-in-first-out (FIFO) memory. Dynamically variable delays are implemented by varying the sampling and FIFO input rates relative to constant FIFO output rates. The variable clock rates are derived by switching between phase-staggered replicas of a master clock MCLK, which has a rate at the nominal center frequency of the ultrasound signal prior to sampling.

Abstract: In an ultrasonic imaging apparatus utilizing an array type ultrasonic probe having a number of arrayed probe elements, high frequency pulse signals subject to different delays are supplied to respective probe elements so as to generate an acoustic beam which converges to a predetermined focal point. When receiving a reflection acoustic beam resulting from the converging beam, a plurality of signal lines extending from respective probe elements are connected in common to set up a plurality of element groups each having a plurality of adjacently arrayed elements and respective signals derived from respective element groups are differently delayed and added together to generate a reception signal representative of a reception beam having a predetermined focal point.

Abstract: An ultrasonic imaging apparatus comprising an ultrasonic transducer, and a delay circuit section. The transducer has an array of ultrasonic transducer elements, and emits ultrasonic waves and receives echo waves to convert these waves into echo signals. The delay circuit section delays the echo signals by delay times determined by at least the directions in which the ultrasonic waves have been emitted from the transducer. This circuit has first and second memories for alternately writing and reading the echo signals, and a circuit for addressing the first and second memories by applying these memories with addresses, the number of which corresponds to the delay time.

Abstract: Apparatus for calculating the delay coefficients to be used for the transducer of a linear array at successive focal points along each radial line of a sector along which ultrasonic pulses are transmitted comprising a plurality of clocked accumulators connected in series, the accumulators being preloaded with appropriate combination of the coefficients of the successive terms of a series expressing an approximation of the formula, D=R-.sqroot.(X-Xo).sup.2 +Yo.sup.2 where R is the distance of a focal point from a given point in the sector, X is the number of the accumulator from the origin and Xo, Yo are the coordinates of the focal point.

Abstract: An ultrasonic diagnosis apparatus comprises a probe for transmitting an ultrasonic beam onto a target body and receiving an ultrasonic echo from the target body and a diagnosis device for supplying a transmission pulse to the probe and processing an electrical signal from the probe to prepare tomographic image information.

Abstract: To reduce the power consumption of the ultrasonic probe, the number of transducers to be driven at any given time is controlled. More specifically, all transducers are driven, whereby the probe transmits the ultrasonic beams to a subject through an acoustic lens provided in front of the probe. When an echo signal reflected from an interior portion of the subject and a multi-echo signal reflected from the acoustic lens are detected, the transducers whose operation is required to obtain a tomographic image of the subject are driven. When only the multi-echo signal is detected, fewer transducers are driven.

Abstract: A liquid crystal display device utilizing an insulating substrate, a plurality of transparent electrodes disposed on the insulating substrate in a matrix fashion to form a plurality of pixels, and at least two thin film transistors disposed in the vicinity of each of the transparent electrodes on the insulating substrate, each the thin film transistor having a drain electrode, a source electrode and a gate electrode. The drain electrode is connected to the transparent electrode, a gate electrode line for each line or column of the transparent electrodes is disposed on the insulating substrate in the vicinity thereof and each gate electrode of the thin film transistors connected to each of the transparent electrodes of the line or column are connected in common thereto. The source electrode lines for each column or line of the transparent electrodes are disposed on the insulating substrate in the vicinity thereof and at a right angle to the gate electrode line.

Abstract: This invention provides an ultrasonic transducer system which utilizes a reconfigurable delay line to perform a variety of processing functions. In particular, for a preferred embodiment, the delay line utilized to sum the outputs of transducer elements is reconfigurable to provide serial processing of image scan lines while providing parallel processing of Doppler color flow scan lines. More particularly, the echo signals generated in response to the packet of color flow lines utilized to generate color flow information are applied in a predetermined way to two separate portions of the delay line, the portions of the delay line having different delay profiles, the resulting outputs being focussed to slightly different points in the image and thus providing color flow packets for two separate points in response to the transmission of a single packet of color flow lines. This results in a substantial enhancement of the system frame rate.

Abstract: Delay time data for using the transducers arranged within a probe, for transmitting and receiving an ultrasonic beam, is stored in a memory. The amount of this delay time data is less than that required for using all transducers. The delay time data stored in the memory is interpolation-processed, thereby providing additional delay time data. The sum of the delay time data stored in the memory and the additional delay time data obtained by the interpolation-processing suffices to use all the transducers incorporated in the probe.

Abstract: An ultrasonic echography apparatus which comprises a first processing circuit (100) of a known type for the processing of the ultrasonic echos in order to display an A-type echogram on a display device (103), and a second processing circuit (200) which is connected parallel to the first processing circuit and which consists mainly of an amplifier (210), a group of n parallel connected channels (220a . . . 220n) each of which comprises at least one band-pass filter (221a . . . 221n) and one envelope detector (222a . . .

Abstract: An ultrasonic flaw detector comprises channels for transmitting and receiving electrical signals. The transmission channel comprises a sync pulse generator (1) connected to a sonic pulse generator (2) and transmitting piezoelectric elements (3). The receiving channel comprises receiving piezoelectric elements (4), a radio-frequency pulse amplifier (6), a video detector (7), a control voltage generator (15), and horizontal-sweep and vertical-sweep generators (16 and 15) which are connected to a frequency divider (13). The output of the video amplifier (8) is connected to a multivibrator (10). The receiving channel also comprises three electronic switches (11, 12, and 5).

Abstract: An apodization attenuation circuit to achieve a selected percent Gaussian apodization of a focused ultrasound wavefront when transmitted from a linear or phased array. The circuit uses a string of resistors, one resistor positioned between the drivers of each element in the transducer array. Each node of the resistor string functions as the reference potential input for one driver. Each node includes a pair of normally open switches, one of which may be closed to common and one of which may be closed to full reference potential. By closing four switches, two to common and two to full reference potential, a profile of potential of a selected percent Gaussian apodization can be achieved such that the output pulse magnitude of each transducer element in an aperture varies as a Gaussian function of its distance from the center of the aperture.

Abstract: A method for phase conjugation adaptive reduction of phase aberration effects upon the time delays necessary for information of a beam of coherent energy focused within non-homogeneous medium at a selected range R from, and at an angle .theta. with respect to the normal to, the surface of an array of a plurality N of transducers, each for providing a portion of the energy of the beam when excited and for converting energy reflected thereto to a signal therefrom, first bounces from a large collection of scatterers, contained in a portion of the medium to be investigated, a probe beam for that beam angle .theta.; cross-correlating, for each probe beam, the received signals from each of the (N-1) pairs of adjacent transducers to derive a like number of phase conjugation correction signals; arithmetically operates upon the plurality of phase conjugation correction signals to provide a time correction for the time delay associated with each probe beam transducer, for that range R and angle .theta.

Abstract: An apparatus for transmitting and receiving ultrasonic signals for an ultrasonic imaging device operating by the pulse echo method. There is arranged next to a linear array of ultrasonic transducer elements serving as ultrasonic transmitter, a matrix type array of ultrasonic transducer elements serving as ultrasonic receiver, the columns of which run parallel to the longitudinal direction of the linear array. By the use of the matrix type array of ultrasonic receivers it is possible to receive echo signals from a wide angle range and to discriminate them with respect to their scattering angle.

Abstract: A method for ultrasonically detecting flaws in a welded portion of a pipe by using an ultrasonic wave phased array probe having an array of a plurality of transducer elements for emitting and receiving ultrasonic wave beams, wherein at least one monitoring probe is located in the vicinity of the welded portion to receive the ultrasonic wave beam, whereby peak values of the ultrasonic wave beams are detected within a predetermined gate, a maximum peak value of the detected peak values is determined to determine a pilot beam having the maximum peak value, and effective beams which reach the portion of the welding portion to be tested are determined from the determined pilot beam.

Abstract: A three-dimensional imaging system for obtaining a three-dimensional image of an object being scanned ultrasonically comprises a source arrangement for sequentially transmitting ultrasonic energy toward the object in successive directions in a first scanning plane, followed by sequential transmission of ultrasonic energy toward the object in successive directions in successive scanning planes parallel to the first scanning plane, a detector arrangement for receiving reflected energy and converting the reflected energy to electrical signals, and a processor for processing the electrical signals to develop reconstructed image data of the object, the reconstructed image data comprising forward projections of the object into a left image plane and a right image plane to form left and right images, respectively, the left and right images forming a stereo pair for composite display by a display unit.

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 transmitter/receiver for suppling a pulse power to a transducer and receiving a signal from the transducer comprises a parallel connection of a first circuit including a first switch element connected in series with a power supply having one terminal thereof connected to a common potential point, a second circuit including a second switch element connected in series with a receiver having one end thereof connected to the common potential point, and a third circuit including the transducer having one end thereof connected to the common potential point.

Abstract: An ultrasonic imaging apparatus is constituted by an ultrasonic transducer for scanning an object to be examined with an ultrasonic beam in a plurality of scan directions and converting echo waves from the object into echo signals, a transmitter for driving the ultrasonic transducer twice, so as to cause the ultrasonic transducer to emit the ultrasonic beam twice in each scan direction, a delay circuit for causing the echo signals to be subjected to signal-processing by different delay amounts to alternately form odd- and even-numbered receiving focus regions in the scan direction upon two transmission operations of the ultrasonic beam and for outputting echo signal components corresponding to the odd- and even-numbered receiving focus regions, and a mixing circuit for mixing the echo signal components corresponding to the odd- and even-numbered receiving focus regions to form video data for one scan line.

Abstract: An ultrasonic imaging apparatus and method of forming an image of an acoustic image of an object employing the aperture synthesis technique, in which at least one partial aperture for accommodating a predetermined number of successive transducers is established and applied to a transducer array to select the predetermined number of successive transducers accommodated in the partial aperture so that the selected transducers serve to transmit ultrasonic acoustic signals to an object and receive signals reflected from the object, and the at least one partial aperture is specifically moved along the arrayed transducers for similar signal transmission to and/or signal reception from the object, whereby the apparatus and the method do not suffer substantial noise caused during changeover between transmitting and receiving operation modes and/or enjoy and enlarged aperture for signal transmission or enlarged aperture for signal reception with a suppressed decrease of the frame rate.

Abstract: A pulse compression apparatus comprises a quadrature detector for converting an echo signal obtained by an ultrasonic transducer into a complex signal, a reference wave oscillator for producing a reference wave signal, and a correlation circuit for deriving a correlation between the complex signal and the reference wave signal to compress the echo signal.