Abstract: A transducer array and excitation circuitry for producing ultrasonic waves in a controlled pattern and for causing the waves to be scanned along the array. The array comprises a plurality of transducer elements coupled to each other in such a way as to produce a desired wave pattern when selected elements are activated. The array may be constructed from plural transducer elements or from a single plate of transducer material comprising a plurality of elements that can be individually activated, the plural elements being intercoupled to produce the desired wave pattern. The arrangement is such that a minimum number of electrical connections to the transducer elements are required to create the desired wave pattern and to scan that pattern across the face of the array.

Abstract: The disclosed apparatus of the invention operates to generate and direct ultrasound over predetermined regions of a body, such as a programmed sequence of target points. A plurality of side-by-side tapered piezoelectric transducer elements are provided. Means are provided for energizing the transducer elements with electrical energy having a variable frequency. The frequency of the electrical energy is varied to change the direction of the ultrasound produced by the transducer elements. In the preferred embodiment of the invention, a processor is responsive to a coordinate of an input target point for controlling the variation of frequency. In one form of the invention, means are provided for varying the relative phases of the electrical energy applied to the transducer elements. In this form of the invention, the processor means is also responsive to at least another coordinate of the input target point for controlling the variation of the relative phases.

Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse. Always only one group of the transducer elements on the linear array is active and is connected via transmit switches to the transmitting system, and via receiver switches in series with a wiring arrangement to the receiving system. This facilitates the implementation of an ultrasonic imaging system for high ultrasonic frequencies, particularly in the order of at least 30 MHz, in which the use of a switching matrix in the radiation and receiving system is avoided.

Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse, and the echo signals of the transducer elements of the beam aperture are added and phase delayed by the software. In this manner, an ultrasonic imaging system for high ultrasonic frequencies, particularly at least in the order of 30 MHz is achieved in which transmitting and receiving lens can be created independently of one another in the computer by changing the software, while the hardware remains unchanged.

Abstract: Electronically changing the effective element spacing of an array of acoustic transducer elements between the transmit and receive modes of operation of an ultrasound apparatus results in reducing the deleterious effects of grating lobes present in the pattern of the array because of element spacings in excess of one half of a wavelength. A linear or quadratic time delay distribution, or both simultaneously, is applied to the array for scanning and/or focusing by setting individually the time delay of the energy associated with each element of the array during one mode of operation, e.g. transmit. The array is organized into groups of elements, e.g. pairs, and the time delay distribution is applied by setting the time delay of the energy associated with each group of the array during the remaining mode of operation, e.g. receive.

Abstract: In an ultrasonic diagnostic apparatus using an array type transducer probe, wherein improved tomographic image resolution is desired by electronically focusing ultrasonic wave toward an object to be examined in both directions, i.e., the array direction and the lens direction. During first scanning of the ultrasonic transducer array in the array direction, the signals received from the probe are synthesized in phase with respect to each other via delay lines having predetermined delay times to obtain first scanned signals in real time, so that focusing the reflected ultrasonic wave can be electronically accomplished in the array direction. After this first scanning, the probe is mechanically moved to a given position in the lens direction normal to the array direction. Then a second scanning operation is accomplished to obtain similar first scanned signals. All of the first scanned signals are processed by a delay time control circuit, digitized, and then stored.

Abstract: The invention involves an ultrasonic tomography device having an ultrasonic transmitting and receiving system for scanning an object under examination from different angles line by line, a fluid tank for immersing the object to be examined, a cover for the fluid tank with a round opening in the center for inserting the object under examination, and a support for an ultrasonic transmitting and receiving system which rotates in the fluid tank around an essentially vertical axis aligned toward the round opening in the center of the cover. In the case of such ultrasonic tomography devices, there is both the requirement of obtaining information from areas as close to the chest wall as possible, and the necessity of distinguishing localized information that can be traced back to artifacts, from real localized information.

Abstract: Ultrasonic imaging apparatus including ultrasonic transducers for emitting acoustic wave beams of various apertures, apparatus for directing two acoustic wave beams of substantially different focussing distances on the same beam direction, circuitry for receiving the reflected waves corresponding to the beam directions, apparatus for modulating the scanning lines corresponding to the beam directions of the reflected acoustic waves, and apparatus for composing the scanning lines corresponding to the two acoustic beams directed on the same beam direction into a single scanning line for display.

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: Ultrasonic wave attenuation in passing through tissue is determined from frequency changes in reflected ultrasonic waves passing through the tissue. In a baseband ultrasonic imaging system in which transducer generated signals are coherently detected by mixing the signals with a fixed frequency signal both in phase and in phase quadrature, a measure of frequency change in the reflected ultrasonic signal is obtained by measuring phase shift in a side band of the mixed signals.

Abstract: A phased-array receiver used in an ultrasonic diagnostic apparatus or the like for appropriately varying the phases of the output voltages from transducer elements receiving ultrasonic waves and for summing these voltages to change the directional or other characteristics of ultrasonic waves. The receiver is equipped with a plurality of blocks each comprising a tapped delay line and a crosspoint switch. The crosspoint switch is capable of selecting any desired one of various delay periods of the delay line. The receiver can perform all types of scans ranging from linear scan, intermediate scan, dynamic focusing scan, to sector scan.

Abstract: A first array (A) of ultrasonic transducers transmits ultrasonic shear waves circumferentially around an examined cylindrical object (110). A second array (B) transmits ultrasonic shear waves axially along the examined object. Triggering pulses from a triggering amplifier (22) are switched by a multiplexer (24) to each individual transducer of the first and second arrays. As one of the transducers assumes the role of a transmitting transducer and transmits an ultrasonic wave, the other transducers of the first and second arrays assume a receiving mode to receive reflected ultrasonic components. A wave travel timer (26) measures the duration for an ultrasonic wave to be transmitted from the transmitting transducer to a defect and for a reflected component to propagate from the defect to the receiving transducer.

Abstract: An ultrasonic transducer in which a plurality of elements are employed alternate ones of which are utilized as transmitters and receivers and having the same area but in which the transmitter elements are composed of material having a high transmit sensitivity while the receiver elements are composed of a material having a high receive sensitivity.

Abstract: Ultrasonic diagnosis apparatus including a plurality of transducer elements in a probe actuated by electric pulses for emitting ultrasonic pulses, for receiving echo ultrasonic pulses, and for issuing electric pulses corresponding to the echo pulses; a pulse generator; apparatus for processing the electric pulse information issued by the probe; a photo transmission line interconnecting the pulse generator and the probe and interconnecting the probe and the processing apparatus; and devices for converting electric pulses to photo pulses for conveyance on the photo transmission line and devices for reconverting the photo pulses to electric pulses after conveyance on the photo transmission lines are utilized with M number of multiplexers. Each multiplexer has L number of taps to drive N number of transducer elements where N=M.times.L.

Abstract: The device, particularly useful for B echographic examination of an organ or of an internal anatomical structure, comprises a line array of N identical transducer elements (12.sub.i, . . . , 12.sub.N) distributed at equal intervals and operating at a predetermined frequency f, means for storing at least one distribution of delays of n successive transducers (n being less than N) corresponding to focussing at a predetermined distance from the line for frequency f, switch means enabling a group of n transducers to be connected temporarily to signal emitting or receiving means with delays corresponding to the distribution and the group of n transducers to be shifted so as to effect scanning.

Abstract: An ultrasonic microscope displays an ultrasonic wave image of a sample relatively and two-dimensionally scanned with respect to an ultrasonic wave beam transmitted from and focused by a transducer including a piezoelectric element and an acoustic lens. The F number of the acoustic lens is variably changeable while the scan in one direction of the two-dimensional scan is substituted by a time axis scan of the received echo.

Abstract: An ultrasound visualization system, and certain aspects of the electronics that are incorporated therein. A scan conversion system which includes means for converting the ultrasound scan signal into a stream of single bit digital data in which each bit is indicative of the relative amplitude of the ultrasound scan signal as compared to the amplitude indicated by previously converted digital data. The single bit digital data is inputted and stored alternately into two full screen buffers. As the data is read into one of the two full screen buffers, the stored data in the other buffer is being simultaneously converted into an analog television video signal. The digital to analog conversion is accomplished by varying an analog television video signal in response to the relative amplitude indicated by each bit in comparison with the amplitude indicated by previously converted digital data.

Abstract: A simple, versatile switching system for ultrasonic transducer arrays uses in-probe concentration and a crosspoint switching matrix, both under the control of a microprocessor in the control unit. The number of crosspoints is kept to a minimum by connecting transducer elements to the pulse delay or receive delay lines in symmetrical pairs; and the high-voltage pulsing is done on the probe side of the switching matrix to allow the use of the same light-duty matrix for both pulsing and receiving.

Abstract: An ultrasound visualization system, and certain aspects of the electronics that are incorporated therein. A scan conversion system which includes means for converting the ultrasound scan signal into a stream of single bit digital data in which each bit is indicative of the relative amplitude of the ultrasound scan signal as compared to the amplitude indicated by previously converted digital data. The single bit digital data is inputted and stored alternately into two full screen buffers. As the data is read into one of the two full screen buffers, the stored data in the other buffer is being simultaneously converted into an analog television video signal. The digital to analog conversion is accomplished by varying an analog television video signal in response to the relative amplitude indicated by each bit in comparison with the amplitude indicated by previously converted digital data.

Abstract: An electronic scan type ultrasonic diagnosis apparatus for forming a tomographic image of a patient body is disclosed. In order to focus ultrasonic waves emitted from a probe having an array of electroacoustic oscillators, driving pulses are delayed by a surface wave delay device. The delay device has a surface wave propagating medium, a first transducer including a main surface wave electrode and two sub surface wave electrodes, and a second transducer including an array of surface wave electrodes. The main and sub electrodes of the first transducer are arranged along an arc having a center situating at a middle point of the electrode array of the second transducer and the surface wave electrodes of the second transducer are arranged along an arc having a center situating on a center line connecting the main electrode and the middle point of the second transducer and a radius which is a half of that of the arc along which the main and sub electrodes are arranged.

Abstract: An ultrasound imaging system particularly adapted for detecting structure which reflects ultrasound at a variety of angles. There is a plurality of ultrasound transducers, which may be a linear array or a two-dimension array with the various horizontal rows of the array offset from one another, but having zero horizontal space or overlapping between adjacent vertical transducers. A sequencer causes one transducer to fire and then listen for an echo; if no echo is heard, the same transducer fires again and an adjacent transducer listens; if there is still no echo, the transducer fires and the next adjacent transducer listens; and so on until a predetermined listening sequence is concluded.

Abstract: An ultrasonic system for non-destructive testing in industry and for visualizing soft tissue structure in medical diagnosis using a coaxial transducer array formed of a plurality of annular transducer elements each having the same predetermined area. The area of each of the transducer elements and the radiating aperture of the array is chosen to provide a well-resolved narrow beam in accordance with the focal length along the axis of the array.

Abstract: A variable delay memory system (200) has an addressable memory means (66-1) having a data input port and a data output port. A counter (206) is connected to supply a write address on bus (212) for storage of data supplied to the data input port on bus (64-1). A subtracter means (214) is connected to receive the write address as one input on bus (210) and a second input proportional to a desired delay time on bus (72-1). The subtracter means (214) is connected to supply its output as a read address on bus (216) for data stored in the memory means (66-1) to be supplied at the data output port on bus (76-1).

Abstract: An ultrasonic synthetic aperture testing apparatus comprises transmitting/receiving sections having an ultrasonic wave probe for transmitting and receiving ultrasonic waves at multiple points on the surface of a steel material, an operation section for accumulating the received signals corresponding to the distance between the multiple points and a reproduction point in a desired region of the material under testing, and a display section for displaying an image formed as a result of this accumulation operation. The ultrasonic wave probe is provided with vibrators corresponding to the respective vibration modes so that two kinds of ultrasonic waves in different vibration modes may be transmitted and received. The accumulation section is provided with a mechanism which performs accumulation and arithmetic operation for the two kinds of waves in different modes.

Abstract: The device comprises n spaced transducers associated with a generator through phase-shift means. These means are formed by members (66) for supplying, on different channels and from the same pulse of the generator, pulses with different time delays. Amplifiers are each associated with a transducer and are controlled from the pulse appearing on the appropriate channel selected by storage means. A receiver (62) associated with the transducers (12) comprises a single delay line with multiple taps closed upstream across a matched impedance and forming phase-shift means at reception.

Abstract: An ultrasound tomography device for scanning an object under examination from a plurality of directions. Coronal slice images of the plane areas near or at the female breast wall are obtained. Ultrasound lobes from ultrasound transducers are electronically directed or mechanically positioned to obliquely strike the coronal slice located at or near the breast wall. A full image of the coronal slice plane is reconstructed through section by section combination of the images obtained from the several ultrasound lobes.

Abstract: An ultrasound diagnosis apparatus comprising, a pulser, a transducer connected to the pulser, which is driven by drive pulses from the pulser to radiate ultrasound wave toward an object and to receive echoes returned from the object to convert the echoes into electrical signals, the thickness of the transducer changing in a direction orthogonal to the ultrasound beam traveling direction, a filter connected to the transducer for filtering the electrical echo signals from the transducer with the filter characteristic which is changed according to a change of the thickness of the transducer, signal processing circuit connected to the filter for processing the electrical echo signals passed through the filter to convert it into tomogram signal, and a monitor connected to the signal processing circuit for displaying a tomogram according to a tomogram signal from the signal processing circuit.

Abstract: An ultrasonic probe (1) for use with ultrasonic imaging apparatus for investigating the internal structure of a body contains a pair of pulse echo receivers (RA1, RB1; RA2, RB2; . . . ) for each pulse transmitter in a linear array of transmitters (T1, T2, . . . ). The two receivers (A,B) in each pair lie in a plane at right-angles to the pulse propagation axis of the associated transmitter and equidistant therefrom. The outputs from the two receivers in each pair are correlated by multiplying in multipliers (11.1, 11.2, 11.3) so that in use the time coincident components of the two waveforms in each receiver pair are emphasized, thus focussing the echo information in the longitudinal plane of symmetry (4) of the probe.

Abstract: An ultrasonic flaw detecting apparatus of electronically scanning type comprises a plurality of ultrasonic vibrator elements disposed in an arcuate array, wherein groups of N vibrator elements arrayed in the circumferential direction of an object under test are sequentially changed over to one another on one-by-one base to thereby scan an object under test with ultrasonic beams. By controlling phases of pulse signals applied to the individual vibrator elements, a region of focus of the ultrasonic beams is set at a predetermined depth of the object under test. For reception, only the echoes reflected from a predetermined focal range are selectively extracted by providing corresponding window or gate means.

Abstract: Slowly tapering the cone angle as a function of distance along the cone results in a horn transducer that has a sharp focus in the near field and a large depth of field. The horn is simulated by time delaying the excitation pulse sequence to an annular array. An ultrasonic imaging system, particularly for contact B-scanning, uses an annular array to simulate both a horn transmitter and a fixed-focus receiver. This device has good resolution over a large depth of field and is easy to implement.

Abstract: Multi-channel automatic on-line ultrasonic inspection system for real time high-speed pulse echo testing is done across the width of a hot moving workpiece, such as steel plates and the like. In addition to a multiplexed transducer array search unit, the system includes an adjustable ultrasound fluid couplant, a main ultrasonic instrument modified with a digital multi-channel R.F. attenuation controller and a digital automatic flaw gate controller combined as on-line calibration means. The calibration means automatically corrects echo pulses for attenuation errors due to effects of variations in workpiece alloy or composition and temperature, and timing errors due to effects of variations in thickness and transducer gap, respectively. System further includes an ultrasonic data buffer/controller (UDBC) for digitizing, encoding and storing corrected or uncorrected flaw area data passed by the flaw gate during workpiece movement.

Abstract: An ultrasonic imaging system comprises a transducer array including a plurality of elongated piezoelectric transducers successively arranged along a curved surface for emission of diverging beams of acoustic energy and an acoustic diverging lens affixed to the curved surface for increasing the angle of divergence of the emitted acoustic energy. The system includes a source for successively generating burst energy and means for selectively establishing a connection from the energy source to a subarray of the transducers to transmit a beam of acoustic energy therefrom and shifting the connection to the next subarray by at least one transducer in response to the generation of subsequent acoustic energy to cause the emitted acoustic energy to be angulated in an arc scan format. Means are provided for compensating for differences in energy level resulting from the differences in the path-length of the acoustic lens.

Abstract: The invention relates to an ultrasonic imaging system for diagnostic use or non-destructive testing. The system comprises a first array of ultrasonic transducers coupled to the object space wherein objects under examination are located or distributed; a second array of ultrasonic transducers coupled to a reconstitution space wherein the acoustic images of the objects are to be replicated; and time inversion means. The time inversion means has a set of waveform memories which first captures the ultrasonic signals from said objects, typically echos produced in response to suitable excitation, via said first array of ultrasonic transducers with suitable amplification and preconditioning as necessary. Then readouts of these signals are provided inversely in time which drive the second array of ultrasonic transducers with said time inverted signals to reproject inversely propagating ultrasonic wavetrains forming replicated acoustic images of the objects.

Abstract: A plurality of transducers is arranged successively on a common impedance matching layer of a resilient material. Each transducer comprises an elongated piezoelectric element having a width expansion vibrational mode, a pair of first and second electrodes attached to opposite surfaces of the element across its thickness and an elongated block of an impedance matching material disposed between the second electrode and the common impedance matching layer. The common impedance matching layer is bent to take the shape of an arch to conform to the surface of a frame structure which is convexed in the direction of propagation of ultrasonic energy. The piezoelectric elements are secured to the frame so that they bridge the parallel side members of the frame. The piezoelectric members are divided into a plurality of subgroups, each composed of successively arranged elements.

Abstract: A probe is provided which comprises a plurality of ultrasonic transducer elements, and is so arranged as to be capable of simultaneously transmitting and receiving ultrasonic beams of plural frequencies. Means is provided for changing the shapes of the effective acoustic field of the ultrasonic beams of each a predetermined number of frequencies by selectively operating the ultrasonic transducer elements or interchanging transducers. The shapes of the effective acoustic fields of the ultrasonic beams of the plural frequencies are made substantially coincident in accordance with the range of distance from the probe. Thereby, the measuring of the tissue or the like with coincident shaped beams of plural frequencies can be realized.

Abstract: In an exemplary embodiment, a transducer element row W.sub.1 through W.sub.m has a signal delay device for the delay of arriving echo signals in such a manner that phase balance of the individual signals result at the output. It is the objective of the disclosure to construct such an apparatus with which, given a specified number of transducers, the grating lobes in the directional response of the antenna are eliminated, and nevertheless the electronic outlay can be kept within boundaries. This objective is achieved in that the signals are transmitted, in groups, respectively, by the delay device to individual adders whose output signals are linked in a unit for quasi-multiplicative processing. In the case of digital technique, through binary signal processing, a considerable simplification results accompanied by the elimination of the interfering directional response of the resolution capability.

Abstract: The transmitter comprises an array of electro-acoustic transducers (1), each of which is connected to an oscillator circuit (9) which has a start input (11). The start inputs (11) successively receive start signals from a start signal generator (13) which comprises a number of comparators (15), each of which comprises a first input (17) and a second input (19). The first inputs (17) are together connected to an output of a sawtooth generator (21), the second input (19) of each comparator (15) are connected to a direct voltage source (23). A direct voltage source (23) is provided for each start signal to be successively generated at least some of the direct voltage sources being controllable in common.

Abstract: An ultrasonic transmitting and/or receiving transducer is disclosed which includes a piezoelectric body with electrodes at opposite faces thereof. At least one of the electrodes is in the form of an elongated strip conductor such that the transducer also functions as a lossy delay line. The beam pattern of the transducer is dependent upon the delay of the delay line. A high permeability member such as a ferrite body is located adjacent the elongated strip conductor to increase the distributed inductance of the delay line and, consequently, the delay thereof. The permeability of the ferrite body is controlled by use of a drive coil adjacent thereto. By time varying the drive current to the coil, the acoustic beam pattern is time varied. By using a spiral shaped elongated strip conductor on a cylindrical shaped piezoelectric body, a focusing transducer is provided.

Abstract: An ultrasonic scanning apparatus includes a transducer plate, a plurality of elongated, parallel driving line electrodes arranged on one surface of the transducer plate and a plurality of elongated, parallel grounding line electrodes arranged on the opposite surface of said transducer plate. The driving line electrodes and the grounding line electrodes intersect to effectively form a matrix of individual transducer elements capable of both emitting and receiving ultrasonic beams. The apparatus includes control means to sequentially activate selected arrays of the individual transducer elements to produce and focus the resultant ultrasonic beam and to sequentially switch selected arrays of the individual transducer elements to a reception mode to vary the effective reception area of the transducer.

Abstract: A method of and a device for ultrasonic examination of an object by means of a row of N electroacoustic transducers. Each time a group of M transducers (M.gtoreq.N) thereof is selected by means of a switching member. These M transducers are first included in transmission networks, transmission signals then being applied to the converters; subsequently, they are included in receive networks, receive signals then being applied to a display device. The transmission and/or receive signals are multiplied by weighting factors between 0 and 1. The sum of the weighting factors during transmission may deviate from that during reception. During transmission and/or reception, at least two different combinations of weighting factors are used, the sum thereof being each time the same. The scanning line density can thus be substantially increased.

Abstract: This ultrasonic imaging apparatus has an array (44, 52 or 100) of transducer elements (44, 50 or 104) for transmitting ultrasonic signals having a first predetermined center frequency (fc1) into an object (12) to be analyzed through use of the transmitted signals reflected from within the object. A means (150, 116-1 through 116-X and 120-1 through 120-X) is connected to transmit the ultrasonic signals from the array (44, 52 or 104) in a stepped array mode. A means (150, 116-1 through 116-X and 120-1 through 120-X) is connected to transmit the ultrasonic signals from the array (44, 52 or 104) in an angle scanning mode. There is a means (150, 128-1 through 128-X) for focusing the transmitted signals at a desired depth within the object (12). The reflected signals sensed by the apparatus have a second center frequency (fc2) less than the first center frequency (fc1) as a result of signal attenuation by the object (12).

Abstract: The ultrasonographer changes the frequency of ultrasound pulses emitted from an ultrasonic transducer as a result of adjusting the RF frequency of the transmitter burst exciting the broadband transducer; this adjustment takes place between pulse transmissions, while examining the patient. In a phased array imager utilizing baseband processing of received echo signals, the same adjustment supplies the corresponding frequency to the demodulator circuits. An alternative method of changing the system spectrum is to have a narrow bandwidth receiver whose center frequency is varied over the available bandwidth.

Abstract: Ultrasonic signals, for example, are provided with a fast-acting store which, at the same time, allows maximum flexibility in addressing. The signals arriving at the signal inputs of the signal store are apportioned into channel sections, and the channel sections occurring after each other in time may each be read in parallel formation into section addresses of the signal store. The section addresses may be read out again orthogonally following each other in time in such a sequence that, in combination, the original signals are again obtained.

Abstract: An ultrasonic imaging apparatus has an array (10 or 100) of transducer elements (14 or 104) for transmitting ultrasonic signals into an object (12) to be analyzed through use of the transmitted signals reflected from the object and sensed by the apparatus. The transmitted signals have a first predetermined center frequency. The reflected signals sensed by the apparatus have a second center frequency less than the first center frequency as a result of signal attenuation by the object. A means (70, 62 or 150, 152-1 through 152-X) is connected to select a number of transducers (14 or 104) in the array (10 or 100) for transmitting and/or receiving the ultrasonic signals based on the second center frequency. Adjusting the number of transmitting and/or receiving transducers (14 or 104) with changes in frequency produced by signal attenuation gives improved image resolution under a wider variety of use conditions than with prior art ultrasonic imaging apparatus.

Abstract: An ultrasonic transducer array for arc scan imaging systems comprises a plurality of elongated piezoelectric transducers arranged successively to define a convexed energy radiating surface. A plano-concave acoustic diverging lens is attached to the convexed surface to diverge the acoustic energy transmitted from the transducers in an increased steering angle. The transducers are assembled on an impedance matching layer which defines the convexed radiating surface. The acoustic impedance of the diverging lens is substantially equal to the acoustic impedance of the human body, while the acoustic impedance of the impedance matching layer is greater than that of the human body.

Abstract: The echo signals from ultrasonic transducer elements are filtered by a plurality of prestage band pass filters having different central frequencies and frequency pass bands. The filtered echo signals from those band pass filters are composed by an adder into a composite echo signal. This composite echo signal from the adder is filtered by a variable band pass filter whose central frequency is shifted and whose frequency band is fixed, whereby the echo signal components passed through the prestage band pass filters are extracted sequentially. The echo signal components from the variable band pass filter are converted by a signal processing circuit into a tomographic signal, which is displayed as a tomographic image by a display.

Abstract: An ultrasonic transducer arrangement having a matrix of oscillators, each such ultrasonic oscillator being formed of a matrix of columnar transducer elements which are electrically controlled together. The spaces between the individual transducer elements are filled with a filler material having an acoustic impedance which substantially differs from the acoustic impedance of the ultrasonic oscillator material from which the transducer elements are formed. The ultrasonic oscillators are provided with electrode strips which are arranged in parallel rows on one flat side of the matrix. The other side of the matrix is provided with electrode strips in the form of parallel columns, so as to be transverse to the direction of the electrode strips on the first side. This arrangement permits high-packing density of the transducer elements, resulting in high resolution which enables line focusing and a close approximation of point focusing.

Abstract: In an ultrasonic wave tomographic imaging system wherein an acoustic image in an object is focused on the ultrasonic wave receiving means by means of an ultrasonic wave lens in order to pick up an image of the desired tomographic plane in the object, the clearness of a tomographic plane image is much improved by a structure wherein the ultrasonic wave is not generated to unwanted regions other than the desired tomographic plane of the object by providing the ultrasonic wave generating means so that scanning occurs only as to the desired tomographic plane of the object, and a gate means is provided so that the ultrasonic wave receiving means can receive an acoustic image corresponding to the scanning in accordance with the scanning of the ultrasonic wave generating means.

Abstract: An ultrasonic diagnostic system for observing the state within a measured object by transmitting ultrasonic waves to the interior of a measured object such as the human body and by receiving acoustic waves reflected from the object. The system employs plural probe units which contain electric-acoustic transducers and are mutually isolated. A transmitting circuit causes the plural probe units almost simultaneously to transmit ultrasonic waves having different characteristics. A receiving circuit contains filters for isolating and extracting acoustic signals having characteristics corresponding to those particular transmitted ultrasonic waves from the other acoustic signals received. This system thereby obtains an acoustic image corresponding to each scanning line, and by means of scanning the measured object with each of the probe units, a display of the object's movement is obtained with plural scanning lines.

Abstract: Either a linear array ultrasound transducer or a phased array transducer is constrained to scan along a body in a single plane to derive data for enabling simultaneous display of static and real-time ultrasound images.