Abstract: An ultrasonic probe has an elongated form with an end. A transducer element array is disposed in the probe for emitting ultrasonic wave frontward with respect to the end of the probe and receiving echo ultrasonic waves. The transducer element array converts the received echo ultrasonic waves into corresponding electric echo signals. The electric echo signals are processed according to a predetermined aperture synthesis technique, and thereby an image signal is generated on the basis of the electric echo signals. An image of a region in front of the end of the probe is reproduced in response to the image signal.

Abstract: An acoustic characteristic measurement method comprising transmitting into a specimen an ultrasonic probe pulse and a pulse formed by the superposition of the probe pulse centroid on a pump pulse of a lower frequency than that of the probe pulse at a portion where the particle acceleration of the pump pulse is at a peak, receiving reflections of the transmitted signal from two or more reflecting points that are at different depths in the specimen, frequency-analyzing the received signals and obtaining a spectral ratio, and using the spectral ratio to measure the distribution in the specimen of the degree of spectral separation and the crossover frequency.

Abstract: The present invention relates to an ultrasonic examination apparatus which transmits ultrasonic waves into a body to be examined and receives the echo signals therefrom for examination of the inside of the body. The ultrasonic examination apparatus measures acoustic characteristics such as nonlinear parameter within the body using the fact that the characteristic of the reception ultrasonic wave from the inside of the body is varied in accordance with variation of the characteristics within the body. The ultrasonic examination apparatus has first and second ultrasonic transducers for transmitting first ultrasonic pulse and second ultrasonic pulse, respectively. The frequency of the second ultrasonic pulse from the second ultrasonic transducer is higher than that of the first ultrasonic transducer. The first and second ultrasonic pulses are superimposed and transmitted into the body.

Abstract: An ultrasonic diagnostic apparatus detects variations of an acoustic characteristic to obtain the fluctuation of temperature within a body to be examined. The ultrasonic diagnostic apparatus includes an ultrasonic transducer for transmitting an ultrasonic wave and receiving the reflected ultrasonic wave which is in turn converted into an electric signal. The signal is phase-detected in accordance with a plurality of gate intervals or a plurality of window interval to detect a phase difference therebetween. The relative variation of velocity dispersion before and after heating of the body is obtained on the basis of the phase variation resulting from the variation of the ultrasonic drive frequency.

Abstract: An ultrasonic tomographic diagnosis apparatus suitable for skin disease displays a first ultrasonic tomographic image (12) of an object of a fairly broad area, wherein sizes in depthwise direction (X in FIG. 1) displayed in an enlarged scale in relation to sizes in a direction (Y in FIG. 1) on the skin surface, and further a second ultrasonic tomographic image (13) of an object wherein sizes in depthwise direction and sizes in the direction on the skin surface are displayed in substantially proportional to actual size relations, for a selected part marked by a marker (14) on the first tomographic image (12).While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all modifications and changes as fall within the true spirit and scope of the invention.

Abstract: A first ultrasonic pulse formed by the superposition of a probe pulse on a pump pulse having a frequency lower than the center frequency of the ultrasonic probe pulse where the particle velocity of the pump pulse is in the vicinity of zero in addition to which the particle acceleration of which is at a constant portion, and a second pulse formed by the superposition of the probe pulse center frequency on the peak particle velocity portion of the pump pulse, as well as a probe pulse alone, are transmitted into a specimen before and after it is heated and the reflections of the transmitted signals from two or more reflecting points that are at different depths in the specimen are received. The received signals are subjected to frequency analysis and the spectral shift and the phase shift of the probe pulse and superposed pulses are obtained, and from these values the attenuation of the probe pulse between the differing depths is determined.

Abstract: In an ultrasonic imaging system echo signals representative of the amplitude of ultrasonic energy returning along a plurality of angularly spaced paths are sampled at a constant speed and stored into a buffer memory. At a speed inversely proportional to the cosine of the angle of said path with respect to a reference line the echo samples are read out of the buffer memory and written into a specified area of a graphic memory at a constant speed in the direction of the rows thereof and at a speed proportional to the tangent of the angle of the path with respect to the reference line in the direction of the columns thereof. At a constant speed echo samples are read out of the graphic memory in the directions of the rows and columns and applied to a monitor to be displayed in a raster scan field.

Abstract: A digital signal processing apparatus is shown which is applicable for real time operation in the power spectrum of the detected outputs of ultrasonic Doppler blood flowmeter. The apparatus comprises a digital operating means, a memory means which is connected to said digital operating means to transfer data thereto and receive data therefrom, a fixed instruction generating portion for generating operating code for the digital operating means and addresses for the memory means, a read only memory for storing data of a squaring operation which has address inputs at the bit position selected as most suitable from the input data bus line of said digital operating means, an overflow detecting means when input data exceeds the region of the address input, and digital saturation circuit, whereby the power spectrum can be calculated by fundamental algorithm of WFTA having a smaller number of operating steps than algorithm FFT.

Abstract: Ultrasonic echo signals are detected in phase and integrated with a period corresponding to an ultrasonic pulse. The integrated values are sampled and the difference between two integrated values is successively frequency-analyzed.

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: 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: Ultrasonic echo signals are successively sampled and converted to digital echo data which are written into a first digital memory column by column and then read out row by row into a first buffer memory. The digital echo data which are derived in response to beams successively transmitted in a predetermined direction are written into columns of a second digital memory and read out of the memory in rows into a second buffer memory. The data stored in the first and second buffer memories are read out for digital-to-analog conversion and selectively applied within a television "frame" interval to control electron beam intensity of a single cathode ray tube so as to present tomographic and cardiographic images in different display areas of the tube.

Abstract: An ultrasonic imaging system includes a linear array of transducers of which a group of successively arranged transducers is selected and successively shifted to the next by at least one transducer. The transducers of the selected group are successively activated at respective delay times to transmit a radial scan beam which appears to emanate from a hypothetical point source located behind the transducer array. A scan converter is provided for conversion of analog echo signals in sector scan format to digital echo data in raster format for visual display.

Abstract: A sector scan ultrasonic imaging system comprises a source of a plurality of square wave pulse trains each being delayed by a unit quantization time with respect to adjacent trains, and a plurality of transmitter circuits corresponding to the elements of a transducer array. The duration of each square wave pulse is an integral multiple of the unit quantization time interval. Each transmitter circuit includes a read only memory in which a set of different digital delay time data is stored for the corresponding transducer element and is arranged to be retrieved in response to each angle increment of the ultrasonic beam transmitted from the array. Further included are a data selector for selecting a pulse train in response to a pulse train selection data retrieved from the memory and a programmable counter for counting the pulses of the selected train to generate an output in accordance with a pulse selection data retrieved from the memory.

Abstract: A focusing circuit for focusing an array of transducers of an ultrasound imaging system includes a variable delay line comprising a plurality of summing amplifiers and a plurality of variable delay elements provided between successive summing amplifiers. A plurality of switches is provided for respectively connecting the transducers to selected summing amplifiers. The amount of delay of each variable delay element is individually controlled so that the corresponding electrical signals derived from the transducers arrive in phase at the output end of the variable delay line.

Abstract: A scan converter is disclosed for use in a sector scan type ultrasound imaging system in which ultrasound echo signals return from targets along a plurality of radial scan lines distributed in a sector field with a substantially equal tangential angular increment with respect to a reference line. The scan converter comprises a sampling circuit which samples the echo signals at a speed inversely proportional to the cosine of the angle of deflection of the radial scan lines with respect to the reference line so that the sampled points align themselves in lateral lines perpendicular to the reference line. The sampled echo signals are converted into digital echo data and stored in a random access memory in the direction of its columns. The stored data are retrieved serially in the direction of the rows and fed into an interpolator for making interpolations between the successively retrieved echo data.

Abstract: Beam deflection delay time data of (L.times.M) data bits are stored in a read-only memory from which each datum is retrieved successively when the ultrasound beam is deflected to a given angle and repeatedly accumulated in a digital adder through a latching circuit connected between the output and input of the adder, where L is the number of discrete steps of deflection angle and M is a binary number representing the total delay time of piezoelectric transducers. The successively latched data is distributed to respective programmable counters for presetting the count values thereof to store therein respective delay time data. High frequency count pulses are supplied to the counters after the latter has been preset for delivery of carry outputs to the associated piezoelectric transducers.

Abstract: An ultrasound diagnostic apparatus includes a linear array of piezoelectric transducers or plates with a width-to-thickness ratio of less than 0.8 and a control circuit which includes a transmitter and a receiver. The transmitter comprises a plurality of transmitting channels each including a local oscillator for generating an ultrasonic pulse in response to a clock signal. The plurality of such ultrasonic pulses are applied through a switching network to a selected group of successively arranged piezoelectric transducers to transmit a beam of ultrasonic energy into a human body. Each of the ultrasonic pulses is phase shifted and amplitude modulated with respect to the ultrasonic pulses of the other transmitting channels to provide phase and amplitude taper which results in a narrow width beam through the depth of the body.

Abstract: An ultrasonic probe particularly suitable for ultrasonic diagnostic equipments of the electronic scanning type is made up of a multiplicity of piezoelectric transducer elements, each in the shape of a rectangular plate with electrode films coated on both sides, arranged in a row at intervals and an acoustic impedance matching layer placed on the row of the transducer elements. The width-to-thickness ratio of each piezoelectric plate takes a value not greater than 0.8 and preferably between 0.4 and 0.7 so that the plate can vibrate in width expansion mode. It is highly preferable that the impedance matching layer has a laminated structure given by two layers which are different in acoustic impedance of the respective materials and individually have definite thicknesses.