Siemens Aktiengesellschaft

Richard Ernst Soldner

Rudolf Rattmann

Karl Prestele

Alfred Walz

In a method and apparatus for displaying at least one acoustic propagation property that is present within a body part suitable for diagnosis by acoustic irradiation, ultrasound transmission signals are transmitted along scan lines into the body part by an ultrasound transducer arrangement. Ultrasound signals that have passed through the body part are acquired as transmitted sound signals with a further ultrasound transducer arrangement arranged opposite the first ultrasound transducer arrangement. Parameter values are calculated from the transmitted sound signals that characterize the acoustic propagation property along the scan lines. The parameter values are portrayed on a display dependent on the corresponding scan lines.

Method and apparatus for displaying acoustic signal transit times

An acoustic delay line includes electrodes on a monolithic piezoceramic substrate, which serve as electro-acoustic transducers for the delay line. The distance between said transducers defines the transit time, and thus the delay path. Each transducer may have electrodes on the same side of the substrate, in which case thickness of the substrate is less than or equal to one-half the wavelength of the highest frequency to be transmitted in the substrate, so as to prevent the formation of higher modes. Alternatively, each transducer may have congruent electrodes on opposite sides of the substrate, in which case the thickness of the substrate is less than or equal to the wavelength of the highest frequency to be transmitted. The substrate is polarized substantially parallel to the equipotential lines which arise in the substrate upon the application of a voltage to the electrodes. The acoustic wave which is generated by one of the transducers therefore traverses the delay path between said transducers as a plate shear wave. High-precision broadband and distortion-free delay lines can thus be realized for low frequencies, with small component dimensions despite long delay times.

Piezoceramic lamina acoustic delay line suitable for use in an

In the illustrated embodiment, ultrasonic transmitter/receiver elements are arranged along a curved formation within a housing containing a coupling medium which is a good conductor of ultrasonic energy (for example a water medium) and are successively excited to direct ultrasonic beam energy via the coupling medium to an ultrasonic window of the housing. The transducer elements are mounted at different angular orientations such that their beam paths converge external to the ultrasonic window. The curvature of a carrier for the transducer elements may be controlled to adjust the distance of the point of convergence beyond the window without changing the length of the acoustic path in the coupling medium, or the transducer elements and/or ultrasonic window may be bodily shifted to simultaneously change the length of the acoustic path and the distance of the convergence point beyond the window. Internal body regions accessible through narrow acoustic apertures at varying depths dependent on individual body characteristics may thus be reached for scanning by appropriate adjustment of the depth of the convergence point of the ultrasonic beam paths, the diverging beam paths beyond such depth providing for a sector scanning configuration within the desired body region.

Ultrasonic applicator for ultrasonic scanning of bodies

An ultrasonic applicator is illustrated for ultrasonic scanning of internal body regions, particularly for obtaining ultrasonic echo sectional views thereof for medical diagnostic purposes, wherein an ultrasonic transducer system directs sequential pulses of ultrasonic energy along successive beam paths converging toward a virtual focal point, and a planar reflector is interposed to reflect the energy pulses and is inclined at an angle deviating from 90.degree. relative to each incident beam path for the purpose of producing an actual convergence of the reflected beam paths externally of the applicator. The depth of the actual convergence point within the body to be scanned may be varied by means of a longitudinally adjustable acoustic window. The actual convergence point may also be shifted by angular adjustment of the reflector. The convergence of the reflected beam energy to a relatively narrow focus at a selectable distance in front of the acoustic window adapts the applicator to sector scanning of a body region accessible only through a relatively narrow acoustic aperture (e.g., between relatively dense bone structures).

Ultrasonic applicator for ultrasonic scanning of bodies and method of

Method of ultrasonic scanning of bodies

In an illustrated embodiment, a selective receiver receives a first echo impulse produced at the interface between the precursor water path and the subject under examination, as a measure of the precursor transit time (T.sub.v). Thereafter, each transmit pulse is synchronized with the receipt of such echo impulse so that multiple echoes resulting from such echo impulse coincide in time with desired echo signals, and thus do not disturb the accuracy of the display. By way of example, a trigger stage may respond to the interface echo to directly trigger transmission of the next ultrasonic pulse. The trigger stage may also actuate a first monostable with a time interval corresponding to the nominal precursor transit time (T.sub.v), a second monostable being triggered by the first monostable to establish the actual gating interval for receipt of the resultant interface echo signal. The gated interface echo signal may be compared with a standard level and any deviation used to control amplification of the receiver.

Ultrasonic examination apparatus operating according to the impulse-echo

A line sweep magnetic deflection system is triggered to display ultrasonic echo impulses during line by line scanning of a body region. Each trigger impulse produces a nonlinear saw-tooth voltage waveform as a function of time which when converted to a corresponding current waveform in the deflection coil produces a constant line deflection velocity for accurate display of echo signals in spite of nonlinearities in the electron optics of the oscilloscope, for example. High gain differential amplifier means force the coil current to conform to the voltage waveform during active line trace, and deviations during retrace intervals cause the application of an overvoltage to the coil driver stage, blocking a normal operating supply voltage therefor, and rapidly driving the coil to its initial energy state, thereby enabling a higher line sweep frequency with consequent optimum display resolution.

Oscilloscope for the image display of sectional planes of a body

An arrangement for the puncturing of internal body organs, vessels or the like, through the utilization of a puncturing cannula or hollow needle which will well reflect an ultrasound, as well as an ultrasound-echo sectional view apparatus having an ultrasonic applicator with an ultrasound scanning system for the surface-wide ultrasonic scanning of the body region which is to be punctured, and a display or viewing apparatus for rendering visible the echo-section images. On viewing apparatus, a targeting aid for the aiming of a suitable punctuating point in the echo sectional view, and on the ultrasound applicator a guide aide adjustable at least in the targeting direction of the aiming aside for the introduction of the puncturing cannula into the body region which is to be punctured.

Ultrasonic arrangement for puncturing internal body organs, vessels and

An ultrasonic applicator including a parabolic reflector for reflecting ultrasonic beam energy for ultrasonic sectional scanning particularly for medical diagnostic purposes, has its image registering system compensated for the variable sweep velocity of the ultrasonic beam energy within the body region under examination by the provision of a rotary mark carrier with a series of angularly offset marks of variable spacing such that as the mark carrier rotates at a constant rate in synchronism with the rotary ultrasonic transducer head, the marks are scanned at a relatively rapid rate as the ultrasonic impulses are reflected at the border regions of the parabola and are scanned at a progressively slower rate during transducing via points progressively closer to the central region of the parabola.

Ultrasonic imaging apparatus operating according to the impulse-echo

An arrangement for effecting ultrasonic-echo encephalography, including at least two ultrasonic heads, as well as a recording arrangement for the ultrasonic waves which are received from the skull of a patient, and having at least one marking device associated therewith for marking the position of the theoretical median echo. The marking arrangement incorporates a time measurement element for determining the transit time of the ultrasonic wave through the skull portion being examined by means of the sound-penetrating operation which, after switching over to a reflecting operation, so controls an impulse generator in that the latter, periodically in beat with the ultrasonic radiation, and delayed with respect to the timepoint of the ultrasonic entry into the skull examination area by the amount of the previously determined skull transit time, as to produce a marking impulse at the recording arrangement.

Arrangement for ultrasonic-echo encephalography

An ultrasound applicator for ultrasonic-echo planigraphic imaging apparatus, consisting of a plurality of ultrasound transducer elements which are located on the application surface of a carrier portion in at least one row adjacent to each other. The carrier portion is provided with a guide slot for the puncturing cannula which extends across the transducer row along the longitudinal direction thereof, and which reduces from a predetermined maximum slot length at the surface remote from the application surface of the carrier portion to a minimum slot length at the application surface.

Ultrasound applicator with guide slot for puncturing cannula

An ultra sound examining device operating according to the impulse echo process and used for medical purposes comprises an ultra sound sending-receiving system the sender of which transmits ultra sound impulses in predetermined time intervals into the object being examined through a precursor stretch connected in front of the system, for example, water precursor stretch. There is also an echo impulse representing device operated depending upon the transmitted impulses which represents echo impulses of each transmitted impulse received by the receiver one after the other corresponding to the time sequence of their appearance. The invention is particularly characterized in that the time interval between two succesive transmitted impulses of the ultra sound sender has a value which is smaller than the sum of the precursor time of the ultra sound impulses in the precursor stretch and the representation time of the echo impulses on the representing device. However, even the smallest value is not less than the representation time.

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Erlangen, Germany

Richard Ernst Soldner