Siemens Aktiengesellschaft

Dieter Hassler

Elmar Trautenberg

Helmut Reichenberger

Georg Naser

Robert Schwarz

Heinz Kresse

Wolfgang Mittelstaedt

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. For this purpose, the invention provides an additional horizontal axis, intersecting the vertical axis just a few millimeters below the surface of the fluid, which is attached to a second angled support rotating around a vertical axis. From this additional horizontal axis is suspended a revolving, essentially L-shaped support bearing a second ultrasonic transmitting and receiving system on its free end that is capable of revolving through the median perpendicular to the central opening in the cover, and whose direction of radiation is aligned to the mid-point of the central opening in the cover. An ultrasonic tomography device designed in accordance with the invention is particularly suited for use in medical technology.

Ultrasonic tomography device

In exemplary embodiments, an ultrasonic transducer serves as vibration generator. It is an object of the disclosure to construct such an apparatus which, with the simplest technical construction, is functionally reliable and can be operated in a very adaptable manner and which is simultaneously especially productive with regard to the desired destruction effect. In accordance with the disclosure this object is achieved in that an ultrasonic transducer to be focused on the calculus serves as a direct acoustic irradiator for the calculus, which irradiator has a surface area such that the sound energy per square unit along the transmission path is sufficiently small so as to avoid tissue damage on the one hand, but is sufficiently great at the focus point that is suffices for the destruction of the calculus disposed at the focus, on the other hand.

Apparatus for destroying calculi in body cavities

Due to a different configuration of the ultrasonic beam as well as different signal gate adjustments, two different doppler signal collection regions (V.sub.m1, V.sub.p) of the flowing medium are selectable. To further develop the state of the art, without excessively increased technical outlay, at least the flow velocity (v) and/or the flow cross-sectional area (F) are to be measured, preferably simultaneously with the volume flow (Q), independently of the irradiation angle of the ultrasound into the flowing medium. This is achieved through selection of a third doppler signal collection region (V.sub.m2), power measurements (P.sub.m1, P.sub.p, P.sub.m2) from all three regions (V.sub.m1, V.sub.p, V.sub.m2) and the calculation from the powers together with additional known parameters of the signal collection regions such that, with cancellation of the angle-dependency, the respectively desired flow quantity (F, v, Q) directly results. A preferred implementation is for the purpose of diagnosis of blood flow.

Method and apparatus for conducting flow measurements on flowing media

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.

Plane reconstruction ultrasound tomography device

An ultrasound tomography device for scanning an object under examination from a plurality of directions. Coronal slice images of the plane or planes near or at the female breast wall are obtained. A sagittal scanner is used to obtain numerous small sectional oblique views of the slice to be viewed. A full image of the coronal slice plane is reconstructed through section by section combination of the images obtained from the several small sagittal sections. By providing the sagittal scanner with a scanning motion as well as with translational mobility a full composite view is provided.

Ultrasound tomography device

In an exemplary embodiment, an ultrasonic array has an installation for dynamic focusing at least in the transmitting mode. It is the object of the disclosure to avoid excessively great time loss, and yet to permit dynamic focusing also in the transmitting mode. This object is achieved in that, in the case of a specifiable number of depth regions (with a respective fixed focusing in each depth region) preferably associated with each scanning line of the ultrasonic scanning, the transmitting/receiving cycle for each fixed focusing is progressively introduced in such a manner that, for every depth region of each such scanning line, transmission is effected at such a time-point which immediately follows, for example, that time interval in which echo information was received from the chronologically prior-scanned depth region for such scanning line. More generally, the second ultrasonic pulse for a given scanning line occurs while echo signals due to the first pulse are still returning from the depth extent of the body which is under examination.

Apparatus for ultrasonic scanning

In an exemplary embodiment particularly applicable to the examination of the human body, for the purpose of energizing with the aim of transmission of an ultrasonic pulse, a high frequency pulse of specific duration and amplitude is in each instance supplied to the ultrasonic transducer. In spite of a substantially reduced maximum energizing voltage, optimum conditions are to be created with regard to the intensity of pulses to be radiated with a simultaneous short pulse duration, so that preferably also switches which are restricted in their maximum switching voltage can be utilized for controlling the ultrasonic transducers. This becomes possible by virtue of the fact that each ultrasonic transducer is subjected to a specifiable number of periods of a sinusoidal or sine-like oscillation with a frequency which energizes the ultrasonic transducer at its useful resonance frequency. Subsequently thereto, a stop signal, preferably an additional number of periods of sinusoidal oscillation of smaller amplitude and with a phase jump of 180.degree. is supplied to the ultrasonic transducer. After-oscillations of the transducer are thus extinguished with certainty.

Method and circuit arrangement for energizing ultrasonic transducers

In an exemplary embodiment, an examination object is scanned line-by-line with an ultrasonic beam and the developing echo signals are correspondingly recorded line-by-line on an image recording installation to form a visible image. The echo recording is to ensue amplitude-compressed without a simultaneous deterioration of the resolution or of the image sharpness. To this end, a preselectable plurality of echo lines (Z.sub.n through Z.sub.n+3) which preferably determine the breadth of a surround field for echoes to be depicted together with a current line (Z.sub.n+4) are always written into intermediate memories. Subsequently, the stored and, under certain conditions, current echo signal information are supplied to an evaluation installation. During a specific section time, which determines the depth (.tau.) of the surround field, a mean value of the echo intensity in the surround field is here at least approximately comprehended. This, if necessary after previous dynamic limitation, is placed in ratio at a ratio former to the echo respectively to be depicted. The ratio signal is the recording signal for the recording installation.

Process and installation for producing and recording ultrasonic

In an illustrated embodiment an array of ultrasonic transducer elements is combined into a first transmitting surface to emit a first transmit signal, and then in alternation with blanking intervals is combined into receiving surfaces of progressively increased size for the reception of echo signals and for constructing a first image line of a first partial image. A second transmitting surface of lesser size then emits a transmit signal and further combinations of transducer elements are activated during time intervals thereafter which correspond to the blanking intervals of the first image line. Such sequential lines may form a composite line on a visual display. A planar array of transducer elements may have its successive receiving surfaces of varying size electronically focused either in the scan direction or in the layer thickness direction, or the array can have mechanical curvature to provide a desired focus in the layer direction. A circuit arrangement is preferred which simplifies the control of switching and minimizes the number of electronic focusing channels while still achieving a relatively high image frequency.

Each receiving or transmitting circuit for a respective transducer element includes an individually controllable buffer amplifier which is so operated as to avoid detrimental switching transients. For example, the buffer amplifiers in the receiving circuit may have input switches closed immediately after a transmit pulse and prior to the actual receiving phase. Then output switches of the buffer amplifiers to be activated are closed in the receiving phase, but transients so produced are blocked by the high reverse attenuation of the buffer amplifiers. The input switches may be actuated prior to activation of the transducer elements in receive mode and may serve to simultaneously supply operating voltage to the respective associated buffer amplifiers, the buffer amplifiers all being switched off during transmit mode to block transmit energy from non-active transducers. The transducers of a column of a transducer array may have their outputs summed by means of the buffer amplifiers acting as a voltage controlled current sources.

The apparatus comprises an ultrasonic transducer for the purpose of scanning an examination subject, and an image display device for representation of the ultrasonic information signals in the form of a display image. In accordance with the illustrative disclosure, an arrangement of electric frequency filters is associated with the ultrasonic transducer, said frequency filters manifesting a frequency response which is essentially the inverse of the frequency response being imposed on the ultrasonic impulses by the attenuating examination subject in the ultrasonic-transmit path. The imaging apparatus finds application particularly in medical ultrasonic diagnosis.

Ultrasonic imaging apparatus operating according to the impulse-echo

An arrangement for the determination of the effective value and/or the performance or power and, for example, also the cross-power of electrical signals, in particular those Doppler signals which are received in ultrasonic-Doppler blood flow measurement. The arrangement includes an amplifier for the present electrical signal regulatable in amplification which, on the one hand, is connected into a control loop or circuit for regulating the degree of amplification for the purpose of producing constant amplifier power outputs and, on the other hand, connected into a measuring circuit for determination of the degree of amplification which adjust itself at the current power constant-regulation of the amplifier.

Arrangement for determining the effective value and/or the power of

To compensate the Doppler flow measurement for the angle of the ultrasonic beam relative to the flowing medium, the ultrasonic applicator includes a mechanical electrical angular position sensor for generating a signal as the applicator is shifted from a perpendicular relationship to the flow axis to a desired oblique angular relationship. As a particularly preferred embodiment, a rotary member is held relative to the flow axis as the applicator axis is rotated, placing a strain gauge under a proportional tension to unbalance a bridge circuit. A further development provides a sensor output as a function of the cosine of the angle of interest so that the bridge output is in the form required to compensate the flow measurement signal without a prior trigonometric operation thereon.

Apparatus for the measurement of flowing media according to the

An arrangement for measuring cross-sectional fluctuations on conduits which are streamed through by fluids, particularly blood vessels, pursuant to the Ultrasound-Doppler method, through the utilization of an ultrasound transmitter-receiver system, a Doppler apparatus for determining the power or intensity of Doppler signals, as well as a dividing element for the obtained Doppler signal intensities. A single ultrasound transmitter-receiver is provided for the irradiation or projection of ultrasound into the liquid and for the receipt of the ultrasound reflected from the liquid, wherein an installation is associated with the Doppler apparatus for the formation of the intensity of the Doppler signal with on the one hand, the amplitude fluctuations, as well as, on the other hand, a timewise arithmetic median value of the intensity without material fluctuations, and in which the dividing element is connected to this installation for the purpose of forming the quotient from these intensities. The arrangement utilizes such quotient in the provision of indications of volumetric flow and conduit elasticity.

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Uttenreuth, Germany

Dieter Hassler