EP0170072B1 - Phased-array apparatus - Google Patents

Phased-array apparatus Download PDF

Info

Publication number
EP0170072B1
EP0170072B1 EP85108128A EP85108128A EP0170072B1 EP 0170072 B1 EP0170072 B1 EP 0170072B1 EP 85108128 A EP85108128 A EP 85108128A EP 85108128 A EP85108128 A EP 85108128A EP 0170072 B1 EP0170072 B1 EP 0170072B1
Authority
EP
European Patent Office
Prior art keywords
delay
phased
case
array
elements
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85108128A
Other languages
German (de)
French (fr)
Other versions
EP0170072A1 (en
Inventor
Ulrich Saugeon
Gert Hetzel
Dietmar Dr. Hiller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Priority to AT85108128T priority Critical patent/ATE46783T1/en
Publication of EP0170072A1 publication Critical patent/EP0170072A1/en
Application granted granted Critical
Publication of EP0170072B1 publication Critical patent/EP0170072B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/34—Sound-focusing or directing, e.g. scanning using electrical steering of transducer arrays, e.g. beam steering
    • G10K11/341—Circuits therefor
    • G10K11/346—Circuits therefor using phase variation

Definitions

  • the invention relates to a phased array device for the ultrasound scanning of an object with a number of ultrasound transducer elements, to which delay elements are assigned at least for the reception case.
  • the prior art provides for setting the delay times with the aid of LC delay lines which are provided with setting taps.
  • This relatively inexpensive solution is particularly suitable for short delay times, i.e. for non-pivoting scanning devices, e.g. B. for a linear array.
  • the LC delay lines have a band-limiting effect for higher frequencies. They each represent a low pass, the corner frequency of which can be approximately 5 MHz.
  • component tolerances largely affect the accuracy of the overall deceleration. For this reason, LC delay lines for transducer or converter frequencies are generally only used up to approx. 3.5 MHz. This technique is also called "baseband technique".
  • DE-OS 3004689 describes a reception delay system for use in an ultrasound imaging system, in which a variable pre-delay element is connected in series with the transducer and a main delay element in each channel.
  • the pre-delay elements are mainly used for fine tuning, i.e. to allow a gradual adjustment of the delay steps that normally cannot be performed on the main delay elements.
  • This arrangement makes it possible, in particular, to achieve signal coherence over a relatively large range of possible signal frequencies and different distances between the converter elements. For this purpose, however, this circuit arrangement requires a large number of delay elements.
  • DE-OS 2736310 specifies a delay arrangement in which a small, adjustable delay line is inserted between the transmitters or converters and the taps of a main delay line. These taps on the main delay line are selected such that the array is focused along a desired scan angle or direction. On the other hand, the small delays are changed during a scan in said direction in order to change the focus of the arrangement from the minimum range to the maximum range. Since the selected taps of the main delay line are not switched over in a desired direction during the scanning, the circuit principle only gives sufficiently coherent signals with small apertures.
  • Higher transducer frequencies can be processed using LC delay lines by downmixing to an intermediate frequency below 3.5 MHz.
  • downmixing technology requires a constant signal bandwidth and transmission pulse length for the individual converter signals.
  • the temporal transmit pulse length should be changed in the interest of good resolution when transitioning to high transducer frequencies, i. H. be reduced.
  • SAW filter technology see, for example, Ultrasonics, Vol. 17, pp. 225-229, Sept. 1979.
  • SAW filter technology For this purpose, it is necessary to mix the received signal of the individual ultrasound transducer element upwards in order to get into the high frequency band of 20-50 MHz required in SAW technology. After the summation of the individual received signals of the phased array, it is then necessary to mix down again.
  • Disadvantages of the SAW technology are the fact that up-mixers have to be used in each channel, which means a considerable outlay, and the difficulty in achieving a sufficiently fine gradation of the delay times in the SAW filters.
  • Up and down mixes associated with a phased array device are e.g. B. from Fig. 11 of DE-PS 2854134 known.
  • a digital delay technique in a phased array device is described in EP-PS 0027618, in particular in FIGS. 1 and 2.
  • Quadrature technology (cf. DE-PS 2854134, Fig. 8), in which two delay channels are used, the signals of which are phase-shifted by 90 °.
  • Quadrature technology requires a relatively high level of effort, since two channels per converter element are required for signal processing.
  • the aim of the invention is to create a phased array device which enables a high degree of accuracy in the adjustment of the control angle and yet only requires a comparatively small outlay.
  • this object is achieved according to a first basic embodiment according to patent claim 1. It is therefore possible to use several adjacent channels, e.g. B. 4 to summarize for signal processing.
  • the respective control angle can be set very precisely because of the use of components with fixed component-specific delay times (tolerances) and the digital memory, especially some shift registers. There is no fear of the delay drifting even after the phased array device has been used for a long time. As a result of the high accuracy in the setting of the control angle, there is also a high level of accuracy in the focusing and thus a high resolving power. This is of particular interest when using concurrent focusing in the case of reception.
  • the phased array device according to FIG. 1 which is used in particular for medical imaging, consists of a large number of individual ultrasound transducer elements E1, E2,... E64, which are used both for the emission and for the reception of ultrasound signals be used.
  • E1, E2,... E64 which are used both for the emission and for the reception of ultrasound signals be used.
  • the received ultrasound signals must be delayed with the high accuracy described above.
  • the number of ultrasonic transducer elements should be large. In the present case, the number 64 with an element spacing of ⁇ / 2 is a good compromise.
  • the received ultrasound signals are provided with a short and a long delay. This makes it possible to combine adjacent signal processing channels. As will become clear later, 4 channels are combined in FIG. 1.
  • the device contains a mixed delay technique, namely an analog pre-delay and a digital main delay. So it's a hybrid solution.
  • the analog pre-delay is a fine delay. It takes place in an area labeled X. A total of 64 channels are provided in this area X. The fine deceleration takes place between 0 and 2 ⁇ .
  • Area X is followed by area Y, which only comprises 16 channels. In this area Y there are amplifiers that can be controlled as a function of depth.
  • Area Y is followed by area Z, which also comprises 16 channels. There is a long-term delay here.
  • each ultrasound transducer element E1 to E64 is followed by a preamplifier V1 to V64 with a fixed gain.
  • a multiplexer M1 to M64 is in turn connected downstream of these preamplifiers V1 to V64.
  • the respective multiplexer M can be supplied with clock pulses by a control device C, which is indicated by an arrow on the respective block M1 to M64.
  • the multiplexers M1 to M64 are each analog Predelay element T1 to T64 assigned. Its delay time, in particular in the range from 0 to 600 nsec, can be set using the associated multiplexer M1 to M64.
  • the pre-delay elements T1 to T64 can in particular be LC lines with a number of taps, e.g. B. with 16 taps. With such LC lines there is a delay which is precise enough for the purposes at hand.
  • the fine deceleration is dynamic, i.e. switchable while receiving each ultrasound line. In this way, dynamic focusing can be achieved.
  • the delay elements T1 to T4 are connected to a common summing element S1, for example.
  • z. B. also the delay elements T61 to T64 connected to a common summing element S16.
  • the fine delay comprises the time period of at least 2 ⁇ in order to be able to combine four such neighboring elements.
  • the value 2 ⁇ is an empirically found variable. It represents a compromise that can be applied to most ultrasound applicators based on the phased array principle. Instead of four channels, two, six or eight channels could be combined.
  • the combined received signal obtained in this way is amplified depending on the depth with the aid of controllable amplifiers TGC1 to TGC16, in order to then be able to use the A / D converter dynamics.
  • FIGS. 1 and 2 After the amplification in the amplifiers TGC1 to TGC16, there are two implementation options, which are shown separately in FIGS. 1 and 2.
  • the received signal is sampled using the quadrature method, ie in complex form.
  • the output signal of the amplifier TGC1 is fed to a delay element which consists of a memory N1 and two analog-digital converters W1-1 and W1-2 connected upstream of it.
  • the two converters W1-1, W1-2 break down the received signal into a real and an imaginary part.
  • the converter W1-1 generates the in-phase term or cosine component, while the converter W1-2 provides the quadrature term or sine component.
  • the downstream memory N1 is preferably a shift register. This is e.g. B. scanned in ⁇ / 8 steps, for which purpose it is supplied by the control device C corresponding control pulses.
  • the coarse delay elements which are connected downstream of the further amplifiers TGC2 to TGC16, are constructed accordingly.
  • the output signal of the adder A consists of an imaginary part i and a real part q, so it is complex. From these two parts i and q, the magnitude of the signal can be formed according to the relationship ⁇ i 2 + q 2 , which can be displayed on a screen.
  • each channel has a series connection of an analog-digital converter W1 to W16 with a memory N1 to N16 controlled by a control device C.
  • the analog-to-digital converter W1 to W16 is each subjected to a sampling frequency f by the control device C '. This is preferably somewhat higher than the previously stated value of 10.5 MHz.
  • sampling frequency f can be below 20 MHz.
  • FIG. 3 shows a fully digitized implementation of the delay concept for a phased array device, in which the delay is again divided into a fine delay (see area X) and a coarse delay (see area Z).
  • the delay is again divided into a fine delay (see area X) and a coarse delay (see area Z).
  • 64 channels are again provided in area X of the fine delay, while only 16 processing channels are provided in the subsequent coarse delay area Z.
  • the 64 ultrasound transducer elements E1 to E64 are each followed by a depth compensation amplifier TV1 to TV64.
  • These depth compensation amplifiers can be regulated and correspond to the amplifiers TGC1 to TGC16 of FIGS. 1 and 2.
  • the received signal of each element E1 to E64 is amplified depending on the depth. It is then digitized using an analog-to-digital converter AD1 to AD64.
  • these analog-digital converters AD1 to AD64 are operated at a higher frequency than those in FIGS. 1 and 2, for example at a frequency f of 28 MHz, in order to be able to work with ⁇ / 8.
  • each of the shift registers VL1 to VL64 can comprise a total of 16 stages, while each of the shift registers VR1 to VR16 contains four times these 16 stages.
  • the same basic building blocks can be used in both types of shift registers.
  • the shift registers VL1 to VL64 correspond in their function to a combination of the multiplexers M1 to M64 and the time delay elements T1 to T64 from FIG. 1.
  • the output of four such shift registers, e.g. B. VL1 to VL4, each to adjacent ultrasonic transducer elements, for. B. E1 to E4, are each connected together to a summing element S1 to S16.
  • a different number e.g. a number of 8 channels.
  • the delay times of the individual shift registers VL1 to VL64 can be changed under computer control during the reception of an ultrasound line, in particular in order to achieve dynamic focusing. For this purpose, their control inputs are connected to a control device C ".
  • the outputs of the individual summing elements S1 to S16 are each connected to an addition element AGL via an assigned shift register VR1 to VR16, which bring about the longer of the two delays. This sums up the individual summarized and delayed signals.
  • an output signal s' which is high-frequency compared to that of FIGS. 1 and 2. This high-frequency output signal s' corresponds to the amount and can be used for image display. However, the two signal components i and q could also be derived from this high-frequency output signal s'.
  • the embodiment according to FIG. 3 also results in precise setting and control of the delay.
  • the swivel can again be effected via the delay elements for the coarse deceleration, which are immediately upstream of the adder AGL.
  • the shift registers VR1 to VR16 can be set.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

Phased-array apparatus has a number of ultrasonic transducer elements (E1 to E64) to which are associated delay line elements (M1, T1 to M64, T64, W1-1, W1-2, N1 to W16-1, W16-2, N16; W1 to W16; VL1 to VL64, VR1 to VR16) to provide reception. In order that the control angle may be adjusted with high accuracy, according to the inventive principles delay line elements are provided for the received signals with a short and with a long delay, and several adjacent channels are combined for signal processing. Due to this arrangement, economical constructions of embodiments of the invention are realized.

Description

Die Erfindung betrifft ein Phased-Array-Gerät für die Ultraschall-Abtastung eines Objektes mit einer Zahl von Ultraschall-Wandlerelementen, denen Verzögerungsglieder zumindest für den Empfangsfall zugeordnet sind.The invention relates to a phased array device for the ultrasound scanning of an object with a number of ultrasound transducer elements, to which delay elements are assigned at least for the reception case.

Bei einem Phased-Array-Gerät, also einem elektronischen Sektor-Scanner, muss die Änderung der Verzögerung der Signale der einzelnen Ultraschall-Wandlerelemente im Sende- und Empfangsfall in sehr kleinen Schritten erfolgen, um Fehler bei der Einstellung des Steuerwinkels zu vermeiden. Infolge des grössten Steuerwinkels von meist ±45° bezüglich der Normalen der Wandterelementreihe sind bei grossen Steuerwinkeln relativ lange Verzögerungszeiten erforderlich, deren Länge zusätzlich noch stark von der gewählten Aperturlänge (Länge der aktiven Antenne) abhängt. Zum Ausgleich der Auflösungsänderung mit der Tiefe wegen der begrenzten Tiefenschärfe der fokussierten Apertur ist es zweckmässig, den Empfangsfokus mitlaufend anzupassen.In the case of a phased array device, that is to say an electronic sector scanner, the change in the delay in the signals of the individual ultrasound transducer elements in the case of transmission and reception must be carried out in very small steps in order to avoid errors in the adjustment of the control angle. As a result of the largest control angle of usually ± 45 ° with respect to the normal of the row of converter elements, relatively large delay times are required for large control angles, the length of which also depends strongly on the aperture length selected (length of the active antenna). In order to compensate for the change in resolution with the depth due to the limited depth of focus of the focused aperture, it is expedient to adapt the receiving focus concurrently.

Der Stand der Technik sieht eine Einstellung der Verzögerungszeiten mit Hilfe von LC-Verzögerungsleitungen, die mit Einstellabgriffen versehen sind, vor. Diese relativ preiswerte Lösung eignet sich vor allem für kurze Verzögerungszeiten, d.h. für nicht schwenkende Abtastgeräte, z. B. für ein lineares Array. Bei längeren Verzögerungszeiten wirken die LC-Verzögerungsleitungen für höhere Frequenzen bandbegrenzend. Sie stellen also jeweils einen Tiefpass dar, dessen Eckfrequenz ca. 5 MHz betragen kann. Gleichzeitig gehen Bauteiltoleranzen in hohem Masse in die Genauigkeit der gesamten Verzögerung ein. Aus diesem Grund werden LC-Verzögerungsleitungen für Transducer- oder Wandlerfrequenzen generell nur bis ca. 3,5 MHz verwendet. Diese Technik wird auch als «Basisbandtechnik» bezeichnet.The prior art provides for setting the delay times with the aid of LC delay lines which are provided with setting taps. This relatively inexpensive solution is particularly suitable for short delay times, i.e. for non-pivoting scanning devices, e.g. B. for a linear array. With longer delay times, the LC delay lines have a band-limiting effect for higher frequencies. They each represent a low pass, the corner frequency of which can be approximately 5 MHz. At the same time, component tolerances largely affect the accuracy of the overall deceleration. For this reason, LC delay lines for transducer or converter frequencies are generally only used up to approx. 3.5 MHz. This technique is also called "baseband technique".

In der DE-OS 3004689 ist ein Empfangsverzögerungssystem zur Verwendung in einem Ultraschallabbildungssystem beschrieben, bei dem in jedem Kanal ein variables Vorverzögerungselement mit dem Wandler und einem Hauptverzögerungselement in Reihe geschaltet ist. In der Praxis werden die Vorverzögerungselemente hauptsächlich für die Feinabstimmung benutzt, d.h. um eine stufenweise Einstellung der Verzögerungsschritte zu ermöglichen, die normalerweise an den Hauptverzögerungselementen nicht durchgeführt werden kann. Diese Anordnung erlaubt es insbesondere, über einen verhältnismässig grossen Bereich möglicher Signalfrequenzen und unterschiedlichen Abständen zwischen den Wandlerelementen Signalkohärenz zu erzielen. Dazu benötigt diese Schaltungsanordnung jedoch eine hohe Anzahl von Verzögerungselementen.DE-OS 3004689 describes a reception delay system for use in an ultrasound imaging system, in which a variable pre-delay element is connected in series with the transducer and a main delay element in each channel. In practice, the pre-delay elements are mainly used for fine tuning, i.e. to allow a gradual adjustment of the delay steps that normally cannot be performed on the main delay elements. This arrangement makes it possible, in particular, to achieve signal coherence over a relatively large range of possible signal frequencies and different distances between the converter elements. For this purpose, however, this circuit arrangement requires a large number of delay elements.

Weiterhin ist in der DE-OS 2736310 eine Verzögerungsanordnung angegeben, bei der jeweils eine kleine, einstellbare Verzögerungsleitung zwischen den Messumformern oder Wandlern und den Anzapfungen einer Hauptverzögerungsleitung eingefügt ist. Diese Anzapfungen auf der Hauptverzögerungsleitung sind derart ausgewählt, dass die Anordnung längs eines gewünschten Abtastwinkels oder einer Abtastrichtung fokussiert wird. Dagegen werden die kleinen Verzögerungen während einer Abtastung in der besagten Richtung verändert, um die Fokussierung der Anordnung vom Minimalbereich zum Maximalbereich hin zu verändern. Da die ausgewählten Anzapfungen der Hauptverzögerungsleitung während der Abtastung in einer gewünschten Richtung nicht umgeschaltet werden, gibt das Schaltungsprinzip nur bei kleinen Aperturen ausreichend kohärente Signale.Furthermore, DE-OS 2736310 specifies a delay arrangement in which a small, adjustable delay line is inserted between the transmitters or converters and the taps of a main delay line. These taps on the main delay line are selected such that the array is focused along a desired scan angle or direction. On the other hand, the small delays are changed during a scan in said direction in order to change the focus of the arrangement from the minimum range to the maximum range. Since the selected taps of the main delay line are not switched over in a desired direction during the scanning, the circuit principle only gives sufficiently coherent signals with small apertures.

Höhere Transducerfrequenzen können mit Hilfe von LC-Verzögerungsleitungen durch Abwärtsmischen auf eine Zwischenfrequenz unter 3,5 MHz verarbeitet werden. Die Abwärtsmischtechnik setzt jedoch eine gleichbleibende Signalbandbreite und Sendepulslänge der einzelnen Wandlersignale voraus. Die zeitliche Sendepulslänge sollte aber im Interesse einer guten Auflösung beim Übergang zu hohen Transducerfrequenzen geändert, d. h. verringert werden.Higher transducer frequencies can be processed using LC delay lines by downmixing to an intermediate frequency below 3.5 MHz. However, downmixing technology requires a constant signal bandwidth and transmission pulse length for the individual converter signals. However, the temporal transmit pulse length should be changed in the interest of good resolution when transitioning to high transducer frequencies, i. H. be reduced.

Eine weitere Realisierungsmöglichkeit sieht die Oberflächenwellenfilter-Technik oder SAW-Filtertechnik (vgl. z. B. Ultrasonics, Vol. 17, pp. 225-229, Sept. 1979) vor. Hierzu ist es erforderlich, das Empfangssignal des einzelnen Ultraschallwandlerelements aufwärts zu mischen, um in das bei der SAW-Technik erforderliche hohe Frequenzband von 20-50 MHz zu kommen. Nach der Summation der einzelnen Empfangssignale des Phased-Arrays muss dann wieder abwärtsgemischt werden. Nachteile der SAW-Technik sind die Tatsache, dass in jedem Kanal Aufwärtsmischer eingesetzt werden müssen, was einen beträchtlichen Aufwand bedeutet, sowie die Schwierigkeit, eine genügend feine Abstufung der Verzögerungszeiten bei den SAW-Filtern zu erzielen.Another possible implementation provides surface wave filter technology or SAW filter technology (see, for example, Ultrasonics, Vol. 17, pp. 225-229, Sept. 1979). For this purpose, it is necessary to mix the received signal of the individual ultrasound transducer element upwards in order to get into the high frequency band of 20-50 MHz required in SAW technology. After the summation of the individual received signals of the phased array, it is then necessary to mix down again. Disadvantages of the SAW technology are the fact that up-mixers have to be used in each channel, which means a considerable outlay, and the difficulty in achieving a sufficiently fine gradation of the delay times in the SAW filters.

Aufwärts- und Abwärtsmischungen im Zusammenhang mit einem Phased-Array-Gerät sind z. B. aus Fig. 11 der DE-PS 2854134 bekannt. Eine digitale Verzögerungstechnik bei einem Phased-Array-Gerät wird in der EP-PS 0027618, insbesondere bei Fig. 1 und 2, beschrieben.Up and down mixes associated with a phased array device are e.g. B. from Fig. 11 of DE-PS 2854134 known. A digital delay technique in a phased array device is described in EP-PS 0027618, in particular in FIGS. 1 and 2.

Bei der Konzeption eines Phased-Array-Gerätes sind auch folgende Gesichtspunkte zu berücksichtigen:

  • Nimmt man z.B. bei einer medizinischen Untersuchung eine Mittenfrequenz des Empfangsspektrums von fs=3,5 MHz an und berücksichtigt man theoretisch eine Bandbreite Δf=fs (2λ-PuIs), so erhält man als Maximalfrequenz fsmax=fs+Δf/ 2=1,5 fs=5,25 MHz. Daraus resultiert nach dem bekannten Abtasttherorem von Shannon eine Abtastfrequenz für das einzelne Ultraschall-Wandlerelement von fa > 2 fsmax=3 fs=10,5 MHz. Diese Abtastfrequenz fa ist also die minimale Frequenz, um das einzelne Signal eines Wandlerelementes rekonstruieren zu können.
When designing a phased array device, the following aspects must also be taken into account:
  • Assuming, for example, in a medical examination a center frequency of the reception spectrum of f s = 3.5 MHz and theoretically considering a bandwidth Δf = f s (2λ-PuIs), the maximum frequency obtained is f smax = f s + Δf / 2 = 1.5 f s = 5.25 MHz. According to the well-known Shannon sampling theorem, this results in a sampling frequency for the individual ultrasound transducer element of f a > 2 f smax = 3 f s = 10.5 MHz. This sampling frequency f a is therefore the minimum frequency in order to be able to reconstruct the individual signal of a converter element.

Für die Quantisierung der Phase, d. h. eine ausreichende Genauigkeit der Zeitverzögerung zwischen zwei benachbarten Wandlerelementen, ist eine Abtastung mit mindestens 1/8 der Wellenlänge erforderlich. Dies ergibt eine quantisierte Phasenverschiebung innerhalb der Wellenlänge λ von 360°/8=45° oder (±22,5°). Bei einer Mittenfrequenz fs=3,5 MHz erhält man damit eine Zeitverzögerung von 35,7 nsec, d.h. ±17,9 nsec. Diese Phasen- oder Zeitgenauigkeit erfordert eine Abtastfrequenz fa > 28 MHz, wenn das Signal digital weiterverarbeitet werden soll (EP-PS 0027618). Diese hohe Abtastfrequenz fa setzt heutzutage den Einsatz von ECL-Bausteinen voraus und führt zu einem relativ teueren Phased-Array-Gerät.For the quantization of the phase, ie a sufficient accuracy of the time delay between rule two adjacent transducer elements, one sample with at least 1/8 of the wavelength is required. This results in a quantized phase shift within the wavelength λ of 360 ° / 8 = 45 ° or (± 22.5 °). With a center frequency f s = 3.5 MHz, a time delay of 35.7 nsec is obtained, ie ± 17.9 nsec. This phase or time accuracy requires a sampling frequency f a > 28 MHz if the signal is to be digitally processed (EP-PS 0027618). This high sampling frequency f a nowadays requires the use of ECL modules and leads to a relatively expensive phased array device.

Ein Ausweg aus diesem Geschwindigkeitsproblem ist die Quadraturtechnik (vgl. DE-PS 2854134, Fig. 8), bei der zwei Verzögerungskanäle zum Einsatz kommen, deren Signale um 90° phasenverschoben sind. Hier liegt die minimale Abtastfrequenz bei fg= 10,5 MHz. Dies lässt einen Einsatz von energiesparenden Techniken (z. B. HCMOS, Low Power Schottky)zu. Die Quadraturtechnik erfordert aber einen relativ hohen Aufwand, da jeweils zwei Kanäle pro Wandlerelement für die Signalverarbeitung benötigt werden.One way out of this speed problem is quadrature technology (cf. DE-PS 2854134, Fig. 8), in which two delay channels are used, the signals of which are phase-shifted by 90 °. Here the minimum sampling frequency is fg = 10.5 MHz. This allows the use of energy-saving techniques (e.g. HCMOS, Low Power Schottky). Quadrature technology, however, requires a relatively high level of effort, since two channels per converter element are required for signal processing.

Ziel der Erfindung ist die Schaffung eines Phased-Array-Gerätes, das eine hohe Genauigkeit bei der Einstellung des Steuerwinkels ermöglicht und dennoch nur einen vergleichsweise geringen Aufwand erfordert.The aim of the invention is to create a phased array device which enables a high degree of accuracy in the adjustment of the control angle and yet only requires a comparatively small outlay.

Diese Aufgabe wird erfindungsgemäss nach einer ersten grundlegenden Ausführungsform gemäss Patentanspruch 1 gelöst. Hierbei ist es also möglich, mehrere benachbarte Kanäle, z. B. 4, für die Signalverarbeitung zusammenzufassen.According to the invention, this object is achieved according to a first basic embodiment according to patent claim 1. It is therefore possible to use several adjacent channels, e.g. B. 4 to summarize for signal processing.

Diese Aufgabe wird erfindungsgemäss nach einer zweiten grundlegenden Ausführungsform gemäss Patentanspruch 5 gelöst.According to the invention, this object is achieved according to a second basic embodiment according to patent claim 5.

Als Vorteil der Erfindung wird es angesehen, dass der jeweilige Steuerwinkel wegen der Verwendung von Bausteinen mit festen bausteinspezifischen Verzögerungszeiten (Toleranzen) und der digitalen Speicher, speziell einiger Schieberegister, sehr genau eingestellt werden kann. Ein Driften der Verzögerung auch nach längerem Einsatz des Phased-Array-Gerätes ist nicht zu befürchten. Infolge der hohen Genauigkeit bei der Einstellung des Steuerwinkels ergibt sich auch eine hohe Genauigkeit bei der Fokussierung und damit ein hohes Auflösungsvermögen. Dies ist von besonderem Interesse bei Anwendung der mitlaufenden Fokussierung im Empfangsfalle.It is considered an advantage of the invention that the respective control angle can be set very precisely because of the use of components with fixed component-specific delay times (tolerances) and the digital memory, especially some shift registers. There is no fear of the delay drifting even after the phased array device has been used for a long time. As a result of the high accuracy in the setting of the control angle, there is also a high level of accuracy in the focusing and thus a high resolving power. This is of particular interest when using concurrent focusing in the case of reception.

Ausführungsbeispiele der Erfindung sind in drei Figuren dargestellt und werden im folgenden näher erläutert. Es zeigen:

  • Fig. 1 eine erste Ausführungsform, bei der sowohl von einer analogen als auch von einer digitalen Verzögerung Gebrauch gemacht wird;
  • Fig. 2 eine zweite Ausführungsform, die gegenüber der Ausführungsform nach Figur 1 vereinfacht aufgebaut ist; und
  • Fig. 3 eine dritte Ausführungsform, die auf einem voll digitalen Verzögerungskonzept beruht.
Embodiments of the invention are shown in three figures and are explained in more detail below. Show it:
  • 1 shows a first embodiment in which use is made of both an analog and a digital delay;
  • Fig. 2 shows a second embodiment, which is simplified compared to the embodiment of Figure 1; and
  • Fig. 3 shows a third embodiment, which is based on a fully digital delay concept.

Das Phased-Array-Gerät nach Figur 1, das insbesondere für medizinische Bilddarstellungen herangezogen wird, besteht aus einer Vielzahl von einzelnen Ultraschallwandler-Elementen E1, E2,... E64, die sowohl für die Emission als auch für den Empfang von Ultraschall-Signalen herangezogen werden. In Figur 1 ist lediglich der Empfangsteil des Phased-Array-Geräts dargestellt. In einem solchen Gerät müssen die empfangenen Ultraschall-Signale mit der eingangs beschriebenen hohen Genauigkeit verzögert werden. Zur Vermeidung von Antennen-Gitterstörungen (grating lobes) und zur Erzielung einer ausreichenden Auflösung sollte die Anzahl der Ultraschallwandler-Elemente gross gewählt werden. Als günstiger Kompromiss bietet sich vorliegend die Zahl 64 bei einem Elementeabstand von λ/2 an.The phased array device according to FIG. 1, which is used in particular for medical imaging, consists of a large number of individual ultrasound transducer elements E1, E2,... E64, which are used both for the emission and for the reception of ultrasound signals be used. In Figure 1, only the receiving part of the phased array device is shown. In such a device, the received ultrasound signals must be delayed with the high accuracy described above. To avoid antenna grating interference (grating lobes) and to achieve sufficient resolution, the number of ultrasonic transducer elements should be large. In the present case, the number 64 with an element spacing of λ / 2 is a good compromise.

Um den Aufwand gering zu halten, der bei einem Einsatz eines Verzögerungskonzepts mit der oben angegebenen Phasengenauigkeit entstehen würde, ist nach Figur 1 vorgesehen, dass die empfangenen Ultraschall-Signale mit einer kurzen und mit einer langen Verzögerung versehen werden. Hierdurch ist es möglich, benachbarte Signalverarbeitungskanäle zusammenzufassen. Wie später deutlich wird, sind in Figur 1 jeweils 4 Kanäle zusammengefasst.In order to keep the effort low, which would result from using a delay concept with the phase accuracy specified above, it is provided according to FIG. 1 that the received ultrasound signals are provided with a short and a long delay. This makes it possible to combine adjacent signal processing channels. As will become clear later, 4 channels are combined in FIG. 1.

Nach Figur 1 enthält das Gerät eine gemischte Verzögerungstechnik, nämlich eine analoge Vorverzögerung und eine digitale Hauptverzögerung. Es handelt sich also um eine hybride Lösung. Die analoge Vorverzögerung ist eine Feinverzögerung. Sie spielt sich in einem Bereich ab, der mit X bezeichnet ist. In diesem Bereich X sind insgesamt 64 Kanäle vorgesehen. Die Feinverzögerung findet dabei zwischen 0 und 2λ statt. Dem Bereich X schliesst sich ein Bereich Y an, der nur noch 16 Kanäle umfasst. In diesem Bereich Y sind tiefenabhängig regelbare Verstärker untergebracht. Dem Bereich Y schliesst sich ein Bereich Z an, der ebenfalls 16 Kanäle umfasst. Hier findet eine Langzeitverzögerung statt.According to FIG. 1, the device contains a mixed delay technique, namely an analog pre-delay and a digital main delay. So it's a hybrid solution. The analog pre-delay is a fine delay. It takes place in an area labeled X. A total of 64 channels are provided in this area X. The fine deceleration takes place between 0 and 2λ. Area X is followed by area Y, which only comprises 16 channels. In this area Y there are amplifiers that can be controlled as a function of depth. Area Y is followed by area Z, which also comprises 16 channels. There is a long-term delay here.

Experimente haben gezeigt, dass bei medizinischen Untersuchungen mit einem elektronischen Sektor-Scanner Gesamt-Verzögerungszeiten erforderlich sind, die im Bereich von 6 bis 12 µsec liegen. Im vorliegenden Fall übernimmt bei Zugrundelegung dieser Werte die Feinverzögerung im Bereich X eine Verzögerung von 0 bis 600 nsec, und die Grobverzögerung im Bereich Z übernimmt eine Verzögerung zwischen 5,4 und 11,4 jisec.Experiments have shown that medical examinations with an electronic sector scanner require total delay times which are in the range from 6 to 12 µsec. In the present case, based on these values, the fine deceleration in area X assumes a delay of 0 to 600 nsec, and the coarse deceleration in area Z assumes a deceleration between 5.4 and 11.4 jisec.

Nach Figur 1 ist jedem Ultraschallwandler-Element E1 bis E64 ein Vorverstärker V1 bis V64 mit fester Verstärkung nachgeschaltet. Diesen Vorverstärkern V1 bis V64 ist wiederum jeweils ein Multiplexer M1 bis M64 nachgeschaltet. Der jeweilige Multiplexer M kann von einer Steuerungseinrichtung C mit Taktimpulsen beaufschlagt werden, was durch einen Pfeil am jeweiligen Block M1 bis M64 gekennzeichnet ist. Den Multiplexern M1 bis M64 ist jeweils ein analoges Vorverzögerungsglied T1 bis T64 zugeordnet. Dessen Verzögerungszeit, insbesondere im Bereich von 0 bis 600 nsec, kann mit Hilfe des zugehörigen Multiplexers M1 bis M64 eingestellt werden. Bei den Vorverzögerungsgliedern T1 bis T64 kann es sich insbesondere um LC-Leitungen mit einer Anzahl von Abgriffen, z. B. mit 16 Abgriffen, handeln. Bei solchen LC-Leitungen ergibt sich eine Verzögerung, die für die vorliegenden Zwekke genau genug ist.According to FIG. 1, each ultrasound transducer element E1 to E64 is followed by a preamplifier V1 to V64 with a fixed gain. A multiplexer M1 to M64 is in turn connected downstream of these preamplifiers V1 to V64. The respective multiplexer M can be supplied with clock pulses by a control device C, which is indicated by an arrow on the respective block M1 to M64. The multiplexers M1 to M64 are each analog Predelay element T1 to T64 assigned. Its delay time, in particular in the range from 0 to 600 nsec, can be set using the associated multiplexer M1 to M64. The pre-delay elements T1 to T64 can in particular be LC lines with a number of taps, e.g. B. with 16 taps. With such LC lines there is a delay which is precise enough for the purposes at hand.

Mit Hilfe der Multiplexer M1 bis M64 ist somit die Feinverzögerung dynamisch, d.h. während des Empfangs einer jeden Ultraschallzeile, umschaltbar. Auf diese Weise lässt sich eine dynamische Fokussierung erreichen.With the help of the multiplexers M1 to M64, the fine deceleration is dynamic, i.e. switchable while receiving each ultrasound line. In this way, dynamic focusing can be achieved.

Die Signalverarbeitung von jeweils vier benachbarten Ultraschallelementen E1 bis E64 ist im vorliegenden Fall zusammengefasst. Zu diesem Zweck sind beispielsweise die Verzögerungsglieder T1 bis T4 an ein gemeinsames Summierglied S1 angeschlossen. Entsprechend sind z. B. auch die Verzögerungsglieder T61 bis T64 an ein gemeinsames Summierglied S16 angeschlossen. Die Feinverzögerung umfasst dabei, wie angegeben, die Zeitdauer von mindestens 2λ, um jeweils vier solcher Nachbarelemente zusammenfassen zu können. Der Wert 2λ ist dabei eine empirisch gefundene Grösse. Sie stellt einen Kompromiss dar, der bei den meisten Ultraschall-Applikatoren nach dem Phased-Array-Prinzip anwendbar ist. Anstelle von vier Kanälen könnten im übrigen auch zwei, sechs oder aber acht Kanäle jeweils zusammengefasst sein. Nach der Summation der Signale von jeweils vier Nachbarkanälen in den Summiergliedern S1 bis S16 wird das so gewonnene zusammengefasste Empfangssignal jeweils mit Hilfe von regelbaren Verstärkern TGC1 bis TGC16 tiefenabhängig verstärkt, um anschliessend die A/D-Wandler-Dynamik nutzen zu können.The signal processing of four adjacent ultrasonic elements E1 to E64 is summarized in the present case. For this purpose, the delay elements T1 to T4 are connected to a common summing element S1, for example. Accordingly, z. B. also the delay elements T61 to T64 connected to a common summing element S16. As stated, the fine delay comprises the time period of at least 2λ in order to be able to combine four such neighboring elements. The value 2λ is an empirically found variable. It represents a compromise that can be applied to most ultrasound applicators based on the phased array principle. Instead of four channels, two, six or eight channels could be combined. After the summation of the signals from four adjacent channels in the summers S1 to S16, the combined received signal obtained in this way is amplified depending on the depth with the aid of controllable amplifiers TGC1 to TGC16, in order to then be able to use the A / D converter dynamics.

Nach der Verstärkung in den Verstärkern TGC1 bis TGC16 ergeben sich zwei Realisierungsmöglichkeiten, die in den Figuren 1 und 2 getrennt dargestellt sind. Nach Figur 1 wird das Empfangssignal im Quadraturverfahren, d.h. in komplexer Form, abgetastet. Hierdurch bleibt die Phasengenauigkeit der gesamten Verzögerungseinheit konstant, z. B. λ/12, wenn faq =fa ist (faq = Quadraturverfahren-Abtastfrequenz).After the amplification in the amplifiers TGC1 to TGC16, there are two implementation options, which are shown separately in FIGS. 1 and 2. According to FIG. 1, the received signal is sampled using the quadrature method, ie in complex form. As a result, the phase accuracy of the entire delay unit remains constant, for. B. λ / 12 if f a q = f a (faq = quadrature method sampling frequency).

Im einzelnen wird nach Figur 1 das Ausgangssignal des Verstärkers TGC1 einem Verzögerungsglied zugeführt, welches aus einem Speicher N1 und zwei diesem vorgeschalteten Analog-Digital-Wandlem W1-1 und W1-2 besteht. Der erste Wandler W1-1 ist mit einer Taktfrequenz f beaufschlagt, die beispielsweise der eingangs genannten Abtastfrequenz fa=10,5 MHz gleich ist. Der zweite Wandler W1-2 wird mit derselben Taktfrequenz getaktet, jedoch ist das Taktsignal gegenüber demjenigen des ersten Wandlers W1-1 um 90° verschoben. Dies wird dadurch zum Ausdruck gebracht, dass die Taktfrequenzen mit f(ϕ=0°) bzw. f(cp=90°) bezeichnet sind. Die beiden Wandler W1-1, W1-2 bewirken eine Zerlegung des Empfangssignals in einen Real- und einen Imaginärteil. Der WandIer W1-1 erzeugt dabei den In-Phase-Term oder Kosinus-Anteil, während der Wandler W1-2 den Quadratur-Term oder Sinus-Anteil bereitstellt. Der nachgeschaltete Speicher N1 ist vorzugsweise ein Schieberegister. Dieses wird z. B. in λ/8-Schritten abgetastet, wozu ihm von der Steuereinrichtung C entsprechende Steuerimpulse zugeführt werden.1, the output signal of the amplifier TGC1 is fed to a delay element which consists of a memory N1 and two analog-digital converters W1-1 and W1-2 connected upstream of it. A clock frequency f is applied to the first converter W1-1, which is, for example, the sampling frequency f a = 10.5 MHz mentioned at the beginning. The second converter W1-2 is clocked at the same clock frequency, but the clock signal is shifted by 90 ° with respect to that of the first converter W1-1. This is expressed in that the clock frequencies are designated with f (ϕ = 0 °) or f (cp = 90 °). The two converters W1-1, W1-2 break down the received signal into a real and an imaginary part. The converter W1-1 generates the in-phase term or cosine component, while the converter W1-2 provides the quadrature term or sine component. The downstream memory N1 is preferably a shift register. This is e.g. B. scanned in λ / 8 steps, for which purpose it is supplied by the control device C corresponding control pulses.

Die Grobverzögerungsglieder, die den weiteren Verstärkern TGC2 bis TGC16 nachgeschaltet sind, sind entsprechend aufgebaut. Insgesamt sind also 16 Speicher N1 bis N16 vorhanden. Diese sind ausgangseitig gemeinsam an ein Addierglied A angeschlossen. Die Speicher N1 bis N16, in Zusammenarbeit mit den vorgeschalteten Analog-Digital-Wandlern W1-1 bis W16-2, dienen somit zur Langzeitverzögerung. Mit ihrer Hilfe lässt sich insbesondere der Schwenk- oder der Ablenkwinkel bei einem Phased-Array-Gerät einstellen.The coarse delay elements, which are connected downstream of the further amplifiers TGC2 to TGC16, are constructed accordingly. There are a total of 16 memories N1 to N16. On the output side, these are jointly connected to an adder A. The memories N1 to N16, in cooperation with the upstream analog-digital converters W1-1 to W16-2, are used for long-term delays. With their help, the pivoting or deflection angle in particular can be set in a phased array device.

Das Ausgangssignal des Addiergliedes A besteht aus einem imaginären Anteil i und einem reellen Anteil q, ist also komplex. Aus diesen beiden Anteilen i und q lässt sich nach der Beziehung √i2 + q2 der Betrag des Signals bilden, der auf einem Bildschirm dargestellt werden kann.The output signal of the adder A consists of an imaginary part i and a real part q, so it is complex. From these two parts i and q, the magnitude of the signal can be formed according to the relationship √i 2 + q 2 , which can be displayed on a screen.

Die Ausführungsform von Figur 2 entspricht weitgehend derjenigen von Figur 1. Jedoch sind im vorliegenden Fall die zweiten Verzögerungsglieder anders, d.h. einfacher aufgebaut. Diese vereinfachte Ausführungsform lässt somit eine gewisse Welligkeit zu, wobei anzumerken ist, dass diese für die Bildqualität unerheblich ist. Im Unterschied zu Figur 1 wird das zusammengefasste Empfangssignal nicht im Quadraturverfahren, sondern jeweils einkanalig abgetastet. In jedem Kanal ist zu diesem Zweck eine Hintereinanderschaltung von einem Analog-Digital-Wandler W1 bis W16 mit einem von einer Steuereinrichtung C, gesteuerten Speicher N1 bis N16 vorhanden. Der Analog-Digital-Wandler W1 bis W16 wird von der Steuereinrichtung C' jeweils mit einer Abtastfrequenz f beaufschlagt. Diese ist bevorzugt etwas höher als der zuvor angegebene Wert von 10,5 MHz. Theoretische Untersuchungen haben ergeben, dass die Abtastfrequenz f aber unter 20 MHz liegen kann. Die Phasengenauigkeit der digitalen Kette wird von der Abtastfrequenz f bestimmt. Bei einer Abtastfrequenz f=20 MHz erhält man beispielsweise eine Phasengenauigkeit von X/5.The embodiment of Figure 2 largely corresponds to that of Figure 1. However, in the present case the second delay elements are different, i.e. more simply constructed. This simplified embodiment thus allows a certain ripple, it being noted that this is irrelevant for the image quality. In contrast to FIG. 1, the combined received signal is not sampled using the quadrature method, but rather in one channel. For this purpose, each channel has a series connection of an analog-digital converter W1 to W16 with a memory N1 to N16 controlled by a control device C. The analog-to-digital converter W1 to W16 is each subjected to a sampling frequency f by the control device C '. This is preferably somewhat higher than the previously stated value of 10.5 MHz. Theoretical studies have shown that the sampling frequency f can be below 20 MHz. The phase accuracy of the digital chain is determined by the sampling frequency f. With a sampling frequency f = 20 MHz, for example, a phase accuracy of X / 5 is obtained.

Nach der Literaturstelle G.F. Manez: «Design of a simplified delayed system for ultrasound phased array imaging» in IEEE Transactions on Sonics and Ultrasonics, Vol. SU-30, No. 6, Seite 350f, genügt bei den einzelnen Verzögerungsgliedern W1, N1 bis W16, N16 eine gröbere Quantisierung der Verzögerung, wenn der Träger hinreichend genau durch eine Feinverzögerung verzögert wird. Dies ist vorliegend durch die Feinverzögerung im Bereich X der Fall.According to the G.F. Manez: "Design of a simplified delayed system for ultrasound phased array imaging" in IEEE Transactions on Sonics and Ultrasonics, Vol. SU-30, No. 6, page 350f, a coarser quantization of the delay is sufficient for the individual delay elements W1, N1 to W16, N16 if the carrier is decelerated sufficiently precisely by a fine delay. This is the case here due to the fine deceleration in area X.

Am Ausgang des den Verzögerungsgliedern W1, N1 bis W16, N16 nachgeschalteten Addiergliedes AG ergibt sich automatisch ein Betragssignal s, das dem Wert s = V i2 + q2 in Figur 1 entspricht.At the output of the adder AG connected downstream of the delay elements W1, N1 to W16, N16, an amount automatically results signal s, which corresponds to the value s = V i2 + q2 in Figure 1.

Figur 3 zeigt eine voll digitalisierte Realisierungsform des Verzögerungskonzepts für ein Phased-Array-Gerät, bei dem die Verzögerung wiederum in eine Feinverzögerung (siehe Bereich X) und in eine Grobverzögerung (siehe Bereich Z) unterteilt ist. Im Bereich X der Feinverzögerung sind wiederum im vorliegenden Ausführungsbeispiel 64 Kanäle vorgesehen, während im darauffolgenden Grobverzögerungsbereich Z nur 16 Verarbeitungskanäle vorgesehen sind.FIG. 3 shows a fully digitized implementation of the delay concept for a phased array device, in which the delay is again divided into a fine delay (see area X) and a coarse delay (see area Z). In the exemplary embodiment, 64 channels are again provided in area X of the fine delay, while only 16 processing channels are provided in the subsequent coarse delay area Z.

Nach Figur 3 ist den 64 Ultraschallwandler-Elementen E1 bis E64 (bei ausschliesslich digitaler Realisierung der Verzögerung) jeweils ein Tiefenausgleichsverstärker TV1 bis TV64 nachgeschaltet. Diese Tiefenausgleichsverstärker sind regelbar und entsprechen den Verstärkern TGC1 bis TGC16 der Figuren 1 und 2. Somit wird das Empfangssignal eines jeden Elements E1 bis E64 tiefenabhängig verstärkt. Es wird anschliessend mit Hilfe eines Analog-Digital-Wandlers AD1 bis AD64 digitalisiert. Diese Analog-Digital-Wandler AD1 bis AD64 werden vorliegend mit einer höheren Frequenz betrieben als diejenigen in den Figuren 1 und 2, beispielsweise mit einer Frequenz f von 28 MHz, um mit λ/8 arbeiten zu können. Eine so hohe Frequenz bedeutet allerdings, dass die Bauelemente in ECL-Technik ausgelegt sein sollten. Vorliegend wird also angenommen, dass die A/D-Wandlung mit relativ hoher Abtastfrequenz f', die auch grösser als 28 MHz sein kann, durchgeführt wird. Abweichend davon kann sie aber auch, was in Figur 3 nicht gezeigt ist, nach dem Quadraturverfahren ausgeführt werden.According to FIG. 3, the 64 ultrasound transducer elements E1 to E64 (in the case of exclusively digital implementation of the delay) are each followed by a depth compensation amplifier TV1 to TV64. These depth compensation amplifiers can be regulated and correspond to the amplifiers TGC1 to TGC16 of FIGS. 1 and 2. Thus the received signal of each element E1 to E64 is amplified depending on the depth. It is then digitized using an analog-to-digital converter AD1 to AD64. In the present case, these analog-digital converters AD1 to AD64 are operated at a higher frequency than those in FIGS. 1 and 2, for example at a frequency f of 28 MHz, in order to be able to work with λ / 8. However, such a high frequency means that the components should be designed using ECL technology. It is assumed in the present case that the A / D conversion is carried out with a relatively high sampling frequency f ', which can also be greater than 28 MHz. In deviation from this, it can also be carried out according to the quadrature method, which is not shown in FIG. 3.

Zur Reduzierung des Aufwandes an digitalen Elementen, insbesondere an Busleitungen, wird bei der vorliegenden rein digitalen Lösung eine Aufteilung in eine Feinverzögerung mit Hilfe von 64 Schieberegistern VL1 bis VL64 und in eine Grobverzögerung mit Hilfe von 16 Schieberegistern VR1 bis VR16 vorgenommen. Die genannten Schieberegister VL1 bis VL64 und VR1 bis VR16 sind insbesondere Schieberegister mit variabler Länge. Dabei kann beispielsweise jedes der Schieberegister VL1 bis VL64 insgesamt 16 Stufen umfassen, während jedes der Schieberegister VR1 bis VR16 ein Vierfaches dieser 16 Stufen beinhaltet. Mit anderen Worten, in beiden Schieberegisterarten können dieselben Grundbausteine verwendet werden.In order to reduce the expenditure on digital elements, in particular on bus lines, the present purely digital solution is divided into a fine delay using 64 shift registers VL1 to VL64 and a coarse delay using 16 shift registers VR1 to VR16. The shift registers VL1 to VL64 and VR1 to VR16 are, in particular, shift registers with a variable length. For example, each of the shift registers VL1 to VL64 can comprise a total of 16 stages, while each of the shift registers VR1 to VR16 contains four times these 16 stages. In other words, the same basic building blocks can be used in both types of shift registers.

Die Schieberegister VL1 bis VL64 entsprechen in ihrer Funktion einer Kombination der Multiplexer M1 bis M64 und der Zeitverzögerungsglieder T1 bis T64 von Figur 1. Der Ausgang von vier solcher Schieberegister, z. B. VL1 bis VL4, die jeweils zu benachbarten Ultraschallwandler-Elementen, z. B. E1 bis E4 gehören, sind jeweils gemeinsam an ein Summierglied S1 bis S16 angeschlossen. Anstelle einer Zusammenfassung von jeweils vier Kanälen kann auch eine andere Anzahl, z.B. eine Zahl von 8 Kanälen, gewählt sein. Die Verzögerungszeiten der einzelnen Schieberegister VL1 bis VL64 können während des Empfangs einer Ultraschallzeile rechnergesteuert verändert werden, insbesondere um eine dynamische Fokussierung zu erzielen. Zu diesem Zweck sind ihre Steuereingänge mit einer Steuereinrichtung C" verbunden.The shift registers VL1 to VL64 correspond in their function to a combination of the multiplexers M1 to M64 and the time delay elements T1 to T64 from FIG. 1. The output of four such shift registers, e.g. B. VL1 to VL4, each to adjacent ultrasonic transducer elements, for. B. E1 to E4, are each connected together to a summing element S1 to S16. Instead of a combination of four channels each, a different number, e.g. a number of 8 channels. The delay times of the individual shift registers VL1 to VL64 can be changed under computer control during the reception of an ultrasound line, in particular in order to achieve dynamic focusing. For this purpose, their control inputs are connected to a control device C ".

Es ist also festzuhalten, dass mit Hilfe von Summiergliedern S1 bis S16 auch hier jeweils eine vorgegebene Anzahl von Datenkanälen zusammengefasst wird.It should therefore be noted that a predetermined number of data channels is also combined here in each case with the aid of summing elements S1 to S16.

Die Ausgänge der einzelnen Summierglieder S1 bis S16 sind jeweils über ein zugeordnetes Schieberegister VR1 bis VR16, die die längere der beiden Verzögerungen bewirken, mit einem Additionsglied AGL verbunden. Dieses summiert die einzelnen zusammengefassten und verzögerten Signale auf. An seinem Ausgang entsteht ein Ausgangssignal s', das gegenüber demjenigen von Figur 1 und 2 hochfrequent ist. Dieses hochfrequente Ausgangssignal s' entspricht dem Betrag und kann für Bilddarstellung verwendet werden. Aus diesem hochfrequenten Ausgangssignal s' könnte man aber auch die beiden Signalanteile i und q ableiten.The outputs of the individual summing elements S1 to S16 are each connected to an addition element AGL via an assigned shift register VR1 to VR16, which bring about the longer of the two delays. This sums up the individual summarized and delayed signals. At its output there is an output signal s' which is high-frequency compared to that of FIGS. 1 and 2. This high-frequency output signal s' corresponds to the amount and can be used for image display. However, the two signal components i and q could also be derived from this high-frequency output signal s'.

Auch bei der Ausführungsform nach Figur 3 ergibt sich eine präzise Einstellung und Steuerung der Verzögerung. Auch hier kann der Schwenk wieder über die dem Addierglied AGL unmittelbar vorgeschalteten Verzögerungsglieder für die Grobverzögerung, d.h. die Schieberegister VR1 bis VR16, eingestellt werden.The embodiment according to FIG. 3 also results in precise setting and control of the delay. Here, too, the swivel can again be effected via the delay elements for the coarse deceleration, which are immediately upstream of the adder AGL. the shift registers VR1 to VR16 can be set.

Claims (9)

1. Phased-array-device for the ultrasonic scanning of an object having a number of ultrasonic transducer elements, with which there are associated delay members at least for the receiving case, having the following features:
the ultrasonic transducer elements (E1 to E64) are connected to first delay members (M1, T1 to M64, T64) for the analog fine delay of the received signals; in each case a given number of first delay members (M1, T1 to M64, T64) for adjacent ultrasonic transducer elements (E1 to E64) are connected with a common summing element (S1 toS6);
the output signals of the summing elements (S1 to S16) are supplied to two delay members (W1-1, W1-2, N1 to W16-1, W16-2, N16; W7, N1 to W16, N16) for the digital coarse delay;
and the output signals emitted from the second delay members (W1-1, W1-2, N1 to W16-1, W16-2, N16; W1, N1 to W16, N16) are supplied to a digital adding element (A; AG), at the output of which there is emitted a summation signal (i, q; s) which is provided for the image representation (Figures 1 and 2).
2. Phased-array-device according to claim 1, characterised in that provided as first delay members there are, in each case, a multiplexer (M1 to M64) and an LC-line (T1 to T64) controlled by the latter (Figures 1 and 2).
3. Phased-array-device according to claim 1 or 2, characterised in that provided as second delay members there is, in each case, a memory (N1 to N16) to which there are previously connected two analog digital transducers (W1-1, W1-2 to W16-1, W16-2) which are controlled with clock signals of given frequency [f(ϕ=0°), f(ϕ=90°)], which are phase-shifted in respect of each other by 90° (Figure 1).
4. Phased-array-device according to claim 1 or 2, characterised in that provided as second delay members, there is, in each case, a memory (N1 to N16), to which there is previously connected an analog digital transducer (W1 to W16) which is controlled with clock signals of given scanning frequency (f≥fa) (Figure 2).
5. Phased-array-device for the ultrasonic scanning of an object having a number of ultrasonic transducer elements, with which there are associated delay members at least for the receiving case, having the following features:
a TGC amplifier (TV1 to TV64) and an analog digital transducer module (AD1 to AD64) are subsequently connected, in each case, to the ultrasonic transducer elements (E1 to E64);
a first delay component (VL1 to VL64) for the digital fine delay of the received signals is subsequently connected, in each case, to the analog digital transducer modules (AD1 to AD64);
in each case, a given number of these delay members (VL1 to VL64) for adjacent ultrasonic transducer elements (E1 to E64) are jointly connected to a summing element (S1 to S16);
and the individual summing elements (S1 to S16) are connected, by way of, in each case, a second delay component (VR1 to VR16), to a common adding element (AGL), the output signals (s' ) of which is provided for the image representation (Figure 3).
6. Phased-array-device according to claim 5, characterised in that the analog digital transducer module (AD1 to AD64) is an analog digital transducer which is scanned with high scanning frequency (f') (Figure 3).
7. Phased-array-device according to claim 5, characterised in that the analog digital transducer module (AD1 to AD64) is a module according to the quadratur method.
8. Phased-array-device according to claim 5, characterised in that the delay component (VL1 to VL64, VR1 to VR16) is a shift register with variable length (Figure 3).
9. Phased-array-device according to one of the claims 1 to 4, characterised in that the fine delay corresponds to at least a time period of 2 λ, where λ is the wavelength of the ultrasound in the scanned object.
EP85108128A 1984-07-12 1985-07-01 Phased-array apparatus Expired EP0170072B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85108128T ATE46783T1 (en) 1984-07-12 1985-07-01 PHASED ARRAY DEVICE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843425705 DE3425705A1 (en) 1984-07-12 1984-07-12 PHASED ARRAY DEVICE
DE3425705 1984-07-12

Publications (2)

Publication Number Publication Date
EP0170072A1 EP0170072A1 (en) 1986-02-05
EP0170072B1 true EP0170072B1 (en) 1989-09-27

Family

ID=6240486

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85108128A Expired EP0170072B1 (en) 1984-07-12 1985-07-01 Phased-array apparatus

Country Status (5)

Country Link
US (1) US4829491A (en)
EP (1) EP0170072B1 (en)
JP (1) JPH0778492B2 (en)
AT (1) ATE46783T1 (en)
DE (2) DE3425705A1 (en)

Families Citing this family (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1232059A (en) * 1985-03-21 1988-01-26 Donald C. Knudsen Digital delay generator for sonar and radar beam formers
DE8812400U1 (en) * 1988-09-30 1989-04-06 Siemens AG, 1000 Berlin und 8000 München Combined ultrasound imager and Doppler device
DE3920705A1 (en) * 1989-06-24 1991-01-10 Honeywell Elac Nautik Gmbh Digital processor displaying direction data from acoustic receivers - uses arrangement of summing modules to capture and process data for capture and process data for overall summing module
US5229933A (en) * 1989-11-28 1993-07-20 Hewlett-Packard Company 2-d phased array ultrasound imaging system with distributed phasing
US5263004A (en) * 1990-04-11 1993-11-16 Hewlett-Packard Company Acoustic image acquisition using an acoustic receiving array with variable time delay
US5269307A (en) * 1992-01-31 1993-12-14 Tetrad Corporation Medical ultrasonic imaging system with dynamic focusing
DE4223676C2 (en) * 1992-07-17 1997-06-12 Siemens Ag Method for the adaptive spatial filtering of a desired signal and for the suppression of interfering signals when receiving radio signals
US5436872A (en) * 1994-06-27 1995-07-25 Westinghouse Elec Corp Time delay-phase shift combination beamformer
US5928152A (en) * 1994-08-05 1999-07-27 Acuson Corporation Method and apparatus for a baseband processor of a receive beamformer system
US5793701A (en) * 1995-04-07 1998-08-11 Acuson Corporation Method and apparatus for coherent image formation
US5685308A (en) * 1994-08-05 1997-11-11 Acuson Corporation Method and apparatus for receive beamformer system
US6029116A (en) * 1994-08-05 2000-02-22 Acuson Corporation Method and apparatus for a baseband processor of a receive beamformer system
US5573001A (en) * 1995-09-08 1996-11-12 Acuson Corporation Ultrasonic receive beamformer with phased sub-arrays
US6128958A (en) * 1997-09-11 2000-10-10 The Regents Of The University Of Michigan Phased array system architecture
KR100264866B1 (en) 1998-07-13 2000-09-01 윤종용 Digital trank circuit for providing a plurality of trunk function
US6421443B1 (en) 1999-07-23 2002-07-16 Acoustic Technologies, Inc. Acoustic and electronic echo cancellation
US6166573A (en) * 1999-07-23 2000-12-26 Acoustic Technologies, Inc. High resolution delay line
US8057408B2 (en) * 2005-09-22 2011-11-15 The Regents Of The University Of Michigan Pulsed cavitational ultrasound therapy
US20070083120A1 (en) * 2005-09-22 2007-04-12 Cain Charles A Pulsed cavitational ultrasound therapy
US10219815B2 (en) 2005-09-22 2019-03-05 The Regents Of The University Of Michigan Histotripsy for thrombolysis
WO2011022411A2 (en) 2009-08-17 2011-02-24 Histosonics, Inc. Disposable acoustic coupling medium container
JP5863654B2 (en) 2009-08-26 2016-02-16 リージェンツ オブ ザ ユニバーシティー オブ ミシガン Micromanipulator control arm for therapeutic and image processing ultrasonic transducers
US9901753B2 (en) * 2009-08-26 2018-02-27 The Regents Of The University Of Michigan Ultrasound lithotripsy and histotripsy for using controlled bubble cloud cavitation in fractionating urinary stones
US8539813B2 (en) 2009-09-22 2013-09-24 The Regents Of The University Of Michigan Gel phantoms for testing cavitational ultrasound (histotripsy) transducers
US9144694B2 (en) 2011-08-10 2015-09-29 The Regents Of The University Of Michigan Lesion generation through bone using histotripsy therapy without aberration correction
US9049783B2 (en) 2012-04-13 2015-06-02 Histosonics, Inc. Systems and methods for obtaining large creepage isolation on printed circuit boards
EP2844343B1 (en) 2012-04-30 2018-11-21 The Regents Of The University Of Michigan Ultrasound transducer manufacturing using rapid-prototyping method
US20140100459A1 (en) 2012-10-05 2014-04-10 The Regents Of The University Of Michigan Bubble-induced color doppler feedback during histotripsy
US11432900B2 (en) 2013-07-03 2022-09-06 Histosonics, Inc. Articulating arm limiter for cavitational ultrasound therapy system
CN105530869B (en) 2013-07-03 2019-10-29 希斯托索尼克斯公司 The histotripsy excitation sequence optimized is formed to bubble cloud using impact scattering
WO2015027164A1 (en) 2013-08-22 2015-02-26 The Regents Of The University Of Michigan Histotripsy using very short ultrasound pulses
US11135454B2 (en) 2015-06-24 2021-10-05 The Regents Of The University Of Michigan Histotripsy therapy systems and methods for the treatment of brain tissue
WO2017106834A1 (en) * 2015-12-18 2017-06-22 Ursus Medical, Llc Ultrasound beamforming system and method with reconfigurable aperture
JP2018146520A (en) * 2017-03-08 2018-09-20 三菱日立パワーシステムズ株式会社 Ultrasonic flaw detection method, system, program, and storage medium
AU2018289337A1 (en) 2017-06-20 2019-12-19 Butterfly Network, Inc. Amplifier with built in time gain compensation for ultrasound applications
WO2018236799A1 (en) * 2017-06-20 2018-12-27 Butterfly Network, Inc. Single-ended trans-impedance amplifier (tia) for ultrasound device
US10857567B2 (en) 2017-06-20 2020-12-08 Butterfly Network, Inc. Analog to digital signal conversion in ultrasound device
US11324484B2 (en) 2017-06-20 2022-05-10 Bfly Operations, Inc. Multi-stage trans-impedance amplifier (TIA) for an ultrasound device
JP6993847B2 (en) * 2017-11-07 2022-01-14 富士フイルムヘルスケア株式会社 Ultrasound imager, ultrasonic probe, and transmitter
EP3886737A4 (en) 2018-11-28 2022-08-24 Histosonics, Inc. Histotripsy systems and methods
WO2021155026A1 (en) 2020-01-28 2021-08-05 The Regents Of The University Of Michigan Systems and methods for histotripsy immunosensitization

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4080838A (en) * 1975-11-12 1978-03-28 Hitachi Medical Corporation Method and apparatus for controlling ultrasonic waves
US4116229A (en) * 1976-08-30 1978-09-26 Hewlett-Packard Company Acoustic imaging apparatus
US4173007A (en) * 1977-07-01 1979-10-30 G. D. Searle & Co. Dynamically variable electronic delay lines for real time ultrasonic imaging systems
FR2399661A1 (en) * 1977-08-05 1979-03-02 Anvar Ultrasonic picture scanning equipment - uses grouped receive elements with phase shift and multiplexing to produce picture without shadow (NL 7.2.79)
JPS5444375A (en) * 1977-09-14 1979-04-07 Oki Electric Ind Co Ltd Ultrasonic wave reflection system
US4140022B1 (en) * 1977-12-20 1995-05-16 Hewlett Packard Co Acoustic imaging apparatus
US4127034A (en) * 1977-12-23 1978-11-28 General Electric Company Digital rectilinear ultrasonic imaging system
US4180790A (en) * 1977-12-27 1979-12-25 General Electric Company Dynamic array aperture and focus control for ultrasonic imaging systems
US4208916A (en) * 1978-09-13 1980-06-24 Picker Corporation Electronic ultrasonic sector scanning apparatus and method
JPS5584154A (en) * 1978-12-19 1980-06-25 Matsushita Electric Ind Co Ltd Ultrasoniccwave diagnosis device
JPS55106367A (en) * 1979-02-09 1980-08-15 Varian Associates Receiver delaying device for ultrasonic image forming apparatus
US4290310A (en) * 1979-07-09 1981-09-22 Varian Associates, Inc. Ultrasonic imaging system using digital control
DE2942049A1 (en) * 1979-10-17 1981-05-21 Siemens AG, 1000 Berlin und 8000 München DEVICE FOR ULTRASONIC SCANNING
JPH0138540Y2 (en) * 1980-06-30 1989-11-17
JPS5889007U (en) * 1981-12-11 1983-06-16 株式会社日立メデイコ Ultrasonic receiver
JPS58141142A (en) * 1982-02-17 1983-08-22 株式会社日立メディコ Ultrasonic wave receiving and deflecting circuit
JPS60196688A (en) * 1984-03-19 1985-10-05 Hitachi Medical Corp Scanning type ultrasonic wave apparatus

Also Published As

Publication number Publication date
US4829491A (en) 1989-05-09
DE3573341D1 (en) 1989-11-02
DE3425705A1 (en) 1986-01-16
EP0170072A1 (en) 1986-02-05
JPH0778492B2 (en) 1995-08-23
JPS6151560A (en) 1986-03-14
ATE46783T1 (en) 1989-10-15

Similar Documents

Publication Publication Date Title
EP0170072B1 (en) Phased-array apparatus
DE3918815C2 (en)
DE69012238T2 (en) Multi-lobe antenna system with active modules and with lobe formation through numerical calculation.
DE69023737T2 (en) Digital beamforming for independent multi-beam lobes.
DE2920828C2 (en) Ultrasound imaging system
DE19581713B4 (en) Baseband processor for processing signals from ultrasound receive beam-former - has complex response adjuster which operates on samples to effect phase and amplitude coherence between samples
DE69106049T2 (en) Ultrasound imaging device with adaptive phase aberration correction.
DE69126291T2 (en) Digital beamforming technology with temporal noise injection
DE3851892T2 (en) ULTRASONIC DIAGNOSTIC DEVICE.
DE69530069T2 (en) CIRCUIT AND METHOD FOR SUPPRESSING RADIO INTERFERENCE
DE69117709T2 (en) Ultrasound imaging system
EP0245740B1 (en) Method and device for the digital delay of ultrasonic signals upon reception
DE2920826A1 (en) ULTRASONIC IMAGING SYSTEM
EP0361264B1 (en) Digital input part for an ultrasonic apparatus
DE112008002254T5 (en) Digital radar or sonar device
DE2908747A1 (en) ULTRASONIC IMAGING DEVICE WITH SECTOR SCANNING
DE69223158T2 (en) RECEIVER BEAM FORM FOR AN ULTRASONIC DIAGNOSTIC DEVICE
DE3428046A1 (en) METHOD AND DEVICE FOR DELAYING AN ULTRASONIC SIGNAL
DE69622420T2 (en) METHOD AND DEVICE FOR REDUCING UNWANTED FEEDBACK
DE3742724A1 (en) DEVICE FOR PROCESSING ULTRASONIC IMAGES
EP0994358B1 (en) Procedure for determining the impulse response of a broadband linear system and measuring system for the same
DE2812575C2 (en) Phased antenna field
DE2446287A1 (en) MAGNETIC NUCLEAR RESONANCE SPECTROMETER
DE102005011768A1 (en) Method for controlling an ultrasound probe and ultrasound diagnostic device
DE69222702T2 (en) Ultrasound receiver

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT DE FR GB IT NL

17P Request for examination filed

Effective date: 19860226

17Q First examination report despatched

Effective date: 19880211

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT DE FR GB IT NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19890927

REF Corresponds to:

Ref document number: 46783

Country of ref document: AT

Date of ref document: 19891015

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3573341

Country of ref document: DE

Date of ref document: 19891102

ET Fr: translation filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950622

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19950628

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19950714

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950717

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960701

Ref country code: AT

Effective date: 19960701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19970201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970328

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19970201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20030916

Year of fee payment: 19

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050201