EP0170072B1 - Phased-Array-Gerät - Google Patents

Phased-Array-Gerät Download PDF

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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
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German (de)
English (en)
French (fr)
Other versions
EP0170072A1 (de
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/de
Publication of EP0170072A1 publication Critical patent/EP0170072A1/de
Application granted granted Critical
Publication of EP0170072B1 publication Critical patent/EP0170072B1/de
Expired legal-status Critical Current

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    • 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)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
EP85108128A 1984-07-12 1985-07-01 Phased-Array-Gerät Expired EP0170072B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85108128T ATE46783T1 (de) 1984-07-12 1985-07-01 Phased-array-geraet.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843425705 DE3425705A1 (de) 1984-07-12 1984-07-12 Phased-array-geraet
DE3425705 1984-07-12

Publications (2)

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

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP85108128A Expired EP0170072B1 (de) 1984-07-12 1985-07-01 Phased-Array-Gerät

Country Status (5)

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

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KR20200018812A (ko) 2017-06-20 2020-02-20 버터플라이 네트워크, 인크. 초음파 응용들을 위한 내장된 시간 이득 보상을 갖는 증폭기
KR20200018659A (ko) 2017-06-20 2020-02-19 버터플라이 네트워크, 인크. 초음파 디바이스 내에서의 아날로그-디지털 신호 변환
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Also Published As

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

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