DE1648341A1 - Ultrasound testing device, especially encephalograph - Google Patents

Description

* # ATI NTAN WXLTI

DR.-INQ. H. FINOKE β MUNICH β. 7 Q ^ FP 1QR7 DIPL.-ING. H. BOHR 'Μ »» »,. *«. * * '^' ^{l00 /} DIPL..INQ. S. STAEQER

Long distance call. * 2 << · «0

Folder 7241

Beech friction

ium patent application

of Automation Industries, Inc.

£ 1 Segündo, California, V.St.A.

concerning

"Ultrasonic testing device, especially encephalograph"

PRIOHITiTt October 3, 1966 - V. 8t. A.

The invention relates to an ultrasonic testing device for inspecting or measuring the internal ocular characteristics of a body or object and in particular to an ultrasound snoephalograph.

Certain Abno retail would act like a (throat shock, a tumor, subdurmle Häaatoae etc. call asyaaetrieohe Brüoke within

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the brainshell »These pressures work against the brain and cause one or more parts to be moved out of their normal position. Very often this brings about a shift a lateral displacement of the center line from its normal central position with it «Thus is. «As measuring the place the midline, and especially its lateral displacement, is a very useful diagnostic tool for presupposes the presence of various abnormalities-) accept. It has already been proposed to determine the position of the center line and / or its displacement using ultrasonic devices to eat.

The ultrasonic devices that can be used for this purpose can be divided into two classes, i.e. the transmission and pulse echo methods. In the forward transmission tester, a pair of transducers are placed on both sides of the test item arranged. Ultrasonic energy is then transmitted by a. nem transducer completely through the object to the transducer on the opposite side. The time required is so that the energy passes completely through the test item and / or the reception or the lack of one Receipt of this through transmission v, is used to determine some of the properties of the object. At the

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Irapulse echo tester is ultrasonic energy in the to be examined Object transmitted into it and all echoes that are reflected by the discontinuities arranged in it are received by the same transducer or a second transducer. The reception of the echo and / or the Receiving times are used to improve the properties of the item to be determined.

First, the location of the center line in the human head was determined using a pulse echo tester. A transducer was first placed on one side of the brain shell and the distance to the midline was measured by one ate the time it took to receive the echo from the center line. Subsequently, the Transducer placed on the opposite side of the brain-shell and the distance from that side of the brain-shell measured to the center line. By comparing these two measurements, it was possible to determine whether a Shift of the center line had taken place.

Obviously, such a technique is slow and arduous. Because operations are carried out by hand on a large scale must, is such a procedure of high discretionary discretion exposed. In addition, the staff

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tellinie a complex tissue structure that produces a correspondingly complicated echo "In addition, ^a number of other Grewebestrukturen or discontinuities ü-n close to c ^ r centerline present which are capable of an echo e ^ eugenc The results of these measurements were often misleading UOD / or have been misinterpreted.

To overcome these Sehwierigkiiten, an improved ultrasonic Ence ^ was halo graph developed to facilitate the measurement of the shift of the center line and ₀ A Encephalograph di "-3" r type is disclosed to increase the accuracy and reliability of the measurements and described in the related US patent application 440 231 of March 16, 1965 (corresponding to German patent application A 51872 IXb / ^ 2k ) or the corresponding continuation-in-part application No. 518 575 (corresponding to German patent application A 51t72 IXb / ή2k) With this encephalograph, a pair of voi. Transducers placed simultaneously on opposite sides of the patient's head, and a cathode ray osuilloscope produces a continuous, visual representation of the various operations of the transducers? whereby the user can very quickly determine the accuracy of the measurements and their significance

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The encephalograph operates automatically according to a sequence of different modes of operation, an echo being received from the right side of the median line 3, an echo from the left side and / or a transit (transmission) pulse being received. The oscilloscope simultaneously produces a first display that shows the distance from the right side of the brain shell to the center line and back, and a second record or display that shows the distance from the left side of the brain shell to the center line and back, and a third record or Reproduction that corresponds to the distance between the two opposite sides of the brain shell < If the encephalograph is working correctly and the center line is centered, then all three reproductions are aligned or aligned. If the reproductions do not align, the center line is shifted and / or the encephalograph does not work properly «

By making a quick observation of the reproductions and especially of their relative positions, However, it becomes possible for the user to determine completely unambiguously whether the center line is possibly in the really centric position is located or is shifted from this, namely by how much "

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Such an encephalograph has been found to be useful for diagnostic purposes and research purposes as it provides highly reliable and accurate information. JSs has however found that a certain skill and experience are required to operate the encephalograph in a truly effective manner. It has gone beyond that found that some dexterity and training are necessary to get the optimal amount of information of the different. To receive renditions "

The measure according to the invention is now intended to be an ultrasound encephalograph compared to the known are considerably improved. The aim here is that the encephalograph is not only cheaper and easier to manufacture, but is also suitable for use by relatively inexperienced users Suitable for people. This is achieved according to the invention with an ultrasonic testing device for measuring an acoustic Target within a workpiece, especially in the case of an encephalograph, by means of ultrasonic transducers that are suitable are to be acoustically coupled to the workpiece} second Devices that are effective for feeding the transducer according to a first type, in the case of the ultrasonic energy in the workpiece, in a first way towards the target

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is transmitted, wherein Dierse r.weiten devices _r generate a first electrical signal having a puncture of the position of the workpiece is rarget inieraalb, wherein the break in devices ate. Excite or feed transducers according to Pirier of the second type, whereby ultrasonic energy is transmitted into the workpiece according to a specific type of target, whereby the other devices generate a second electrical signal which punctures the position of the 2 targets are within the workpiece, and that brewing devices: are coupled to transducers and second devices and are responsive to the first and second signals to generate a position signal that is a puncture of the target's location _e

The Snceplialograph according to the invention is able to provide a reading of the displacement in a perm which can be read and understood more quickly , especially by relatively inexperienced users »

For example, when the encephalograph is designed, a pair of transducers is provided: on both sides of the brain shell, the encephalograph automatically actuates the transducer :? one after the other in different ways, whereby

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a pulse echo right, a pulse shot left and a through transmission are made * The resulting signals are then processed and automatically compared * in order to generate one or more signals, which are the punctures of the displacement of the center line now under the influence of these displacement signals, whereby the direction and size of the possibly existing displacement appear directly on the scale of a conventional measuring device Presence or absence of a displacement of the center line and, if there is one, its size

The invention will now be based on a few exemplary embodiments with reference to the accompanying drawings ^ are explained in which

1 shows an illustration of an ultrasonic testing device the so-called echo-encephalograph design is »especially for use in measuring the lateral displacement the center line of a human brain j

Figo 2 is a circuit diagram of the ultrasonic testing device according to IiQ, 1 j

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Pig. Figure 3 shows a number of waveforms appearing at various points in the block diagram of Pig, Figure 2;

4 shows an ultrasonic testing device according to a further embodiment of the invention?

Fig. 5 is a block diagram of its cable of the circuit used in the embodiment of Fig. 4; and

FIG. 6 shows a number of waveforms which appear at various points in the block diagram of FIG.

According to the drawings, in particular 1, 2 and 3, the invention is Particularly suitable for an ultrasonic testing device 10, through which the internal structure of a test object or workpiece is being investigated. The workpiece can be a wide variety of things; in the present case however, the description will be given using an encephalograph for examining the human head 12

From Fig. 2 it can be seen that the human head 12 has an outer protective cranium 14 which is is a relatively rigid bone structure that encloses and protects a cranial cavity. The brain 18 is internal

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half of this Hohlr & vjnes) arranged and wirs. protected by the brain shell 14. The brain 18 is divided into right and left lobes 20 and 22 by a so-called center line 24. The center line consists of a relatively complex fabric structure which exhibits a greater acoustic discontinuity against the passage of ultrasonic energy & a £ »

The center line is usually in a plane, usually vertical, with the opposite sides of the Skull 14 and the two flaps 20 and 22 are arranged essentially symmetrically around this. Here is; so the distance from the right side of the head 12 to the centerline 24 and back is equal to the distance from the left side of the Center line and back. Also, both distances are equal to the total distance from one side to the other,

Certain types of abnormalities such as concussion, tumors, subdural hematomas, etc., produce asymmetrical pressures within the cranial cavity 16 _e These pressures can take effect and shift the brain 18 so that the center line 24 laterally from a truly centric position to one side of the skull 14 is moved.

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"• 11" »

For example, the center line 24 is a complicated tissue structure that represents an acoustic discontinuity. It follows that ultrasound energy is reflected from it. The ultrasound encephalograph 10 according to the invention is particularly suitable _for exploiting this advantage and the position of the center line 24 and / or the size de :? Lateral displacement of the midline 24 to a really centric or s ^ rmmutriean position

The encephalograph 10 consists of a Psia :? of ultrasound soyons 26 and 2B ₁ which are acoustically coupled to opposite sides of the test object or workpiece,]> for example the head of the patient 12 have a piezoelectric crystal therein to transmit or receive ultrasonic energy. If an electrical signal is applied to the crystal, the crystal vibrates mechanically and emits a steal tone ultrasclial orgy. If, on the other hand, the crystal msphanisoli is excited by ultrasonic energy, it emits a corresponding electrical signal *

Jade of the probes 26 and 28 is with the tester 10 mi of a suitable? coaxial cable 30 and 32 connected. If-

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wofc ', 1 the two. I-lube.l 3ö uiiu y ?, mechanisah. If they are advantageously electrically insulated from one another, shafts can best be seen from Pig 2? The cables 30 and 32 for the right and left bonds 26 and 2B are electrically connected to right and left channels 34 and 2, respectively 36 doubled within the 33neephalographön 10 ", each channel 34 and 36 has a pulse generator-Iirapfanger 38" 44? A limiter 40-46 and a gate 4.2-48

The pulse generator Ktipfänger 38-44 are advantageous in essence identical to each other rnvt of the usual design. Each includes a controller input 50-52, an exercise: etragimgß / receiver ~ IQ.eißi; ie 54-56 and a signal output 58-60 c The controller terminals 50 and 52 are inside to oinen inside the pulse generator provided for the pulse generator The Reglerklemmeii 50 and 52 are coupled to the outside with a Clock 62 coupled via a selection gate 64. The clock 62 is used to create a series of trigger or clock pulses to generate- the among other c.en operation of the whole Systems synchronize and also its pulse train sequence rules ο in the present case, eg lends a hand these impulses around a series of Reohtecik waves similar to those in Figure 3A. Xramer then »when a trigger or clock

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pulse is given to a control terminal 50 or 52 is generated the associated pulse generator generates an electrical pulse of the ultrasonic frequency at the transmitter-receiver terminal 54 or 56 «These electrical impulses are given to the respective probe 26 or 28, whereby the probe a corresponding Emitted pulse of ultrasonic energy

The selection gate 64, which may be of conventional design, includes a signal input 66, a pair of controller inputs 67-68 and a pair of signal outputs 71-73. The signal input 66 is coupled to the clock generator 62 and, if there is a signal (for example positive potential) at the first controller input 67 is present, the clock pulses are transmitted to the right pulse generator receiver via the first output 38 coupled. Conversely, if a signal, for example with positive potential, is present at the second input 68, the clock pulses through the second output with the left pulse generator receiver 44 coupled *

The mode of operation of the selection gate 64, ie its state, is regulated by a ring counter 70. The ring counter has several outputs and a single controller input 78 coupled to the clock 62 via a counter 80. The counter ÜO can be a conventional counter, for example

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wisely act a series of plip-flops which impulses the saktgeber and that always generates an output pulse ι when a certain number of clock pulses occurs. These pulses define a frame rate and are usually of the order of magnitude one fifth of the clock sequence, i.e. five clock pulses occur during each frame.

According to this embodiment, the ring counter 70 comprises three separate outputs 72, 74 and 76. Two of these outputs are connected to ground potential, while the third output has a positive potential. This results in a series of rectangular waves similar to lines B, C, and D in Pig. 3 ο As soon as an image is completed, the counter 80 provides a pulse to the ring counter 70. This becomes the ring counter 70 causes the shift to the next following state. During the first or through picture is the

. Output 76 at positive potential and outputs 72 and 74 have measurement potential · During the second or right image the output 72 is positive, the outputs 74 and 76 have hate potential. During the third or left image, the second output 74 is at positive potential, the first and third outputs 72 and 76 have hate potential.

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The outputs 58 and 60 from the pulse generator-receivers are at limiters 40 and 46 in their respective channels 34 and 36 coupled so that the radio frequency signal (RP) is supplied thereto. The signal includes site variety of Echo pulses and has a pulse repetition frequency accordingly the repetition frequency of the! Aktgeberimpulee. Every period comprises a pulse of great amplitude corresponding to the sound pulse of the greatest energy, i.e. corresponding to that transmitted Ultrasonic pulse. This is followed by one or more impulses low amplitude, which is the return echo of the transmitted Represent ultrasonic energy that was received by the probes 26 and 28 and / or the energy that passed entirely through the head was crossed from one son'le to the other.

The time delay ewinofeen iS2i pulses greatest? "Energy and the next pulse corresponds to the time delay for the received signal and therefore the area or distance .of the target · In the case of through transmission, the Area equal to the distance between one side of the centerline 24 and back to the same side. So if a reflective Surface, i.e. the center line 24, is arranged exactly in the middle, then the land is from one side to the Mr.tte and back geaex ßleish dom distance from one side

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on the other * It follows that under ideal conditions the The time between the pulses of greatest energy and the next pulse will be identical < >

The limiters 40 and 46 come into operation to match the amplitudes of the large signals with the main energy (main bang pulsee) and to prevent overloading of the system »The amplitudes of the smaller echo pulses are however not significantly changed; "

Each of the gates 42 and 48 can be of any of many known types having a signal input 86 and 88, a controller input 90 and 92, and a signal output 94 and 96. Are any signals on a controller input 90 or 92 ₉ d.he at ground potential ₈ so the gate remain 42 or 48 are closed ,, whereby no signals pass herein may _β However, when a regulator signal, for example with the positive square waves of the lines B, G or J ) are applied to don Eeglereingang 90 or 92, the gate 42 opens or 48, and remains for the Sauer the controller signals ox \ _f fen whereby the high-frequency signals from the limiters can go through respective here, "

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1? ~

The signal outputs © 94 and 96 from the two gates 42 and 48 are coupled together and combine the limited and high frequency signals passed through the gates in a single composite high frequency signal. The resulting composite © high-frequency signal is then transmitted through a receiver 98 and video amplifier 100 are fed, which serve to.} record the high-frequency signal and deliver an amplified video signal »

The video signal is similar to line E in Figure 3 and includes during each amplitude a pulse of the greatest energy with a large amplitude and a target pulse of low amplitude The time delays between the pulses of greatest energy and the target pulses (that is, the horizontal distance between the pulses in Figure 3E) are a function of the distance to the targetο

The first control signal 67 of the Vahlgatters 64 is directly with the central output 74 is coupled to the ring counter 70, while the second control signal 68 is coupled to the first and third outputs 72 and 76 is coupled by means of an OR gate 82. The right gate is coupled directly to the output 72, while the left gate 48 to the second and third outputs 74 and 76 coupled by a second OR gate 84 is.

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During the first oc, he major eiigangsbi ides is the left pulser 44 except] unction _r? Reohte the gate 42 is closed "However, when the right pulse-works 38, then d £, s left gate 48 open. Thus becomes a. Pulse given to the right transducer 26, v / o by ultrasonic energy through the. Head is transmitted to the right transducer 28 _e The resulting high-frequency pulse v / is then coupled through the gate 48 with the receiver. During the first picture the time between the sound impulses of greatest energy and the target impulses corresponds to the width of the head,

The right pulse generator is 38 during the second image still without function "The left gate 48 is now closed, the right gate 42 remains open." Thus represents the respective length of time between the pulses now the distance from the right side to the center line 24 and back In the third picture, the left pulse generator 44 is active while the right gate 42 closes and the left gate 48 opens. Under these conditions make the temporal Delays between pulses represent the distance from the left to the centerline 24 and back.

The output of the video amplifier 100 is connected to the signal input 102 of a pulse or ramp generator 104 given and

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supplies this with the video signal. This generator 104 can be of conventional design and has a regulator or control input 106 and a signal output 108. V / ird a control signal • For example, a positive square wave, given to the control input 106, the generator 104 is free and output 108 biased against hate potential. So long the square wave is present at the control input, the output with ground potential is independent of the potential at the signal input clamped.

However, as soon as the square wave ends, the linear velocity output 108 becomes more negative to positive Inpuls is given to the signal input 102. If such a Ijipuls occurs, output 108 is returned to ground potential. It will be shown that the signal at the output ι08 consists of a series of negative running ramp waves or sawtooth waves is similar to the "m" in Fig. 3G. The amplitudes of the waves are a puncture of the duration of the Jächoimpuloe =

The control input 106 ft '.r of the run-up or barrier generator 104 is applied to the clock generator 62 via a monostable multivibrator or a univibrator 110. Normally, the multivibrator 1IC remains in a stable state, with the output being held at ground potential. If a clock occurs

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pulse on, the multivibrator 110 switches to the stable state and remains in this state for a certain period of time _p before it returns to the stable state.

The duration of the astable state is determined by the size of the Voltage at a regulator input 112 regulated. The multivibrator generates a series of square pulses (Figo3P) » whose beginnings are synchronized with the clock pulses »The end or the duration of the square waves is a puncture of the potential at control input 112 «

present control input 112 is with a single pole Double throw switch 114 connected. If the switch 114 is in the position shown, then it connects the input 112 to a fixed voltage 115 <> This ensures that the square waves have a have a predetermined fixed duration. Usually the square waves are long enough to hold the sound pulse of greatest energy to include. This ensures that the output of the bar generator 104 is at ground potential is still clamped for a certain time after the sound pulse of the greatest energy ο

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When a square wave ends, the generator 104 begins negative going edge signal according to FIG. 3G and will continue to run down "until the target pulse is given to input 102. This pulse corresponds to the first echo generated at the center line 24 or the reception or the transit transmission.

The output from the edge generator 104 thus consists of a series of pulses synchronized with the clock generator Sawtooth pulses. The individual amplitudes of each sawtooth wave are proportional to the time delay of the pulses compared to the target and are therefore proportional to the Distance to the target.

The signal output 108 from the edge generator is with a Edge control gate 116 coupled. This gate 116 can be of conventional design and can be viewed from a functional standpoint as three separate but interrelated gates. The gate 116 comprises three separate control inputs 118, 120 and 122 as well as three separate signal outputs 124, 126 and 128 there are also no signals at outputs 124, 126 and 128

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on o is however a positive / running o signal on the first or right input 118 is present, the input signal goes to the right output 126 via »A signal on the left input 120 generates a signal on output 128, and a signal on the third or port input 122 couples the signal from the input to the output 124 «

The control inputs 118, 120 and 122 are connected to the outputs 72, 74 and 76 of ring counter 70 are coupled so that the square wave signals of Pig * 3 (B, G and D) are received will. As a consequence, the control gate 116 operates synchronously with the selection gate 64, the right gate 42 and the left gate 48 and is used to "sort" the board signals β

So it can be seen that a row appears during the first image when the tester is operating on continuity transmission of edge pulses, through gate 116 to output 124 The amplitudes of these edges represent the width of the head 12. During the next image, when the test device 10 On through-laser transmission work.at, the edge signals pass through gate 116 to output 126 · The amplitudes these flanks reflect the width a of the head 12. Select

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rend finally daa tester on the left with Inpulsecho works «are the edge signals with the third output 123 coupled ,, the amplitudes of these signals represent the distance from the left side to the center line 24 and back »

The three outputs 124 * 126 and 128 from the edge control gate 116 are separately coupled to the three pointed voltmeters 130, 132 and 134. Each of the voltmeters 130 ₈ 132 and 134 responds to the maximum amplitude of the board signal at its signal input 136, 138 and 140 and supplies a DC signal equal amplitude Every time a 3? the voltmeter will be ready to take action to store the DC signal for multiple images without significant degradation in the DC level

Thus, the forward voltmeter 130 creates a direct current signal, since there is a puncture the width of the head, the right voltmeter 132 provides a DC signal indicating a puncture

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of the double abroad between axis 24 and right Side is. The left voltmeter 134 supplies a line current signal, which is a function of the double distance between the center line 24 and the left side "

The output from forward voltmeter 150 can be connected to either suitable display device "for example" in a conventional measuring device 146 be coupled. The signal from the forward voltmeter 150 is a direct current signal with an amplitude corresponding to chend de :? Width of the head 12. The measuring device 146 canoe accordingly be calibrated in suitable units, for example millimeters, inches, etc., which allows the user to determine the width of the headB can determine by observing the display on the meter 146. In addition, the output of the Passage voltmeter 130 with its output on the respective first side 152 and 154 of one. Pair of signal comparators 148 and 150 coupled.

| The opposite side 156 of the first comparator 148 is coupled to the right voltmeter 132, the second side 158 of the comparator 150 is coupled to the left voltmeter 134 coupled. These two comparators 148 and 150 are of conventional design and are used to detect the differences between

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see the signals on the opposite sides 152-156 and 154-158. The signal at output 160 of the first comparator 148 represents the difference between the pass signal and the right echo signal, while the signal from the output 162 of the second comparator 150 is the difference between the pass signal and the left Represents echo signal

The outputs 160 and 162 from the two comparator forums 148 and 150 are coupled directly to a right measuring device 164 and a left measuring device 166. These two heaters 164 and 166 are usually centered on zero and indicate both positive and negative signals. Let the center line 24 be centered correctly, the two echo signals have the same time delay as * the through signal} thus the right and left measuring devices 164 and 166 are perfectly centered. If the center line 24 is shifted, the signals no longer remain identical to one another. The measuring devices 164 and 166 thus indicate • in · displacement in one direction or the other.

The output from the forward voltmeter 130 can also be coupled to a holder 168 which leads to a third signal co-capacitor . This switch 168 can be operated with the

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going switch 114 (mechanically for synchronization) are coupled. When this switch 168 closes, it will Pass signal given to side 170 of the signal comparator. The opposite side 1? 4 of the! Comparator A standard voltage 176 is applied.

The output of the comparator 172 is applied to the input 11Γ: The differential signal given by the monostable multivibrator 110 by means of an amplifier 178 and the closed switch 114 regulates the astable period of the multivibrator 110.

The standard voltage is usually set to a certain level set depending on the expected width of the examined head Ί2 as well as with regard to the maximum expected Shifting the center line. If a transmission transmission signal is received at the correct point, the transmission transmission signal is approximately equal to the standard signal on the Second page 174 of the comparator 172. The difference signal then podifies the astable period of the multivibrator 110 and makes the system 'preamble' to the transmission transmission signal, producing a constant difference signal from the Comparator 172 is generated.

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Under these circumstances, if a transmission transmission signal is received at the correct time interval, the transmission meter 146 will respond appropriately to a particular reading (lock-on.) _C

■ S 'in the event that a transmission transmission signal is not within of the prescribed time limits is received, voltmeter 130 does not respond to any particular one Signal on, the output signal becomes abnormally small or abnormal great. This abnormal signal is now beyond the resolution capabilities of the comparator 172 and the monostable Multivibrators 1'sQ. Thus, the permeability meter 146 is shown outside the scale range. Even the left and right Gauges 164 and 166 are likely to be "outside." of the scale range "display,

It turns out when a Durchlaßtransinissionssignal is not received correctly, the user of this fact is immediately aware ,, because all of the three instruments 146 '164 and 166 show outside the scale range · Once was made to be the right correction ₉ to the Durchlaßübertragungssignal to received, the passage meter 146 indicated the standard or KuIl condition

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and the right and left gauges 164 and 166 show instantly the differences, i.e. the size of any shift in the center line.

To this one. Encephalograph 10 to m measuring the position of the midline 24 2U use »the two probes 26 and 28 The counter 80, acoustically coupled to the opposite sides of the head 12, counts the clock pulses and ^ every time a picture is completed, he delivers

an image signal to the counting counter 70. Every time an image signal occurs, the ring counter shifts to the next position »So the signals to the three outputs all the three square waves like them by lines B, C and D in Pig. 3 are shown «,

During the first or transmission frame, the left pulser 44 is inactive and the gate 42 ver = remains closed. The selection gate 64 is, however, set so that it always uses the right pulser receiver 38 then triggers when a clock pulse occurs. The left gate 48 is open, causing the through-hole transmit pulses are coupled in the left channel 36 by the receiver 98 and to the plan generator 104 "

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The square wave (Mg.33?) Of the mono-stable multivibrator 110 clamps the output of the Flarikengenerator 104 during the sound pulse of the greatest .Energie against ground. At the end of this interval, the edge generator 104 includes an edge pulse (Fig.3G) an amplitude begins to generate linearly _f rises up to the target or Airchlaßimpuls occurs., Me amplitude of these pulses during the image therefore corresponds to the width of the head 12 ', while of this image, the ring counter 70 sets the edge control grid 116 so that the video signal is fed into the pass-through peak funnel to & s knife 130 o The voltmeter VjQ thereby generates a direct current signal with an amplitude corresponding to the width of the head 12. Yfeiden the switches 114 and 168, as shown is set, the flow meter 146 adjusts the width of the head 12. However, switches 114 and 168 are usually set to the other position. As a consequence, the pass signal is also coupled to the comparator 172 for comparison with your standard signal. The resulting Differenzsi jnal then adjusts the multi-vibrator 110, so that the spark generator 104 is unlocked shortly before the time at which it is expected that the Durchlaßübertragungs-iiargetsignal ,, aeftritt "That enteperrte interval is usually .just so long" to the

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to record early arriving echo signals from a shifted center line 24. Thus, any unwanted signals occurring before this point in time will not be misinterpreted as a pass signal _{or the like}

When a pass signal is received, the voltmeter 130 leaves a signal within the resolution capabilities from comparator 172 and multivibrator 110 sr testify. Through this the closed-loop feedback is then just set again, so that the generator 104 by a fixed Interval before the pass signal becomes free. Through this a constant output signal is generated and a reading with a particular value is produced in the measuring device 146. The user can now very quickly determine that a transmission transmission signal has been received and that the System 10 responds to this. If such a transmission signal does not occur or the system 10 does not respond to it on, the signal is excessively small or large and the meter 146 outputs one across the range of the dial to the right or reading going out to the left.

At the end of the first or transmission images, the counter 80 generates an image signal and shifts the ring counter 70 into the next state. Under these conditions is the

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Unite pulse generator 44 inactive, the left gate 48 is closed However, the first pulser-receiver 38 will excited, the right gate 42 opened during this picture thus includes the signal coupled to receiver 98 a series of sound impulses of greatest energy, followed by right

The monostable multivibrator 110 clamps the I * lanke generator 104 to ground during the same interval, as it was set in the previous Durchlaßbild ", the generator 104 is released shortly before the date * su where the right echo signal from the center line 24 arrives _o the generator 104 generates a Sägeaahnwelle (FigajJG) is received until the right echo pulse _c As this occurs within a very short time interval _P is small, the probability "that a false signal ended the pulse

During this picture, the ring counter 70 sets the edge control gate 116 by coupling the flank cone pulses with the Right peak voltage ground 130 a “This voltmeter 130 then generates a direct current signal with a Amplitude proportional to the distance from the right side of the head 12 to the center line 24 and back. The right Si

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gnal is put into the comparator 148 and with the forward transmission signal The difference signal compared with the resulting difference signal is then sent to the measuring device 164.

At the end of the second image, the Abaäixler 80 generates a. Another image signal shifts the ring counter 70 again to the next following state. Under these conditions, the right gate 42 remains closed, the right pulse generator 38 is inactive is open ", Pae aai the. Receiver 98 signal now consists of sound impulses larger * ü (." r Energy Bowie linlcen Echoiiapuls ^ vio The i'l; inJcengsnerator 104 erssugi; now a series of plank impulses, which through the]? la .i3: siiBteuergatter an dai3 liiücö Yoltmeje:? "134 will be given; ·!. ·. Here again take Qii 6io Iiapulse -toü the Planliieniiapulsgono ^ ator 104 their Äiiogar> ^ _? course before the left Echosig: usl arrives to the lKi | : l.:. ahk3it hp ^ submitting that a f -. tlsches signal detects vr.rä «The signal from Spanmirigsnesser 1'54 is thus a mivJröion of the distance from tier linit ^ iL Soitö of the head 12 .. Moses' left signal is given into the Eo.sparator 150 and with the passage ~ laßsignal Yerglialicii, The resulting Bi is then gekoppe3.tr with the Usß ^ orät '66 .

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The result is that when the switches 114 and 168 are set as shown, the user can quickly read the width of the head 12 on the scale of the measuring device 146. If the switches 114 and 168 are then reset, the system 10 speaks on the pass signal, the meter 146 shows a fixed amount (the. system will look on). At the same time, the user can specify the position of feet of the center line 24 by 164 and 166 l · he abachtet the meters. If the center line is perfectly centered _t fco; ind right and left DC signals are both equal to the zero signal and the left and right meters indicate zero, ie they are perfectly centered. Thus, by observing both points in their central bearings, one immediately knows that the central line is centered.

If the center line 24 is shifted to one side, the echo signal from this side is smaller than the transmission signal; and the echo signal from the other side becomes larger. In the present Pail the center line 24 is shifted to the right and the amplitudes of the plank impulses (Pig 3G) wan The second picture are smaller than those during the first picture.

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These differences produce positive and negative differential signals at the outputs of the comparators 148 and 150. The differences are displayed on the two measuring devices 164 and 166. So the user can choose direction and Observe the amount of displacement by monitoring the readings on the two meters 164 and 166.

Then when the right and left signals during the second and third images correspond to the position of the center line 24, but the two difference signals are equal to one another of opposite polarity, but if the Jächo V are generated by the same target, the Am-

n of the difference signals are not equal to each other. This state can occur if the echo originates from the center line 24 on one side, while the echo from the other side originates from a false target, for example one from a brain ventricle. With switches 114 and 168 set to close the feedback loop, system 10 will respond to the pass signal and the likelihood of this occurring is greatly reduced. The occurrence of a paleo function can be quickly determined by observing whether the two readings are equal in magnitude to one another.

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If they are not the same, the probes 26 and 28 can be adjusted until they are on top of each other and on the center line 24 are properly focused so that the meters display symmetrically.

An alternative embodiment as shown in the Pig. 4 _f 5 and 6 can be used. The encephalograph 200 UB comprises a single indicator, for example a common measuring device 202 and not a plurality of measuring devices as in the first embodiment. The first measuring device 202 is used to indicate whether there is a shift in the center line and what direction and dimensions this shift, if any, has. If a useful attempt is not given, this fact is indicated by a flashing light 20 ?, a bell and / or the measuring device 202 itself.

Fig. 5 is a block diagram and relates primarily the parts of embodiment 200 that differ from the previous Execution form unteracheiden. Most of the parts of the two devices are identical and therefore not listed twice. These two embodiments are common Elements have the same reference numbers, but with the addition of a dash (')

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The ^ 200 Wellenfcrmen occurring at dsn where points spank of Encephalograph recorded in Figc 6 _o Normally, this embodiment operates in the manner described with reference to the first embodiment, Arto For the sake of simplicity but is only eino single operation at every image displayed during the first image transmits and receives the left transducer 28 transmits a NaOH Impulsechoverfahreüc Währerad receives the second image and the right transducer 26 for a Impulseehoverfahren ₀ During the third image sends BAW * on the left-side transducer 28 and. the right converter 26 receives after the passage over tr aguiig seeerfahren »

The video amplifier 100 ¹ is essentially identical to the first video amplifier 100 = it is connected to the output of the. Receiver 98 _r so that it receives and amplifies the composite video signal. The video amplifier 100 ¹ has a double. Output connected to a pair of channels 206 and 204 for separate delivery of the video signal to both «,

The first channel 204 is used for each position of the center line measure and display each shift * The second channel

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däfiu serves to verifizierenj that a valid measurement is performed, and thereby to recognize your user to specify whether optionally Diö from the first channel 204 readings produced reliably _o

The singing input on each channel includes locking gates 208 and 210. ₃ accessories are of a known type and are used _{to close 9} over certain time intervals, always when a timer signal is applied to the control output. The two control inputs 212 and 214 are with connected to the departure of the clock 62, whereby the Gattei? 208 and working synchronously with the sounding impulse of the greatest energy, that is the transmission of the initial impulse *

The first gate 208 has a short closing period, while the second gate 210 has a long closing period. The first gate 208 closes ¹ , shortly before or at the same time as the start of the ignition pulse of greatest energy and opens again shortly after this pulse, ie H. before the earliest from a center line derived echo Dios leads dasu that the output of this gate 208 of a series of pulses corresponding to those represented by curve C in Fig. 6, ₀

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During this first frame, the left transducer 28 transmits and receives, causing the first pulse to echo from the left side of the midline and the second pulse an echo from the opposite or right side of the skull is equivalent to. Since this echo is received by the left transducer 28 on the left side of the head, this will be referred to as left television echo «During the next The signal from a first pulse is shown accordingly an echo from the right side of the midline and an impulse from the other far side of the skull. This is hereinafter referred to as the right far side echo. There is only a single pulse during the third frame. This impulse is generated by the transmission transmission and represents the width of the skull.

The output of the blocking gate 208 is given to one of the control inputs 216 of a flank gate 214. The other rule input 218 is applied to the clock generator, whereby the operation of this gate is synchronized with the transmissions or transmissions. The input signal 220 of this gate 214 is coupled to an edge generator 222. The edge or ramp generator 222 is also connected to the clock 62 and generates an edge or saw

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cog shaft that starts every time a clock pulse occurs and increases a fixed linear velocity or sequence.

Icuner darn when a clock pulse occurs at input 218, opens the edge gate 214 and remains open until the first Ixnpula at .Eingang 216 from the blocking gate 208 received is.

As a result, the signal at the output of this gate 214 consists of a series of sawtooth waves, the Amplitude of each wave of the period between the ultrasonic pulse greatest energy and the first after that, occurring Signal corresponds. During the first picture the amplitude of the J ^ lank signal represents twice the distance from the left to the center line · During the second pulse the wave amplitude is double Distance from the right to the center line. During the third pulse, transmission occurs and the Amplitude corresponds to the width of the head, for an average head with a center line, all of the three signals are the same size, for example 10 V. If the head is wider or narrower, the signals are ao

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correspondingly larger or smaller than this size «Moves When the center line is reached, these signals reach a greater height, for example 12 V “while the other Signa], by the same amount to a lower level, for example 8 V, falls.

The output of the plank gate 214 is with the flank control gate 224 coupled »This gate 224 is essentially identical to the first stouor gate 116 and possesses the three control inputs 226, 228 and 230, which are on

a ring counter 70 'are connected. The barrier control gate 224 also includes three outputs 232, 234 and 236, _x which are used to convert the barrier signals occurring in series into signals occurring in parallel. The three signal outputs 2323, 234 and 236 are connected to left, right and forward peak voltage meters 238, 240 and 242, respectively. These are essentially the same as those shown in the first embodiment and are used to generate light current signals which correspond in amplitude to the peak amplitudes of the planks. As can be seen, the output from voltmeters 238, 240, and 242 are each double the distance from the left side of the head to the center line, double the distance

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from the right side to the center line and the width of the head β

The outputs of the linlcen and right voltmeter are connected to the opposite sides of the indicator meter 202 connected. The meter 202 has the zero point in the center and is of the filei voltage variety. JSs »eighs both the Amplitude like the polarity by deflection from the it'.tte left or right.

If Eohos are now received from both sides of the center line and “if the center line is correctly centered, then they are For example, the left and right signals are equal to each other equal to 10 V. The meter 202 shows this difference, i. Zero, on, The meter 202 thus indicates to the user that the centerline is centered. On the other hand, differs then, when the center line is shifted, the left signal from the right signal. For example, a signal can be 8 V, the other 12 will be 7 tall. The polarity of this difference represents the direction of the shift and the amplitude is equal to the magnitude of this shift Display the amount and direction of the shift so that the user can quickly observe this measurement.

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The arrangement described above is inherently capable of giving an accurate indication of the displacement of the center line. However, it has been found that under certain circumstances one or both of the transducers 25-28 may not be properly connected to the patient's head. Under certain circumstances, the transducers may also not be correctly aligned with one another, "which means that a transmission does not occur or the devices from one or two sides of the center line are not received correctly". Ee has also pointed out "that in some cases an abnormality, for example" in tumor, blocks the passage of the ultrasonic energy. Any one or more of these or other factors can now cause the encephalograph 202 to generate displays "capable of misleading the user "For this reason, the second channel 206 is used to determine" whether a valid attempt is being made "so that the user knows that he can rely on the displays.

The blocking gate, which forms the input to the second channel 206, can be constructed essentially in the same way as the gate 208, except that, as previously stated, this is a longer one Has closing period. Sas gate 210 is with the clock

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62 coupled, so-dal? ee shortly before ader simultaneously with closes the sound impulse of greatest energy. The gate 210 remains closed until all echoes reflected at the center line have passed »Gate 210 opens before receiving the echoes coming from the far side of the As a result, the output signal includes a delayed pulse corresponding to the Distance to the distant side of the skull unc. r; back. This, of course, is essentially doubled the width of the bowl. The output i3t similar the line G to Pig. 6 and comprises during the first -BiI-4 * β a single one representing the left far side echo Pulse received by the left transducer 28. In the second image, the impulse represents the right core side echo, as received by the right transducer 26. Through transmission occurs during the third frame and solid t no TV echoes are received. While there are no impulses in this image.

The output from lock gate 210 is via one of the control inputs 24-6 connected to a plank gate 248 essentially the same as that of the preceding gate 214. The second Control input £ 50 is coupled to the clock generator 62, see above

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that a Synclironioiersignal can digest received. The signal input 252 is connected to an edge generator 222 and receive an edge signal identical to the im First gate 214 delivered «The output from the plank gate 248 thus represents a series of sawtooth flanks Peak amplitudes during the first and second images are shown which correspond to the left and right target sides no iSehoimpulae occur during transmission, If the gate 248 remains open, the plank generator is 222 completely down or runs out and the i »ä ~ Toothed shafts at the liaximal limit d ^ £ generator 222 take their bottom Yfert (bottoms).

An edge control gate 254 is coupled to edge gate 248 sin iapfang of the saw tooth shafts connected »This gate 248 eats similar to control gate 224 "except that just a pair of rule inputs 256 and 2f5f. and a la & r of exits 260 and 262 are present and both handle entrances 256 and 258 are coupled with the low-speed counter 70 ', whereby the gate opens during the first and second images, so that the right and left junction edges on the two signal outputs 260 and 262 are "sorted".

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The two outputs? 60 and 262 aiii *! with a right one Pernaeitenvoltmtftsr 264 and a left FernstItenvolt « meter 266 compound. The two voltmeters 264 and 266 serve to generate liquid current signals, their amplitudes correspond to those of the peak amplitudes of the sawtooth flanks " Usually these DC signals are in the mostly equal to twice that from the control gate 224, in particular that of the Durchlaßtransaiission performing «.

One variety of Vergleieherschaltungen 270, 272, 274 and 276 are provided to the various by the peak volt meter 238, 240, 242, 264 and 266 for comparing signals generated and to ensure that their corresponding signals all aufvreisen the right proportions _e This first Vergleicherkreia 270 iflt connected to the left and right voltmeters 258 and 240 and is used to compare or average the left and right signals »

is

The second compressor circuit 272 / to the output of the forward voltmeter 242 and the output of the first! Comparator 270 connected. This is used to determine whether · if applicable the echoes are actually received from both strings of the centerline.

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When the signals from the two voltmeters 238 and 240 bei.da through the Eoho3 by dor Mittellini. 5 are generated, the output from the comparator 270 remains constant for any given head. whether the center line may have shifted aioii As a result, the output signal must be equal to the width of the Head corresponding to a signal.

For example, the direct current si, 3nal from the forward voltmeter 242 is 10 V. If the center line is completely centered and the echoes are reflected from the center line, the signals from the 1: in.cen and right voltmeters 238 and 240 are each 10 V · the mean of these both signals and the signal from comparator 270 is therefore 10V ₁ as is the case from forward voltmeter 242. As a result, the difference between these two is zero and the signal from comparator 272 is zero volts.

However, if the center line has shifted to the left or right, for example, the signal decreases to 8 V and the other signal rises to, for example, 12V. The middle from these signals riooh is always 10 V and is always equal to the voltage of the pass-through voltage 242. The result

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- 47 is that the output from comparator 272 is still. Indicates 0 V.

Let us assume the case that an echo received from the center line on one side and from a carget, e.g. a cerebral ventricle, on the other side * In this case, if the center line is centered, it always carries the first or valid echo signal still 10 Y. The error signal would, however, be equal to a smaller amount soin, namely 8 V. The mean of these signals has now decreased by 9 V and differs from the 10 V pass signal. This means that a corresponding difference signal (for example 1 V) is emitted by the comparator 272 »

The third comparator 274 is connected to the outputs of the forward voltmeter 242 and the right Fernseitonvoltmeter 264 connected, while the fourth comparator 276 with the outputs of the passage voltmeter 242 and deti left remote side voltmeter 266 is connected. These are used to match the pass signals with half of the left and right far side signals to compare. Obviously, if the transducers 26 and 28 are properly forward-transmitting work (for example, they are both correct with

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coupled to the head and aligned with one another) and if the transducers 26 and 28 also operate correctly according to the pulse echo method (d <, ii _{e in} addition to this coupling, the transducers send ultrasonic energy completely through the head and receive bonos from the far side), the through signals essentially equal to one half of the core side echo signals o The consequence is "then _f -if all these signals are the same, the system is working properly and the output signals from both comparators are equal to Hull,

A Hocli / Kiedrig Abnehiasr 278 (hi / lo piokoff) is connected to the outputs of the comparators 272, 274 and 276 A suitable alarm or indicator *, for example a bell, a buzzer and one lamp 203 are connected to the consumer 278 and indicate its possible operation on ₀

When operating this encephalograph 202, the user arranges two transducers 26 and 28 on the opposite ones

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1b4834.1

~ 49 -

Sites the Köpfst (ISS patients'iffriiti; the alarm means or the lieht 203 in activity is undertaken, the device benütssAcle operator only at the transducers 26 and until a valid attempt displayed 2S ₉ ο The user may then, the size of the optionally present Read off the shift of the center line directly from the measuring device 202.

. H. FiKCKE, d: pl.-in ·. H.

S. STAiSHt

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Claims (1)

16483A1 PATENT CLAIMS 1 · Ultrasonic testing device for determining the position of a acoustic targets within a workpiece _t marked duroh acoustically coupled to the workpiece * »ultrasonic transducer devices (26; 20); second devices (30, 34) which serve to excite the transducers (26; 20) in a first way, b * »i dpr ultrasonic energy into the workpiece in a first way to transfer the target (24). ^ gen will, un ^. in addition, a first electrical signal which is a function of the position of the target within the workpiece, and are able to excite the transducers in a second way, countering ultra-echo energy into the workpiece in a second way Target is transferred and ultimately serve a second to produce an electrical signal that has a function the location of the target (24) within the workpiece; and connected by a converter and a second device the arrangement that responds to the first and second signal « "speaks and a position signal (at 146; 164; 166) which is a Puncture of the position of the target is generated 109815/0298 BADORfGlNAL 2. Ultrasonic testing device according to claim 1, characterized in that two separate transducers (26; 28) are provided which are coupled to the workpiece at separate points; that the second devices (38; 44) do so serve to excite the first transducer according to the first type, such that the ultrasonic energy is transmitted in a first direction and that the first signal is a puncture the position of the target in this first direction, and the second devices (38; 44) also serve to energizing the second transducer of the second type such that ultrasonic energy is transmitted in a second direction and the second signal is a function of the location of the Targetβ in this second direction, and that said arrangement includes a signal comparator (148) for comparison of the first and second signals. 3. Ultrasonic testing device according to claim 2, characterized in that reference means (176) with the transducers (26; 28) and serve to provide a reference signal that is a function of a particular property of the workpiece is to be generated, and that devices (172) are provided which serve to generate the reference signal oit at least one " of the other signals see below. 109815/0298 4. Ultrasonic testing device, especially encephalograph for determining the position of the center line of the brain, characterized in that the transducers (26; 28) with the head (12) are acoustically coupled on both sides and transmit and receive ultrasonic energy in the head and that transmitters or transmitters (38; 44) are provided for evoking the first and second signals and Receiver (38; 44) also connected to transducers (26; 28) ^ are coupled and dependent on a first electrical signal of the sound energy transmitted according to the first type, the receiver depending on a second signal emits from the sound energy transmitted according to the second type; that an output is coupled to the receiver, responsive to the first and second signals and a Indicates the position of the center line there. 5. Ultrasonic testing device according to claim 4, characterized in that in the transmitters or transmitters (38; 44) * Means are provided that follow the ultrasonic energy a first type is transmitted in the head from the first side towards the center line in the form of a series of pulses, and that means in the receiver are responsive to the sound energy transmitted near the first type and the first signal 109815/0298 as a function of the distance between the first page and of the center line and that means in the display arrangement for comparing the first and second signals are provided such that the indication is a function of the location of the center line relative to the first page. 6. Ultrasonic testing device according to claim 4, characterized in that the transmitter or the transmitter (38; 44) intermittently excite the first transducer in such a way that the ultrasonic energy is transmitted according to this first type from the first transducer as a first series of pulses that is transmitted by the first side of the head extend to the center line and intermittently energize the second transducer, such that energy of the second type is transmitted from the second transducer as a second series of pulses traveling from the second side of the head to the center line, the receiver on the Echoes of the reflected pulses from the center line and serves to provide the rate signal as a function of the distance between the first side and the center line and the wide signal as a function of the distances between the second side and the center line EU, and that the output (146} 148; 150; 164; 166 | 170) means responsive to the first and second signals and the difference between the signals. 109815/0298 BAD ORfGiNAL 7. Ultrasonic testing device according to one of the preceding claims, characterized in that the converter of erete the first side against the center line during a first signal evaluation interval (gating interval) and that the second transducer is excited intermittently, and that the receiver connected to the transducers responds to the ultrasonic echoes reflected on the center line and one first row supplies signals delayed by time intervals, which are a function of the distance between the center line and the first side of the head and a second series of time interval delayed signals providing a Puncture the distance between the midline and the The second side of the head is that signal assemblies are coupled to the receiver and provide a pair of signals, the amplitudes of which are a function of the cell delays of these intervals, and that connected, to the connected- » Amplitude-modulated signals responsive Auegangseinriohtungen are provided that an indication of the location of the Deliver center line. 8. Ultrasonic testing device according to claim 7t characterized gates coupled to the buffers, to which the signals are placed, which are used to 109815/0298 The first gating interval is the first Series of tone signals with the first signal arrangement eu and during the second signal level interval the second series of signals with the second signal arrangement to couple »and that devices are provided which couple the output to the first and second signal arrangements in such a way that the output compares the signals of the first and second amplitude with one another. 9 «UltraeohallprtLfgerat naoh one of the preceding claims, characterized in that the reference arrangement (1T6) is coupled to the transducers (26; 28) and - »in first reference signal, which is a · function of dimension the head is »supplies, Ultrasonic testing device according to one of the preceding claims, characterized in that the first and second measuring devices (164-166) are connected to the first and second signal comparators (148; 150) to display the position of the center line. 11. Ultrasonic testing device naoh one of the preceding claims, characterized in that the first transmitter device is used to provide at least one additional 109815/0298 Sn erseugen, which is a function of the dimension dee Heads up the signal comparators old of the first transmitter and compare the relevant signal with at least one of the first and second signals and that Alarmetnricntungen (203) bit dea signal compensator connected bind and on the Yerglelona result of the signal speak to. 12. Ultrasohallprttfgerät according to claim 11, characterized ™ 0sfceQnssiofca "t _a da * το""advise the transmitter (36) · least a signal supplied we *, 4a · is ausgelöet in eiaer roll Yo-en by the topi JUactareli ttbmrtrafmwi Xatrcie and there · v * ni ** t * ne «in signal t, since the distant inergy reflected with« de «head is absorbed by the ▼«, and Λα » Blgnalkosjparatorea alt the tlnrlohtungett sue Tergleiohen * er signal are coupled mod that the dl · Alarselnrlohttmgen old of the signal cosparator (278) are coupled and respond to the comparison of these signals. ι. H. FINCKE, DiPL.-lN ·. H. i. iutam 10981 5/0298 BAD ORJGSMAt