WO2001013798A1

WO2001013798A1 - Active structure reader

Info

Publication number: WO2001013798A1
Application number: PCT/EP2000/006926
Authority: WO
Inventors: Eckard Glaser; Miroslaw Wrobel; Janet Grassmann
Original assignee: Sonem Gmbh
Priority date: 1999-08-21
Filing date: 2000-07-20
Publication date: 2001-03-01
Also published as: CA2376103A1; DE19939791A1; EP1204375A1

Abstract

The invention relates to an active structure reader for recording, in 3D-mode, information regarding unidentified structures. The active structure reader emits emission signals with any modulation function from an emitter and receives, in their complete information content, the signals which are reflected by an unidentified structure or which pass through the same and are attenuated due to absorption. This active structure reader can be used in any location where an unidentified structure is embedded in a medium, e.g. in the field of medicine for examining the human or animal body. The active structure reader is characterized in that acoustic modules having emitting and receiving elements are arranged in known positions with regard to one another so that their acoustic irradiation spaces and receive spaces overlap on the structure to be examined.

Description

ACTIVE STRUCTURAL READER

description

The invention relates to an active structure reader for acquiring information about unknown structures in 3D mode. The active structure reader sends transmission signals from any transmitter with any modulation function and receives the complete information content of the signals reflected by an unknown structure or weakened as a result of absorption. This active structure reader can be used wherever an unknown structure is embedded in a medium, e.g. in medicine when examining the human or animal body.

The examination of organs in the human body using ultrasound has long been known. Linear ultrasound heads are mostly used for this. These generally consist of individual piezo elements which are arranged next to one another and which successively emit a pulse with the same frequency on the organ to be examined. These individual pulses are reflected one after the other at acoustic boundary layers and the transit time of the pulses is measured. The depth of the boundary layer of an organ or a tumor is then determined from the transit time.

Since the unknown structure is only embedded in a homogeneous medium in exceptional cases, echo impulses occur at the inhomogeneities of the medium and therefore in most cases very fuzzy images, i.e. the pictorial representations from the echo pulses are more or less noisy. Extensive experience is therefore required when examining living tissues in order to determine the character of the structures to be examined.

The representations generated in this way are also only two-dimensional. A three-dimensional representation can only be generated from these signals if the structure to be examined is recorded from at least two different positions of the ultrasound heads and then a three-dimensional image is calculated. For this purpose, the linear ultrasound heads already described are designed to be pivotable, and the structure is scanned in layers by pivoting the ultrasound head. The Individual layers are then converted into a three-dimensional image using a computer. Under these conditions it is also possible to show different phases of movement of a structure such as a fetus. However, this method requires considerable computing effort and the images generated have the disadvantages already described.

Another disadvantage of this method is the low resolution of the structures shown. The resolution improves with increasing frequency. However, the penetration depth decreases with higher frequencies. This can only be increased by increasing the intensity. The contradictory properties that the resolution is improved with increasing frequency and the depth of penetration decreases with increasing frequency presents particular difficulties, since the intensity of the ultrasound cannot always be increased arbitrarily.

When examining human or animal bodies, a conventional transducer is often difficult and difficult to place near organs that are difficult to access. For example, the ultrasound scan of the prostate presents significant problems. Other, deeper organs are often difficult or impossible to detect.

The object of the present invention is therefore to overcome the disadvantages of the prior art and to propose an active detection device for the signals reflected on an unknown structure or weakened as it passes through it. The acquisition unit is intended to provide information for images with a high resolution and to allow unknown structures to be acquired and displayed in 3D mode. The acquisition unit for the information about an unknown structure in a medium should be designed in such a way that it can be placed as close as possible to an unknown structure or that it can as easily as possible the information about the location and size of an unknown structure receives. The object of the invention is achieved with an active structure reader according to independent claims 1 to 4.

In a first exemplary embodiment of an active structure reader for acquiring information about structures embedded in a medium in 3D mode, two acoustic modules are provided, of which the first acoustic module contains a plurality of transmitting elements with a coherent PA and the second acoustic module contains a plurality of Contain receiver elements with a coherent reception room. The acoustic modules are slidably arranged in at least three known non-colinear positions in a sensor unit. The two acoustic modules lie in relation to one another in such a way that the sound reinforcement area of one acoustic module and the reception area of the other acoustic module overlap as completely as possible in all positions of the acoustic modules in the area of an unknown structure lying between the acoustic modules. In each position of the acoustic modules, a transmit / receive cycle with any modulation function of the transmit signals is triggered between the acoustic modules, the transmit / receive cycle of the transmit signals being shorter than the cycle for changing the position of the acoustic modules.

The first acoustic module of this structure reader equipped with transmitter elements transmits a transmit signal to the structure in a first position of the acoustic modules to one another with any modulation function and a coherent PA system in the set frequency range, and the acoustic module with the receiver elements receives the echo signals or those that pass through the structure weakened by absorption signals with the complete information content for one dimension. The position of the two acoustic modules is then changed twice to each other and the send / receive cycle is repeated in each position. With three cycles, the complete information content is available for all three dimensions and a 3D representation can be made. In another embodiment of the invention of the active structure reader for capturing the information about structures embedded in a medium in 3D mode, the construction looks such that three acoustic modules are present, of which at least one and at most two acoustic modules contain a plurality of transmission elements , which form a coherent public address room, and the other acoustic module (s) is / are equipped with a large number of receiver elements, which form a coherent reception room. The acoustic modules are slidably arranged in at least two mutually known non-colinear positions in a sensor unit. The non-colinear positions can also be achieved by shifting only one acoustic module. The

Public address rooms of the transmission elements and the reception rooms of the receiver elements overlap as completely as possible in the area of the unknown structure in both positions of the acoustic modules and in each position of the acoustic modules a transmission signal with any modulation function is triggered and the signals caused by the transmission signal in the medium from the receiver elements detected. This transmission-reception cycle between the acoustic modules is repeated in each position of the acoustic modules with respect to one another with a transmission signal with any modulation function, the transmission-reception cycle being shorter than the cycle for changing the position of the acoustic modules.

With this active structure reader, the complete information content is available in one dimension in one cycle. A second cycle in a second position of the acoustic modules is required in order to capture and display the entire information in three dimensions.

In both exemplary embodiments, the acoustic modules are subjected to a change in position and the send / receive cycle is repeated in each position. Special conditions are therefore placed on the transmission signals. The send / receive cycle must be completed before the acoustic modules change position. The time from the start of the broadcast signal to the reception of all im Signals caused by the medium must therefore be shorter than the duration of the state of the acoustic modules in the current position.

In another embodiment, this active structure reader for capturing the information about structures embedded in a medium in 3D mode with three acoustic modules can also be designed in such a way that the acoustic modules are arranged in known positions relative to one another, so that the sound reinforcement areas of the transmitting elements and the reception areas of the receiver elements overlap as completely as possible in the area of the unknown structure. A transmission signal with any modulation function is triggered by the transmission elements on an acoustic module and the signals from the medium are detected by the acoustic modules with receiver elements. Instead of changing the position of one or more acoustic modules, the active elements can also be switched.

An active structure reader for recording the information about structures embedded in a medium in 3D mode, in which three acoustic modules are present and in which the position of the acoustic modules is not changed, one of the acoustic modules has a multiplicity of transmission elements with a contiguous one Public address room and the other acoustic modules a variety of receiver elements with a coherent reception room. The acoustic modules are arranged in known positions relative to one another in a sensor unit, and the sound reinforcement area of one acoustic module and the reception areas of the other acoustic modules overlap as completely as possible in the area of the unknown structure. A transmit / receive cycle with any modulation function is triggered between the acoustic modules. To

At the end of the transmit / receive cycle, the transmitter elements of one acoustic module are switched into receiver elements and the receiver elements of at least one of the other acoustic modules are switched into transmitter elements and the transmit / receive cycle is repeated. The send-receive cycle for the send signals must be shorter than the switchover cycle of the active elements of the acoustic modules. In another embodiment of the active structure reader of this type, in which no changes in the position of the acoustic modules are made, but in which two acoustic modules are equipped with transmitter elements and only one acoustic module has receiver elements, only the transmitter elements of an acoustic module have to be switched over to receiver elements. After switching the active elements, the second send / receive cycle is started. The transmission-reception cycle taking place between the acoustic modules also takes place here with a transmission signal with any modulation function, the transmission-reception cycle for the transmission signals being shorter than the switching cycle of the active elements of the acoustic modules.

In a further exemplary embodiment of the active structure reader according to the present invention, there are at least four acoustic modules, of which at least one acoustic module is a plurality of transmission elements with a coherent PA system and at least three acoustic modules are one

Have a large number of receiving elements with a coherent reception room or at least one acoustic module has a large number of receiving elements with a coherent reception room and at least three acoustic modules have a large number of transmitting elements with a coherent public address room. The acoustic modules are arranged in known positions relative to one another in a sensor unit. The sound reinforcement rooms of the acoustic modules with transmitter elements and the reception rooms of the acoustic modules with receiver elements overlap as completely as possible in the area of the unknown structure. The transmission elements send out a transmission signal with any modulation function and the receiver elements record the signals from the medium which are reflected on a structure to be detected or are weakened when passing through this structure.

In this embodiment, the entire information content about the structure can be acquired with a single cycle. This embodiment also has the decisive advantage that the signals can be acquired in real time. With a fast computer, the structure can be displayed in an extremely short time, so that for the first time the cardiologist and many technicians are given a means of directly following the actual processes.

Another decisive advantage is that it is not the transit time of the signals that is used to represent the unknown structures, but frequency shifts dependent on the distance of the structure from the transmitter, from which the coordinates of the structures are correlated between those modulated with any modulation function Transmitted signals and the received signals can be determined. The frequency and the length of the transmission signal modulated with any modulation function can be freely selected in the ultrasound area, depending on the area of application. Since the resolution and penetration depth are independent of the frequency, other criteria are important when choosing the frequency range, e.g. the lowest possible burden on a patient in medical applications.

In the active structure reader, the acoustic modules preferably have a curved surface and the transmitter elements and / or receiver elements can e.g. circular, cylindrical, elliptical or in another shape on these curved surfaces, so that in each case a coherent sound reinforcement room or a coherent reception room is created. The construction of the transmitting and receiving elements on the acoustic module can be chosen so that the public address and the receiving room remain largely independent of the frequency. The active area of the transmitting and receiving elements is therefore made as small as possible.

The equipment of the acoustic modules with transmitter and / or receiver elements is not tied to a size and shape of the transmitter and receiver elements. The transmitter and / or receiver elements can be arranged in different shapes, sizes and numbers on an acoustic module. In this way, the acoustic modules can be easily adapted to the respective task. Special arrangements can be made, for example, for examining the female breast by using smaller transmitting and receiving elements for the area of the mamilla and larger ones for the rest of the breast. The overlap of the sound reinforcement areas and reception volumes need not necessarily be contiguous for both areas, ie it is sufficient if this condition is met for each area of the breast.

The shape of the transmitter and receiver elements can be freely selected. The shape can be flat, spherical or otherwise. A particularly advantageous arrangement of the transmitter and / or receiver elements is formed when the active surfaces of the transmitting and recipient elements have a wabenfb ^'-shaped form and are closely abutted. However, the round shape of the transmitter and receiver elements creates a balanced characteristic.

Advantageously, the transmitter elements and receiver elements e.g. Piezo elements because they can be switched both as transmitter and receiver elements. Depending on the area of application, these can then be individually adapted. It is also possible to switch the transmitter and receiver elements on an acoustic module so that several coherent public address rooms or reception rooms are created. The acoustic modules can then be used both as transmitters and receivers.

According to the present invention, it is necessary for the acoustic modules to be arranged in a known position relative to one another, since it is only possible to triangulate the transmit and receive signals from their position relative to one another in order to determine the coordinates of the structures. Because when using the active structure reader according to the invention, the position of the structure is not determined from the transit times of the impulses. Since each acoustic module represents either a transmitter or a receiver during the send / receive cycle, no conditions are imposed on the signal length. To determine the coordinates of the structure, it is first determined at which times the transmit and receive signals correlate and then are off the path of the transmission signals from the transmitter via the reflection points to the respective receiver determines the coordinates of the reflection points. This takes advantage of the fact that, in the case of a transmission signal of any modulation, the reception signal has the same signal pattern as the transmission signal at the times when the transmission signal is reflected. From this, the ellipses or EUipsoids are determined, which are determined by the path of the transmission signal to the reflection points and further to the receivers, the transmitter and the receiver being in the focal points of the respective ellipses or EUipsoids. The spatial coordinates of the reflection points, ie the position of the unknown structure in the medium, result from the intersection points of the individual EUipsoids belonging to the receivers.

Another advantage of the inventive active structure reader is that, with a certain arrangement of the acoustic modules to one another, a shadow-free image of an unknown structure can be generated. The acoustic modules with the transmitter elements then "illuminate" the structure from different positions and the acoustic modules with the receiver elements "look" at these structures as from a "viewing window".

The user is also free to choose how many acoustic modules with transmitter elements and how many acoustic modules with receiver elements are arranged in an active structure reader. For a three-dimensional representation, either two acoustic modules with three transmit / receive cycles in three different arrangements of the acoustic modules that are not colinear to one another, or three acoustic modules with two transmit / receive cycles in two different arrangements of the acoustic modules are not colinear to each other. With three acoustic modules, the new position can also be generated by switching the transmitter elements and receiver elements. In order to obtain a three-dimensional representation in real time, at least one transmitter and three receivers or three transmitters and one receiver are required. Since the acquisition of information about the structure, the position of the transmitter and receiver elements is of crucial importance, it has proven to be advantageous to arrange the acoustic modules in a sensor unit so that they lie on an imaginary spherical surface the unknown structure is arranged so that the unknown structure lies approximately in the center of the imaginary sphere. With this arrangement of the acoustic modules, the triangulation is particularly simple and representation in polar coordinates is particularly favorable. However, any other form of arrangement of the acoustic modules can also be selected as long as the positions of the acoustic modules with respect to one another are known. If there are fewer than four acoustic modules, the positions of the acoustic modules must be changed with two successive transmit / receive cycles. Colinear positions of the acoustic modules must not be selected so that the information can be recorded for all three dimensions. The same effect is achieved if, as has already been described, depending on the arrangement of the transmitting and / or receiving elements on the acoustic modules, the active elements are switched over. If only a two-dimensional representation is required, this can be generated with the use of three modules with a send-receive cycle.

For medical examinations e.g. a spherical structure is produced on which there are a plurality of acoustic modules which are directed into the center of the spherical structure in which the organ to be examined or the unknown structure is located. This spherical structure can then e.g. be placed on the female breast with a contact agent to detect structures.

For examining the prostate, e.g. a special "saddle" can be constructed, or part of a "cylinder" is formed which is placed against the body to examine the kidney, liver or heart. These active structure readers can be of different sizes depending on the size of the patient. As is known from previous ultrasound practice, contact means between the acoustic modules and the medium, e.g. the human body. For medical

For example, the female breast can be examined in a container with water, in which the spherical structure, the sensor unit, is arranged with the acoustic modules. This examination method has the further advantage that the breast is weightless due to the buoyancy and is therefore not subject to deformation. The image of the breast can thus be much more meaningful than the representations from the previously known methods of ultrasound examination, in which the breast rests on the rib cage.

The range of use of the active structure reader can be expanded considerably if at least one acoustic module of the sensor unit can be manually inserted into the predetermined position of the individual acoustic modules in relation to one another. At this

Arrangement can e.g. in the case of a medical examination of an unknown structure in a human or animal body, an acoustic module is brought to the structure endoscopically or laparoscopically and the other acoustic modules can then be brought to this acoustic module either in a specific position relative to one another in a specific position. However, it is also conceivable that the acoustic modules are arranged individually outside or inside the body. The first step of the method then consists in detecting the positions of the individual acoustic modules relative to one another and entering them in the subsequent computer for the calculation of the coordinates, so that an error-free correlation and triangulation can be carried out. For this purpose, a special position transmitter can be provided and a special memory area for the coordinates of the acoustic modules can be present in the computer. The acoustic modules can then be attached to the most favorable locations in relation to the structures to be examined in the medium. It is always important that the sound reinforcement areas and the reception volume of the receiver elements overlap as completely as possible in the area of the unknown structure.

It is up to the user whether he switches the manually usable acoustic module as a single transmitter or as a single receiver, as a transmitter from further transmitters, as a receiver from further receivers or in succession in a different circuit in order to switch the cheapest way of displaying the structure determine. If, for example, piezo elements are used on the acoustic modules that are to be switched over in the individual acquisition cycles, it may be necessary to limit the length of the transmission signals.

With this active structure reader, a wide range of research areas are given a versatile instrument for the investigation of unknown structures that are embedded in a broadly inaccessible medium. There is an active one for the medical examination of organs, tumors, the movement of fetuses, heart valves and for the visualization of the different organs

Structure readers have been created, which not only make it possible to deliver clear images with a high resolution, but these images can also be displayed in real time, which is particularly important for the cardiologist.

This active structure reader is particularly important because the resolution is independent of the frequency of the transmission signal. For applications in medicine, there is the advantage that the frequency and the energy of the transmitted signal can be reduced, because possible late consequences of the previously used examination methods with ultrasound around 13 MHz are not yet known.

No real-time display is required because e.g. is a fixed immovable structure, the sensor unit can also be arranged in a minimal arrangement with e.g. two or three acoustic modules are used, the positions of which are changed relative to one another in order to record the complete information content of the structures.

The invention will be explained in more detail using a few exemplary embodiments. In the individual drawings, the same reference numbers mean the same or similar parts.

Show it: 1 shows a first embodiment of an active structure reader according to the present invention;

2 shows a second embodiment of an active structure reader according to the present invention; 3 shows a third embodiment of an active structure reader according to the present invention;

Fig. 4 shows an acoustic module with transmitter or receiver elements on a spherical

Surface;

5 honeycomb-shaped transmitter and / or receiver elements on an acoustic module; 6 oval transmitter and / or receiver elements on an acoustic module;

7 shows an acoustic module with a cylindrical surface;

8A and 8B acoustic module 2 with different transmitting and / or receiving elements in shape and size:

9 shows a hemispherical structure reader; 10 shows a saddle-shaped structure reader; and

11 shows an examination device with a structure reader according to the present invention.

1 shows a first exemplary embodiment of an active structure reader 8 according to the present invention. The active structure reader 8 for capturing information about structures 6 embedded in a medium in 3D mode consists of two acoustic modules 1, of which one acoustic module 1 contains a plurality of transmission elements 2, which form a coherent sound reinforcement room 3, and the other acoustic module 1 contains a plurality of receiver elements 4, which form a coherent reception room 5. The acoustic modules 1 are slidably arranged in at least three known positions that are not co-linearly to one another in a structure reader 8. The public address room 3 of the one acoustic module 1 and the reception room 5 of the receiver elements 4 of the other acoustic module 1 overlap as completely as possible in the area of an unknown structure 6 lying between the acoustic modules 1 in all positions AA, BB, and CC of the acoustic modules 1. In each position AA, BB, and CC of the acoustic modules 1 to each other, a transmission signal with any modulation function is triggered and the signals caused by the transmission signal in the medium are detected by the receiver elements 4. The send / receive cycle is completed before positions AA or BB are changed.

2 shows a second exemplary embodiment of an active structure reader 8 according to the present invention. The active structure reader 8 for capturing the information about structures 6 embedded in a medium in 3D mode in accordance with this exemplary embodiment has three acoustic modules 1, of which one acoustic module 1 contains a multiplicity of transmission elements 2, which form a coherent public address room 3, and the other acoustic modules are equipped with a plurality of receiver elements 4, which form a coherent reception room 5. The acoustic modules 1 are displaceably arranged in the structure reader 8 in at least two known positions A-A-A and B-B-B which are not co-linearly with one another. The public address rooms 3 of the one acoustic module 1 and the reception rooms 5 of the other acoustic modules 1 completely overlap in the area of the unknown structure 6 in both positions AAA and BBB of the acoustic modules 1 and in each position AAA and BBB of the acoustic modules 1 there is a transmission signal triggered with any modulation function. The signals caused by the transmission signal in the medium are detected by the receiver elements 5. In order to obtain a clear assignment of the transmission signals and the reception signals, the transmission-reception cycle of the transmission signals is shorter than the cycle for changing the position of the acoustic modules 1.

3 shows a third exemplary embodiment of an active structure reader 8 in accordance with the present invention. The active structure reader 8 for recording the information about structures 6 embedded in a medium in 3D mode in accordance with this exemplary embodiment consists of five acoustic modules 1, of which in this case two acoustic modules 1 contain a multiplicity of transmission elements 2 which form a coherent public address room 3 form, and the other acoustic modules 1 are with a plurality of receiver elements 4, one form coherent reception room 5, equipped. The acoustic modules 1 are arranged in a known position relative to one another in a structure reader 8. The public address rooms 3 of the one acoustic module 1 and the reception rooms 5 of the other acoustic modules 1 completely overlap in the area of the unknown structure 6. In this case, structure 6 is smaller than overlap 7 of FIG

Public address rooms 3 and reception rooms 5. The transmission elements 2 emit a transmission signal with any modulation function into the medium and the signals caused by the structures 6 in the medium are detected by the receiver elements 4. The transmitter elements 2 of at least one acoustic module 1 can be switched into receiver elements 4 and the receiver elements 4 of at least one acoustic module 1 can be switched into transmitter elements 2. The send / receive cycle for the send signals is shorter than the switchover cycle of the acoustic modules 1. The send / receive cycle must be ended before the switchover in order to achieve a clear recognition of structure 6 in the medium.

Further exemplary embodiments of the active structure reader 8 for acquiring the information about structures 6 embedded in a medium in 3D mode can consist of at least four acoustic modules 1. For the acoustic modules 1 there is at least one acoustic module 1 with a multiplicity of transmission elements 2, which each form a coherent PA system 3, or with a multiplicity of

Receiving elements 4 equipped, each forming a coherent reception room 5. With a single transmission-reception cycle of the acoustic modules 1 in the known positions relative to one another, the entire scope of information of a three-dimensional representation is recorded in real time. The acoustic module 1 with the transmission elements 2 emits a transmission signal with any modulation function, and the signals which are thereby caused on structures 6 in the medium are emitted by the acoustic modules 1 from the “sonicated” directions that correspond to the reception rooms 5. detected.

4 shows an acoustic module 1 with transmitter or receiver elements 2, 4 on a spherical surface. Using this arrangement is a simple solution for education a coherent PA room 3 or a coherent reception room 5. The acoustic module 1 can be made very small and can therefore be guided endoscopically or laparoscopically into the body as far as the organ to be examined, for example the prostate or the pancreas.

5 shows an acoustic module 1 with honeycomb-shaped transmitter and / or receiver elements 2, 4. These can be placed close together on the spherical surface of the acoustic modules 1. This creates a largely constant sound reinforcement room 3 or reception room 5.

6, oval transmitter or receiver elements 2, 4 are arranged on an acoustic module 1. 7 shows an acoustic module 1 with a cylindrical surface. Round transmitter or receiver elements 2, 4 are arranged on this cylindrical surface.

The figures 8A and 8B show acoustic modules 1 transmitter and / or receiver elements 2, 4, which have different shapes and sizes. 8A shows an acoustic module 1, on which the transmitter and / or receiver elements 2, 4 have different shapes and sizes. 8B, the acoustic module 1 has round transmitter and / or receiver elements of different sizes. With these arrangements it is possible e.g. to obtain a medium resolution from an organ and a higher resolution from certain areas of the organ. Since the shapes and sizes of the active elements essentially determine the resolution, these acoustic modules 1 are produced in accordance with the respective field of application.

The figures 9 and 10 show two exemplary embodiments for structure readers 8 according to the present invention, in which the acoustic modules 1 are each situated on an imaginary spherical surface in certain known positions relative to one another. In this exemplary embodiment, it could be a container which is filled with a contact means and into which the female breast is held. The main advantage here is that the breasts are boosted by the fluid becomes weightless and is therefore not subject to deformation. The resulting three-dimensional images, which are also available in low-noise quality, allow much better conclusions to be drawn about the individual structures than previously known recording methods.

FIG. 10 shows a saddle-shaped structural reader 8 which can be used in particular for examining the prostate. For this purpose, the “saddle” is placed between the patient's legs, so that the acoustic modules 1 are arranged between the anus and testicles. These acoustic modules 1 can only be populated with receiver elements 4, but this is not a condition. A single acoustic module 1 with eg only

Transmitting elements 2 can be arranged in a known position on the lower abdomen or, due to the small size of the acoustic modules 1, laparoscopically directly on the prostate. This results in an essential advantage of the structure reader 8 according to the present invention compared to the previously conventional arrangements for examining the prostate.

11 schematically shows a complete investigation arrangement in which the structure reader 8 according to the present invention can be used. The structure reader 8 consists in this case of an acoustic module 1 with transmitter elements 2 and four acoustic modules 1 with receiver elements 4 (left in the picture). The received signals, which arise in response to the transmission signal on the structures, are received by the receiver elements 4 and fed to a processing device 9. Here the transmit and receive signals are correlated and the coordinates of the structures 6 are determined by triangulation. The individual structures 6 are shown on the display 10.

Claims

claims

1. Active structure reader for capturing information about structures embedded in a medium in 3D mode, characterized in that two acoustic modules are present, one of which is a plurality of acoustic modules

Transmitting elements with a coherent public address room and the other acoustic module has a plurality of receiver elements with a coherent receiving room, that the acoustic modules are slidably arranged in at least three non-colinearly known positions in a sensor unit, that the public address room of the one acoustic

Module and the reception room of the other acoustic module in the area of an unknown structure lying between the acoustic modules overlap as completely as possible in all positions of the acoustic modules, and that in each position of the acoustic modules to each other between the acoustic modules, a transmit / receive cycle with any Modulation function can be triggered, the

Transmit-receive cycle of the transmit signals is shorter than the cycle for changing the position of the acoustic modules.

2. Active structure reader for capturing the information about structures embedded in a medium in 3D mode, characterized in that three acoustic Modules are available, of which at least one and at most two acoustic modules have a plurality of transmitter elements with a coherent sound reinforcement room and the other acoustic module (s) have a plurality of receiver elements, each with a coherent reception room, that the acoustic modules are slidably arranged between at least two non-colinearly known positions in a sensor unit, that the sound reinforcement rooms of one acoustic module and the reception rooms of the other acoustic modules overlap as completely as possible in the unknown structure in both positions of the acoustic modules and that in each position of the acoustic modules to each other between the acoustic modules a transmit

Reception cycle can be triggered with any modulation function, the transmission-reception cycle of the transmission signals being shorter than the cycle for changing the position of the acoustic modules.

3. Active structure reader for capturing the information about structures embedded in a medium in 3D mode, characterized in that there are three non-colinear acoustic modules, one of which is an acoustic module with a large number of transmission elements with a coherent PA and the other acoustic modules have a plurality of receiver elements with a coherent reception area, that the acoustic modules are arranged in known positions relative to one another in a sensor unit, that the

Public address room of one acoustic module and the reception rooms of the other acoustic modules in the area of the unknown structure overlap as completely as possible, that between the acoustic modules a send-receive cycle can be triggered with any modulation function, and that the transmission elements of the one acoustic module into receiver elements and the receiver elements of at least one of the other acoustic modules can be switched over to transmission elements, the transmission / reception cycle for the transmission signals being shorter than the switching cycle of the active elements of the acoustic modules.

4. Active structure reader for capturing the information about structures embedded in a medium in 3D mode, characterized in that there are three non-collinear acoustic modules, two of which are acoustic modules A large number of transmission elements, each with a coherent sound reinforcement room, and the other acoustic module have a plurality of receiver elements with a coherent reception space such that the sound reinforcement rooms of the two acoustic modules and the reception space of the other acoustic module overlap as completely as possible in the area of the unknown structure, that between the acoustic modules, a transmit-receive cycle can be triggered with any modulation function, and that the transmit elements of one of the acoustic modules can be switched into receiver elements, the transmit-receive cycle for the transmit signals being shorter than the changeover cycle of the active elements of the acoustic modules ,

5. Active structure reader for capturing the information about structures embedded in a medium in 3D real-time mode, characterized in that at least four acoustic modules are present, of which at least one acoustic module contains a plurality of transmission elements with a coherent PA and at least three acoustic Modules a variety of

Have reception elements with a coherent reception room or at least one acoustic module have a plurality of reception elements with a coherent reception room and at least three acoustic modules have a plurality of transmission elements with a coherent sound reinforcement room so that the acoustic modules are arranged in known, non-colinear positions to one another in a sensor unit that the public address rooms of the transmitter elements and the reception rooms of the receiver elements overlap as completely as possible in the area of the unknown structure and that a transmit / receive cycle with any modulation function can be triggered between the acoustic modules.

6. Active structure reader according to one of claims 1 to 5, characterized in that the surfaces of the acoustic modules have a curved shape, on which the transmitting and / or receiving elements are arranged in a circular, cylindrical, elliptical or other shape.

7. Active structure reader according to claim 6, characterized in that the transmitter and receiver elements have the smallest possible active area.

8. Active structure reader according to claim 7, characterized in that the transmitter and receiver elements have any shape.

9. Active structure reader according to claim 9, characterized in that the active surfaces of the transmitter and receiver elements have a honeycomb shape and are arranged close together on the acoustic module.

1 O.Active structure reader according to one of claims 6 to 9, characterized in that the acoustic modules contain transmitter and / or receiver elements in different shapes, sizes and / or numbers.

11. Active structure reader according to one of claims 2 to 5, characterized in that the transmitter and / or receiver elements can be switched so that several coherent public address rooms or reception rooms are available on an acoustic module.

12. Active structure reader according to one of claims 1 to 11, characterized in that the acoustic modules in known positions are mechanically firmly coupled to one another in such a way that they lie on an imaginary spherical surface which is arranged around the unknown structure such that the unknown Structure is arranged approximately in the center of the imaginary sphere.

13. Active structure reader according to one of claims 1 to 12, characterized in that at least one acoustic module can be used manually in a certain position of the acoustic modules to each other, and position sensors and memory are provided which determine the coordinates of the acoustic modules and save.

14. Active structure reader according to claim 13, characterized in that the manually usable acoustic module is equipped as the only acoustic module with transmitter elements or the only acoustic module with receiver elements.

15. Active structure reader according to one of claims 1 to 11, characterized in that all acoustic modules can be used manually in certain positions relative to one another, and position transmitters and memories are provided which determine the coordinates of the acoustic modules and store them.