Method and device for controlling a wave-emitting device

Abstract

Method and Device for Controlling a Wave-Emitting Device This disclosure relates to a device (10) and a method for controlling a wave-emitting device (20) to emit waves (W). The method comprises: driving the emitting device (20) by generating first electrical signals (SG1) through at least one first electrical connection (24a), producing first waves (W1) at the output of the emitting device and a first electromagnetic field (EM1); and producing a second electromagnetic field (EM2) opposite to the first electromagnetic field by generating, in at least one second electrical connection (24b), second electrical signals (SG2) with a current opposite to the current of the first electrical signals (SG1). Figure for the abstract: Figure 2

Description

Title of the invention: Method and device for controlling a wave emitting device Prior art

[0001] It is known to use a wave emitting device (also called a transmitter device) for communication, imaging or scanning purposes, for example in the field of medical imaging, radar, sonar, seismology, wireless communications, radio astronomy, acoustics and biomedicine. An example of an application of such a device is ultrasound imaging.

[0002] A transmitter device may comprise one or more transducer elements configured to generate waves in response to electrical excitation. The configuration and / or programming of such a transmitter device may vary depending on the desired characteristics (wavelength, power, etc.) and the purpose of the device.

[0003] Thus, an ultrasound emitting device (or ultrasound emitting device) may comprise one or a plurality of transducer elements configured to emit ultrasound waves, for various purposes, for example to perform ultrasound imaging.

[0004] As illustrated by way of example in [Fig.l], an ultrasonic transmitting device 2 can be controlled by means of electrical signals 1, the latter being able to be transmitted by means of one or more pulsers or linear amplifiers (not shown). These electrical signals 1 define waves transmitted to the transducer elements of the transmitting device 2, thus causing the emission of ultrasonic waves 3 in a given medium. The waves emitted in the medium can further be returned by the medium in the form of echoes which are received by one or more transducers of the device, these transducers being able to be the same or different transducers from those used in transmission. This response of the medium can thus be converted into electrical signals by the transducers used in reception.

[0005] In operation, such emitting devices, for example of the ultrasonic type, emit electromagnetic (EM) waves 4 ([Fig.l]). This electromagnetic radiation phenomenon results from the circulation of electrical signals transmitted to the emitting device to drive the transducers. The stronger the currents used, the greater the electromagnetic field generated by the emitting device is likely to be.

[0006] However, strong electromagnetic radiation is not always desirable. A strong electromagnetic field can in particular disturb the emitting device itself and / or electronic devices that may be located in the vicinity of the transmitting device, which can be critical in certain high-stress environments (hospitals, examination rooms, etc.).

[0007] In certain cases, it is necessary for a wave-emitting device to comply with a maximum threshold of electromagnetic emissions, this threshold being able to be defined in particular by a standard. Thus, there are various standards which impose authorized limit levels of electromagnetic emissions from electrical, scientific and medical devices, such as for example the standards IEC 60601-1-2, NF EN 55011 / CISPR 11 and IEC 61000-4-3.

[0008] In particular, the CISPR 11 standard (see for example edition 6.2 2019-01) defines the permissible limits (i.e. the "quasi-peak" / "quasi-peak" values ​​of the electromagnetic emission) for different frequency ranges used. Accordingly, the energy of an electric field emitted by a device must not exceed these limits in order to be declared as a device compliant with said standard. For example, Table 6 of the CISPR 11 standard concerns the electromagnetic radiation disturbance limits for Class A Group 1 devices, measured at a test site. In addition, Table 2 of the CISPR 11 standard concerns the disturbance voltage limits for Class A Group 1 devices, measured at a test site. A medical device, such as for example a system comprising an ultrasound probe, is typically Class A, as long as it is a non-domestic device.

[0009] In addition, the IEC 61000-4-3 / EN 61000-4-3 standard defines an electromagnetic compatibility (EMC) standard. Its parts 4-3 in particular concern the testing and measurement techniques used, as well as the immunity test to electromagnetic fields radiated at radio frequencies.

[0010] Wave emitting devices, such as ultrasonic devices for example, emit electromagnetic waves during operation by construction. Therefore, it is appropriate to limit the electromagnetic radiation generated by such devices, for example to comply with a maximum authorized threshold, while ensuring satisfactory performance of these devices during operation. Disclosure Statement

[0011] One of the objects of the present disclosure is to solve at least one of the problems or deficiencies described above.

[0012] In particular, an object of the present disclosure is to limit the electromagnetic emissions of a wave emitting device, for example an ultrasonic emitting device, while ensuring the latter has satisfactory performance, in terms for example of spectral response and / or delivered wave energy (or power).

[0013] In particular, an object of the present disclosure is to design a high-performance ultrasonic emitting device, generating a minimum of electromagnetic emission in operation while presenting a complexity of design, manufacture and of limited use.

[0014] To this end, according to a first aspect, the present disclosure relates to a method for controlling a transmitting device for transmitting waves, said method comprising: - controlling the transmitting device by generating first electrical signals, called useful signals, through at least a first electrical connection, producing first waves at the output of the transmitting device and a first electromagnetic field; and - production of a second electromagnetic field opposite to the first electromagnetic field by generation in at least a second electrical connection of second electrical signals, called auxiliary signals, of current opposite to the current of the useful signals.

[0015] The method according to the disclosure may include other features which may be taken separately or in combination, in particular among the following embodiments which are presented for illustration purposes only and may be combined or associated unless otherwise stipulated.

[0016] According to one example, the useful signals are generated by a first electrical power source and the auxiliary signals are generated by a second electrical power source.

[0017] According to one example, the first and second electrical power sources are separate sources or common sources.

[0018] According to one example, a group of electrical connections are connected to the transmitting device, the method comprising: - allocation of the electrical connections of the group, to serve respectively either as the first electrical connection or as the second electrical connection.

[0019] According to one example, the assignment is carried out according to a random time sequence.

[0020] According to one example, the assignment is carried out according to a predefined time sequence.

[0021] According to one example, said assignment is configured so that an electrical connection serves as a first and second electrical connection at different times.

[0022] According to one example, the generation of the auxiliary signals is controlled so that one electrical connection is used as a second electrical connection and not as a first electrical connection.

[0023] According to one example, said at least one second electrical connection (24b) in which the auxiliary signals (SG2) are generated is one or more electrical connections other than said first electrical connection.

[0024] According to one example, the generation of the useful and auxiliary signals causes the circulation of opposite currents II and I2 in respectively said at least one first and second electrical connections, said useful and auxiliary signals being controlled over time so that the algebraic sum of currents II and 12 is less than current II.

[0025] According to one example, the useful and auxiliary signals are controlled over time so that the algebraic sum of the currents II and I2 tends towards, or is substantially equal to, zero.

[0026] According to one example, the useful and auxiliary signals are generated simultaneously.

[0027] According to one example, the useful and auxiliary signals are generated during periods respective emission currents which are separated in time by a sufficiently short delay so that the sum of currents II and I2 is less than II.

[0028] According to one example, the first waves are emitted at a wavelength X, said at least one first electrical connection being spaced from said at least one second electrical connection by a distance D such that D < X / 10.

[0029] According to one example, the transmitting device comprises a blocking means, the method comprising: - blocking, by the blocking means, of at least part of the emission, by the transmitting device, of second waves, called auxiliary waves, in response to the auxiliary signals.

[0030] According to one example, the blocking means comprises an impedance load, connected to said at least one second electrical connection, obstructing the auxiliary signals.

[0031] According to one example, said first waves produced at the output of the emitting device are acoustic waves.

[0032] According to one example, said method is applied to ultrasound medical imaging.

[0033] According to a second aspect, the present disclosure may involve a computer program comprising instructions which, when the program is executed by a computer, cause the implementation of the method according to the first aspect. In particular, the different steps of the method according to the first aspect may be defined by computer program instructions.

[0034] Such a computer program may use any programming language or equivalent, and may be in the form of source code, object code, or code intermediate between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0035] According to a third aspect, the present disclosure relates to a recording medium (or information medium), readable by a computer (or a processor), on which a computer program according to the second aspect of the present disclosure is recorded.

[0036] On the one hand, the recording medium can be any entity or device capable of storing the program, such as at least one volatile and / or non-volatile memory volatile. For example, the medium may include a storage medium, such as rewritable non-volatile memory, ROM memory, CD-ROM or microelectronic circuit type ROM memory, or magnetic recording medium or hard disk. This memory may, for example, include graphics card (or video card) memory, this type of memory being capable in particular of processing image data (or video data).

[0037] Furthermore, this recording medium may also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other means. The computer program according to the present disclosure may in particular be downloaded using a wired or non-wired network, of local type or not (Bluetooth® for example, Wi-Fi, Ethernet, Internet, 4G, 5G or others).

[0038] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to perform or to be used in performing the method in question.

[0039] According to a fourth aspect, the present disclosure relates to a control device for controlling a wave emitting device, this control device being configured to implement the method of the first aspect of the present disclosure.

[0040] According to one example, the control device comprises a memory associated with a processor, this memory comprising a computer program according to the present disclosure.

[0041] According to one example, the present disclosure relates to a control method for controlling a wave emitting device, said control device comprising: - control module configured to control the transmitting device by generating first electrical signals, called useful signals, through at least a first electrical connection, producing first waves at the output of the transmitting device and a first electromagnetic field; and - production module configured to produce a second electromagnetic field opposite to the first electromagnetic field by generating in at least a second electrical connection second electrical signals, called auxiliary signals, of current opposite to the current of the useful signals.

[0042] The processing device may have functionalities that correspond to the steps (or operations) of the method according to the first aspect of the present disclosure. In particular, the different embodiments mentioned in the present disclosure in relation to the method of the present disclosure as well as the associated advantages may be applied in an analogous manner to the control system (and vice versa).

[0043] By implementing the present disclosure, it advantageously becomes possible to limiting the electromagnetic radiation emitted by an emitting device in operation, such as an ultrasonic device for example, while ensuring the latter satisfactory performance, in terms for example of spectral response and / or wave energy (or power) delivered in or towards an area of ​​interest. It is thus advantageous to limit the level of electromagnetic emissions with minimal impact (ideally no impact) on the desired operating performance of the emitting device. The present disclosure thus allows optimal use, i.e. with emission of waves useful for the study of the region of interest concerned, with minimal disturbance of the external environment and / or of the emitting device itself.

[0044] To do this, a second electromagnetic field is produced by generating auxiliary electrical signals (or non-useful signals). This second field opposes the first electromagnetic field resulting from the first electrical signals used to produce the useful waves, which makes it possible to attenuate, or even cancel, the second electromagnetic field and therefore to minimize the total electromagnetic field produced by the emitting device.

[0045] The production of this second EM field can be advantageously implemented in an existing emitting system or device, such as an ultrasonic device, without requiring additional devices and / or structural modifications to the existing system or device. The complexity and cost of implementing the method can therefore be limited.

[0046] The characteristics and advantages of the disclosure will appear more precisely on reading the description which follows, given solely as a non-limiting example, and made with reference to the appended figures. In particular, the examples illustrated in the figures can be combined with each other, except in the case of obvious inconsistency. Brief description of the figures

[0047] Other characteristics and advantages of the present disclosure will emerge from the description of the non-limiting exemplary embodiments of the present disclosure set out below, with reference to the appended figures 1 to 11, in which:

[0048] [Fig.l] schematically represents the behavior of an ultrasonic emitting device of the prior art according to an example;

[0049] [Fig.2] schematically represents a control device, and more generally a transmitter system, for controlling a transmitter device, according to exemplary embodiments of the present disclosure;

[0050] [Fig.3] schematically represents an implementation of the transmitter system of [Fig.2], according to exemplary embodiments of the present disclosure;

[0051] [Fig.4] schematically represents the control device of [Fig.2], according to examples of embodiments of this disclosure;

[0052] [Fig.5] schematically represents the transmitter system of [Fig.2], according to exemplary embodiments of the present disclosure;

[0053] [Fig.6] schematically represents in the form of a diagram the steps of a control method implemented by a control device, according to exemplary embodiments of the present disclosure;

[0054] [Fig.7] schematically represents the control of the transmitting device of [Fig.2], according to exemplary embodiments of the present disclosure;

[0055] [Fig.8] schematically represents the control of the transmitting device of [Fig.2], according to exemplary embodiments of the present disclosure;

[0056] [Fig.9] schematically represents a blocking element for at least partially blocking auxiliary waves at the output of the transmitting device of [Fig.2], according to exemplary embodiments of the present disclosure;

[0057] [Fig. 10] schematically represents the control device of [Fig.2], according to exemplary embodiments of the present disclosure; and

[0058] [Fig. 11] schematically represents a power source configured to deliver auxiliary signals, according to exemplary embodiments of the present disclosure. Description of the embodiments

[0059] A wave emitting device, also called a transmitter device, is configured to emit waves, of the ultrasonic or other type, at the output in response to excitation signals, called first signals. These signals inherently generate electromagnetic (EM) radiation which is added to the useful waves emitted at the output of the transmitter device in an area of ​​interest. Such EM radiation can be a source of disturbance and therefore undesirable.

[0060] The constraints and / or problems mentioned above therefore require compromises to be made and / or certain characteristics of such an ultrasonic emitting device to be limited in order to guarantee good performance and an acceptable level of electromagnetic emission. These constraints and / or problems may also make it difficult to qualify such a wave emitting device according to current standards.

[0061] The present disclosure relates in particular to methods and devices for controlling a wave-emitting device, of the ultrasonic or other type. The present disclosure proposes to respond in particular to the problems and constraints previously described by causing the production of a second electromagnetic field which opposes the first magnetic field resulting from the circulation of the first signals.

[0062] The method according to examples of the present disclosure comprises: - controlling the transmitting device by generating first electrical signals, called useful signals, through at least a first electrical connection, producing first waves at the output of the transmitting device and a first electromagnetic field; and - production of a second electromagnetic field opposite to the first electromagnetic field by generation in at least a second electrical connection of second electrical signals, called auxiliary signals, of current opposite to the current of the useful signals.

[0063] It is thus advantageously possible to limit the electromagnetic radiation emitted by the emitting device, while preserving the performance of said device, in particular in terms of wave energy (acoustic energy or other) delivered at the output of the device.

[0064] Methods and devices for controlling a transmitting device will now be described according to particular embodiments of the disclosure with joint reference to Figures 2 to 12. Unless otherwise indicated, elements common or similar to several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again, for the sake of brevity.

[0065] The terms "first(s)", "second(s)", etc.) are used in this document by arbitrary convention to enable different elements (such as operations, devices, etc.) implemented in the embodiments described below to be identified and distinguished.

[0066] The examples of implementation of the present disclosure are described below in the context of an ultrasonic emitting device. It should be noted, however, that the concept of the present disclosure is not limited to ultrasonic emissions but can be applied more generally to other types of waves that can be emitted by a emitting device in response to electrical signals.

[0067] The concept of the present disclosure is not limited to imaging (ultrasound or other type) but can be implemented in other applications, which do not necessarily involve the production of images but another use of the waves, allowing for example the analysis or study of an area of ​​interest, as described below in particular examples.

[0068] As previously indicated, the present disclosure relates in particular to a control method implemented by a control device, and more generally by a transmitter system, as well as such a transmitter device. [Fig. 2] schematically represents a transmitter device 20 according to examples of the present disclosure. It is assumed in the following that the device 20 is an ultrasonic transmitter device (or ultrasonic transmission device) configured to emit ultrasonic waves at the output ultrasonic waves W1 (or ultrasonic pulses, or ultrasonic beams) in response to first electrical signals SGI, called useful signals. As illustrated in [Fig.2], these ultrasonic waves W1 are for example emitted in a zone of interest M during an emission operation. This zone M can include a medium or object that one wishes to analyze or study.

[0069] A control device 10 is configured to transmit the electrical signals SGI (useful signals) to the ultrasonic emitting device 20 in order to cause the emission of the ultrasonic waves W1. The useful signals SGI thus emitted make it possible to control the ultrasonic waves W1 emitted by the emitting device 20. These waves W1 are considered as useful waves in the sense that they are generated under the control of the device 10, or used, to analyze the area of ​​interest M, for example to analyze waves emitted in return by the area of ​​interest when it is insonified. The electrical signals SGI define the ultrasonic waves W1 emitted in the medium M by the emitting device 20.

[0070] To do this, the control device 10 is electrically coupled (or connected, or associated) to the transmitting device 20 by means of electrical connections 24 (comprising the connections 24a and 24b as described below). The control device 10, the transmitting device 20 and the electrical connections 24 form a wave transmitting system denoted S Y1 ([Fig.2]). According to one example, the electrical connections 24 are part of the transmitting device 20.

[0071] The electrical connections 24 may have various arrangements and shapes. They may thus be electrical tracks formed on an electronic card and / or one or more electrical cables (for example of the coaxial type).

[0072] According to one example, each first electrical connection 24a is included in a first electrical cable and each second electrical connection 24b is included in a second electrical cable, different from the first cable. These two cables can then be arranged close to each other over all or part of their respective lengths. The positioning of the electrical connections 24a and 24b in separate cables advantageously makes it possible to ensure good flexibility of the assembly and to reduce the complexity of design and manufacturing, and therefore reduce manufacturing costs. To ensure that the two cables are kept close together, the latter can be fixed together by means of a mechanical assembly, for example at a connector (for example the connector 23 illustrated [Fig. 3]) and / or the emitting device 20 where the electromagnetic radiation is particularly significant.The positioning of at least one electrical connection 24a at the connector and / or the transmitting device 20 advantageously makes it possible to improve the ergonomics and aesthetics of the assembly.

[0073] The control device 10 is configured to control the transmitter device 20 by generation of useful signals SGI, through at least a first electrical connection 24a, causing the production of first ultrasonic waves W1 at the output of the emitting device 20. The circulation of these electrical signals SGI through the first electrical connection(s) 24a naturally produces a first electromagnetic field EM1 in the vicinity of the emitting device EM1.

[0074] The characteristics of the electrical signals SGI may vary depending on the case. Generally, these signals SGI may comprise a current II flowing in the first electrical connection(s) 24a.

[0075] As illustrated in [Fig.2], the transmitting device 20 comprises in this example a plurality of ultrasonic transducer elements 22 configured to transmit ultrasonic waves W1 (or ultrasonic pulses, or ultrasonic beams) in response to the useful signals SGI. Thus, each transducer element 22 is capable of converting, into ultrasonic waves W1, useful signals SGI supplied by the control device 10 via the electrical connections 24a. Each electrical connection 24a can thus constitute a transmission channel to a transducer element 22. The useful waves W1 are thus transmitted in the area of ​​interest M during a transmission operation. The nature of the useful waves W1 generated is a function of the useful signals SGI delivered by the control device 10.

[0076] These transducer elements 22 can be arranged in various suitable ways, for example in a line, a matrix, or in a network of transducers or any other configuration suitable for the intended use. The transducer elements 22 are shown in [Fig.7] according to a particular example.

[0077] Note that the transducer elements 22 (or other transducer elements of the transmitter device 20) may optionally also be configured to receive ultrasonic signals from the area of ​​interest M during a reception operation, for example in response to the useful waves W1, although variants according to which the transmitter device 20 operates only in transmission are also possible. In examples where the transmitter device 20 is configured to transmit waves W1 but not to receive waves from the medium M, another receiver device may be used.

[0078] As illustrated in [Fig.2], the control device 10 is further configured to produce a second electromagnetic field EM2, opposite to the first electromagnetic field EM1, by generating in at least one second electrical connection 24b second electrical signals SG2, called auxiliary signals. These auxiliary signals SG2 (also called non-useful signals, or non-functional signals, or masking signals) comprise an opposite current 12, that is to say a current which is opposite (or inverse) to the current II of the useful signals SGI.

[0079] For example, at least one second electrical connection 24b, other than the first electrical connections 24a, can be used to deliver to the transmitter device 20 the auxiliary signals SG2, the current 12 of which is opposite to the current II of the useful signals SGI. The circulation of this opposite current 12 in the second electrical connection(s) 24b leads to the production of the electromagnetic field EM2 which opposes the electromagnetic field EM1. To do this, the signals SGI and SG2 can be generated simultaneously or at close instants in time as described below in exemplary embodiments.

[0080] In the present disclosure, a means or a characteristic (a signal, a wave, etc.) is described as “auxiliary”, or even “non-functional” or “non-useful” (or even “dummy” in English), to indicate that its purpose is not aimed at analyzing a zone of interest M. For example, the auxiliary signals SG2 described in the different examples of the present disclosure are not signals used to analyze the medium M. These auxiliary signals SG2 aim to attenuate the electromagnetic field emitted by the emitting device 20 (or more generally by the system SY1) and not necessarily to produce waves that can be used for analyzing the medium M considered.

[0081] In the present disclosure, currents are considered to be opposite (or reverse) if they flow substantially in opposite (or reverse) directions or senses. For example, it is assumed that current II flows in each first electrical connection 24a in the same first direction, for example from the control device 10 to the transmitter device 20, and that current I2 flows in each second electrical connection 24b in a second direction opposite (or reverse) to the first direction, for example from the transmitter device 20 to the control device 10.

[0082] According to one example, the electrical connections 24 are arranged so that the first and second electrical connections 24a and 24b extend along an identical or substantially identical electrical path, between the control device 10 and the transmitting device 20. According to one example, the electrical connections 24a and 24b are parallel, or substantially parallel, to each other.

[0083] By nature, the electromagnetic fields EM1 and EM2 are each the result of a respective electromagnetic force that can be applied to any electrical charge in the vicinity of the emitting device 20. These electromagnetic fields each comprise an electric field and a magnetic field. As illustrated in [Fig.2], the electromagnetic field EM1 resulting from the useful signals SGI comprises an electric field El and a magnetic field B1 while the electromagnetic field EM2 resulting from the auxiliary signals SG2 comprises an electric field E2 and a magnetic field B2.

[0084] The electromagnetic fields EM1 and EM2 are opposite insofar as the magnetic fields B1 and B2 oppose each other and the electric fields El and E2 oppose each other.

[0085] In the present disclosure, two given fields (electric and / or magnetic) are considered to be opposite when their respective forces apply in opposite directions (or orientations) in the same region of space. These fields thus have the same direction at a point but in opposite directions. The respective intensities of the fields considered may however be identical, close or different at this point depending on the case.

[0086] By producing a second electromagnetic field EM2 opposite to the first electromagnetic field EM1, it is advantageously possible to mask, at least in part, the electromagnetic field EM1 resulting from the circulation of the useful signals SGI. In other words, this advantageously makes it possible to attenuate or limit, or even cancel, the total electromagnetic field, denoted EM3, produced by the emitting device 20, or more generally by the emitting system SY1.

[0087] The control device 10 may in particular comprise electrical power sources 16 ([Fig.2]) configured to deliver the electrical signals SGI and SG2 respectively through the electrical connections 24a and 24b. These power sources 16 may for example be or comprise electronic pulsers (more simply called “pulsers”) and / or linear amplifiers.

[0088] The emitting device 20 may for example take the form of an ultrasound probe (for example an ultrasound probe).

[0089] According to one example, the control device 10 and the transmitter device 20 are separate devices. According to variants, all or part of the control device 10 may be implemented in the transmitter device 20.

[0090] Generally speaking, the ultrasonic system SY1, and more precisely the control device 10, the electrical connections 24 and the emitting device 20, can be stationary or mobile.

[0091] According to one example, the control device 10 and the transmitting device 20 form a single device, stationary or mobile as the case may be.

[0092] As illustrated in [Fig.2], the control device 10 comprises in this example a processor 12 and a memory 14. The control device 10 is configured to control the transmitter device 20 by generating electrical signals, namely the useful signals SGI and the auxiliary signals SG2 as previously described.

[0093] In examples, the processor 12 and memory 14 may be incorporated into the control device 10 illustrated in [Fig.2] or may be incorporated into a computer or computing device communicatively linked thereto.

[0094] The memory 14 can store in the form of a computer program PG1 instructions defining the steps of the control methods as described in the present disclosure. In this respect, the memory 14 constitutes a recording medium (or information medium) conforming to particular embodiments, readable by the control device 10, and on which is recorded a computer program PG1 conforming to particular embodiments. This computer program PG1 comprises instructions for executing the steps of a control method, particular embodiments of which are described in the present disclosure. The processor 12 is thus configured to execute the instructions of the computer program PG1 in order to carry out steps of the control method.

[0095] Depending on the configuration and the type of computer device considered, the memory 14 may be volatile (such as RAM), non-volatile (such as ROM, flash, EEPROM, etc. or any other storage device and / or computer-readable medium as described below) or a combination of both. The memory 14 may, for example, be managed in DMA mode (for “Direct Memory Access”). The memory 14 used by the control device 10 may, for example, comprise all or part of a graphics card (or video card) memory, this type of memory being in particular capable of processing and / or sending image data that can be used to display one or more images on a display screen (or unit).

[0096] The control device 10 may take the form of various suitable computer means (such as, for example, workstation, computer, server, etc.) comprising all or part of the elements described above as well as possibly other elements not mentioned.

[0097] The transmitter device 20 may be an ultrasound imaging device, for example in the medical field or in any other fields requiring the emission of ultrasound waves. The same applies to the transmitter system SY1 as a whole. The ultrasound images capable of being generated by the system SY1 may either be analyzed in real time, for example by a user or an algorithm, and / or an artificial intelligence module, or produced and / or analyzed later and / or in a location other than that in which the system SY1 is located.

[0098] The system SY 1 may be a medical ultrasound system. Similarly, the transmitter device 20 may be a medical ultrasound probe.

[0099] The SY 1 system can however be implemented in applications other than imaging and in fields other than medical. More generally, the SY 1 system can be implemented in applications of various natures, for example for communication, imaging or scanning purposes, for example in the field of medical imaging, radar, sonar, seismology, materials studies, wireless communications, radio astronomy, acoustics and biomedicine.

[0100] Thus, the area of ​​interest M ([Fig.2]) observed, analyzed or probed by means of the useful waves W1 can be of various natures depending on the case. It can be for example metals, tissues of living beings (in particular human tissues or animal tissues), or even mineral structures (gravel, volcano, mapping of a soil, for example of the seabed, etc.).

[0101] [Fig. 3] schematically represents a non-limiting exemplary embodiment of the transmitter system S Y1 as previously described with reference to [Fig. 2], namely in this case an ultrasound imaging system. In this example, the control device 10 is included in the body of a control station, the latter being further provided with a control interface and a display device. The transmitter device 20 takes for example the form of an ultrasound probe, connected (or coupled) in a communicative manner with the control device 10 via a connection cable 25 comprising the electrical connections 24. A connector 23 can serve as an interface connecting the electrical connections 24 (or more generally the connection cable 25) to the control device 10.

[0102] The transmitter system SY1 can be configured to produce an ultrasound image of various types, for example a B-mode image of the medium M (B-mode image displayed in grayscale), a so-called Doppler image illustrating the movements of fluids in the observed medium, and / or an image showing a mechanical characteristic of the medium (for example elastography image data obtained using shear waves (“ShearWave™ Elastography”)). According to one example, the electrical signals SGI transmitted by the control device 10 thus cause the transmitter device 20 to emit ultrasonic compression waves W1 generating shear waves in a medium M.

[0103] As shown in [Fig.4] according to one embodiment, the processor 12 of the control device 10, controlled by the computer program PG1 ([Fig.2]), can implement modules (or units), namely a control module MD2 and a production module MD4.

[0104] More specifically, the control module MD2 can be configured to control the transmitter device 20 by generating first electrical signals SGI, called useful signals, through at least a first electrical connection 24a, producing first waves W1 at the output of the transmitter device 20 and a first electromagnetic field EM1.

[0105] The production module MD4 can be configured to produce a second electromagnetic field EM2, opposite to the first electromagnetic field EM1, by generation in at least one second, other, electrical connection 24b of second electrical signals SG2, called auxiliary signals, of current I2 opposite to the current II of the useful signals SGI.

[0106] The configuration and operation of the modules MD2 and MD4 of the control device 10 will appear more precisely in the exemplary embodiments described below. after with reference to the figures. The MD2 and MD4 modules as shown in [Fig.4] represent only a non-limiting example of implementation of the invention.

[0107] Generally, for each step of the control method of the present disclosure, the control device 10 of the disclosure may comprise a corresponding module configured to carry out said step (and vice versa).

[0108] [Fig. 5] schematically represents an example of implementation of the transmitter system SY1 previously described with reference to FIGS. 2-4. In this example, the control device 10 comprises a first electrical power source 16a and a second power source 16b configured to generate respectively the useful signals SGI and the auxiliary signals SG2. The useful signals SGI are delivered to the transmitter device 20 via an electrical connection 24a and the auxiliary signals SG2 are delivered to the transmitter device 20 via respectively two electrical connections 24b.

[0109] The number of electrical connections 24a and 24b can be adapted according to the case, in particular according to the number of transducer elements 22 to be supplied in the transmitter device 20. More generally, the system SY 1 can use N electrical connections 24a and M electrical connections 24b to deliver the signals SGI and SG2 respectively, where M and N are integers greater than or equal to 1.

[0110] The power sources 16a and 16b may each comprise, for example, at least one electronic pulser and / or at least one electrical signal generator.

[0111] The use of these power sources 16a and 16b advantageously makes it possible to generate the desired useful waves W1 while carrying out an active attenuation of the total electromagnetic field EM3 of the emitting device 20, and more generally of the system SY1. The auxiliary signals SG2 generated by the power source 16b in fact induce an electromagnetic field EM2 which opposes, and therefore at least partly masks, the electromagnetic field EM1 resulting from the circulation of the useful signals SGI.

[0112] According to an example illustrated in [Fig. 5], the electrical connections 24a and 24b are formed in a coaxial cable 34 electrically connecting the control device 10 to the transmitting device 20. Conducting wires 35 within the coaxial cable 34 can be used as electrical connections 24a and 24b. These conducting wires 35 can optionally be covered or protected by a shielding layer 36 against electromagnetic emissions, so as to advantageously attenuate the electromagnetic radiation even more effectively. In one example, the electrical connections 24 are devoid of electromagnetic shielding, which advantageously ensures good flexibility of the assembly (thinner cable), facilitates the manufacture of the assembly and reduces the manufacturing costs and the materials used. In particular, the absence of shielding facilitates the implementation of the system during manufacturing, operational use and end-of-life recycling.

[0113] According to one example, the transmitter device 20 comprises a plurality of piezoelectric transducers 22 (FIGS. 2 and 5), each first electrical connection 24a connecting a first electrical power source 16a to a piezoelectric transducer 22. Several piezoelectric transducers 22 may share the same power source 16a or be powered by separate power sources 16a. The useful signals SGI are thus transmitted in each first electrical connection 24a to cause the generation of the first waves W1 by the piezoelectric transducers 22.

[0114] According to one example, the power supply sources 16a and 16b are separate sources. According to another example, the power supply sources 16a and 16b are common sources, in other words at least one power supply is used to generate both the SGI and SG2 signals.

[0115] According to one example, the power source 16a is internal to the control device 10 while the power source 16b is external to the control device 10 and operates under the control of said control device 10.

[0116] According to one example, the electrical power sources 16a and 16b are current power sources. According to another example, the power sources 16a and 16b are voltage power sources, which advantageously makes it possible to use voltage generators which are generally less complex (in design, manufacturing, etc.) than current generators. This also advantageously makes it possible to precisely control the electrical behavior of the system and thus to optimize its reliability. In the case where a current generator is used, it is desirable to check that excessive electrical stress (in particular too high a voltage) is not applied to the circuit.

[0117] Embodiments of the disclosure control method are now described with reference to [Fig. 6]. In these examples, the control method is implemented by the transmitter system SY1, and more precisely by the control device 10, as previously described (Figures 2-5). To do this, the control device 10, cooperating with the transmitter device 20, can execute the computer program PG1.

[0118] During a step S2, the transmitter device 20 is controlled by generating first electrical signals SGI, called useful signals, through at least one first electrical connection 24a. These first electrical signals SGI produce first waves W1 at the output of the transmitter device 20 as well as a first electromagnetic field EM1 (FIGS. 2 and 4).

[0119] During a step S4, a second electromagnetic field EM2, opposite to the first electromagnetic field EM1, is produced by generation of second electrical signals SG2 in at least one second electrical connection 24a other than the first electrical connection(s) 24b. These second signals SG2, called auxiliary signals, are of current 12 opposite to the current II of the useful signals SGI.

[0120] The method of the present disclosure advantageously makes it possible to limit the electromagnetic radiation EM3 globally emitted by the emitting device 20 (and more generally by the emitting system SY1), while ensuring satisfactory performance for the emitting device 20, for example in terms of spectral response and / or acoustic energy (or power) delivered in the area of ​​interest M. It is thus advantageous to limit the level of electromagnetic emissions with minimal impact (or even no impact) on the desired operating performance of the emitting device 20. The method thus allows optimal use, i.e. with emission of useful waves W1 for the study of the region of interest M concerned.

[0121] To do this, a second electromagnetic field EM2 is produced by generating auxiliary electrical signals SG2 (or masking signals). This second field opposes the first electromagnetic field EM1 resulting from the first electrical signals SGI used to produce the useful waves W1, which advantageously makes it possible to attenuate, or even cancel, the electromagnetic field EM1 and therefore to minimize the total electromagnetic field EM3 produced by the emitting device 20.

[0122] According to one example, the auxiliary signals SG2 advantageously make it possible to reduce, or even cancel, the magnetic field generated by the system, and thus to significantly reduce the far electromagnetic field with respect to the system SY1.

[0123] The production of this second EM2 field can advantageously be implemented in an existing emitting system or device 20, without requiring additional devices and / or structural modifications of this device. The complexity and cost of implementing the method can thus be limited.

[0124] It is thus advantageously possible for a wave emitting device to comply with a standard in force in terms of maximum authorized EM emission.

[0125] Electromagnetic emissions can be effectively limited in the various operating modes of the emitting device. In the case where the emitting device 20 is an ultrasound device, examples of different operating modes of said device can include a B mode (i.e., a brightness mode), a Doppler mode, or a ShearWave(r) mode (i.e., a shear wave elastography mode). In other words, it is not necessary to change or modify the specific operating mode of the emitting device 20 to achieve the electromagnetic emission reductions according to the concept of the present disclosure. Such electromagnetic emission reductions can thus be achieved independently of the specific operating mode. selected, that is to say whatever the operating mode implemented by the transmitting device.

[0126] A part (for example a first half) of the transducer elements 22 of the transmitter device 20 can for example be used to output useful signals W1 while another part (for example the other half) of the transducer elements 22 is used to produce a second electromagnetic field EM2 which attenuates or cancels the electromagnetic field EM1.

[0127] According to one example, a group of electrical connections 24 are connected to the transmitting device 20. During the control method, an assignment step (not shown) is carried out to assign (or select) electrical connections of this group to serve respectively either as a first electrical connection 24a (transport of the useful signals SGI) or as a second electrical connection 24b (transport of the auxiliary signals SG2).

[0128] This assignment can for example be configured so that an electrical connection 24 serves as a first electrical connection 24a and a second electrical connection 24b at different times.

[0129] The control device 10 can for example configure the electrical connections 24 so that they switch (or alternate) over time between a “useful” mode in which they are used to deliver useful signals SGI, and an “auxiliary” mode in which they are used to deliver auxiliary signals SG2. Thus, an electrical connection 24 can be used sequentially (one after the other) in both modes.

[0130] According to one example, the control device 10 performs a cyclic permutation of the assignment of the electrical connections 24 as first electrical connections 24a (useful mode) or second electrical connections 24b (auxiliary mode). The cyclical nature of the permutation advantageously makes it possible to distribute or spread the electrical noise of the system (smoothing or averaging effect) and the disparities of the intrinsic characteristics of the system (in particular of the electrical connections 24), such as the impedances, couplings, etc. of the system. In the case, for example, of an imaging application, the quality of the images constructed on the basis of the signals transmitted and received in return is thus significantly improved.

[0131] According to one example, the assignment of the electrical connections 24 either as a first electrical connection 24a or as a second electrical connection 24b is carried out according to a (or at least one) random (or pseudo-random) time sequence. It can thus be chosen randomly over time which electrical connections are used in useful mode and which electrical connections are used in auxiliary mode. The use of a random or pseudo-random time sequence advantageously makes it possible to avoid the repetition of sequences of fortuitous signal patterns and to avoid that the signals exhibit unwanted periodicity properties, which ensures better smoothing or averaging of electrical noise and disparities in system characteristics.

[0132] According to a variant, the assignment is carried out according to a predefined time sequence. The time sequence(s) can be predefined and thus optimized during the system development stage, pre-recorded and reproduced on demand during operation.

[0133] According to one example, at least one electrical connection is dedicated to the transport of the auxiliary signals SG2. Thus, the generation of the auxiliary signals SG2 is controlled so that an electrical connection 24 is used as a second electrical connection 24b and not as a first electrical connection 24a. In other words, this electrical connection can be used only as a second electrical connection 24b over time, for example during the same scanning phase during an examination or other.

[0134] According to one example, a single electrical connection 24b is used to transport the auxiliary signals SG2, which advantageously simplifies the design, manufacturing and development. In one example, this single electrical connection 24 is dedicated to transporting the auxiliary signals SG2. The current 12 can then be generated so as to compensate for the sum of the currents II. The use of a single electrical connection 24b conducting an inverse current 12 equal to the sum of the currents II advantageously makes it possible to reduce the electromagnetic noise with limited implementation complexity, for example by using a voltage generator to generate the auxiliary signals SG2.

[0135] As already indicated, the generation of the useful signals SGI and auxiliary signals SG2 causes the circulation of opposite currents II and I2 in the first and second electrical connections 24a and 24b respectively. According to one example, the useful signals SGI and auxiliary signals SG2 are controlled over time so that the algebraic sum of the currents II and I2 is (or remains) less than the current II. This control can be ensured by the control device 10 so that the current I2 is at all times opposite to the current II during an operating phase (for example at each step of a scanning phase). It is thus advantageous to attenuate or limit the total electromagnetic radiation EM3 of the emitting system SY1 during this operating phase.

[0136] In particular, the useful signals SGI and auxiliary signals SG2 can be controlled over time so that the algebraic sum of the currents II and I2 tends towards, or is substantially equal to, zero. By making this algebraic sum tend towards zero, it is advantageous to minimize (or even cancel) the total electromagnetic radiation EM3 to the extent that the fields EM1 and EM2 compensate each other, or even cancel each other out.

[0137] According to one example, the useful signals SGI and auxiliary signals SG2 generated by the control device 10 are wave (or alternating, or periodic) signals.

[0138] According to one example, the sum of the SGI signals and the sum of the SG2 signals have opposite waveforms to obtain an algebraic sum of the currents II and I2 equal, or substantially equal, to zero.

[0139] According to one example, the useful signals SGI and auxiliary signals SG2 are generated simultaneously. It is also advantageous to effectively attenuate the total electromagnetic field EM3 emitted by the system SY1. The auxiliary signals SG2 are generated in the second electrical connection(s) 24b while the useful signals SGI are delivered via the electrical connection(s) 24a to the transmitting device 20 to cause the transmission of the useful waves W1.

[0140] Alternatively, the signals SGI and SG2 are offset over time and do not overlap ([Fig.2]). The useful signals SGI and auxiliary signals SG2 are then generated during respective transmission periods which are separated in time by a delay short enough for the sum of the currents II and I2 to be less than II. Thus, a relatively small time offset is allowed between the signals SGI and SG2 so that the electromagnetic field generated by the system SY1 is at least partially reduced. This offset is sufficiently small to obtain the effect of compensating the first electromagnetic field EM1 by the second electromagnetic field EM2. The smaller this time offset, the more effectively the electromagnetic field EM3 generated by the system SY1 can be reduced, or even cancelled.

[0141] According to one example, the useful waves Wl are emitted at a wavelength X. The first electrical connection(s) 24a are then arranged so as to be spaced from the second electrical connection(s) by a distance D such that D < X / 10. Compliance with this condition advantageously makes it possible to guarantee satisfactory attenuation of the total electromagnetic field EM3. For example, the wavelength X is equal to one (1) meter and D is set at one (1) cm in order to comply with the above condition.

[0142] Furthermore, as already indicated, the transmission of the useful signals SGI through the electrical connection(s) 24a causes the emission by the emitting device 20 of useful waves W1 in the area of ​​interest M. As illustrated in FIGS. 5 and 7 in exemplary embodiments, the useful signals SGI can be controlled to cause the focusing of the useful waves W1 in the area of ​​interest M. The manner in which the auxiliary signals SG2 are processed at the level of the emitting device 20 can, however, vary according to the case as described below in exemplary embodiments.

[0143] According to one example, the generation of the auxiliary signals SG2 in the second electrical connection(s) 24b is configured to cause the emission, by the emitting device 20, of second waves, called auxiliary waves W2. Insofar as these auxiliary waves W2 are not intended to be used to analyze the area of ​​interest M, the auxiliary signals SG2 can optionally be controlled to direct the auxiliary waves W2 out of the area of ​​interest M. To do this, the dummy signals SG2 can for example be voltage signals whose waveform is controlled to focus the auxiliary waves W2 out of the area of ​​interest M.

[0144] As shown by way of example in [Fig.7], the useful waves W1 can thus be focused at a focal point 32 located in the area of ​​interest M while the auxiliary waves W2 are directed outside the area of ​​interest M, for example focused at focal points 34 located outside the area of ​​interest M. This configuration advantageously makes it possible to avoid disturbing the analysis of the area of ​​interest M. In particular, it is advantageous to avoid disturbing waves received from the area of ​​interest M in response to the useful waves W1. In the case of an imaging application, this advantageously makes it possible to avoid degrading an image generated from a response of the area of ​​interest to the useful waves W1.

[0145] According to a variant shown in [Fig.8], the emitting device 20 comprises a blocking means 50. During the control method, the blocking means 50 blocks (or attenuates) at least part of the emission, by the emitting device 20, of auxiliary waves W2 in response to the auxiliary signals SG2. The nature and configuration of this blocking means 50 may vary depending on the case, and may in particular be physical and / or electrical as described below.

[0146] The blocking means 50 may for example comprise a physical blocking element 50a, for example taking the form of a layer of material positioned in or on the emitting device 20 so as to at least partially block the auxiliary waves W2 at the output of the emitting device 20. This physical blocking element 50a comprises for example a material arranged to block or attenuate the ultrasonic waves W2 likely to be emitted at the output of the piezoelectric transducers 22 in response to the auxiliary signals SG2. Thus, the blocking means 50a prevents the emission of the auxiliary waves W2 at the output of the emitting device 20.

[0147] The blocking means 50 may for example comprise an electrical blocking element, taking for example the form of an impedance Z (or impedance load) which is connected to the second electrical connection(s) 24b to obstruct (or oppose), in particular electrically, the auxiliary signals SG2. In the case of an impedance of the capacitance or resistance or shielded inductance type for example, no (or almost no) magnetic field is generated. Such an electrical blocking element Z is inexpensive, not very restrictive to implement and advantageously does not involve any unwanted W2 wave emission. As illustrated in [Fig. 9], this impedance Z may for example be equivalent to an RLC circuit (a set of resistance R, inductance L and capacitance C in series, to which a capacitance Cp is coupled in parallel). According to one example, the impedance Z is a capacitive impedance obstructing the auxiliary signals SG2 in the transmitter device 20. According to one example, the impedance Z is an inductive impedance obstructing the auxiliary signals SG2 in the transmitter device 20. According to one example, the impedance Z is a resistance obstructing the auxiliary signals SG2 in the transmitter device 20.

[0148] The impedance Z is a function of the signal frequency and can therefore have a given value at a given frequency (for example at a frequency f = 50 MHz). In this case, the current 12 is such that:

[0149] [Math. 1] 12 = V2 / Z

[0150] For a capacitance, the impedance Z is such that:

[0151] Z =1 / (2^- / -0

[0152] Where f is the frequency of the auxiliary signals SG2 and C is the capacitance of the impedance Z.

[0153] The electrical blocking element Z may for example be configured to emulate a piezoelectric transducer element 22 without however emitting auxiliary waves W2 at the output. According to one example, this electrical blocking element Z is a non-wave emitting piezoelectric element.

[0154] [Fig. 10] schematically represents an example of implementation of the control device 10. As illustrated, the control device 10 may comprise: - a pulser 16 configured to deliver useful signals SGI to the transmitting device 20 via a first electrical connection during a transmission operation 24a, this pulser 16 being able to be used as a first power source 16a and / or second power source 16b ([Fig.5]); and - a pulser 17 configured to receive electrical signals in reception from the transmitting device 20 during a reception operation.

[0155] An electrical connection 24 may comprise a switch 40 configured to allow switching between a transmission mode in which the control device 10 transmits SGI or SG2 signals through the electrical connection, and a reception mode in which the control device 10 receives electrical signals from the transmitter device 20.

[0156] [Fig. 11] schematically represents an example of implementation of a second power source 16b ([Fig.5]) configured to deliver auxiliary signals SG2 to the transmitter device 20. In this example, the power source 16b is a power supply circuit comprising a voltage generator capable of delivering auxiliary signals SG2 in voltage (+Vdd / -Vdd) to the transmitter device 20 to induce a current I2, in the electrical connections 24b, opposite to the current II of the useful signals SGI. This power supply circuit comprises switches 44 and 46 configured to transmit a time signal dependent on the voltage generator. The switches 44 and 46 close one after the other so that only one of the two switches is closed at a given time. For example, these switches 44 and 46 transmit either the voltage +Vdd when the switch 44 is closed and the switch 46 is open, or the voltage -Vdd when the switch 44 is open and the switch 46 is closed.

[0157] As understood by a person skilled in the art, all the embodiments and variants described above, some of which have been deliberately simplified to facilitate explanations, constitute only non-limiting examples of implementation of the present disclosure. In particular, a person skilled in the art may envisage any adaptation or combination of the embodiments and variants described above, in order to meet a particular need.

[0158] The present disclosure is therefore not limited to the embodiments described above but extends in particular to a treatment method which would include secondary steps without thereby departing from the scope of the present disclosure. The same would apply to a treatment system for implementing such a method.

Claims

Claims

1. Method for controlling a transmitting device (10) for transmitting waves (W), said method comprising: - controlling (S2) the transmitting device by generating first electrical signals (SGI), called useful signals, through at least one first electrical connection (24a), producing first waves (Wl) at the output of the transmitting device and a first electromagnetic field (EM1); and - producing (S4) a second electromagnetic field (EM2) opposite to the first electromagnetic field by generating in at least one second electrical connection (24b) second electrical signals (SG2), called auxiliary signals, of current I2 opposite to the current II of the useful signals.

2. The method of claim 1, wherein the useful signals (SGI) are generated by a first power source (16a) and the auxiliary signals (SG2) are generated by a second power source (16b).

3. The method of claim 2, wherein the first and second electrical power sources (16a, 16b) are separate sources or common sources.

4. A method according to any preceding claim, wherein a group of electrical connections (24) are connected to the transmitting device, the method comprising: - assigning the electrical connections of the group, to serve respectively either as a first electrical connection (24a) or as a second electrical connection (24b).

5. The method of claim 4, wherein the assignment is performed according to a random time sequence.

6. The method of claim 4, wherein the assignment is performed according to a predefined time sequence.

7. A method according to any one of claims 4 to 6, wherein said allocation is configured so that one electrical connection (24) serves as a first and second electrical connection (24a, 24b) at different times.

8. A method according to any preceding claim, wherein the generation of the auxiliary signals (SG2) is controlled so that one electrical connection is used as a second connection. electrical (24b) and not as the first electrical connection (24a).

9. Method according to any one of the preceding claims, said at least one second electrical connection (24b) in which the auxiliary signals (SG2) are generated being one or more electrical connections other than said first electrical connection (24a).

10. Method according to any one of the preceding claims, in which the generation of the useful and auxiliary signals (SGI, SG2) causes the circulation of opposite currents II and I2 in respectively said at least one first and second electrical connections (24a, 24b), said useful and auxiliary signals being controlled over time so that the algebraic sum of the currents II and I2 is less than the current II.

11. Method according to claim 10, in which the useful and auxiliary signals (SGI, SG2) are controlled over time so that the algebraic sum of the currents II and I2 tends towards, or is substantially equal to, zero.

12. Method according to any one of the preceding claims, in which the useful and auxiliary signals (SGI, SG2) are generated simultaneously.

13. A method according to any preceding claim, wherein the useful and auxiliary signals (SGI, SG2) are generated during respective transmission periods which are separated in time by a delay sufficiently short for the sum of currents II and I2 to be less than II.

14. Method according to any one of the preceding claims, in which the first waves (Wl) are emitted at a wavelength X, said at least one first electrical connection (24a) being spaced from said at least one second electrical connection (24b) by a distance D such that D < X / 10.

15. Method according to any one of the preceding claims, in which the transmitting device (20) comprises blocking means (59), the method comprising: - blocking, by the blocking means, at least part of the transmission, by the transmitting device, of second waves (W2), called auxiliary waves, in response to the auxiliary signals.

16. A method according to claim 15, wherein the blocking means comprises an impedance load (Z), connected to said at least one second electrical connection (24b), obstructing the signals

17.

18.

19.

20. auxiliaries (SG2). Method according to any one of the preceding claims, in which said first waves (Wl) produced at the output of the transmitting device are acoustic waves. Method according to any one of the preceding claims, wherein said method is applied to medical ultrasound imaging. Computer program (PG1) comprising instructions for carrying out the steps of a method according to any one of the preceding claims when said program is executed by a computer. Control device (10) for controlling a wave emitting device (20), said control device comprising: - control module (MD2) configured to control the transmitting device by generating first electrical signals (SGI), called useful signals, through at least a first electrical connection (24a), producing first waves (W1) at the output of the transmitting device and a first electromagnetic field (EM1); and - production module (MD4) configured to produce a second electromagnetic field (EM2) opposite to the first electromagnetic field by generation in at least one second electrical connection (24b) of second electrical signals (SG2), called auxiliary signals, of current opposite to the current of the useful signals.

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