DEVICE FOR SUPPLYING POWER TO AN ULTRASONIC TRANSDUCER AND SYNCHRONIZATION METHOD - Patent application

Abstract

The present invention relates to a method and circuit (100) for driving and supplying power to an ultrasonic transducer having a synchronous switching capacitance controlled by a digital loop. The circuit (100) comprises a power interface (106) controlled by a multilevel square or rectangular signal generator (102). The device comprises a tuning circuit (104) controlled by a tuning control circuit (109) and having a natural frequency determined using the transducer. Typically, the tuning comprises an inductor (L1) in series at the input and a capacitor (C1) in control connection (K1) attached at the output in parallel with the transducer (302). This connection (K1) controls the detected phase (Δφ) detected between the input (φ1) and output (φ2) of the inductor (L1). 12 ) difference. This connection is advantageously controlled to provide a phase difference equal to π / 2. The invention further relates to an ultrasound element, an ultrasound head, and an ultrasound imaging and / or processing system, particularly in medical applications. Summary: See Figure 2

Description

[Technical field]

[0001] The present invention relates to a method and a circuit for driving and supplying an ultrasonic transducer having a synchronous switched capacity controlled by a digital loop. The circuit comprises a power interface controlled by a multi-level square or rectangular signal generator. The device comprises a tuning circuit controlled to have a natural frequency determined by means of the transducer.

[0002] Typically, this tuned circuit comprises at its input a series inductor and at its output a controlled connected capacitor mounted in parallel with the transducer, this connection being controlled according to the phase difference detected between the input and the output of said inductor, this connection being advantageously controlled to provide a phase difference equal to π / 2.

[0003] The invention further relates to ultrasound elements, ultrasound heads and ultrasound imaging and / or processing systems, particularly in medical applications. [Background technology]

[0004] Ultrasonic transducers are widely used, especially in the medical field, as emitters and receivers for imaging by echography or even ultrasound treatment. To do this, several transducers are typically arranged in a matrix, also called an "ultrasonic head", to emit focused and high-power ultrasound waves at the area to be imaged or treated. Each ultrasonic transducer is supplied with a sinusoidal signal at a given frequency so as to generate an ultrasonic signal of said frequency.

[0005] Typically, the ultrasound head comprises an individual control chain for each ultrasound transducer, which makes it possible to modify individually, for each transducer, the amplitude of the ultrasound signal emitted by said transducer, as well as its frequency and phase. Thus, the characteristics of the ultrasound transmitted by each transducer of the matrix can be modified.

[0006] However, known control chains for ultrasonic transducers have poor efficiency. Furthermore, the sinusoidal control signals provided by known control chains are of poor quality and degrade the ultrasonic signal. Finally, known control chains are generally bulky and energy consuming.

[0007] One object of the present invention is to overcome all or some of the disadvantages of the prior art, in particular at least one of the disadvantages mentioned above.

[0008] Another object of the invention is to propose a device for supplying electrical power to an ultrasonic transducer that is more efficient in terms of efficiency.

[0009] Another object of the invention is to propose a device for supplying power to an ultrasonic transducer, which provides a sinusoidal supply signal of higher quality.

[0010] Another object of the invention is to propose a device for supplying electrical power to ultrasonic transducers that is less bulky, more energy-efficient and / or easier to manufacture in large quantities.

[0011] Another object of the invention is to propose a device for supplying power to ultrasonic transducers, which makes it possible to modify the power of the ultrasonic signal by modifying the amplitude of the signal supplied to each transducer.

[0012] Another object of the invention is to propose a device for supplying power to ultrasonic transducers, which allows the modification of the focal plane by modifying the frequency or the phase of the signal supplied to each transducer.

[0013] Another object of the present invention is to allow signals to be fed to more ultrasonic transducers in an ultrasonic head. Summary of the Invention

[0014] For this purpose, the present invention proposes a device for supplying power to an ultrasonic transducer, comprising a power interface configured to receive a drive signal, in particular a multi-level square or rectangular signal, provided by a multi-level square or rectangular signal generator controlled by a digital interface and to provide an analog power signal to said ultrasonic transducer so as to generate ultrasonic waves at a set point frequency.

[0015] Typically, the power interface performs amplification of the multi-level square or rectangular signal generated by a digital square or rectangular multi-level signal generator, which amplification is performed in particular by a class "D" amplifier. Typically, the supply device comprises a digital interface that controls the multi-level square or rectangular signal generator, whereby the multi-level square or rectangular signal generator generates a multi-level square or rectangular signal having a frequency, phase and amplitude respectively representative of the frequency, phase and amplitude of the transmitted ultrasound.

[0016] According to the invention, the supply device further comprises a tuning circuit mounted between the interface and the ultrasonic transducer, which tuning circuit is controlled (preferably digitally) by a tuning control circuit, whereby the assembly formed by the transducer and said tuning circuit has a determined resonant frequency that is in particular tuned to said set point frequency.

[0017] Typically, a connectable or adjustable capacitor is placed in the tuning circuit, e.g., in parallel with the transducer. Carried out by This impedance modification.Typically, the tuned circuit also filters harmonics of the analog power signal that supplies power to the transducer, for example by means of an inductor mounted in series with the analog power signal through which it passes.

[0018] Preferably, the tuned circuit comprises an inductor mounted in series with its input and a control-connected capacitor mounted in parallel with the transducer at its output.

[0019] This connection is controlled as a function of a detected phase difference between an input phase and an output phase detected at the input and output sides of the inductor.

[0020] More specifically, the tuning circuit comprises a feedback circuit arranged to control the connection of the capacitors so as to ensure that the detected phase difference reaches a determined set point value.

[0021] In a preferred embodiment, the feedback circuit comprises: a synchronous extraction circuit for detecting an output phase; a phase comparator circuit for receiving or detecting an input phase, particularly before the input of the power interface and, for example, after a multi-level square or rectangular signal generator, and for comparing the input phase with the output phase to derive a detected phase difference therefrom; a summing circuit for comparing the detected phase difference with the set point value to control a correction circuit; Equipped with The correction circuit controls the output synchronization circuit, which in turn controls the opening and closing of capacitor connections in a controlled manner in real time to set and / or maintain the detected phase difference at a set point value.

[0022] Typically, this feedback circuit is fully digital or mostly digital, except for the sync extractor, which is a mixed circuit.

[0023] According to an advantageous particular feature, the connections of the capacitors are controlled so that the detected phase difference reaches a tuning value equal to π / 2.

[0024] According to another particular feature, the connections of the capacitors are controlled by a synchronization signal operating with pulse width modulation (PWM).

[0025] Preferably, the supply device determines the following parameters to generate the drive signal: The frequency of the drive signal; the amplitude of the drive signal; Phase of the drive signal providing at least one of any combination of determining said parameters from instruction data received by a supplying device, said parameters comprising: the frequency of the acoustic signal emitted by the transducer, the amplitude of the acoustic signal emitted by the transducer, The phase of the acoustic signal emitted by the transducer respectively, It further includes a digital control interface.

[0026] Potentially, several power supply devices are controlled by the same digital interface.

[0027] Advantageously, the tuning control circuit as well as the control and generation circuit of the analog power signal at the input of the inductor, referred to as the primary supply signal, are made completely or partly by digital circuits.

[0028] Preferably, the supply device is partly or wholly integrated in at least one integrated circuit, in particular alone or in association with other electronic components.

[0029] According to another aspect, the present invention provides a method for producing ... liquid crystal display comprising: An ultrasonic transducer; a supply device as disclosed herein arranged to supply a signal to said at least one ultrasonic transducer; An ultrasonic device comprising:

[0030] According to a particular feature, such an ultrasound device may comprise a single transducer and a single supply device, itself equipped with its own digital interface.

[0031] According to another particular feature, several delivery devices are controlled by the same digital interface, and the invention proposes a so-called composite ultrasound device comprising several ultrasound devices sharing a common digital interface.

[0032] According to yet another aspect, the invention proposes an ultrasound head comprising several ultrasound devices as described herein, arranged and / or controlled in parallel.

[0033] In the ultrasound head according to the invention, each ultrasound transducer is associated with a dedicated supply device so that each ultrasound transducer can be individually controlled, and therefore the characteristics of the ultrasound generated by each ultrasound transducer of the ultrasound head according to the invention can be individually modified.

[0034] In particular, the amplitude, frequency and phase of the ultrasound emitted by each ultrasound transducer of the ultrasound head can be varied individually for each ultrasound transducer.

[0035] The ultrasound head according to the invention can be used for medical imaging, in particular for ultrasound imaging.

[0036] Alternatively or additionally, the ultrasound head according to the invention may be used in medical treatments.

[0037] Alternatively or additionally, the ultrasound head according to the present invention may be used for aesthetic procedures.

[0038] Alternatively or additionally, an ultrasound head according to the invention may be used to image a workpiece, for example for quality control purposes, or even to process the workpiece.

[0039] According to another aspect, the present invention provides a method for producing a method for manufacturing a pharmaceutical composition comprising: An ultrasonic head as disclosed herein; At least one digital controller for the ultrasonic device of the ultrasonic head; An ultrasound system is proposed, comprising:

[0040] According to one embodiment, the ultrasound system according to the invention may comprise for at least one, in particular each, ultrasound device of the ultrasound head, an individual digital control device dedicated to said ultrasound device.

[0041] In this case, each ultrasound device of the ultrasound head receives data regarding the ultrasound waves it generates from a dedicated digital controller.

[0042] The system according to the invention may be an ultrasound imaging system, in which case the system may comprise means for processing ultrasound waves to generate at least one ultrasound image, in a known manner.

[0043] The system according to the invention may also be a treatment system, in which case it comprises means for processing the emitted ultrasound waves in a known manner to carry out a treatment.

[0044] According to certain preferred features, the system is arranged to provide a medical imaging system and / or a medical treatment system, for example for dissolving kidney stones.

[0045] According to another aspect of the invention, the use of the system according to the invention is proposed for medical imaging.

[0046] According to another aspect of the invention, the use of the system according to the invention is proposed for the aesthetic treatment of at least one zone of the human or animal body.

[0047] According to yet another aspect, the present invention relates to a method for supplying an ultrasonic transducer with a so-called secondary supply signal to generate ultrasonic waves at a setpoint frequency, the method comprising: - generating an analog power signal, a so-called primary supply signal, in the power interface, which is used to supply the ultrasonic transducer through a tuning circuit with an adjustable impedance, in particular including a connectable or adjustable capacitance; controlling said tuning circuit to change its impedance, so that the assembly formed by the transducer and said tuning circuit has a determined resonant frequency that is specifically tuned to said set point frequency; The present invention proposes a method comprising the steps of:

[0048] Typically, the method is implemented within a power delivery device, or an ultrasound device, or an ultrasound head, or an ultrasound system as described herein.

[0049] According to one feature, the change in tuning of the tuned circuit is carried out by synchronous switching of a capacitor mounted in parallel with the transducer.

[0050] According to another particular feature, the switching of the capacitor teeth, The control is performed by a feedback control related to a detected phase difference between an input phase and an output phase, which is detected at the input and output sides of an inductor mounted in series between the power interface and the transducer.

[0051] The invention helps to solve the problem of driving a matrix of transducers, especially in devices that must be MRI compatible for ultrasound medical procedures.

[0052] The present invention realizes a device that does not interfere with the magnetic field of the MRI and allows the amplitude, frequency and phase of the drive signal of each transducer to be individually controlled. This individual control makes it possible to change the focal point. This ability to change the focal point makes it possible to follow the moving member and treat larger areas, thus facilitating the physician's work. With its synchronous switching system based on synchronous switching capacitance, the present invention provides high energy conversion efficiency and at the same time makes it possible to reduce the dimensions of the head and the entire system, thereby allowing to increase the number of ultrasonic transmission elements in the transducer array with all the resulting advantages.

[0053] Thus, the present invention makes it possible to control each transducer independently in an MRI device, controlling its amplitude, frequency and phase. Compared to existing solutions, this can allow a finer control of the settings of each transducer. This allows the physician to provide more precise processing manipulation and possibly new uses of this type of treatment. Several objectives are possible, such as monitoring of moving members controlled by MRI or treatment of larger areas to treat tumors of larger size.

[0054] The present invention allows the use of an architecture based primarily on digital circuits, making the system more robust and easier to develop and implement, which may allow for reduced manufacturing costs compared to analog solutions that are complex and difficult to tune.

[0055] This allows, among other things, the following options: -Digital-first architecture that is easier to implement, reduces costs, has the prospect of higher integration, and improves robustness -Individual control of amplitude, frequency and phase of the control signal for each transducer - Automatic adjustment of the transducer, i.e. "auto-tuning", which makes it possible to set the amplitude, frequency and phase, allowing the doctor to adjust the focus and also ensuring optimal efficiency of energy conversion at any time. -Increasing the deflection of the ultrasound signal by adjusting the depth and focus through changes in frequency and / or phase. -Improved focusing accuracy.

[0056] It will be appreciated that a method according to the present invention may include any combination of at least one of the features described above with respect to the method, which will not be repeated here for the sake of brevity.

[0057] Various embodiments of the invention are provided that incorporate different optional features described herein in all of their possible combinations. [Brief description of the drawings]

[0058] Other features and advantages will become apparent from the detailed description of entirely non-limiting embodiments and from the accompanying drawings, in which: [Figure 1] FIG. 2 is a schematic diagram of a non-limiting embodiment of a power supply device for an ultrasonic transducer. [Diagram 2] FIG. 2 illustrates a more detailed embodiment of the power supply device of FIG. [Diagram 3] 2 is a schematic diagram of a non-limiting embodiment of an ultrasound device according to the present invention including the delivery device of FIG. 1. [Figure 4] FIG. 4 is a schematic diagram of a non-limiting embodiment of an ultrasound head according to the present invention, including an exemplary matrix of “n” devices of FIG. [Diagram 5] FIG. 5 is a schematic diagram of a non-limiting embodiment of an ultrasound system according to the present invention including the head of FIG. [Figure 6] FIG. 5 is a schematic diagram of a non-limiting embodiment of an ultrasound system according to the present invention including a variation of the head of FIG. 4 having a composite subassembly.

[0059] The embodiments described below are in no way limiting. In particular, it is possible to imagine variants of the invention that include only a selection of features disclosed below, apart from the other features disclosed, if this selection of features is sufficient to provide a technical advantage or to distinguish the invention with respect to the prior art. This selection includes at least one, preferably functional, feature without structural details or with only a part of structural details, if that part alone is sufficient to provide a technical advantage or to distinguish the invention with respect to the prior art.

[0060] In the figures, the same reference numbers are used for elements that are common to several figures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] The invention proposes a structure that makes it possible to control an ultrasonic transducer, especially in the context of a medical procedure.

[0062] Transducer 302 i is typically arranged as a matrix of n transducers, where "i" ranges from 1 to n.

[0063] Their combination allows to emit high power ultrasound waves, which can be focused by emitting different transducers simultaneously, but at different phases with each other. In such an architecture, each transducer 302 has its own control interface, thus forming an ultrasonic device 300 (also called an ultrasonic device). These ultrasonic devices form individual ultrasonic elements in an assembly 400 that forms an ultrasonic (or ultrasonic) head.

[0064] In an operational ultrasound system 500, all ultrasound elements 300 are controlled by a digital system 502, typically a computer associated with a dialogue interface, allowing the physician to set the ultrasound power and focus. These settings are translated by the digital system into individual controls for each element of the ultrasound head in amplitude, frequency, and phase. Via a communication bus 504, each of these individual controls is sent to the digital interface 108 of the corresponding ultrasound element 300 in the ultrasound head 500.

[0065] For each ultrasonic element 300, this structure receives an analog power signal “s a " simultaneously controls and supplies the ultrasonic transducer 302. This primary signal s a is generated by the power interface 106, which receives the driving signal “s” coming from the generator 102 of a square or rectangular multi-level rectangular signal. p " is controlled by a digital signal forming

[0066] Each of the digital multi-level square or rectangular signal generators 102 is controlled by a corresponding digital interface 108 in frequency “F1”, phase “φ1” or even amplitude “A1”.

[0067] The power interface 106 is typically an "H" half-bridge and / or a "D" class amplifier. Typically, the power interface 106 therefore emits a primary multi-level square or rectangular supply signal of the same frequency F1 and the same phase φ1.

[0068] The ultrasonic transducer 302 is in series with an inductor L1, which allows filtering of harmonics of the multi-level square or rectangular signal, resulting in a sinusoidal signal "s'" that may qualify as a "secondary" feed signal. a" to the terminals of the transducer 302. A capacitor C1 is placed in parallel with the transducer 302 using an electronic switch K1. The primary signal s leaving the power interface 106 is typically a By switching in the capacitor C1 during a determined portion of each period, a change in the impedance of the tuned circuit 104 is made, making it possible to displace the resonant point (i.e., its resonant frequency F30) of the assembly 301 formed by the inductor L1, the capacitor C1, and the transducer 302, i.e., the assembly which can be described as a “tuned transducer” 301.

[0069] It should be noted that the multi-level square or rectangular signal generator 102, the phase comparator 112, the set point 110 and its summer 113, the corrector 114 and the output synchronization stage 115 are preferably provided entirely by digital circuits.

[0070] 3 is a schematic diagram of a non-limiting exemplary embodiment of an ultrasonic device according to the invention. The ultrasonic device 300 shown in FIG. 3 comprises an ultrasonic transducer 302 powered by a supply device according to the invention, in particular the supply device 100 of FIG.

[0071] 4 is a schematic diagram of a non-limiting exemplary embodiment of an ultrasonic device according to the present invention. The ultrasonic head 400 of FIG. 4 includes “n” ultrasonic devices 3001-3000 arranged in parallel to form a matrix. n Equipped with.

[0072] Ultrasonic Devices 3001-300 n At least two of may be the same or different from each other.

[0073] Each ultrasonic device 300 i may be identical to the ultrasonic device 300 of FIG. 3, with all elements of device 300 having the same reference numbers ending with the subscript "i".

[0074] FIG. 5 is a schematic diagram of a non-limiting exemplary embodiment of an ultrasound system in accordance with the present invention.

[0075] The ultrasound system 500 of FIG. 5 includes an ultrasound head according to the present invention, such as ultrasound head 400 of FIG.

[0076] The ultrasound system 500 includes an ultrasound head 400 and an ultrasound device 300. i , in particular the control interface 108 of the ultrasound device i The system further comprises a control device 502, such as a computer or tablet, or more generally any computing device, connected to the

[0077] In the illustrated example, the controller 502 communicates with each of the control interfaces 108 via digital communication 504 and wired communication 504. i Alternatively, for example, each control interface 108 i , or only a portion of them, may be in communication with the controller 502 via a wireless link.

[0078] The control device 502 controls each ultrasonic device 300 i to vary the frequency, phase, and / or amplitude of the ultrasound emitted by the other ultrasonic device 300. i Each ultrasonic device 300 is independent of the other. i This allows each ultrasonic device 300 to be controlled. i This allows simple, dynamic and responsive adjustment of the amplitude, frequency and phase of each ultrasonic wave transmitted by the different elements 300. i Regarding the phases, which are different from each other but adjusted to each other, and the ultrasonic devices 3001 to 300 n By controlling the amplitude of the ultrasound emitted by the ultrasonic beam, it is possible to adjust the focal point simply, flexibly and responsively.

[0079] For example, when the invention is implemented in a medical imaging device or even in therapy, it is thus possible to quickly and accurately change the wave focus of the head 400, for example to perform real-time monitoring of moving parts.

[0080] FIG. 6 illustrates a system 600 including a plurality of “n” ultrasonic composite devices 3061-3066. n 5, with a head 406 made up of: 11 In each of the examples shown, the same common interface 1081 is used to provide power to a single transducer 302. 11 ~302 1m A plurality of “m” supply devices 100 supplying 11 ~100 1m Similarly, block 306n controls A single digital interface 108n directly controls the supply devices 100n1~100nm of the transducers 302n1~302nm respectively Equipped with.

[0081] This allows digital interface blocks 1081-108, each capable of directly controlling a group of "m" transducers in the matrix. m It will be possible to bring about.

[0082] The matrix then consists of nm transducers associated with "n" groups of "m" transducers. This number "m" is not necessarily constant and can be variable within a head from one subset to another. Typically, this grouping of transducers is small, for example 2 to 16.

[0083] Thus, for example, it is possible to increase the compactness and number of components in the digital interface within the head. It is also possible to industrially manufacture a compact standard subassembly containing the digital interface and "m" transducers, and that standard subassembly 306 may be used in different configurations to manufacture different types of heads.

[0084] Naturally, the invention is not limited to the examples described here, and many adjustments can be made to these examples without going beyond the scope of the invention.

Claims

1. An ultrasonic head (400) comprising several ultrasonic devices (300 1 to 300 n ), each of said ultrasonic devices (300 1 -300 n ) comprises an ultrasonic transducer (302 1 -302 n ) and a supply device (100 1 -100 n ) for individually supplying the ultrasonic transducer (302 1 -300 n ) of said ultrasonic device; For each of said ultrasonic devices (300 1 to 300 n ), said supply devices (100 1 to 100 n ) receive a drive signal (s 102 1 to 102 n ) provided by a multi-level square or rectangular signal generator ( 102 1 to 102 n ) controlled by a digital interface ( 108 1 to 108 n ). ｐ ), in particular a multi-level square or rectangular signal, and an analog power signal (s) to generate ultrasound (US) at a set point frequency (F3). ａ , s' ａ ) to the ultrasonic transducers (302 1 - 302 n), For each of the ultrasonic devices (300 1 -300 n ), the supply device (100 1 -100 n ) further comprises a tuning circuit (104 1 -104 n ) mounted between the power interface (106 1 -106 n ) and the ultrasonic transducer (302 1 -302 n ) of this ultrasonic device, the tuning circuit (104 1 -104 n ) being controlled by a tuning control circuit (109 1 -109 n ) so that the assembly (301) formed by the transducer and the tuning circuit (104 1 -104 n ) has a determined resonant frequency (F3 ) tuned in particular to the set point frequency (F3 ). ０ ) The ultrasonic head (400).

2. For each of the ultrasonic devices (300 1 to 300 n ), the tuning circuit (104 1 to 104 n ) comprises an inductor (L1) mounted in series at its input side and a capacitor (C1) of a control connection (K1) mounted in parallel with the transducers (302 1 to 302 n ) at its output side, the connection (K1) being connected to an input phase (φ １ ) and output phase (φ ２ ) is detected between the phase difference (Δφ １２ 2. The ultrasonic head (400) of claim 1, wherein the ultrasonic head (400) is controlled as a function of

3. For each of the ultrasonic devices (300 1 to 300 n ), the tuning circuit (104 1 to 104 n ) detects the phase difference (Δφ １２ ) is the determined set point value (Δφ ｃ 3. The ultrasonic head (400) according to claim 2, characterized in that it comprises a feedback circuit arranged to control the connection (K1) of the capacitor (C1) so as to ensure that the input power reaches the input power of the ultrasonic head (400).

4. For each of the ultrasonic devices (300 1 to 300 n ), the connection (K1) of the capacitor (C1) is １２ 4. The ultrasonic head (400) of claim 3, characterized in that the tuning value of the first frequency component is controlled to reach a tuning value equal to π / 2.

5. An ultrasonic head (400) as described in any one of claims 2 to 4, characterized in that for each of the ultrasonic devices (300 1 to 300 n ), the connection (K1) of the capacitor (C1) is controlled (115) by a synchronization signal (M2) operating with pulse width modulation.

6. The drive signal (s ｐ ) with the following parameters: The frequency (F) of the drive signal, The amplitude (A) of the drive signal, The phase (φ) of the drive signal providing at least one of any combination of determining said parameters from instruction data received by said device (100) (504), said parameters comprising: the frequency (F3) of the acoustic signal (US) emitted by the transducer, the amplitude (A3) of the acoustic signal (US) emitted by the transducer, The phase (φ3) of the acoustic signal (US) emitted by the transducer respectively, An ultrasound head (400) according to any one of the preceding claims, further comprising, for each of said ultrasound devices (300 1 - 300 n ), a digital control interface ( 108 1 - 108 n ).

7. For each of the ultrasonic devices (300 1 to 300 n ), the tuning control circuit (109 1 to 109 n ) and the analog power signal (s ) at the input of the inductor (L1) are ａ 7. The ultrasonic head (400) according to claim 1, characterized in that the control and generation circuits (108 1 to 108 n , 102 1 to 102 n , 106 1 to 106 n ), the so-called primary supply signal control and generation circuits (108 1 to 108 n , 102 1 to 102 n , 106 1 to 106 n ), are implemented wholly or partly by digital circuits.

8. An ultrasonic head (400) as described in any one of claims 1 to 7, characterized in that for each of the ultrasonic devices (300 1 to 300 n ), it is integrated, partially or in whole, in at least one integrated circuit, in particular alone or in association with other electronic components.

9. The ultrasonic head (400) of any one of claims 1 to 8, wherein the ultrasonic devices (300 1 to 300 n ) are arranged and / or controlled in parallel.

10. An ultrasonic head (400) according to any one of claims 1 to 9, The ultrasonic device (300) of the ultrasonic head (400) １ ~300 ｎ At least one digital controller (502) for An ultrasound system (500).

11. A system (500) according to claim 10, characterized in that it is arranged to provide a medical imaging and / or therapy system.

12. To generate ultrasonic waves at the set point frequency (F3), a so-called secondary power supply signal (s' ａ 10. A method for supplying electrical power to an ultrasonic transducer (302) of an ultrasonic device (300 1 to 300 n ) of an ultrasonic head (400) according to any one of claims 1 to 9, comprising: Power (s') is supplied to the ultrasonic transducer (302) through a tuning circuit (104) having an adjustable impedance. ａ ) the analog power signal used to supply the ａ ) at a power interface (106); Controlling the tuning circuit (104) to change the impedance thereof, so that the assembly (301) formed by the transducer and the tuning circuit (104) has a determined resonant frequency (F3) that is specifically tuned to the set point frequency (F3). ０ ) controlling the tuning circuit (109) to have a A method comprising:

13. 13. The method according to claim 12, characterized in that the impedance modification of the tuned circuit (109) is performed by synchronous switching (K1) of a capacitor (C1) mounted in parallel with the transducer.

14. The switching (K1) of the capacitor (C1) is detected at the input and output sides, respectively, of an inductor (L1) mounted in series between the power interface (106) and the transducer (302). １ ) and output phase (φ ２ ) detected phase difference (Δφ １２ 14. The method according to claim 12, wherein the control is performed by feedback control on the 15. The method according to any one of claims 12 to 14, comprising: The method comprises individual control of the amplitude, frequency and / or phase of drive signals (sp) of supply devices (100 1 to 100 n ) configured to supply to each of the ultrasonic transducers (302 1 to 302 n ) for controlling the ultrasonic transducers (302 1 to 302 n ) of the ultrasonic head (400) to modify the amplitude, frequency and / or phase of the ultrasonic waves generated by each of the ultrasonic transducers (302 1 to 302 n ), in particular to modify their focal points.

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