Device and synchronous method for supplying power to an ultrasound transducer

Abstract

A method and circuit for driving and supplying power to ultrasonic transducers with synchronous switched capacity, controlled by digital loop. This circuit includes a power interface controlled by a multi-level square or rectangular signal generator. This device includes a tuning circuit which is controlled by a tuning control circuit to have, with the transducer, a determined natural frequency. Typically, this tuning includes at the input an inductor in series, and at the output a controlled connection capacitor mounted in parallel with the transducer. This connection is controlled according to a detected phase difference detected between the input and the output of the inductor. It is advantageously controlled to provide a phase difference equal to /2. Also, an ultrasonic element, an ultrasonic head, and an ultrasonic imaging and/or processing system, especially medical.

Claims

1. An ultrasonic head comprising several ultrasonic devices, characterized in that each of said ultrasonic devices comprises an ultrasonic transducer and a supplying device to individually supply power to the ultrasonic transducer of said ultrasonic device, for each of said ultrasonic devices, the supplying device comprises a power interface configured to receive a drive signal, and to provide an analog power signal to said ultrasonic transducer so as to produce an ultrasonic wave of a setpoint frequency, for each of said ultrasonic devices, the supplying device comprises a tuning circuit that is mounted between the power interface and the ultrasonic transducer of said ultrasonic device, which tuning circuit is controlled by a tuning control circuit, wherein the assembly formed by the transducer and said tuning circuit has a determined resonant frequency.

2. The ultrasonic head according to claim 1, wherein, for each of said ultrasonic devices, the tuning circuit comprises an inductor mounted in series on the side of its input, and comprises on the side of its output a controlled connection capacitor mounted in parallel with the transducer, which connection is controlled as a function of a detected phase difference detected between an input phase and an output phase, which are detected on the input side and respectively on the side of the output of said inductor.

3. The ultrasonic head according to claim 2, wherein, for each of said ultrasonic devices, the tuning circuit comprises a feedback circuit which is arranged to control the connection of the capacitor so as to ensure that the detected phase difference arrives at a determined setpoint value.

4. The ultrasonic head according to claim 3, wherein, for each of said ultrasonic devices, control of the connection of the capacitor is configured to cause the detected phase difference to arrive at a tuning value that is equal to /2.

5. The ultrasonic head according to claim 2, wherein, for each of said ultrasonic devices, the connection of the capacitor is controlled by a synchronization signal operating in pulse width modulation.

6. The ultrasonic head according to claim 1, further comprising, for each of said ultrasonic devices, a digital control interface providing, for generating the drive signal, any combination of at least one of the following parameters: a frequency of said drive signal, an amplitude of said drive signal, a phase of said drive signal; and determining said parameters from instruction data that it receives and which respectively represent: a frequency of a sound signal to be emitted by the transducer, an amplitude of a sound signal to be emitted by the transducer, a phase of a sound signal to be emitted by the transducer.

7. The ultrasonic head according to claim 1, wherein, for each of said ultrasonic devices, the tuning control circuit, and the control and generation circuits of the analog power signal at the input of the inductor, so-called primary supply signal, are carried out wholly or partly by digital circuits.

8. The ultrasonic head according to claim 1, wherein, for each of said ultrasonic devices, the device is integrated, partly or entirely, into at least one integrated circuit.

9. The ultrasonic head according to claim 8, wherein integration of the device into the at least one integrated circuit is one of: alone, or with an association between the device and other electronic components of the integrated circuit.

10. The ultrasonic head according to claim 1, wherein said ultrasonic devices are arranged and/or controlled in parallel.

11. The ultrasonic head according to claim 1, wherein the drive signal is one of a multi-level square or rectangular signal provided by a multi-level square or rectangular signal generator controlled by a digital interface.

12. The ultrasonic head according to claim 1, wherein the determined resonant frequency is tuned to the setpoint frequency.

13. An ultrasonic system comprising: the ultrasonic head according to claim 1, and at least one digital control apparatus for the ultrasonic devices of said ultrasonic head.

14. The system according to claim 13, wherein the system is arranged to produce a medical imaging and/or therapy system.

15. A method for supplying power to an ultrasonic transducer of an ultrasonic device of an ultrasonic head according to claim 1, with a secondary power supply signal, to produce an ultrasonic wave of a setpoint frequency, said method comprising the following steps: generating with a power interface an analog power signal primary power supply signal used to power an ultrasonic transducer through a tuning circuit with adjustable impedance; and controlling a tuning circuit so that it controls said tuning circuit so as to modify the impedance thereof, so that the assembly formed by the transducer and said tuning circuit has a determined resonant frequency.

16. The method according to claim 15, wherein the impedance modification of the tuning circuit is carried out by synchronous switching of a capacitor mounted in parallel with the transducer.

17. The method according to claim 15, wherein the switching of the capacitor and controlled by a feedback control relating to a detected phase difference between an input phase and an output phase, which are detected on the side of the input and respectively on the side of the output of an inductor mounted in series between the power interface and the transducer.

18. The method according to claim 15, the method further comprising controlling the ultrasonic transducers of the ultrasonic head by individually controlling one or more of amplitude, frequency, and phase of the drive signal of the supplying device that is configured to supply each of said ultrasonic transducers, to modify one or more of amplitude, frequency, and phase of the ultrasonic wave produced by each of said ultrasonic transducers.

19. The method according to claim 18, wherein modification of the one or more of amplitude, frequency, and phase of the ultrasonic wave produced by each of said ultrasonic transducers comprises modification of a focal point of said ultrasonic wave.

20. The method according to claim 15, wherein the determined resonant frequency is tuned to the setpoint frequency.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages shall become evident from the detailed description of an entirely non-limiting embodiment, and from the enclosed drawings in which:

(2) FIG. 1 is a schematic representation of a non-limiting embodiment of a power supply device of an ultrasonic transducer;

(3) FIG. 2 is a more detailed embodiment of the power supply device of FIG. 1;

(4) FIG. 3 is a schematic representation of a non-limiting embodiment of an ultrasonic device according to the invention, including the supply device of FIG. 1;

(5) FIG. 4 is a schematic representation of a non-limiting embodiment of an ultrasonic head according to the invention, including an exemplary n matrix of the device of FIG. 3; and

(6) FIG. 5 is a schematic representation of a non-limiting embodiment of an ultrasound system according to the invention, including the head of FIG. 4;

(7) FIG. 6 is a schematic representation of a non-limiting embodiment of an ultrasound system according to the invention, including a variant of the head of FIG. 4 with composite subassemblies.

(8) The embodiments that will be described hereafter are by no means limiting. It is especially possible to imagine variants of the invention that comprise only a selection of the features disclosed hereinafter in isolation from the other features disclosed, if this selection of features is sufficient to confer a technical benefit or to differentiate the invention with respect to the prior state of the art. This selection comprises at least one preferably functional feature that lacks structural details, or only has a portion of the structural details if that portion is sufficient on its own to confer a technical benefit or to differentiate the invention with respect to the prior state of the art.

(9) In the figures the same reference has been used for the elements that are common to several figures.

DETAILED DESCRIPTION

(10) The invention proposes a structure that makes it possible to control ultrasonic transducers, especially in the context of medical treatments.

(11) The transducers 302.sub.i are typically arranged as a matrix of n transducers, with i ranging from 1 to n.

(12) Their combination makes it possible to emit high-power ultrasound, and which can be focused by emitting the different transducers simultaneously but with phases different from one another. In such an architecture, each transducer 302 has its own control interface and thus forms an ultrasound device 300 (also called ultrasonic device). These ultrasonic devices form individual ultrasonic elements within an assembly 400 that forms the ultrasonic (or ultrasound) head.

(13) Within an operational ultrasound system 500, all the ultrasonic elements 300 are controlled by a digital system 502, generally a computer associated with a dialog interface, allowing the physician to set the power and the focal point of the ultrasound. These settings are translated by the digital system into individual control of each element of the ultrasound head, in amplitude, frequency and phase. Through a communication bus 504, each of these individual controls is sent to the digital interface 108 of the ultrasonic element 300 that corresponds thereto within the ultrasonic head 500.

(14) For each ultrasonic element 300, this structure simultaneously carries out the control and the supply of the ultrasonic transducer 302 by an analog power signal s.sub.a, which can be qualified as the primary supply signal. This primary signal s.sub.a is generated by a power interface 106, which is controlled by a digital signal forming a drive signal s.sub.p, arising from a generator of square or rectangular multi-level rectangular signals 102.

(15) Each of the generators of digital multi-level square signal or rectangular signals 102 is controlled in frequency F1, in phase 1, or even in amplitude A1, by means of the digital interface 108 corresponding thereto.

(16) The power interface 106 is typically an H half-bridge, and/or a class D amplifier. Typically, it thus emits a primary multi-level square or rectangular supply signal of the same frequency F1 and of the same phase 1.

(17) The ultrasonic transducer 302 is in series with an inductor L1, which makes it possible to filter the harmonics of the multi-level square or rectangular signal and which supplies a sinusoidal signal s.sub.a to the terminals of the transducer 302, which can be qualified as a secondary supply signal. A capacitor C1 is placed in parallel with the transducer 302 using the electronic switch K1. By switching the capacitor C1 during only a determined part of the time, typically during a determined part of each period of the primary signal s.sub.a exiting from the power interface 106, a modification of the impedance of the tuning circuit 104 is obtained, which makes it possible to displace the resonance point (that is to say its resonance frequency F30) of the assembly 301 formed by the inductor L1, the capacitor C1 and the transducer 302, an assembly that can be described as a tuned transducer 301.

(18) It should be noted that the multi-level square or rectangular signal generator 102, the phase comparator 112, the setpoint 110 and its summer 113, the corrector 114 and the output synchronization stage 115 are preferably entirely produced by digital circuits.

(19) FIG. 3 is a schematic depiction 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, and in particular the supply device 100 of FIG. 1.

(20) FIG. 4 is a schematic depiction of a non-limiting exemplary embodiment of an ultrasonic device according to the invention. The ultrasonic head 400 of FIG. 4 comprises n ultrasonic devices 300.sub.1-300.sub.n arranged in parallel and forming a matrix.

(21) At least two of the ultrasonic devices 300.sub.1-300.sub.n may be the same or different from each other.

(22) Each ultrasonic device 300.sub.i may be identical to the ultrasonic device 300 of FIG. 3 and comprises all the elements of the device 300 with the same references that end with subscript i.

(23) FIG. 5 is a schematic depiction of a non-limiting exemplary embodiment of an ultrasound system according to the invention.

(24) The ultrasound system 500 of FIG. 5 comprises an ultrasonic head according to the invention, such as for example the ultrasonic head 400 of FIG. 4.

(25) The ultrasound system 500 further comprises a control apparatus 502, such as a computer or a tablet, and more generally any computer apparatus, connected to each ultrasonic device 300.sub.i from the ultrasonic head 400, and in particular to the control interface 108.sub.i of said ultrasonic device.

(26) In the example shown, the control apparatus 502 is connected to each control interface 108.sub.i through a digital 504 and wired 504 communication. Alternatively and by way of example, each control interface 108.sub.i, or only some of them, may be in communication with the control apparatus 502 through a wireless link.

(27) The control apparatus 502 makes it possible to control each ultrasonic device 300.sub.i individually and independently of the other ultrasonic devices 300.sub.i in order to change the frequency, phase and/or amplitude of the ultrasonic wave emitted by each ultrasonic device 300.sub.i. This makes it possible to adjust, in a simple, dynamic, and responsive manner, the amplitude, frequency, and phase of each ultrasonic wave transmitted by each ultrasonic device 300.sub.i. Consequently, it is possible to simply, flexibly, and responsively adjust the focal point, typically by controlling, for the different elements 300.sub.i, phases that are different but coordinated with one another, as well as the amplitude of the ultrasonic waves emitted by the ultrasonic devices 300.sub.1-300.sub.n.

(28) For example, when the invention is implemented in a medical imaging device, or even therapy, it is thus possible to rapidly and accurately modify the focal point of the waves of the head 400, for example to perform real-time monitoring of the moving members.

(29) FIG. 6 illustrates a variant of FIG. 5, in which the system 600 has a head 406 composed of a plurality of n ultrasonic composite devices 306.sub.1 to 306.sub.n. Within each of these composite ultrasonic devices, for example the one referenced 306.sub.11, a same common interface 108.sub.1 controls a plurality of m supply devices 100.sub.11 to 100.sub.1m, which each supply power to one single transducer 302.sub.11 to 302.sub.1m. In the same way, block 306.sub.n comprises a single digital interface 108.sub.n that directly controls the supply devices 100.sub.n1 to 100.sub.nm transducers respectively 302.sub.n1 to 302.sub.nm.

(30) This makes it possible to produce a digital interface block 108.sub.1 to 108.sub.m, each of which is capable of directly controlling a group of m transducers of the matrix.

(31) The matrix then consists of n.Math.m transducers, which are associated in n groups of m transducers. This number m is not necessarily constant, and can be variable within one subset to the other within the head. In general, this grouping of transducers is small, for example from 2 to 16.

(32) Thus, it is for example possible to increase compactness and number of components in the digital interfaces within the head. It is also possible to produce in an industrial manner a compact, standard subassembly including a digital interface and m transducers, that standard sub-assembly 306 potentially being used in different configurations to produce different types of heads.

(33) Of course, the invention is not limited to the examples just described, and many adjustments can be made to these examples without going beyond the scope of the invention.