SOURCE FOR GENERATION OF ULTRASONIC WAVES WITH EXTERNAL THREAD

Description

[0001] The present invention relates to the technical field of apparatus or devices comprising a source for producing ultrasonic waves and used in the therapeutic field and possibly being associated with an ultrasonic probe for echographic imaging of human anatomy.

[0002] The subject of the invention finds a particularly advantageous application in the field of therapy devices comprising a source for producing high-intensity focused ultrasound waves (HIFU).

[0003] The subject of the invention finds another particularly advantageous application in the field of devices for destroying solid intracorporeal concretions for lithotripsy treatments comprising a source for producing ultrasonic pressure waves such as acoustic shock waves making it possible to destroy concretions or renal, biliary or salivary stones.

[0004] Generally speaking, an ultrasonic wave production source comprises a mounting body for an acoustic transducer that converts electrical energy into mechanical energy. This ultrasonic transducer has, towards the front, an emission face delimiting with a flexible membrane, a containment chamber for an acoustic coupling and / or cooling fluid. Conventionally, this flexible membrane is mounted on an annular support of the body using a fixing system of a waterproof and removable nature so that it can be replaced after each use.

[0005] Typically, the flexible membrane is mounted on the annular support using an elastic ring whose restoring force is adapted to exert sufficient force to ensure the sealed mounting of the membrane on the support while allowing the installation of this ring with a manual effort allowing easy installation. In practice, the operation of mounting this flexible membrane proves relatively difficult to carry out to ensure perfect sealing of the confinement chamber around the entire perimeter of the annular support. In addition, this mounting operation sometimes leads to destruction of the ultrasonic transducer by an inadvertent pressure applied by the operator, given the difficulty in installing the elastic ring.

[0006] Patent application EP 2 327 450 describes an ultrasound production probe comprising a removable flexible membrane intended to cover a HIFU head in which a HIFU transducer is mounted. This probe is provided with connection means for providing a detachable attachment between the membrane and the HIFU head. These connection means comprise a circumferential groove made on the inner side of the membrane and engageable with a circumferential rib formed on the outer side of the HIFU head. In a complementary manner, this membrane comprises on its inner face, three peripheral ribs intended to be pressed against the HIFU head to ensure sealing and circulation for the cooling liquid confined between the membrane and the HIFU head.

[0007] It should be noted that the operation of mounting the flexible membrane requires elastic deformation of the membrane to ensure the groove engages in the rib of the head. Even if this membrane is equipped with a pull tab, its installation requires significant manual effort, which is difficult to control to ensure a perfect seal around the entire perimeter of the HIFU head.

[0008] In the field of ultrasound probes, document US 2015 / 0182200 describes an ultrasound probe comprising a probe head connected by a harness to a connector comprising a cooling system ensuring the circulation of a cooling fluid between the probe head and the connector. This cooling system comprises a damper for the pulsations of the fluid pressure created by the pump and detrimental to the quality of the ultrasound images. This vibration damper comprises a flexible membrane mounted to delimit on one side, a chamber for receiving the cooling fluid and on the other side, a closed air chamber. The sealing between the two chambers is ensured by the compression of the membrane sandwiched between the housing and a ring screwed onto the inside of the housing. The pulsations of the cooling fluid are absorbed by the mechanical deformation of the flexible membrane.

[0009] This document is silent on the description of the probe head and on a possible mounting arrangement for a removable membrane defining a containment chamber for the cooling fluid in relation to the ultrasonic transducer.

[0010] The analysis of the prior art leads to the observation that there appears to be a need to be able to have an ultrasonic probe adapted to be equipped with a flexible membrane, without requiring the use of tools or carrying out manipulations that are difficult to carry out. In addition, the ultrasonic transducer which is placed near the opening of the housing receiving this membrane, is likely to be damaged during the installation of this membrane, but also outside the use of the ultrasonic probe. There thus appears to be a need to be able to protect the ultrasonic transducer of the probe both during its use and outside its periods of use, by an effective and simple system to set up.

[0011] It should be noted that the ultrasound probe undergoes calibration operations requiring the implementation of an ultrasound beam alignment system. In addition to the problems of setting up such an alignment system with the ultrasound beam, this calibration operation must be carried out successfully without risk of damage to the ultrasonic transducer.

[0012] The present invention aims to remedy the drawbacks of the state of the art by proposing a new source of production of ultrasonic waves designed to optimize the various interventions likely to occur during its implementation.

[0013] An objective of the present invention is to propose a new source for producing ultrasonic waves designed to facilitate, without risk of deterioration of the ultrasonic transmitter, the operations: installation of the flexible membrane for confining the acoustic coupling fluid and / or cooling; protection of the ultrasonic transducer when the probe is not in use; calibration of the ultrasonic transducer.

[0014] To achieve such objectives, the invention relates to a source for producing ultrasonic waves according to claim 1.

[0015] According to one example, the fixing ring is provided with a washer mounted free to rotate relative to the fixing ring so as not to be driven into rotation during the screwing operation of the fixing ring, this washer exerting a pressure force on the flexible membrane in the screwed position of the fixing ring on the body. Such a device makes it possible to obtain a mounting of the membrane without creases on the housing.

[0016] In addition, the source for producing ultrasonic waves may also comprise in combination one and / or the other of the following additional characteristics: the washer is mounted in the fixing ring with limited lateral movement to exert a pressure force on the flexible membrane in the screwed position of the fixing ring on the body; the washer is held in the fixing ring inside an annular housing of C-shaped section; a seal in contact with the flexible membrane; the washer is equipped with the seal; the washer is made of polytetrafluoroethylene; the thread or the complementary thread can be made in the form of a continuous element or in the form of discontinuous elements such as lugs.

[0017] In another example, where the ultrasonic transducer is to be protected, the body comprises a net cooperating with a complementary net of a protective cover.

[0018] According to another example for which a calibration phase of the ultrasonic transducer must take place, the body comprises a thread cooperating with a complementary thread of an alignment system which can be used in particular during the calibration step.

[0019] The present invention also provides an ultrasonic wave treatment apparatus comprising an ultrasonic wave production source according to one of claims 1 to 10.

[0020] Various other characteristics emerge from the description given below with reference to the appended drawings which show, by way of non-limiting examples, embodiments of the subject of the invention. There Figure 1 is a perspective view of an exemplary embodiment of a source for producing ultrasonic waves implementing the subject of the invention. Figure 2 is an exploded perspective view of an exemplary embodiment of a source for producing ultrasonic waves in accordance with the invention. Figure 3 is a sectional elevation view taken along section III of the ultrasonic wave production source illustrated in Fig. 1 . La Figure 4 is a perspective view showing another exemplary embodiment of a source for producing ultrasonic waves in accordance with the invention. Figure 5 is an exploded perspective view showing an exemplary embodiment of an ultrasonic wave production source according to the invention intended to be equipped with a protective cover. The Figure 6 is an exploded perspective view showing an exemplary embodiment of a source for producing ultrasonic waves in accordance with the invention intended to be equipped with a ring provided with an alignment system.

[0021] As can be seen from the drawings, the subject matter of the invention relates to a source 1 production of ultrasonic waves for the thermal treatment of biological tissues. This source 1which is used more particularly for therapeutic treatment, is part of a therapy device in the general sense not shown but known per se and adapted to carry out the treatment of tissues of a living being by means of ultrasonic waves. According to an advantageous application, this therapy source produces high-intensity focused ultrasound (HIFU). According to another application, this source produces pressure ultrasonic waves such as acoustic shock waves. Of course, this source for producing ultrasonic therapy waves may or may not be associated with an ultrasound imaging probe of human anatomy.

[0022] The source of ultrasonic wave production 1 includes in particular a body 2 support for a transducer 3 comprising one or more ultrasonic transmitters such as, for example, piezoelectric elements. The ultrasonic transmitters of the transducer3 are connected via an amplifier stage to a control circuit delivering signals to activate the ultrasonic transmitters. The control circuit is not described in more detail because its implementation is within the technical knowledge of those skilled in the art. This control circuit thus conventionally comprises a controlled signal generator which is connected to the ultrasonic transmitters via the amplifier stage.

[0023] The transducer 3 has an emission face on the front 4 ultrasonic waves, directed towards an opening 5 fitted into the body 2. Typically, the body 2 or housing is arranged to present a tubular wall 6 forming a collar or neck. This tubular wall 6 of the body is delimited between an external face 6e and an internal face 6i and is provided at its end with an annular rim6a internally delimiting the opening 5.

[0024] Generally speaking, the emission face 4 has an axis of symmetry X corresponding to the axis of propagation of acoustic waves passing substantially through the center of the opening 5. According to an advantageous embodiment variant, the emission face 4 has a focusing geometry, i.e. the ultrasonic waves produced are focused into a focal zone either due to the control mode of the ultrasonic emitters or by the geometric shape of the emission face. Typically, the emission face 4 has a concave shape such as a hemispherical, elliptical or toric shape. Of course, the emitting face 4 may have a shape other than a concave shape such as a plane shape for example.

[0025] The ultrasonic transducer 3is thus positioned directly opposite the opening 5. Typically, the ultrasonic transducer 3 is located at or slightly behind the opening 5.

[0026] Depending on the implementation of the production source 1 in accordance with the invention, this production source 1 is intended to receive various equipment or accessories, each adapted to a specific function.

[0027] When the source 1 is used to produce ultrasonic waves, the source of ultrasonic wave production 1 has a flexible membrane 8 placed in front of the emission face 4 and made of a material transparent to ultrasonic waves. This flexible membrane 8 delimits with the emission face 4, a confinement chamber 10for a cooling fluid capable of also fulfilling an acoustic coupling function with the insonified medium. Typically, the cooling fluid is a liquid based on water previously degassed to improve wave propagation or oil selected from those having acoustic characteristics of low absorption of ultrasonic waves. The liquid described in patent EP 1 038 551 can also be used.

[0028] The Containment Chamber 10 has at least one inlet for the cooling fluid which is supplied by at least one supply pipe 11. The Containment Chamber 10 also includes at least one outlet communicating with an outlet pipe 12 thus allowing circulation of the fluid inside this containment chamber.

[0029] The flexible membrane 8is made of any suitable materials such as silicone or latex or polyurethane or any materials with low acoustic absorption in order to reduce acoustic energy losses linked to the heating of the membrane.

[0030] The flexible membrane 8 is mounted on the body 2 using a fixing system 14 waterproof and removable or detachable. The fixing system 14 allows you to change the flexible membrane quickly and easily at will 8 while restoring the watertightness of the containment chamber 10 after changing the membrane.

[0031] According to the invention, the fixing system 14 includes a fixing ring 15 intended to be assembled to the body 2 in a removable manner. This fixing ring 15 and the body 2are equipped with a threaded assembly system 16, 17 to ensure, by screwing the fixing ring 15 on the body 2, maintaining the flexible membrane 8 in tight support on the body 2.

[0032] As more precisely shown in the Fig. 2 And 3 , the fixing ring 15 is in the form of an annular body comprising an annular upper wall 15d delimiting in its center, a central passage 19 for a part of the flexible membrane 8 and in particular, a central part 8a of this flexible membrane. The flexible membrane 8 and the fixing ring 15 are two rooms independent of each other. Typically, this central passage 19 has a section corresponding substantially to the section of the opening 5so that in the mounted position of the fixing ring 15 on the body 2, the opening 5 and the central passage 19 coincide.

[0033] Typically, the central passage 19 has a circular outline. Of course, the flexible membrane 8 has a suitable or deformable shape to pass through its central part 8a, the central passage 19 and form the containment chamber 10. The central part 8a of the flexible membrane is bordered by a peripheral part 8b intended to cooperate with the body 2 to ensure the containment chamber is sealed 10. More precisely, the peripheral part 8b of the flexible membrane 8 is adapted to rest on the annular rim 6a of the annular wall 6.

[0034] The upper annular wall 15dextends at right angles with a tubular skirt 15j having an internal face 15i and intended to extend in relation to the tubular wall 6 of the body 2, in the mounted position of the fixing ring 15 on the body 2.

[0035] The threaded assembly system 16, 17 of the fixing ring 15 on the body 2 can be made in any suitable manner. Such a threaded assembly system comprises at least one helical rib or thread 17 cooperating with at least one complementary helical rib or complementary thread 16. The net 17 is fitted on the fixing ring 15 or on the body 2 while the complementary net 16 is arranged respectively on the body 2 or on the fixing ring 15. It should be noted that the net 17 or the complementary net16 can be realized as a continuous element ( Fig. 2 ) or in the form of discontinuous elements such as spurs or nipples ( Fig. 4 ). Likewise, the threaded assembly system 16, 17 may have several helical threads 17 and several complementary helical threads 16.

[0036] In the example embodiment illustrated on the Fig. 3 , the body 2 and in particular the tubular wall 6 externally presents at least one net 17 while the fixing ring 15 is provided with an additional net 16 such as tapping. In the example shown in Fig. 4 , the fixing ring 15 is equipped, as an additional net 16, of two spurs 16 coming to cooperate with the net 17to ensure the ring is screwed onto the body. It should be noted that it may be planned to carry out on the external surface of the body 2 and in particular on the tubular wall 6, as a net 17, the spurs with which at least one complementary thread cooperates 16 of the fixing ring 15.

[0037] In the mounted position of the fixing ring 15 on the body 2, the peripheral part 8b of the flexible membrane 8 is interposed between the fixing ring 15 and the body 2 and more precisely the tubular wall 6. Screwing the fixing ring 15 on the body 2 ensures the maintenance of the flexible membrane 8 in tight support on the body 2. For example, the flexible membrane 8 is sized so that its peripheral part 8bis positioned outside the net 17.

[0038] According to an advantageous embodiment characteristic, the fixing ring 15 is provided with a washer 21 free rotation mounting relative to the fixing ring 15. This washer 21 has a hole in its central part 21a passage for the central part 8a of the flexible membrane. The section of this passage hole 21a corresponds approximately to the section of the central passage 19 of the upper annular wall 15d or as in the example shown is greater than this section of the central passage 19 of the upper annular wall 15d. In the mounted position, the inner edge of the washer 21 thus extends back from the inner edge of the upper annular wall 15d of the fixing ring 15.

[0039] This washer 21which has an external annular face 21e and an internal annular face 21i is held in the fixing ring 15 inside an annular housing 22 delimited by the internal face of the upper annular wall 15d and by a rib 15n extending projecting from the inner face 15i of the skirt 15j. The accommodation 22 thus has a C-shaped section. The washer 21 has a transverse displacement limited on one side by the internal face of the upper annular wall 15d on which the external annular face can come into contact 21e and on the other side, by the rib 15n on which the internal annular face can come into contact 21i. The puck 21 has a radial displacement limited by the internal face 15i of the skirt 15j. It should be noted that the rib 15ncan be achieved by tapping 16. So the washer 21 and the fixing ring 15 are linked together by a pivot connection along the axis passing through the axis of symmetry of the washer.

[0040] According to an advantageous embodiment feature, the washer 21 is made from a material with very high non-stick properties such as polytetrafluoroethylene (PTFE or TEFLON) for example.

[0041] The assembly between the washer 21 and the fixing ring 15 can be made in any suitable way. One solution is to make the fixing ring using a known three-dimensional printing technique 15 integrating the washer 21. The puck 21 can also be put in place by deformation within the fixing ring 15.

[0042] It should be understood that in the unmounted position of the fixing ring 15 on the body 2, there is freedom of rotation between the fixing ring 15 and the washer 21. In other words, the fixing ring 15 can rotate on itself without rotating the washer 21 which remains fixed.

[0043] It should be noted that before installing the fixing ring 15, the flexible membrane 8 is positioned to cover by its peripheral part 8b the upper annular wall 6a. When the fixing ring 15 is mounted on the body 2, the washer 21 is not yet in contact with the peripheral part 8b of the flexible membrane 8 which itself is only in contact with the annular rim 6a of the tubular wall 6. When rotating, the fixing ring15 and the washer 21 rotate simultaneously. When the washer 21 is positioned so as to come into contact with the peripheral part 8b, the flexible membrane 8 is then interposed between this washer 21 and the annular rim 6a of the tubular wall 6. La fixing ring 15 then continues its rotational movement while the puck 21 remains fixed relative to the annular rim 6a of the tubular wall 6 and compared to the flexible membrane 8.

[0044] During the assembly operation of the fixing ring 15 on the body 2, the fixing ring 15 is rotated without rotating the washer 21 which thus holds the flexible membrane in place 8 without creasing it. At the end of the screwing stroke of the fixing ring 15,the latter exerts by its annular upper wall 15d, on the outer annular face 21e, a support force locking the washer in position 21 which presses the flexible membrane 8 on the annular rim 6a of the tubular wall 6.

[0045] The puck 21 is mounted in the fixing ring 15 with limited lateral movement to exert pressure on the membrane in the screwed position of the fixing ring 15 on the body 2. In other words, the puck 21 is brought into the final pressure position when screwing in the fixing ring 15 by supporting the internal face of the upper annular wall 15d on the outer annular face 21e of the washer. The screw stroke of the fixing ring 15 depends of course in particular on the pitch of the net 17and the clearance separating the internal face from the annular wall above 15d and the outer annular face 21e of the washer. The lateral movement associated with the radial movement described above, makes it possible to create a space in which the cleaning and decontamination liquids can penetrate and carry out their functions during decontamination and sterilization phases.

[0046] It should be noted that the washer 21 can be in direct contact with the flexible membrane 8 or as in the example illustrated, by means of a flat or annular seal 23 resting on the flexible membrane 8 which rests on the annular rim 6a. According to a preferred embodiment, the seal 23 is mounted on the washer 21. As it emerges from the Fig. 3 , the washer 21 has on its internal annular face21i, a throat 21g mounting for the seal 23.

[0047] When the source 1 is not used to produce ultrasonic waves, the fixing ring 15 can be removed. In the absence of the fixing ring 15, the body 2 can receive a protective cover 30 to protect the ultrasonic transducer 3. As illustrated in the Fig. 5 , the body 2 includes the net 17 or the complementary net 16 cooperating in the absence of the fixing ring 15, with a complementary net respectively 16 or a net 17 of the protective cover 30. This protective cover 30 which is similar in design to the fixing ring 15 also includes a closing wall 31 closing the central passage 19of the fixing ring 15. This protective cover 30 thus comes to be screwed onto the annular wall 6 of the body 2 to protect the ultrasonic transducer 6, outside of its periods of use.

[0048] In the absence of the fixing ring 15 and the protective cover 30, the body 2 is able to receive an alignment system that can be used in particular during a calibration step. During a calibration step, a ring is used 35 analogous to the fixing ring 15, and equipped with an alignment system 36. For example, the alignment system 36 has an arm 37 carried by the ring and equipped at its end with a sensor 38 allowing to measure the acoustic pressure generated by the transducer or to visualize the axis Xpropagation of acoustic waves or the focusing area of ​​the ultrasonic transducer 4. The body 2 includes the net 17 or the complementary net 16 cooperating in the absence of the fixing ring 15 and the protective cover 30, with a complementary net respectively 16 or a net 17 of the ring 35 equipped with the alignment system 36. The mechanical connection thus obtained between the body 2 and consequently the ultrasonic transducer 3, allows alignment on the acoustic axis X or the focusing area of ​​the emitting face 4 the sensor 38 measuring the pressure on the acoustic axis X or indicating its position or that of the focus area.

[0049] It is clear from the above description that the source of production 1 and in particular, the tubular wall 6of the body of the source, is adapted to ensure mounting by screwing, depending on the use of the source, or the fixing ring 15 of the flexible membrane 8, either a protective cover 30 either a ring 35 equipped with an alignment system 36. The assembly and disassembly operations are particularly simple to carry out, without risk of damaging the ultrasonic transducer 3.

[0050] The object of the invention thus proposes an assembly for producing ultrasonic waves comprising a production source 1 in accordance with the invention and as accessories, a fixing ring 15 a flexible membrane, a protective cover 30 and / or a ring 35 equipped with an alignment system 36, each of the accessories including an additional net 16 cooperating with the net 17of the tubular wall 6 from the body of the production source.

Claims

1. An ultrasound production source comprising a body (2) containing an ultrasound transducer (3) presenting in front an emission face (4), the body (2) including an opening (5) defined by a tubular wall (6) and arranged so that the emission face (4) of the ultrasound transducer (3) faces towards the opening (5), the tubular wall (6) being provided externally with at least one thread (17) of a screw thread assembly system for co-operating with at least one complementary thread (16) either of a fastener ring (15) for fastening a flexible membrane (8) on the body, or of a protective cover (30), or of a ring (35) fitted with an alignment system (36), wherein the fastener ring (15) possesses a central passage (19) for passing a portion of the flexible membrane (8), the fastener ring (15), when screwed onto the body, serving to hold the flexible membrane (8) pressed in sealed manner against the body (2).

2. An ultrasound production source according to claim 1, wherein the tubular wall (6) is provided at its end with an annular rim (6a) against which the flexible membrane (8) bears.

3. An ultrasound production source according to claim 1 to 2, wherein the fastener ring (15) is provided with a washer (21) mounted to turn freely relative to the fastener ring (15) so as to avoid being turned while screwing on the fastener ring (15), the washer exerting a pressure force on the flexible membrane (8) when the fastener ring (15) is screwed in position on the body (2).

4. An ultrasound production source according to claim 3, wherein the washer (21) is mounted in the fastener ring (15) with limited freedom to move laterally in order to exert a pressure force on the flexible membrane (8) when the fastener ring (15) is screwed in position on the body (2).

5. An ultrasound production source according to claim 3 or claim 4, wherein the washer (21) is held in the fastener ring (15) inside an annular recess (22) of C-shaped section.

6. An ultrasound production source according to any one of claims 3 to 5, wherein the washer (21) is fitted with a sealing gasket in contact with the flexible membrane (8).

7. An ultrasound production source according to any one of claims 3 to 6, wherein the washer (21) is made of polytetrafluoroethylene.

8. An ultrasound production source according to any preceding claim, wherein the thread (17) or the complementary thread (16) may be made in the form of a continuous element or in the form of discontinuous elements such as studs.

9. An ultrasound production source according to preceding claim 1, wherein the thread (17) of the body (2) co-operates with a complementary thread (16) of a protective cover (30).

10. An ultrasound production source according to claim 1, wherein the thread (17) of the body (2) co-operates with the complementary thread (16) of a ring (35) fitted with an alignment system (36) suitable for use in particular during a calibration step.

11. An ultrasound production assembly comprising an ultrasound production source according to any one of claims 1 to 10 comprising a body having a tubular wall (6) provided externally with at least one thread (17) of a screw thread assembly system, the assembly also comprising, as accessories: a fastener ring (15) for fastening a flexible membrane; a protective cover (30); and a ring (35) fitted with an alignment system (36); each of the accessories including a complementary thread (16) co-operating with the thread (17) of the tubular wall (6) of the body of the production source.

12. Ultrasound treatment apparatus, characterized in that it includes an ultrasound production source (1) according to any one of claims 1 to 10.