(51) Int Cl.: A61N 7/00 ( )

Transcription

1 (19) TEPZZ 7 Z _4B_T (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin 2016/0 (1) Int Cl.: A61N 7/00 ( ) (21) Application number: (22) Date of filing: (4) Endoscopic device for generating acoustic waves with variable focus Endoskopvorrichtung zur Erzeugung von Akustikwellen mit variablem Fokus Dispositif endoscopique destiné à générer des ondes acoustiques à focale variable (84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (43) Date of publication of application: Bulletin 2014/20 (73) Proprietor: STORZ MEDICAL AG 8274 Tägerwilen (CH) (72) Inventor: Goldenstedt, Dr. Cédric 8274 Tägerwilen (CH) (74) Representative: Lohr, Georg Lohr, Jöstingmeier & Partner Patent- und Rechtsanwälte Junkersstraße Puchheim (DE) (6) References cited: US-A US-A US-A US-A EP B1 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 1 EP B1 2 Description Field of the invention [0001] The invention relates to the ablation of pathological tissues, such as tumors, or nodules, through a precise local heating. This is done by applying physical energy radiation e.g. by acoustic waves into the targeted tissue, which is converted into heat therein. As soon as the temperature reaches a certain level of about 80 C, tissue is coagulated and a necrosis develops. Description of the related art [0002] For a non-invasive treatment, in the US 6,379,320 B1, a focused ultrasound source is provided in the tip of an endoscope for radiating radially. The focus spot cannot be adjusted; therefore, the endoscope must be brought close to the region to be treated, which is often not possible. [0003] An endoscope with integrated ultrasound source is disclosed in DE A1. For generating an ultrasound wave, which is focused at a variable distance, a large number of phased-array transducer elements are provided which are driven by individual oscillators. This requires complex electronics, and the power output of the transducer is limited due to acoustic crosstalk between the individual transducer elements [0004] The US patent application publication US 2003/ A1 discloses and intra-body HIFU (High Intensity Focused Ultrasound) applicator, which uses a plurality of ultrasound transducers mounted on a flexible holder. These transducers are transported by an endoscope into the body, but operated outside of the endoscope. Therefore, a significant amount of space is required within the body, which severely limits the application range of this instrument. [000] US 2012/ A1 discloses an ultrasonic scanning apparatus for providing three-dimensional information relating to the eye and precise volumetric information, related to structures associated therewith. [0006] US 200/ A1 discloses ultrasound transducers for imaging and therapy. The transducers have a linear shape and are bent to modify their radius, and therefore to modify the focus point. [0007] US 2003/00182 A1 discloses a method and apparatus for medical procedures using high intensity focussed ultrasound. Ultrasound transducers are disclosed which have a single ultrasound emitter and which may be placed at the outside of body parts. Summary of the invention [0008] The problem to be solved by the invention is to provide an endoscopic HIFU ultrasound applicator, which delivers a high acoustic energy level, has an adjustable focus spot and can be kept within an endoscope. [0009] Solutions of the problem are described in the independent claims. The dependent claims relate to further improvements of the invention. [00] The invention is based on delivering acoustic energy by at least two radiation emitters within an endoscope, whereby at least one radiation emitter is linearly movable relative to another radiation emitter. Both emitters are radiating under different angles into the same direction having an intersection under an intersecting angle outside the endoscope. This intersection defines the focus spot of the ultrasound applicator. By moving at least one radiation emitter, the position of the intersection and therefore the focus spot moves. To achieve a good absorption of the acoustic energy in tissue, preferably a frequency in the range between one and MHz is selected. Due to the invention, the focus spot can be moved and adapted to actual requirements. It may be anywhere between the surface of the endoscope and deep within the surrounding tissue. The maximum depth that may be up to 40 mm. By means of an actuating element like a wire or even a motor or any other actuator, the focus point may be adjusted during treatment. By using a moving focus spot, a certain area of the tissue may be scanned to treat a larger volume. Such a scanning may also be done automatically or at least controlled by a control unit like a computer. Generally, the position of the focus spot may be dynamically controlled by such a control unit and adapted to a predefined and/or required area. For this purpose, the control unit may be connected to an ultrasound and/or x-ray imaging system. [0011] Herein, generally reference is made to an endoscope. It is understood that the invention may also be applied to any kind of similar instruments like a laparoscope, a catheter, or any intraluminal or interstitial probe, which are referred herein also under the term of endoscope. [0012] Furthermore, reference is made to emitters, which may be any kind of acoustic energy sources like any kind of ultrasonic transducers, e.g. Piezo transducers, capacitive or piezoelectric micromachined ultrasound transducers (cmuts and pmuts), piezocomposite transducers, shockwave transducers. An emitter may also be a reflector for reflecting acoustic energy generated by a transducer. [0013] In a first embodiment of the invention, two emitters are provided. A first emitter preferably radiates radially outwards of the endoscope. A second emitter is linearly movable with respect to the first emitter, preferably along the center axis of the endoscope. The beams of radiation of the first emitter and the second emitter are intersecting outside of the endoscope and forming the focus spot. Preferably, the first and the second emitters are transducers. [0014] In a second embodiment, at least one of the emitters is a reflector, while the other emitter is a transducer. Acoustic energy is generated by a transducer directed to the at least one reflector, which diverts the radiation energy outside the endoscope. [001] It is further preferred, if there is a cover, which 2

3 3 EP B1 4 most preferably is of elastic material, for closing an opening within the endoscope sheath over the emitters to allow unattenuated radiation of acoustic energy to the outside of the endoscope. It is further preferred, if an inner volume under the cover is filled with a preferably non or lowabsorbing acoustic fluid. [0016] In a further embodiment of the invention an imaging device, like ultrasound transducer, optical system or elastographic system may be provided within the endoscope. Description of Drawings [0017] In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment with reference to the drawings. Figure 1 Figure 2 Figure 3 Figure 4 Figure Figure 6 Figure 7 shows a first embodiment of an endoscopic device for generating acoustic waves. shows the basic function. shows another embodiment with modified emitters. shows a further embodiment with a reflector. shows an embodiment with two movable and one stationary emitters. shows an embodiment with two movable emitters. shows an endoscope [0018] In figure 1, a first embodiment of an endoscopic device for generating acoustic waves is shown. A first transducer 40 and a second transducer 30 are contained within an endoscope sheath, having an opening to allow the exit of acoustic energy to an outside of the endoscope. The first transducer 40 generates a first beam 1 of acoustic energy, which preferably exits the endoscope under a predetermined angle, preferably under a right angle to the center axis 16 of the endoscope. The second transducer 30 generates a second beam 0 of acoustic energy, which preferably exits the endoscope under an angle different to the exit angle of the first transducer. The first beam 1 and the second beam 0 intersect under an intersecting angle 3 outside of the endoscope at an intersecting point 60, also referred as focus spot. Preferably, the second transducer 30 is mounted to a first slider 20, which may be moved in the direction 17 of the center axis 16 of the endoscope. The slider may contain at least one conduit 21 for liquids and/or electrical lines. There may be a cover 11 covering the opening of the endoscope sheath and further enclosing an inner volume 14, which preferably is filled with an acoustic coupling fluid. Preferably there is at least one sealing 12 for sealing the inner volume at a gap of movement of the first slider 20 against the endoscope sheath. When moving the first slider 20, the inner volume 14 changes. Accordingly acoustic fluid must be filled in or removed, which may be done through the at least one conduit 21. The cover 11 may also be an elastic cover, which may extend or shrink, when the first slider 20 is moved. [0019] In figure 2, the basic function of the endoscope device is shown. The first slider 20 as shown in the previous figure may be moved to second position 22, which is more distant from the first transducer 40 than the first position. From the second position, it radiates a second beam of acoustic energy, basically under the same angle as from the first position. The second beam is intersecting with the first beam 1 of the first transducer under a second intersecting angle 6 resulting in the second focus spot 61. As there was only a linear displacement of the second transducer, the second beam from the second position is parallel to the second beam 0 from the first position. Consequently the second intersecting angle 6 is the same or approximately the same as the first intersecting angle 3. The second focus spot 61 has moved outward from the first focus spot 60. Accordingly, a linear movement of the second transducer 30 by moving the slider 20 results in a preferably radial displacement of the focus spot. The focus spot may also be moved by moving the first transducer and keeping the second transducer fixed or even by moving both transducers. When moving the first transducer, the focus spot not only moves radially, but it also moves laterally in the direction of the center axis 16. [0020] In figure 3, another embodiment with modified radiation sources is shown. Here the radiation sources 40 and 30 are focused transducers emitting narrower beams 1 and 0 resulting in a smaller focus spot 60. Here the energy density at the surface of the endoscope defined by the cover 11 is comparatively low and prevents unwanted effects like coagulation of the tissue at the surface of the endoscope. [0021] In figure 4, a further embodiment with a mirror is shown. Herein the second emitter is a reflector 32. The acoustic energy is generated by a transducer 31, which may be located in the end section 13 of the endoscope. This transducer 31 radiates acoustic energy towards the reflector 32 which itself deflects the acoustic energy into a second beam 0 to form a focus spot 60 together with a first beam 1. The basic function is the same, as if there would be a transducer 30 instead of the reflector 32. [0022] In figure, an embodiment with two movable radiation sources is shown. This embodiment is based on the previous embodiments. Furthermore, a third transducer 70 has been added. This third transducer 70 generates a third beam 2 intersecting first beam 1 under a third intersecting angle 4. The focus spot accumulates the energy of all three beams 0, 1, 2. The third transducer 70 may be supported by a second slider 2, which may also be moved parallel to the center axis 16 of the 3

4 EP B1 6 endoscope. This second slider may be moved for the same amount, but in the opposite direction of the first slider to keep a small focus spot. It may also be used independently of the first slider to form a variable and/or increased focus spot. [0023] In figure 6, a similar embodiment, but without the stationary emitter 40 is shown. This embodiment permits to adjust the position of the focus spot not only radially but also in the whole z-x plane. If the sliders 20 and 2 are moved in opposite directions and of the same quantity, the focus spot moves in the radial direction 63. If the sliders 20 and 2 are moved in the same direction and of the same quantity, the focus spot moves laterally in the direction 62. When moving only one slider, the focus spot not only moves radially, but it also moves laterally. [0024] In figure 7, an endoscope is shown. The endoscope has a sheath defining a center axis 16. There is a proximal end having a handle 1 and a distal end bearing the transducers, which are covered by a cover 11. List of reference numerals [002] endoscope sheath 11 cover 12 ceiling 13 end section 1 handle 14 inner volume 16 center axis 17 direction of movement 18 second direction of movement 20 first slider 21 conduits 22 second position of first slider 2 second slider 30 second emitter 31 transducer 32 reflector 40 first emitter 0 second beam 1 first beam 2 third beam 3 first intersecting angle 4 first intersecting angle second beam from second position 6 second intersecting angle 60 focus spot 61 second focus spot 62 movement of focus spot parallel to x-axis 63 movement of focus spot parallel to y-axis 70 third emitter Claims 1. Endoscopic device for generating acoustic waves, comprising an endoscope having a sheath () and defining a center axis (16), the sheath containing - a first transducer (40) for generating a first beam (1) of acoustic energy radiating outwards of the endoscope sheath () of a predetermined exit angle, - a second transducer (30) for generating a second beam (0, ) of acoustic energy radiating outwards of the endoscope sheath () at an angle different to the exit angle of the first transducer, wherein, in a first position of the second transducer (30), the first beam (1) and the second beam (0) are intersecting at a first intersecting angle (3) outside of the endoscope thus defining a first position of a focus spot (60), wherein the second transducer (30) is mounted to a first slider (20) configured to move the second transducer (30) linearly parallel to the center axis (16) with respect to the first transducer from the first position to a second position so as to displace the second beam () and hence the intersection of the first beam (1) and the second beam (0) to provide a second position of the focus spot (61), wherein, from its second position, the second transducer (30) radiates the second beam () basically at the same angle as from the first position, so that the second beam () is intersecting with the first beam (1) at the same intersecting angle (6) as the first intersecting angle (3). 2. Endoscopic device according to claim 1, a third transducer (70) is provided for generating a third beam (2) of acoustic energy radiating outwards of the endoscope sheath () and intersecting at least with the first beam (1) outside of the endoscope. 3. Endoscopic device according to claim 1, the first transducer (40) is mounted to a second slider (2) which is movable within the endoscope sheath (). 4. Endoscopic device according to claim 2, the third transducer (70) is mounted to a second slider (2) which is movable within the endoscope sheath ().. Endoscopic device according to claim 2 or 4 4

5 7 EP B1 8 the second and the third transducers (30, 70) are movable independent of each other. 6. Endoscopic device according to any one of claims 2, 4 or, the second and the third transducers (30, 70) are movable into the same direction and/or opposite direction. 7. Endoscopic device according to any one of the previous claims, the first transducer (40) is configured to radiate radially. 8. Endoscopic device according to claim 7, the first transducer (40) is configured to radiate at a right angle to the center axis (16) of the endoscope sheath (). 9. Endoscopic device according to any one of the previous claims, the endoscope sheath () has an opening above the transducers (40, 30, 70).. Endoscopic device according to claim 9, the opening above the transducers (40, 30, 70) is covered by a cover (11) enclosing an inner volume (14). 11. Endoscopic device according to claim, the inner volume (14) is filled with an acoustic coupling liquid. 12. Endoscopic device according to one of previous claims, at least one drive means is provided within the endoscope to move the first slider (20). 13. Endoscopic device according to claim 3 or 4, at least one drive means is provided within the endoscope to move the second slider (2). 14. Endoscopic device according to claim 12 or 13, the at least one drive means is configured to perform a continuos movement for scanning a specific region of tissue surrounding the endoscope Patentansprüche 1. Endoskopische Vorrichtung zum Erzeugen von Schallwellen, umfassend ein Endoskop mit einer Hülle () und definierend eine Mittelachse (16), wobei die Hülle enthält - einen ersten Wandler (40) zum Erzeugen eines ersten Strahls (1) von Schallenergie, die nach außen von der Endoskophülle () in einem vorbestimmten Winkel abstrahlt, - einen zweiten Wandler (30), der an einen ersten Gleiter (20) montiert ist, zum Erzeugen eines zweiten Strahls (0, ) von Schallenergie, die nach außen von der Endoskophülle () in einem Winkel verschieden von dem Ausgabewinkel des ersten Wandlers, abstrahlt, wobei in einer ersten Position des zweiten Wandlers (30) der erste Strahl (1) und der zweite Strahl (0) sich an einem ersten Überschneidungswinkel (3) außerhalb des Endoskops überschneiden, um so eine erste Position eines Brennpunktes (60) zu bilden, wobei der zweite Wandler (30) an einen ersten Gleiter (20) montiert ist, welcher konfiguriert ist, um den zweiten Wandler (30) linear parallel zur Mittelachse (16) mit Bezug zum ersten Wandler, von der ersten Position zu einer zweiten Position zu bewegen, um den zweiten Strahl (), und somit die Überschneidung des ersten Strahls (1) und des zweiten Strahls (0) zu verschieben, um eine zweite Position des Brennpunktes (61) bereitzustellen, wobei, von seiner zweiten Position, der zweite Wandler (30) den zweiten Strahl () im Wesentlichen im gleichen Winkel wie von der ersten Position ausstrahlt, so dass der zweite Strahl () sich mit dem ersten Strahl (1) am gleichen Überschneidungswinkel (6) wie dem ersten Überschneidungswinkel (3) überschneidet. 2. Endoskopische Vorrichtung nach Anspruch 1, ein dritter Wandler (70) bereitgestellt ist zum Erzeugen eines dritten Strahls (2) von Schallenergie, die nach außen von der Endoskophülle () abstrahlt und sich zumindest mit dem ersten Strahl (1) außerhalb des Endoskops überschneidet. 3. Endoskopische Vorrichtung nach Anspruch 1, ein erster Wandler (40) an einen zweiten Gleiter (2) montiert ist, welcher innerhalb der Endoskophülle () beweglich ist. 4. Endoskopische Vorrichtung nach Anspruch 2, der dritte Wandler (70) an einen zweiten Gleiter (2)

6 9 EP B1 montiert ist, welcher innerhalb der Endoskophülle () beweglich ist.. Endoskopische Vorrichtung nach Anspruch 2 oder 4, der zweite und der dritte Wandler (30, 70) unabhängig voneinander beweglich sind. 13, das zumindest eine Antriebsmittel bereitgestellt ist, um eine kontinuierliche Bewegung zum Scannen einer spezifischen, das Endoskop umgebenden Geweberegion auszuführen. 6. Endoskopische Vorrichtung nach irgendeinem der Ansprüche 2,4 oder, der zweite und der dritte Wandler (30, 70) in derselben Richtung oder in entgegengesetzter Richtung beweglich sind. 7. Endoskopische Vorrichtung nach irgendeinem der vorhergehenden Ansprüche, der erste Wandler dazu konfiguriert ist, radial abzustrahlen. 8. Endoskopische Vorrichtung nach Anspruch 7, der erste Wandler (40) konfiguriert ist, um in einem rechten Winkel zur Mittelachse (16) der Endoskophülle () abzustrahlen. 9. Endoskopische Vorrichtung nach irgendeinem der vorhergehenden Ansprüche, die Endoskophülle () eine Öffnung oberhalb der Wandler (40, 30, 70) hat.. Endoskopische Vorrichtung nach Anspruch 9, die Öffnung oberhalb der Wandler (40, 30, 70) von einer Abdeckung (11) bedeckt ist, die ein Innenvolumen (14) einschließt. 11. Endoskopische Vorrichtung nach Anspruch, das Innenvolumen (14) mit einer Schallkopplungsflüssigkeit gefüllt ist. 12. Endoskopische Vorrichtung nach irgendeinem der vorhergehenden Ansprüche, zumindest ein Antriebsmittel in dem Endoskop bereitgestellt ist, um den ersten Gleiter (20) zu bewegen. 13. Endoskopische Vorrichtung nach Anspruch 3 oder 4, zumindest ein Antriebsmittel in dem Endoskop bereitgestellt ist, um den zweiten Gleiter (2 zu bewegen Revendications 1. Dispositif endoscopique pour la génération d ondes acoustiques, comprenant un endoscope muni d une gaine () et définissant un axe central (16), laquelle gaine contient - un premier transducteur (40) pour produire un premier faisceau (1) d énergie acoustique rayonnant vers l extérieur de la gaine () de l endoscope selon un angle de sortie prédéterminé ; - un second transducteur (30) monté sur une première coulisse (20) pour générer une second faisceau (0, ) d énergie acoustique rayonnant vers l extérieur de la gaine () de l endoscope selon un angle différent de l angle de sortie du premier transducteur, dans lequel, dans une première position du second transducteur (30), le premier faisceau (1) et le second faisceau (0) se croisent sous un premier angle d intersection (3) à l extérieur de l endoscope et définissent ainsi une première position d un point focal (60), dans lequel le second transducteur (30) est monté sur une première coulisse (20) configurée pour déplacer le second transducteur (30) de façon linéaire parallèlement à l axe central (16) par rapport au premier transducteur de la première position à une seconde position pour déplacer le second faisceau (), et ainsi l intersection du premier faisceau (1) et du second faisceau (0), afin de créer une seconde position du point focal (61), dans lequel, à partir de sa seconde position, le second transducteur (30) émet le second faisceau (), sensiblement sous le même angle qu à partir de la première position, de telle façon que le second faisceau () coupe le premier faisceau (1) sous le même angle d intersection (6) que le premier angle d intersection (3). 2. Dispositif endoscopique selon la revendication 1, caractérisé en ce qu il est prévu un troisième transducteur (70) pour produire un troisième faisceau (2) d énergie acoustique rayonnant vers l extérieur de la gaine () de l endoscope et coupant au moins le premier faisceau (1) à l extérieur de l endoscope. 14. Endoskopische Vorrichtung nach Anspruch 12 oder 3. Dispositif endoscopique selon la revendication 1, ca- 6

7 11 EP B1 12 ractérisé en ce que le premier transducteur (40) est monté sur une seconde coulisse (2) qui peut se déplacer dans la gaine () de l endoscope. 14. Dispositif endoscopique selon la revendication 12 ou 13, caractérisé en ce que l au moins un moyen d actionnement est configuré pour réaliser un mouvement continu afin de balayer une région spécifique de tissus entourant l endoscope. 4. Dispositif endoscopique selon la revendication 2, caractérisé en ce que le troisième transducteur (70) est monté sur une seconde coulisse (2) qui peut se déplacer dans la gaine () de l endoscope.. Dispositif endoscopique selon la revendication 2 ou 4, caractérisé en ce que les second et troisième transducteurs (30, 70) peuvent se déplacer indépendamment l un de l autre. 6. Dispositif endoscopique selon l une quelconque des revendications 2, 4 ou, caractérisé en ce que les second et troisième transducteurs (30, 70) peuvent se déplacer dans la même direction et/ou dans des directions opposées. 7. Dispositif endoscopique selon l une quelconque des revendications précédentes, caractérisé en ce que le premier transducteur (40) est configuré pour émettre dans sens radial. 8. Dispositif endoscopique selon la revendication 7, caractérisé en ce que le premier transducteur (40) est configuré pour émettre à angle droit par rapport à l axe central (16) de la gaine () de l endoscope. 9. Dispositif endoscopique selon l une quelconque des revendications précédentes, caractérisé en ce que la gaine () de l endoscope possède une ouverture au-dessus des transducteurs (40, 30, 70).. Dispositif endoscopique selon la revendication 9, caractérisé en ce que l ouverture au-dessus des transducteurs (40, 30, 70) est couverte par un capuchon (11) renfermant un volume intérieur (14). 11. Dispositif endoscopique selon la revendication, caractérisé en ce que le volume intérieur (14) est rempli d un liquide de couplage acoustique Dispositif endoscopique selon l une quelconque des revendications précédentes, caractérisé en ce qu au moins un moyen d actionnement est prévu dans l endoscope pour déplacer la première coulisse (20). 13. Dispositif endoscopique selon la revendication 3 ou 4, caractérisé en ce qu au moins un moyen d actionnement est prévu dans l endoscope pour déplacer la seconde coulisse (2)

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12 EP B1 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description US B1 [0002] DE A1 [0003] US A1 [0004] US A1 [000] US A1 [0006] US A1 [0007] 12