Bending structure for medical devices with multiple cut portions

Abstract

The present invention relates to a bending structure for an insertion tube of a medical device, the bending structure comprising a plurality of tubular skeletons (16) for use with a proximal tubular skeleton (16p), a distal tubular skeleton (16d), and at least one drive cable, the drive cable being surrounded by a sheath (13g) over at least a portion of its length, the bending structure comprising a tube cut by a plurality of cutting contours using an energy beam to form the plurality of nested tubular skeletons (16), the proximal tubular skeleton (16p) comprising a radial and axial motion prevention system (40) for the sheath for each drive cable. The radial and axial movement prevention system (40) comprises an elongated cut (41) formed in such a manner as to define two stop ends (41a) that limit the radial engagement of the sheath within the cut, the cut opening at its distal end into a groove (43), the groove (43) being defined by at least two cut lines with a pressing tab (44) between the two cut lines that is designed to radially press the sheath against the two stop ends of the cut, the groove (43) being bordered by a rim (45a) that provides an axial stop for the sheath.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices in the general sense that enables access to the interior of the body, such as cavities or conduits. More specifically, the present invention targets catheter-type medical devices, preferably endoscope-type medical devices.

[0002] The subject matter of the present invention can be particularly advantageously applied to reusable or disposable endoscope applications.

[0003] More specifically, the present invention relates to a bending structure that enables the orientation of the distal head of a medical device of the catheter type or endoscope type, and the distal head is configured to realize a plurality of functions such as visualization, fluid supply, fluid aspiration, instrument supply, sample collection, or provision of surgical procedures.

[0004] A catheter-type or endoscope-type medical device provided with the bending structure of the distal head according to the present invention can be particularly advantageously applied to access the inner surface of a hollow organ, cavity, or natural or artificial conduit of the human body in order to perform various procedures for therapeutic, surgical, or diagnostic purposes.

[0005] The catheter-type or endoscope-type medical device according to the present invention is used for diagnostic, therapeutic, or surgical purposes in the examination of all internal parts of the human body accessible by natural or artificial routes. For example, the catheter-type or endoscope-type medical device according to the present invention can be used in the fields of the urinary tract, digestive tract, respiratory system, cardiovascular system, trachea, nasal sinuses, female genital system, abdominal cavity, or any other part of the human body explored by natural or artificial routes.

Background Art

[0006] Generally, a medical endoscope includes a control handle provided with an insertion tube, as described, for example, in WO 2014 / 106510. This tube includes a distal head provided with an optical vision system for illuminating and examining an organ, cavity or duct of the human body. Upstream of this distal head, the insertion tube includes a bending structure or tip deflection portion formed by indirect articulated vertebrae that enables the orientation of the distal head using one or more drive cables provided within the insertion tube. Each drive cable includes a first end and a second end. The first end is fixed to the distal head. At the second end, a control mechanism provided on the handle operates to effect sliding of the cable, thereby bending this tip deflection portion to orient the distal head.

[0007] In the manufacture of this tip deflection portion, it is necessary to assemble a plurality of skeletons. This results in the difficulty of achieving an interconnected operation and high manufacturing costs. This manufacturing difficulty becomes apparent in many applications where it is necessary to miniaturize the endoscope so that it can pass through an access path with a reduced diameter. In this miniaturization, it is necessary to consider the need to provide various devices within the insertion tube configured to perform various functions, such as fluid supply, fluid aspiration, instrument supply, sample collection, surgical procedures, and passage of connections for the vision system.

[0008] U.S. Patent No. 5,002,041 describes an endoscope in which the tip deflection section of the endoscope includes two nested springs. The two nested springs create a misalignment between a plurality of turns of those springs to form a space for mounting (montage) the cable so that they operate in conjunction. In this way, the cable is guided to translate. In such a solution, the tip deflection section is relatively large-sized, and it is not possible to reduce the cross-sectional area of the endoscope without the risk of adversely affecting (d'alterer) the operation of the device disposed within the insertion tube.

[0009] International Publication No. WO 2014 / 061842 describes an endoscope having a tip deflection section. Specifically, this tip deflection section is formed by a helical spring, and a plurality of concave deformations are provided in a plurality of turns of the spring and are aligned to function as guides for the drive cable. Providing these concave deformations in the spring causes difficulties in manufacturing and high manufacturing costs, especially in the case of an insertion tube having a small diameter.

[0010] Also, in the prior art, in particular, through European Patent Application Publication No. EP 1 604 607, Chinese Patent Application Publication No. CN 107951456 A, Chinese Patent Application Publication No. CN 104605805 A, Chinese Patent Application Publication No. CN 107520273 A, and European Patent Application Publication No. EP 3 195 784, a tube cut by a plurality of cutting contours of an energy beam is used such that a plurality of tubular skeletons nested with each other are formed by a plurality of cut regions forming a plurality of rotating pivots for a plurality of pivot axes, to form a tip deflection section or a bending structure. A plurality of notches are formed in the tube between the plurality of tubular skeletons, and a plurality of bending regions in the plurality of tubular skeletons are formed such that the bending structure bends in at least one bending plane orthogonal to the plurality of pivot axes. Such a bending structure has a low manufacturing cost and, on the other hand, can have a reduced cross-sectional area.

[0011] However, it would be difficult to provide the drive cable at a position suitable for providing the distal head with a tip deflection function over a wide angular range so as to operate in linkage. Note that the drive cable slides within a fixed protective sheath during the tip deflection operation. Therefore, the positioning of the drive cable should, on the one hand, be such that the sliding of the drive cable can cause tip deflection of the bending structure over the entire desired angular range, and on the other hand, the friction with the sheath should be limited.

[0012] In the connection of the bending structure in which the insertion tube is provided on one side and the distal head is provided on the other side, difficulties arise in a complementary manner. Such a connector should be reliable and function well, while having a limited size on the other hand.

Summary of the Invention

[0013] The present invention aims to alleviate the disadvantages of the prior art by proposing a bending structure for a medical device of the catheter type or the endoscope type, which has a low manufacturing cost, can have a reduced cross-sectional area so as to pass through a small-diameter access path without adversely affecting various devices implemented by the endoscope, and can provide a sufficient tip deflection function at the distal head (presenting a low manufacturing cost, being able to present a reduced cross-sectional area for its passage in a small-diameter access path while offering a sufficient bending capacity at the distal head without altering the different apparatuses implemented by this endoscope).

[0014] To achieve the above object, a bending structure for an insertion tube of a medical device comprises a plurality of tubular skeletons, the plurality of tubular skeletons being used together with a proximal tubular skeleton, a distal tubular skeleton, and at least one drive cable surrounded by a sheath over at least a part of its length. The bending structure comprises a tube which is cut by a plurality of cutting contours by an energy beam so as to form a plurality of tubular skeletons nested with each other by a plurality of cut regions forming a plurality of pivots for rotation about a plurality of pivot axes. The plurality of cutting contours are formed so as to partition a plurality of notches cut in the tube between the plurality of tubular skeletons such that a plurality of bending regions in the plurality of tubular skeletons are formed such that the bending structure bends in at least one bending plane orthogonal to the plurality of pivot axes. The proximal tubular skeleton comprises, for each drive cable, a radial and axial movement prevention system for the sheath. The radial and axial movement prevention system comprises a horizontally elongated cut portion formed in such a manner as to define two stop ends restricting the radial engagement of the sheath within the cut portion. This cut portion opens at its distal portion into a groove which is delimited by at least two cut lines and in which a pressing tab is provided between the two cut lines. The pressing tab is designed to radially press the sheath against the two stop ends of the cut portion. This groove is bordered by a rim which stops the sheath axially, against which the distal end of the sheath is pressed.

[0015] Advantageously, the proximal tubular skeleton comprises, at its proximal end, a plurality of connection tabs which extend axially and comprise a radial deformation portion for engagement at the distal portion of the insertion tube.

[0016] In an embodiment, the proximal tubular skeleton comprises, between two adjacent tabs, teeth (comporte entre deux languettes voisines, des dents) which comprise a terminal abutting against the distal end of the insertion tube.

[0017] According to an alternative embodiment, the distal tubular skeleton is provided with a positioning system for the drive cable for welding the drive cable to the distal tubular skeleton, the positioning system comprising a pressing tab and two counter tabs, the pressing tab being formed by cutting the tube with two parallel cutting lines while remaining connected to the tube by a plurality of connection areas at its plurality of ends, the two counter tabs extending on both sides of the pressing tab, each of the two counter tabs being formed by cutting the tube with two parallel cutting lines while remaining connected to the tube by a plurality of connection areas at its plurality of ends, the drive cable being positioned between the two counter tabs and the pressing tab before welding, and at least one weld making it possible to couple the drive cable to the pressing tab.

[0018] Advantageously, the distal tubular skeleton is provided with a connection system, the connection system being used with the distal head, the connection system comprising at least two insertion cuts, the at least two insertion cuts being for the fingers of the distal head and being formed to open by means of an engagement groove for the fingers at the distal part, at least one cut having two blocking projections for the fingers of the distal head, the two blocking projections extending on both sides of the engagement groove of this cut.

[0019] In the first embodiment, the tube is cut with a first series of cut regions forming a plurality of rotating pivots so as to form a plurality of first pivot axes, and a second series of cut regions forming a plurality of rotating pivots, the second series of cut regions extending radially opposite to the first series of cut regions, and a plurality of cutting contours are formed so as to delimit at least one first series of notches between the plurality of tubular skeletons and form a plurality of bending regions in the plurality of tubular skeletons so that the bending structure bends in a direction perpendicular to the plurality of first pivot axes (dans un sens de la direction).

[0020] According to the present invention, a plurality of cut regions forming a plurality of rotary pivots cooperate with each other by their thicknesses.

[0021] According to a preferred embodiment, the plurality of tubular skeletons include at least one tab formed by cutting the tube with two parallel cutting lines while remaining connected to the tube by a plurality of connection regions at its plurality of ends, and the tab is recessed into the tube so as to form a mesh-like guide hole for a drive cable.

[0022] Another object of the present invention is to propose an insertion tube of a medical device having a bending structure according to the present invention, wherein the bending structure is fixed to the tube at its proximal end and fixed to a distal head at its distal end.

[0023] Another object of the present invention is to propose a control handle for a medical device, provided with the insertion tube according to the present invention at its distal part.

[0024] Various other features will become apparent from the following description with reference to the accompanying drawings, which show embodiments of the subject matter of the present invention by way of non-limiting examples.

Brief Description of the Drawings

[0025]

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Embodiments for Carrying Out the Invention

[0026] In FIG. 1, by way of example, there is depicted a medical device 1 in the general sense of an endoscope or catheter type, designed to access the interior of the body, such as a cavity or a duct, for example. In a known manner, the endoscope or catheter type medical device 1 comprises an insertion tube 2. The insertion tube 2 has, on one side, a proximal portion 2 that is connected to a control handle 3 1 and, on the opposite side, a distal portion 2 where a distal head 4 is provided 2 . The insertion tube 2 is temporarily or permanently fixed to the control handle 3. This insertion tube 2 has a certain length and a certain degree of bendability and is intended to be introduced into natural or artificial paths in order to achieve various procedures or functions for therapeutic, surgical or diagnostic purposes. The insertion tube 2 is made of a semi-rigid material, has a length suitable for the length of the duct to be examined, and can be from 5 cm to 2 m in length. The insertion tube 2 has various cross-sectional shapes such as square, elliptical or circular. This insertion tube 2 is in contact with tissues, human organs or medical instruments (trocar or probe), is basically intended to be used once or multiple times on a patient, and furthermore is reusable after decontamination, disinfection or sterilization.

[0027] In a preferred exemplary embodiment, the medical device 1 according to the present invention is an endoscope comprising a visual system capable of illuminating and projecting an image of the distal part of the insertion tube 2 at the distal part of the insertion tube 2. Thus, the endoscope comprises a visual system provided within the control handle 3 and advancing through the insertion tube 2 to the distal head 4. Similarly, the medical device 1 further comprises, within the insertion tube 2, an operating or working passage extending from the control handle 3 to the distal head 4 so as to enable the supply of various instruments and / or fluids and / or the suction of fluids.

[0028] In a known manner, the medical device 1 further comprises a control mechanism 5 for orienting the distal head 4 with respect to the longitudinal axis L of the insertion tube 2. For this purpose, the insertion tube 2 comprises, upstream of the distal head 4, a bending structure 6 according to the invention for bending or tip deflection, which enables the orientation of the distal head 4 with respect to the longitudinal axis L of the insertion tube 2.

[0029] The control mechanism 5 can be formed in any suitable way such that the distal head 4 can transition between a rest position (FIG. 2) where the insertion tube 2 is straight and a tip deflection position (FIGS. 7, 8) where the tip deflection part 6 is bent. In a non-limiting example, the control mechanism 5 can correspond to the control mechanism described in French Patent Application Publication No. 3047887. For this purpose, the control mechanism 5 comprises a manual control lever 11 for rotating at least one pivot part. The pivot part is, for example, a pulley 12, and at least one drive cable 13 to be fixed in the insertion tube 2 and fixed to the distal head 4 is fixed thereto. Typically, each drive cable 13 is surrounded by a sheath 13g over at least a portion of its length.

[0030] In the illustrated preferred embodiment, the bending structure 6 comprises a tube 15. The tube 15 is cut by a plurality of cutting contours T by an energy beam such that a plurality of rings or a plurality of tubular skeletons 16 nested with each other are formed by a first series of cut regions 17m, 17f forming a plurality of rotating pivots and also a second series of cut regions 18m, 18f forming a plurality of rotating pivots. The first series of cut regions 17m, 17f extend radially opposite to the second series of cut regions 18m, 18f so as to form a first pivot axis X. Thus, two adjacent tubular skeletons 16 can pivot relative to each other about the first pivot axis X passing through the first series of rotating pivots 17m, 17f and the second series of rotating pivots 18m, 18f. In a known manner, the tube 15 can be considered to have a symmetry plane S in the rest position where a plurality of first pivot axes X extend parallel to each other.

[0031] Advantageously, each series of cut regions comprises, alternately, female cut regions 17f, 18f (zones decoupees femelles) and male cut regions 17m, 18m (zones decoupees males) nested within the female cut regions 17f, 18f. Thus, the tubular skeleton 16 comprises two male cut regions 17m, 18m located opposite each other in the radial direction, and the adjacent tubular skeleton 16 also comprises two female cut regions 17f, 18f located opposite each other in the radial direction, and the two male cut regions 17m, 18m cooperate with the two female cut regions 17f, 18f. Of course, the shape of the male cut regions 17m, 18m matches or is complementary to the shape of the female cut regions 17f, 18f so that relative rotation between two adjacent tubular skeletons 16 is possible and the two adjacent tubular skeletons 16 can be nested.

[0032] It will be appreciated that the plurality of cut regions 17m, 17f, 18m, 18f form a plurality of rotation pivots and cooperate with each other by virtue of their thickness. In other words, the male cut regions 17m, 18m are contacted or pressed against the ends of the female cut regions 17f, 18f by their ends. As shown in the exemplary embodiments depicted in FIGS. 2 - 10, the shape of the male cut regions 17m, 18m is part of a disc that extends at an angle greater than 180° (e.g., 200° - 300°) so as to be nested within a part of a ring or bearing.

[0033] It will be appreciated that the bending structure 6 is realized based on a single tube 15 that extends along a straight longitudinal axis L and preferably has a circular cross-section. The tube 15 has a thickness suitable for being cut throughout its thickness by any type of energy beam known per se, such as a plasma beam, a water jet, or preferably a laser beam. For example, the tube 15 is cut by a CO2 or YAG laser. The tube 15 has a material thickness of 0.05 - 2 mm. The tube 15 has a diameter of, for example, 1 mm - 20 mm.

[0034] Similarly, the tube 15 is made of a material suitable for being cut by an energy beam and, on the other hand, has the mechanical bendability and mechanical strength characteristics required for the bending structure 6. For example, the tube 15 is made of stainless steel.

[0035] As shown in FIGS. 2 and 3, a plurality of cutting contours T are formed in the tube so as to form a series of tubular skeletons 16 in the tube. A series of tubular skeletons 16 are juxtaposed with each other, together with a so-called distal tubular skeleton 16d and a so-called proximal tubular skeleton 16p. Therefore, the bending structure 6 includes a distal tubular skeleton 16d intended to be fixed to the distal head 4 of the medical device at its distal end, and a proximal tubular skeleton 16p intended to be fixed to the proximal end of the insertion tube 2 at its proximal end. For example, the bending structure 6 provided between the tube 2 and the distal head 4 is inserted into a sheath or a protective shell. Preferably, all of the tubular skeletons 16, except for the distal tubular skeleton 16d and the proximal tubular skeleton 16p, have the same width along the longitudinal axis L. For example, these tubular skeletons 16 have a width of, for example, 1 to 25 mm.

[0036] As shown in the exemplary embodiments depicted in FIGS. 2 to 10, a plurality of cutting contours T are formed in the tube 15 such that a first series of notches 20 and a second series of notches 21 are formed which are cut in the tube and extend symmetrically on both sides of the plane of symmetry S so as to form a plurality of bending regions in the plurality of tubular skeletons 16. In other words, the notches 20, 21 are designed to enable the plurality of tubular skeletons to pivot relative to each other around a first pivot axis X along a radial bending plane D orthogonal to the first pivot axis X. The tube structure 6 includes, on one side of the first plane of symmetry S, a first series of notches 20 which are a series of notches 20 that separate the plurality of tubular skeletons 16 in pairs of two (deux a deux), and on the other side of the plane of symmetry S, a second series of notches 21 which are a series of notches 21 that separate the plurality of tubular skeletons 16 in pairs of two.

[0037] Preferably, the first series of notches 20 are formed within the same angular range. Similarly, the second series of notches 21 are formed within the same angular range. Advantageously, the first series of notches 20 and the second series of notches 21 are formed within the same angular range. Advantageously, the first series of notches 20 and the second series of notches 21 are centered on a radial plane D that passes through the diameter of the tube and is perpendicular to the plane of symmetry S.

[0038] From the foregoing description, it is clear that the notches 20, 21 are formed by material removal in the tube 15. Preferably, the first series of notches 20 are constituted by cuts (decoupe) having the same dimensions and shape. Similarly, the second series of notches 21 are constituted by cuts having the same dimensions and shape. Advantageously, the first series of notches 20 and the second series of notches 21 are constituted by cuts having the same dimensions and shape. The first series of notches 20 and the second series of notches 21 are formed by cuts that are horizontally elongated or tapered in shape and are configured to enable relative pivoting about a plurality of first pivot axes X between two adjacent tubular skeletons 16.

[0039] As shown in more detail in FIG. 3, each notch 20, 21 between two adjacent tubular skeletons 16 is a cut formed only at the outer end of one tubular skeleton 16. Of course, each notch 20, 21 between two adjacent tubular skeletons 16 may be a cut formed at the outer ends of the two adjacent tubular skeletons 16.

[0040] In the exemplary embodiments depicted in FIGS. 2 to 10, the tube structure 6 comprises a first series of notches 20 and a second series of notches 21 such that the bending structure bends in two directions orthogonal to the first pivot axis X (dans les deux sens de la direction). Of course, the tube structure may be formed to comprise a single series of notches if a single drive cable 13 is provided in the tube structure 6 such that the bending structure bends in a single direction orthogonal to the first pivot axis X (dans un seul sens de la direction). Further, in the exemplary embodiments depicted in FIGS. 2 to 8, the plurality of tubular skeletons 16 have an indirect relationship only with respect to the first pivot axis X such that the bending structure bends in the orthogonal plane, i.e., the radial bending plane D.

[0041] In other alternative embodiments, a tube structure 6 can be formed that is configured to enable bending in two planes orthogonal to each other using three or four drive cables 13 for the purpose of realizing the left-right and up-down movement of the distal head 4. In FIGS. 9 and 10, an exemplary embodiment is depicted in which the tube 15 is cut so as to include a third series of cut regions 17'm, 17'f that form a plurality of rotation pivots and a fourth series of cut regions 18'm, 18'f that form a plurality of rotation pivots in a plane that is diametrically opposite to the third series of cut regions 17'm, 17'f and orthogonal to the first symmetry plane S, i.e., the diametral bending plane D (Les Figures 9 et 10 illustrent un tel exemple de realisation pour lequel le tube 15 est decoupe pour comporter une troisieme serie de zones decoupees 17'm, 17'f formant des pivots de rotation et par une quatrieme serie de zones decoupees 18'm, 18'f formant des pivots de rotation s'etendant diametralement opposee par rapport a la troisieme serie et selon un plan perpendiculaire au premier plan de symetrie S a savoir le plan diametral de flexion D.). Thus, the two adjacent tubular skeletons 16 provided with the third series of cut regions 17'm, 17'f and the fourth series of cut regions 18'm, 18'f can pivot relative to each other about a second pivot axis Y passing through the third series of rotation pivots 17'm, 17'f and the fourth series of rotation pivots 18'm, 18'f. This second pivot axis Y is orthogonal to the first pivot axis X.

[0042] For example, as depicted in FIGS. 9 and 10, a third series of cut regions 17’m, 17’f and a fourth series of cut regions 18’m, 18’f can be formed in a plurality of tubular skeletons 16 in which a first series of cut regions 17m, 17f and a second series of cut regions 18m, 18f are already provided, or in a plurality of tubular skeletons 16 in which there are no first series of cut regions 17m, 17f and second series of cut regions 18m, 18f. In the example of FIGS. 9 and 10, an alternation of a plurality of tubular skeletons 16, which enables rotation about a first pivot axis X and a plurality of tubular skeletons 16, which enables rotation about a second pivot axis Y, is selected such that a desired bending radius is obtained.

[0043] By forming a plurality of cutting contours such that the bending structure bends in a bending plane orthogonal to the radial bending plane D, in other words in a symmetry plane S, a third series of notches 20’ and a fourth series of notches 21’ are delimited between the plurality of tubular skeletons 16, which are cut in the tube and extend symmetrically on both sides of the radial bending plane D, and a plurality of bending regions are formed in the plurality of tubular skeletons (FIG. 10).

[0044] The third series of cut regions 17’m, 17’f and the fourth series of cut regions 18’m, 18’f have the same characteristics as the first series of cut regions 17m, 17f and the second series of cut regions 18m, 18f. In the illustrated example, the third series of cut regions 17’m, 17’f and the fourth series of cut regions 18’m, 18’f have the same form of implementation, but it is obvious that the third series of cut regions 17’m, 17’f and the fourth series of cut regions 18’m, 18’f may be formed differently from the first series of cut regions 17m, 17f and the second series of cut regions 18m, 18f.

[0045] The third and fourth series of cut regions 17’m, 17’f, 18’m, 18’f form a plurality of rotational pivots and cooperate with each other by their thicknesses. Similarly, the third and fourth series of cut regions 17’m, 17’f, 18’m, 18’f form a plurality of rotational pivots that alternately include female cut regions 17’f, 18’f and male cut regions 17’m, 18’m nested within the female cut regions 17’f, 18’f.

[0046] Generally, as is apparent from the previous description, the tube 15 is cut by a plurality of cutting contours T by an energy beam such that a plurality of tubular skeletons 16 nested with each other are formed by cut regions 17m, 17f, 18m, 18f, 17’m, 17’f, 18’m, 18’f that form a plurality of rotational pivots for two mutually orthogonal pivot axes X, Y. By forming a plurality of cutting contours such that the bending structure bends in at least one bending plane D, S orthogonal to the pivot axes X, Y, notches 20, 21, 20’, 21’ cut in the tube are defined between the plurality of tubular skeletons, and a plurality of bending regions in the plurality of tubular skeletons are formed.

[0047] Thus, the tube structure 6 comprises a series of tubular skeletons 16 which are directly meshed with each other at the cut outer edges and do not require any work for linking these tubular skeletons 16 to operate together (La structure tubulaire 6 comporte ainsi une serie de vertebres tubulaires 16 emboitees les unes dans les autres, directement en sortie de decoupe, sans necessite d'operations de montage des vertebres tubulaires 16 entre elles.). Thus, the plurality of tubular skeletons 16 are connected by meshing with each other. The notches 20, 21, 20', 21' form a plurality of bending regions so that the bending structure bends in at least one radial bending plane D, S orthogonal to the pivot axes X, Y (Figs. 7-10). Since no work is required at all to link the plurality of tubular skeletons 16 to operate together, this tube structure 6 can have a reduced cost and a reduced diameter.

[0048] According to the characteristics of an advantageous embodiment, some of the plurality of tubular skeletons 16 are at least one tab 25 which is formed by cutting the tube 15 by two parallel cutting lines 25a while remaining attached to the tube by a plurality of connection regions 25b (zones d'attache) at its plurality of ends. Each tab 25 recesses into the tube to form a mesh-like guide hole for the drive cable 13 (pour constituer un oeil de guidage pour le cable d'actionnement 13). Therefore, for example, each tab 25 has a portion that bends from the connection region 25b towards the inside of the tube and is connected by a central recess (Fig. 6).

[0049] According to the characteristics of the advantageous embodiments, each tab 25 is formed in an angular range centered on the range in which the adjacent notches 20, 21, 20', 21' extend. Therefore, the tab 25 is centered on the bending plane. For each drive cable 13, a plurality of tabs 25 are formed along the generatrix of the tube so as to realize the guidance of the translation of the drive cable. In the example depicted in FIGS. 2 to 8, each drive cable 13 is guided by three tabs 25. Therefore, the three tubular skeletons 16 are symmetrically arranged on both sides of the symmetry plane S and have two tabs 25 centered on the radial plane D. Of course, the tabs 25 may be formed on a different number of tubular skeletons 16. Similarly, in the illustrated example, the plurality of tubular skeletons 16 provided with the guide tabs 25 are grouped in pairs and separated by one tubular skeleton without guide tabs. It is obvious that the tabs 25 may be formed on the plurality of tubular skeletons 16 according to other distributions. For each of the plurality of drive cables 13 provided in the bending structure 6, it will be understood that a series of tabs 25 are formed along the generatrix of the tube.

[0050] According to the characteristics of another advantageous embodiment, the bending structure 6 comprises a distal tubular skeleton 4d provided with a connection system 28. The connection system 28 is used with the distal head 4 (avec la tete distale 4). The connection system 28 comprises at least two insertion cuts 29 for the fingers (doigts) 4a of the distal head 4. These cuts 29 are formed in the distal tubular skeleton 16d, and each of the cuts 29 opens into the distal part of the distal tubular skeleton 16d via an engagement groove 29c. In the example depicted in FIG. 8, three cuts 29 are formed, thereby defining three engagement grooves 29c that are evenly distributed along the periphery of the distal tubular skeleton 16d. Each groove 29c has a frustoconical cross-section that narrows from the distal part of the distal tubular skeleton 16d towards the bottom of the groove 29c. Also, the distal head 4 comprises at least two fingers 4a, three fingers 4a in the example shown. These fingers 4a project from the proximal end 4p of the distal head 4 and have an angular distribution that matches the distribution of the cuts 29. Each finger 4a is designed to have a frustoconical cross-section that is complementary to the frustoconical cross-section of the engagement groove 29c in the direction of the rounded end 4e. Each finger 4a is configured to engage within the engagement groove 29c until the proximal end 4p of the distal head abuts (butee) against the distal end of the distal tubular skeleton 16d (FIG. 12). Within the cut 29 of the distal tubular skeleton 4d, the engagement of the fingers 4a of the distal head 4 realizes a radial orientation between the bending structure 6 and the distal head 4 and prevents rotation between those two components.

[0051] According to another feature of the connection system 28, at least one cutout 29, in the example shown one cutout 29, is designed to have two blocking projections 29p for the finger-like portion 4a of the distal head. The two blocking projections 29p extend on both sides of the engagement groove 29c and are substantially directed towards the bottom of the cutout 29. During the engagement of the finger-like portion 4a in the engagement groove 29c during translational movement, the projections 29p penetrate the end of the finger-like portion 4a and prevent the movement of the distal head 4 in the extraction direction relative to the bending structure 6. By the cooperation between the projections 29p and the finger-like portion 4a, the axial extraction of the distal head relative to the bending structure 6 is prevented. Therefore, the distal head 4 can be easily and reliably provided on the bending structure 6 according to the present invention. Furthermore, as described above, this distal tubular skeleton 16d provided with the connection system 28 can be realized directly at the cut outer edge without additional manufacturing steps (De plus, comme explique precedemment, cette vertebre tubulaire distale 16d pourvue du systeme d'assemblage 28 peut etre obtenue directement en sortie de decoupe, sans la mise en oeuvre d'etapes supplementaires de fabrication.).

[0052] According to the features of another advantageous embodiment, the bending structure 6 is a distal tubular skeleton 16d as depicted in FIG. 5 and comprises at least one, two in the example shown, ends 13 of the drive cables 13 1 to which are welded. Of course, if three or four drive cables 13 are provided on the bending structure 6, the ends of those drive cables can be welded to the distal tubular skeleton 16d. In a known manner, the drive cables 13 are made of stainless steel. The welding of the ends of the drive cables 13 can be carried out by any suitable method, such as spot welding technology (a technique using the principle of resistance welding), or laser welding. Of course, the ends 13 2 of the drive cables 13 are fixed to the pulleys 12 in any suitable fixing type.

[0053] According to the features of the advantageous embodiment depicted in more detail in FIGS. 12 and 13, the bending structure 6 is a distal tubular skeleton 16d, provided with a positioning system 30 for the drive cable 13 to enable correct welding of the drive cable 13 to the distal tubular skeleton 16d. This positioning system 30 comprises a radially pressing tab 31. The radially pressing tab 31 is formed by cutting the tube with two parallel cutting lines 32 while remaining connected to the tube by a plurality of connection regions 31a at its two ends. The pressing tab 31 retracts into the distal tubular skeleton 16d, enabling the drive cable 13 to be positioned on the outer surface of the pressing tab 31, whereby the drive cable 13 becomes accessible from the outside of the tube 15. More specifically, the drive cable 13 is pressed against this tab 31 by two counter-tabs 33 extending radially on both sides of the pressing tab 31, each of the counter-tabs 33 being formed by cutting the tube with two parallel cutting lines 34 while remaining connected to the tube by a plurality of connection regions 33a at its two ends. These two counter-tabs 33 achieve good contact of the drive cable 13 with the pressing tab 31, thereby enabling efficient welding of the drive cable 13 to the distal tubular skeleton 16d. For example, in FIG. 13, it is shown that the formation of a weld 13s, advantageously by groove welding, enables the drive cable 13 to be joined (fusionner) to the pressing tab 31 of the tube 15. Furthermore, as described above, this distal tubular skeleton 16d provided with the positioning system 30 can be realized directly at the cut outer edge without an additional manufacturing process.

[0054] FIG. 13A depicts an alternative positioning of the drive cable 13 that enables proper welding of the drive cable 13 to the distal tubular skeleton 16d. In this alternative, the drive cable 13 is supported by two counter-tabs 33 that extend radially on either side of the pressing tab 31. The pressing tab 31 is recessed into the distal tubular skeleton so as to press the drive cable 13 against the inner surface of the pressing tab 31. Thus, the pressing tab 31 deforms to ensure that the drive cable 13 is properly positioned prior to welding. Thus, the weld 13s enables the drive cable 13 to be coupled to the pressing tab 31 of the tube 15. Thus, the drive cable 13 is positioned between the plurality of counter-tabs 33 and the pressing tab 31 prior to welding, and at least one weld 13s enables the drive cable 13 to be coupled to the pressing tab 31.

[0055] According to the features of the present invention more specifically depicted in FIGS. 14 to 16, the proximal tubular skeleton 16p includes, for each drive cable 13, an axial and radial movement prevention system 40 for a sheath 13g surrounding each drive cable 13. This axial and radial movement prevention system 40 includes a cut portion 41 formed axially in the proximal tubular skeleton 16p. The cut portion 41 is parallel to the longitudinal axis of the proximal tubular skeleton 16p. This cut portion 41 has a horizontally elongated shape and is defined by two so-called stop ends 41a. These stop ends 41a extend parallel to each other and parallel to the longitudinal axis of the proximal tubular skeleton 16p. The width between the stop ends 41a of this cut portion is determined so as to enable partial engagement of the sheath 13g into the cut portion 41. In other words, this cut portion 41 is designed to define two stop ends 41a that limit the radial engagement of the sheath 13g into the cut portion. As shown in more detail in FIGS. 14 and 15, the sheath 13g contacts the plurality of stop ends 41a along two generatrices of the sheath 13g. This is done such that the portion of the sheath located between these two generatrices is inserted into the cut portion 41. For example, when the sheath 13g abuts against the plurality of stop ends 41a, the sheath 13g extends substantially in the tangential direction of the outer surface of the proximal tubular skeleton 16p by its outermost generatrix. It should be noted that such an arrangement makes effective use of the space within the bending structure 6.

[0056] This cut portion 41 opens into a groove 43 defined by at least two cutting lines 43a at its distal portion. The groove 43 is formed radially within the proximal tubular skeleton 16p so as to define a pressing tab 44 between the two cutting lines 43a. The pressing tab 44 is connected to the proximal tubular skeleton 16p by a plurality of connection regions 44a at its plurality of ends. This pressing tab 44 is recessed within the proximal tubular skeleton 16p so as to enable positioning of the sheath 13g of the drive cable on the outer surface of the pressing tab 44 between the pressing tab 44 and the body of the proximal tubular skeleton 16p. Therefore, the pressing tab 44 is designed to radially press the sheath 13g against the two stop ends 41a of the cut portion 41.

[0057] Furthermore, this groove 43 is bounded by an axial stop rim 45a for the sheath 13g of the drive cable 13. The sheath 13g has a distal end 13d intended to be pressed against the axial stop rim 45a. Note that beyond the distal end 13d of the sheath 13g, there is no sheath 13g on the drive cable 13. Advantageously, the axial stop rim 45a is formed by the radial ends of a notch 45. The notch 45 is formed axially within the proximal tubular skeleton 16p and opens into the groove 43 on the proximal side. This notch 45 is defined by two support ends 45b. The two support ends 45b extend parallel to each other and parallel to the longitudinal axis of the proximal tubular skeleton 16p. These two support ends 45b are connected to each other by the axial stop rim 45a on the distal side. This notch 45 is designed to enable partial engagement of the sheath 13g into the notch 45 and positioning of the distal end 13d of the sheath 13g against the axial stop rim 45a. Therefore, the sheath 13g abuts against the axial stop rim 45a by substantially half of its distal end 13d.

[0058] According to the characteristics of an advantageous implementation example, it should be noted that when the sheath 13g abuts against the axial stop rim 45a, it is possible to weld the sheath 13g to the proximal tubular skeleton 16p while preventing the translation of the sheath 13g (de maniere a). By this action (A cet effet), the weld is formed, for example, on the one hand between the distal end 13d of the sheath 13g and the axial stop rim 45a and / or the support end 45b, and on the other hand between the distal end 13d of the sheath 13g and the stop end 41a of the proximal tubular skeleton 16p.

[0059] Similarly, it should be noted that the pressing tab 44 presses the sheath 13g radially and brings it into contact with the two support ends 45b, thereby realizing the positioning of the distal end 13d of the sheath 13g with respect to the axial stop rim 45a. Typically, the notch 45 and the cut portion 41 are formed on the same extension line. For example, when the sheath 13g abuts against the plurality of support ends 45b, the sheath 13g extends substantially in the tangential direction of the outer surface of the proximal tubular skeleton 16p by its outermost generatrix.

[0060] It should be noted that the axial stop rim 45a may not be defined by the notch 45 as shown, but may be defined by the distal cut portion end that defines the groove 43. Preferably, the proximal tubular skeleton 16p is provided with a tab 25 formed so as to guide the translation of the drive cable 13 between the axial and radial movement prevention system 40 and the distal end of the proximal tubular skeleton 16p.

[0061] From the foregoing description, it is clear that the axial and radial movement prevention system 40 enables correct positioning of the drive cable 13 and limits friction within the sheath 13g. The movement prevention system 40 makes it possible to position the drive cable 13 so that the portion of the drive cable 13 that is translated by the tabs 25 is aligned without bending (Le système de blocage 40 permet de positionner, sans courbure, le câble d'actionnement 13 afin qu'il se trouve aligné avec sa partie qui est guidée en translation par les languettes 25). Further, this movement prevention system 40 contributes to the radial mechanical strength between the insertion tube 2 and the bending structure 6. Additionally, by preventing axial movement of the sheath 13g relative to the axial stop rim 45a, a robust stop is formed that allows large forces to be transmitted to the drive cable (constitue une butée robuste permettant de passer des efforts importants dans le câble d'actionnement).

[0062] According to the features of an advantageous embodiment, the proximal tubular skeleton 16p comprises, at its proximal portion, a plurality of connection tabs 48. The plurality of connection tabs 48 extend axially and have a radially bent nature for engagement within the distal portion of the insertion tube 2, realizing the connection between the insertion tube 2 and the bending structure 6. The tabs 48 are distributed evenly or unevenly at the periphery of the proximal tubular skeleton 16p. For example, the proximal tubular skeleton 16p comprises two sets of two tabs 48 provided on opposite sides in the radial direction. As depicted in FIG. 16, it should be noted that the two tabs 48 of one set are spaced apart from each other so as to enable positioning and guiding of the drive cable 13 therebetween (le positionnement entre elles et le guidage d'un câble d'actionnement 13).

[0063] Each tab 48 has a radially deformable portion 48a. The radially deformable portion 48a is formed, for example, by bending such that the tab extends substantially parallel to the longitudinal axis of the proximal tubular skeleton 16p while the position of the tab is shifted inwardly towards the interior of the proximal tubular skeleton. Due to the radial displacement of the tab 48, the tab can engage within the distal portion of the insertion tube 2 having a diameter substantially the same as the diameter of the proximal tubular skeleton 16p. As shown in more detail in FIG. 17, the proximal tubular skeleton 16p and the insertion tube 2 are flush at the connection position. It should be noted that the connection by the tab provides the advantage that the size is limited while avoiding the addition of additional connecting parts that increase the thickness.

[0064] Preferably, the plurality of tabs 48 are designed such that a toothed body 49 is left between two adjacent tabs. The toothed body 49 is separated from the toothed body 49 by a cut portion 50, which contributes to the bending nature of the tab 48. In the illustrated example, the proximal tubular skeleton 16p comprises two toothed bodies 49. The two toothed bodies 49 extend diametrically opposite and extend on each side where a set of the plurality of tabs 48 is arranged (deux dents 49 s'etendant de facon diametralement opposee et de part d'autre desquelles sont situees les paires de languettes 48). The toothed body 49 extends axially from the proximal tubular skeleton 16p so as to descend as seen from the end of the tab 48 and has a terminal 49a that also delimits the proximal end of the proximal tubular skeleton 16p. Thus, the tab 48 can be engaged within the insertion tube 2 until the terminal 49a of the toothed body abuts against the distal end of the insertion tube 2 (FIG. 17).

[0065] From the foregoing description, it is apparent that the subject matter of the present invention is the insertion tube 2 of the medical device 1, the insertion tube 2 having a bending structure 6, the bending structure 6 being fixed to the insertion tube 2 at its proximal end and to the distal head 4 at its distal end. Advantageously, the distal head 4 is connected to the bending structure 6 by a connection system 28 of the type that effects fixation by protrusion, while the insertion tube 2 is connected to the bending structure using a plurality of connection tabs 48. As described previously, the proximal tubular skeleton 16p and the distal tubular skeleton 16d described above can be realized directly at the cut outer edge without an additional manufacturing process.

[0066] Since the present invention can be variously modified without departing from the scope of the present invention, it is not limited to the described and illustrated examples.

Claims

1. A bending structure (6) for an insertion tube (2) of a medical device (1), comprising a plurality of tubular skeletons (16), said plurality of tubular skeletons (16) including a proximal tubular skeleton (16p), a distal tubular skeleton (16d), and at least one drive cable (13) surrounded by a sheath (13g) over at least a part of its length, and used together, said bending structure (6) comprising a tube (15), said tube (15) being cut by a plurality of cutting contours (T) of an energy beam so as to form a plurality of tubular skeletons (16) nested with each other by a plurality of cut regions (17m, 17f, 18m, 18f, 17'm, 17'f, 18'm, 18'f) forming a plurality of pivots for rotation about a plurality of pivot axes (X, Y), the plurality of cutting contours being formed so as to form a plurality of bending regions in the plurality of tubular skeletons such that the bending structure bends in at least one bending plane (D, S) orthogonal to the plurality of pivot axes (X, Y), a plurality of notches (20, 21, 20', 21') cut in said tube are formed so as to partition between the plurality of tubular skeletons (16), said proximal tubular skeleton (16p) comprising, for each drive cable, a radial and axial movement prevention system (40) for said sheath, said radial and axial movement prevention system (40) comprising a horizontally elongated cut portion (41), said cut portion being formed in a manner partitioning two stop ends (41a) restricting the radial engagement of said sheath within said cut portion, this cut portion opening at its distal part into a groove (43), said groove (43) being partitioned by at least two cutting lines, a pressing tab (44) being provided between said two cutting lines, said pressing tab (44) being designed to press said sheath radially against said two stop ends of said cut portion, said groove (43) being bordered by a rim (45a) stopping said sheath axially, a bending structure (6) against which the distal end (13d) of said sheath is pressed on said rim (45a).

2. The proximal tubular skeleton (16p) includes, at its proximal portion, a plurality of connection tabs (48), the plurality of connection tabs (48) extending axially and including a radially deformable portion (48a) for engagement at the distal portion of the insertion tube (2), the bending structure according to claim 1.

3. The proximal tubular skeleton (16p) includes a dentate body (49) between two adjacent tabs (48), the dentate body (49) including a terminal (49a) that abuts against the distal end of the insertion tube (2), the bending structure according to claim 2.

4. The distal tubular skeleton (16d) is provided with a positioning system (30) for the drive cable (13) for welding the drive cable (13) to the distal tubular skeleton (16d), the positioning system including a pressing tab (31) and two counter-tabs (33), the pressing tab (31) being formed by cutting the tube with two parallel cutting lines while remaining connected to the tube by a plurality of connection regions at its plurality of ends, the two counter-tabs (33) extending on both sides of the pressing tab, each of the two counter-tabs being formed by cutting the tube with two parallel cutting lines while remaining connected to the tube by a plurality of connection regions at its plurality of ends, the drive cable (13) being positioned between the two counter-tabs (33) and the pressing tab (31) prior to welding, and at least one weld (13s) enabling the drive cable (13) to be coupled to the pressing tab (31), the bending structure according to any one of claims 1 to 3.

5. The distal tubular skeleton (16d) is provided with a connection system (28), the connection system (28) being used with a distal head, the connection system (28) including at least two insertion cut portions, the at least two insertion cut portions being for the finger portions (4a) of the distal head and being formed to open by an engagement groove (29c) for the finger portions at the distal portion, at least one cut portion having two blocking protrusions (29p) for the finger portions of the distal head, the two blocking protrusions (29p) extending on both sides of the engagement groove of this cut portion, the bending structure according to any one of claims 1 to 4.

6. In the tube (15), a first series of cut regions (17m, 17f) forming a plurality of rotating pivots and a second series of cut regions (18m, 18f) forming a plurality of rotating pivots are cut so as to form a plurality of first pivot axes (X). The second series of cut regions (18m, 18f) extend radially opposite to the first series of cut regions. A plurality of cutting contours are formed between the plurality of tubular skeletons (16) so as to partition at least one first series of notches (20) and form a plurality of bending regions in the plurality of tubular skeletons, such that the bending structure bends in a direction orthogonal to the plurality of first pivot axes (X). The bending structure according to any one of claims 1 to 5.

7. The plurality of cut regions (17m, 17f, 18m, 18f, 17'm, 17'f, 18'm, 18'f) forming a plurality of rotating pivots have male cut regions and female cut regions, and the male cut regions are contacted or pressed against the ends of the female cut regions by the ends of the male cut regions. The bending structure according to claim 6.

8. The plurality of tubular skeletons (16) include at least one tab (25) formed by cutting the tube with two parallel cutting lines (25a) while remaining connected to the tube by a plurality of connection regions (25b) at a plurality of its ends. The tab (25) retracts into the tube (15) so as to form a mesh-like guide hole for the drive cable (13). The bending structure according to any one of claims 1 to 7.

9. An insertion tube (2) of an endoscope or catheter-type medical device (1), comprising the bending structure (6) according to any one of claims 1 to 8, wherein the bending structure (6) is fixed to the tube at its proximal end and fixed to the distal head (4) at its distal end. Insertion tube (2).

10. A medical device (1) comprising a control handle (3), wherein the insertion tube (2) according to claim 9 is provided at the distal part of the control handle (3). Medical device (1).

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