Flexural structure for medical device, with reinforced support for articulated vertebrae

Abstract

Flexing structure for a medical device, with reinforced support of articulated vertebrae. The invention relates to a flexing structure for an insertion tube of a medical device comprising tubular vertebrae (16) and at least one actuating cable (13) extending in a diametral plane of flexion of the structure, the flexing structure comprising a system for supporting the tubular vertebrae including: - at least one lug extending projecting from male cutouts and engaged in a slot of female cutouts and having two rotation-limiting surfaces, - a pair of hooks (30) extending projecting from the tubular vertebrae, outside the diametral plane of flexion, the hooks each being engaged in a housing (32) formed in an adjacent tubular vertebra and having a retaining stop (34) against which the hook bears. Figure for the abstract: Fig. 4.

Description

Title of the invention: Flexing structure for medical device, with reinforced support of articulated vertebrae Technical field

[0001] The present invention relates to the technical field of medical devices in the general sense allowing access to the interior of a body such as a cavity or a canal for example and it aims more specifically at medical devices of the catheter type and preferably, medical devices of the endoscope type.

[0002] The object of the invention finds a particularly advantageous application for endoscopes of a reusable or single-use nature.

[0003] The present invention relates more specifically to the flexural structure making it possible to orient the distal head of such medical devices of the catheter or endoscope type, this distal head being adapted to ensure multiple functions such as visualization, fluid supply, fluid suction, instrument supply, taking samples or surgical operations for example.

[0004] The medical device of the catheter or endoscope type equipped with the distal head bending structure according to the invention finds particularly advantageous applications for allowing access to the internal surface of a hollow organ, a cavity or a natural or artificial conduit of the human body in order to carry out various operations for therapeutic, surgical or diagnostic purposes. For example, the medical device of the catheter or endoscope type according to the invention can be used in the field of the urinary tract, the gastrointestinal tract, the respiratory system, the cardiovascular system, the trachea, the sinus cavity, the female reproductive system, the abdominal cavity or any other part of the human body to be explored by a natural or artificial route. Prior art

[0005] Generally speaking, a medical endoscope comprises, as described for example by patent application WO 2014 / 106510, a control handle to which an insertion tube is attached. This tube comprises a distal head equipped with an optical viewing system for illuminating and examining the organ, cavity or duct of the human body. Upstream of this distal head, the insertion tube comprises a flexion structure or bending part formed of articulated vertebrae allowing the orientation of the distal head using one or more actuating cables mounted inside the insertion tube. Each actuating cable has a first end attached to the distal head and a second end on which acts a control mechanism fitted to the handle to ensure the sliding of the cables and consequently, the folding of this part of the crutch in order to orient the distal head.

[0006] The manufacture of this crutch part requires the assembly of the vertebrae leading to a difficulty of assembly and a high manufacturing cost. This manufacturing difficulty appears all the more so since in many applications, there appears to be a need to miniaturize such an endoscope to allow its passage in an access route with a reduced diameter. This miniaturization must take into account the need to mount inside the insertion tube, various devices adapted to allow different functions to be carried out such as the supply of fluids, the aspiration of fluids, the supply of instruments, carrying out samples or surgical operations, the passage for the connections of the vision system.

[0007] To satisfy this need, the state of the art, for example by US patent 10,687,695, has proposed to produce the bending part or the flexion structure, using a tube cut by cutting lines of an energy beam to produce tubular vertebrae nested in each other by cut zones forming rotation pivots according to pivot axes. Between the tubular vertebrae are made notches cut in the tube to form flexion zones for the tubular vertebrae in order to obtain the flexion of the flexion structure in at least one flexion plane perpendicular to the pivot axes. Such a flexion structure has a low manufacturing cost while being able to have a reduced cross section.

[0008] This patent proposes to produce sliding surfaces on the tubular vertebrae making it possible to resist forces perpendicular to the pivot axes in order to avoid a disconnection between the vertebrae. In practice, this solution is complex to manufacture, especially for tubular vertebrae having a small diameter, typically less than 10 mm.

[0009] Patent application WO2020135364 describes a flexion structure for an endoscope comprising a series of tubular vertebrae nested within each other by male cut-out zones and female cut-out zones forming rotation pivots. This flexion structure comprises a holding system limiting the rotation of the tubular vertebrae between them between two opposite extreme positions. This holding system comprises, for each pivot, two fingers engaged in grooves and extending two arms extending on either side of the pivot, and projecting from the cut edge of a tubular vertebra. This flexion structure has low torsional resistance given the large cuts made. In addition, this architecture leads to a pivot of limited dimensions which does not allow good radial strength to be obtained, which leads to a significant risk of the vertebrae becoming detached.

[0010] US Patent 10,816,118 describes a flexural structure comprising a series of tubular vertebrae nested within each other by male cut-out areas and female cut-out areas forming rotation pivots. This flexion structure also includes a system for holding the tubular vertebrae together between two opposite extreme positions. This holding system includes two T-shaped arms extending on either side of the vertebrae in the flexion plane of the structure. These two arms project from a tubular vertebra and are each engaged in a housing provided in a neighboring tubular vertebra. Such a holding system makes it possible to reinforce the strength of the structure in a direction perpendicular to the flexion plane of the structure. However, the position of this holding system in the flexion plane leads to an interaction between the arms of the holding system and the control for the flexion of the structure, leading to an alteration of the flexion performance of the structure. Statement of the invention

[0011] The present invention aims to remedy the drawbacks of the state of the art by proposing a flexion structure for a medical device of the catheter or endoscope type, designed to ensure effective maintenance of the tubular vertebrae between them regardless of the direction of the forces exerted on the structure, without altering the flexion performance of the structure.

[0012] To achieve such an objective, the subject of the invention relates to a bending structure for an insertion tube of a medical device, comprising tubular vertebrae with a proximal tubular vertebra and a distal tubular vertebra and at least one actuating cable extending in a diametrical bending plane of the structure, the bending structure comprising a tube with a longitudinal axis, cut by cutting lines of an energy beam to produce tubular vertebrae nested in each other by diametrically opposite male cut zones and diametrically opposite female cut zones forming rotation pivots along pivot axes located in a plane of symmetry,cutting lines being arranged to delimit between the tubular vertebrae notches cut in the tube to form flexion zones for the tubular vertebrae in order to obtain the flexion of the flexion structure in the diametrical flexion plane perpendicular to the pivot axes, the flexion structure comprising a system for holding the tubular vertebrae together between two opposite extreme positions. According to the invention, the holding system comprises: , - at least one ear extending in projection from the male cut-out areas and engaged in a lumen of the female cut-out areas and having two rotation-limiting surfaces located on either side of the plane of symmetry, - a pair of hooks extending projecting from the tubular vertebrae, outside the diametrical plane of flexion and according to an orthogonal symmetry with respect to the longitudinal axis, the hooks each being engaged in a housing provided in a neighboring tubular vertebra and having a holding stop on which the hook rests in the two extreme positions.

[0013] According to an advantageous embodiment, each hook has an L shape with a straight finger curved at its end, on one side.

[0014] For each hook, the curved rectilinear finger has a heel delimiting, opposite the end of the finger, a holding surface intended to cooperate with the holding stop.

[0015] Preferably, for each hook, the holding stop has a flat wall.

[0016] According to an advantageous characteristic of the invention, the holding system is arranged in such a way that for each extreme position between two neighboring tubular vertebrae, on the one hand, the two ears of two diametrically opposite male cut-out zones are supported on the limiting surfaces of the lights located on one side of the plane of symmetry located opposite the direction of flexion and on the other hand, the hook located on the side of this plane of symmetry, is supported on the holding stop.

[0017] According to an exemplary embodiment, two ears extend projecting from each of the male cut-out areas and are each engaged in a lumen of the female cut-out areas and have a first bearing surface and a second bearing surface intended to cooperate with a rotation limiting surface.

[0018] According to an advantageous embodiment characteristic, each lug has at least one bearing surface not passing through the pivot axis and intended to cooperate in an extreme position, with a rotation limiting surface extending along a plane not passing through the pivot axis, so as to fit into one another.

[0019] According to another advantageous embodiment characteristic, each male cut-out zone has a connecting neck with the part forming a rotation pivot.

[0020] Preferably, each female cut-out area is arranged to connect with an extreme edge of the tubular vertebra, using non-pointed reinforcing heels extending on either side of the rotation pivot part and intended to engage in the connecting neck.

[0021] According to a variant embodiment, the holding system comprises, for at least one tubular vertebra, two pairs of tongues arranged symmetrically on either side and outside the diametrical plane of flexion, each being engaged in a groove provided in a neighboring tubular vertebra.

[0022] For example, the tube has a diameter less than or equal to 10 mm.

[0023] Advantageously, the tube has a wall thickness of between 0.05 and 1.5 mm.

[0024] Another object of the invention is to provide an insertion tube for a device medical device of the endoscope or catheter type comprising a bending structure according to the invention, fixed at its proximal end to the tube and at its distal end, to a distal head.

[0025] Another object of the invention is to propose a medical device comprising a control handle equipped at its distal part with an insertion tube in accordance with the invention. Brief description of the drawings

[0026] [Fig-1] [Fig.l] is a schematic general view of a medical device of the type catheter in the general sense equipped with a bending structure in accordance with the invention.

[0027] [Fig.2] [Fig.2] is a top view showing more particularly a preferred example of embodiment of a bending structure according to the invention, in the non-supported position.

[0028] [Fig.3] [Fig.3] is a top view showing more particularly a preferred example of embodiment of a bending structure according to the invention, in the crutched position.

[0029] [Fig.4] [Fig.4] is a side perspective view showing part of a flexural structure according to the invention, in the crutched position.

[0030] [Fig.5] [Fig.5] is a top view showing in detail a part of a flexural structure according to the invention, in the crutched position.

[0031] [Fig.6] [Fig.6] is a perspective view in longitudinal section showing a portion of the interior of a flexural structure according to the invention.

[0032] [Fig.7] [Fig.7] is a side view of a flexural structure according to the invention, in the unsupported position, with cut-out areas.

[0033] [Fig.8] [Fig.8] is a view showing the end of a tubular vertebra forming part of a flexural structure according to the invention.

[0034] [Fig.9] [Fig.9] is a perspective view showing another example of embodiment of a holding system forming part of a bending structure according to the invention.

[0035] [Fig. 10] [Fig. 10] is a top view showing another example of an embodiment of a system for holding a flexion structure in accordance with the invention, in the non-supported position. Description of the embodiments

[0036] The subject of the invention relates to a medical device 1 of the endoscope or catheter type 1 in the general sense designed to access the interior of a body such as a cavity or a canal for example. Conventionally, a medical device 1 of the endoscope or catheter type comprises an insertion tube 2 having on one side, a proximal part 2i connected to a control handle 3 and on the opposite side, a distal part 22 which is equipped with a distal head 4. The insertion tube 2 is temporarily or permanently fixed on the control handle 3. This insertion tube 2 which has a more or less significant length and flexibility is intended to be introduced into a natural or artificial access route in order to carry out various operations or functions for therapeutic, surgical or diagnostic purposes. The insertion tube 2 is made of a semi-rigid material and has a length adapted to the length of the conduit to be inspected and which can be between 5 cm and 2 m. The insertion tube 2 has various cross-sectional shapes such as square, oval or circular. This insertion tube 2 which is in contact with tissues, human organs or medical devices (trocars or probes), is essentially for single or multiple use by a patient or even for reusable use after decontamination, disinfection or sterilization.

[0037] According to a preferred embodiment illustrated in the figures, the medical device 1 according to the invention is an endoscope comprising a vision system capable of illuminating and returning an image of the distal part of the insertion tube 2. The endoscope thus comprises a vision system mounted inside the control handle 3 and penetrating inside the insertion tube 2 as far as the distal head 4. Similarly, the medical device 1 also comprises, inside the insertion tube 2, an operating or working channel extending from the control handle 3 to the distal head 4 to allow the supply of various tools and / or fluids and / or the suction of fluids.

[0038] Conventionally, the medical device 1 also comprises a control mechanism 5 making it possible to orient the distal head 4 relative 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 flexion, folding or bending structure 6 in accordance with the invention allowing the orientation of the distal head 4 relative to the longitudinal axis L of the insertion tube 2.

[0039] The control mechanism 5 may be made in any suitable manner so that the distal head 4 can be moved between a rest position in which the insertion tube 2 including the flexion structure is straight (Figures 2, 7) and a bent position in which the flexion structure 6 is curved (Figures 3, 4, 5). By way of non-limiting example, the control mechanism 5 may correspond to the control mechanism described in patent FR 3 047 887. For this purpose, the control mechanism 5 comprises a manual control lever 11 rotating at least one pivoting part such as a pulley 12 on which is fixed at least one actuating cable 13 mounted inside the insertion tube 2 to be fixed at the distal head 4. Typically, each actuating cable 13 is surrounded by a sheath over at least part of its length.

[0040] According to a preferred embodiment illustrated by the figures, the bending structure 6 comprises a tube 15 with a longitudinal axis L, cut by cutting lines T coming from an energy beam to produce rings or tubular vertebrae 16 nested within each other by a first series of cut zones 17m, 17f forming rotation pivots and by a second series of cut zones 18m, 18f also forming rotation pivots. The cut zones 17m, 17f of the first series extend diametrically opposite with respect to the cut zones 18m, 18f of the second series to form first pivot axes X. Thus, two neighboring tubular vertebrae 16 are adapted to pivot relatively to each other around a first pivot axis X passing through a rotation pivot 17m, 17f of the first series and through a rotation pivot 18m, 18f of the second series.By convention, it is considered that the tube 15 has, at rest, a plane of symmetry S in which the first pivot axes X are located, extending parallel to each other.

[0041] Advantageously, each series of cut-out zones alternately comprises male cut-out zones 17m, 18m nested in female cut-out zones 17f, 18f respectively. Thus, a tubular vertebra 16 comprises two male cut-out zones 17m, 18m located diametrically opposite each other cooperating with two female cut-out zones 17f, 18f arranged in an equally diametrically opposite manner in the adjacent tubular vertebra 16. Of course, the male cut-out shapes 17m, 18m are congruent or complementary to the female cut-out shapes 17f, 18f to allow relative rotation between two neighboring tubular vertebrae 16 and nesting between two neighboring tubular vertebrae 16.

[0042] Each tubular vertebra 16 thus comprises, on the one hand, two male cut-out zones 17m, 18m extending in a superimposed manner from a first external edge 16a of the tubular vertebra and, on the other hand, two female cut-out zones 17f, 18f arranged in a superimposed manner from a second external edge 16b of the tubular vertebra, opposite the first external edge 16a.

[0043] It should be understood that the cut-out areas 17m, 17f, 18m, 18f forming rotation pivots cooperate with each other by their thickness. In other words, a male cut-out area 17m, 18m is in contact or in support by its edge with the edge of the female cut-out area 17f, 18f. As is apparent from the embodiment illustrated in Figures 2 to 10, the male cut-out shapes 17m, 18m comprise, as a part forming a rotation pivot, portions of discs with an angular extent greater than 180° (for example between 200° and 300°) to be fitted into portions of rings or bearings.

[0044] According to a preferred embodiment, each male cut-out zone 17m, 18m has a connecting neck 17c with the portion of a disc forming a rotation pivot ([Fig.5]). Preferably, this connecting neck 17c has a constant width extending over a height suitable for placing the portion of disc forming a rotation pivot, in a position spaced apart from the first external edge 16a. According to this embodiment, each female cut-out zone 17f, 18f is arranged to connect with the second extreme edge 16b of the tubular vertebra, using non-pointed reinforcing heels 16t extending on either side of the portion forming a rotation pivot and intended to engage in the connecting neck 17c. It should be understood that each female cut-out zone 17f, 18f does not connect with the second extreme edge 16b of the tubular vertebra, with a pointed zone to prevent this zone from becoming blunt during maximum flexion of the structure. These reinforcing heels 16t thus prevent the tubular vertebrae from becoming detached during repeated flexion stresses.

[0045] It should be understood that the bending structure 6 is obtained from a single tube 15 extending along a rectilinear longitudinal axis L and having a preferably circular cross-section. The tube 15 has a thickness suitable for being able to be cut over its entire thickness by an energy beam of any type known per se, such as a plasma beam, a water jet or preferably by a laser beam. For example, the tube 15 is cut by CO2 or YAG laser. The tube 15 has a wall thickness of between 0.05 and 1.5 mm. The tube 15 has a diameter preferably less than or equal to 10 mm and for example between 1 mm and 10 mm.

[0046] Similarly, the tube 15 is made of a material suitable for being cut by an energy beam while having the mechanical characteristics of bending and mechanical resistance necessary for the bending structure 6. For example, the tube 15 is made of stainless steel.

[0047] As can be seen from Figures 2 and 3, the cutting lines T are arranged to form in the tube a series of tubular vertebrae 16 juxtaposed with each other, with a tubular vertebra called distal 16d and a tubular vertebra called proximal 16p. The flexion structure 6 thus comprises at its distal end a distal tubular vertebra 16d intended to be fixed to the distal head 4 of the medical device and at its proximal end a proximal tubular vertebra 16p intended to be fixed to the distal end of the insertion tube 2. For example, the flexion structure 6 mounted between the tube 2 and the distal head 4 is inserted inside a protective sheath or envelope. These tubular vertebrae 16 have a length taken along the longitudinal axis of, for example, between 2 mm and 15 mm.

[0048] As is apparent from the embodiment illustrated in Figures 2 to 10, cutting lines T are arranged in the tube 15 to produce a first series of notches 20 and a second series of notches 21 cut in the tube extending symmetrically on either side of the plane of symmetry S to form flexion zones for the tubular vertebrae 16. In other words, the notches 20, 21 are arranged to allow the tubular vertebrae to pivot between them around the first pivot axis X, according to a diametrical plane D of flexion perpendicular to the first pivot axis X. The tubular structure 6 thus comprises on one side of the first plane of symmetry S, the notches 20 of the first series separating two by two the tubular vertebrae 16 and on the other side of the plane of symmetry S, the notches 21 of the second series separating two by two the tubular vertebrae 16.

[0049] It is clear from the above description that the notches 20, 21 are made in the tube 15 with a removal of material. Each notch 20, 21 between two adjacent tubular vertebrae 16 results from a cut made to produce the first external edge 16a of a tubular vertebra and the second external edge 16b of the neighboring tubular vertebra 16. When the flexion structure 6 is flexed, in a direction perpendicular to the pivot axes X, the part of the first external edges 16a of the tubular vertebrae delimited by the first series of notches 20 come into abutment in the extreme flexion position, against the part of the second external edges 16b of the neighboring tubular vertebrae 16 delimited by this first series of notches 20.Of course, during the flexion of the flexion structure 6, in a direction opposite to the direction perpendicular to the pivot axes X, the part of the first external edges 16a of the tubular vertebrae delimited by the second series of notches 21 come into abutment in the extreme flexion position, against the part of the second external edges 16b of the neighboring tubular vertebrae 16 delimited by this second series of notches 21.

[0050] The notches 20 of the first series are made according to an angular extension range which is identical or variable to allow the orientation pitch of the vertebrae to be adjusted with respect to each other, i.e. the shape of the flexion structure. Similarly, the notches 21 of the second series are made according to an angular extension range which is identical or not. For example, the notches 20 of the first series and the notches 21 of the second series are made according to an identical angular extension range. Advantageously, the notches 20 of the first series and the notches 21 of the second series are centered relative to the diametrical plane D passing through the diameter of the tube and perpendicular to the plane of symmetry S.

[0051] The notches 20 of the first series are made with a cut that is identical or not in dimensions and shape. Similarly, the notches 21 of the second series are made with a cut that is identical or not in dimensions and shape. Advantageously, the notches 20 of the first series and the notches 21 of the second series are made with a cut that is identical in dimensions and shape. The notches 20 of the first series and the notches 21 of the second series are made by cuts of oblong or tapered shape, adapted to allow relative pivoting between two adjacent tubular vertebrae 16 along the first pivot axes X.

[0052] In the embodiments illustrated in Figures 2 to 10, the tubular structure 6 comprises a first series of notches 20 and a second series of notches 21 to obtain the bending of the bending structure in both directions of the direction perpendicular to the first pivot axis X. Of course, it may be provided to produce a tubular structure comprising a single series of notches in the case where the tubular structure 6 is provided with a single actuating cable 13 to obtain the bending of the bending structure in a single direction of the direction perpendicular to the first pivot axis X.

[0053] In the embodiments illustrated in Figures 2 to 10, the tubular vertebrae 16 are articulated along only the first pivot axis X in order to obtain the flexion of the flexion structure in a perpendicular plane, namely the diametrical flexion plane D. According to this example, the tubular structure 6 comprises two actuating cables 13 located in the diametrical flexion plane D. As shown in the drawings, the two actuating cables 13 are mounted inside the tube 15, being arranged on either side of the longitudinal axis of the tube, close to the walls of the tube.

[0054] Of course, it may be provided to produce a tubular structure 6 adapted to allow flexion in two mutually perpendicular planes using three or four actuating cables 13 in order to obtain the left-right and up-down movement of the distal head 4. According to this alternative embodiment, the tube 15 is cut to comprise a third series of cut zones forming rotation pivots and by a fourth series of cut zones forming rotation pivots extending diametrically opposite with respect to the third series and along a plane perpendicular to the first plane of symmetry S, namely the diametrical flexion plane D. This alternative embodiment is not described in more detail because it follows directly from the preceding description.

[0055] According to the invention, the flexion structure 6 comprises a system 23 for holding the tubular vertebrae together between the two opposite extreme positions that can be taken during the flexion of the flexion structure. In other words, this holding system 23 makes it possible to keep the tubular vertebrae 16 attached together over the entire amplitude of flexion while limiting this flexion in both directions of the direction perpendicular to the first pivot axis X, in two opposite extreme positions.

[0056] The holding system 23 according to the invention comprises at least one finger or ear 26 extending projecting from the male cut-out areas 17m, 18m and having a first bearing surface 26a and a second bearing surface 26b. Each ear 26 is engaged in a slot 27 arranged in the female cut-out areas 17f, 18f and having a first and a second surface 27a, 27b of li limitation of rotation around the pivot axis X. The first and second rotation-limiting surfaces 27a, 27b are located on either side of the plane of symmetry S to block the bending of the bending structure 6 in two opposite extreme positions. According to the embodiment variant illustrated in [Fig. 10], each male cut-out area 17m, 18m is provided with a single ear 26 engaged in a single slot 27 while according to the embodiment variant illustrated in FIGS. 2 to 9, each male cut-out area 17m, 18m is provided with two ears 26 extending projecting from each of the male cut-out areas 17m, 18m and each engaged in a slot 27 of the female cut-out areas 17f, 18f and having a rotation-limiting surface.

[0057] According to the embodiment variant illustrated in Figures 2 to 9, each male cut-out zone 17m, 18m has a first lug 26 having the first bearing surface 26a and a second lug 26 having the second bearing surface 26b. These first and second bearing surfaces 26a, 26b are intended to come into contact with respectively the first surface 27a for limiting rotation around the pivot axis X and the second surface 27b for limiting rotation around the pivot axis X.Thus, one of the lugs 26 of a male cut-out zone 17m, 18m is intended to come into contact by its first bearing surface 26a, with the first surface 27a for limiting the rotation around the pivot axis X, during rotation in a first direction while the other lug 26 of the male cut-out zone 17m, 18m is intended to come into contact by its second bearing surface 26b, with the second surface 27b for limiting the rotation around the pivot axis X, during rotation in a second direction opposite to the first direction of rotation.

[0058] According to the embodiment variant illustrated in [Fig. 10], each lug 26 of a male cut-out zone 17m, 18m has two bearing surfaces 26a, 26b arranged on either side of the lug which is engaged in a slot 27 delimited on either side by the first and second rotation limiting surfaces 27a, 27b. The first bearing surface 26a of these lugs is intended to come into contact with the first surface 27a for limiting rotation about the pivot axis X, during rotation in a first direction while the second bearing surface 26b is intended to come into contact with the second surface 27b for limiting rotation about the pivot axis X, during rotation in a second direction opposite to the first direction of rotation.

[0059] It is clear from the above description that for the lug(s) 26 of each male cut-out area 17m, 18m, the two rotation-limiting surfaces 27a, 27b are located on either side of the plane of symmetry S so that one of the limiting surfaces blocks rotation in one direction while the other limiting surface blocks rotation in the other direction. In other words, the bending of the bending structure 6 is limited in the diametrical plane of flexion D according to the two directions of the direction perpendicular to the first pivot axis X, namely for example, up-down or left-right.

[0060] According to an advantageous characteristic, for each extreme position between two neighboring tubular vertebrae, the two ears 26 of the two diametrically opposed male cut-out zones 17m, 18m bear on the limiting surfaces 27a or 27b of the slots 27 located on one side of the plane of symmetry S, this side of the plane being located opposite the direction of flexion. By convention, the side of the plane of symmetry S, located opposite the direction of flexion is called the external side while the side of the plane of symmetry S, located on the side of the direction of flexion is called the internal side.In the example illustrated in Figures 3 to 5, the direction of flexion of the flexion structure 6 is the right side (internal side) of the flexion so that the part of the first external edges 16a of the tubular vertebrae delimited by the first series of notches 20 are in abutment in the extreme flexion position called the right side, against the part of the second external edges 16b of the neighboring tubular vertebrae 16 delimited by this first series of notches 20. In the extreme flexion position called the right side, the two ears 26 of two diametrically opposite male cut-out zones 17m, 18m of the same tubular vertebra are supported by their first support surfaces 26a, on the first limiting surfaces 27a of the slots 27 located on the left or external side of the plane of symmetry S ([Fig.4]).

[0061] Of course, when the direction of flexion of the flexion structure 6 is the left side of the flexion, the part of the first external edges 16a of the tubular vertebrae delimited by the second series of notches 21 are in abutment in the extreme flexion position called the left side, against the part of the second external edges 16b of the neighboring tubular vertebrae 16 delimited by this second series of notches 21. In the extreme flexion position called the left side, the two ears 26 of two diametrically opposite male cut-out zones 17m, 18m of the same tubular vertebra are in abutment on the second limiting surfaces 27b of the slots 27 located on the right or external side of the plane of symmetry S.

[0062] Each light 27 is advantageously arranged in a female cut-out zone 17f, 18f according to an annular sector centered on the pivot axis X. Thus, each light 27 is delimited by a guide edge 27g centered on the pivot axis X and arranged to serve as a guide for the end edge 26e of the lug 26. Thus, each lug 26 cooperates by its end edge 26e with the guide edge 27g, thus completing the effect of the rotation pivots.

[0063] According to an advantageous embodiment characteristic, the ears 26 have a first bearing surface 26a and a second bearing surface 26b not passing through the pivot axis X. This first bearing surface 26a and this second surface support 26b are intended to cooperate in an extreme position, respectively with a rotation limiting surface 27a, 27b extending along a plane N not passing through the pivot axis X ([Fig.5]). Such an arrangement allows the ear 26 and the female cut-out zone 17f, 18f to fit into each other, promoting their anchoring.

[0064] According to another characteristic of the invention, the holding system 23 according to the invention also comprises a pair of hooks, namely a first hook 30 and a second hook 31, extending in projection from the tubular vertebrae 16, outside the diametrical plane of flexion D and according to an orthogonal symmetry with respect to the longitudinal axis L. A tubular vertebra 16 is thus provided with a first hook 30 and a second hook 31 forming a pair. Each hook 30, 31 of a pair belonging to a tubular vertebra is engaged in a housing, respectively a first housing 32 and a second housing 33, arranged in a neighboring tubular vertebra 16. Each housing 32, 33 has a holding stop 34 on which the hook comes to bear in one of the two extreme positions as defined previously.More specifically, the hook of a pair 30, 31 bears against a holding stop 34 in one of the two extreme positions while the other hook of the pair 30, 31 bears against a holding stop 34 in the other of the two extreme positions, as will be described in detail in the remainder of the description. In the illustrated embodiment, the hooks 30, 31 extend in the extension of the tubular vertebrae, projecting from the first extreme edge 16a of the tubular vertebrae while the housings 32, 33 are arranged from the second extreme edge 16b of the tubular vertebrae.

[0065] According to a characteristic of the invention, each hook 30, 31 has an L shape with a rectilinear finger 36 of constant section, curved at its end, for example at a right angle on one side while remaining in the plane of extension of the rectilinear finger ([Fig.7]). For each hook 30, 31, the rectilinear finger 36 has at its free end, a heel 37 delimiting opposite the end 37a of the finger, a holding surface 37b extending in the example illustrated perpendicular to the rectilinear finger 36. It should be noted that the heel can be curved beyond a right angle so that the holding surface 37b forms with the rectilinear finger, an acute angle promoting hooking. As can be seen from the drawings, for each hook 30, 31, the end 37a of the finger has, for example, a wall in the shape of an arc of a circle while the holding surface 37b has a flat wall.

[0066] For each pair of hooks 30, 31 equipping a tubular vertebra 16, the first hook 30 is located along a first side of the plane of symmetry S while the second hook 31 is located along a second side of the plane of symmetry S, opposite the first side. For one of the two extreme positions of the vertebrae, the first hook 30 is in supported by its holding surface 37b, on the holding stop 34 of the first housing 32 while for the other of the extreme positions, the second hook 31 is supported by its holding surface 37b, on the holding stop 34 of the second housing 33. Preferably, the holding surface 37b and the holding stop 34 have complementary or congruent surfaces.

[0067] It is recalled that in the example illustrated in Figures 3 to 5, the direction of flexion of the flexion structure 6 is the right side (internal side of the flexion) so that the part of the first external edges 16a of the tubular vertebrae delimited by the first series of notches 20 are in abutment in the extreme flexion position called the right side, against the part of the second external edges 16b of the neighboring tubular vertebrae 16 delimited by this first series of notches 20. In the extreme flexion position called the right side, the first hooks 30 located relative to the plane of symmetry S, on the side located opposite the direction of flexion are in abutment on the holding stop 34 ([Fig.4]). In other words, the first hooks 30 located on the external side are in abutment by the holding surface 37b, on the holding stop 34.Conversely, in the extreme flexion position called the left side, the second hooks 31 located relative to the plane of symmetry S, on the side located opposite the direction of flexion, are supported on the holding stop 34. The second hooks 31 located on the external side are supported on the holding stop 34, by the holding surface 37b.

[0068] It is clear from the above description that the holding system 23 is arranged so that for each extreme position between two neighboring tubular vertebrae, on the one hand, the two ears 26 of two diametrically opposite male cut-out zones 17m, 18m of a tubular vertebra are supported on the limiting surfaces 27a, 27b of the slots located on one side of the plane of symmetry S located opposite the direction of flexion and on the other hand, the hook 30, 31 located on the side of this plane of symmetry, is supported on the holding stop 34. It therefore appears that for each extreme position, the holding system 23 implements for two neighboring tubular vertebrae 16, three additional points of contact located on the external side of the flexion structure, thus avoiding a detachment of the tubular vertebrae from each other.

[0069] Each housing 32, 33 is open in the second extreme edge 16b, by respectively, a narrowed portion 39 for guiding the rectilinear finger 36 of the hooks. The heel 37 of each hook is engaged in a housing 32, 33 delimited on the one hand, on the side furthest from the second external edge 16b of the vertebra, by a bottom 40 of the housings 32, 33, in the shape of an arc of a circle and on the other hand, on the side closest to the second external edge 16b, by the holding stop 34 connecting to the outlet of the narrowed portion 39. Each housing 32, 33 is also delimited between the bottom 40 and the holding stop 34, by two guide edges 41 for the heel during its sliding. Thus, each housing 32, 33 has a substantially rectangular extending by the narrowed part 39 of rectangular shape also.

[0070] According to a characteristic of the invention, the hooks 30, 31 of a pair extend from each tubular vertebra, according to an orthogonal symmetry with respect to the longitudinal axis L. Thus, as is apparent for example from [Fig.8], the two hooks 30, 31 of a pair are identical in shape and dimensions but the heels 37 are diametrically oriented in opposite directions. For example, the heel 37 of the first hook 30 extending from the extreme vertebra of [Fig.8] is oriented towards the bottom of the figure while the heel 37 of the second hook 31 extending from the extreme vertebra of [Fig.8] is oriented towards the top of the figure. The heels 37 of the hooks 30, 31 of a pair attached to a tubular vertebra are oriented in the same direction, according to a direction of rotation around the longitudinal axis L.

[0071] This pair of hooks 30, 31 is located symmetrically on either side of the longitudinal axis L, being positioned outside the diametrical plane of flexion D along which the actuating cables 13 are centered. The hooks 30, 31 are not located in the diametrical plane of flexion D to be thus spaced from the actuating cables 13 so as not to interfere in the operation of the actuating cables 13. Thus, as shown in the figures, for each pair of hooks 30, 31 associated with a tubular vertebra, one of the hooks 30 is positioned on one side of the plane of symmetry S while the other hook 31 is positioned on the other side of the plane of symmetry S.

[0072] It should be noted that one of the hooks of a pair is positioned on one side of the diametrical plane of flexion D while the other hook of said pair is positioned on the other side of the diametrical plane of flexion D. According to an advantageous embodiment characteristic, the hooks 30, 31 are arranged from one tubular vertebra to the other alternately on either side of the diametrical plane of flexion D. Thus, as is apparent for example from [Fig. 4], for the hooks 30, 31 located on one side of the plane of symmetry S (the one visible in the drawing), the hooks 30 are alternately, from one tubular vertebra 16 to the other, located below and above the diametrical plane of flexion D. It should be noted that the orientation of the heels 37 of the hooks changes direction from one tubular vertebra to the other. For example, for the hooks 30 located on the side of the plane of symmetry S visible in [Fig.4], the heels 37 of the hooks located above the diametrical plane of flexion D are oriented towards the bottom of the figure while the heels 37 of the hooks located below the diametrical plane of flexion D are oriented towards the top of the figure.

[0073] Similarly, for the hooks located on the other side of the plane of symmetry S (the one not visible in [Fig.4] but visible through the cut-out parts of [Fig.7]), the hooks 31 are alternately, from one tubular vertebra to the other, located respectively above and below the diametrical plane of flexion D. This crossed distribution of the hooks 30, 31 makes it possible to distribute the areas for holding the vertebrae between them, promoting the holding of the vertebrae in different directions when applying forces to the tube 15.

[0074] According to an advantageous embodiment variant, the holding system 23 comprises, for at least one tubular vertebra 16, two pairs of tongues 42 arranged symmetrically on either side of the plane of symmetry S ([Fig.9]). Thus, one pair of tongues 42 is arranged on one side of the plane of symmetry S while the other pair of tongues 42 is arranged on the other side of the plane of symmetry S. Each tongue 42 has a rectilinear shape made parallel to the longitudinal axis L of the tube 15 and intended to cooperate with a groove 43 of complementary shape. The tongues 42 extend projecting from an external edge of a vertebra, outside the diametral plane of flexion D, each being engaged in a groove 43 arranged in the neighboring tubular vertebra. The tongues 42 and the grooves 43 are thus arranged so as not to interfere with the actuation cables 13.For example, the two pairs of tabs 42 are arranged on the proximal tubular vertebra 16p and / or on the distal tubular vertebra 16d and / or on tubular vertebrae not comprising the hooks 30, 31. .

[0075] Advantageously, to hold the actuating cables 13 in position inside the tube 15 ([Fig.9]), certain tubular vertebrae 16 comprise a holding tab 45 cut from the tube by two parallel cutting lines 46 while remaining attached to its ends. This holding tab 45 is pushed back inside the tube 15 to constitute a guide eye for the actuating cable 13. Of course, as illustrated in the drawings, the holding tabs 45 can be arranged in tubular vertebrae located between the proximal tubular vertebra and the distal tubular vertebra and not comprising a holding system 23 according to the invention.

Claims

Claims

1. Bending structure (6) for an insertion tube (2) of a medical device (1), comprising tubular vertebrae (16) with a proximal tubular vertebra (16p) and a distal tubular vertebra (16d) and at least one actuating cable (13) extending in a diametrical bending plane (D) of the structure, the bending structure (6) comprising a tube (15) with a longitudinal axis, cut by cutting lines (T) of an energy beam to produce tubular vertebrae (16) nested in each other by diametrically opposed male cut-out zones (17m, 18m) and diametrically opposed female cut-out zones (17f, 18f) forming rotation pivots along pivot axes (X) located in a plane of symmetry (S), cutting lines being arranged to delimit between the tubular vertebrae (16) notches (20,21) cut into the tube to form flexion zones for the tubular vertebrae in order to obtain the flexion of the flexion structure in the diametrical flexion plane (D) perpendicular to the pivot axes (X), the flexion structure comprising a system (23) for holding the tubular vertebrae together between two opposite extreme positions, the holding system comprising:, - at least one ear (26) extending projecting from the male cut-out areas (17m, 18m) and engaged in a slot (27) of the female cut-out areas (17f, 18f) and having two rotation-limiting surfaces (27a, 27b) located on either side of the plane of symmetry (S), - a pair of hooks (30, 31) extending projecting from the tubular vertebrae, outside the diametrical plane of flexion (D) and according to an orthogonal symmetry with respect to the longitudinal axis (L), each hook having an L shape with a rectilinear finger (36) curved at its end, on one side to present a heel (37) delimiting opposite the end of the finger, a holding surface (37b) having a flat surface, the hooks each being engaged in a housing (32, 33) arranged in a neighboring tubular vertebra and opening in an extreme edge (16b) of said neighboring vertebra by a narrowed part (39) for guiding the rectilinear finger (36) bordered by a holding stop (34) on which the hook by its heel (37) comes to bear in the two extreme positions.

2. Flexural structure according to claim 1 according to which the hooks (30, 31) are arranged from one tubular vertebra to the other alternately on either side of the diametrical plane of flexion (D).

3. Bending structure according to one of the preceding claims, according to which the holding system (23) is arranged so that for each extreme position between two neighboring tubular vertebrae, on the one hand, the two ears (26) of two diametrically opposed male cut-out zones (17m, 18m) are supported on the limiting surfaces (27a, 27b) of the slots located on one side of the plane of symmetry located opposite the direction of bending and on the other hand, the hook (30, 31) located on the side of this plane of symmetry, is supported on the holding stop (34).

4. Bending structure according to one of the preceding claims according to which two ears (26) extend projecting from each of the male cut-out zones (17m, 18m) and each engaged in a slot (27) of the female cut-out zones (17f, 18f) and having a first bearing surface and a second bearing surface (26a, 26b) intended to cooperate with a rotation-limiting surface (27a, 27b).

5. Bending structure according to one of the preceding claims, according to which each lug (26) has at least one bearing surface (26a, 26b) not passing through the pivot axis (X) and intended to cooperate in an extreme position, with a rotation-limiting surface (27a, 27b) extending along a plane not passing through the pivot axis (X), so as to fit into one another.

6. Bending structure according to one of the preceding claims according to which each male cut-out zone (17m, 18m) has a connecting neck (17c) with the part forming a rotation pivot.

7. Flexural structure according to the preceding claim according to which each female cut-out zone (17f, 18f) is arranged to connect with an extreme edge (16a) of the tubular vertebra, using non-pointed reinforcing heels (16t) extending on either side of the part forming a rotation pivot and intended to engage in the connecting neck.

8. Flexing structure according to one of the preceding claims according to which the holding system (23) comprises for at least one tubular vertebra (16), two pairs of tongues (42) arranged symmetrically on either side and outside the diametrical plane of flexion (D) while each being engaged in a groove (43) arranged in a neighboring tubular vertebra.

9. Bending structure according to one of the preceding claims, wherein the tube (15) has a diameter less than or equal to 10 mm.

10. A bending structure according to any preceding claim wherein the tube (15) has a wall thickness of between 0.05 and 1.5 mm.

11. Insertion tube of a medical device (1) of the endoscope or catheter type comprising a bending structure (6) according to one of the preceding claims, fixed at its proximal end to the tube and at its distal end, to a distal head (4).

12. Medical device (1) comprising a control handle (3) equipped at its distal part with an insertion tube (2) according to the preceding claim.

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