Cut-out bending structure for medical device

Description

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 bending 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.

[0005] The medical device of the catheter or endoscope type according to the invention is used for diagnostic, therapeutic or surgical purposes for the inspection of all internal parts of the human body accessible by natural or artificial means. 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 means. Prior art

[0006] 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 portion 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 equipping the handle to ensure the sliding of the cables and consequently, the folding of this bending portion in order to orient the distal head.

[0007] The manufacture of this crutch part requires the assembly of the vertebrae, leading to assembly difficulties 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 through a reduced diameter access route. This miniaturization must take into account the need to mount inside the insertion tube, various devices adapted to allow different functions to be performed such as fluid supply, fluid suction, instrument supply, taking samples or surgical operations, and the passage for the vision system connections.

[0008] US Patent 5,002,041 describes an endoscope whose deflection portion comprises two nested springs to obtain an offset between the turns of the springs in order to provide space for the mounting of a cable which is thus guided in translation. Such a solution leads to a relatively bulky deflection portion which does not allow the cross-section of the endoscope to be reduced without risking altering the operation of the equipment positioned inside the insertion tube.

[0009] Patent application WO 2014 / 061842 describes an endoscope comprising a deflection part formed in particular by a helical spring whose turns are provided with aligned concave deformations to serve as a guide for an actuation cable. The production of these concave deformations on a spring leads to manufacturing difficulties and a high manufacturing cost, in particular for insertion tubes of small diameters.

[0010] In the state of the art, it is also known in particular from documents EP 1 604 607, CN 107951456, CN 104605805, CN 107520273 and EP 3 195 784 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 within each other by cut zones forming rotation pivots along 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.

[0011] Document EP2130478A1 discloses a flexion 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 surrounded by a sheath over at least part of its length, the flexion structure comprising a tube cut by cutting lines to produce tubular vertebrae nested within each other by cut zones forming rotation pivots along pivot axes, 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 at least one flexion plane perpendicular to the pivot axes, the proximal tubular vertebra comprising for an actuating cable,an axial and radial locking system for the sheath comprising an elongated cutout arranged to delimit two stop edges limiting the radial engagement of the sheath inside the cutout.,

[0012] However, there is a difficulty in ensuring the mounting of the actuation cables in a position suitable for providing a bending capacity to the distal head over a wide angular range. Indeed, it should be noted that the actuation cable slides inside a fixed protective sheath during bending operations. It follows that the positioning of the actuation cable must be such that, on the one hand, its sliding movement can cause the bending structure to bend over the entire desired angular range and, on the other hand, friction with the sheath must be limited.

[0013] Additionally, there is a difficulty in assembling such a flexion structure with the insertion tube on one side and the distal head on the other side. Indeed, such an assembly must be safe and efficient while having a limited footprint. Statement of the invention

[0014] The present invention therefore aims to remedy the drawbacks of the state of the art by proposing a bending structure for a medical device of the catheter or endoscope type, having a low manufacturing cost, being able to have a reduced cross-section for its passage in a small diameter access route while offering sufficient bending capacity to the distal head without altering the various devices implemented by this endoscope.

[0015] To achieve such an objective, the flexion structure for an insertion tube of a medical device comprises tubular vertebrae with a proximal tubular vertebra and a distal tubular vertebra and at least one actuating cable surrounded by a sheath over at least part of its length, the flexion structure comprising a tube cut by cutting lines of an energy beam to produce tubular vertebrae nested within each other by cut zones forming rotation pivots along pivot axes, 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 at least one flexion plane perpendicular to the pivot axes, the proximal tubular vertebra comprising for each actuating cable,an axial and radial locking system for the sheath comprising an elongated cutout arranged to delimit two stop edges limiting the radial engagement of the sheath inside the cutout, this cutout opening at its distal part into a slot delimited by at least two cutting lines between which is attached a support tab arranged to radially urge the sheath against the two stop edges of the cutout, this slot being bordered by an axial stop edge of the sheath on which the distal end of the sheath bears.,

[0016] Advantageously, the proximal tubular vertebra comprises, at its proximal part, connecting tabs extending axially and comprising a radial deformation to engage in the distal part of the insertion tube.

[0017] According to one embodiment, the proximal tubular vertebra comprises, between two neighboring tabs, teeth comprising end edges abutting the edge of the distal end of the insertion tube.

[0018] According to an alternative embodiment, the distal tubular vertebra is provided with a system for positioning the actuation cable for welding it to the distal tubular vertebra, this positioning system comprising a support tab cut from the tube by two parallel cutting lines, remaining attached to the tube at its ends by attachment zones and two counter tabs extending on either side of the support tab, each being cut from the tube by two parallel cutting lines, remaining attached to the tube at its ends by attachment zones, the actuation cable being positioned before welding between the counter tabs and the support tab, at least one weld making it possible to fuse the actuation cable to the support tab.

[0019] Advantageously, the distal tubular vertebra is provided with an assembly system with a distal head comprising at least two insertion cutouts for a finger of the distal head, arranged to open at the distal part by an engagement channel for the finger, at least one cutout having two locking points for a finger of the distal head, extending on either side of the engagement channel of this cutout.

[0020] According to a first embodiment, the tube is cut by a first series of cut zones forming rotation pivots and by a second series of cut zones forming rotation pivots extending diametrically opposite to the first series to form first pivot axes, cutting lines being arranged to delimit between the tubular vertebrae, at least a first series of notches to form flexion zones for the tubular vertebrae in order to obtain the flexion of the flexion structure in a direction perpendicular to the first pivot axis.

[0021] According to the invention, the cut-out areas forming rotation pivots cooperate with each other through their thickness.

[0022] According to a preferred embodiment, tubular vertebrae comprise at least one tab cut from the tube by two parallel cutting lines, remaining attached to the tube at its ends by attachment zones, the tab being pushed back inside the tube to constitute a guide eye for the actuating cable.

[0023] Another object of the invention is to provide an insertion tube for a medical device 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.

[0024] Another object of the invention is to provide a control handle for a medical device, equipped at its distal part with an insertion tube according to the invention.

[0025] Various other characteristics emerge from the description given below with reference to the appended drawings which show, by way of non-limiting examples, embodiments of the subject of the invention. Brief description of the drawings

[0026] [ Fig. 1 ] There Figure 1 is a general schematic view of a medical device of the catheter or endoscope type in the general sense equipped with a bending structure in accordance with the invention. Fig. 2 ] There Figure 2 is a side view showing more particularly a preferred example of embodiment of a bending structure according to the invention. Fig. 3 ]There Figure 3 is a side view of the flexural structure according to the invention illustrated in Figure 2 . [ Fig. 4 ]There Figure 4 is a cross-sectional view of the flexural structure according to the invention illustrated in Figure 3 . [ Fig. 5 ]There Figure 5 is a perspective view of the flexural structure according to the invention illustrated in Figure 3 . [ Fig. 6 ]There Figure 6 is a perspective view of the interior of the flexural structure according to the invention illustrated in Figure 5 . [ Fig. 7 ]There Figure 7 is a plan view showing the flexural structure illustrated in Figure 5 , in a bent or crutched position. [ Fig. 8 ]There Figure 8 is a perspective view showing the flexural structure illustrated in Figure 5 , in a bent or crutched position. [ Fig. 9 ]There Figure 9 is a perspective view of another alternative embodiment of the bending structure according to the invention. Fig. 10 ]There Figure 10 is an analogous view of the flexural structure illustrated in Fig. 9 , shown in a 90° offset crutch position. [ Fig. 11 ]There Figure 11 is a plan view showing the distal head and flexure structure before assembly. Fig. 12 ]There Figure 12 is a perspective view showing the assembly of the distal head with the flexure structure. Fig. 13 ]There Figure 13 is a half-sectional view showing the mounting of the actuation cable to facilitate its welding to the distal tubular vertebra. Fig. 13A ]There Figure 13A is a half-sectional view showing an alternative assembly of the actuation cable to facilitate its welding to the distal tubular vertebra. Fig. 14 ]There Figure 14 is a perspective view showing the insertion tube and flexure structure before assembly. Fig. 15 ]There Figure 15 is a perspective view showing the positioning of the actuation cable in the proximal tubular vertebra of the flexion structure. Fig. 16 ]There Figure 16 is an interior side perspective view showing the positioning of the actuation cable in the proximal tubular vertebra of the flexion structure. Fig. 17 ]There Figure 17 is a perspective view showing the insertion tube and flexure structure in the assembled position. Description of the embodiments

[0027] There Figure 1 illustrates by way of example, 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 2 1 connected to a control handle 3 and on the opposite side, a distal part 2 2 , which is equipped with a distal head 4. The insertion tube 2 is fixed temporarily or permanently 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 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.

[0028] According to a preferred embodiment, 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.

[0029] 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.

[0030] 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 is straight ( Figure 2 ) and a crutched position in which the crutching part 6 is curved ( Figures 7, 8 ). 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 driving in rotation 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 level of the distal head 4. Typically, each actuating cable 13 is surrounded by a sheath 13g over at least part of its length.

[0031] According to a preferred embodiment illustrated by the Figures, the bending structure 6 comprises a tube 15 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-out areas 17m, 17f of the first series extend diametrically opposite to the cut-out areas 18m, 18f of the second series to form a first pivot axis 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.

[0032] Advantageously, each series of cut-out areas alternately comprises male cut-out areas 17m, 18m nested in female cut-out areas 17f, 18f respectively. Thus, a tubular vertebra 16 comprises two male cut-out areas 17m, 18m located diametrically opposite each other cooperating with two female cut-out areas 17f, 18f arranged in a manner also diametrically opposite 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.

[0033] It should be understood that the cut-out areas 17m, 17f, 18m, 18f forming rotation pivots cooperate with each other through 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 the Figures 2 à 10 , the male cut-out shapes 17m, 18m are 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.

[0034] 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 material thickness of between 0.05 and 2 mm. The tube 15 has a diameter of between 1 mm and 20 mm, for example.

[0035] Likewise, 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.

[0036] As it emerges from the Figures 2 And 3, the cutting lines T are arranged to form in the tube, a series of tubular vertebrae 16 juxtaposed to 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. Preferably, apart from the distal tubular vertebra 16d and the proximal tubular vertebra 16p, the tubular vertebrae 16 all have the same width taken along the longitudinal axis L. For example, these tubular vertebrae 16 have a width of, for example, between 1 and 25 mm.

[0037] As is evident from the example of realization illustrated on the Figures 2 à 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 relative to each other around the first pivot axis X, along a diametrical flexion plane D 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 the tubular vertebrae 16 in pairs and, on the other side of the plane of symmetry S, the notches 21 of the second series separating the tubular vertebrae 16 in pairs.

[0038] Preferably, the notches 20 of the first series are made according to an identical angular extension range. Similarly, 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 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.

[0039] It is clear from the above description that the notches 20, 21 are made in the tube 15 with a removal of material. Preferably, the notches 20 of the first series are made with a cut that is identical in dimensions and shape. Similarly, the notches 21 of the second series are made with a cut that is identical 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.

[0040] As more precisely shown in the Figure 3 , each notch 20, 21 between two adjacent tubular vertebrae 16 results from a cut made only in the external edge of one tubular vertebra 16. Of course, each notch 20, 21 between two adjacent tubular vertebrae 16 can result from a cut made in the external edge of two neighboring tubular vertebrae 16.

[0041] In the examples of realization illustrated in Figures 2 à 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. Furthermore, in the embodiment illustrated in Figures 2 à 8 , 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.

[0042] According to another embodiment variant, it may be provided to produce a tubular structure 6 adapted to allow flexion in two planes perpendicular to each other using three or four actuating cables 13 in order to obtain left-right and up-down movement of the distal head 4. The Figures 9 et 10 illustrate such an exemplary embodiment for which the tube 15 is cut to comprise a third series of cut zones 17'm, 17'f forming rotation pivots and by a fourth series of cut zones 18'm, 18'f 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 plane of flexion D. Thus, two neighboring tubular vertebrae 16 equipped with the cut zones 17'm, 17'f of the third series and the cut zones 18'm, 18'f of the fourth series are adapted to pivot relatively to each other around a second pivot axis Y passing through a rotation pivot 17'm, 17'f of the third series and through a rotation pivot 18'm, 18'f of the fourth series, this second pivot axis Y being perpendicular with respect to the first axis of X-swivel.

[0043] The cut-out areas 17'm, 17'f of the third series and the cut-out areas 18'm, 18'f of the fourth series can be produced on tubular vertebrae 16 already provided with the cut-out areas 17m, 17f of the first series and the cut-out areas 18m, 18f of the second series or on tubular vertebrae 16 without the cut-out areas 17m, 17f of the first series and the cut-out areas 18m, 18f of the second series, as illustrated by way of example on the Figures 9 et 10 In the latter case, the alternation of the tubular vertebrae 16 between those allowing rotation along the first pivot axis X and those allowing rotation along the second pivot axis Y is chosen to obtain the desired flexion radius.

[0044] Cutting lines are arranged to delimit between the tubular vertebrae 16, a third series of notches 20' and a fourth series of notches 21' cut in the tube extending symmetrically on either side of the diametrical plane of flexion D to form flexion zones for the tubular vertebrae in order to obtain the flexion of the flexion structure in a flexion plane perpendicular to the diametrical plane of flexion D, that is to say in the plane of symmetry S ( Figure 10 ).

[0045] This third series of cut-out areas 17'm, 17'f and the fourth series of cut-out areas 18'm, 18'f have the same characteristics as the cut-out areas 17m, 17f of the first series and the cut-out areas 18m, 18f of the second series. In the example illustrated, the cut-out areas 17'm, 17'f of the third series and the cut-out areas 18'm, 18'f of the fourth series have the same embodiment, but it is clear that the cut-out areas 17'm, 17'f of the third series and the cut-out areas 18'm, 18'f of the fourth series may be made differently from the cut-out areas 17m, 17f of the first series and the cut-out areas 18m, 18f of the second series.

[0046] The cut-out areas of the third and fourth series 17'm, 17'f, 18'm, 18'f forming rotation pivots cooperate with each other by their thickness. Similarly, the cut-out areas of the third and fourth series 17'm, 17'f, 18'm, 18'f forming rotation pivots alternately comprise male cut-out areas 17'm, 18'm nested in female cut-out areas 17'f, 18'f.

[0047] In general, it is clear from the above description that the tube 15 is cut by cutting lines T of an energy beam to produce tubular vertebrae 16 nested within each other by cut zones 17m, 17f, 18m, 18f, 17'm, 17'f, 18'm, 18'f forming rotation pivots along two pivot axes X, Y, perpendicular to each other. Cutting lines are arranged to delimit between the tubular vertebrae 16 notches 20, 21, 20', 21' 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 D, S perpendicular to the pivot axes X, Y.

[0048] The tubular structure 6 thus comprises a series of tubular vertebrae 16 fitted into one another, directly after cutting, without the need for operations of mounting the tubular vertebrae 16 together. The tubular vertebrae 16 are thus assembled together by fitting into one another. The notches 20, 21, 20', 21' form flexion zones in order to obtain the flexion of the flexion structure in at least one diametral plane D, S of flexion perpendicular to the pivot axis X, Y ( Fig. 7 à 10 ). This tubular structure 6 has a reduced cost and can have reduced diameters since it does not require any operation of mounting the tubular vertebrae 16 together.

[0049] According to an advantageous embodiment characteristic, some of the tubular vertebrae 16 comprise at least one tab 25 cut from the tube 15 by two parallel cutting lines 25a, remaining attached to the tube at its ends by attachment zones 25b. Each tab 25 is pushed back inside the tube to constitute a guide eye for the actuating cable 13. For example, each tab 25 thus has, from the attachment zones 25b, a segment curved towards the inside of the tube and connecting together by a concave central part ( Figure 6 ).

[0050] According to an advantageous embodiment characteristic, each tab 25 is produced according to an angular extension range centered on the extension range of the neighboring notches 20, 21, 20', 21'. Thus, the tabs 25 are centered relative to the bending plane. For each actuating cable 13, several tabs 25 are arranged along a generatrix of the tube to ensure translational guidance of the actuating cable. In the example illustrated in Figures 2 à 8 , each actuating cable 13 is guided by three tabs 25. Thus, three tubular vertebrae 16 comprise two tabs 25 arranged symmetrically on either side of the plane of symmetry S while being centered relative to the diametrical plane D. Of course, the tabs 25 can be arranged on a different number of tubular vertebrae 16. Similarly, in the example illustrated, the tubular vertebrae 16 provided with the guide tabs 25 are separated two by two by a tubular vertebra 16 not provided with a guide tab. It is clear that the tabs 25 can be produced on the tubular vertebrae 16 according to a different distribution. It must be understood that a series of tabs 25 is produced along a generatrix of the tube for each of the actuating cables 13 equipping the flexion structure 6.

[0051] According to another advantageous embodiment characteristic, the flexion structure 6 comprises a distal tubular vertebra 4d provided with an assembly system 28 with the distal head 4 comprising at least two insertion cutouts 29 for fingers 4a of the distal head 4. These cutouts 29 are arranged in the distal tubular vertebra 16d, each opening at the distal part of the distal tubular vertebra 16d by an engagement channel 29c. In the example illustrated in Figure 8 , three cutouts 29 are provided delimiting three engagement channels 29c distributed regularly along the circumference of the distal tubular vertebra 16d. Each channel 29c has, from the distal part of the distal tubular vertebra 16d, a frustoconical section which narrows towards the bottom of the channel 29c. The distal head 4 also comprises at least two fingers 4a and in the example illustrated, three fingers 4a extending in projection from a proximal edge 4p of the distal head 4, according to an angular distribution identical to the distribution of the cutouts 29. Each finger 4a is arranged to present in the direction of a rounded end 4e, a frustoconical section complementary to the frustoconical section of the engagement channel 29c and adapted to engage in the channel 29c until the proximal edge 4p of the distal head comes into abutment against the distal end of the distal tubular vertebra 16d ( Figure 12 ). The engagement of the fingers 4a of the distal head 4 in the cutouts 29 of the distal tubular vertebra 4d ensures a radial orientation between the flexion structure 6 and the distal head 4 and a rotational lock between these two parts.

[0052] According to another characteristic of the assembly system 28, at least one cutout 29 and in the example illustrated, a cutout 29 is arranged to have two locking tips 29p for a finger 4a of the distal head, extending on either side of the engagement channel 29c and oriented substantially towards the bottom of the cutout 29. When the finger 4a is engaged inside the engagement channel 29c during a translational movement, the tips 29p penetrate into the edges of the finger 4a ensuring the locking of the distal head 4 relative to the flexion structure 6, in the extraction direction. The cooperation between the tips 29p and the fingers 4a ensures the axial anti-extraction of the distal head relative to the flexion structure 6. The distal head 4 can thus be fixed easily and securely to the flexion structure 6 according to the invention.Furthermore, as explained previously, this distal tubular vertebra 16d provided with the assembly system 28 can be obtained directly after cutting, without the implementation of additional manufacturing steps.

[0053] According to another advantageous embodiment characteristic, the flexion structure 6 comprises a distal tubular vertebra 16d on which is welded one end 13 1 of at least one and in the example illustrated, of two actuating cables 13 as illustrated in Figure 5 . Of course, in the case where the flexion structure 6 is provided with three or four actuating cables 13, the ends of the actuating cables can be welded to the distal tubular vertebra 16d. Conventionally, the actuating cable 13 is made of stainless steel. The welding of the end of the actuating cable 13 can be carried out in any suitable manner such as by the spot welding technique (principle using the principle of resistance welding) or by laser welding. Of course, the ends 13 2 of the actuating cables 13 are fixed to the pulley 12 using any suitable type of fixing.

[0054] According to an advantageous characteristic of embodiment illustrated more precisely in Figures 12 And 13, the flexion structure 6 comprises a distal tubular vertebra 16d provided with a positioning system 30 for the actuation cable 13 to allow its correct welding on the distal tubular vertebra 16d. This positioning system 30 comprises a radial support tab 31 cut from the tube by two parallel cutting lines 32, remaining attached to the tube at its two ends by attachment zones 31a. The support tab 31 is therefore pushed back inside the distal tubular vertebra 16d to allow the positioning of the actuation cable 13 on the external surface of the support tab 31 so that the actuation cable 13 is accessible from the outside of the tube 15.More precisely, the actuating cable 13 is urged to bear on this tab 31 by two counter tabs 33 extending radially on either side of the support tab 31, each being cut from the tube by two parallel cutting lines 34, and remaining attached to the tube at its two ends by attachment zones 33a. These two counter tabs 33 ensure good contact of the actuating cable 13 with the support tab 31, making it possible to ensure effective welding of the actuating cable 13 to the distal tubular vertebra 16d. For example, the . figure 13 shows the production of a weld 13s advantageously by transparency allowing the actuating cable 13 to be fused to the support tab 31 of the tube 15. In addition, as explained previously, this distal tubular vertebra 16d provided with the positioning system 30 can be obtained directly after cutting, without the implementation of additional manufacturing steps.

[0055] There Figure 13A illustrates an alternative variant of positioning the actuation cable 13 to allow its correct welding on the distal tubular vertebra 16d. According to this variant, the actuation cable 13 is supported by the two counter tongues 33 which extend radially on either side of the support tongue 31. The support tongue 31 is pushed inside the distal tubular vertebra to come by its internal surface, in support on the actuation cable 13. The support tongue 31 is thus deformed to correctly position the actuation cable 13 before welding. A transparent weld 13s thus makes it possible to fuse the actuation cable 13 to the support tab 31 of the tube 15. Thus, the actuation cable 13 is positioned before welding between the counter tabs 33 and the support tab 31, and at least one weld 13s makes it possible to fuse the actuation cable 13 to the support tab 31.

[0056] According to the invention illustrated more particularly in Figures 14 à 16 , the proximal tubular vertebra 16p comprises, for each actuation cable 13, an axial and radial locking system 40 for the sheath 13g surrounding each actuation cable 13. This axial and radial locking system 40 comprises a cutout 41 arranged axially in the proximal tubular vertebra 16p, parallel to its longitudinal axis. This cutout 41 is of elongated shape and is delimited by two so-called stop edges 41a extending parallel to each other and to the longitudinal axis of the proximal tubular vertebra 16p. The width of this cutout between its stop edges 41a is determined to allow partial engagement of the sheath 13g inside the cutout 41. In other words, this cutout 41 is arranged to delimit two stop edges 41a limiting the radial engagement of the sheath 13g inside the cutout. As more precisely shown in the Figures 14 And15 , the sheath 13g is in contact with the stop edges 41a along two of its generatrices, considering that the part of the sheath located between these two generatrices is inserted inside the cutout 41. For example, when the sheath 13g is in abutment against the stop edges 41a, the sheath 13g by its outermost generatrix is ​​substantially tangent to the outer surface of the proximal tubular vertebra 16p. It should be noted that such an arrangement frees up space inside the flexion structure 6.

[0057] This cutout 41 opens at its distal part, into a lumen 43 delimited by at least two cutting lines 43a arranged radially in the proximal tubular vertebra 16p to delimit between them, a support tab 44 attached to the proximal tubular vertebra 16p, by its ends using attachment zones 44a. This support tab 44 is pushed back inside the proximal tubular vertebra 16p to allow the positioning of the sheath 13g of the actuating cable on the external surface of the support tab 44, between the support tab 44 and the body of the proximal tubular vertebra 16p. Thus, the support tab 44 is arranged to radially urge the sheath 13g to bear against the two stop edges 41a of the cutout 41.

[0058] According to the invention, this lumen 43 is bordered by an axial stop edge 45a for the sheath 13g of the actuation cable 13. The sheath 13g has a distal end 13d intended to bear on the axial stop edge 45a. It should be understood that beyond this distal end 13d of the sheath 13g, the actuation cable 13 is devoid of the sheath 13g. Advantageously, the axial stop edge 45a is produced by the radial edge of a notch 45 arranged axially in the proximal tubular vertebra 16p, opening on the proximal side, into the lumen 43. This notch 45 is delimited by two bearing edges 45b extending parallel to each other and to the longitudinal axis of the proximal tubular vertebra 16p. These two support edges 45b are connected to each other on the distal side, by the axial stop edge 45a.This notch 45 is arranged to allow partial engagement of the sheath 13g inside the notch 45 and the positioning of the distal end 13d of the sheath 13g against the axial stop rim 45a. The sheath 13g is thus in abutment by substantially half of its distal end 13d against the axial stop rim 45a.

[0059] According to an advantageous implementation characteristic, it should be noted that when the sheath 13g is in abutment against the axial stop edge 45a, it is possible to weld the sheath 13g to the proximal tubular vertebra 16p so as to block the sheath 13g in translation. For this purpose, a weld is made for example between the distal end 13d of the sheath 13g on the one hand and the axial stop edge 45a and / or the bearing edges 45b and / or the stop edges 41a of the proximal tubular vertebra 16p on the other hand.

[0060] It should be noted that the support tab 44 also radially urges the sheath 13g to come into contact against the two support edges 45b, ensuring the positioning of the distal end 13d of the sheath 13g against the axial stop edge 45a. Typically, the notch 45 and the cutout 41 are arranged in the extension of one another. For example, when the sheath 13g is in abutment against the support edges 45b, the sheath 13g by its outermost generatrix is ​​substantially tangent to the outer surface of the proximal tubular vertebra 16p.

[0061] It should be noted that the axial stop edge 45a may not be delimited by the notch 45 as illustrated in the drawings but by the distal cut edge delimiting the lumen 43. Preferably, the proximal tubular vertebra 16p is provided between the axial and radial locking system 40 and its distal end, with a tab 25 arranged to ensure the translational guidance of the actuating cable 13.

[0062] It is clear from the above description that such an axial and radial locking system 40 makes it possible to ensure correct positioning of the actuating cable 13, limiting friction inside the sheath 13g. The locking system 40 makes it possible to position, without curvature, the actuating cable 13 so that it is aligned with its part which is guided in translation by the tabs 25. This locking system 40 also contributes to the radial mechanical strength between the insertion tube 2 and the bending structure 6. Furthermore, the axial locking of the sheath 13g against the axial stop edge 45a constitutes a robust stop making it possible to transmit significant forces into the actuating cable.

[0063] According to an advantageous embodiment characteristic, the proximal tubular vertebra 16p comprises, at its proximal part, connecting tabs 48 extending axially and having radial flexibility to engage in the distal part of the insertion tube 2 and ensure assembly between the insertion tube 2 and the flexion structure 6. The tabs 48 are distributed over the circumference of the proximal tubular vertebra 16p in a regular or irregular manner. For example, the proximal tubular vertebra 16p comprises two pairs of two tabs 48 arranged in a diametrically opposite manner. It should be noted that the two tabs 48 of a pair are spaced apart so as to allow the positioning between them and the guidance of an actuating cable 13 as illustrated in Figure 16 .

[0064] Each tab 48 has a radial deformation 48a produced for example by folds, so that the tab extends substantially parallel to the longitudinal axis of the proximal tubular vertebra 16p but being offset towards the inside of the proximal tubular vertebra. The radial offset of the tabs 48 allows the engagement of the tabs in the distal part of the insertion tube 2 having a diameter substantially identical to the diameter of the proximal tubular vertebra 16p. As is more precisely shown in the Figure 17 , the proximal tubular vertebra 16p and the insertion tube 2 are thus flush in the assembled position. It should be noted that the assembly by tabs offers the advantage of presenting a limited size while avoiding the addition of an additional connecting piece adding thickness.

[0065] Preferably, the tabs 48 are arranged so as to leave teeth 49 between two neighboring tabs. The teeth 49 are detached from the teeth 49 by cutouts 50 contributing to the flexibility of the tabs 48. In the example illustrated, the proximal tubular vertebra 16p comprises two teeth 49 extending diametrically opposite and on either side of which are located the pairs of tabs 48. The teeth 49 extend axially from the proximal tubular vertebra 16p set back from the end of the tabs 48, and having end edges 49a delimiting together the proximal edge of the proximal tubular vertebra 16p. The tabs 48 can thus be engaged inside the insertion tube 2 until the end edges 49a of the teeth abut on the edge of the distal end of the insertion tube 2 ( Figure 17 ).

[0066] It is clear from the foregoing description that the subject of the invention relates to an insertion tube 2 of a medical device 1 comprising a flexion structure 6 fixed at its proximal end to the insertion tube 2 and at its distal end, to the distal head 4. Advantageously, the distal head 4 is assembled to the flexion structure 6 by the assembly system 28 of the spike anchoring type while the insertion tube 2 is assembled to the flexion structure using the connecting tabs 48. As explained previously, the proximal 16p and distal 16d tubular vertebrae as described above can be obtained directly from the cutting, without the implementation of additional manufacturing steps.

[0067] The invention is not limited to the examples described and shown, the invention being limited only by the subject matter of the appended claims.

Claims

1. A flexing 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) surrounded by a sheath (13g) over at least part of its length, the flexing structure (6) comprising a tube (15) cut with energy-beam cutting lines (T) to create tubular vertebrae (16) that nest in one another via cut-out areas (17m, 17f, 18m, 18f, 17'm, 17'f, 18'm, 18'f) forming pivots for rotation around pivot axes (X, Y), cutting lines being created to delimit, between the tubular vertebrae (16), notches (20, 21, 20', 21') cut in the tube in order to form flexing zones for the tubular vertebrae in order to obtain the flexing of the flexing structure in at least one flexing plane (D, S) perpendicular to the pivot axes (X, Y), the proximal tubular vertebra (16p) comprising, for each actuating cable, a radial and axial blocking system (40) for the sheath, comprising an elongate cutout (41) created in such a way as to delimit two stop edges (41a) that limit the radial engagement of the sheath in the cutout, this cutout opening at its distal part into a slot (43) delimited by at least two cutout lines between which there is attached a pressing tab (44) designed to press the sheath radially against the two stop edges of the cutout, this slot (43) being bordered by a rim (45a) for axially stopping the sheath, on which the distal end (13d) of the sheath is pressed.

2. Flexing structure according to the preceding claim, wherein the proximal tubular vertebra (16p) comprises, at its proximal part, connection tabs (48) extending axially and comprising a radial deformation (48a) for engaging in the distal part of the insertion tube (2).

3. Flexing structure according to the preceding claim, wherein the proximal tubular vertebra (16p) comprises two neighbouring tabs (48), teeth (49) comprising end edges (49a) abutting on the distal end edge of the insertion tube (2).

4. Flexing structure according to one of the preceding claims, wherein the distal tubular vertebra (16d) is provided with a positioning system (30) of the actuating cable (13) for its welding on the distal tubular vertebra (16d), this positioning system comprising a pressing tab (31) cut from the tube by two parallel cutout lines, while remaining attached to the tube at its ends by attachment zones and two counter tabs (33) extending on either side of the pressing tab each being cut from the tube by two parallel cutout lines, while remaining attached to the tube at its ends by attachment zones, the actuating cable (13) being positioned before welding between the counter tabs (33) and the pressing tab (31), at least one weld (13s) enabling fusing of the actuating cable (13) to the pressing tab (31).

5. Flexing structure according to one of the preceding claims, wherein the distal tubular vertebra (16d) is provided with an assembly system (28) with a distal head comprising at least two insertion cutouts for a finger (4a) of the distal head (4), created opening at the distal part by an engagement channel (29c) for the finger, at least one cutout having two blocking points (29p) for a finger of the distal head, extending on either side of the engagement channel of this cutout.

6. Flexing structure according to one of the preceding claims, wherein the tube (15) is cut by a first series of cut-out areas (17m, 17f) forming rotation pivots and by a second series of cut-out areas (18m, 18f) forming rotation pivots extending diametrically opposite with respect to the first series in order to form first pivot axes (X), cutting lines being created to delimit, between the tubular vertebrae (16), at least one first series of notches (20) to form flexing zones for the tubular vertebrae in order to obtain the flexing of the flexing structure in one sense of the direction perpendicular to the first pivot axis (X).

7. Flexing structure according to the preceding claim, wherein the cut-out areas (17m, 17f, 18m, 18f, 17'm, 17'f, 18'm, 18'f) forming rotation pivots cooperate with one another via their thickness.

8. Flexing structure according to one of the preceding claims, wherein the tubular vertebrae (16) comprise at least one tab (25) cut from the tube by two parallel cutout lines (25a), while remaining attached to the tube at its ends by attachment zones (25b), the tab (25) being pushed back inside the tube (15) in order to constitute a guide eye for the actuating cable (13).

9. A set comprising an insertion tube (2) of a medical device (1) of the endoscope or catheter type and comprising a flexing structure (6) according to one of the preceding claims, the flexing structure (6) being fixed at its proximal end to the insertion tube and at its distal end to a distal head (4).

10. Medical device (1) comprising a control handle (3) equipped at its distal part with a set according to the preceding claim.