ENDOSCOPIC SYSTEM COMPRISING A FLEXIBLE INSERTION TUBE AND A BENDING PORTION - Patent application

Abstract

To provide an endoscope containing a flexible insertion tube and a bend, in which the bend and the insertion tube provide a sufficient space inside.SOLUTION: An endoscope (1) contains a flexible insertion tube (2), and a bend (3) controllable from the proximal side, and connected to the insertion tube (2) in the distal direction. In the bend (3), a pull rope (11) extends for pivotal movement of the bend (3), and the pull rope (11) is fixed to the distal end of the bend (3), and an energized elastic element (30) is arranged in the longer direction of the bend (3) in parallel with the pull rope (11).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an endoscope comprising a flexible insertion tube and a proximally controllable bending section, the bending section being distally connected to the insertion tube. [Background technology]

[0002] This type of endoscope can be constructed with a very small diameter, for example, to inspect even small openings or spaces.

[0003] Typically, the diameter of the curved portion is equal to or slightly different from the diameter of the insertion tube of the endoscope. For endoscopes with narrow insertion tubes, the curved portion is correspondingly narrow.

[0004] However, thin curved sections often do not have enough interior space for the complex structural design required for conventional curved sections. The curved section of the endoscope may be controlled by the user. To this end, the curved section is controlled, i.e., deflected, by the user from the proximal side of the endoscope.

[0005] Thus, from the prior art, different basic designs of curved sections are known, such as curved sections of articulating members made from metal or curved sections made from articulating plastic elements.

[0006] In the curved section of the metallic articulation member, the curved section is composed of a number of complex shaped metal rings connected to each other by freely movable connections of annular joints. The annular joints include hinge pins offset by 90 degrees or 180 degrees respectively with respect to each adjacent annular joint. The curved section can pivot up and down through several pivot points. The annular joints on the inside of the flexible section are arranged with a number of rows of eyelets. The eyelets act as guideways for a pull rope fixed to the distal end of the flexible section. The bending or deflection movement of the flexible section is achieved by pulling the pull rope from the proximal side.

[0007] Basically, two pull ropes are always needed to move in one direction (e.g. upwards / downwards), because only a pulling movement can be achieved with one pull rope, not a thrust movement. So traditionally, two pull ropes were needed for one-way movement. Correspondingly, four pull ropes are needed for two-way movement. The two-way movement allows various orientations (combinations of horizontal and vertical curvatures) to be achieved.

[0008] The complex structure requires adequate interior space inside the curved section. If the curved section is very thin, there is usually not enough interior space available.

[0009] In curved sections made of plastic elements articulated to one another, i.e. hinged to one another, the plastic elements produced by injection molding are interconnected via hinges and can pivot relative to one another. Curved sections of articulated plastic elements show a very simple structure, but offer even less internal space than curved sections of articulated members made from metal. This is due to the fact that the partitions of the plastic members require a certain thickness to ensure sufficient stability and strength. Moreover, the eyelets also require a lot of space in this case. Summary of the Invention [Problem to be solved by the invention]

[0010] It is therefore an object of the present invention to provide an endoscope that includes a flexible insertion tube and a curved portion, the curved portion and the insertion tube providing sufficient space therein. Furthermore, the curved portion of the endoscope is intended to provide satisfactory functionality. [Means for solving the problem]

[0011] This object is achieved by an endoscope comprising the features of claim 1. Advantageous developments are the subject matter of the dependent claims.

[0012] The present invention relates to an endoscope including a flexible insertion tube and a proximally controllable curved section, which is distally connected to the insertion tube. A pull rope for pivoting movement of the curved section extends within the curved section, the pull rope being fixed to the distal end of the curved section. In the longitudinal direction of the curved section, a biased elastic element is arranged parallel to the pull rope. The biased elastic element also occupies space, but it is smaller than the space required by the conventional design with the pull rope and eyelets.

[0013] In this endoscope, at least one pull rope can be replaced by a biased elastic element. The desired deflection of the curved section can be controlled such that only at least one (remaining) pull rope is actuated (pulled). Since at least one pull rope has been replaced by a biased elastic element, the space of the replaced pull rope can be used for other purposes. Since there is no space for the replaced pull rope, the endoscope can have a slimmer design.

[0014] The biased resilient element can include a predetermined curvature toward one side of the curved portion. The predetermined curvature of the biased resilient element imparts the predetermined curvature to the curved portion in an unactuated state. When the pull rope is pulled in an unactuated state, the curvature of the curved portion changes. When the pull rope is pulled in an unactuated state, the curved portion can be removed from the predetermined curvature.

[0015] A predetermined curvature of the biased elastic element can provide a maximum pivoting motion of the curved portion to one side. By pulling on the (at least one) pull rope, the curved portion can be returned from the maximum pivoting motion forced to one side to a smaller pivoting motion. Continued pulling on the pull rope can cause the curved portion to pivot in a straight line. Further pulling on the pull rope causes the curved portion to deflect in a direction opposite to the original pivoting direction imparted in the unactuated state.

[0016] The biased elastic element may be arranged parallel to the pull rope as a curved bar element having a predetermined curvature toward one side of the curved portion, and the pull rope may be guided by a pull rope guide element. In this endoscope, at least one pull rope may be replaced with a curved bar element. The curved bar element may be bendable.

[0017] The biased resilient element can be arranged parallel to the pull rope as a spiral spring element or as a combination of a distal guided pull rope and a proximal spiral spring element, the spiral spring element having a predetermined bias and the pull rope can be guided by the pull rope guide element. In this endoscope, at least one pull rope can be replaced with a spiral spring element or a combination of a distal guided pull rope and a proximal spiral spring element.

[0018] The curved portion may comprise a sleeve. The biased elastic element may be a bendable separating element dividing a cross section of the sleeve into two separate chambers, in one of the two chambers separated by the separating element, a pull rope may be arranged in the longitudinal direction of the sleeve for pivotal movement of the curved portion.

[0019] In this endoscope, at least one pull rope can be replaced by a bendable separation element. Furthermore, by providing a separation element, a separation of the sleeve into two chambers is realized, which serve to guide the pull rope. The separation element replaces the conventional guidance through the eyelet.

[0020] The curved section can be easily divided by the separating element into longitudinally extending and radially delimited pull rope ducts. This allows an endoscope with a curved section to be provided simply and inexpensively. The simple design allows particularly small construction sizes, since the principle of dividing the curved section into separate chambers by the separating element can be applied to any construction size, in particular to very small endoscope diameters.

[0021] At least one pull rope is disposed in one chamber. In this minimal configuration, the curved portion can be specifically pivoted by pulling one pull rope.

[0022] The separation element can have a predetermined curvature towards one side of the curved portion. The predetermined curvature of the separation element curved in a predetermined manner can provide a maximum pivoting movement to one side of the curved portion.

[0023] In one of the two chambers separated by a separating element arranged outside the radius of the separating element curved in a predetermined manner, the pull rope can be arranged in the longitudinal direction of the sleeve for pivotal movement of the curved portion.

[0024] In this manner, by pulling the pull rope, the curved portion that has been curved in a predetermined manner can be bent in a direction that straightens the curved portion. The pull rope can be pulled until the curved portion is aligned so as to be straight. The pull rope can also be pulled further so that the curved portion is curved in a direction opposite to the initial bending direction.

[0025] The separation element can be fixed at its proximal side to the distal end region of the insertion tube such that its length protruding towards the distal side is predefined, and thus the fixing can be achieved in a safe and secure manner, but also in a simple and low-effort manner.

[0026] The insertion tube can include an outer cover and a resilient wire mesh beneath the outer cover, with the proximal side of the separation element secured to a distal end region of the wire mesh. The wire mesh incorporated into the insertion tube provides rigid support to the proximal side of the separation element.

[0027] The proximal side of the separation element may be inserted into the distal end region of the wire mesh or may be welded or glued to the distal end region of the wire mesh.

[0028] The outer diameter of the curved sleeve may be 3 mm or less. In even smaller designs, the curved sleeve can even have an outer diameter of 1 mm or less. The endoscope is therefore suitable for particularly small cavities that could not be examined before with a flexible endoscope with a curved section.

[0029] The separating element can be made of spring steel, stainless steel, or a flexible plastic material. The material of the separating element imparts curvature to the curved portion. However, the separating element is neither compressible nor expandable. In this way, the length of the curved portion, which corresponds to the length of the separating element, remains the same when the curved portion is curved.

[0030] The sleeve of the curved portion can include a spring element. In this way, both flexibility and the necessary stiffness can be imparted to the sleeve and thus to the curved portion. Furthermore, the curved portion can be configured to be anti-kinking (torsion resistant).

[0031] The spring element can be embedded in the sleeve of the curved portion. The material of the sleeve can be plastic or rubber. The sleeve with the spring element is therefore easy to manufacture. For example, the material of the sleeve can be injection molded or extruded around the spring element.

[0032] The cross-section of the separation element may be configured such that the cross-section of the separation element is wider in a first direction and narrower in a second direction perpendicular to the first direction. The cross-section of the separation element may have a rectangular, oval, elliptical, or racetrack shape (so-called stadium shape). The separation element may be curved in the direction of the narrow side of the cross-section. The separation element may not be curved in the direction of the wider side of the cross-section.

[0033] In the chamber located on the outside of the curved separating element, one single pull rope may be arranged for the pivoting movement of the curved part, and in the other chamber located on the inside of the curved separating element, no pull rope is arranged. This design allows the diameter to be further reduced, since only one pull rope requires installation space.

[0034] The chamber arranged on the outside of the curved separating element may have multiple pull ropes arranged for pivoting the curved part, and the other chamber arranged on the inside of the curved separating element may not have pull ropes arranged. This design allows the pivoting of the curved part to be performed safely.

[0035] The endoscope may be a flexible endoscope.

[0036] Thus, according to the invention, bending in one direction (forward / backward or left / right) is ensured by only one pull rope and one additional element and bending unit. In a further development, the invention provides bending in all directions (forward and backward as well as right and left and correspondingly all intermediate stages by combined tension) by two pull ropes and two additional elements. The additional elements in this case are understood to be, for example, spring elements or spring bars.

[0037] The above-mentioned aspects of the present invention can be combined as appropriate. [Brief description of the drawings]

[0038] [Figure 1] 1 is a schematic side view of a distal region of an endoscope according to the present invention; [Diagram 2] FIG. 4 is a schematic side view of the inside of a curved portion in the first embodiment. [Figure 3A] FIG. 13 is another schematic side view of the interior of the curved portion of the first embodiment. [Figure 3B] 3B is a schematic cross-sectional view of a curved portion of the first embodiment taken along the cross section III-III in FIG. 3A. FIG. [Figure 4A] FIG. 2 shows how the flexible plate of the first embodiment is inserted into the insertion tube. [Figure 4B] FIG. 2 is a schematic top view on a flexible plate of the first embodiment. [Figure 4C] FIG. 2 is a schematic perspective view of the flexible plate of the first embodiment inserted into the insertion tube. [Figure 4D] FIG. 2 is a schematic side view of the flexible plate of the first embodiment. [Diagram 5] FIG. 11 is a schematic side view of a sleeve of a curved portion in the second embodiment. [Figure 6] FIG. 13 is a schematic perspective view of a spring element according to a second embodiment; [Figure 7] FIG. 6 is a schematic cross-sectional view of a sleeve according to a second embodiment. [Figure 8] FIG. 13 is a schematic side view of the inside of a curved portion in the third embodiment. [Figure 9] FIG. 13 is a schematic side view of the inside of a curved portion in the fourth embodiment. [Figure 10] FIG. 13 is a schematic side view of the inside of a curved portion in the fifth embodiment. [Figure 11] FIG. 13 is a schematic side view of the inside of a curved portion in the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The invention will now be described in detail on the basis of embodiments with reference to the drawings, in which the representations are not necessarily to scale but may be shown distorted for greater clarity.

[0040] First embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4D.

[0041] An endoscope 1 according to the invention comprises an insertion tube 2, a curved section 3 and a distal end 4, distal to a control member (not shown).

[0042] 1 shows a schematic side view of the distal region of an endoscope 1 according to the invention. Distal to the insertion tube 2 a curved section 3 is arranged. Distal to the curved section 3 a distal tip 4 is arranged.

[0043] Insertion tube 2 The insertion tube 2 is flexible and is intended to be inserted with the distal end 4 first into a patient for testing purposes. The insertion tube 2 is bendable to follow the curved opening of the body into which it is inserted. The insertion tube 2 is also sufficiently rigid and torsion-resistant so that it can be pushed over the curved portion of the body opening. The insertion tube 2 includes a cover 21 on the outside and preferably a wire mesh 22 on the inside of the cover 21. The cover 21 protects the inside of the insertion tube 2. The wire mesh 22 gives the insertion tube 2 the necessary flexibility, rigidity and torsion resistance.

[0044] Curved section 3 The curved portion 3 is located at the distal end of the insertion tube 2. The longitudinal direction of the curved portion 3 corresponds to the extension direction of the endoscope 1. The curved portion 3 is pivotable relative to the insertion tube 2. A pull rope 11 is used to pivot the curved portion 3. The pull rope 11 is actuated by being pulled from the proximal side. In an initial position where the pull rope 11 is not pulled, the curved portion 3 is curved as illustrated in FIGS. 1 to 3.

[0045] In the curved portion 3, an elastic sleeve 10 extends from the distal end of the insertion tube 2 to the distal end 4. The elastic sleeve 10 should be considered to be a distal continuation of the cover 21 of the insertion tube 2.

[0046] Separation element 30 In the curved portion 3, a flat flexible plate 30, which is a bendable plate, is arranged as a separation element 30. FIG. 4B shows an example of the flexible plate 30. In the top view, the flexible plate 30 has the shape of an elongated rectangle. The cross section of the flexible plate 30 is formed in a rectangular shape. Thus, the cross section of the flexible plate 30 has a short side and a long side. In the top view of FIG. 4B, the flexible plate 30 is bendable toward the observer and away from the observer. As can be seen from FIG. 4C, in the unloaded initial stage, the flexible plate 30 is bent. The flexible plate 30 is bent so that the short side of the cross section of the flexible plate 30 extends in the radial direction, i.e. along the extension of the radius of curvature. Thus, in the unloaded initial position, the flexible plate 30 is bent to the side (see FIG. 4D). Note that the "unloaded initial position" here means a state in which no force is applied to the flexible plate 30 and the pull rope is not pulled.

[0047] Flexible plate 30 has, viewed longitudinally, a narrower proximal portion 36 and a wider distal portion 35. Proximal portion 36 has a shorter width than distal portion 35.

[0048] The proximal portion 36 is inserted distally into the wire mesh 22 of the insertion tube 2. When inserting the flexible plate 30 into the wire mesh 22, the wider distal portion 35 can be used as a stopper against which the flexible plate 30 is inserted into the wire mesh 22. The length of the flexible plate 30 protruding from the wire mesh 22 is thus predefined.

[0049] The proximal portion 36 may also be welded, glued, or otherwise secured to the wire mesh 22 such that a distal portion 35 of the flexible plate 30 protrudes distally from the wire mesh 22 of the insertion tube 2.

[0050] The sleeve 10 is pulled over the flexible plate 30. Thus, the outer edge of the distal portion 35 presses against the elastic inner circumferential surface of the sleeve 10, thereby dividing the interior of the sleeve 10 in cross section into a first chamber 31 and a second chamber 32. In other words, the flexible plate 30 divides the interior of the sleeve 10. Each of the first chamber 31 and the second chamber 32 is bounded circumferentially by the inner circumferential surface of the sleeve 10 and the flexible plate 30.

[0051] The first chamber 31 and the second chamber 32 extend longitudinally of the sleeve 10 from the distal end of the insertion tube 2 to the distal end 4. In an embodiment, the distal end of the flexible plate 30 is spaced from the proximal face of the distal end 4 (see FIG. 2). Alternatively, the distal end of the flexible plate 30 may abut the proximal face of the distal end 4 or may be fixed to the distal end 4.

[0052] This results in a first chamber 31 and a second chamber 32 separated by the flexible plate 30. Preferably, the first chamber 31 and the second chamber 32 have the same cross-sectional size. The flexible plate 30 therefore divides the interior of the sleeve 10 into two equal halves. Alternatively, the flexible plate 30 can divide the interior of the sleeve 10 into two halves of different size, in which case the first chamber 31 and the second chamber 32 have different cross-sectional sizes.

[0053] 3B, in the first chamber 31, the pull rope 11, the camera cable 12, and the light conductor 13 are arranged to extend in the longitudinal direction of the curved portion 3 parallel to the bending axis of the curved portion 3. In the second chamber 32, the camera cable 12 and the light conductor 13 are arranged to extend in the longitudinal direction of the curved portion 3 parallel to the bending axis of the curved portion 3. No pull rope is arranged in the second chamber 32.

[0054] The flexible plate 30 is bendable and can be made from spring steel, stainless steel, or a bendable plastic material. Despite its flexibility, the flexible plate 30 is neither compressible nor expandable. Thus, the flexible plate 30 has a function similar to that of the spine.

[0055] By pulling the pull rope 11 in the proximal direction, the curved portion 3, which is curved in an unloaded state, is curved in a direction to straighten itself. In other words, when the pull rope 11 is pulled in the proximal direction, the curved portion 3 is elongated.

[0056] Distal end 4 The distal end 4 can function as an endoscope head. A pull rope 11 is fixed to the distal end 4. An optical system (not shown) and a camera (not shown) are arranged on the distal side of the distal end 4. The optical system is connected to a light conductor 13 and ensures illumination of the scene to be viewed. The camera is connected to a camera cable 12 and takes pictures of the illuminated scene.

[0057] The sleeve 10 may abut the distal end 4 or may cover the outer periphery of the distal end 4 .

[0058] The endoscope 1 according to the present invention may be very small. The outer diameter of the insertion tube 2, the sleeve 10 of the curved portion 3 and the distal end 4 may be 3 mm or less. In even smaller designs, the outer diameter of the insertion tube 2, the sleeve 10 of the curved portion 3 and the distal end 4 may be 2 or 1 mm or less.

[0059] Features of the Invention Pulling the pull rope 11 in the proximal direction reduces the distance between the distal end of the insertion tube 2 and the distal end 4. The flexible plate 30 flexes toward the side where the first chamber 31 is located when the single pull rope 11 located in the first chamber 31 is pulled. Thus, the curved portion 3 pivots (to the left in FIG. 3A ) toward the side where the curved portion 3 assumes a straight, or expanded, shape. Pulling the pull rope 11 allows the curved portion 3 to eventually assume a completely straight shape. If the curved portion 3 is in a completely straight shape and the pull rope 11 continues to be pulled proximally, the curved portion 3 will bend in the opposite direction (to the left in FIG. 3A ) from its initial bending direction.

[0060] Effect of the Invention The curved portion 3 exhibits a very simple design, uses few parts and can therefore be manufactured at very low cost.

[0061] The curved section 3 does not require eyelets or other pull rope guide elements as rope guides. This is particularly advantageous for narrow insertion tubes, since no cavity needs to be available for the eyelets. The flexible plate 30 divides the interior of the curved section 3 into two chambers 31, 32. The chamber 31 serves as a rope guide for the pull rope 11. This ensures that the pull rope 11 is safely guided.

[0062] The curved section 3 can obtain any desired curved position by pulling one of the pull ropes 11. Nevertheless, for this purpose only a single pull rope 11 is necessary. Thus, the space required for an additional pull rope is saved. The curved section 3, and thus the entire endoscope, can thus be constructed with a smaller diameter.

[0063] The curved section 3 according to the invention can therefore be used in endoscopes that include very small insertion tubes.

[0064] Second embodiment Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

[0065] In the second embodiment, a spring element 18 for anti-twist protection is arranged on the sleeve 10 of the first embodiment.

[0066] Otherwise, the structure of the second embodiment is similar to that of the first embodiment.

[0067] 5 shows a schematic side view of the sleeve 10 of the curved portion 3 of the second embodiment. For clarity, the pull rope 11 and the bendable plate 30 are not shown, nor are the camera cable 12 and the light conductor 13.

[0068] To impart advantageous curvature to the sleeve 10, a spring element 18, shown in Figure 6, is embedded within the sleeve 10. In Figure 7, the location of the spring element 18 is shown in cross section through the sleeve 10 of the second embodiment.

[0069] The sleeve 10 of the second embodiment can be manufactured such that a plastic material is cast or extruded onto the spring element 18 such that the spring element 18 is sandwiched between the inner and outer circumferential surfaces of the sleeve 10 which are made of a plastic material.

[0070] Thus, the sleeve 10 of the second embodiment may be configured to be bendable, yet also stiff and torsion resistant.

[0071] Moreover, the same effects as those of the first embodiment are achieved.

[0072] Third embodiment A third embodiment of the present invention will now be described with reference to FIG.

[0073] FIG. 8 is a schematic side view of the inside of a curved portion in the third embodiment.

[0074] The curved portion of the third embodiment can utilize the cover 21 of the first or second embodiment. The same applies to the following embodiments.

[0075] Furthermore, the curved portion of the third embodiment utilizes a known joint structure and includes a joint ring 301. A plurality of the multi-joint rings 301 are arranged along the longitudinal direction of the curved portion. Adjacent joint rings 301 are connected to each other by joints 304 so that they can pivot relative to each other around the axis of the joints 304. Thus, each pair of adjacent joint rings 301 has two joints 304 arranged 180 degrees apart from each other, i.e., diagonally on the joint rings 301. The first joint ring 301 at the proximal end of the curved portion includes two joints 304 only on the distal side. The last joint ring 301 at the distal end of the curved portion includes two joints 304 only on the proximal side. The radial outside of the joint structure consisting of the multi-joint rings 301 is covered by a cover (not shown).

[0076] Each articulation ring 301 has a right eyelet 302 and a left eyelet 302 around its periphery. More precisely, each eyelet 302 is formed on the inner circumferential surface of each articulation ring 301. Each eyelet 302 forms an opening extending in the longitudinal direction of the curved portion. Said opening can receive a pull rope, as described below, or a pre-curved spring bar, as described below. The eyelets 302 are shown only diagrammatically in FIG. 8.

[0077] The right eyelets 302 are located opposite to the left eyelets 302. In other words, the positions of the right eyelets 302 on the articulation ring 301 are spaced 180 degrees from the left eyelets 302, i.e., they are located at diagonal positions on the articulation ring 301. When viewed in the longitudinal direction of the curved portion, the left eyelets 302 are all in a row. Similarly, when viewed in the longitudinal direction of the curved portion, the right eyelets 302 are all in a row.

[0078] In FIG. 8, the left eyelet 302 is disposed on the left side of the articulated ring 301 , and the right eyelet 302 is disposed on the right side of the articulated ring 301 .

[0079] In this third embodiment, the pull rope 11 is guided in the left eyelet 302 of the articulated ring 301. In this third embodiment, a pre-curved spring bar 330 is guided in the right eyelet 302 of the articulated ring 301. The distal end of the pull rope 11 is fixed to the last articulated ring 301 at the distal end of the curved section. The distal end of the pre-curved spring bar 330 is fixed to the last articulated ring 301 at the distal end of the curved section. The spring bar 330 constitutes an additional element that is used in addition to the pull rope in the curved section.

[0080] The pre-curved spring bar 330 is a spring wire.

[0081] The pre-curved spring bar 330 is pre-curved towards the curved side, i.e., towards the right in Fig. 8. In this embodiment, the pre-curved spring bar 330 is pre-curved by, for example, about 90 degrees, however, the pre-curved angle can be selected as desired.

[0082] The pre-curvature of the pre-curved spring bar 330 imparts a preset curvature to the side, i.e., to the right in Fig. 8, in the non-actuated state of this third embodiment, in which the right sides of the articulated rings 301 may abut or have a minimum distance from each other, and the left sides of the articulated rings 301 are maximally spaced apart from each other.

[0083] The pre-curved spring bar 330 has a length such that in the aforementioned non-actuated state it protrudes in the proximal direction on the first articulation ring 301 at the proximal end of the curved portion, as shown in Fig. 8. The portion of the pre-curved spring bar 330 that protrudes proximally on the first articulation ring 301 in the non-actuated state has a straight extension (see Fig. 8). The pre-curved spring bar 330 is disposed in the right eyelet 302 of the articulation ring 301 such that the pre-curved spring bar 330 is slidable relative to the right eyelet 302 of the articulation ring 301.

[0084] The pull rope 11 is guided in the left eyelet 302 or in the articulation ring 301. Starting from the non-actuated state of FIG. 8, when the pull rope 11 is pulled in the proximal direction, the left side of the articulation ring 301 rotates around the joint 304 and is pulled towards each other. The distal end of the pre-curved spring bar 330 is fixed to the last articulation ring 301 at the distal end of the curved part, and the pre-curved spring bar 330 is slidable relative to the right eyelet 302 of the articulation ring 301, so that the articulation ring 301 can pivot around the joint 304. In doing so, the distance of the articulation ring 301 increases on its right side. The pre-curved spring bar 330 guided in the right eyelet 302 does not prevent the distance of the articulation ring 301 from increasing on its right side, since it is slidably supported in the right eyelet 302.

[0085] Thus, by pulling on the pull rope 11, the curved portion can be brought into an extended position in which the articulation rings 301 are aligned parallel to one another.

[0086] Starting from the extended position, as the pull rope 11 continues to be pulled in the proximal direction, the left sides of the articulation rings 301 continue to rotate (pivot) about the joint 304 and are pulled towards each other until they abut. In this situation, the articulation rings 301 are maximally spaced apart from each other on their right sides.

[0087] The straight portion of the pre-curved spring bar 330 in the non-activated state protruding proximally on the first articulation ring 301 has a length such that the curved portion can be bent at least 90 degrees to the left by pulling the pull rope 11, taking into account FIG. 8. The straight portion of the pre-curved spring bar 330 in the non-activated state protruding proximally on the first articulation ring 301 may also be designed to be longer. Taking into account FIG. 8, the curved portion can then be bent more than 90 degrees to the left by pulling the pull rope 11. The straight portion of the pre-curved spring bar 330 in the non-activated state protruding proximally on the first articulation ring 301 may also be designed to be shorter. Taking into account FIG. 8, the curved portion can then be bent less than 90 degrees to the left by pulling the pull rope 11. The pre-curved spring bar 330 may be provided with a stopper at the proximal end so that the proximal end of the pre-curved spring bar 330 cannot slip through the right eyelet 302 of the first articulation ring 301.

[0088] Fourth embodiment A fourth embodiment of the present invention will now be described with reference to FIG.

[0089] FIG. 9 is a schematic side view of the inside of a curved portion in the fourth embodiment.

[0090] The curved portion of the fourth embodiment similarly utilizes the known multi-joint structure described in the third embodiment and includes a multi-joint ring 301. A plurality of multi-joint rings 301 are arranged along the longitudinal direction of the curved portion. Adjacent joint rings 301 are connected to each other by joints 304 so that they can pivot toward each other about the axis of the joints 304. Thus, each pair of adjacent joint rings 301 has two joints 304 arranged 180 degrees apart from each other, i.e., diagonally on the joint rings 301. The first joint ring 301 at the proximal end of the curved portion has two joints 304 only on the distal side. The last joint ring 301 at the distal end of the curved portion has two joints 304 only on the proximal side.

[0091] Each articulation ring 301 has a right eyelet 302 and a left eyelet 302 around its periphery. The right eyelet 302 is located opposite the left eyelet 302. In other words, the position of the right eyelet 302 on the articulation ring 301 is spaced 180 degrees from the left eyelet 302, i.e., they are located at diagonal positions on the articulation ring 301. When viewed in the longitudinal direction of the curved portion, the left eyelets 302 are all in a row. Similarly, when viewed in the longitudinal direction of the curved portion, the right eyelets 302 are all in a row.

[0092] In FIG. 9, the left eyelet 302 is disposed on the left side of the articulated ring 301 , and the right eyelet 302 is disposed on the right side of the articulated ring 301 .

[0093] In the fourth embodiment, the pull rope 11 is guided in the left eyelet 302 of the articulation ring 301. In the fourth embodiment, the distal guided pull rope (not shown because it is hidden in FIG. 8) is guided in the right eyelet 302 of the articulation ring 301. The distal end of the pull rope 11 is fixed to the last articulation ring 301 at the distal end of the curved section. The distal end of the distal guided pull rope is fixed to the last articulation ring 301 at the distal end of the curved section. On the proximal side, a proximal spiral spring element 3300 is arranged (connected) on the distal guided pull rope. Said spiral spring element 330 forms an additional element. The tension of the spiral spring element 3300 predefines the bending direction of the curved section.

[0094] Essentially, the fourth embodiment differs from the third embodiment by the fact that instead of a pre-curved spring bar 330, a combination of a distal guided pull rope and a proximal spiral spring element 3300 is provided. The remaining aspects are the same. The description of the third embodiment is also applicable to the fourth embodiment. The combination of the distal guided pull rope and the proximal spiral spring element 3300 essentially constitutes a combined pull rope body that is tensioned as a whole. The proximal spiral spring element 330 is already under tension in the non-activated initial state. Thereby, the combination of the distal guided pull rope and the proximal spiral spring element 3300 is in a biased state that curves the curved portion already in the non-activated initial state radially outwards (see FIG. 9), and the combination of the distal guided pull rope and the proximal spiral spring element 3300 is placed in the curved portion.

[0095] The distal guided pull rope can have a length that extends, for example, through the biased curved portion, and the connection point to the proximal spiral spring element 3300 can be provided at the proximal end of the curved portion, before or after the proximal end of the curved portion. In the aforementioned unactuated state, the proximal spiral spring element 3300 protrudes proximally onto the first articulation ring 301 at the proximal end of the curved portion, or is located proximally from the curved portion, as shown in FIG.

[0096] The length of the combined distal guided pull rope and proximal spiral spring element 3300 can be selected to be similar to the length of the pre-curved spring bar 330 of the third embodiment.

[0097] The proximal spiral spring element 3300 is expandable. The proximal spiral spring element 3300 acts as a tension spring.

[0098] The proximal spiral spring element 3300 is biased such that the curved portion is pre-curved to one curved side, i.e., to the right in Fig. 9. In an embodiment, the curved portion is thus pre-curved by, for example, about 90 degrees, however, the degree of pre-curve may be selected as desired.

[0099] Due to the bias of the proximal spiral spring element 3300, the curved portion of this fourth embodiment in the unactuated state thus has a preset curvature to the side, i.e. to the right in Fig. 9. In this unactuated state, the right sides of the articulated rings 301 abut each other and the left sides of the articulated rings 301 are maximally spaced apart from each other.

[0100] At the left eyelet 302 of the articulation ring 301, the pull rope 11 is guided. Starting from the unactuated state of FIG. 9, as the pull rope 11 is pulled in the proximal direction, the left sides of the articulation ring 301 rotate about the joint 304 and are pulled towards each other. In doing so, on the right side of the articulation ring 301, held together by the bias of the proximal spiral spring element 3300, the combination of the distal guided pull rope and the proximal spiral spring element 3300 is stretched such that the right sides of the articulation ring 301 move away from each other as the articulation ring 301 rotates about the joint 304 (i.e. only the proximal spiral spring element 3300 is stretched).

[0101] Thus, by pulling on the pull rope 11, the curved portion can be brought into an extended position in which the articulation rings 301 are aligned parallel to one another.

[0102] Starting from the extended position, as the pull rope 11 continues to be pulled in the proximal direction, the left sides of the articulation ring 301 continue to rotate around the articulation 304 and are pulled towards each other until they abut. In this situation, the right sides of the articulation ring 301 are maximally spaced apart from each other and the proximal spiral spring element 3300 is maximally extended. The curved portion now faces leftwards, unlike in FIG. 9.

[0103] Fifth embodiment Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG.

[0104] FIG. 10 is a schematic side view of the inside of a curved portion in the fifth embodiment.

[0105] The fifth embodiment constitutes a further development of the fourth embodiment, in which the pull rope 11 is guided in the left eyelet 302 of the articulation ring 301 and the combination of the distal guided pull rope with the proximal spiral spring element 3300 is guided in the right eyelet 302 of the articulation ring 301.

[0106] In this fifth embodiment, in addition to the structure of the fourth embodiment, further eyelets are arranged on each articulation ring 301, offset by 90 degrees. On each articulation ring 301, four eyelets are arranged evenly distributed along the circumference, offset by 90 degrees. When viewed in the longitudinal direction of the curved portion, the left eyelets 302 are all aligned in a row. Furthermore, when viewed in the longitudinal direction of the curved portion, the right eyelets 302 are all aligned in a row. Also, when viewed in the longitudinal direction of the curved portion, all the front eyelets 302 are aligned in a row. Finally, when viewed in the longitudinal direction of the curved portion, all the rear eyelets 302 are aligned in a row.

[0107] In the left eyelet 302 of the articulation ring 301, a first pull rope 11 is guided. In the right eyelet 302 of the articulation ring 301, a first biased combination of a distal guided pull rope and a proximal spiral spring element 3300 is guided. In the front eyelet 302 of the articulation ring 301, a second pull rope 11 is guided. In the rear eyelet 302 of the articulation ring 301, a second biased combination of a distal guided pull rope and a proximal spiral spring element 3300 is guided. More precisely, in each respective combination of a distal guided pull rope and a proximal spiral spring element 3300, the distal guided pull rope is guided in the eyelet, and the proximal spiral spring element 3300 ensures the biasing.

[0108] Adjacent articulation rings 301 pivot towards each other about a joint 304. In the present invention, the joint 304 is meant to be a bearing that allows an articulation ring 301 to pivot to an adjacent articulation ring 301. The joint 304 includes a pivot axis about which the articulation ring 301 pivots relative to the adjacent articulation ring 301.

[0109] Adjacent articulation rings 301 are connected to each other by joints 304 so that they can pivot towards each other about the axis of the joints 304. Except for the first articulation ring 301 at the proximal end of the curved section and the last articulation ring 301 at the distal end of the curved section, each articulation ring 301 includes two joints 304 on the proximal side, spaced apart by 180 degrees from each other, i.e., diagonally positioned on the articulation ring 301. On the distal side, each articulation ring 301 includes two joints 304 on the proximal side, equally spaced apart by 180 degrees from each other, i.e., diagonally positioned on the articulation ring 301. The distal joints 304 are offset by 90 degrees around the articulation ring 301 relative to the proximal joints 304.

[0110] Thus, when viewed in the proximal and distal directions, the positions of the two joints 304 are provided such that they rotate approximately 90 degrees proximally and distally and then on the articulation ring 301. Thus, the articulation rings 301 can pivot relative to each other not only side to side but also forward and backward.

[0111] The first articulation ring 301 at the proximal end of the curved section includes only two distal joints 304. The last articulation ring 301 at the distal end includes only two proximal joints 304.

[0112] In the fourth embodiment, considering Figure 8, the curved portion can pivot left and right, thus in two directions. In this fifth embodiment, considering Figure 9, the curved portion can pivot in four directions, left and right and forward (towards the viewer) and backward (away from the viewer).

[0113] At the rear eyelet 302 and the right eyelet 302, the first and second combinations of the distal guided pull rope and the proximal spiral spring element 3300 are arranged to be biased. Thus, in the non-actuated state of FIG. 9, the respective areas of the adjacent articulated rings 301 located between the rear eyelet 302 and the right eyelet 302 are in abutment or have a minimum distance.

[0114] 9, when the first and second pull ropes 11 are pulled equally in the proximal direction, the left and front sides of the articulation ring 301 are rotated (pivoted) about the joint 304 and pulled towards each other. In doing so, the right and rear sides of the articulation ring 301, held together by the first and second biased combination of the distal guided pull rope and the proximal spiral spring element 3300, the first and second biased proximal spiral spring elements 3300, pull the right and rear sides of the articulation ring 301 away from each other (stretched and therefore expanded) as the articulation ring 301 is rotated (pivoted) about the joint 304.

[0115] When only the first pull rope 11 is pulled in the proximal direction, the distal end of the curved portion moves to the left.

[0116] When only the second pull rope 11 is pulled in the proximal direction, the distal end of the curved portion moves forward (towards the observer).

[0117] By combining the pulling and releasing movements of first pull rope 11 and second pull rope 11, the distal end of the curved portion can be pivoted in a desired direction in three-dimensional space.

[0118] The curved portion of the distal end 4 can be curved evenly left and right and forward (towards the viewer) and backward (away from the viewer), thus in four directions and all intermediate directions between.

[0119] Sixth embodiment Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG.

[0120] FIG. 11 is a schematic side view of the inside of a curved portion in the sixth embodiment.

[0121] The sixth embodiment is a further development of the third embodiment, in which the pull rope 11 is guided in the left eyelet 302 of the articulation ring 301 and in the right eyelet 302 of the articulation ring 301 a pre-curved spring bar 330 configured as an elastic wire is guided.

[0122] In this sixth embodiment, as in the fifth embodiment, in addition to the structure of the third embodiment, further eyelets are arranged in each articulation ring 301 offset by 90 degrees. Each articulation ring 301 has four eyelets arranged evenly distributed along the circumference, offset by 90 degrees. When viewed in the longitudinal direction of the curved portion, the left eyelets 302 are all aligned in a row. Furthermore, when viewed in the longitudinal direction of the curved portion, the right eyelets 302 are all aligned in a row. Also, when viewed in the longitudinal direction of the curved portion, all the front eyelets 302 are aligned in a row. Finally, when viewed in the longitudinal direction of the curved portion, all the rear eyelets 302 are aligned in a row.

[0123] In the left eyelet 302 of the articulation ring 301 a first pull rope 11 is guided. In the right eyelet 302 of the articulation ring 301 a first pre-curved spring bar 330 is guided. In the front eyelet 302 of the articulation ring 301 a second pull rope 11 is guided. In the rear eyelet 302 of the articulation ring 301 a second pre-curved spring bar 330 is guided. The first pre-curved spring bar 330 and the second pre-curved spring bar 330 are configured as pre-curved spring wires.

[0124] Adjacent articulation rings 301 pivot relative to one another about articulations 304 in a manner similar to the fifth embodiment.

[0125] The pre-curved spring bar 330 is pre-curved to the right similar to the third embodiment. For example, the pre-curved spring bar 330 is pre-curved about 90 degrees. However, the pre-curved angle may be selected as desired.

[0126] Due to the pre-curvature of the pre-curved spring bar 330, the curved portion is pre-curved to the side, i.e. to the right in Fig. 11, in the unactivated state. In said unactivated state, as in the fifth embodiment, the sides of the articulated ring 301 facing the pull rope 11 abut against each other. In said unactivated state, the sides of the articulated ring 301 arranged such that the pre-curved spring bar 330 is guided in its eyelet 302 are maximally spaced apart from each other.

[0127] The two pre-curved spring bars 330, as in the fifth embodiment, have a length that protrudes proximally on the first articulation ring 301 at the proximal end of the curved portion in the aforementioned non-actuated state, as shown in FIG. 11. The portion of the pre-curved spring bar 330 that protrudes proximally on the first articulation ring 301 in the non-actuated state has a straight extension (see FIG. 11). The pre-curved spring bar 330 is disposed in the right eyelet 302 of the articulation ring 301 and the rear eyelet 302 of the articulation ring 301, so that the pre-curved spring bar 330 is slidable relative to the right eyelet 302 of the articulation ring 301 and the rear eyelet 302 of the articulation ring 301.

[0128] Therefore, the structure and function of the sixth embodiment corresponds to a combination of the third and fifth embodiments.

[0129] In a sixth embodiment, considering FIG. 11, the curved portion is pivotable left and right and forward (towards the viewer) and backward (away from the viewer), thus in all four directions and all intermediate directions in between.

[0130] Further alternatives In the first embodiment, the pull rope 11 is disposed in a first chamber 31 located radially outward of the curved portion of the plate 30. There is no pull rope in a second chamber 32 located radially inward of the curved portion of the plate 30. The principles of the present invention can also be applied to a structure in which two or more pull ropes 11 are disposed in the first chamber 31 located radially outward of the curved portion of the plate 30. In this alternative example, there is also no pull rope in the second chamber 32 located radially inward of the curved portion of the plate 30.

[0131] In a second embodiment, a spring element 18 is interposed between the inner and outer circumferential surfaces of the sleeve 10. In one alternative, a spring element can be disposed on the inner circumferential surface of the sleeve 10 to provide the sleeve 10 with a desired elasticity and bending stiffness.

[0132] In a first embodiment, the elastic sleeve 10 of the curved portion 3 is distally continuous with the cover 21 of the insertion tube 2. In one alternative, the elastic sleeve 10 and the cover 21 may be a one-piece cover that extends from the control member to the distal tip 4 of the endoscope.

[0133] In a first embodiment, the flexible plate 30 is elongated and rectangular. The flexible plate 30 may also take other shapes. The cross section of the bendable plate 30 may be rectangular, elliptical, oval or racetrack shaped, etc. A racetrack shape (or stadium shape) has straight segments inserted between end pieces of semicircular type. Thus, one side of the separation element is longer than the other side. The separation element curves around the thinner side. In this way, when pulling the pull rope, the curvature direction is predetermined.

[0134] In an embodiment, the separating element is in the form of a flexible or bendable plate. The invention is not limited thereto. The separating element may also be manufactured as a partition already, for example, when the sleeve 10 is manufactured by extrusion. In this case, the separating element is integrally connected to the sleeve 10. To achieve sufficient pushing stability, a wire mesh can be integrated into the separating element.

[0135] In the third to sixth embodiments, an eyelet is used as the pull rope guide element. The present invention is not limited thereto. A pull rope guide element of a different structure can also be used to guide the pull rope. For example, a pull rope guide element having an open, semi-open, or closed guide body can be used. An eyelet is an example of a closed guide body. A guide body for guiding a pull rope does not need to be completely closed. In an open or semi-open design, the guide body has an incomplete enclosure that does not completely surround the guided pull rope.

[0136] In an alternative to the fourth and sixth embodiments, the combination of the distal guided pull rope and the proximal spiral spring element 3300 is replaced by a spiral spring element 3300. In this alternative, the biased spiral spring 3300 is guided in the right eyelet 302 of the articulation ring 301. The distal end of the biased spiral spring 3300 is fixed to the last articulation ring 301 at the distal end of the curved portion. The biased spiral spring 3300 has a length such that, in the previously described non-actuated state, it can protrude proximally on the first articulation ring 301 at the proximal end of the curved portion, as shown in FIG.

[0137] In the embodiment, both the optical system including the light guide 13 and the camera including the camera cable 12 are merely examples of uses of an endoscope according to the present invention and may be modified or omitted.

[0138] Alternatively, if the invention is applied to a larger endoscope, working ducts, rinsing ducts and / or ultrasonic sensors etc. may be provided.

[0139] Although the invention may be advantageously applied to flexible endoscopes, the principles of the invention may be applied to any type of endoscope that includes a curved portion. [Explanation of symbols]

[0140] 1 Endoscope 2 Insertion tube 3 Curved section 4 Distal end 10 Sleeve 11 Pull Rope 12 Camera cable 13 Light pipe 18 Spring elements 21 Cover 22 Wire Mesh 30 separation elements 31 First Chamber 32 Second Chamber 35 Distal portion of bendable plate 36 Proximal part of the bendable plate 301 Joint Ring 302 Eyelet 304 Joints 330 Pre-curved spring bars 3300 Spiral Spring

Claims

1. An endoscope (1), comprising: A flexible insertion tube (2); a proximally controllable curved portion (3) distally connected to said insertion tube (2); The curved portion (3) comprises a sleeve (10), A pull rope (11) extends within the curved portion (3) for pivotal movement of the curved portion (3), the pull rope (11) being fixed to a distal end of the curved portion (3); a separating element (30) which is curved in an unloaded state and divides the cross section of the sleeve (10) into two separate chambers (31, 32) is arranged in the longitudinal direction of the curved portion (3) parallel to the pull rope (11), the pull rope (11) is arranged in the longitudinal direction of the sleeve (10) for pivotal movement of the curved portion (3) in only one of the two chambers (31, 32) separated by the separating element (30), the chamber (31) being located outside the separating element (30) which is curved in an unloaded state, said separating element (30) being made of spring steel, stainless steel or a bendable plastic material; Endoscope (1).

2. said separation element (30) is fixed proximally to the distal end region of said insertion tube (2); An endoscope (1) according to claim 1.

3. The insertion tube (2) has an outer cover (21) and an elastic wire mesh (22) arranged under the outer cover (21), and the proximal side (36) of the separation element (30) is fixed to a distal end region of the wire mesh (22). An endoscope (1) according to claim 2.

4. the proximal side (36) of the separation element (30) is inserted into, welded to, or glued to the distal end region of the wire mesh (22); An endoscope (1) according to claim 3.

5. A cross-section of the separation element (30) is configured such that the cross-section of the separation element (30) is wider in a first direction and narrower in a second direction perpendicular to the first direction. An endoscope (1) according to any one of the preceding claims.

6. In the chamber (31) located on the outside of the curved separating element (30), a single pull rope (11) is arranged for the pivoting movement of the curved part (3), and in the other chamber (32) located on the inside of the curved separating element (30), no pull rope is arranged. An endoscope (1) according to any one of the preceding claims.

7. In the chamber (31) arranged on the outside of the curved separating element (30), a plurality of pull ropes (11) are arranged for the pivoting movement of the curved portion (3), and in the other chamber (32) arranged on the inside of the curved separating element (30), no pull ropes are arranged. An endoscope (1) according to any one of the preceding claims.

8. The sleeve (10) has an outer diameter of 3 mm or less. An endoscope (1) according to any one of the preceding claims.

9. The sleeve (10) of the curved portion (3) has an outer diameter of 1 mm or less. An endoscope (1) according to any one of the preceding claims.

10. The sleeve (10) of the curved portion (3) comprises a spring element (18). An endoscope (1) according to any one of the preceding claims.

11. the spring element (18) is embedded in the sleeve (10) of the curved portion (3); An endoscope (1) according to claim 10.

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