Flexible tube with compensating for steering wire path length

Abstract

The flexible tube (312) has a flexible end section (301) and a bendable body section (309). The flexible tube has one or more steering wires (16(i)) spiraling within the body section (309) to compensate for the difference in path length that occurs in the body section (309) when the body section (309) is bent. To block axial loads within the body section (309), the flexible tube (312) is provided with one or more longitudinal force blocking elements (322(k)) extending parallel to the one or more steering wires (16(i)) within the body section (309). The force blocking elements (322(k)) are attached at both ends to the outer tube (340) or the inner tube (330) or both.

Description

Technical Field

[0003]

[0001] The present invention relates to a flexible tube having a path length compensation for a steering wire. The present invention also relates to a flexible tube having an improved elastic hinge. The present invention also relates to an invasive instrument such as an endoscope including such a flexible tube.

Background Art

[0002] Converting a surgical intervention that requires a large incision to expose a target area into a minimally invasive surgical intervention, that is, a surgical intervention that requires only a natural opening or a small incision to establish access to the target area, is a well-known ongoing process. When performing a minimally invasive surgical intervention, an operator such as a physician requires an access device arranged to introduce and guide an invasive instrument into the body through an access port of a human or animal body. To reduce scar tissue formation and pain to a human or animal patient, the access port is preferably provided by a single small incision in the skin and underlying tissue. In some applications, a natural body opening can be used as an inlet. Further, the access device preferably enables an operator to control one or more degrees of freedom provided by the invasive instrument. In this way, the operator can perform the necessary operations in the target area within the human or animal body in an ergonomic and accurate manner with a reduced risk of collision of the instruments used.

[0003] Surgical invasive instruments and endoscopes are well known in the art. Both invasive instruments and endoscopes can include a steerable tube that improves their navigation and steering capabilities. Such a steerable tube can include a proximal end including at least one flexible region, a distal end including at least one flexible region, and an intermediate portion, and the steerable tube further includes a steering configuration adapted to convert at least a portion of the deflection of the proximal end relative to the intermediate portion into at least a portion of the associated deflection of the distal end. Alternatively, the distal flexible region can be steered by a robotic system disposed at the proximal end of the steerable instrument.

[0004] A maneuverable invasive instrument may include a handle positioned at the proximal end of the maneuverable tube for maneuvering the tube and / or for operating a tool positioned at the distal end of the maneuverable tube. Such a tool may be, for example, a camera, a manual manipulator, such as scissors, forceps, or a manipulator using an energy source, such as electricity, ultrasound, or optical energy source.

[0005] Furthermore, such a steerable tube may include several coaxially arranged cylindrical elements, including an outer cylindrical element, an inner cylindrical element, and one or more intermediate cylindrical elements, depending on the number of flexible regions within the proximal and distal ends of the tube and the desired implementation of the steering members of the steering configuration, i.e., all steering members may be located within a single intermediate cylindrical element, or the steering members may be divided into different sets, with each set of steering members located at least partially within different or the same intermediate cylindrical element. In most prior art devices, the steering configuration includes, for example, a conventional steering cable having a diameter of less than 1 mm as a steering member, and the steering cable is located between the relevant flexible regions at the proximal and distal ends of the tube. Other steering units at the proximal end, such as a ball-shaped steering unit or a robot-driven steering unit, may be applied instead.

[0006] However, steering cables have many well-known drawbacks, and in some applications, it may be desirable to avoid them and implement the steering member by one or more sets of steering wires forming an integral part of one or more intermediate cylindrical elements. Each of the intermediate cylindrical elements containing the steering wires can be manufactured by either using appropriate material addition techniques such as injection molding or plating, or by starting from a tube and then using conventional cutting techniques such as laser cutting, photochemical etching, deep drawing, drilling or milling, or appropriate material removal techniques such as a high-pressure waterjet cutting system. The steering wires thus manufactured can be implemented as longitudinal strips obtained from the tube material and used as pull / push wires. Of the material removal techniques described above, laser cutting is particularly advantageous because it allows for very precise and clean removal of material under reasonable economic conditions.

[0007] The inner and outer cylindrical elements can be manufactured from tubing. These tubing should be flexible at the distal end and optionally the proximal end of the instrument where bending is possible. At other locations where the instrument should be flexible, the inner and outer cylindrical elements should also be flexible. This can be implemented by providing hinges on the inner and outer cylindrical elements at these flexible locations. Such hinges may result from (laser) cutting a predetermined pattern into the tubing. Many different patterns are known from the prior art. The choice of pattern depends on the design requirements at the relevant location, including, but not limited to, the required bending angle, bending flexibility, longitudinal stiffness, and radial stiffness.

[0008] For example, as is known from flexible endoscopic instruments with maneuverable tips, flexible, invasive, maneuverable instruments can exhibit performance deficiencies with respect to the control of the maneuverable tip. When such a flexible instrument is inserted into the body through a curved channel (either an endoscope or a natural body lumen), the bending of the instrument causes movement of the longitudinal tip maneuvering element. In conventionally constructed instruments, the maneuvering element, such as a wire, is fixed proximal to a maneuvering device such as a handle and distal to the maneuverable tip, so the movement of the maneuvering wire results in bending of the maneuvering device and / or bending of the maneuverable tip. This causes problems when the instrument is advanced through a narrow, curved channel and when the maneuvering device is held in a fixed position, as the tip may bend uncontrollably during advancement, potentially becoming trapped, for example, within a narrow endoscopic working channel, or damaging tissue in a soft tissue natural body lumen, such as the lung bronchi or esophagus.

[0009] Another problem is that once the instrument passes through the entry channel and the instrument tip reaches the target surgical site, the tip's deflection no longer matches the deflection of the steering device. Therefore, the neutral position of the steering device does not correspond to the neutral position of the steerable tip. This offset negatively impacts the user's eye-hand coordination.

[0010] Another problem with flexible, maneuverable instruments is that when the tip is steered by the maneuvering element, the entire body behaves mechanically like the maneuverable tip, and therefore the body is also steered by the maneuvering element. The ratio of deflection between the body and the tip simply depends on the bending stiffness of the body and the tip. The stiffer the body is relative to the stiffness of the tip, the more the tip is steered. In practice, the tip is more flexible than the body, but when the tip is steered, the body also flexes, resulting in lateral forces acting on the surrounding channels and tending to maintain the instrument body at a certain curvature. This is highly undesirable instrument behavior, as lateral forces can damage surrounding tissue if soft body tissue is present in the surrounding channels. Body movements can also interfere with the positioning of the maneuverable tip at the target site, making accurate and predictable tip steer more difficult.

[0011] This problem arises because different sections of the steering wire inside the flexible body of the device end up with different lengths inside the body due to bending. Therefore, this will be explained with reference to Figures 1A and 1B.

[0012] Figure 1A shows the body of a tubular device 1, which has a first steering wire 16(1) extending linearly from one end to the opposite end on one side of the body, and a second steering wire 16(2) extending linearly from one end to the opposite end on the other side of the body, i.e., a position rotated 180 degrees. The steering wires extend parallel to each other. The tube 1 has a central axis of symmetry 29. The body of the tube 1 has a length L. In the unbent state of Figure 1A, both steering wires 16(1) and 16(2) also have a length L within the body.

[0013] Figure 1B shows the bent position, in this case the tube 1 bent 180 degrees. In this state, the length of the shaft 29 inside the body remains the same. However, the portion of the steering wire 16(1) located inside the bend extends from the body with an offset of +ΔL, while the portion of the steering wire 16(2) located outside the bend extends inside the body with an offset of -ΔL. In other words, steering wire 16(1) is pushed out of the body, and steering wire 16(2) is retracted into the body. Since steering wires 16(1) and 16(2) are attached to the tip of the instrument, this causes one or more of the aforementioned problems, such as undesirable bending of the tip.

[0014] As known from prior art, this undesirable effect can be compensated for by spiraling the steering wires 16(1) and 16(2) 180 degrees around the body, as schematically shown in Figure 2A. In Figure 2A, the 180-degree spiral of the steering wires 16(1) and 16(2) is implemented in the central section of the body. As shown in Figure 2B, when the body in Figure 2A is bent in a 180-degree curve, both steering wires 16(1) and 16(2) are positioned with half of their length inside the bent body and the other half outside the bent body. Thus, both have a shorter portion inside the bent body and a longer portion outside the bent body than in the state of Figure 2A, and thus compensate for the difference in path length due to the bending of the body.

[0015] One prior art solution based on the technology shown in Figure 2B is known from U.S. Patent No. 4,745,908. This patent describes an invasive instrument having a flexible tip. The flexibility is caused by a cable located inside a conduit. Both the cable and the conduit extend from the proximal end to the tip at the distal end. The conduit's path is spiral around the longitudinal axis of the core.

[0016] Due to the substantially constant overall length of the conduit generated by the non-linear conduit path, the cable length and conduit length remain relatively equal even when the instrument shaft is bent or located within a bent channel path and is twisted or torqued to rotate the objective lens head. Because the cable length and conduit length remain relatively equal, there is no involuntary or uncontrolled deflection at the distal end of the instrument.

[0017] This known technology is sometimes referred to as Bowden cable technology. Another term used in this art is "coiled pipe." Other prior art can be found, for example, in U.S. Patent Application Publication No. 20110004157A1, U.S. Patent Application Publication No. 20080300462A1, International Publication No. 2009048796A2, Korean Patent No. 101312071B1, International Publication No. 2015084174, International Publication No. 2016063348A1, U.S. Patent Application Publication No. 2018055589A1, International Publication No. 2020016577A1, and International Publication No. 2022260518. [Prior art documents] [Patent Documents]

[0018] [Patent Document 1] U.S. Patent Application Publication No. 2011 / 0004157 [Overview of the project] [Means for solving the problem]

[0019] In a first aspect, an object of the present invention is to provide a maneuverable instrument for endoscopic and / or invasive applications that solves or at least reduces at least one of the above-described problems.

[0020] This is achieved by the steering device described in the attached independent claim 1.

[0021] The force blocking element blocks the axial load of the invasive instrument from the bendable body portion, and the axial load causes the steering wire to be pulled / pushed in to bend the bendable tip portion. Since the steering wire is helical in at least a part of the body section, when the body section bends, at least a part of the path length difference can be compensated. Further, since the longitudinal force blocking elements extend through the body portion parallel to the steering wire, they are likewise helical, and as a result, at least some path length compensation is also provided for the longitudinal force blocking elements of the body portion itself.

[0022] Embodiments of the first aspect of the present invention are described in the claims dependent on claim 1.

[0023] In a second aspect, the present invention relates to an improved hinge structure as described in independent claim 17.

[0024] Embodiments of the second aspect of the present invention are described in the claims dependent on claim 17.

[0025] Further features and advantages of the present invention will become apparent from the description of the present invention by way of non-limiting and non-exclusive embodiments. These embodiments should not be construed as limiting the scope of protection. Those skilled in the art will understand that other alternative and equivalent embodiments of the present invention can be devised and implemented without departing from the scope of the present invention. Further, the distinct features of different embodiments can be combined even if not explicitly shown in the drawings or described herein, as long as such a combination is not physically impossible. The scope of the present invention is limited only by the claims and their technical equivalents. Embodiments of the present invention are described with reference to the figures of the accompanying drawings, and like or identical reference numerals indicate like, identical or corresponding parts.

Brief Description of the Drawings

[0026] [Figure 1A] A schematic diagram is shown for introducing some of the problems addressed by the first aspect of the present invention. [Figure 1B] The same as above.

[0027] [Figure 2A] Shows a schematic solution of the prior art to the problems shown in FIGS. 1A and 1B. [Figure 2B] The same as above.

[0028] [Figure 3A] Shows a prior art tube of a steerable instrument having a steering wire made from the tube wall. [Figure 3B] The same as above.

[0029] [Figure 4] Shows a schematic perspective view of a tube having a steering wire made from the tube wall.

[0030] [Figure 5A] Shows a schematic perspective view of an alternative tube having a steering wire made from the tube wall.

[0031] [Figure 5B] Shows an enlarged view of the distal portion of the tube shown in FIG. 5A.

[0032] [Figure 5C] Shows a schematic cross-sectional view of some components of the proximal portion of a steerable instrument. <​​​​​​​​​​​​​​​​​​​​​​​

[0036] [Figure 6] Examples of inner tubes that can be used inside the pipes shown in Figures 4, 5A, 5B, and 5C are shown.

[0037] [Figure 7] Figures 4, 5A, 5B, and 5C show examples of the tip and body portions of an outer tube that can be used on the outside of the tube shown.

[0038] [Figure 8] This shows a hinge structure using conventional technology.

[0039] [Figure 9] A portion of an embodiment of a hinge structure according to a second aspect of the present invention is shown. [Figure 10] Same as above. [Figure 11] Same as above. [Figure 12A] Same as above. [Figure 12B] Same as above. [Figure 12C] Same as above. [Modes for carrying out the invention]

[0040] In one embodiment, the present invention is implemented using a tube provided with an appropriate cutting pattern, which is also referred to below as a "cylindrical element." The basic technology of such a tube is described, for example, in European Patent No. 2273911 B1. Figure 3A shows an exploded view of three cylindrical members forming an instrument according to European Patent No. 2273911 B1. The instrument 202 consists of three coaxial cylindrical members: an inner member 204, an intermediate member 206, and an outer member 208. The inner cylindrical member 204 consists of a first rigid, steerable end portion 210, which is a part typically used in surgical locations that may be difficult to reach, such as inside the human body; a first flexible portion 212; an intermediate rigid portion 214; a second flexible portion 216; and a second steerable rigid end portion 218. The steerable end portion 210 is located at the distal end of the instrument. The steerable rigid end is located at the proximal end of the instrument.

[0041] The outer cylindrical member 208 is similarly composed of a first steerable rigid portion 201, a flexible portion 203, an intermediate rigid portion 205, a second flexible portion 207, and a second steerable rigid portion 209. The flexible portions of the cylindrical members 204 and 208 are also referred to in the art as "hinge." The lengths of the different portions of the cylindrical members 208 and 212 are substantially the same so that when the cylindrical member 204 is inserted into the cylindrical member 208, the steerable end portions 210 and 201, the flexible portions 212 and 203, the rigid portions 214 and 205, the flexible portions 216 and 207, and the rigid steerable end portions 218 and 209 are aligned with each other.

[0042] The intermediate cylindrical member 206 also has, in its assembled state, a first steering rigid end portion 240 and a second steering rigid end portion 242, which are respectively located between the corresponding rigid steering end portions 210, 201 and rigid steering end portions 218, 209 of the two other cylindrical members 204, 208.

[0043] Components 216, 218, 242, 207, 209, and the portion of 211 aligned axially with components 216 and 207, together form the steering unit 244 of the steering device. Components 210, 212, 240, 201, 203, and the portion of 211 aligned axially with components 212 and 203, together form the steering portion or flexible portion 248 of the steering device. The portion between the steering unit 244 and the steering portion 248 is the main body portion 246.

[0044] The intermediate cylindrical member 206 has an intermediate portion 211 formed by one or more, for example, three separate longitudinal elements 16(i) (i=1, 2, ..., I) which may have different forms and shapes. These longitudinal elements are made from the wall material of the intermediate cylindrical member 206 and therefore have the form of longitudinal strips. Since they act as steering wires, they will hereafter be referred to as "steering wires". After the three cylindrical members are assembled, cylindrical member 204 is inside cylindrical member 206, and the two combined cylindrical members 204, 206 are inside cylindrical member 208, and the rigid steering end portions 218, 242, 209 of the three cylindrical members can be attached to each other. Furthermore, the steerable end portions 210, 240, 201 can be attached to each other. The steering end portions 218, 242, and 209 are located at the proximal end of the invasive device, while the steering end portions 210, 240, and 201 are located at the distal end of the invasive device.

[0045] The three cylindrical members 204, 206, and 208 are all shown in a straight line extending in the axial (or longitudinal) direction. As will be apparent to those skilled in the art, by bending the steering end portions 218, 242, and 209 of the assembled device away from the axial direction, the steering end portions 210, 240, and 201 are bent away from the axial direction so that some of the steering wires 16(i) generate tensile forces and other steering wires 16(i) generate compressive forces.

[0046] Figure 3B, also known from European Patent No. 2273911B1, shows a developed view of part of an alternative embodiment of the intermediate cylindrical member of the device in Figure 3A. The intermediate cylindrical member in Figure 3B is formed by a number of steering wires 16(i), each steering wire 16(i) consisting of three parts 222, 224, and 226 coexisting with a first flexible portion, an intermediate rigid portion, and a second flexible portion, respectively. In part 224, which coincides with the intermediate rigid portion, each pair of adjacent longitudinal elements 220 are very close to each other in the tangential direction, and as a result, only a narrow gap exists between them that is just enough to allow independent movement of each longitudinal element.

[0047] In the other two sections 222 and 226, each longitudinal element consists of relatively small and flexible strips 228 and 230 when viewed circumferentially, so that there is a substantial gap between each pair of adjacent strips, and each of the strips 228 and 230 is provided with a number of cams 232 that extend circumferentially and substantially bridge the gap to the next strip.

[0048] The cylindrical elements shown in Figures 3A and 3B can be manufactured entirely by cutting an appropriate cutting pattern into a tube, for example, by laser cutting. Thus, the steering wire 16(i) is a strip manufactured from the wall of the cylindrical element 206.

[0049] These also demonstrate the basic techniques used in the cylindrical elements of the present invention. Other examples of maneuverable invasive instruments manufactured by (laser) cutting appropriate patterns into cylindrical elements are, for example, in International Publication Nos. 2009112060, 2009127236, 2012128618, 2012173478, 2014011049, 2015084174, 2016089202, 2017010883, 2017014624, International Publication Nos. This can be found in Publication No. 2017082720, International Publication No. 2017213491, International Publication No. 2018067004, International Publication No. 2019009710, International Publication No. 2020080938, International Publication No. 2020214027, International Publication No. 2020218920, International Publication No. 2020218921, International Publication No. 2022260518, International Publication No. 2023287286, and International Publication No. 2023287289. Other such examples may relate to devices having two or more steerable ends and / or having a flexible intermediate section instead of a rigid intermediate section.

[0050] Path length compensation Figure 4 shows an example of a pipe 306 implementing the solutions of Figures 3A and 3B. The figure shows the distal portion at the distal end of the pipe 306. The illustrated implementation has a ring-shaped end portion 300. Proximal to the ring-shaped end portion 300, the pipe 306 has one or more steering wires 16(i) (i=1, 2, ..., I), where I=4, but I can have any other suitable value. The four steering wires 16(i) are divided at equidistant intervals around the pipe 306. All steering wires 16(i) are attached to the ring-shaped end portion 300, for example, by cutting them from the same wall of the pipe 306 as the ring-shaped end portion 300. More steering wires or portions thereof can be present within the pipe 306, for example, so that some of them extend to a further flexible region at the distal end.

[0051] The distal portion has a flexible tip section 301 that can be flexed by appropriate longitudinal movement of four steering wires 16(i). In the flexible tip section 301, adjacent steering wires 16(i) are separated by spacers 304(i). The spacers 304(i) are located between the steering wires 16(i) and 16(i+1) when viewed circumferentially. Each spacer 304(i) can be fabricated from the wall of the tube 306 by providing an appropriate cutting pattern in the wall material between adjacent steering wires 16(i) such that the resulting spacer 304(i) has sufficient flexibility to maintain adjacent steering wires 16(i) at a desired tangential distance and simultaneously allow flexing of the flexible tip section 301. The flexibility depends on the cutting pattern used. Possible cutting patterns are described below using reference no. 316(i) (see Figure 5B).

[0052] Proximal to the flexible tip section 301, the tube 306 has a main body section 309 having three sub-body sections 303, 305, and 307. In sub-body section 303, adjacent to the flexible tip section 301, all steering wires 16(i) are linear and extend parallel to each other and to the central axis 29. In the next sub-body section 305, adjacent to sub-body section 303, all steering wires 16(i) are spirally 180 degrees parallel to the central axis 29. Sub-body section 307 extends proximal to sub-body section 305. In sub-body section 307, all steering wires 16(i) are linear and extend parallel to each other and to the central axis 29.

[0053] In all sections 301, 303, 305, and 307 of pipe 306, all steering wires 16(i) may have the same thickness and width. However, depending on the design, the thickness and / or width of all steering wires 16(i) may differ from section 301, 303, 305, and 307, provided that they are flexible along the entire length of the tip and body sections.

[0054] Spacers 302(i) (i=1, 2, ...I) are each located between adjacent steering wires 16(i) in the main section 309. The spacers 302(i) are designed to keep adjacent steering wires at a predetermined distance from each other while still allowing the bending of the main sections 303, 305, and 307. The spacers 302(i) can be fabricated from the wall of the tube 306 by providing a wall with a suitable cutting pattern 310.

[0055] The position of the sub-body section 305 in which the steering wire 16(i) is spiraled 180 degrees can be selected according to the application of the tube 306, i.e., knowledge of the curved channel into which the tube 306 is inserted. If the main body section 309 is bent due to the insertion of the tube 306 into the curved channel, the difference in the path length of the wire 16(i) in the sub-body sections 303, 305, and 307 caused by the bend is compensated for by the spiral in the sub-body section 305, as described with reference to Figures 2A and 2B.

[0056] The tube 306 shown in Figure 4 may have two or more sub-body sections 305 in which the steering wire 16(i) is helical at 180 degrees. They may be continuous with each other or separated by sub-body sections in which the steering wire 16(i) extends linearly parallel to the central axis 29, such as sub-body section 307. The size of the 180-degree helix pitch depends on the application. In an alternative embodiment, the steering wire 16(i) is helical throughout the entire body section 309 (i.e., there are no sub-body sections 303, 307). To compensate as much as possible for the difference in path length between the steering wires 16(i) inside the body section 309 due to the bending of the body section, the total helix in the body section 309 between the distal and proximal ends is an integer multiple of 180 degrees.

[0057] At its proximal end, the main body section 309 is connected to or attached to a steering section indicated by reference numeral 354 in Figure 5C. Such a steering section 354 is configured to move the steering wire 16(i) longitudinally of the device, and as a result, they together can bend the flexible end section 301. To this end, the steering section 354 may include a flexible portion configured to convert the bending motion into such movement of the steering wire 16(i), as is known in the art, as shown, for example, in Figures 3A and 3B. Alternatively, the longitudinal movement of the steering wire 16(i) may be controlled by a robotic steering section, as is known in the art, by directly controlling the longitudinal movement of the steering wire 16(i) at individual levels.

[0058] Figures 5A, 5B, 5C, 5D, 6, and 7 illustrate one embodiment of a first aspect of the present invention. Figure 5A shows an inner tube 330 coaxially surrounded by an intermediate tube 312. An outer tube 340, an example of its distal end and body section shown in Figure 7, may be provided coaxially with the inner tube 330 and the intermediate tube 312. Figure 5B shows an enlarged view of an example of the distal end and body section of the intermediate tube 312. Figure 5C shows a cross-sectional view of several components at the proximal end of the device. Figure 6 shows an enlarged view of an example of the distal end and body section of the inner tube 330.

[0059] In the embodiment shown in Figure 5A, the intermediate pipe 312 also has a flexible tip section 301 and a flexible body section 309 proximal to the flexible tip section 301.

[0060] The implementation shown in Figure 5A has a ring-shaped end portion 314. Proximal to the ring-shaped end portion 314, the intermediate pipe 312 has one or more steering wires 16(i) (i=1, 2, ..., I). Here, I=4, but I can have any other suitable value as described above. The four steering wires 16(i) are divided at equidistant intervals around the intermediate pipe 312. All steering wires 16(i) are attached to the ring-shaped end portion 314, for example, by cutting them from the wall of the same pipe 312 as the ring-shaped end portion 314.

[0061] The flexible tip section 301 can bend in all directions in 3D space by four steering wires 16(i). In the flexible tip section 301, adjacent steering wires 16(i) are separated by spacers 316(i). The spacers 316(i) are located between the steering wires 16(i) and 16(i+1) when viewed circumferentially. Each spacer 316(i) can be fabricated from the wall of the intermediate tube 312 by providing an appropriate cutting pattern in the wall material between adjacent steering wires 16(i) such that the resulting spacer 316(i) has sufficient flexibility to maintain adjacent steering wires 16(i) at a desired tangential distance and simultaneously allow the flexible tip section 301 to bend. The flexibility depends on the cutting pattern used. Possible cutting patterns for spacers 316(i) are described below with reference to Figure 5B.

[0062] As shown in Figure 5B, the spacers 316(i) have a spring-shaped design. In the tangential direction of the pipe 312, each spacer 316(i) extends from one steering wire 16(i) to the adjacent steering wire 16(i+1) and has a tangential cross-section equal to the tangential cross-section of the pipe 312. In one embodiment, the spacers 316(i) are not attached to the steering wires 16(i). In the axial direction of the pipe 312, the spacers 316(i) have a regular repeating pattern, such as a block wave pattern, as shown. At their distal ends, each spacer 316(i) may be attached to a ring-shaped end portion 314. However, the repeating pattern may vary and may more closely resemble a sinusoidal wave pattern. Such a repeating pattern can be easily formed by providing appropriate cutting patterns in the walls of the pipe 312. Such spacer 316(i) having a block wave pattern has the advantage of providing a tip section 301 that is highly flexible in all directions while also being highly rigid against torque, as it fills many spaces between adjacent steering wires 16(i).

[0063] In the main section 309, adjacent to the flexible end section 301, all steering wires 16(i) extend parallel to each other in a continuous helical manner. In this embodiment, along the entire length of the main section 309, the steering wires 16(i) are helical in integer multiples of 180 degrees to compensate for the difference in path length between them inside the main section 309 when the main section 309 is bent. However, the total amount of helix depends on design requirements. For example, it may be desirable to have a different amount of helix to bend the end section in a specific plane different from the plane that bends the steering section at the proximal end. In that case, the helicalization may not fully compensate for the difference in path length of the main section resulting from the bending of the main section. However, this can be compensated by a Bowden cable configuration at the proximal end of the device, as described and shown, for example, in International Publication No. 2022260518A1.

[0064] In all sections 301, 309 of the pipe 312, all steering wires 16(i) may have the same thickness and width. However, depending on the design, the thickness and / or width of all steering wires 16(i) may differ from section 301, 309, provided they are flexible along the entire length of the main section.

[0065] Proximal to the flexible tip section 301, in one embodiment, the tube 312 is provided with solid-filled spacers 318(i), the distal end of which, in one embodiment, is attached to one of the spacers 316(i). Each solid-filled spacer 318(i) is located between adjacent steering wires 16(i) and 16(i+1) and, in one embodiment, is attached to the inner spacer 316(i) of the flexible tip section 301. The solid-filled spacers 318(i) are designed to keep adjacent steering wires 16(i) and 16(i+1) separated from each other at a desired tangential distance in the main section 309. Reference numeral 319(i) refers to the position on the solid-filled spacer 318(i) where portions 350(i) of the outer tube 340 and / or inner tube 330 are attached to the solid-filled spacer 318(i) (see Figure 7 below).

[0066] Between each pair of adjacent steering wires 16(i), 16(i+1), pairs of spacers 320a(i), 320b(i) extend proximal to the pipe 312 from the solid-filled spacer 318(i) in the main section 309. Note that in this specification, the notation "16(i), 16(i+1)" includes adjacent pairs "16(I), 16(1)". Each pair of spacers 320a(i), 320b(i) is separated by longitudinal force-blocking elements 322(k), k=1, 2, ...K. K may be equal to I, but is not required. Each longitudinal force-blocking element 322(k) is attached to the solid-filled spacer 318(i) at its distal end. As shown, the longitudinal force blocking element 322(k) may extend within the solid-filled spacer 318(i) by providing a solid-filled spacer 318(i) having two longitudinal slits. This provides greater flexibility in the region of the solid-filled spacer 318(i) relative to the main body section 309.

[0067] Here, one embodiment is shown having the same number of longitudinal force-sheltering elements as the number of steering wires 16(i). However, this is not strictly necessary. For example, there may be more or fewer than one longitudinal force-sheltering elements 322(k) between two adjacent steering wires 16(i). Each longitudinal force-sheltering element 322(k) is shown to have an equal tangential distance to adjacent steering wires 16(i), 16(i+1). This is not strictly necessary.

[0068] The spacer pairs 320a(i) and 320b(i), along with the material of the longitudinal force blocking element 322(k), are designed to maintain adjacent steering wires at a predetermined distance from each other and to allow bending of the main body section 309. The spacer pairs 320a(i) and 320b(i) can be fabricated from the walls of the tube 306 by providing the walls with appropriate cutting patterns 310. For example, the cutting pattern 310 may include multiple sets of slits, each set of slits including several parallel slits that extend tangentially from the first side of one spacer of the spacer pair 320a(i), 320b(i) toward the second side of that spacer, but not entirely to the second side of that spacer, and several more parallel slits that extend tangentially from the second side of one spacer of the spacer pair 320a(i), 320b(i) toward the first side of that spacer, but not entirely to the first side of that spacer. However, this is only one example of a cutting pattern 310. The flexibility of the main body section 309 may be less than the flexibility of the flexible end section 301.

[0069] To provide a tube 306 with higher rigidity against torque, the spacer pair 320(i) may be provided with one or more through-holes 324, each through-hole designed to receive a lip radially bent from the inner tube 330 and / or outer tube 340. Figure 7 shows such a lip 352 in the outer tube 340. When the lip 352 is bent into the through-hole 324, the spacer pairs 320a(i), 320b(i) have less room for tangential and axial movement of the lip 352 relative to the inner tube 330 or outer tube 340. Tangential movement of the spacer pairs 320a(i), 320b(i) relative to the inner tube 330 and / or outer tube 340 is prevented as much as possible by these lips 352, but axial movement of the spacer pairs 320a(i), 320b(i) relative to the inner tube 330 and / or outer tube 340 is preferably allowed up to a certain maximum amount.

[0070] The longitudinal force isolation elements 322(k) are not attached to adjacent spacer pairs 320a(i) and 320b(i) on their longitudinal sides, and these spacer pairs are not attached to adjacent steering wires 16(i). Depending on the design requirements, the longitudinal force isolation elements 322(k) may have the same thickness and width as the steering wires 16(i). Together with the steering wires 16(i) and the spacer pairs 320a(i) and 320b(i), they should provide the necessary flexibility to the main body section 309 to allow insertion into a curved channel.

[0071] Each longitudinal force-blocking element 322(k) has a proximal end located at the proximal end of the main body section 309. The proximal ends of each longitudinal force-blocking element 322(k) are attached to at least one of the proximal portions of the outer tube 340 or the inner tube 330. This is shown in Figure 5C, which shows a schematic longitudinal section of the proximal end of the flexible main body portion 356 of the invasive device. The invasive device includes an inner tube 330, an intermediate tube 312, and an outer tube 340. The section in Figure 5C shows two opposing longitudinal force-blocking elements 322(1) and 322(3), respectively. They are attached to at least one of the inner tube 330 or the outer tube 340 using mounting portions 326(1) and 326(3), respectively, at or near the proximal end of the main body portion 356. Mounting portions 326(k) for all longitudinal force-blocking elements 322(k) may be manufactured by (laser) melting or any other suitable method.

[0072] The steering wire 16(i) extends proximal from the proximal end of the main body portion 356 to the steering unit 354 of the invasive device, which is schematically shown as a box in Figure 5C. Such a steering unit 354 may be implemented as a proximal flexible unit or robotic device, such as the steering unit 244 schematically shown in Figure 3A. The steering wire 16(i) may be configured to be easily coupled to or detached from a suitable drive mechanism for a manually operated steering handle or robotic device, such as those described in International Publication No. 2020218920, International Publication No. 2020218921, or Dutch Patent No. 2030160B1. The steering unit 354 may be configured to convert the bending or longitudinal movement of one or more drive mechanisms into longitudinal movement of the steering wire 16(i).

[0073] Figure 6 shows a portion of the inner tube 330 distal to the instrument. The inner tube 330 has a ring-shaped end section 332, a flexible tip section 334 proximal to the ring-shaped end section 332, a rigid ring-shaped section 336 proximal to the flexible tip section 334, and a bendable body section 338 proximal to the ring-shaped section 336. When the inner tube 330 is inserted into the intermediate tube 312 at a desired axial position, the ring-shaped end section 332 aligns axially with the ring-shaped end portion 314, the flexible tip section 334 aligns axially with the bendable tip section 301, the rigid ring-shaped section 336 aligns axially with the solid filling spacer 318(i), and the bendable body section 338 aligns axially with the flexible spacer pair 320a(i) and 320b(i). The flexibility of the flexible tip section 334 may be higher than the flexibility of the bendable body section 338.

[0074] The flexible tip section 334 is provided with the desired flexibility by creating an appropriate cutting pattern in the inner tube 330. This can be any cutting pattern known in the art or not yet developed. One example may be a cutting pattern shown by reference no. 360 in Figure 7 and described in detail with reference to hinges 407(j), j=1, 2, ..., J in Figures 9-12C.

[0075] The flexible body section 338 is provided with the desired flexibility by creating an appropriate cutting pattern in the inner tube 330. This can be any cutting pattern known in the art or not yet developed. One example may be a cutting pattern shown by reference numeral 360 in Figure 7 and described in detail with reference to hinge 407(j) in Figures 9–12C.

[0076] The rigid ring-shaped section 336 can be attached to all solid-fill spacers 318(i) within the intermediate pipe 312.

[0077] Figure 7 shows a portion 358 of an invasive instrument having a coaxially arranged inner tube 330, intermediate tube 312, and outer tube 340. The figure shows a detail of the outer tube 340. This figure also shows the tip portion 358 and the body portion 356. The body portion 356 is configured to be connected to or attached to a steering unit 354 (see Figure 5C) at its proximal end, or to be coupled to the steering unit 354.

[0078] The outer tube 340 has a ring-shaped end section 342, a flexible tip section 344 proximal to the ring-shaped end section 342, a rigid ring-shaped section 346 proximal to the flexible tip section 344, and a bendable body section 348 proximal to the ring-shaped section 346. When the inner tube 330 and the intermediate tube 312 are inserted into the outer tube 340 at the desired axial position, the ring-shaped end section 342 aligns axially with the ring-shaped end sections 314 and 332, the flexible tip section 344 aligns axially with the flexible tip section 334 and the flexible tip section 301, the rigid ring-shaped section 346 aligns axially with the ring-shaped section 336 and the solid filler spacer 318(i), and the bendable body section 348 aligns axially with the bendable body section 338 and the flexible spacer pair 320a(i), 320b(i). The flexibility of the flexible tip section 344 may be higher than the flexibility of the bendable body section 348.

[0079] The flexible tip section 344 is provided with the desired flexibility by forming an appropriate cutting pattern in the outer tube 340. This can be any cutting pattern known in the art or not yet developed. One example may be a cutting pattern shown by reference numeral 360 in Figure 7 and described in detail with reference to hinge 407(j) in Figures 9–12C.

[0080] The flexible body section 348 is provided with the desired flexibility by forming an appropriate cutting pattern in the outer tube 340. This can be any cutting pattern known in the art or not yet developed. It can be the same cutting pattern applied to the flexible tip section 344.

[0081] The rigid ring-shaped section 346 can be attached at position 350(j) to all solid-fill spacers 318(i) within the intermediate tube 312. That is, each of the solid-fill spacers 318(i) within the intermediate tube 312 is attached to at least one of the ring-shaped section 336 of the inner tube 330 or the ring-shaped section 346 of the outer tube 340. This can be done by (laser) welding or any other known attachment technique. For this purpose, the outer tube 340 may have small lips at position 350(j), which may be melted by a laser beam, and as a result the molten lip material is welded to the solid-fill spacers 318(i).

[0082] Figure 7 also shows that the main section 348 may be provided with one or more lips 352. When the intermediate pipe 312 (and possibly the inner pipe 330 as well) is bent inward, each of these lips 352 is inserted into one of the through-holes 324 of the spacer pair 320a(i), 320b(i). Once inside these through-holes 324, they restrict the tangential and axial movement of the spacer pair 320a(i), 320b(i) relative to the outer pipe 340.

[0083] In a further embodiment, as shown in Figure 5D, the force-blocking element 322(k) itself may be provided with a through-hole 325 through which the lips of the inner tube 330 and / or outer tube 340 are inserted, as shown in Figure 7 with a lip 352. Then, tangential movement of the force-blocking element 322(k) relative to the inner tube 330 and / or outer tube 340 is blocked as much as possible by these lips, while axial movement of the force-blocking element 322(k) relative to the inner tube 330 and outer tube 340 is permitted up to a certain maximum amount. Furthermore, such a through-hole 325 is configured to provide the force-blocking element 322(k) with a certain degree of flexibility necessary to allow the body section 309 to bend, and also to provide sufficient longitudinal rigidity. That is, the desired flexibility of the force-blocking element 322(k) can be achieved by an appropriate selection of the axial length and / or tangential width of the through-hole 325.

[0084] Figure 5E shows an alternative embodiment of the embodiment in Figure 5D in which the through-holes are in the form of long slots 325, so that it can also be said that the force-blocking element 322(k) is divided into two parallel force-blocking sub-elements 322(k,1) and 322(k,2) attached to each other by one or more small bridges 323 extending tangentially or at a small angle thereto. The lengths of the slots 325 may all be equal. However, they may be designed differently so that the bending stiffness of the main body section of the fixture differs depending on the axial position.

[0085] As those skilled in the art will understand, the bending stiffness of the main body shown in Figure 5E strongly depends on the portions 322(k,1), 322(k,2), and 323 of the force-blocking element whose tangential direction extends at a small angle with respect to the bending direction at all locations. The portions 322(k,1), 322(k,2), and 323 of the force-blocking element that do not bend at all or bend at an angle close to 90 degrees with respect to the bending direction of the device have little effect on the bending stiffness if the thickness of the force-blocking element is less than their width.

[0086] The actual bending stiffness of the main body section at its axial position depends on whether there is a slot 325 or a bridge 323 at that axial position. If there is a bridge 323, the bending stiffness is greater than if there is a slot 325.

[0087] Naturally, the force shielding 322(k) can be divided into three or more force shielding sub-elements.

[0088] At the axial position where slot 325 is located, the bending stiffness of the main body section depends on the widths w1 and w2 (measured tangentially) of two parallel force-blocking sub-elements 322(k,1) and 322(k,2) (see Figure 5E). These individual widths w1 and w2 may be equal or different. These widths w1 and w2 may also vary depending on the axial position.

[0089] The actual bending stiffness also depends on the thickness of the force-blocking elements 322(k,1) and 322(k,2). A flat, strip-shaped wire with a rectangular cross-section having width w at a particular position has an area moment of inertia I at that position, where I∝t*w^3, where t = wire thickness (in this example, this is observed in the radial direction of the fixture) and w = wire width (in this example, this is observed in the tangential direction of the fixture). Therefore, the bending stiffness is strongly related to the wire width. Naturally, in actual embodiments where the wire is obtained by cutting a tube, such a wire has a cross-section that is in the form of a portion of a circular arc when viewed tangentially. Therefore, this equation only shows the actual area moment, but it shows the dependence on the wire width well.

[0090] As a result, the bending stiffness of the force-blocking element 322(k) in the axial position of slot 325 depends on (w1+w2+w3)^3-w3^3, where w1 is the width of the force-blocking sub-element 322(k,1), w2 is the width of the force-blocking sub-element 322(k,2), and w3 is the width of the slot or bridge. However, the bending stiffness of the force-blocking element 322(k) in the axial position of bridge 323 depends on (w1+w2+w3)^3, where w1 is the width of the force-blocking sub-element 322(k,1), w2 is the width of the force-blocking sub-element 322(k,2), and w3 is the width of bridge 323.

[0091] An alternative design to that in Figure 5D is shown in Figure 5F. Instead of being attached to each other by one or more bridges 323, in the embodiment of Figure 5E, two adjacent force-blocking sub-elements 522(k,1) and 522(k,2) are separated by one or more spacer elements 327. The consecutive spacer elements 327 are alternately attached to one of the two force-blocking sub-elements 322(k,1) and 322(k,2), and may only contact the other. In this case as well, slots 325 exist between the consecutive spacer elements 327.

[0092] In the embodiment of Figure 5F, similar to the embodiment of Figure 5E, the bending stiffness of the force-blocking element 322(k) at the axial position of the slot 325 depends on w1^3 + w2^3, where w1 is the width of the force-blocking sub-element 322(k,1) and w2 is the width of the force-blocking sub-element 322(k,2). However, the bending stiffness of the force-blocking element 322(k) at the axial position of the spacer element 327 attached to the force-blocking sub-element 322(k,1) or 322(k,2) depends on w2^3 + (w1 + w3)^3 or w1^3 + (w2 + w3)^3, respectively, where w1 is the width of the force-blocking sub-element 322(k,1), w2 is the width of the force-blocking sub-element 322(k,2), and w3 is the width of the spacer element 327. Therefore, at the axial position of the spacer element 327, the force-blocking element 322(k) in the embodiment of Figure 5F has lower bending stiffness than the force-blocking element 322(k) in Figure 5E.

[0093] As can be seen from the drawings, in the embodiments of Figures 5D, 5E, and 5F, the spacer pairs 320a(i) and 320b(i) are absent. That is, one or both of the spacer pairs 320a(i) and 320b(i) can be omitted, and the force-blocking element 322(k) can be designed to also function as a tangential spacer between adjacent steering wires 16(i). The tangential movement of these force-blocking elements 322(k,1) and 322(k,2) acting as tangential spacers can be blocked relative to the inner and / or outer tubes of the tube in which the force-blocking elements 322(k,1) and 322(k,2) are manufactured, for example, by bending one or more lips 352 from such outer and / or inner tubes within the slot 325. Such lips 352 may have the same width as the slot 325 when viewed tangentially, and are thereby bent into the slot 325 and then clamped within the slot 325. They may be slightly narrower than the slot 325 so as to allow such lip 352 to slide axially inside the slot 325, which may be necessary when variations in the path length inside the body section 309 occur.

[0094] When a device with a flexible shaft is developed without a helical design, it is observed that the spacing elements cannot be force-blocking elements 322(k) and should be individual parts mounted (welded or secured using click / flexible lips) between the two steering wires 16(i). As a result, there are many individual spacing elements (which requires a lot of cutting and assembly time and a risk of loosening during device failure during manufacturing or use). In flexible devices, these elements must be smaller than the shackle distance (distance between hinges) to maintain the flexibility of the device. To reduce the number of loose parts, it is possible to connect these spacing elements with elastic hinges / connectors. Alternatively, openings can be formed in the elements, which are connected to an uppermost layer that holds the element in place but allows axial movement. However, the movement compensation required due to the length deviation introduced by the bending of the shaft is relatively large, and therefore these openings must be larger than the element itself.

[0095] This will be further explained with reference to Figures 5G and 5H. Figure 5G shows a prior art steerable tube as known from International Publication No. 2009 / 098244. The figure shows a tube 500 having a distal end (left) and a proximal end (right). The tube has a plurality of steering wires 502(i) that are cut from the tube 500 and extend from the proximal end to the distal end. At the proximal end, each steering wire 502(i) is attached to the proximal ring 508p by a flexible steering wire portion 504(i). At the distal end, each steering wire 502(i) is attached to the distal ring 508d by a flexible steering wire portion 506(i). Adjacent steering wires 502(i) are separated by spacer elements having a distal spacer element portion 510d, a central spacer element portion 510m, and a proximal spacer element portion 510p. The distal and proximal spacer element portions 510d and 510p are attached to the distal ring 508d and the proximal ring 508p, respectively. The central spacer element portion 510m is flexure-resistant, meaning it cannot be bent or can hardly be bent. Both the distal and proximal spacer element portions 510d and 510p have a wavy pattern.

[0096] The conventional tubes in Figure 5G cannot be used in fixtures having a flexible central section that is to be guided through a winding path. Firstly, the central spacer element portions 510m are flexure-resistant and therefore not designed to bend. Secondly, the central spacer element portions 510m are linear. As a result, even if they were flexible, bending of the central section would result in different central spacer element portions 510m having portions with different path lengths in the central section. Some would need to extend within the flexible distal end and / or flexible proximal end, while others would occupy less path length than is available within the central section. These different path length variations on different sides of the tube when bending need to be compensated for at the flexible distal end and / or flexible proximal end. International Publication No. 2009 / 098244 does not address this.

[0097] In one embodiment, the present invention enables the implementation of spacers between adjacent steering wires 16(i) as uninterrupted wires in an instrument having a flexible body section to be guided through a winding path, for example, through blood vessels or intestines in the (human) body. As described above, by making the steering wires 16(i) and the uninterrupted spacer wires between them spiral, variations in the path length of the body section can be compensated for. Theoretically, at least 360 degrees of spiral are required to compensate for the length differences necessary to bend a passive shaft having a continuous radius along its entire length. Controlling the degree of spiral can be used to control the bending characteristics of the instrument.

[0098] Preferably, the helix measured between the distal and proximal ends is a multiple of 360 degrees, or at least a multiple of 180 degrees if only compensation for the difference in length in one plane is desired.

[0099] Figure 5H shows the same implementation as in Figure 5E, but with "s" added to all reference numbers related to the force-sheltering elements. They are no longer attached at both ends to the inner and / or outer tubes of the tube shown in Figure 5H. Note that they can still be attached to such inner and / or outer tubes, but only at one end. Therefore, they no longer function as force-sheltering elements and function only as continuous spacer wires 322s(k) between adjacent steering wires 16(i). Such uninterrupted spacer wires 322(k) can be divided into two or more spacer subwires 322s(k,1), 322s(k,2), separated by one or more slots 325s and attached by one or more bridges 323s, as shown in Figure 5H. Naturally, other implementations are also possible, such as those shown in Figure 5F.

[0100] It should be noted that such spacer wires 322s(k) may also be applied between elements other than the steering wire 16(i). That is, such spacer wires 322s(k) may be applied between a first part of tube 306 and a second part of tube 306. The first part may be the steering wire 16(i), but may be a control wire manufactured from tube 306 by a suitable cutting (or other material removal) pattern and configured to control a function of the device of which tube 306 is part, such as a locking / unlocking function or any other function as described in detail in the applicant's International Publication Brochure No. 2023 / 287289.

[0101] In Figure 5H or an alternative implementation therein, the actual bending of the body section may still result in several different path lengths for the spacer wire 322s(k) within its body section 309. This can be compensated for by providing axial flexibility to the spacer wire 322s(k) at least one of the distal end, i.e., the flexible tip section 301, and the proximal end, i.e., the flexible portion 203. This can be implemented by providing a spacer wire 322s(k) having a wavy pattern at at least one of the distal and proximal ends, as shown in Figure 5G. Alternatively, other path length compensation mechanisms may be used at the distal and / or proximal ends, as described in detail in the applicant's International Publication No. 2022260518A1 brochure.

[0102] The embodiment shown in Figure 5H may be defined as follows: The steerable tube (312) includes a distal flexible tip section (301), a bendable body section (309) proximal to the flexible tip section (301), one or more steering wires (16(i)) configured to bend the flexible tip section (301) and spiraling in the circumferential direction of the steerable device in at least a portion of the flexible body section (309), and one or more spacer wires (322s(k)) providing a tangential spacer function between a first portion of the tube (312) and a second portion of the tube (312), the one or more spacer wires (322s(k)) extending at least throughout the entire bendable body section (309) and spiraling within the flexible body section (309) like the one or more steering wires (16(i)).

[0103] Embodiments in Figures 5A, 5B, 5C, 5D, 6, and 7 are based on continuously winding all steering wires spirally around the intermediate pipe 312 for 180 degrees positive integer turns. In alternative embodiments, a separate system, such as that shown in Figure 4, may be used, in which case the main section is divided into sub-main section sections, and the 180-degree spiral winding is applied to only some of the sub-main section sections, while the other sub-main section includes linear steering wires extending parallel to each other and to the central axis. In yet another embodiment, if there are specific requirements regarding the plane to which the tip section should be deflected, for example, the total amount of spirals around the intermediate pipe 312 may differ from a positive integer multiple of 180 degrees. Thus, path length compensation may not be perfect, but can be compensated by implementing an additional Bowden cable configuration for both the steering wire 16(i) and the force-sheltering element 322(k) at the proximal end of the device, for example, as schematically shown in box 355 in Figure 5C. For example, one of the Boden cable configurations shown and described in International Publication No. 2022260518A1 can be applied.

[0104] As described above, in the embodiments of Figures 5A, 5B, 5C, 5D, 6, and 7, all longitudinal force blocking elements 322(k) are attached at their distal ends to at least one of the inner tube 330 or outer tube 340 at the distal end of the main body section 309, and at their proximal ends to at least one of the inner tube 330 or outer tube 340 at the proximal end of the main body section 309. Thus, the axial load on the main body section of the instrument caused by operating the steering wire 16(i) to bend the main body section and / or deflect the tip portion 358 is carried by these longitudinal force blocking elements 322(k). As a result, the pushing and pulling forces exerted by the steering wire 16(i) to deflect the tip portion 358 are blocked from the main body portion 356. As a result, these pushing and pulling forces in the steering wire 16(i) are far more balanced than in conventional setups, and consequently, when operating the tip portion 358 of the invasive instrument, the helical steering wire 16(i) is found to reduce undesirable movement of the body portion 356 due to the resulting torque load.

[0105] In practice, depending on the design and curvature of the curved channel into which the invasive instrument is inserted, complete path length compensation may not be achieved, meaning that offset errors may remain. If only a short length of the flexible body section of the instrument is bent, and this length is shorter than one helical period of 180 degrees, a small difference in length offset occurs between the steering wire 16(i) and the longitudinal force blocking element 322(k). As a result, the shaft of the instrument may be twisted by muscle force.

[0106] Such offset errors in path length compensation become larger in the discrete systems described above. The lengths of the sub-body sections of these separate systems where the steering wire extends linearly, the lengths between sub-body sections where both the steering wire and longitudinal force-shelving elements are spirally bent at 180 degrees, and the maximum angle at which these sub-body sections can bend determine the maximum residual offset error of the instrument. The more sub-body sections where the steering wire and longitudinal force-shelving elements are spirally bent at 180 degrees, and the shorter the sub-body sections where the steering wire and longitudinal force-shelving elements extend linearly, the smaller the possible residual error.

[0107] Even in devices where the steering wire 16(i) and longitudinal force blocking element 322(k) are continuously spiraled around the intermediate pipe 312 along the entire body section 309, as shown in Figures 5A, 5B, 5C, 5D, 6, and 7, a small error may occur in the path length compensation when the body section bends along only a portion of its total length, especially when the bent portion is shorter than the length of the 180-degree spiral portion. This effect decreases as the pitch of the spiral steering wire 16(i) and longitudinal force blocking element 322(k) decreases.

[0108] To avoid or at least minimize such offset errors and the resulting massling effect in the main body section of the instrument, an additional “coil pipe” or Bowden cable section may be applied proximal to the proximal end of the main body section, as schematically shown in Figure 5C by reference no. 355. In Figure 5C, the Bowden cable section 355 is depicted inside the steering section 354, but alternatively, it may be located between the proximal end of the main body section 356 and the steering section 354. Examples of such coil pipes or Bowden cable sections, entirely manufactured by (laser) cutting components from a tube, are disclosed in International Publication No. 2022260518A1. Since the coil pipes or Bowden cable sections absorb to some extent the length of the steering wire within the main body section without bending the flexible tip section and without bending the proximal end of the instrument, they all compensate for the path length difference within the main body section that would result from bending the main body section. All embodiments described in International Publication No. 2022260518A1 can be used as additional path length compensation mechanisms for both the steering wire 16(i) and the force-sheltering element 322(k) in embodiments of the present invention. Since the possible remaining offset errors in these embodiments are relatively small, these known coil pipe or Bowden cable configurations do not need to be large and may require only relatively small space.

[0109] It has been observed that an invasive instrument with path length compensation, as described with reference to Figures 5A, 5B, 5C, 5D, 6, and 7, can be easily manufactured with only three tubes. This embodiment is simpler than the embodiment disclosed in International Publication No. 2022260518A1 brochure and avoids the possible bending force of a flexible shaft for controlling the instrument at the proximal end of the instrument, as in that patent application.

[0110] Embodiments in Figures 5A, 5B, 5C, 5D, 6, and 7 show three tubes, all of which are fabricated by creating appropriate cutting patterns for them. However, the present invention is not limited to applications having three tubes. For example, the device may have more tubes. The steering wire 16(i) may have separate parts that are connected or attached to each other, fabricated from the tubular material of two or more such tubes, as described in International Publication No. 2017213491. Furthermore, the device may have other longitudinal elements fabricated from the tubular material and configured to lock or unlock the curvature of a part of the body, as described in International Publication No. 2023287289, for example, to perform another function other than steering the tip or blocking a force.

[0111] While the invasive instrument is shown to have one flexible tip, the present invention is not limited thereto. That is, the invasive instrument may have multiple flexible tip portions.

[0112] All tubes 330, 312, and 340 may have one of the following cross-sections: circular, oval, elliptical, or rectangular.

[0113] All tubes 330, 312, and 340 are made of the following combination of materials, at least partially: Biocompatible polymer materials including polyurethane, polyethylene, or polypropylene, stainless steel, Cobalt-chromium, Shape memory alloys such as Nitinol (registered trademark), plastic, polymer, Composite material, or Other curing materials It can be made from at least one of the following.

[0114] In one embodiment, the components of the tube, including one or more steering wires 16(i) and one or more longitudinal force-blocking elements 322(k), are derived from a material removal technique applied to the wall of at least one tube 312 to produce a suitable cutting pattern, including at least one of photochemical etching, deep drawing, cutting techniques, laser cutting, or water cutting. The material removal means may be a laser beam or waterjet cutting beam that melts and vaporizes the material, and the beam may have a width of 0.01 to 2.00 mm, more typically 0.015 to 0.04 mm in this application.

[0115] The wall thickness of the pipe depends on its application. For medical applications, the wall thickness may be in the range of 0.03 to 2.0 mm, preferably 0.03 to 1.0 mm, more preferably 0.05 to 0.5 mm, and most preferably 0.08 to 0.4 mm. The diameter of the pipe depends on its application. For medical applications, the diameter may be in the range of 0.5 to 20 mm, preferably 0.5 to 10 mm, and more preferably 0.5 to 6 mm. The radial clearance between adjacent pipes may be in the range of 0.01 to 0.3 mm.

[0116] The features of the present invention, as described with reference to the drawings above, can be summarized as follows.

[0117] The present invention relates to a steering device having a distal flexible tip portion (358) and a proximal bendable body portion (356) from the tip portion (358), wherein the steering device includes at least one tube (312), at least one inner tube (330) inside the at least one tube (312) or at least one outer tube (340) outside the at least one tube (312), and one or more steering wires (16(i)) inside the at least one tube (312), wherein the at least one tube (312) includes a flexible tip section (301) within the flexible tip portion (358) and a bendable body The steering device includes a flexible body section (309) within a portion (356), one or more steering wires (16(i)) spiral in the circumferential direction of the steering device in at least a portion of the flexible body section (309), the steering device also includes one or more longitudinal force-blocking elements (322(k)) within at least one tube (312), the longitudinal force-blocking elements (322(k)) are arranged parallel to the one or more steering wires (16(i)) within the flexible body section (309), the one or more longitudinal force-blocking elements (322(k)) have a distal end and a proximal end, and the following features: If the steering device includes an outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) at the distal end of the main section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) at the proximal end of the main section (309), or If the steering device includes an inner tube (330), the distal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) at the distal end of the main section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) at the proximal end of the main section (309), or If the steering device includes an inner tube (330) and an outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) at the distal end of the main section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) at the proximal end of the main section (309). One of the following applies.

[0118] One or more steering wires (16(i)) are helically routed 180 degrees circumferentially around the steering device in at least one portion of the flexible body section (309), which may provide path length compensation caused by bending in at least one portion of the flexible body section (309).

[0119] One or more steering wires (16(i)) are helical 180 degrees circumferentially of the steering device over a certain number of times in an equal number of portions of the flexible body section (309), and may provide path length compensation caused by one or more bends in that number of portions of the flexible body section (309).

[0120] One or more steering wires (16(i)) may be continuously spiral along the entire flexible body section (309).

[0121] In such a steerable device, a plurality of steering wires (16(i)) may be positioned equidistant from each other parallel to the tangential direction of at least one pipe (312), and at least one pipe may have a plurality of longitudinal force blocking elements (322(k)), and at least one longitudinal force blocking element (322(k)) may be positioned between two adjacent steering wires (16(i), 16(i+1)).

[0122] Each longitudinal force blocking element (322(k)) may be attached to a spacer (318(i)) configured to maintain two adjacent steering wires (16(i)) at a desired tangential distance, and If the steering device includes an outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) via the attachment portion of the spacer (318(i)) to the outer tube (340), or If the steering device includes an inner tube (330), the distal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) via the attachment portion of the spacer (318(i)) to the inner tube (330), or If the steering device includes an inner tube (330) and an outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) via a spacer (318(i)) attachment to at least one of the inner tube (330) or the outer tube (340).

[0123] There may be one longitudinal force blocking element (322(k)) positioned between and equidistant from two adjacent steering wires (16(i), 16(i+1)).

[0124] A pair of flexible spacers (320a(i), 320b(i)) may be provided between two adjacent steering wires (16(i), 16(i+1)) proximal to a spacer (318(i)), the first of the pair of flexible spacers (320a(i), 320b(i)) being located between a single longitudinal force blocking element (322(k)) and the first of two adjacent steering wires (16(i), 16(i+1)), and the second of the pair of flexible spacers (320a(i), 320b(i)) being located between a single longitudinal force blocking element (322(k)) and the second of two adjacent steering wires (16(i), 16(i+1)).

[0125] At least one tube (312) may include a ring-shaped end portion (314) at its distal end to which one or more steering wires (16(i)) are attached.

[0126] At least one of the longitudinal force blocking elements (322(k)) may be provided with a through hole (325), and the lip extends from either the inner tube (330) or the outer tube (340) through the through hole (325), and the lip and the through hole (325) are configured to prevent tangential movement of the longitudinal force blocking element (322(k)) relative to the inner tube (330) or the outer tube (340), respectively, but to allow axial movement.

[0127] The tip section of at least one tube (312) may include a spacer (316(i)) between each of two adjacent steering wires (16(i), 16(i+1)), each spacer (316(i)) having a regular waveform pattern such as a block wave or sinusoidal pattern.

[0128] The steering device may have a Bowden cable section (355) proximal to the proximal end of the main section (356) to compensate for the offset of the path length difference of the steering wire (16(i)).

[0129] Hinge structure In other embodiments, the present invention relates to a hinge structure, i.e., the one shown in Figure 7 by reference numeral 360. As an introduction to a detailed description of such a hinge structure, Figure 8, which is a copy of Figure 9 from International Publication No. 2018067004, will be described first.

[0130] Figure 8 shows a hinge structure 402 within the pipe 400. The hinge structure 402 is shown to have two identical hinges 401(1) and 401(2), which are rotated 90 degrees tangentially to the pipe 400. Similar reference numbers without "(1)" or "(2)" refer to the same component of the respective hinges 401(1) and 401(2).

[0131] The hinge 401(1) is fabricated by a cutting pattern of the pipe 400. The cutting pattern defines the distal side, i.e., the left-hand side, and the proximal side, i.e., the right-hand side, of the hinge 401(1). The distal and proximal sides are connected to each other by two identical longitudinal bridges, one of which is indicated by reference numeral 404(1). The other, not visible in Figure 8, is positioned rotated 180 degrees tangentially to the longitudinal bridge 404(1) of the pipe 400. The longitudinal bridge 404(1) is a strip formed in the wall material of the pipe 400 by two parallel longitudinal slits 406(1) and 408(2) extending in the longitudinal direction of the pipe 400. The two parallel longitudinal slits 406(1) and 408(2) have the same length. The longitudinal bridge 404(1) has a center of rotation 426(1).

[0132] The first tangential slit 410(1) extends from the longitudinal slit 406(1) in the first tangential direction of the pipe 400. The first tangential slit 410(1) connects to the longitudinal slit 406(1) at its center. The first tangential slit 410(1) covers a tangential range of less than 180 degrees. The first tangential slit 410(1) is interrupted by the first lip-shaped portion 412(1) distal to the hinge 401(1). The first lip-shaped portion 412(1) extends longitudinally of the pipe 400 at the first opening 414(1) proximal to the hinge 401(1). The first lip-shaped portion 412(1) and the opening 414(1) are separated by a small slit 428(1) such that the outer surface of the first lip-shaped portion 412(1) matches the inner surface of the first opening 414(1) and the first lip-shaped portion 412(1) can move freely inside the first opening 414(1).

[0133] The second tangential slit 418(1) extends from the longitudinal slit 408(1) in a second tangential direction of the pipe 400. The second tangential direction is opposite to the first tangential direction. The second tangential slit 410(1) connects to the longitudinal slit 408(1) at its center. The second tangential slit 418(1) covers a tangential range of less than 180 degrees. The second tangential slit 418(1) is interrupted by the distal lip-shaped portion 420(1) of the hinge 401(1). The lip-shaped portion 420(1) extends longitudinally of the pipe 400 within the proximal opening 422(1) of the hinge 401(1). The lip-shaped portion 420(1) and the opening 422(1) are separated by a small slit 430(1) such that the outer surface of the lip-shaped portion 420(1) matches the inner surface of the opening 422(1), and the lip-shaped portion 420(1) can move freely inside the opening 422(1).

[0134] The lip-shaped portion 412(1) has a first curved side portion extending along a portion of a first circle C1 whose center coincides with the rotation center 426(1) of the longitudinal bridge 404(1). The lip-shaped portion 412(1) has a second curved side portion opposite to the first curved side portion, which extends along a portion of a second circle C2 whose center similarly coincides with the rotation center 426(1) of the longitudinal bridge 404(1).

[0135] The lip-shaped portion 420(1) has a third curved side portion extending along a portion of the first circle C1 and a fourth curved side portion on the opposite side of the third curved side portion, which extends along a portion of the second circle C2.

[0136] The longitudinal bridge 404(1), longitudinal slits 406(1), 408(1), tangential slits 410(1), 418(1), lip-shaped portions 412(1), 420(1), and openings 414(1), 422(1) define a first cutting pattern within the pipe 400. A second cutting pattern identical to the first cutting pattern exists within the pipe 400 at a 180-degree rotational position. Figure 8 shows the end portion of the tangential slit 416(1) of the second cutting pattern corresponding to the tangential slit 418(1) of the first cutting pattern, and the end portion of the tangential slit 424(1) of the second cutting pattern corresponding to the tangential slit 410(1) of the first cutting pattern.

[0137] The tangential slits 416(1) and 424(1) extend tangentially even over lengths shorter than 180 degrees. The tangential slit 410(1) of the first cutting pattern and the tangential slit 416(1) of the second cutting pattern do not coincide at any position, but they overlap tangentially such that a tangentially extending tangential bridge 403(1) is located between them. One end of the tangential bridge 403(1) is attached to the distal side of the hinge 401(1), and the other end is attached to the proximal side of the hinge 401(1). The tangential slit 418(1) of the first cutting pattern and the tangential slit 424(1) of the second cutting pattern do not coincide at any position, but they overlap tangentially such that a tangentially extending tangential bridge 405(1) is located between them. The tangential bridge 405(1) is attached at one end to the distal side of the hinge 401(1) and at the other end to the proximal side of the hinge 401(1).

[0138] The first and second cutting patterns allow the pipe 400 to bend by rotating the distal and proximal sides of the hinge 401(1) in opposite directions within a first plane perpendicular to an imaginary line passing through the rotation center 426(1) of the longitudinal bridge 404(1) and the center of the longitudinal bridge of the second cutting pattern on the opposite side of the pipe 400.

[0139] During use, it may be desirable to rotate the pipe 400 around its central axis 29 to generate torque in the pipe 400. Torsional forces can damage the hinge 401(1) by deformation or rupture of the wall material of the pipe 400. The tangential bridges 403(1) and 405(1) absorb such torsional forces to an extent corresponding to their elasticity, which is determined by the wall material and their dimensions.

[0140] The invisible counterparts of the lip-shaped portions 412(1), 420(1) and the second cutting pattern inside the openings 414(1) and 422(1) prevent relative tangential rotation between the distal and proximal sides of the hinge 401(1) after a certain minimum amount of relative tangential rotation permitted by the slits between the lip-shaped portions 412(1) and 420(1) and the openings 414(1) and 422(1), respectively. In this way, the invisible counterparts of the lip-shaped portions 412(1), 420(1) and the second cutting pattern further counteract the potential damaging effect of torsional forces.

[0141] Figure 8 shows some components of hinge 401(2), which is identical to hinge 401(1), rotated 90 degrees relative to hinge 401(1). Tube 400 has a distal portion located distal to hinge 401(2) and a proximal portion located proximal to hinge 401(2). Hinge 401(2) also has two opposing longitudinal bridges, each with its own center. Thus, hinge 401(2) allows rotation of these distal and proximal portions relative to each other in a second plane perpendicular to a virtual line passing through the two centers of these two longitudinal bridges. The second plane is perpendicular to the first plane described above, allowing the hinge structure 402, including hinges 401(1) and 401(2), to bend in three dimensions. The hinge structure 402 shown may be repeated multiple times within the tube 400 so that the tube 400 can bend in three dimensions along a longer length of the tube 400.

[0142] The lip-shaped portions 412(1), 420(1), 412(2), and 420(2) should have a specific size, particularly in the longitudinal direction, so that they are effective and not easily damaged by torsional forces. Therefore, they may limit further miniaturization of the tube 400. This aspect of the present invention addresses this problem as described with reference to Figures 9 to 12C.

[0143] In Figure 9, which shows a side view of the first hinge 407(1) of the hinge structure 360 ​​of the present invention, the same reference numerals used in the previous figures are used to refer to the same components. It is observed that this hinge structure can be applied not only to the devices shown in Figures 1A to 7, but also to any flexible tube. Such a flexible tube may be part of any type of flexible invasive instrument, for example, for endoscopic applications. Such a flexible invasive instrument may have one or more flexible ends that can be bent by a suitable steering section 354 at the proximal end. The steering wire may be a strip resulting from creating a suitable cutting pattern in one or more coaxial tubes, or it may be a cable. They may be linear or spiral within the instrument.

[0144] In the pipe 400 in Figure 9 (see also the three-dimensional view in Figure 10), the tangential slit 410(1) includes tangential slit portions 410a(1) and 410b(1), and the tangential slit 418(1) includes tangential slit portions 418a(1) and 418b(1). The tangential slit portions 410a(1) and 410b(1) are connected to each other and have their respective ends 409(1) and 419(1). The tangential slit portions 410a(1) and 410b(1) extend from end 409(1) to end 419(1) and partially surround the pipe 400 in the tangential direction E. In one embodiment, the tangential slit portion 410a(1) is tapered toward the end portion 409(1), and the tangential slit portion 410b(1) is tapered toward the end portion 419(1). However, the tangential slit portions 410a(1) and 410b(1) may have a single width along their length, which may be the same for both.

[0145] The tangential slit portions 418a(1) and 418b(1) are connected to each other and have their respective ends 411(1) and 413(1). The tangential slit portions 418a(1) and 418b(1) extend from end 411(1) to end 413(1) and partially surround the pipe in the tangential direction F. In one embodiment, the tangential slit portion 418a(1) is tapered toward end 411(1), and the tangential slit portion 418b(1) is tapered toward end 413(1). The tapering of the tangential slit portion 410a(1) may be equal to the tapering of the tangential slit portion 418a(1), and the tapering of the tangential slit portion 410b(1) may be equal to the tapering of the tangential slit portion 418b(1). Furthermore, the tangential slit portions 418a(1) and 418b(1) can have a single width along their length, which may be the same for both and may be the same as that of the tangential slit portions 410a(1) and 410b(1).

[0146] The tangential directions E and F are opposite directions. Ends 409(1) and 411(1) are located on the same circumference in a plane perpendicular to the central axis 29 extending in the longitudinal direction of the pipe 400. Ends 409(1) and 411(1) are positioned opposite each other.

[0147] End 409(1) coincides with the center of the longitudinal slit 406(1), and end 411(1) coincides with the center of the longitudinal slit 408(1), both extending longitudinally along the pipe 400 so that they define the longitudinal side of the longitudinal bridge 404(1). Ends 409(1) and 411(1) may coincide with other portions of the longitudinal slits 406(1) and 408(1), respectively.

[0148] As shown, both longitudinal slits 406(1) and 408(1) can be curved in opposite directions such that the longitudinal bridge 404(1) has a minimum width t at a specific location that may be at the center of the entire length of the longitudinal bridge 404(1). The width t may have a value of 0.05 to 0.3 mm. The longitudinal slit 406(1) has a length LB1 which may have a value of 0.3 to 4 mm. The longitudinal slit 408(1) has a length LB2 which may have a value of 0.3 to 4 mm. Length LB1 may be equal to length LB2. The shape of the longitudinal slit 406(1) may coincide with a portion of a first circle CB1 having a first radius of 0.5 to 10 mm. The shape of the longitudinal slit 408(1) may coincide with a portion of a second circle CB2 having a second radius of 0.5 to 10 mm. The radius of the second circle CB2 may be the same as the radius of the first circle CB1. The values ​​provided herein for width t, lengths LB1 and LB2, and radii of CB1 and CB2 may be applicable to pipe fixtures having radii of 1 to 15 mm and wall thicknesses of 0.08 to 2 mm.

[0149] Therefore, the longitudinal bridge 404(1) has a center of rotation 426(1) that is better defined at the center where the portion of the tube 400 located on the longitudinally opposite side of the bridge 404(1) can bend, compared to the case where the longitudinal bridge 404(1) has an equal width along its length, and thus provides more precise movement to the instrument.

[0150] In one embodiment, the tangential directions E and F lie in a plane perpendicular to the central axis 29 of the pipe 400. However, direction E may form an angle with such a plane. The tangential direction F may also form an angle with such a plane. These angles may be -20° to +20° or -10° to +10° degrees, more preferably -8° to +8° degrees. They may have the same value.

[0151] The tangential slit portions 410a(1) and 410b(1) are located in longitudinally shifted positions and are connected to both ends of a longitudinal channel 425(1) that extends longitudinally from the device 400 to form a tangential shoulder structure. The side walls of the longitudinal channel 425(1) are defined by walls 442(1) and 440(1) that extend longitudinally from the device between the tangential slit portions 410a(1) and 410b(1). In one embodiment, the walls 442(1) and 440(1) are linear. However, they may have a curvature that coincides with a portion of a circle having the rotation center 426(1) as its center in order to align the movement of the hinge during rotation with the rotation center 426(1). At the non-bent positions on the distal and proximal sides of the hinge 407(1), the walls 442(1) and 440(1) partially overlap as seen tangentially from the device. The amount of overlap can be between 0.05 and 3 mm.

[0152] The tangential slit portions 418a(1) and 418b(1) are located in longitudinally shifted positions and connect to both ends of a longitudinal channel 427(1) that extends longitudinally from the device 400 to form a tangential shoulder structure. The side walls of the longitudinal channel 427(1) are defined by walls 446(1) and 444(1) that extend longitudinally from the device between the tangential slit portions 418a(1) and 418b(1). In one embodiment, the walls 446(1) and 444(1) are linear. However, they may have curvature that coincides with a portion of a circle having the rotation center 426(1) as its center in order to align the movement of the hinge during rotation with the rotation center 426(1). At the distal and proximal non-bent positions of the hinge, the walls 446(1) and 444(1) partially overlap as seen tangentially from the device. The amount of overlap can be between 0.05 and 3 mm.

[0153] During use, the instrument 400 can be rotated tangentially, for example, by applying a rotational force to the proximal end of the instrument 400. The instrument can then be positioned inside a channel, such as the intestines, blood vessels, or esophagus of an organism. Rotating the instrument inside such a channel can create friction between the channel wall and the instrument 400, resulting in a torsional force on the instrument. The hinge structure shown in Figures 9 and 10 allows wall 442(1) to abut against wall 440(1) and wall 446(1) to abut against wall 444(1) during rotation, thereby limiting (or preventing) the possible rotational difference between the distal and proximal sides of the hinge 407(1) shown in these figures to a specific maximum value, thus limiting the torsional response loss. Thus, the hinge, by walls 442(1), 440(1), 446(1), and 444(1), provides additional torsional stiffness.

[0154] Figure 10 shows a 3D view of pipe 400 so that the inside of pipe 400 can also be seen. Thus, further details of the first hinge 407(1) shown in Figure 9 can be seen in Figure 10. Apart from the first hinge shown in Figure 9, Figure 10 shows a second hinge 407(2) which is identical to the one shown in Figure 9, and the second hinge is rotated 90 degrees tangentially so that the entire hinge structure can be bent in all directions, as will be obvious to those skilled in the art. In Figure 10, the individual features of the first hinge 407(1) shown in Figure 9 are shown with the same reference numerals. The features of the second hinge 407(2) shown in Figure 10 are shown with the same reference numerals, but with the indicator "(2)" instead of "(1)".

[0155] Here, the features of the first hinge 407(1), which is not (completely) visible in Figure 9, will be described in detail. This description will not be repeated for the second hinge 407(2), but will be identical except that "(1)" is changed to "(2)". As shown in Figure 10, the first hinge 407(1) has tangential slit portions 424a(1), 424b(1) and tangential slit portions 416a(1), 416b(1). The tangential slit portions 424a(1), 424b(1) have ends 423(1) and 415(1). The tangential slit portions 424a(1), 424b(1) extend from end 423(1) to end 415(1) and partially surround the pipe in the tangential direction H (see Figure 9). The tangential slit portions 416a(1) and 416b(1) have ends 421(1) and 417(1). The tangential slit portions 416a(1) and 416b(1) extend from end 421(1) to end 417(1) and partially surround the pipe in the tangential direction G (see Figure 9). The tangential direction H and the tangential direction G are opposite directions. Ends 423(1) and 421(1) are located in the same plane perpendicular to the aforementioned central axis 29 where ends 409(1) and 411(1) are located. Ends 423(1) and 421(1) are positioned opposite each other.

[0156] End 423(1) coincides with the center of the longitudinal slit 452(1), and end 421(1) coincides with the center of the longitudinal slit 448(1). Both of these extend longitudinally along the pipe 400 so as to define the longitudinal side surface of the longitudinal bridge 450(1).

[0157] Like the longitudinal slits 406(1) and 408(1), the longitudinal slits 452(1) and 448(1) can be curved in opposite directions such that the longitudinal bridge 450(1) has a minimum width t at a specific position that may be in the center of the entire length of the longitudinal bridge 450(1). The width t may have a value of 0.05 to 0.3 mm. Slit 452(1) has a length LB3 which may have a value of 0.3 to 4 mm. Slit 448(1) has a length LB4 which may have a value of 0.3 to 4 mm. Length LB3 may be equal to length LB4. Furthermore, lengths LB1, LB2, LB3, and LB4 may all be equal. The shape of slit 452(1) may coincide with a portion of a third circle CB3 having a third radius of 0.5 to 10 mm. The shape of slit 448(1) may coincide with a portion of a fourth circle CB4 having a fourth radius of 0.5 to 10 mm. The radius of the fourth circle CB4 may be equal to the radius of the third circle CB3. Furthermore, the radii of all circles CB1, CB2, CB3 and CB4 may be equal. The values ​​provided herein for width t, length LB3 and LB4, and radius of CB3 and CB4 may be applicable to pipe fixtures having radii from 1 to 15 mm and wall thicknesses from 0.08 to 2 mm.

[0158] Therefore, the longitudinal bridge 450(1) has a better center of rotation 458(1) at the center where the portion of the tube 400 located on the longitudinally opposite side of the bridge 450(1) can bend, compared to the case where the longitudinal bridge 450(1) has an equal width along its entire length, providing the instrument with higher movement accuracy.

[0159] The tangential slit portions 424a(1) and 424b(1) are located in longitudinally shifted positions and are connected to both ends of a longitudinal channel 429(1) that extends longitudinally from the fixture 400 to form a tangential shoulder structure. The side walls of the longitudinal channel 429(1) are defined by walls 454(1) and 456(1) that extend longitudinally from the fixture between the tangential slit portions 424a(1) and 424b(1). In one embodiment, the walls 454(1) and 456(1) are linear. However, they may have a curvature that coincides with a portion of a circle having the rotation center 458(1) of the longitudinal bridge 450(1) as its center, so as to align the movement of the hinge during bending with the rotation center 458(1). At the non-bent positions of the distal and proximal hinge 407(1), the walls 454(1) and 456(1) partially overlap, as seen in the tangential direction of the device. The amount of overlap may be 0.05 to 3 mm.

[0160] The tangential slit portions 416a(1) and 416b(1) are located in longitudinally shifted positions and connect to both ends of a longitudinal channel 431(1) that extends longitudinally from the fixture 400 to form a tangential shoulder structure. The side walls of the longitudinal channel 431(1) are defined by walls 462(1) and 464(1) that extend longitudinally from the fixture between the tangential slit portions 416a(1) and 416b(1). In one embodiment, the walls 462(1) and 464(1) are linear. However, they may have a curvature that coincides with a portion of a circle having the rotation center 458(1) as its center in order to align the movement of the hinge during bending with the rotation center 458(1). In the non-bending position of the two opposing sides of the hinge, the walls 462(1) and 464(1) partially overlap as seen tangentially from the fixture. The amount of overlap can be between 0.05 and 3 mm.

[0161] As described above, during use, the instrument 400 can be rotated tangentially, for example, by providing a rotational force to the proximal end of the instrument. The instrument can then be positioned inside a channel, such as the intestines, blood vessels, or esophagus of an organism. Rotating the instrument inside such a channel can cause friction between the channel wall and the instrument, resulting in a torsional force on the instrument. The hinge structure shown in Figures 9 and 10 can better cope with the increased torsional force because, during rotation, wall 454(1) can abut against wall 456(1) and wall 462(1) can abut against wall 464(1), and limits (or prevents) any possible rotational difference between the distal and proximal sides of the hinge shown in these figures to a specific maximum value. Thus, the hinge structure shown in these figures provides additional torsional rigidity through walls 454(1), 456(1), 462(1), and 464(1).

[0162] In one embodiment, the tangential directions G and H lie in the aforementioned plane perpendicular to the central axis of the pipe 400. However, direction G may form an angle with such a plane. The tangential direction H may also form an angle with such a plane. These angles may be between -10° and +10° degrees, more preferably between -8° and +8° degrees. They may have the same value.

[0163] The longitudinal bridges 404(1) and 450(1) are preferably located on the tube 400 rotated 180 degrees relative to each other on the circumference, thereby allowing the tube 400 to bend around imaginary lines passing through the centers of rotation 426(1) and 458(1).

[0164] As shown in Figures 9 and 10, the tangential slit portions 410b(1) and 416b(1) overlap circumferentially, that is, a portion of the tangential slit portion 410b(1) is adjacent to a portion of the tangential slit portion 416b(1) when viewed longitudinally, but these portions do not engage with each other. The tangential bridge 403(1) is located between these portions of the tangential slit portions 410b(1) and 416b(1). The ends of the tangential bridge 403(1) are attached to the distal and proximal sides of the hinge 407(1), respectively. In one embodiment, the tangential bridge 403(1) has a constant width BW(1) (when viewed longitudinally of the device). This width may be 0.05 to 0.3 mm. The tangential bridge 403(1) may have a length equal to 20-45% of the circumference of the pipe.

[0165] As shown in Figure 10, the tangential slit portion 418b(1) and the tangential slit portion 424b(1) overlap in the circumferential direction, that is, a portion of the tangential slit portion 418b(1) is located adjacent to a portion of the tangential slit portion 424b(1) when viewed longitudinally, but these portions do not engage with each other. The tangential bridge 405(1) is located between these portions of the tangential slit portion 418b(1) and the tangential slit portion 424b(1). The ends of the tangential bridge 405(1) are attached to the distal and proximal sides of the hinge 407(1), respectively. In one embodiment, the tangential bridge 405(1) has a constant width BW(2) (when viewed longitudinally of the device). This width can be 0.05 to 0.3 mm and may be the same as the width of the tangential bridge 403(1). The tangential bridge 405(1) may have a length equal to 20-45% of the circumference of the pipe. The lengths of the tangential bridges 403(1) and 405(1) may be equal.

[0166] Although longitudinal bridges 404(j) and 450(j) are shown here as straight bridges, other forms including S-shaped, Z-shaped, or block wave shapes may also be used, as shown in, for example, International Publication No. 2018067004.

[0167] Figure 11 shows one embodiment having three adjacent hinges. Four or more may exist. They are identical, and their features are indicated by indicators (1), (2), and (3), respectively. They are all located in the same tangential direction, making the entire hinge structure flexible only in a single plane, namely a plane perpendicular to the imaginary lines passing through the rotation centers 426(j) and 458(j) (j=1, 2, ...J).

[0168] In embodiments shown with reference to Figures 9 to 11, the channels defined by the side walls 442(j) / 440(j), 446(j) / 444(j), 454(j) / 456(j), and 462(j) / 464(j) have a specific width, defined, for example, by the width of the laser beam used to create all the slit patterns within the tube 400 when a laser is used. The width of these channels defines the maximum tangential play between adjacent sides of each hinge when the hinges rotate tangentially relative to each other. To reduce such play, it is desirable to keep this width as small as possible. Figures 12A, 12B, and 12C show methods for reducing this width of these channels.

[0169] Figure 12A is identical to Figure 9 except as follows: When a slit pattern is produced in the pipe 400, the opposing side walls 442(1) and 440(1) are still attached to each other by the crushing element 480(1). Similarly, when a slit pattern is produced in the pipe 400, the opposing side walls 446(1) and 444(1) are still attached to each other by the crushing element 482(1). Figure 12B shows an example of an enlarged crushing element 482(1).

[0170] For example, a manufacturing process that creates a slit pattern by laser cutting provides a crushing element 482(1) having a wide portion 484(1) and a narrow portion 488(1). Here, the wide portion 484(1) is attached to the side wall 446(1), the narrow portion 488(1) is attached to the side wall 444(1), and the wide portion 484(1) is attached to the narrow portion 488(1). The first reason for manufacturing such a crushing element 482(1) is to keep the different opposing portions of the tubular element 400 separated by the slit still attached to each other, which makes the operability of the tube 400 much easier, for example, when it has to be inserted into another tube or another tube has to be inserted into it. However, the second reason is that such a crushing element can be used to reduce play between such opposing portions.

[0171] If the side walls 446(1) and 444(1) are manufactured, for example, by a laser beam cutting a longitudinal channel 427(1) between them, they have a minimum distance w1 resulting from the width of the laser beam. If a crushing element 482(1) as described herein is not applied, this minimum distance w1 defines the play between the side walls 446(1) and 444(1) when both sides of the hinge rotate tangentially relative to each other.

[0172] In use, when the hinge is forced to bend such that two opposing sides of the hinge rotate about the centers of rotation 426(1), 458(1), the opposing side walls 446(1), 444(1) are forced to move in opposite longitudinal directions. As shown in Figure 12B, side wall 446(1) can be forced to move in a first longitudinal direction by force F2, and side wall 444(1) can be forced to move in a second, opposite longitudinal direction by force F1. The crushing element 482(1) is such that when these forces F1 and F2 exceed a specific threshold force, the small-diameter portion 488(1) breaks, but the wide portion 484(1) remains intact. The material of the hinge to which the wide portion 484(1) is attached is designed to only elastically deform and not plastically deform, and the material of the hinge to which the small-diameter portion 488(1) is attached is also designed to only elastically deform and not plastically deform by forces F1 and F2. The wide portion 484(1) can also, by these forces, deform only elastically and not plastically, although this is not essential.

[0173] Assuming that the small-diameter portion 488(1) has a length w2 < w1 in the tangential direction of the instrument, after the small-diameter portion 488(1) is crushed, the wide portion 484(1) can be separated from the side wall 444(1) and pushed in the tangential direction of the tube 400 towards the side wall 444(1) along a distance of up to w2. This reduces the maximum play between the side walls 446(1), 444(1) to w2.

[0174] A method of manufacturing such a crushing element and an example of its shape are disclosed and described in the applicant's International Publication No. WO 2016 / 089202 pamphlet. The manufacture of a crushing element that can be used to reduce the play between adjacent components of a tube separated by a slit can be found in the applicant's International Publication No. WO 2020 / 080938 pamphlet. Play-reducing crushing elements as disclosed in these applications can also be used.

[0175] The detailed description provided herein for the crushing element 482(1) is equally applicable to the crushing element 480(1). Furthermore, similar or identical play-reducing crushing elements can be applied between all opposing side walls 454(j) / 456(j) and 462(j) / 464(j).

[0176] Figure 12C shows an alternative crushing element 490(1) to the crushing element 482(1) in Figure 12B.

[0177] As shown in Figure 12C, the side wall 444(1) is divided into two parts: a first side wall portion 444a(1) located in the tangential extension of the tangential slit 418a(1), and a second side wall portion 444b(1) defining the side wall of the longitudinal channel 427(1) between the tangential slits 418a(1) and 418b(1). The tangential distance between the second side wall portion 444b(1) and the side wall 446(1) is denoted by width w1. Width w1 depends on the manufacturing method used, for example, the size of the laser beam. The tangential distance between the second side wall portion 444a(1) and the side wall 446(1) is denoted by width w3, where w3 may be as small as approximately 0 mm. Width w1 > w3. During the manufacturing of the pipe 400, the small crushing or melting elements 490(1) are held in the transition region between the first sidewall portion 444a(1) and the second sidewall portion 444b(1).

[0178] When element 490(1) is implemented as a crushing element, it is crushed by bending hinge 407(1) with a specific predetermined bending force. In this sense, when the bending force schematically shown in F1 and F2 exceeds a certain threshold force, the reaction force caused by the bending force within the crushing element causes the crushing element 490(1) to crush, while the material of the sidewall to which they are attached remains intact, as this material can only deform elastically and not plastically. Crushing can also be caused by fatigue, i.e., by bending hinge 407(1) multiple times with a force smaller than this threshold force but strong enough to eventually crush the crushing element 490(1). This method does not create much tension in the material of the tube 400 to which the crushing element 490(1) is attached.

[0179] If element 490(1) is implemented as a molten element, this molten element is destroyed by melting them later in the manufacturing process. For example, tube 400 on which hinge 407(1) is manufactured is inserted inside another tube having holes in its structure that are aligned with each molten element. Then, an energy beam, such as a laser beam, is directed through such holes at the molten elements 490(1), and its energy is high enough to destroy the molten elements but not destroy or hardly destroy the sidewalls to which the molten elements are attached.

[0180] Crushing elements such as crushing element 490(1) can be applied between all opposing side walls 440(j) / 442(j), 454(j) / 456(j) and 462(j) / 464(j). If so, all these crushing elements are crushed or destroyed by melting, and after all hinges 407(j) are straightened, the tube 400 is 100% straight, and therefore there is still no reduction in tangential play. However, in practice, in most cases, invasive instruments are inserted, for example, into curved channels in the human body, which can cause most, if not most, of the hinges 407(j) to bend to a greater or lesser extent. In the bent state, at least some of the first side wall portion 444a(1) (and their equivalents in the other positions) are moved to the opposite side of side wall 446(1) (and their equivalents in the other positions), and the actual play is reduced from w1 to w3.

[0181] The tubes of invasive instruments may have a circular cross-section. However, the tubes may have other suitable cross-sections. For example, the tubes may have an oval, elliptical, or rectangular cross-section.

[0182] The tubes may be formed using suitable biocompatible polymer materials such as polyurethane, polyethylene, polypropylene, or other biocompatible polymers. The tubes may be made from any other suitable material and / or by any other suitable method. Other suitable materials may include stainless steel, cobalt-chromium, shape memory alloys such as Nitinol®, plastics, polymers, composites, or other curable materials.

[0183] The circumferential, longitudinal, and other slits can be formed by any known material removal technique such as photochemical etching, deep drawing, or scraping, but are preferably formed by laser or water cutting. All slits are open to both the outside and inside of the tube.

[0184] The longitudinal slits, circumferential slits, and U-shaped slits may have any appropriate length and width as required by the intended application. The longitudinal slits, circumferential slits, and U-shaped slits of the intermediate pipe may have the same or different lengths and / or widths.

[0185] Preferably, their length is 25-50%, more preferably 30-45%, and most preferably 35-40% of the outer circumference of the tubular member. The circumferential slits may have any suitable width. The circumferential slits of the same tubular member may have the same width or different widths. The circumferential slits may be narrower next to their endpoints and wider in their central portion.

[0186] The longitudinal slits and inclined slits may also have any appropriate length and width required depending on the intended application. The longitudinal slits and inclined slits of the tubular member may have the same or different lengths and / or widths.

[0187] The fidelity of bending and torsion along the length of a tubular member can be varied by changing the durometer rating of the material used to form different segments. Furthermore, the flexibility of the tubular member can be varied by changing the dimensions and positions of the circumferential slits, longitudinal slits, and inclined slits, and / or by changing the angle between the circumferential slits and the radial circumference.

[0188] The pipe 400 may have one of the following cross-sections: circular, oval, elliptical, or rectangular.

[0189] Pipe 400 is made of, at least partially, the following combination of materials: Biocompatible polymer materials including polyurethane, polyethylene, or polypropylene, stainless steel, Cobalt-chromium, Shape memory alloys such as Nitinol (registered trademark), plastic, polymer, Composite material, or Other curing materials It can be made from at least one of the following.

[0190] In one embodiment, the cutting pattern of the hinge 407(j) is derived from a material removal technique applied to the wall of the tube 400, which includes at least one of photochemical etching, deep drawing, cutting techniques, laser cutting, or water cutting. The material removal means may be a laser beam or waterjet cutting beam that melts and vaporizes the material, and the beam may have a width of 0.01 to 2.00 mm, more typically 0.015 to 0.04 mm in this application.

[0191] The wall thickness of the pipe depends on its application. For medical applications, the wall thickness may be in the range of 0.03 to 2.0 mm, preferably 0.03 to 1.0 mm, more preferably 0.05 to 0.5 mm, and most preferably 0.08 to 0.4 mm. The diameter of the pipe depends on its application. For medical applications, the diameter may be in the range of 0.5 to 20 mm, preferably 0.5 to 10 mm, and more preferably 0.5 to 6 mm. The radial clearance between adjacent pipes may be in the range of 0.01 to 0.3 mm.

[0192] The features of the present invention, as described with reference to Figures 9 to 12C, can be summarized as follows.

[0193] The present invention as shown in these figures relates to a tube including a hinge structure, the hinge structure comprising one or more hinges (407(j), j=1, 2, ..., J), each hinge (407(j)) comprising a first cutting pattern and a second cutting pattern within the tube (400), the first and second cutting patterns being located between the proximal and distal hinge sides of the hinge (407(j)), The first cutting pattern is, A first longitudinal bridge (404(j)) located at a first position, which extends in the longitudinal direction of the pipe (400) and connects the proximal hinge side and the distal hinge side, A first tangential slit (410a(j), 410b(j)) extending from a first longitudinal bridge (404(j)) in the first tangential direction (E) of the tube (400), comprising two first tangential slit portions (410a(j), 410b(j)) located at longitudinally shifted positions, wherein the first tangential slit portion prevents tangential rotation of the proximal hinge side relative to the distal hinge side. A first tangential slit (410a(j), 410b(j)) including two first tangential slit portions (410a(j), 410b(j)) connected to both ends of a first channel (425(j)) having a wall (440(j)) extending in the longitudinal direction and a second wall (442(j)) facing the first wall (440(j)), A second tangential slit (418a(j), 418b(j)) extending from a first longitudinal bridge (404(j)) in the second tangential direction (F) of the tube (400), wherein the first and second tangential directions are opposite, and the second tangential slit consists of two second tangential slit portions (418a(j), 418b(j)) located in longitudinally shifted positions, on the proximal hinge side relative to the distal hinge side. A second tangential slit (418a(j), 418b(j)) including two second tangential slit portions (418a(j), 418b(j)) connected to both ends of a second channel (427(j)) having a third longitudinally extending wall (444(j)) and a fourth longitudinally extending wall (446(j)) opposite to the third longitudinally extending wall (444(j)), so as to prevent tangential rotation. Define the area, The second cutting pattern is, A second longitudinal bridge (450(j)) located at a second position, extending longitudinally along the tube (400) and connecting the proximal hinge side and the distal hinge side, wherein the second position is rotated 180 degrees relative to the first position, A third tangential slit (424a(j), 424b(j)) extending from a second longitudinal bridge (450(j)) in the first tangential direction (E) of the tube (400), comprising two third tangential slit portions (424a(j), 424b(j)) located in longitudinally shifted positions, wherein the third tangential slit portion is positioned such as to prevent tangential rotation of the proximal hinge side relative to the distal hinge side. A third tangential slit (424a(j), 424b(j)) including two third tangential slit portions (424a(j), 424b(j)) connected to both ends of a third channel (429(j)) having a wall (454(j)) extending in the longitudinal direction of 5 and a sixth wall (456(j)) facing the fifth wall (454(j)), A fourth tangential slit (416a(j), 416b(j)) extending from a second longitudinal bridge (450(j)) in the second tangential direction (F) of the tube (400), comprising two fourth tangential slit portions (416a(j), 416b(j)) located in longitudinally shifted positions, wherein the second tangential slit portion prevents tangential rotation of the proximal hinge side relative to the distal hinge side. A fourth tangential slit (416a(j), 416b(j)) including two fourth tangential slit portions (416a(j), 416b(j)) connected to both ends of a fourth channel (431(j)) having a wall (462(j)) extending in the longitudinal direction of 7 and an eighth wall (444(j)) facing the seventh wall (462(j)). Define the area.

[0194] The first longitudinal bridge (404(j)) may have a first center of rotation (426(j)), the second longitudinal bridge (450(j)) may have a second center of rotation (458(j)), and each hinge (407(j)) may bend around an imaginary line passing through the first center of rotation (426(j)) and the second center of rotation (458(j)), and the first longitudinally extending wall (440(j)), the second longitudinally extending wall (442(j)), the third longitudinally extending wall (44 Each of the 4(j)) and the fourth longitudinal wall (446(j)) is formed as part of a circle having its center at the first center of rotation (426(j)), and each of the fifth longitudinal wall (454(j)), the sixth longitudinal wall (456(j)), the seventh longitudinal wall (462(j)), and the eighth longitudinal wall (444(j)) is formed as part of a circle having its center at the second center of rotation (458(j)).

[0195] The first cutting pattern may have two longitudinal slits (406(j), 408(j)) extending in the longitudinal direction and forming two longitudinal sides of the first longitudinal bridge (404(j)), and the second cutting pattern may have two further longitudinal slits (448(j), 452(j)) extending in the longitudinal direction and forming two longitudinal sides of the second longitudinal bridge (450(j)).

[0196] The two longitudinal slits (406(j), 408(j)) may be curved such that the first longitudinal bridge (404(j)) has a first width that increases toward its end.

[0197] Two further longitudinal slits (448(j), 452(j)) may be curved such that the second longitudinal bridge (404(j)) has a second width that increases toward its end.

[0198] The first tangential slit (410a(j), 410b(j)) may extend from the center (409(j)) of one of the two longitudinal slits (406(j), 408(j)), and the second tangential slit (418a(j), 418b(j)) may extend from the center (411(j)) of the other of the two longitudinal slits (406(j), 408(j)).

[0199] A third tangential slit (424a(j), 424b(j)) may extend from the center (423(j)) of one of the two further longitudinal slits (448(j), 452(j)), and a fourth tangential slit (416a(j), 416b(j)) may extend from the center (421(j)) of the other of the two further longitudinal slits (448(j), 452(j)).

[0200] One of the two first tangential slit portions (410a(j), 410b(j)) and one of the two fourth tangential slit portions (416a(j), 416b(j)) can overlap at least partially tangentially so as to form a first tangential bridge (403(j)) between them, the first tangential bridge (403(j)) having one end attached to the proximal hinge side and the other end attached to the distal hinge side.

[0201] One of the two second tangential slit portions (418a(j), 418b(j)) and one of the two third tangential slit portions (424a(j), 424b(j)) can overlap at least partially tangentially so as to form a second tangential bridge (405(j)) between them, the second tangential bridge (405(j)) having one end attached to the proximal hinge side and the other end attached to the distal hinge side.

[0202] The two first tangential slit portions (410a(j), 410b(j)) and the two third tangential slit portions (424a(j), 424b(j)) may be oriented to form a first angle with a plane perpendicular to the central axis of the tube (400), the first angle being -10° to +10°, more preferably -8° to +8°.

[0203] The two second tangential slit portions (418a(j), 418b(j)) and the two fourth tangential slit portions (416a(j), 416b(j)) may be oriented to form a second angle with a plane perpendicular to the central axis of the tube (400), where the second angle is -10° to +10°, more preferably -8° to +8°.

[0204] The pipe has the following characteristics: The first longitudinally extending wall (440(j)) and the second longitudinally extending wall (442(j)) have portions of the crushed first crushing element (480(j)) to reduce play between them. The third longitudinally extending wall (444(j)) and the fourth longitudinally extending wall (446(j)) have portions of the crushed second crushing element (482(j)) to reduce play between them. The fifth longitudinally extending wall (454(j)) and the sixth longitudinally extending wall (456(j)) have a portion of a crushed third crushed element to reduce play between them, or The seventh longitudinally extending wall (462(j)) and the eighth longitudinally extending wall (444(j)) have portions of the crushed fourth crushed element to reduce play between them. It may include at least one of the following.

[0205] Overview The examples and embodiments described herein are illustrative and not limiting to the invention. Those skilled in the art will be able to design alternative embodiments without departing from the claims. Reference numerals in parentheses in the claims should not be construed as limiting the claims. Items described in the claims or herein as separate entities may be implemented as one or more hardware items combining the features of the described items.

[0206] It should be understood that the present invention is limited only by the appended claims and its technical equivalents. In this specification and its claims, the verb “includes” and its conjugations are used in a non-restrictive sense to mean that the items following the word are included without excluding items not specifically mentioned. In addition, references to elements with the indefinite article “a” or “an” do not exclude the possibility of two or more elements being present unless the context explicitly requires that only one or one of the elements be present. Thus, the indefinite article “a” or “an” usually means “at least one.”

Claims

1. A steering device having a distal flexible tip portion (358) and a proximal bendable body portion (356) from the tip portion (358), comprising at least one tube (312), at least one inner tube (330) inside the at least one tube (312) or an outer tube (340) outside the at least one tube (312), and one or more steering wires (16(i)) inside the at least one tube (312), wherein the at least one tube (312) comprises a flexible tip section (301) within the flexible tip portion (358) and the bendable body portion (356) The steering device includes a flexible body section (309) and one or more steering wires (16(i)) which are spirally arranged in the circumferential direction of the steering device in at least a portion of the flexible body section (309), the steering device also includes one or more longitudinal force-blocking elements (322(k)) in at least one tube (312), the longitudinal force-blocking elements (322(k)) which are arranged parallel to the one or more steering wires (16(i)) in the flexible body section (309), the one or more longitudinal force-blocking elements (322(k)) which have a distal end and a proximal end, and the following features: If the steering device includes the outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) at the distal end of the main body section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) at the proximal end of the main body section (309), or If the steering device includes the inner tube (330), the distal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) at the distal end of the main body section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) at the proximal end of the main body section (309), or If the steering device includes the inner tube (330) and the outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) at the distal end of the main body section (309), and the proximal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) at the proximal end of the main body section (309). A steering device to which one of the following applies.

2. The steering device according to claim 1, wherein the one or more steering wires (16(i)) are spirally 180 degrees in the circumferential direction of the steering device in at least one portion of the flexible body section (309), providing path length compensation caused by bending of the at least one portion of the flexible body section (309).

3. The steering device according to claim 2, wherein the one or more steering wires (16(i)) are helical 180 degrees in the circumferential direction of the steering device over a certain number of times in an equal number of portions of the flexible body section (309), providing path length compensation caused by one or more bends in the number of portions of the flexible body section (309).

4. The steering device according to any one of claims 1 to 3, wherein the one or more steering wires (16(i)) are continuously spiral along the entire flexible body section (309).

5. A steering device according to any one of claims 1 to 4, comprising a plurality of steering wires (16(i)) positioned at equidistant locations parallel to the tangential direction of at least one pipe (312), and a plurality of longitudinal force blocking elements (322(k)), wherein at least one longitudinal force blocking element (322(k)) is located between two adjacent steering wires (16(i), 16(i+1)).

6. Each longitudinal force blocking element (322(k)) is attached to a spacer (318(i)) configured to maintain two adjacent steering wires (16(i)) at a desired tangential distance, and If the steering device includes the outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to the outer tube (340) via the attachment portion of the spacer (318(i)) to the outer tube (340), or If the steering device includes the inner tube (330), the distal end of each longitudinal force blocking element (322(k)) is attached to the inner tube (330) via the attachment portion of the spacer (318(i)) to the inner tube (330), or The steering device according to claim 5, wherein the steering device includes the inner tube (330) and the outer tube (340), the distal end of each longitudinal force blocking element (322(k)) is attached to at least one of the inner tube (330) or the outer tube (340) via the attachment portion of the spacer (318(i)) to at least one of the inner tube (330) or the outer tube (340).

7. The steering device according to claim 5 or 6, wherein a single longitudinal force blocking element (322(k)) is positioned between and equidistant from two adjacent steering wires (16(i), 16(i+1)).

8. A steerable device according to claim 7, wherein a pair of flexible spacers (320a(i), 320b(i)) is provided between two adjacent steering wires (16(i), 16(i+1)) proximal to the spacer (318(i)), the first of the pair of flexible spacers (320a(i), 320b(i)) is located between the single longitudinal force blocking element (322(k)) and the first of the two adjacent steering wires (16(i), 16(i+1)), and the second of the pair of flexible spacers (320a(i), 320b(i)) is located between the single longitudinal force blocking element (322(k)) and the second of the two adjacent steering wires (16(i), 16(i+1)).

9. The steering device according to any one of claims 1 to 8, wherein at least one of the longitudinal force blocking elements (322(k)) is provided with a through hole (325), and a lip extends from either the inner tube (330) or the outer tube (340) through each of the through holes (325), and the lip and the through hole (325) are configured to prevent tangential movement of the longitudinal force blocking element (322(k)) relative to the inner tube (330) or the outer tube (340), but to allow axial movement.

10. The steering device according to any one of claims 1 to 9, wherein the at least one tube (312) includes a ring-shaped end portion (314) at its distal end to which the one or more steering wires (16(i)) are attached.

11. The steering device according to claim 10, wherein the tip section of at least one tube (312) includes a spacer (316(i)) between each of two adjacent steering wires (16(i), 16(i+1)), and each spacer (316(i)) has a regular waveform pattern such as a block wave or sinusoidal pattern.

12. The steering device according to any one of claims 1 to 11, wherein the at least one tube (312) has one of the following cross-sections: circular, oval, elliptical, or rectangular.

13. The aforementioned at least one tube (312) is made of the following combination of materials: Biocompatible polymer materials including polyurethane, polyethylene, or polypropylene, stainless steel, Cobalt-chromium, Shape memory alloys such as Nitinol (registered trademark), plastic, polymer, Composite material, or Other curing materials A steerable device according to any one of claims 1 to 12, made from at least one of the following.

14. The steering device according to any one of claims 1 to 13, wherein the one or more steering wires (16(i)) and the one or more longitudinal force blocking elements (322(k)) are derived from a material removal technique applied to the wall of the at least one tube (312), which includes at least one of photochemical etching, deep drawing, cutting, laser cutting, or water cutting.

15. The steering device according to any one of claims 1 to 14, further comprising a Bowden cable section (355) on the proximal side of the proximal end of the main body section (356) to compensate for the difference in path length between the steering wire (16(i)) and the force-blocking element (322(k)).

16. An invasive device comprising a steerable device according to any one of claims 1 to 15, and a steering unit configured to bend the flexible tip portion (358) by operating the steering wire (16(i)), wherein the steering unit is one of a manually operated steering unit or a robotic steering unit.

17. A tube comprising a hinge structure, wherein the hinge structure comprises one or more hinges (407(j), j=1, 2, ..., J), each hinge (407(j) comprises a first cutting pattern and a second cutting pattern within the tube (400), the first cutting pattern and the second cutting pattern being located between the proximal hinge side and the distal hinge side of the hinge (407(j)), The first cutting pattern is, A first longitudinal bridge (404(j)) located at a first position, which extends in the longitudinal direction of the pipe (400) and connects the proximal hinge side and the distal hinge side, A first tangential slit (410a(j), 410b(j)) extending from the first longitudinal bridge (404(j)) in the first tangential direction (E) of the pipe (400), comprising two first tangential slit portions (410a(j), 410b(j)) located at longitudinally shifted positions, wherein the proximal hinge side is prevented from rotating tangentially relative to the distal hinge side. A first tangential slit (410a(j), 410b(j)) is provided, which includes two first tangential slit portions (410a(j), 410b(j)) connected to both ends of a first channel (425(j)) having a first longitudinally extending wall (440(j)) and a second longitudinally extending wall (442(j)) opposite to the first longitudinally extending wall (440(j)), A second tangential slit (418a(j), 418b(j)) extending from the first longitudinal bridge (404(j)) in the second tangential direction (F) of the pipe (400), wherein the first and second tangential directions are opposite, and the second tangential slit consists of two second tangential slit portions (418a(j), 418b(j)) located at longitudinally shifted positions, the proximal side relative to the distal hinge side A second tangential slit (418a(j), 418b(j)) is connected to both ends of a second channel (427(j)) which has a third longitudinally extending wall (444(j)) and a fourth longitudinally extending wall (446(j)) opposite to the third longitudinally extending wall (444(j)), thereby preventing tangential rotation on the hinge side. Define the area, The second cutting pattern is, A second longitudinal bridge (450(j)) located at a second position, which extends in the longitudinal direction of the pipe (400) and connects the proximal hinge side and the distal hinge side, wherein the second position is rotated 180 degrees with respect to the first position, A third tangential slit (424a(j), 424b(j)) extending from the second longitudinal bridge (450(j)) in the first tangential direction (E) of the pipe (400), comprising two third tangential slit portions (424a(j), 424b(j)) located at longitudinally shifted positions, which prevent tangential rotation of the proximal hinge side relative to the distal hinge side. A third tangential slit (424a(j), 424b(j)) including two third tangential slit portions (424a(j), 424b(j)) connected to both ends of a third channel (429(j)) having a fifth longitudinally extending wall (454(j)) and a sixth longitudinally extending wall (456(j)) opposite to the fifth longitudinally extending wall (454(j)), A fourth tangential slit (416a(j), 416b(j)) extending from the second longitudinal bridge (450(j)) in the second tangential direction (F) of the pipe (400), comprising two fourth tangential slit portions (416a(j), 416b(j)) located at longitudinally shifted positions, which prevent tangential rotation of the proximal hinge side relative to the distal hinge side. The fourth tangential slit (416a(j), 416b(j)) includes two fourth tangential slit portions (416a(j), 416b(j)) connected to both ends of a fourth channel (431(j)) having a seventh longitudinally extending wall (462(j)) and an eighth longitudinally extending wall (444(j)) opposite to the seventh longitudinally extending wall (462(j)). A pipe that defines a boundary.

18. The first longitudinal bridge (404(j)) has a first center of rotation (426(j)), and the second longitudinal bridge (450(j)) has a second center of rotation (458(j)), and each hinge (407(j)) can bend around an imaginary line passing through the first center of rotation (426(j)) and the second center of rotation (458(j)), and the first longitudinal wall (440(j)), the second longitudinal wall (442(j)), the third longitudinal wall (444(j)), and the fourth longitudinal wall The tube according to claim 17, wherein each of the (446(j)) is a circle formed as part of each circle having its center at the first center of rotation (426(j)), and each of the fifth longitudinal wall (454(j)), the sixth longitudinal wall (456(j)), the seventh longitudinal wall (462(j)), and the eighth longitudinal wall (444(j)) is a circle formed as part of each circle having its center at the second center of rotation (458(j)).

19. The tube according to claim 17 or 18, wherein the first cutting pattern has two longitudinal slits (406(j), 408(j)) that extend in the longitudinal direction and form two longitudinal sides of the first longitudinal bridge (404(j)), and the second cutting pattern has two further longitudinal slits (448(j), 452(j)) that extend in the longitudinal direction and form two longitudinal sides of the second longitudinal bridge (450(j)).

20. The tube according to claim 19, wherein the two longitudinal slits (406(j), 408(j)) are curved such that the first longitudinal bridge (404(j)) has a first width that increases toward its end.

21. The tube according to claim 19 or 20, wherein the two further longitudinal slits (448(j), 452(j)) are curved such that the second longitudinal bridge (404(j)) has a second width that increases toward its end.

22. The pipe according to any one of claims 19 to 21, wherein the first tangential slits (410a(j), 410b(j)) extend from the center (409(j)) of one of the two longitudinal slits (406(j), 408(j)), and the second tangential slits (418a(j), 418b(j)) extend from the center (411(j)) of the other of the two longitudinal slits (406(j), 408(j)).

23. The tube according to any one of claims 19 to 21, wherein the third tangential slit (424a(j), 424b(j)) extends from the center (423(j)) of one of the two further longitudinal slits (448(j), 452(j)), and the fourth tangential slit (416a(j), 416b(j)) extends from the center (421(j)) of the other of the two further longitudinal slits (448(j), 452(j)).

24. The tube according to any one of claims 17 to 23, wherein one of the two first tangential slit portions (410a(j), 410b(j)) and one of the two fourth tangential slit portions (416a(j), 416b(j)) overlap at least partially in the tangential direction to form a first tangential bridge (403(j)) between them, the first tangential bridge (403(j)) having one end attached to the proximal hinge side and the other end attached to the distal hinge side.

25. The tube according to any one of claims 17 to 24, wherein one of the two second tangential slit portions (418a(j), 418b(j)) and one of the two third tangential slit portions (424a(j), 424b(j)) overlap at least partially in the tangential direction so as to form a second tangential bridge (405(j)) between them, the second tangential bridge (405(j)) having one end attached to the proximal hinge side and the other end attached to the distal hinge side.

26. The tube according to any one of claims 17 to 25, wherein the two first tangential slit portions (410a(j), 410b(j)) and the two third tangential slit portions (424a(j), 424b(j)) are oriented to form a first angle with a plane perpendicular to the central axis of the tube (400), and the first angle is -10° to +10°, more preferably -8° to +8°.

27. The tube according to any one of claims 17 to 26, wherein the two second tangential slit portions (418a(j), 418b(j)) and the two fourth tangential slit portions (416a(j), 416b(j)) are oriented to form a second angle with a plane perpendicular to the central axis of the tube (400), and the second angle is -10° to +10°, more preferably -8° to +8°.

28. A tube according to any one of claims 17 to 27, having one of a circular, oval, elliptical, or rectangular cross-section.

29. The following combination of materials: Biocompatible polymer materials including polyurethane, polyethylene, or polypropylene, stainless steel, Cobalt-chromium, Shape memory alloys such as Nitinol (registered trademark), plastic, polymer, Composite material, or Other curing materials A tube according to any one of claims 17 to 28, made from at least one of the following.

30. The tube according to any one of claims 17 to 29, wherein the first and second cutting patterns are obtained from a material removal technique including at least one of photochemical etching, deep drawing, cutting, laser cutting, or water cutting.

31. The pipe according to any one of claims 17 to 30, wherein the two first tangential slit portions (410a(j), 410b(j)), the two second tangential slit portions (418a(j), 418b(j)), the two third tangential slit portions (424a(j), 424b(j)), and the two fourth tangential slit portions (416a(j), 416b(j)) preferably have the same length, which is 25 to 50%, more preferably 30 to 45%, and most preferably 35 to 40% of the outer circumference of the pipe.

32. The pipe according to any one of claims 17 to 31, wherein the two first tangential slit portions (410a(j), 410b(j)) and the two second tangential slit portions (418a(j), 418b(j)) are tapered toward the first longitudinal bridge (404(j)) and tapered toward their opposing ends, and the two third tangential slit portions (424a(j), 424b(j)) and the two fourth tangential slit portions (416a(j), 416b(j)) are tapered toward the second longitudinal bridge (450(j)) and tapered toward their opposing ends.

33. The following features: The first longitudinally extending wall (440(j)) and the second longitudinally extending wall (442(j)) have portions of the crushed first crushing element (480(j)) to reduce play between them. The third longitudinally extending wall (444(j)) and the fourth longitudinally extending wall (446(j)) have portions of the crushed second crushing element (482(j)) to reduce play between them. The fifth longitudinally extending wall (454(j)) and the sixth longitudinally extending wall (456(j)) have portions of a crushed third crushing element to reduce play between them, or The seventh longitudinally extending wall (462(j)) and the eighth longitudinally extending wall (444(j)) have portions of the crushed fourth crushing element to reduce play between them. A pipe according to any one of claims 17 to 32, comprising at least one of the following.

34. A steerable invasive instrument comprising a pipe according to any one of claims 17 to 33 and a steering unit configured to flex a flexible tip portion.

35. The steering unit is one of a manually operated steering unit or a robotic steering unit, according to claim 34, a steerable invasive device.

36. A steerable tube (312) comprising: a distal flexible tip section (301); a bendable body section (309) proximal to the flexible tip section (301); one or more steering wires (16(i)) configured to bend the flexible tip section (301) and spirally arranged in the circumferential direction of the steerable device in at least a portion of the flexible body section (309); and one or more spacer wires (322s(k)) providing a tangential spacer function between a first portion of the tube (312) and a second portion of the tube (312), wherein the one or more spacer wires (322s(k)) extend at least throughout the entire bendable body section (309) and spirally arranged within the flexible body section (309) in the same manner as the one or more steering wires (16(i)).

37. The steerable tube according to claim 36, wherein the first portion is at least one of a first control wire and a first steering wire (16(i)), and the second portion is at least one of a second control wire and a second steering wire (16(i+1)).

38. The steerable tube according to claim 36 or 37, wherein at least one of the one or more spacer wires (322s(k)) includes at least two spacer subwires (322s(k,1), 322s(k,2)).

39. The steerable tube according to claim 38, wherein the at least two spacer subwires (322s(k,1), 322s(k,2)) are separated by at least one slot (325s) and at least one of one or more bridges (323s) or one or more spacer elements (327).

40. The maneuverable tube according to any one of claims 36 to 39, wherein one or more spacer wires (322s(k)) are provided with a path length compensation mechanism at at least one of the distal and proximal ends of the maneuverable tube to compensate for variations in path length in the bendable body section (309).

41. The steerable tube according to any one of claims 36 to 40, wherein the first portion, the second portion, one or more steering wires (16(i)), and one or more spacer wires (322s(k)) are portions of the steerable tube and are defined by a cutting pattern in the steerable tube.

42. A steerable device comprising a steerable pipe according to any one of claims 36 to 41, and at least one inner pipe (330) inside the steerable pipe (312) or an outer pipe (340) outside the steerable pipe (312).

43. The steering device according to claim 41, comprising a control unit configured for at least one manual or robotic control of one or more steering wires (16(i)).

44. The steering device according to any one of claims 41 to 43, wherein the one or more spacer wires (322s(k)) are attached to at least one of the inner tube (330) and the outer tube (340) at a single position.

45. The steerable device according to any one of claims 41 to 44, wherein at least one of the inner tube (330) inside the steerable tube (312) or the outer tube (340) outside the steerable tube (312) is provided with at least one lip (352), and at least one of the one or more spacer wires (322s(k)) includes at least two spacer subwires (322s(k,1), 322s(k,2)) separated by a slot (325), and the at least one lip (352) is bent into the slot (325).

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