NL2022848B1

NL2022848B1 - Steerable instrument comprising a tube element

Info

Publication number: NL2022848B1
Application number: NL2022848A
Authority: NL
Inventors: Hendrik Louis Thissen Mattheus; Antonius Elisabeth Verbeek Marcel
Original assignee: Fortimedix Assets Ii B V
Priority date: 2019-04-01
Filing date: 2019-04-01
Publication date: 2020-10-08

Abstract

A cylindrical element with a hinge structure has: a first portion (524; 1124; 522(n-1); 1122(n-1)); a second portion (522(1); 1122(1); 522(n); 1122(n)) which is rotatable relative to the first portion (524; 1124; 522(n-1); 1122(n-1)) about two rotation sections (530(1); 1130(1); 530(n); 1130(n)) arranged at locations 1800 rotated relative to one another viewed in a tangential direction of the cylindrical element; an attachment element (502(1); 1006; 502(n)). The rotation sections (530(1); 1130(1); 530(n); 1130(n)) are implemented by: either the first portion (524; 1124; 522(n-1); 1122(n-1)) or the second portion (522(1); 1122(1); 522(n); 1122(n)) is provided with an opening accommodating a pin (556(1); 1156(1); 556(n); 1156(n)); the pin (556(1); 1156(1); 556(n); 1156(n)) is attached to a portion ofthe attachment element (502(1); 1006; 502(n)); the other one of the first portion (524; 1124; 522(n-1); 1122(n-1)) and the second portion (522(1); 1122(1); 522(n); 1122(n)) is attached to another portion of the attachment element (502(1); 1006; 502(n)); such that the first portion (524; 1124; 522(n-1); 1122(n-1)) and the second portion (522(1); 1122(1); 522(n); 1122(n)) cannot move relative to one another in a longitudinal direction, a tangential direction and a radial direction but are configured to rotate relative to one another about a center of rotation.

Description

P8077901NL4 -1- Steerable instrument comprising a tube element Field of the invention

[0001] The present invention relates to a steerable instrument for invasive and non-invasive type of applications, such as in surgery. Such instruments can be used in, for instance, the field of gastroscopy, colonoscopy, endoscopy, laparoscopy, and other medical applications. However, the steerable instrument according to the invention can also be used in non-medical applications.

Examples of the latter include inspection and/or repair of mechanical and/or electronic hardware at locations that are difficult to reach.

Background art

[0002] Transformation of surgical interventions that require large incisions for exposing a target area into minimal invasive surgical interventions, i.e. requiring only natural orifices or small incisions for establishing access to the target area, is a well-known and ongoing process. In performing minimal invasive surgical interventions, an operator such as a physician, requires an access device that is arranged for introducing and guiding invasive instruments into the human or animal body via an access port of that body. In order 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 that respect the possibility to use a natural orifice of the body would even be better.

Furthermore, the access device preferably enables the operator to control one or more degrees of freedom that the invasive instruments offer. In this way, the operator can perform required actions at the target area in the human or animal body in an ergonomic and accurate manner.

[0003] Steerable surgical invasive instruments in the field of gastroscopy, colonoscopy, endoscopy, laparoscopy, etc. are well-known in the art. The invasive instruments can comprise a steerable tube shaped device that enhances its navigation and steering capabilities. Such a steerable tube shaped device may comprise a proximal end part, a distal end part including at least one deflectable zone, and a rigid or flexible intermediate part, wherein the steerable tube shaped device, at its proximal end, further comprises a steering arrangement that is adapted to deflect the distal deflectable zone relative to a central axis of the tube shaped device. Such a steering arrangement may e.g. comprise a proximal deflectable zone, a ball shaped element, or a robot.

[0004] Most of the known instruments are complex to manufacture resulting in expensive instruments. Often, the distal end of the instruments comprise a flexible zone that is composed of separate links with hinging pins, coils or flexible plastic extrusions. Steering cables should be guided through holes through these links and/or through guiding eyes or hooks.

[0005] In most prior art devices, the steering arrangement comprises conventional steering cables with, for instance, sub 1 mm diameters as control members, wherein the steering cables are arranged between related deflectable zones at the distal end part and the steering arrangements at the proximal end part of the tube shaped device. Alternatively, control members may be implemented by one or more sets of longitudinal elements that are, e.g., formed by laser cutting in 40 tube elements. Further details regarding the design and fabrication of the abovementioned

P8077901NL4 -2- steerable tube and the steering arrangement thereof have been described for example in WO 2009/112060 A1, WO 2009/127236 A1, WO 2017/213491 A1, and WO 2018/067004. Such instruments can advantageously be used in endoscopic operations where the length need not be more than say 1 meter.

[0006] Sometimes a plastic extruded tube can be used with integrated channels for accommodating the cables. This renders an instrument with a simple construction. However, most plastics are rather weak. In case of very long instruments, e.g. longer than 1 meter, therefore, problems may arise due to the high forces exerted on the cables, both the steering cables and the actuation cable arranged to operate the tool at the distal end of the instrument. Problems may be undesired cuts, slip stick effects in the plastic tube and often a too high friction on the cables causing steering by the steering cables to be difficult and hard to manage. Moreover, mechanical properties of many plastics may be too poor to guarantee a high enough torsion stiffness which is required because the instruments should be capable of being rotated in use where they may have been guided through several curves impeding rotation of the whole instrument. Another disadvantage of a plastic tube may be that in case it is provided with an actuation cable to operate a tool at the distal end of the instrument the force in the actuation cable can increase to an extent that it exceeds the maximum longitudinal force allowed in the extruded plastic tube. If so, it would be impossible to operate the tool with an acceptable force. Moreover, if the plastic tube is in a curved arrangement and high force is exerted on the actuation cable, the channels for the steering cables may be deformed, especially in bent/deflected portions, such that the steering cables are clamped and cannot move freely anymore in the channels, thus, impeding proper operation of the steering of the distal deflectable zones.

[0007] In medical applications where longer instruments are necessary, such as in colonoscopy where 1.5 meter long instruments (or longer) may be applied, requirements as to steerability, flexibility, stiffness and accuracy increase seriously. There is a desire to develop such instruments with a better performance than prior art devices as to steerability also under end-effector actuation, longitudinal stiffness, torsion stiffness, durability and applicability of a mechanically actuated tool at the distal end. Moreover, there is a need to design such instruments such that they can be manufactured at such low costs that they are, preferably, disposable, thus avoiding the need to reuse them because of cost efficiency which requires applying cleaning and sterilization of the instrument after each use. Improper cleaning and sterilization may result in undesired post- operative complications which is a well-known and frequently occurring problem.

[0008] US2004/0236316 discloses an articulating mechanism for remote manipulation of various surgical instruments and diagnostic tools within, or to, regions of the body. Movement of segments at the proximal end of the mechanism results in a corresponding, relative movement of segments at the distal end of the mechanism. The proximal and distal segments are connected by a set of cables in such a fashion that each proximal segment forms a discrete pair with a distal segment. This configuration allows each segment pair to move independently of one another. Each segment comprises a link element having closed channels and optionally a channel being open towards the 40 outside surface. The channels accommodate cables for different purposes. Adjacent links touch

P8077901NL4 -3- another and are movable relative to one another in any angular direction relative to a longitudinal central axis of the instrument. Since the instrument has to be made of many separate links and all cables have to be guided through all channels of all links individually, manufacturing of the instrument according to this prior art document is time consuming and complex.

[0009] US2005096694 discloses an endoscopic or laparoscopic instrument which includes a distal tool, a rigid or flexible elongated shaft that supports the distal tool, and a proximal handle or control member, where the tool and the handle are coupled to the respective distal and proximal ends of the elongated shaft via bendable motion members. In Figures 21A-23D, this document shows a bendable section which is made from a solid element in which channels are made in its longitudinal direction to accommodate cables and which has a slotted structure to provide the required bendability. No materials used for making the bendable section are mentioned in this document. Moreover, the structure as shown would be extremely difficult to make from metal and therefor would be typically made from plastic. Both this material and the shown structure are unsuitable for longer devices because of high manufacturing cost and of too low mechanical properties for longitudinal and rotational stiffness

[0010] WO2005/067785 discloses an instrument for high-precision or surgical applications of a minimally invasive nature, comprising a distally positioned directable head, a shaft upon which the head is positioned, and a proximally positioned handgrip for operating the head. A ring of cables comprising longitudinally extending cables connects to the head. Each cable of the ring of cables is disposed such that at least a part of both sides is in direct contact with another cable of the ring of cables. The cables are fixedly secured in the radial direction, e.g. by an outer tube and an inner coil. A disadvantage of this known instrument is that the ring of cables is not blocked from tangential rotation relative to the outer tube and/or inner coil which may result in insufficient steerability of the instrument when the instrument is actuated to make two curves in different directions. Upon actuation, the pulled cables have the tendency to seek for the shortest route from the steering end to the distal end and therefore have the tendency to move to the inner curve of the instrument and thus tangentially rotate about the instrument longitudinal axis. This will result in loss of steering. Moreover, because the cables of the ring of cables at least in part contact adjacent cables there is friction between adjacent cables. Furthermore, in operation, in bent/deflected parts of the instrument a force may be exerted on some cables such that they have a tendency of being clamped between an adjacent cable and the outer tube / inner coil because of a “wedge” effect. Secondly, in a curve, the steering wires in the inner curve are clamped between the inner and outer tube if tension is applied to the outer steering wires. This can result in uncontrolled steering.

[0011] In this application, the terms “proximal” and “distal” are defined with respect to an operator, e.g. a physician that operates the instrument or endoscope. For example, a proximal end part is to be construed as a part that is located near the physician and a distal end part as a part located at a distance from the physician.

[0012] In the context of this document, to explain the invention, the term “colonoscopic instrument” will be used. The term is not used to limit its application to certain types of operations in a body or 40 elsewhere.

P8077901NL4 -4- Summary of the invention

[0013] The object of the present invention is to provide hinge structures as are explained with reference to figures 20a - 25.

[0014] This is achieved by devices and methods as claimed in the attached claims.

[0015] The hinge structures can be applied in tubular bodies explained with reference figures 1- 19c. These tubular bodies can be designed such that they meet high demands as to rotational stiffness, longitudinal stiffness, flexibility, with variable bending stiffnesses, along their entire length and deflectability at their deflectable zones which is especially an issue for instruments with a relatively small diameter and that are longer than 1 m. It becomes possible to make a single use instrument at fair costs which combines several functions like controlling a tool (if applied), rotating a tool, deflecting a tip section, adapting to curves in a longer duct, as required in colonoscopy and gastroscopy. The instrument is suitable for complex operations and is a step forward in minimal invasive gastro-intestinal surgery.

[0016] Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Moreover, separate features of different embodiments can be combined, even if not explicitly shown in the drawings or explained in the specification, unless such combination is physically impossible. The scope of the present invention is only limited by the claims and their technical equivalents.

Brief description of the drawings

[0017] The present invention will be discussed in more detail below, with reference to the attached drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which:

[0018] Fig. 1 depicts general setup for operations where two deflectable instruments are used, each with two distal deflectable zones.

[0019] Fig. 2 shows one deflectable instrument with two deflectable zones.

[0020] Fig. 3 shows a schematic picture of a colonoscopic instrument in use.

[0021] Fig. 4 shows a schematic picture of a gastroscopic instrument in use.

[0022] Fig.s 5A, 5B, 5C, 6A, 6B, 6C, 7A, 7B, 7C, 7D show different views of embodiments of the invention in which a tube with a corrugated cross section is used such as to define cable channels for steering cables.

[0023] Fig.s 8A, 8B, 8C show a tube having a corrugated cross section with cable channels covered with an integrated plastic liner.

[0024] Fig.s 9A, 9B show a hollow tube having a specially shaped liner with cable channels for steering cables.

[0025] Fig. 9C shows an alternative structure for the embodiment of Fig.s 9A and 9B.

40 [0026] Fig. 10A shows a cross section through two hollow tubes inserted into one another; the

P8077901NL4 -5- inside tube is extruded / machined / laser engraved such that it has cable channels at its outside surface; an outer liner closes the channels and protects the inside tube.

[0027] Fig. 10B shows a cross section through two hollow tubes inserted into one another; the inner tube is extruded / machined / laser engraved such that it has portions of cable channels at its outside surface; the outer tube is extruded / machined such that it has portions of cable channels at its inside surface aligned with the portions of the cable channels at the outside surface of the inner tube.

[0028] Fig.s 11A-11F show alternative embodiments where tangential movement of cables is blocked by other means than an intermediate tube element.

[0029] Fig. 12 shows a cross section view of an embodiment of the invention in which two tube shaped elements are inserted into one another; the inner tube has a cross section such as to define portions of cable channels; the outer tube has a cross section such as to define portions of cable channels; the cable channels of the inner and outer tubes are aligned.

[0030] Fig.s 13A, 13B show a cross section view of an embodiment of the invention with one tube which has a cross section such as to define complete cable channels for steering cables.

[0031] Fig.s 14A, 14B show an embodiment in which steering cables are arranged in additional tubes which are embedded in the cable channels of the tube and attached to the tube.

[0032] Fig.s 15A, 15B show a 3D and cross sectional view, respectively, of a proximal steering arrangement.

[0033] Fig.s 16A, 16B, 16C, 16D show some alternative slotted structures that can be used in flexible and deflectable sections of the instrument.

[0034] Fig. 17A shows a deflectable zone of a tubular body in a deflected position. Fig. 17B shows a cross section through such deflected tubular body at a position indicated by arrows XVIIB.

[0035] Fig. 18 shows an example of fracture elements in a slotted structure.

[0036] Fig.s 19A, 19B and 19C show an example of crimp bushings used to connect cables to the distal end of the tubular body.

[0037] Fig.s 20a-20d show hinge structures in accordance with an embodiment of the invention;

[0038] Fig. 21 shows a schematic cross section through a portion of a hinge structure according to an example;

[0039] Fig. 22 shows a schematic cross section through a portion of a hinge structure according to a further example;

[0040] Fig.s 234-23c show hinge structures in accordance with an other embodiment of the invention.

[0041] Fig.s 24a-24c show hinge structures in accordance with an other embodiment of the invention.

[0042] Fig. 25 shows hinge structures in accordance with an other embodiment of the invention. Description of embodiments

[0043] Figure 1 shows a non-limiting embodiment of an invasive instrument assembly 1 having an

P8077901NL4 -6- introducer accommodating two steerable invasive instruments 10. Figure 2 shows a side view of the steerable invasive instrument 10.

[0044] Each steerable instrument 10 (cf. Figure 2) comprises an elongated tubular body 18 having a proximal end part 11 including two actuation deflectable zones 14, 15, a distal end part 13 including two distal deflectable zones 16, 17, and a rigid intermediate part 12. The actuation deflectable zones 14, 15 in the present embodiment are configured as deflectable proximal zones, and will further be referred to as deflectable proximal zones. These deflectable proximal zones 14, 15 are connected to the distal deflectable zones by suitable longitudinal elements {not shown in figure 2). Such longitudinal elements may be cables. Alternatively, such longitudinal elements may be implemented by longitudinal strip shaped elements in tube elements and separated by longitudinal slots resulting from laser cutting predetermined patterns in the cylindrical tube, as explained in detail in for example WO 2009/112060 A1, WO 2009/127236 A1, WO 2017/213491 A1, and WO 2018/067004. As an alternative to laser cutting other techniques may be used, e.g., cutting by means of water beams. Also, 3D laser printing may be used. This also holds for other embodiments discussed below where reference is made to laser cutting.

[0045] By deflecting one such proximal deflectable zone 14, 15, respectively, in an angular direction from a longitudinal axis of the instrument a corresponding deflectable distal zone 16, 17 will also deflect. The rigid intermediate part 12 may also have one more flexible zones. However, these flexible zones are just flexible and their bending is not controlled by another bendable zone. If desired, one or more steerable deflectable distal zones 16, 17 can be provided.

[0046] At the distal end part 13 a tool, like a forceps 2 is arranged. At the proximal end part 11 a handle 3 is arranged that is adapted for opening and closing the jaws of the forceps 2 via, e.g., a suitable actuation cable (not shown) arranged within the instrument. Cable arrangements for doing so are well known in the art.

[0047] The steerable instrument typically comprises a handle 3 that is arranged at the proximal end part of the steerable tube for steering the tube and/or for manipulating the tool, such as forceps 2 that is arranged at the distal end part of the steerable tube. Alternatively, such a tool can for example be a camera, a manual manipulator, e.g. a pair of scissors, manipulators using an energy source, e.g. an electrical, ultrasonic or optical energy source. The instrument has no limitation as to the type of tool applied at the distal end. The type of handle 3 will be selected in dependence on the type of tool applied at the distal end, as will be evident to persons skilled in the art.

[0048] Figure 1 shows two instruments 18 of Figure 2 inserted into an introducer 20. Such an introducer 20 can, during an operation, be inserted into a trocar (not shown) arranged in, e.g., a abdominal wall of a human. Further details of an example of such an introducer 20 are disclosed in WO2015/084157. Both instruments 18 are deflected at proximal deflectable zones 14, 15 causing distal deflectable zones 16, 17 to be deflected too. The setup of Figure 2 can typically be used in laparoscopic applications.

[0049] Some locations to be operated in a body need specifically designed instruments. E.g., by making the intermediate part 12 of the instrument of Figure 2 completely flexible, the instrument 40 can also be used in areas in the body which are only accessible via curved natural access

P80779801NL1 -7- guides/channels, like the colon, the stomach via the oesophagus or the heart via curved blood vessels.

[0050] Figure 3 shows a schematic view of a colonoscope 42 in use. The colonoscope 42 is inserted into a colon 30 of a human body. Typically, the colon 30 has several almost square angled sections 32, 34, 36, and 38. If a surgeon needs to operate an area of the colon 30 upstream from square angled section 32 the colonoscope 42 needs to be inserted into the colon 30 along a distance of up to 1.5 meter. Moreover, the colonoscope 42 needs to be so flexible that it can be guided from an anus through all squared angled sections 32-38 of the colon 30 easily without risks of damaging the inner wall of the colon 30.

[0051] In operation, usually, several invasive instruments are inserted through the colonoscope 42 to provide one or more tools for some function at its distal end 44. In colonoscopy, such a tool typically includes a camera lens and a lighting element. To assist the surgeon in steering the camera view to the desired location and view in colon 30, typically, the distal end is deflectable from a longitudinal axis in all angular directions. This also holds for the inserted instruments with tools 2.

That can be implemented by providing such an instruments with one or more deflectable zones, like the deflectable zones 16, 17 of the instrument shown in Figure 2. These distal deflectable zones are controlled by suitable steering cables accommodated in the instruments connected to a suitable steering mechanism at the proximal ends of the instruments.

[0052] Figure 4 shows a schematic view of a gastroscope 56 in use. The gastroscope 56 is inserted into a stomach 50 of a human body via mouth, oral cavity / throat 54 and oesophagus 52. Especially when a surgeon needs to operate a lower portion of the stomach 50, the gastronoscope 56 needs to be guided through several curved/angled sections. Therefore, the gastroscope 56 needs to be flexible such that there is little risk of damaging inner walls of the mouth/throat 54, oesophagus 52 and stomach 50.

[0053] In operation, usually, several invasive instruments are inserted through the gastroscope 56 to provide one or more tools for some function at its distal end 60. In gastroscopy, such a tool typically includes a camera lens and a lighting element. To assist the surgeon in steering the camera view to the desired location and direction in stomach 50, typically, the distal end 60 of the is deflectable from a longitudinal axis in all angular directions. This also holds for the inserted instruments with tools 2. That can be implemented by providing such an instrument with one or more deflectable zones, like the deflectable zones 18, 17 of the instrument shown in Figure 2. These distal deflectable zones are controlled by suitable steering cables accommodated in the instruments connected to a suitable steering mechanism of these instruments. instruments according to the invention can be used in such colonoscopes and gastroscopes.

Therefore, general requirements to the presented instrument are that they show a high rotational stiffness, high longitudinal stiffness, flexibility along its entirely length and deflectability at its deflectable zones even in cases of long instruments, e.g., longer than 1 m, and with a relatively small diameter that fits to the working channels within or attached to colonoscopes and gastroscopes Also, such instruments should be designed such that they can be manufactured quite 40 easily. In accordance with the invention this can be achieved with instruments having a tubular body

P80779801NL1 -8- with at least one tube element made from a metal and provided with suitable slotted structures to provide the instrument with enough flexibility along its entire length

[0054] Figures 5A-5C show a first embodiment of the present invention. Figure 5C is an enlarged version of the tip of the instrument shown in Figure 5A. Figure 5B is a cross section view through the tip at a location indicated with the two arrows VB in Figures 5A and 5C.

[0055] Figure 5A shows a 3D view of the distal end 70 of the elongated tubular body 18 of the steerable instrument between a tool and the proximal end of the steerable instrument according to the embodiment. The elongated tubular body 18 comprises an outer tube element 86, an intermediate tube element 88 and an inner tube element 92. The elongated tubular body 18 may comprise more tube elements located outside the outer tube element 86 or inside the inner tube element 92 or between the inner and outer tube elements 92, 86 at either side of the intermediate tube element 88. The inner tube element 92 surrounds an elongated channel 94 extending from the distal end 70 towards the proximal end of the tubular body 18. Preferably, all tube elements 86, 88, 92 are symmetrical about a central longitudinal axis 98 of the tubular body 18. They are shown as cylindrical elements with a substantial circular cross section. However, they may have other cross sections like an oval, hexagon, rectangle, etc. Moreover, it is observed that cross sections of several tube elements of the present invention may deviate from an ideal circle, or oval or hexagon, etc.

[0056] Intermediate tube element 88 functions as a tangential rotation blocker for cables 90.

[0057] In the embodiment shown, the tubular body 18 has one deflectable zone 17. Between this deflectable zone 17 and the proximal end the tubular body has a flexible zone 12a. In the deflectable zone 17 and the flexible zone 12a all tube elements 86, 88, and 90 are flexible. The deflection of deflectable zone 17 is controlled by steering cables 90. When operating the steering cables 90 also the flexible zone 12a will show a tendency to deflect. However, preferably, the deflectable zone 17 is more flexible than flexible zone 12a such that deflectable zone 17 will bend more easily than flexible zone 12a when steering cables 90 are operated. Moreover, cables 90 will typically be operated when the tubular body 18 has been inserted in an object to its target location and, then, deflectable zone 17 will have more free space in the object than the flexible zone 12a which may be located in a rather fixed orientation as determined by one or more curved sections (like a colon) of the object through which the tubular body 18 extends. E.g., when tubular body 18 has been inserted into a colonoscope or gastroscope to such an extent that the distal end, including deflectable zone 17, extends from the distal end of the colonoscope or gastroscope, flexible zone 124 will be rather fixed in the curvature of the colonoscope or the gastroscope and its surrounding curvature of the colon or upper intestinal tract, and deflectable zone 17 can deflect freely. This helps in only deflecting deflectable zone 17 when operating steering cables 90.

[0058] The intermediate tube element 88 has an inner surface and an outer surface and is shaped such that it defines longitudinal cable channels 96, 97 in the longitudinal direction of the tubular body 18. Figure 5A-5C show six such cable channels 96 at the outside of intermediate tube element 88 and six such cable channels 97 at the inside of intermediate tube element 88. In the embodiment shown in Figure 5A, each cable channel 96, 97 accommodates one steering cable 90. In one 40 embodiment, all cable channels 96, 97 extend in a straight direction in parallel to the central axis

P8077901NL4 -9-

98. However, the cable channels 96, 97 may, alternatively spiral in the longitudinal direction of intermediate tube element 88. The spiral form may be such that a tangential location of a channel 96, 97 at the distal end and a tangential location of the same channel 96, 97 at the proximal end of the tubular body 18 are relatively shifted by a rotation angle of e.g. 90°, 180° or 270°. However, any other rotation angle can be implemented if desired.

[0059] The tip of the outer tube element 86 comprises a plurality of longitudinal slots 80. In the embodiment shown there are six of them and they are equally spaced in the tangential direction. They are open towards the outer distal edge of the outer tube element 86. Between each two adjacent slots 80 there is a strip 84 at the most distal end of the outer tube element 86. So, in total there are six strips 84. Each slot 80 is aligned with one cable 90. These slots 80 are used for alignment with crimp bushings which are applied to clamp cables 90 at the distal end such that cables 90 cannot move in their cable channels in the proximal direction anymore at the most distal end. Such a connection with crimp bushings is shown in Figures 19A and 19B. Of course, any other known means of fastening the distal ends of the cables 90 to the tip of the tubular body 18 like welding or providing cables 90 with suitable beads may be used instead.

[0060] Each strip 84 is provided with a lip 82. Each lip 82 is aligned with an outside portion of the intermediate tube element 88 and serves as a laser welding portion of strip 84. Each lip 82 is laser welded to such outside portion of the intermediate tube element 88 such that, at the tip, the outer tube element 86 is firmly attached to the intermediate tube element 88. Thereby, intermediate tube element 88 and outer tube element 86 cannot rotate or move relative to one another at the distal end of the tubular body, thus, providing stability. Thus, at the distal end, cables 90 are blocked from tangential rotation relative to the outer tube element 86. This can, alternatively, be established by other features like laser welding without lips, or lips that are present in at least one of the intermediate tube element 88 and outer tube element 86 which are bent into a suitable aligned opening in the other one of these tube elements 86, 88. Gluing or brazing is also a possible option for attaching.

[0061] Located proximally from the slots 80 the outer tube element 86 comprises a deflectable section 72 aligned with deflectable zone 17. This deflectable section 72 is separated from the tip of the outer tube element 86 by a non-flexible section 78. Preferably section 78 is a ring shaped portion of the outer tube element 86 that has no, or hardly any holes or slots in it such that it cannot be bent. Section 78 is optional and can be left out.

[0062] In the embodiment shown in Figure 5A, deflectable section 72 is implemented by laser cutting a predetermined pattern of slots in the material of the outer tube element 86. These slots extend through the whole thickness of the material. The slots are arranged such that the deflectable section 72 operates as a hinge and is optimized as to deflectability relative to the flexible zone 12a. Apart from that, deflectable section 72 should have a certain minimum rotational stiffness and minimum longitudinal stiffness. Preferably, the deflectable section 72 does not show any play in the longitudinal and tangential direction. However, for the deflectable section 72 this is not an absolute requirement. Any suitable slotted structure known from the prior art can be used to that effect. More 40 details as to a preferred deflectable section 72 are shown in and explained with reference to Figure

P8077901NL4 -10- 16A.

[0063] In the flexible zone 12a, outer tube element 86 has a flexible section 74. In a preferred implementation, the flexible section 74 is also implemented by laser cutting a predetermined pattern of slots in the material of the outer tube element 86. These slots extend through the whole thickness of the material. The slots are arranged such that the flexible section 74 is flexible to a certain predetermined extent but is optimized as to rotational stiffness. Again, this flexible section 74 should also have a certain minimum longitudinal stiffness. Preferably, the flexible section 74 does not show any play in the longitudinal and tangential direction. Any suitable slotted structure known from the prior art can be used to that effect. More details as to a preferred flexible section 74 are shown in and explained with reference to Figure 16B.

[0064] In an embodiment, the flexibility of the flexible section 74 is less than the flexibility of the deflectable section 72.

[0065] Between deflectable section 72 and flexible section 74, outer tube element 86 may have a ring shaped, non-flexible section 76. So, preferably, ring-shaped section 76 has no, or hardly any holes or slots in it such that it cannot be bent. Ring-shaped section 76 is optional and can be left out.

[0066] At the proximal side of deflectable section 72, outer tube element 86 comprises a plurality of lips 75. Like lips 82 they are aligned with an outside portion of the intermediate tube element 88 and serve as laser welding portions. Each lip 75 is laser welded to such outside portion of the intermediate tube element 88 such that, at the proximal side of deflectable section 72, the outer tube element 86 is firmly attached to the intermediate tube element 88. Other mechanisms to connect outer tube element 86 to intermediate tube element 88 may be applied instead, like direct welding or using lips in one of the tube elements 86, 88 bent into aligned openings in the other one of the tube elements 86, 88. Gluing or brazing is also a possible option for attaching.

[0067] Also at locations along flexible zone 12a, outer tube element 86 may be attached to intermediate tube element 88, e.g. by laser welding suitable welding lips, shaped like lips 75, to outer portions of intermediate tube element 88 or using lips in one tube element bent into suitable aligned openings in the other tube element. Gluing or brazing is also a possible option for attaching. This provides the tubular body 18 with more stability and less risks of being deformed during use.

In this way, intermediate tube element 88 cannot tangentially rotate relative to outer tube element 86 and functions even better as a tangential rotation blocker for cables 90.

[0068] The need to attach all applied tube elements 86, 88, 92 at several locations to one another along the entire length of the instruments increases the longer the instrument is. l.e., hinges at the same longitudinal locations in all applied tube elements 86, 88, 92 should be aligned at all times, both longitudinally and tangentially, in such longer instruments. The applied tube elements should, then, be free of rotation relative to one another as much as possible. For longer instruments it is also necessary to prevent the intermediate tube element 88 from being rotatable relative to the inner tube element 92 and/or outer tube element 86 (which ever one is applied) to prevent cables 90 from being rotated tangentially. If the applied tube elements would not be fixed in tangential 40 rotation, a lot of slack and play may occur, resulting in instable controllability. Laser welding is,

P8077901NL4 -11- therefore, a preferred method because that results in zero play.

[0069] Outer tube element 86 has, preferably, a uniform thickness and is preferably made from a metal. Suitable materials are steel alloys like stainless steel, cobalt-chromium alloys, or a shape memory alloy such as Nitinol®. However, any other material that can meet the requirements as to rotational stiffness, longitudinal stiffness, play and manufacturability as regards the above explained slots / slotted structures can be selected too, like plastic, polymer, composites or other cutable material in which hinges can be made. Preferably, the material has an as low as possible friction coefficient relative to cables 90 , a material like UHMWPE and/or Teflon™ .

[0070] The thickness of outer tube element 86 depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of the outer tube element 86 depends on its application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5- 10 mm, more preferably 0.5-6 mm.

[0071] The slots of the slotted structures 72, 74 in outer tube element 86 can be made by laser cutting. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 um. Slots having a width of 0 um or very close to that can be made by cutting a notch on locations where the slot should come, which notch does not extend through the whole thickness of the material but weakens the material to such an extent that one can easily break the material along the notch. Cutting such a notch can be done by laser engraving or by interruptions of the cutting path. This will be explained in more detail with reference to Figure 19 hereinafter.

[0072] In the embodiment of Figures 5A-5C, the cross section of intermediate tube element 88 has a corrugated structure along its entire longitudinal direction. Here, the intermediate tube element 88 has a uniform thickness. So, also both its inner and outer surface have a corrugated structure.

[0073] The corrugated structure may be sine shaped and may be entirely symmetric. Here, the term “sine shaped” is used to refer to a shape that looks like a sine but is not really an ideal sine. The corrugated structure has a plurality of outer peaks 108. In the embodiment shown there are six outer peaks 100. They are all located at the same radial distance from the central axis 98 and may touch the inside of outer tube element 86. Lips 75 and 82 of outer tube element 86 are attached to intermediate tube element 88 at such outer peaks 100. Outer tube element 86 may also be attached to intermediate tube element 88 at locations in flexible zone 12a, e.g. by means of laser welding suitable welding lips in outer tube element 86 which are aligned with outer peaks 100.

[0074] When a connection between outer tube element 86 and intermediate element 88 is made by means of lips and suitable aligned openings, as referred to above, such lips are preferably made in outer tube element 86 and such openings in intermediate element 88. The openings are then located at such peaks 100. Gluing or brazing is also a possible option for attaching.

[0075] The corrugated structure also has a plurality of inner peaks 102. In the embodiment shown there are six inner peaks 102. They are all located at the same radial distance from the central axis 98 and may touch the outside of inner tube element 92. Preferably, one or more of those inner 40 peaks 102 are attached to inner tube element 92 somewhere in the tip, e.g. at the same distance

P8077901NL4 -12- from the distal edge as the lips 82. When the inner tube element 92 and intermediate tube element 88 are both made from a metal, such an attachment may be implemented by laser welding.

However, any other suitable attachment technique may be used instead, like gluing or brazing or lips in one of the tube elements and suitable aligned openings in the other tube element as referred to above. As explained above, such connections / attachments between adjacent tube elements may be present along the entire length of the instrument.

[0076] The corrugated structure of intermediate tube element 88 is the same along its entire length and defines longitudinal channels extending from the distal end to the proximal end of the tubular body 18 for accommodating cables 90. The corrugated structure has a plurality of outward facing cable channels 96 and a plurality of inward facing cable channels 97. Here, there are six cable channels 96 and six cable channels 97. However, any other number may be used instead. At least three such cable channels 96, 97 are necessary to accommodate three steering cables 90 to allow for a deflection of the deflectable zone 17 in all directions. All cable channels 96, 97 are preferably equally spaced in the tangential direction.

[0077] The corrugated structure may spiral in the longitudinal direction such that it defines spiralling cable channels 96, 97.

[0078] Intermediate tube element 88 is provided with a deflectable section in deflectable zone 17 and a flexible section in flexible zone 12a. Any suitable technical implementation can be used. E.g., slotted structures like the ones shown at 72 and 74 in the outer tube element 86 can be used. An alternative slotted structure 106 is shown in corrugated intermediate tube element 88 shown in Figure 7A. The example slotted structure 106 of Figure 7A is shown in more detail in Figure 16C. as a further alternative, any of the slotted structures shown in detail in Figures 16A-16C can be used in the deflectable section of the intermediate cylindrical section 88 whereas the rest of the structure of intermediate tube element 88 is flexible, such that it bends easy enough for a certain envisaged application, like colonoscopy.

[0079] Intermediate tube element 88 has, preferably, a uniform thickness and is preferably made from a metal. Suitable materials are steel alloys like stainless steel, cobalt-chromium or a shape memory alloy such as Nitinol®. However, any other material that can meet the requirements as to rotational stiffness, longitudinal stiffness, play and manufacturability as regards the above explained slots / slotted structures can be selected too, like plastic, polymer, composites or other cutable material in which hinges can be made. Preferably, the material has an as low as possible friction coefficient relative to cables 90. like UHMWPE and/or Teflon?" may be used. Intermediate tube element 88 can be made by shaping an originally cylindrical tube with circular cross section into the desired form.

[0080] The thickness of intermediate tube element 88 depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The inner and outer diameters of the intermediate tube element 88, as defined by its internal peaks 102 and outer peaks 100, depend on its application. For medical applications the inner and outer diameters may be in a range of 0.5- 40 20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm. The outer diameter of intermediate tube

P8077901NL4 -13- element 88 is selected such that it is substantially the same as the inner diameter of outer tube element 86. Then, outer tube element 86 touches intermediate tube element 88 at its outer peaks

100. Similarly, the inner diameter of intermediate tube element 88 is selected such that it is substantially the same as the outer diameter of inner tube element 92. Then, inner tube element 92 touches intermediate tube element 88 at its internal peaks 102.

[0081] Even though the intermediate tube element 88 has a corrugated cross section, experiments have shown that the slots of the slotted structure 106 in intermediate tube element 88 can be made by laser cutting with a laser beam. Such a laser beam may be directed perpendicular to the central axis 98. However, it is also possible to direct such a laser beam such that it is located in a plane perpendicular to the central axis 98 and substantially perpendicular to the outer surface of intermediate tube 88. Here “substantially” means within +/- 10% of an angle of 90°. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0- 50 um, more preferably 0-30 um.

[0082] Cables 90 are selected such that their diameter is slightly less than the height of channels 96, 97, where the height of the channels 96, 97 is defined as their cross section width in the radial direction. Suitable cable diameters are within a range of, for instance, 0.1 to 1.0 mm. The cross section width of channels 96, 97 should be larger than the cable diameter at any location of channels 96, 97. Then, cables 90 can move in channels 96, 97 in the longitudinal direction substantially without any friction. Only in bent portions of the tubular body 18 some of the cables 90 will experience friction, as will be addressed later on.

[0083] The cables 90 should be selected such as to have an as high as possible tensile strength in combination with an as low as possible bending stiffness and as high as possible longitudinal stiffness. Therefore, preferably, the cables 90 are made from several twisted metal wires instead of a solid single wire. Alternatively, materials like Kevlar™, aramid or dyneema can be used. Such cables can contain several twisted wires and may have a circular cross section, or even an oval or flat cross section.

[0084] Because the corrugated structure of intermediate tube element 88 is, by nature, difficult to deform by an external mechanical force, both in the radial and tangential direction, it will function as walls of channels 96, 97 that are difficult to be deformed. This assists significantly in keeping the entire tubular body 18 in its original shape as much as possible even when it has a length of 1 meter or more and is inserted into a curved duct like a human colon, and is rotated by the surgeon at the proximal end to bring the tool at the distal end in a desired orientation.

[0085] Inner tube element 92 has an internal channel 94. The cross section dimensions of internal channel 94 are such as to be suitable for the intended purpose. In many applications, the internal channel 94 accommodates an actuation cable 184 (cf. Figure 15B) that may be thicker and stronger than steering cables 90. Such an actuation cable 184 is, at its proximal end, connected to the handle 3 and operated by the grips of handle 3. l.e., moving the grips towards and away from one another results in longitudinal movement of the actuation cable which can be transformed into an opening and closing movement of a pair of scissors or the jaws of a clamping device. Such techniques are 40 widely known to persons skilled in the art and need no further explanation here.

P8077901NL4 -14-

[0086] Channel 94 may accommodate one or more electrically conductive or optical wires. Such electrical or optical wires may transport electrical or optical energy to a tool using that energy to perform a predetermined function like heating, burning, lighting, sensing (looking), etc.

[0087] Inner tube element 92 has, preferably, a uniform thickness and needs to be flexible at least in the deflectable zone 17 and flexible zone 12a. Thus, tube element 92 can be entirely flexible along its entire length. It can, e.g. be made of a spring or coil. Alternatively it can be made of a flexible material like plastic. As a further alternative, it can be made of a metal of which the flexibility is, e.g., increased in the deflectable zone 17 and flexible zone 12a by suitable slotted structures as known from the prior art or as explained with reference to Figures 16A-16C hereinafter.

[0088] Suitable materials for inner tube element 92 are steel alloys like stainless steel, cobalt- chromium alloysor a shape memory alloy such as Nitinol®. However, any other material that can meet the requirements as to rotational stiffness, longitudinal stiffness, and play and manufacturability as regards the above explained slots / slotted structures can be selected too, like plastic, polymer, composites or other cutable material in which hinges can be made. Preferably, the material has an as low as possible friction coefficient relative to cables 90, a material like UHMWPE and/or Teflon™.

[0089] The thickness of innertube element 92 depends on its application. For medical applications the thickness may be in a range of 0.03-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of the inner tube element depends on its application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5- 10 mm, more preferably 0.5-6 mm. The outer diameter of inner tube element 92 is selected such that it is substantially the same as the inner diameter of intermediate tube element 88 as defined by its internal peaks 102. Then, inner tube element 982 touches intermediate tube element 88 at its internal peaks 102.

[0090] Slots of slotted structures in inner tube element 92, if applied, can be made by laser cutting. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 um.

[0091] To provide the tubular body 18 with enough rotational stiffness and longitudinal stiffness, at least one of outer tube element 86, intermediate tube element 88 and inner tube element 92 is made from a metal like steel alloy, cobalt-chromium alloy and Nitinol®.

[0092] Figures 6A, 6B, 6C show an embodiment in which only the outside cable channels 96 are accommodating cables 90. So, the inside channels 97 are empty or and designed to contain electrical wires, optical fibres or wires for some kind of mechanical actuation. Thus, in the embodiment of Figures 6A, 6B, 6C no inner tube element 92 is needed for keeping cables 90 in place. For the rest all elements are the same as in the embodiment of Figures 5A, 5B, 5C. They are indicated with the same reference signs.

[0093] To provide the tubular body 18 with enough rotational stiffness and longitudinal stiffness, here, at least one of outer tube element 86 and intermediate tube element 88 is made from a metal like steel alloy, cobalt-chromium alloy and Nitinol®.

40 [0094] Figures 7A, 7B, 7C show an embodiment in which the cuter channels 96 are empty and do

P8077901NL4 -15- not accommodate cables 90. They may contain electrical wires, optical fibres or wires for some kind of mechanical actuation. So, the embodiment of Figures 7A, 7B, 7C does not need outer tube element 86 for keeping cables 90 in place. For the rest all elements are the same as in the embodiment of Figures 5A, 5B, 5C. They are indicated with the same reference signs.

[0095] Thus, in Figure 7A, one can clearly see the outside of intermediate tube element 88 (note that this is the same intermediate tube element 88 of figures 5A-5C and 6A-6C). Intermediate tube element 88 has a tip section 104 at the distal end. Proximally from the tip section 104, intermediate tube element 88 has a deflectable section, here implemented as a hinge structure 106 which is aligned with deflectable zone 17. Proximally from the hinge structure 108, the intermediate tube element 88 has an intermediate section 108.

[0096] Crimp bushings or laser welded bushings may be provided to connect cables 90 to the tip section.

[0097] In the shown embodiment, the hinge structure 106 is made by a slotted structure comprising a plurality of slots. The hinge structure 106 may be manufactured by laser cutting a predetermined pattern of slots in the material of the intermediate tube element 88. These slots extend through the whole thickness of the material. The slots are arranged such that the hinge structure 106 is optimized as to deflectability relative to the flexible zone 108. Apart from that, deflectable section should have a certain minimum rotational stiffness and minimum longitudinal stiffness. Preferably, the hinge structure 106 does not show any play in the longitudinal and tangential direction. However, for the hinge structure 106 this is not an absolute requirement. Any suitable slotted structure known from the prior art can be used to that effect. More details as to a preferred hinge structure 106 are shown in and explained with reference to Figure 16C.

[0098] The intermediate section 108 is aligned with flexible zone 12a and should be flexible. So, it should be either made of a flexible material or made flexible, e.g., by providing this intermediate section 108 with a suitable slotted structure. Any suitable slotted structure known from the prior art may be used. Advantageously, a slotted structure is used as shown in and explained with reference to Figure 16C.

[0099] In an embodiment, deflectable section 106 is more flexible than intermediate section 108.

[00100] The structures shown in Figures 5A-5C, 6A-6C, and 7A-7C may suffer from cables 90 getting stuck because of a wedge effect in bent or deflected portions of the tubular body 18. This will be explained in more detail with reference to Figures 17A and 17B now.

[00101] Figure 17A shows bendable zone 12 of tubular body 18 in a bent position. The tubular body 18 is one as explained in further detail in Figures 8A, 9B (and viewed from the opposite side). Figure 17B shows a cross section through such bent tubular body 18 at a position indicated by arrows XVIIB.

[00102] It is assumed that in the case of Figure 17A the tip of the deflectable end 17 is desired to be deflected downward, as seen in the plane of the drawing. This is done by exerting a pulling force on cables 90 located in the lower portion of intermediate tube element 88 as seen in the surface of the drawing and relaxing or pushing the cables 90 in the upper portion of intermediate tube element 40 88 as seen in the surface of the drawing. Stated differently, the lower located cables 90 are pulled

P8077901NL4 -16- towards the left from the proximal end in the surface of the drawing of Figure 17A and the upper located cables 90 are relaxed from the proximal end such that they can move in the right direction.

[00103] Because of the bent status at the cross section location of Figure 17B, this will cause downward directed forces 110, 112, 120, 123, 114, 118 on cables 90 as shown in Figure 17B (here only the forces on the cables located in outer channels 96 are shown). The closer cable 90 is located at the downside of the bent tubular body 18 the greater downward directed force 110, 112, 120, 123, 114, 118 on cable 90 will be. Channels 96 are not circular but are tapering from their central axis, which substantially coincides with a central axis of a cable 90, towards an area of contact between intermediate tube element 88 and cuter tube element 86. At the lower side and middle side of the tubular body 18, the exerted forces 110, 112, 120, and 122, respectively, have components 111, 113, 121, and 123, respectively, directed towards tapered sections 99 of the channels 96 such that a “wedge” effect occurs and there is a risk the cables 90 get clamped, which results in longitudinal friction on the cables 90, or even get stuck between intermediate tube element 88 and outer tube element 86. For shorter tubular bodies 18 and relatively small forces exerted on the cables 90, this may not be serious but for longer instruments which are already curved at many locations in use, like in colonoscopy, this increase in friction on the cables 90 may become more serious and prevent proper deflectability of the deflectable zone 17.

[00104] As may be evident to persons skilled in the art this effect may also occur in the deflectable zone 17 itself.

[00105] Several embodiments of the present invention solve this issue. One such solution is schematically shown in Figure 7D which shows a variant of the embodiment of Figures 7A-7C. Figure 7D shows an intermediate tube element 88f shaped such that it defines inwardly directed cable channels 97. Each cable channel 97 is partly surrounded by a cable tube portion 101. Each two adjacent cable tube portions 101 are mutually connected via intermediate tube element portions 103 all located on a same circle about central axis 98.

[00106] An inner tube element 92a is provided inside intermediate tube element 88f. Inner tube element 88f is provided with a plurality of rims 105, one rim 105 per cable channel 97. Each rim 105 extends to a certain predetermined extent in an open portion of one cable channel 97 facing towards central axis 98. Moreover, each rim 105 extends along the entire length of inner tube element 92a.

Each two adjacent rims 105 are mutually connected via inner tube element portions 107 all located on a same circle about central axis 98, such that intermediate tube element portions 103 are aligned with inner tube element portions 107 such that one intermediate tube element portion 103 touches one inner tube element portion 107.

[00107] There may be small tapered sections 99 of cable channel 97 between inner tube element 92a and intermediate tube element 88f, as indicated in Figure 7D. However, because rims 105 extend slightly into channels 97 and support cables 90, risks for cables 90 to get stuck in these tapered sections 99 are reduced.

[00108] As a further alternative, inner tube element 92 may be provided with a plurality of longitudinal rims, two per cable 20. Each one of such rims extend outwardly from the outer surface 40 of inner tube element 92 and are aligned with one tapered section 99 along the entire length of

P8077901NL4 -17- tubular body 18. So, each cable 90 is, then, supported by two such rims.

[00109] For the rest, the same properties may apply to inner tube element 92a as to inner tube element 92.

[00110] Another solution may be providing extra tubes in channels 96, 97, e.g. extra tubes 166 as shown in and explained hereinafter with reference to Figures 14A, 14B.

[00111] To provide the tubular body 18 with enough rotational stiffness and longitudinal stiffness, at least one of intermediate tube element 88 and inner tube element 92/92a is made from a metal like steel alloy, cobalt-chromium alloy and Nitinol®.

[00112] Another solution is shown in Figures 8A, 8B, 8C. Figure 8B is a cross section at a location indicated with arrows VIIIB, and Figure 8C is an enlarged view of the tip section of the tubular body

18. Here, the tubular body 18 comprises an outer tube element 130 and an intermediate tube element 88a. No inner tube element is provided. Instead of intermediate tube element 88a, alternatively, intermediate tube element 88 may be used or another suitable form.

[00113] The outer tube element 130 is shaped such as to have a plurality of internal channels 132 for accommodating cables 90. Preferably these channels 132 have a circular cross section, like cables 90. Figure 8C shows these channels 132 without the cables 90. The channels 132 are completely surrounded by the material of the outer tube element 130. Again, the channels 132 may have a spiral form in the longitudinal direction of the tubular body 18. In this embodiment, all cables 90 are enclosed entirely in their radial direction by channels 132. So, if, as caused by an increased tension of cables 90 in a deflected zone 17 of the tubular body 18, cables 90 will experience radial forces as seen from their own central axis, they will not experience increased friction or get stuck in tapered portions of the channels 132 because of a wedge effect but will always remain fully supported by channels 132.

[00114] An alternative outer tube element 130 may be designed such that it defines an open channel 132 towards central axis 98. These channels 132 together with the inner surfaces of the inner U- shaped portions 88a1 define channels for accommodating cables 90. Stated differently, then, outer tube element 130 is provided with a plurality of rims, two per cable 80, and aligned with the channels

132. Each pair of such rims then supports one cable 90 at both sides along their entire length.

[00115] Cables 90 can be fixed to outer tube element in ways known from the prior art, e.g. by providing their most distal ends with a thicker section which is much thicker than the channel cross section. This can e.g. be done by clamping a bead like element or crimp bushings on the most distal end of the cables 90 which remains clamped after the clamping action.

[00116] Intermediate tube element 88a has a corrugated cross section. In the embodiment shown, it has six outer portions 88a2 designed such that they are arranged on a circle and six inner portions 8841 having a U-shape. Any other number than six may be applied to. Each U-shaped inner portion 88a1 connects two adjacent outer portions 88a2. The inner side of outer tube element 130 is shaped to match the outer surface of intermediate tube element 88a. Channels 132 are located in inwardly extending portions of outer tube element 130 which are at least partly arranged within the U-shaped inner portions 88a1 of intermediate tube element 88a. By this corrugated structure, intermediate 40 tube element 88a supports outer tube element 130 and counteracts deformation of outer tube

P8077901NL4 -18- element 130 by radial forces (caused by bending of the tubular body 18) or tangential forces (caused, e.g., by rotating the tubular body 18 at the proximal end in use). Thus, even when the tubular body 18 is bent and rotated it will keep its original cross section shape as much as possible and so do channels 132. Consequently, cables 90 do not get stuck in use.

[00117] Outer tube element 130 is preferably made from a flexible plastic, like polymer, that shows a predetermined rotational stiffness, longitudinal stiffness, and manufacturability. Such a tube element can be designed flexible and yet rigid enough such that it can be deflected in deflectable zone 17 and is flexible in flexible zone 12a. It can be made by extrusion, 3D printing, etc. Preferably, the material has an as low as possible friction coefficient relative to cables 90, a material like UHMWPE and/or Teflon™

[00118] The thickness of outer tube element 130 depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The inner and outer diameters of the outer tube element 130 depend on its application. For medical applications the inner and outer diameters may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm. The thickness of outer tube element 130 at locations between channels 132 may be in a range of 0.02-

2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The thickness of outer tube element 130 at locations including channels 132 may be 0.1 mm. Channels 132 have a diameter slightly larger than cables 90, so, for instance, in a range of 0.1 mm

1.0 mm.

[00119] Intermediate tube element 88a is provided with a deflectable section in deflectable zone 17 and a flexible section in flexible zone 12a. Any suitable technical implementation can be used. E.g., slotted structures like the ones shown at 72 and 74 in the outer tube element 86 of the embodiment of Figures 5A-5C or 6A-6C can be used. Alternatively, the slotted structure 106 as shown in corrugated intermediate tube element 88 of Figure 7A can be used. A possible implementation is shown in Figures 14A, 14B.

[00120] Intermediate tube element 88a has, preferably, a uniform thickness and is made from a metal to meet the requirements as to rotational stiffness, longitudinal stiffness, play and manufacturability of the tubular body 18. Suitable materials are steel alloys like stainless steel, cobalt-chromium alloys or a shape memory alloy such as Nitinol®. Intermediate tube element 88a can be made by shaping an originally cylindrical tube with circular cross section into the desired form. Preferably, the material has an as low as possible friction coefficient relative to cables 90.

[00121] The thickness of intermediate tube element 88a depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The inner and outer diameters, respectively, of the intermediate tube element 88a, as defined by most inner points ofthe U-shaped inner portion 88a1 and outer portion 88a2, respectively, depend on its application. For medical applications the inner and outer diameters may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm. 40 [00122] Even though the intermediate tube element 88a has a corrugated cross section,

P8077901NL4 -19- experiments have shown that the slots of the slotted structure 106 in intermediate tube element 88a can be made by laser cutting with a laser beam which may be directed in a plane perpendicular to the central axis 98 and either perpendicular to the central axis 98 or perpendicular to the outside surface of intermediate tube element 88a. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 um.

[00123] Also here cables 90 may have a thickness of 0.1 to 1.0 mm.

[00124] The embodiment shown in Figures 9A and 9B is an alternative to the one of Figures 8A- 8C. Figure 9B is a cross section view as defined by arrows IXB in Figure 9A. Here, the tubular body 18 comprises an outer tube element 134 that has a uniform thickness. Outer tube element 134 encloses intermediate tube element 88a. Instead of intermediate tube element 88a, alternatively, intermediate tube element 88 may be used or another suitable form.

[00125] Outer tube element 134 may be made from any suitable material as long as it meets the requirements as to rotational stiffness, longitudinal stiffness, and manufacturability, as well as deflectability in deflectable zone 17 and flexibility in flexible zone 12a.

[00126] In the embodiment shown in Figures 9A and 9B outer tube element 134 is similar to the outer tube element 86 of Figures 5A-5C. However, one can use the same outer tube element as shown in Figures 5A-5C, or 6A-6C or 8A-8C instead.

[00127] In flexible zone 12a, outer tube element 134 has a flexible section 74 with the same slotted structure as shown in Figure 5A (cf. also Figure 16B). Other slotted structures can be used instead.

[00128] In deflectable zone 17, outer tube element 134 has a deflectable section 72 with a slotted structure as shown in more detail in Figure 16D. Other slotted structures can be used instead.

[00129] In the tip section, distal to deflectable zone 17, outer tube element 134 comprises non- flexible section 78 which is preferably a ring shaped portion of outer tube element 134 that has no, or hardly any holes or slots in it such that it cannot be bent. Distal from non-flexible section 78 and connected / attached to it, outer tube element 134 is provided with strips 138 defining slots 139 between them. At their distal ends, the strips 138 are all connected / attached to a non-flexible section 140 which is preferably also a ring shaped portion of outer tube element 134 that has no, or hardly any holes or slots in it such that it cannot be bent. Preferably, there are as many strips 138 as there are outer portions 88a2 of intermediate tube element 88a. And, preferably, each strip 138 is attached or connected to one such outer portion 88a2, e.g., by laser welding, gluing or brazing or a bent lip/opening connection.

[00130] Outer tube element 134 is also attached to intermediate tube element 88a at welding lips

75. Each welding lip 75 is welded to one outer portion 88a2 of intermediate tube element 88a. Also at other locations along flexible zone 12a, outer tube element 134 may be attached to intermediate tube element 88a, e.g. by gluing or brazing, or laser welding suitable welding lips to outer portions 88a2, or bent lip/opening connections.

[00131] Outer tube element 134 is preferably made from a metal. Suitable materials are steel alloys like stainless steel, cobalt-chromium alloys, or a shape memory alloy such as Nitinol®. However, any other material that can meet the requirements as to rotational stiffness, longitudinal stiffness, 40 play and manufacturability as regards the above explained slots / slotted structures can be selected

P8077901NL4 -20- too, like plastic, polymer, composites or other cutable material in which hinges can be made.

[00132]The thickness of outer tube element 134, which is preferably uniform, depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably

0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of the outer tube element 134 depends on its application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm.

[00133] The slots of the slotted structures 72, 74 in outer tube element 134 can be made by laser cutting. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 um.

[00134]Inner U-shaped portions 88a1 enclose channels 96 (cf. also Figure 5B). Again, these channels 96 may be straight or spiraled in the longitudinal direction of tubular body 18. In this embodiment, each channel 96 accommodates a liner 142. The outer surface of liner 142 has a first portion directed outwardly as seen from central axis 98 which has a shape matching the inside surface of outer tube element 134. So, the first portion has the form of a portion of a circle. The outer surface of liner 142 has a second portion directed inwardly as seen from central axis 98 which has a shape matching the inside surface of inner U-shaped portion 88a1. Thus, each liner 142 is firmly supported at all sides by either the inside surface of an inner U-shaped portion 8841 or the inside surface of outer tube element 134. Moreover, each liner 142 fills the tapered section 99 of channel 96 where outer portion 88a2 touches outer tube element 134.

[00135]Each liner 142 is provided with an internal channel 144 extending in the longitudinal direction and accommodating a cable 90.

[00136] An alternative liner 142 may be designed such that it defines an open channel 144 towards central axis 98. These open channels 144 together with the inner surfaces of the inner U-shaped portions 8841 define channels for accommodating cables 90. The inner surface of open channels 144 has a shape of a portion of a circle to support a cable 90.

[00137]Liner 142 may, as a further alternative be implemented by a wire shaped element. Such a wire shaped element met have a circular, oval, triangular, etc. shaped cross section.

[00138]Liner 142 may be made from a flexible plastic, like polymer, that shows a predetermined rotational stiffness, longitudinal stiffness, and manufacturability. Alternatively, it can be made from a metal, e.g. one of the metals mentioned above. It can be made by extrusion, 3D printing, etc. Preferably, the material has an as low as possible friction coefficient relative to cables 90. UHMWPE and/or Teflon™. Its dimensions are such that they match those of the selected cable 90, intermediate tube element 88a and outer tube element 134.

[00139]Due to its corrugated structure, intermediate tube element 88a counteracts its own deformation by radial forces (caused by bending of the tubular body 18) or tangential forces (caused, e.g., by rotating the tubular body 18 at the proximal end in use). Thus, channels 96 defined by the inner U-shaped portions 88a1 keep their form even when the tubular body 18 is bent / deflected along its length at several locations. The liners 142 being located in these channels 96 will, therefore, also keep their form when the tubular body 18 is bent / deflected along its length, as 40 will the channels 144 defined within liners 142 or will the channels defined between open channels

P8077901NL4 -21- 144 and channels 96 accommodating the cables 90. Moreover, the tapered portions of channels 96 at locations where outer portions 88a2 touch outer tube element 134 are now filled with liners

142. Consequently, cables 90 do not experience increased friction or get stuck in these tapered portions in use.

[00140]In the embodiment of Figures 9A, 9B at least one of outer tube element 134 and intermediate tube element 88a is made from a metal like stainless steel, cobalt-chromium alloy, or a shape memory alloy such as Nitinol®.

[00141]Figure 9C shows an alternative solution to the one of Figures 9A and 9B. The intermediate tube element 88a is the same as the one of Figures 9A and 9B. However, an alternative outer tube element 135 is applied. Outer tube element 135 is provided with a plurality of rims 141, one rim 141 per cable channel 96. Each rim 141 extends to a certain predetermined extent in an open portion of one cable channel 96 facing away from central axis 98. Moreover, each rim 141 extends along the entire length of outer tube element 135. Each two adjacent rims 141 are mutually connected via outer tube element portions 137 all located on a same circle about central axis 98, such that intermediate tube element portions 88a2 are aligned with outer tube element portions 137 such that one intermediate tube element portion 88a2 touches one outer tube element portion 137.

[00142] There may be small tapered sections 99 of cable channel 96 between outer tube element 135 and intermediate tube element 88a, as indicated in Figure 9C. However, because rims 141 extend slightly into channels 96 and support cables 90, risks for cables 90 to experience increased friction or get stuck in these tapered sections 99 are reduced.

[00143] For the rest, the same properties may apply to outer tube element 135 as to outer tube element 134 (or 86).

[00144] In the embodiment of Figure 9C at least one of outer tube element 135 and intermediate tube element 88a is made from a metal like stainless steel, cobalt-chromium alloy, or a shape memory alloy such as Nitinol®. They are attached to one another at predetermined locations along their length to provide the tubular body with enough rotational and longitudinal stiffness.

[00145] Figure 10A shows a further embodiment of the invention. It has the same outer tube element 134 as the embodiment of Figures 9A, 8B. However, intermediate tube element 88b has a different shape. l.e., intermediate tube element 88b has, in general, both an internal and external circular cross section and a uniform thickness but has a plurality, here six, of channels 96a arranged in its outside surface. They have a shape of an open U, the open end of which is facing outward as seen from central axis 98. Each one of them accommodates a cable 90. At their internal sides, the U- shaped channels, preferably, have the form of half a circle to properly support a cable 90. Towards the outer surface of intermediate tube element 88b, U-shaped channels 96a have walls with a planar cross section oriented perpendicular to the outside surface. Deviations of up to +/- 10%, preferably less than +/- 5%, from such a 90° orientation may be acceptable.

[00146] Between the channels 96a, intermediate tube element 88b has outer surface portions 88b1 having a circular shape which, in the assembled state of the tubular body 18, touches the inside surface of outer tube element 134. Outer surface portions 88b1 are attached at predetermined 40 locations to outer tube element 134 in the same way, e.g. by means of gluing or brazing or lips, as

P8077901NL4 -22- are outer portions 88a2 in the embodiment of Figures 9A, 9B.

[00147] The channels 96a may be straight or spiral along the length of the tubular body 18.

[00148] Intermediate tube element 88b is provided with a deflectable section in deflectable zone 17 and a flexible section in flexible zone 12a. Any suitable technical implementation can be used. E.g., slotted structures like the ones shown at 72 and 74 in the outer tube element 86 of the embodiment of Figures 5A-5C or 6A-6C can be used. Alternatively, the slotted structure 106 as shown in corrugated intermediate tube element 88 of Figure 7A can be used.

[00149] Intermediate tube element 88b has, preferably, a uniform thickness and is preferably made from a metal. Suitable materials are steel alloys like stainless steel, cobalt-chromium alloys, or a shape memory alloy such as Nitinol®. However, any other material that can meet the requirements as to rotational stiffness, longitudinal stiffness, play and manufacturability as regards the above explained slots / slotted structures can be selected too. Preferably, the material has an as low as possible friction coefficient relative to cables 90. a material like UHMWPE and/or Teflon™.

[00150] The thickness of intermediate tube element 88b depends on its application. For medical applications the thickness in locations without channels 96a may be in a range of 0.3 — 1.5 mm, preferably 0.4 — 0.8 mm, more preferably 0.5 — 0.7 mm.

[00151] Even though, due the channels 96a, intermediate tube element 88b has a cross section with varying thickness, experiments have shown that the slots of slotted structures, like 72, 74, 108, 136 in intermediate tube element 88b can be made by laser cutting with a laser beam substantially directed perpendicular to the central axis 98. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 um.

[00152] Channels 96a can be made in intermediate tube element 88b by means of laser engraving a metal tube element by a laser beam directed perpendicular to its outside surface. An advantage of intermediate tube element 88b is that the slotted structures and channels 96a can be made in one single process with the same laser machine resulting in an intermediate tube element 88b that can be produced at reasonable costs and high reliability. Other techniques may be used instead. E.g., 3D laser printing may be used, or intermediate tube element 88b may be made by extrusion.

[00153] Also here cables 90 may have a thickness of 0.1 to 1.0 mm.

[00154] Due to its essentially circular cross section, intermediate tube element 88b counteracts its own deformation by radial forces (caused by bending of the tubular body 18) or tangential forces (caused, e.g., by rotating the tubular body 18 at the proximal end in use). Moreover, at locations without channels 96a, the thickness of intermediate tube element 88b may be rather large which is advantageous for its rotation stiffness, longitudinal stiffness, and the strength of hinges made by slotted structures. This is especially true if intermediate tube element 88b is made from metal. Thus, channels 96a defined by the U-shaped channels 96a keep their form even when the tubular body 18 is bent / deflected along its length at several locations. Moreover, the channels 96a do not have tapered portions at locations where U-shaped channels 96a meet outer portions 88b1. Consequently, cables 90 do not experience increased friction or get stuck in a transition area from U-shaped channels 96a to outer portions 88b1. 40 [00155] It will be understood by persons skilled in the art that channels 96a may be provided on the

P8077901NL4 -23- inside surface of intermediate tube element 88b1 instead of, or in addition to on the outside surface. If applied on its inside surface, inner tube element 92 should be applied too.

[00156] In the embodiment of Figure 10A at least one of outer tube element 134 and intermediate tube element 88b is made from a metal like stainless steel, cobalt-chromium alloy, or a shape memory alloy such as Nitinol®. They are attached to one another at predetermined locations along their length to provide the tubular body with enough rotational and longitudinal stiffness.

[00157] Figure 10B shows a further alternative embodiment. Here, inner tube element 88c has a plurality of, here six, channels 96b in its outside surface having a cross section of half a circle, as defined by outer portions 88c1. In between these outer portions 8801, intermediate tube element 88c has outer portions 88c2 having comparable or identical cross sections as outer portions 88b1 shown in Figure 10A. For the rest, intermediate tube element 88c may be identical to intermediate tube element 88b of Figure 10A. Channels 96b may be formed such that their cross sections form a smaller portion or larger portion of a circle.

[00158] In Figure 10B, outer tube element 134a has an essentially uniform thickness but is provided with a plurality of, here six, channels 148 in its inside surface having a cross section of, preferably, half a circle, as defined by inner portions 134a1. In between these inner portions 134a1, outer tube element 134 has outer portions 134a2 having circular cross sections. Channels 148 may be longitudinal slots formed in the inside surface of outer tube element 134a. For the rest, outer tube element 134 may be identical to outer tube element 134 of Figure 10A. Channels 148 may be formed such that their cross sections form a smaller portion or larger portion of a circle, as long as one channel 96b with its counterpart channel 148 together form one channel 146 with a circular cross section. Outer tube element 134a is, e.g., made from plastic and may be manufactured by extrusion or 3D printing techniques.

[00159] Together, one channel 96b and one channel 148 forms one channel 146 with a circular cross section accommodating one cable 90 (not shown in Figure 10B). Other cross sections than circular may be applied as well. Each such channel 146 may be straight or spiral in the longitudinal direction of tubular body 18.

[00160] The structure of Figure 10B may be designed such as to have the same advantages as the one of Figure 10A, as regards longitudinal stiffness and rotational stiffness. Channels 96b can be made in intermediate tube element 88c by means of laser engraving a metal tube element by a laser beam directed perpendicular to its outside surface. An advantage of intermediate tube element 88c is that the slotted structures and channels 96b can be made in one single process with the same laser machine resulting in an intermediate tube element 88c that can be produced at reasonable costs and high reliability. Other techniques may be used instead. E.g., 3D laser printing may be used, or intermediate tube element 88b may be made by extrusion.

[00161] In the embodiment of Figure 10B at least one of outer tube element 134a and intermediate tube element 88c is made from a metal like stainless steel, cobalt-chromium alloy, or a shape memory alloy such as Nitinol®. They are attached to one another at predetermined locations along their length to provide the tubular body with enough rotational and longitudinal stiffness. 40 [00162] Figures 11A, 11B, 11C, 11D, 11E, 11F show embodiments in which cables 90 are blocked

P8077901NL4 -24- from tangential movements by other tangential blockers than an intermediate tube element. Figure 11B shows a cross section through the embodiment of Figure 11A perpendicular to the central axis 98 as indicated by arrows XIB in Figure 11A. Figure 11D shows a cross section through the embodiment of Figure 11C perpendicular to the central axis 98 as indicated by arrows XID in Figure 11B. Figure 11F shows a cross section through the embodiment of Figure 11E perpendicular to the central axis 98 as indicated by arrows XIF in Figure 11E.

[00163] In the embodiment of Figures 11A, 11B outer tube element 134 is the same as in in Figure 9A. As shown, in the embodiment of Figures 11A and 11B, strips 138 are implemented as two different types, i.e., alternating strips 138a and 138b. Strip 138a is designed such that, at its distal end, it is attached to ring-shaped portion 140. At its proximal end 145, strip 138a is disconnected from ring-shaped portion 78. Moreover, proximal end 145 may be provided with an additional lip

147. Adjacent to strip 138a, at both sides, strips 138b are present which are at both their distal end and proximal end, respectively, attached to ring-shaped portion 140 and ring-shaped portion 78, respectively. In the shown embodiment there are three strips 138a and three strips 138b. However, other numbers may be applied.

[00164] The embodiment has six adjacent cables 90 (other numbers may be applied). Each one of them is accommodated in a tube 131. These tubes 131 are flexible and, in an embodiment, contacting both inner tube element 92 and outer tube element 134 such that they are slightly clamped between inner tube element 92 and outer tube element 134. Each one of these tubes 131 has an internal hollow channel accommodating one cable 90. The cross section size of these hollow channels is such that the cable 90 inside them can freely move in the longitudinal direction with as low friction as possible.

[00165] In the longitudinal direction, each one of the tubes 131 with their cables 90 inside may extend completely linearly or spirally to provide the cables 90 with a tangentially rotated location along the body 18, for purposes explained above.

[00166] The cross sectional form of the tubes 131 may be circular, as shown in Figure 11B. However, the invention is not limited to such an implementation. Its cross section may be oval, rectangular, etc. This also applies to the hollow channels within them.

[00167] Tubes 131 may be implemented by coils, e.g. made of metal, extending longitudinally from deflectable zone 17 below strips 138a, 138b, as shown in Figure 11A. The metal may be a steel alloy like stainless steel, cobalt-chromium alloy, Nitinol™; etc. In such a case, each one of the lips 147 of the strips 138b is, preferably, welded to one tube 131. By doing so, at the location of the strips 138a, 138b, the tubes 131 and cables 90 are blocked from tangential rotation relative to outer tube element 134. To block such tangential rotation of tubes 131 and cables 90 relative to outer tube 134 along the entire body 18, tubes 131 are also attached to outer tube element 134 at other locations along the tubular body 18. The number of such attachments depends on the required rotational stiffness, and play, as well as flexibility of the intermediate zone 12a. Moreover, such attachments to outer tube 134 support longitudinal stiffness. So, here, tubes 131 function as tangential rotation blockers for cables 90. 40 [00168] Tubes 131 may, alternatively, be made from a suitable other material including polymers,

P8077901NL4 -25- UHMWPE and/or Teflon™. These material cannot be welded to outer tube element 134. So, other tangential blockers should be applied to prevent tubes 131 from tangential rotation relative to outer tube 134. Such tangential blockers may be implemented by lips arranged at predetermined locations along outer tube element 134 and bent inwardly towards central axis 98 in order to fix the tangential position of tubes 131. An alternative may be that outer tube element 134 is provided with longitudinal rims on its inner surface which may each taper towards central axis 98 and contact two adjacent tubes 131 in order to fix the tangential position of tubes 131. Also inner tube 92 may be provided with such tangential blockers on its outer surface, e.g. in the form of longitudinal rims or extensions at predetermined locations. Such (extra) tangential blockers can also be applied in case tubes 131 are made from a metal.

[00169] It is observed that the embodiment where outer tube element 134 has such rims on its inner surface corresponds to the alternative embodiment explained with reference to Figures 8A-8C where alternative outer tube element 130 is designed such that it defines an open channel 132 towards central axis 98.

[00170] Cables 90 may be provided with crimp bushings like crimp bushings 143 (cf. Figures 19A and 19B).

[00171] Figures 11C, 11D show a further alternative embodiment. Here, body 18 comprises outer tube element 134 and inner tube element 92 as explained with reference to earlier figures. It is observed that this embodiment is explained with reference to outer tube element 134. However, any other outer tube element, e.g., as explained here can be used instead. Adjacent cables 90 are separated from one another by tangential spacer elements 133. They may be implemented as flexible tubes, flexible and stretchable cables, etc. The flexible tubes 133 may be hollow or solid. They are, preferably, made from a material that provides an as low as possible friction to cables 90, e.g., polymers, UHMWPE and/or Teflon™. However, they can also be made from steel alloys like stainless steel, cobalt-chromium alloys, Nitinol™, etc. They may be made as a coil, as shown in figure 11C. Their main function is to prevent tangential movement/rotation of cables 90 in operation of the instrument. So, the tangential spacer elements 133 should have a minimum stiffness in their cross sectional direction, as determined by the application of the instrument.

[00172] Again, both cables 90 and tangential spacer elements 133 may extend linearly in the longitudinal direction of the body 18 or may spiral to a certain predetermined extent, as explained above.

[00173] The tangential spacer elements 133, if made from a metal, are preferably attached, e.g. by laser welding, to outer tube element 134 or inner tube element 92 at predetermined locations along body 18 to provide a suitable tangential blocking effect to cables 90. Alternatively, or in addition to that outer tube element 134 is provided with tangential blockers to block tangential spacer elements 133 from tangential rotation relative to outer tube 134. Such tangential blockers may be implemented by lips arranged at predetermined locations along outer tube element 134 and bent inwardly towards central axis 98 in order to fix the tangential position of tangential spacer elements

133. An alternative may be that outer tube element 134 is provided with longitudinal rims on its 40 inner surface which may each taper towards central axis 98 and contact adjacent pairs of one cable

P8077901NL4 -26- 90 and one tangential spacer element 133 in order to fix their tangential positions. Also inner tube 92 may be provided with such means on its outer surface, e.g. in the form of longitudinal rims or extensions at predetermined locations.

[00174]In the embodiment of Figures 11A, 11B, 11C, 11D at least one of outer tube element 134 and inner tube element 92 is made from one of the above mentioned metals and attached to tubes 131 / tangential spacers 133.

[00175] Figures 11E, 11F show another embodiment with tangential spacer elements 149. Figures 11E, 11F show a small portion of outer tube element 134. However, any other outer tube element, e.g., as explained here can be used instead. The small portion of outer tube element 134 can be located anywhere along its longitudinal direction.

[00176] Figure 11E shows an exploded 3D view whereas Figure 11F shows a cross section perpendicular to central axis 98 as indicated by arrows XIF in Figure 11E.

[00177] The same embodiment has six cables 90, however, any other desired number may be applied. As explained before, cables 90 may extend linearly or spirally from the proximal end to the distal end of body 18, as explained above. Each pair of adjacent cables 90 is mutually separated by a lip 149 forming the tangential spacer element. Lips 149 may be formed by laser (or water) cutting suitable slots 157 in outer tube element 134. Each lip 149 is attached to the main body of outer tube element 134 by a strip 153. Opposite to the strip 153 the tangential width of each lip 149 may be larger than the tangential width of strip 153. Each lip 149 is bent inwardly such that its inner surface 159 (cf. Figure 11F) contacts inner tube element 92. Because lip 149 is cut from outer tube element 134 its inner surface has a circular shape matching the circular shape of the outer surface of inner tube element 92 which it contacts. There is no strict need to attach lips 149 to inner tube element 92 but one could do so if desired, e.g. by laser welding or gluing or brazing.

[00178] The tangential distance between tangential sides 161 of two adjacent lips 149 is designed such that cables 90 can move freely in the longitudinal direction of the body 18. All lips 149 are bent inwardly to such an extent they also form radial spacers for cables 90. l.e., they establish a radial distance between the outer surface of inner tube element 92 and the inner surface of outer tube element 134 such that cables 90 can move freely in the longitudinal direction of body 18. The radial distance between the outer surface of inner tube element 92 and the inner surface of outer tube element 134 is, e.g., in a range of 2-30% larger, or preferably in a range of 2-15% larger than the diameter of cables 90.

[00179] In an embodiment, the radial distance between the outer surface of inner tube element 92 and the inner surface of outer tube element 134 is slightly larger than the thickness of outer tube element 134 and, thus, of lips 149, e.g., in a range of 2-30% larger, or preferably in a range of 2- 15% larger. However, the invention is not restricted to such embodiments.

[00180] Such sets of lips 149 are applied at predetermined longitudinal distances along outer tube element 134. If cables 90 need to spiral around the body 18, subsequent sets of such lips 149 will be tangentially shifted to provide the desired spiral form.

[00181] In the embodiment of Figures 11E and 11F, outer tube element 134 is preferably made 40 from a suitable metal to facilitate inward bending of the lips 149 and ensure they remain in their

P8077901NL4 -27- inwardly bent position. Suitable materials are steel alloys like stainless steel, cobalt-chromium alloys, or a shape memory alloy such as Nitinol®. Thicknesses of outer and inner tube elements 134, 92 and cables 90 can be the same as in other embodiments.

[00182] In the embodiment of Figure 12, the tubular body 18 has an intermediate tube element 88d and outer tube element 150. Intermediate tube element 88d has a similar cross section as intermediate tube element 88. Its structure is provided with outer portions 88d2 and inner portions 88d1. Inner portions 88d1 have a cross section of a circle portion. Outer portions 88d2 have outside surfaces with a partial circular cross section and touch inside portions 150b of outer tube element

150.

[00183] Outer tube element 150 also has a corrugated cross section. l.e., apart from inner portions 150b, it comprises outer portions 150a. Each outer portion 150a has a cross section of a circle portion and is arranged opposite to one inner portion 88d1. Thus, each outer portion 150a forms a channel 151 opposite to a channel 96 which together form a channel 152 accommodating one cable 90 (not shown in Figure 12).

[00184] Thus, intermediate tube element 88d is designed such as to accommodate only a portion of one cable 90. For the rest, intermediate tube element 88d may have the same structure and features as intermediate tube element 88 or 88a. Intermediate tube element 88d can be made by shaping an originally cylindrical tube with circular cross section into the desired form.

[00185] Outer tube element 150 is designed such as to accommodate a portion of one cable 90.

For the rest, outer tube element 150 may have the same structure and features as outer tube element 86 or 134. Outer tube element 150 can be made by shaping an originally cylindrical tube with circular cross section into the desired form.

[00186] The transitions from inner portions 88d1 to outer portions 88d2 of intermediate tube element 88d may be slightly curved due to the manufacturing process. Similarly, the transitions from inner portions 150b to outer portions 1504 of outer tube element 150 may be slightly curved due to the manufacturing process. Consequently, in the area where an outer portion 88d2 of intermediate tube element 88d meets an inner portion 150b of outer tube element 150, channel 152 may show a small tapered portion which may trigger some stucking effect of cables 90 at locations where tubular body 18 is bent or deflected.

[00187] In order to prevent such potential stucking effect, a flexible tube may be inserted into each channel 152, in which one cable 90 is arranged. This may be a flexible tube like flexible tube 166 shown in Figures 14A, 14B. The flexible tube may be implemented as a flexible coil. Alternatively, a material like liners may be used to fill the tapered portions.

[00188] Inner portions 150b are attached to outer portions 88d2 at predetermined locations in a similar way as outer tube element 134 is attached to outer portions 88a2 of intermediate tube element 88a in Figures 9A, 9B.

[00189] In the embodiment according to Figure 12, at least one of outer tube element 150 and intermediate tube element 88d are made from one of the above mentioned metals.

[00190] The embodiment shown in Figures 13A and 13B has a single intermediate tube element 40 88e. For its proper functioning no outer tube element and/or inner tube element is required. Of

P8077901NL4 -28- course, due to electrical or sterilization requirements a suitable liner (e.g. made of plastic) inside and/or outside intermediate tube element 88e can be provided. Figure 13B is a cross section view as defined by arrows XIIIB in Figure 13A.

[00191] Intermediate tube element 88e made from any of the above mentioned materials to meet the requirements as to rotational stiffness, longitudinal stiffness, and manufacturability, as well as deflectability in deflectable zone 17 and flexibility in flexible zone 12a.

[00192] In flexible zone 12a, intermediate tube element 88e has a flexible section which may be made with a slotted structure as shown in Figure 5A (cf. also Figure 16B). Other slotted structures can be used instead.

[00193] In deflectable zone 17, intermediate tube element 88e has a deflectable section 156 with a slotted structure as shown in more detail in Figure 16D. Other slotted structures can be used instead.

[00194] In the tip section, distal to deflectable zone 17, intermediate tube element 88e comprises a non-flexible section 164 which is preferably a ring shaped portion of intermediate tube element 88e that has no, or hardly any holes or slots in it such that it cannot be bent. Distal from non-flexible section 164 and connected / attached to it, intermediate tube element 88e is provided with strips 160 defining slots 158 between them. At their distal ends, the strips 160 are all connected / attached to a non-flexible section 162 which is preferably also a ring shaped portion of intermediate tube element 88e that has no, or hardly any holes or slots in it such that it cannot be bent. Preferably, there are as many strips 160 and slots 158 as there are cables 90.

[00195] Intermediate tube element 88e has a corrugated cross section. It is provided with outer portions 88e2 and inner portions 88e1. Outer portions 88e2 define the outer circumference of intermediate tube element 88e and may be located on a circle. Adjacent outer portions 88e2 are connected to one another by means of one inner portion 88e1. Inner portions 88e1 have a cross section of almost an entire circle. l.e., at locations where inner portions 88e1 meet outer portions 88e2, inner portion 88e1 has opposing sides touching one another such as to form an essentially closed channel 96. Each channel 96 accommodates one cable 90 and may be straight or spiraled in the longitudinal direction.

[00196] The transitions from inner portions 88e1 to outer portions 88e2 of intermediate tube element 88e may be slightly curved due to the manufacturing process. Consequently, in the area where two opposing sides of inner portion 88e1 touch each other, channel 96 may show a small tapered portion which may trigger some stucking effect of cables 90 at locations where tubular body 18 is bent or deflected.

[00197] In order to prevent such potential stucking effect, a flexible tube may be inserted into each channel 96, in which one cable 90 is arranged. This may be a flexible tube like flexible tube 166 shown in Figures 14A, 14B. Alternatively, some form of liner may be used to fill up the tapered portion. The flexible tube may be implemented as a flexible coil.

[00198] The thickness of intermediate tube element 88e, which is preferably uniform, depends on its application. For medical applications the thickness may be in a range of 0.02-2.0 mm, preferably 40 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of the

P8077901NL4 -29- intermediate tube element 88e depends on its application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm.

[00199] The slots of the slotted structure 156 in intermediate tube element 88e can be made by laser cutting as indicated above. These slots which are made to just separate adjacent elements may have a width, preferably, in a range of 0-50 um, more preferably 0-30 pm.

[00200]Due to its corrugated structure, intermediate tube element 88a counteracts its own deformation by radial forces (caused by bending of the tubular body 18) or tangential forces (caused, e.g., by rotating the tubular body 18 at the proximal end in use). Thus, channels 96 defined by the inner U-shaped portions 88e1 keep their form even when the tubular body 18 is bent / deflected along its length at several locations.

[00201] Figures 14A, 14B show intermediate tube element 88a of Figures 8A, 8B, 8C, 9A, 9B once more. Whereas Figures 8A-8C show a specially designed outer tube element 130 and Figures 9A, 9B show specially designed liners 142 to prevent cables 90 from being stuck in tapering areas of channel 96. Figures 14A, 14B show an alternative solution. l.e., in the embodiment of Figures 14A, 14B an extra tube 166 is provided in each channel 96. Each such tube 166 accommodates one cable 90.

[00202] Tubes 166 are made from a suitable material and have a suitable thickness such that they meet certain predetermined requirements as to longitudinal and radial stiffness, as well as friction with cables 90. An example is Ultra High Density Polyethylene. Due to its low friction, such a material would also simplify inserting the cables 90 into the channels of intermediate tube element once ready. The tube 166 can be made strong and yet flexible enough to allow deflectable zone 17 and flexible section 12a to deflect/ bend in use with acceptable forces, while still essentially keeping their cross section shape.

[00203] In the embodiment shown in Figure 14A, intermediate tube element 88a is provided with deflectable section 106 with a same slotted structure as the one applied in intermediate tube element 88 of Figure 7A.

[00204] Tubes 166 have a circular cross section and have, preferably a uniform thickness. They may be made of a suitable plastic like polymer. Alternatively, they may be made from steel alloys like stainless steel, cobalt-chromium alloys, or a shape memory alloy such as Nitinol®. If desired, tubes 166 may be provided with slotted structures to increase their flexibility. For medical applications, a typical thickness may be in a range of 0.05 — 0.5 mm, preferably 0.05 — 0.3 mm.

[00205] The extra tubes 166 can be used themselves as a elements that control a function of the steerable instrument at its distal end as controlled by a suitable steering member at the proximal end.

[00206] Figures 15A, 15B show an implementation example of the proximal end of the steerable instrument. Figure 15B shows a cross sectional view of the structure shown in Figure 15A.

[00207] At its proximal end, cables 90 may be controlled, i.e. pulled, by any suitable steering mechanism. Such steering mechanism may, for instance, be a proximally arranged deflectable zone like distally arranged deflectable zone 17 and attached in a suitable way to cables 90. Alternatively, 40 the proximal steering mechanism may be implemented by means of a robot. As a further example,

P8077901NL4 -30- the proximal steering mechanism may be implemented as a steering device 168 with a ball-shaped steering device 180. Such a steering device 168 may have any suitable design. An example is shown in Figures 15A, 15B.

[00208] Steering device 168 comprises a housing 169. Housing 169 tapers towards its distal end and increases in diameter towards its proximal end. In an example, housing 169 has a conical shape which is symmetrical about a central axis. Housing 169 encloses a hollow space 171 and is open both to its distal end and proximal end.

[00209] At its distal end, hollow space 171 ends in a channel accommodating a proximal end portion of tubular body 18. At its proximal end, housing 169 is connected/attached to a supporting member

172. Supporting member 172 has a channel 173 at its central axis which accommodates the most proximal end of tubular member 18. A clamping ring shaped element 187 surrounds tubular body 18 within channel 173 such as to clamp tubular body 18 within channel 173. Tubular body 18 can be attached to supporting member 172 in any other way such that it extends for the distal end of supporting member 172 along the central axis if housing 169. In an embodiment, housing 189 is not applied.

[00210] Supporting member 172 has a hollow space 174 towards its proximal end. Inside this hollows space 174, supporting member 172 comprises a pin-shaped member 176 extending in the proximal direction. At its most proximal end, pin-shaped member 1786 is provided with a ball-shaped member 181 with a ball-shaped outer surface. Channel 173 extends through this pin-shaped member 176 and ball-shaped member 181 along a central axis of supporting member 172. Inside ball-shape member 181, channel 173 has an increasing diameter towards the proximal end such as to define a conical space 177.

[00211] Supporting member 172 supports a ball-shaped steering member 180. Steering member 180 has a, partially, ball-shaped outer surface which is symmetrical about a central axis of the ball- shaped steering member 180 and supported by a suitably designed proximal inner surface portion of supporting member 172. Ball shaped steering member 180 has a ball-shaped inner surface 182 supported by ball-shaped member 181 of supporting member 172.

[00212] Hollow space 174 is designed such that ball-shaped steering member 180 can rotate about ball-shaped member 181 towards and away from the central axis of supporting member 172 such that the central axis of ball-shaped steering member 180 deflects from the central axis of supporting member 172 in any desired direction. In an embodiment, the ball-shaped steering member 180 and supporting member 172 are arranged such that if ball-shaped steering member 180 is rotated in the tangential direction about its central axis also supporting member 172 and housing 169 are forced to rotate about their central axes together with tubular body 18. This can, e.g., be implemented by providing ball-shaped member 180 and supporting member 172 with suitable cooperating slots and ribs/pins.

[00213] At its proximal side, ball-shaped member 180 is provided with a cable fastening mechanism

175. In the embodiment shown, the cable fastening mechanism 175 comprises a flange with a plurality of slots. Each slot accommodates and clamps a proximal end of one cable 90. This can be 40 done in several ways known from the prior art. There are no limitations as to the specific

P8077901NL4 -31- implementation. Other structures than a flange 175 can be implemented to provide this clamping effect.

[00214] As shown in Figure 15B, channel 173 in ball-shaped 181 widens towards its proximal end and defines a conically shaped space 177 towards the proximal end.

[00215] At its central axis, ball-shaped member 180 has a channel 179 accommodating a distal end of a hollow tube 183. Proximal end of hollow tube 183 is accommodated by a rotation element like a knob 185. Hollow tube 183 is connected to ball-shaped member 180 and to knob 185 such that when knob 185 is rotated about its central axis, also hollow tube 183 and ball-shaped member 180 are rotated about their central axes. Thus, rotating knob 185 causes the whole steering device 168 to rotate with the same angular amount. The same applies to tubular body 18 since tubular body 18 is fixed or clamped to supporting member 172 by clamping ring shaped element 187.

[00216]Internally, knob 185 has a hollow space accommodating cable fastening member 189 attached to a proximal end of actuation cable 184. Actuation cable 184 extends through hollow tube 183, channel 179 of ball-shaped member 180, channel 173 of supporting member 172 and elongated channel 94 of tubular body 18 towards its most distal end. At the most distal end of tubular body 18, actuation cable 184 is connected or attached to a tool such that longitudinal movement of actuation cable 184 operates the tool, e.g. jaws of forceps 2. This is known to persons skilled in the art and needs no further explanation here.

[00217] When ball-shaped member 180 rotates such that its central axis is deflected from the central axis of supporting member 172 actuation cable 184 can also deflect within ball-shaped member 181 because of the conically shaped space 177 through which actuation cable 184 extends.

[00218] Handle 3 is shown to comprise a rotation knob 186 and two jaws 190 which can be operated by two fingers of a hand. The rotation knob 186 is connected to rotation knob 185, e.g., by a screw thread or bayonet connection. l.e., rotation knob 185 is forced to rotate by rotating rotation knob 186 while, then, the rest of the handle 3 keeps its orientation.

[00219] Handle 3 comprises an actuation rod 188 which, in the shown embodiment, can be clicked on cable fastening member 189 such that any longitudinal movement of actuation rod 188 translates into a longitudinal movement of cable fastening member 189, and therefore of actuation cable 184. Actuation rod 188 itself is operated by grips 190. The invention is not limited to the handle as shown in Figures 15A and 15B. Other suitable handles known from the art may be applied as well.

[00220]Instead of to a handle 3, proximal end of hollow tube 183 may be connected or attached to another device, e.g., when the longitudinal channel 94 is not used for accommodating actuation cable 184 but for other purposes. For instance, longitudinal channel 94 may accommodate an electrical cable for supplying electrical current to an electrical tool at the distal end of the tubular body 18, or a gas and/or liquid tight tube for supplying or draining a gas and or a liquid.

[00221] An operator of the handle 3 may perform the following actions.

[00222] With two fingers the operator can operate the grips 190 such as to longitudinally move actuation cable 184 which then actuates tool 2 at the distal end of tubular body 18. 40 [00223] The operator can rotate rotation knob 186 and thereby rotate the whole steering device 168

P8077901NL4 -32- and tubular body 18. In the embodiment shown, also actuation cable 184 will then rotate while cable fastening member 189 then rotates relative to actuation rod 188, thus allowing the jaws 190 to keep their orientation. Such rotation of the tubular body 18 is transferred to the distal end of the tubular body 18 even about portions of tubular body 18 which are bent / deflected in use, as is apparent to persons skilled in the art. The tool 2 at the distal end of the tubular body 18 is attached or connected to the tubular body 18 in such a way as to rotate together with the tubular body 18. Thus, the tool can be rotated by rotating knobs 185, 186. Of, course, if desired other rotation mechanisms may be used like a flexible rod extending from knobs 185, 186 to the tool at the distal end. Such a flexible rod can be a hollow tube. Instead of two knobs 185, 186 one knob may be used. The knob or knobs may be located at other places on handle 3.

[00224] The operator can deflect hollow tube 183 from the central axis of tubular body 18, as indicated with two arrows 192a, 192b which then rotates ball-shaped member 180 about a point of rotation as defined by a center point of ball-shaped member 181. By this rotation some of the cables 90 which are connected to a portion of flange 175 moving to the proximal direction of the instrument are pulled whereas other cables 90 which are moving in the distal direction are relaxed. As is evident to persons skilled in the art, this translates into some cables 90 moving to the proximal direction which then cause a bending / deflection of deflectable zone 17 of the tubular body 18, connected at the distal end to these cables 90. Preferably, there are three or more cables 80 which are equally distributed tangentially such that deflectable zone 17 can be deflected in all directions.

[00225] In the situation shown, cables 90 are connected at locations on flange 175 which are at a larger distance from the central axis of tubular body 18 than are points of connection of the cables 90 at the deflectable zone 17.

[00226] Now some examples of slotted structures that may be used in deflectable / flexible sections of outer, intermediate and/or inner tube elements will be explained in more detail with reference to Figures 16A-16D. Several of these deflectable / flexible sections have been shown and explained in great detail in WO2018/067004. Also the other slotted structures of WO2018/067004 may be used here. It is observed that here the term “slotted structure” refers to a structure with one or more slots that extend through the entire thickness of the material.

[00227] Figure 16A shows slotted structure 72 in more detail. This slotted structure 72 comprises, as shown at the left hand side, a circumferential slot 73 in the tube element. Slot 73 extends circumferentially.

[00228] Slot 73 has two opposing side walls both extending circumferentially. Slot 73 has a curved slot 85 extending longitudinally, here in the distal direction, from one such side wall and formed as a channel along a portion of a circle having a center point 83. A lip 87 that is shaped as a portion of a circle and matches the form of the curved slot 85 extends from the opposing side wall into this curved slot 85.

[00229] Slot 73 has a further curved slot 81 extending longitudinally, here in the distal direction, from one side wall and formed as a channel along a portion of the same circle along which curved slot 85 extends. A lip 79 that is shaped as a portion of a circle and matches the form of the curved 40 slot 81 extends from the opposing side wall into this curved slot 81.

P8077901NL4 -33-

[00230] Symmetrically located between lips 87, 79 the slotted structure comprises a convex section 77 with a circular outside surface that abuts an oppositely located concave circular section 75. Convex section 77 and concave section 75 have matching circular outside surfaces such that convex section 77 can rotate in concave section 75.

[00231] At the other side of the tube element 180° rotated away, the slotted structure has an identical shape with two further lips and mating convex and concave sections. Thus, two portions of the tube element at either side of the slot 73 can “rotate” relative to one another about two center points 83, such that they deflect relative to one another. The lips 79, 87 move in the curved slots 81, 85 during such rotation and provide no extra friction. The lips 79, 87 provide extra tangential stability to the tube element when one rotates the entire tube element about its central axis. This is an important aid in increasing torque stiffness. They define a predetermined tangential play as determined by the width of the slots 81, 85 surrounding the lips 79, 87.

[00232]As shown in Figure 18A, slot 73 between convex section 77 and concave section 75 is interrupted one or more times such that convex section 77 and concave section 75 are connected to one another by one or more small bridges 89. These small bridges 89 operate as “fracture elements” as will be explained in more detail with reference to Figure 18. l.e., these fracture elements 89 are made on purpose when the instrument is manufactured but are so weak that they will break once convex section 77 is rotated relative to concave section 75 with a predetermined force. Before breaking, the fracture elements 89 provide the tube element with a predetermined extra stiffness such that the tube element can be maneuvered more easily when inserting the tube element inside an other tube element or inserting an other tube element in the tube element. Once broken, the fracture elements 89 play no role anymore and convex section 77 can freely rotate in concave section 75.

[00233] At a predetermined longitudinal distance away from slots 73, the tube element comprises an identical slot but then rotated 90° relative to the slot 73. Thus, two further points of rotation are provided at said predetermined longitudinal distance about which the tube element can rotate but then in a direction perpendicular to the direction of rotation allowed by center points 83.

[00234] At a further predetermined longitudinal distance away from slot 73, the structure as defined by slot 73 is again repeated but now identical to the one formed by slot 73. These alternating structures are repeated several times in the longitudinal direction. Thus, the tube element comprises 90° tangentially rotated centers of rotation at predetermined longitudinal distances away from each other allowing the tube element to deflect in all directions.

[00235] Figure 16B shows an embodiment of slotted structure 74, cf. Figures 6A and SA. It has a circumferential slot 243 which comprises an intermediate section 282 and a circumferential slot 245 which comprises an intermediate section 280.

[00236] Figure 16B shows how circumferential slot 245, at one end, ends in a longitudinal slot 219. Opposite to longitudinal slot 219 there is a further longitudinal slot 217. Longitudinal slots 217, 219 define sides of a longitudinal bridge 215.

[00237] At its other end, circumferential slot 245 ends at a location rotated between 90° and 160° 40 away from longitudinal slot 219. Intermediate section 280 comprises a portion with a U-shape. The

P8077901NL4 -34- U-shape is defined by two parallel long sides connected to one another by a base side. Both long sides are curved, preferably such that the curve shape of one long side coincides with a portion of a first circle C1. The second long side has a curve shape preferably coinciding with a portion of a second circle C2. The first and second circles C1 and C2 preferably have a common center point coinciding with the center point of bridge 215. This is implemented as follows.

[00238] The intermediate section 280 is communicatively connected to the circumferential slot 245 via a first curved slot 288. Furthermore, the intermediate section 280 is communicatively connected to the circumferential slot 245 via a second curved slot 290. The first curved slot 288 may have the same or a different length than the second curved slot 290. The first curved slot 288 may be shorter than the second curved slot 290. The first curved slot 288 extends between a first end at the circumferential slot 245 and a second end. The second curved slot 290 extends between a first end at the circumferential slot 245 and a second end wherein the second end of the first curved slot 288 is communicatively connected to the second end of the second curved slot 290 via an intermediate slot 292. The first curved slot 288 and the second curved slot 290 are curved about the bridge 215. le. the concave sides of the first and second curved slots 288, 290 are facing the longitudinal slot 219 of the bridge 215.

[00239] The first curved slot 288 extends between its first end and second end along the first circle C1 wherein the first circle C1 has as a center coinciding with the center point of the bridge 215. The second curved slot 290 extends between its first end and second end along the second circle C2 wherein the second circle C2 has the same center as circle C1.

[00240] Figure 16B shows how circumferential slot 243, at one end, ends in longitudinal slot 217 which, as observed above, forms bridge 215 together with longitudinal slot 219.

[00241] At its other end circumferential slot 243 ends at a location rotated between 90° and 160° away from longitudinal slot 217. Intermediate section 282 comprises a portion with a U-shape. The U-shape is defined by two parallel long sides connected to one another by a base side. Both long sides are curved, preferably such that the curve shape of one long side coincides with a portion of the first circle C1. The second long side has a curve shape preferably coinciding with a portion of the second circle C2. This is implemented as follows.

[00242] The intermediate section 282 is communicatively connected to the circumferential slot 243 via a third curved slot 298. Furthermore, the intermediate section 282 is communicatively connected to the circumferential slot 243 via a fourth curved slot 200. The third curved slot 298 may have the same or a different length than the fourth curved slot 200. The third curved slot 298 may be shorter than the fourth curved slot 200. The third curved slot 298 extends between a first end at the circumferential slot 243 and a second end. The fourth curved slot 200 extends between a first end at the circumferential slot 243 and a second end wherein the second end of the third curved slot 298 is communicatively connected to the second end of the fourth curved slot 200 via an intermediate slot 202. The third curved slot 298 and the fourth curved slot 200 are curved about the bridge 215. l.e., the concave sides of the third and fourth curved slots 298, 200 are facing the longitudinal slot 217 of the bridge 215. 40 [00243] The third curved slot 298 extends between its first end and second end along the first circle

P8077901NL4 -35- C1. The fourth curved slot 200 extends between its first end and second end along the second circle C2.

[00244] Thus, the first intermediate section 280 defines a U-shape enclosing a first lip 286 extending in a first circular direction as defined by circles C1°and C2. The second intermediate section 282 defines a U-shape enclosing a second lip 284 extending in a second circular direction also defined by circles C1 and C2 but then in the opposite direction of the first lip 286.

[00245] Both circumferential slots 243 and 245 extend around the tube element beyond the side of view of Figure 16B, i.e. towards the side of the tube element not visible in Figure 16B.

[00246]. The tube element comprises two further circumferential slots 513 and 549. Circumferential slots 513 and 549, respectively, have an identical shape as circumferential slots 245 and 243, respectively, however, they are rotated 180° about the tube element. Thus, the two further circumferential slots 513 and 549 define a further longitudinal bridge shaped like longitudinal bridge 215 and located exactly 180° rotated relative to longitudinal bridge 215.

[00247] Circumferential slot 513 extends partly in parallel to circumferential slot 243 such that they define a tangential bridge 244. So, both circumferential slots 243 and 513 extend in planes slightly angled relative to a plane perpendicular to the central axis of the tube element. Similarly, circumferential slot 549 extends partly in parallel to circumferential slot 245 such that they define a tangential bridge 246. So, also circumferential slots 245 and 549 extend in planes slightly angled relative to a plane perpendicular to the central axis of the tube element.

[00248] Portions of the tube element at both longitudinal sides of the circumferential slots 243, 245, 513, and 549 can be deflected relative to one another because the center points of longitudinal bridge 215 and the further longitudinal bridge opposite longitudinal bridge 215 operate as rotation points. By such a deflection about the center points of the longitudinal bridges circumferential slots 245 and 549 will close and circumferential slots 243 and 513 will further open, or the other way around depending on the direction of deflection. Because lips 284 and 286 can freely move in circle shaped channels about the same center points they do not or hardly introduce any friction during such deflection.

[00249] Some predetermined distance away from the structure defined by circumferential slots 243, 245, 513, and 549, the tube element comprises an identical structure with four further circumferential slots. Two of these four further circumferential slots 643 and 645, respectively, with curved lips 296 and 294, respectively, are also shown in Figure 16B. These four further circumferential slots 643, 645 are rotated 90° about the tube element relative to the location of circumferential slots 243, 245, 513, and 549. Circumferential slots 643 and 645 define a longitudinal bridge 649 between them.

[00250] Thus, these four further circumferential slots 643, 645 define two further longitudinal bridges (not visible in Figure 16B) having an identical structure as longitudinal bridge 215 and its counterpart at the opposite side of the tube element, but located 90° rotated. These four further circumferential slots 643, 645 form two further points of rotation allowing portions of the tube element at either longitudinal side of them to deflect relative to one another. However, this deflection is in a surface 40 90° rotated relative to a surface of deflection as allowed by circumferential slots 243, 245, 513, and

P8077901NL4 -36-

549. In total, the slotted structure shown in Figure 16B allows a deflection in all directions.

[00251] By adding more of such structures with four circumferential slots at predetermined distances in the longitudinal direction of the tube element a hinge can be provided allowing the tube element to deflect in all directions within a predetermined solid angle.

[00252] It is observed that the tube element with the slotted structure as shown in Figure 16B has an improved torque stiffness. The reason is as follows. First of all, circumferential slots 243, 245, 513, 549, 643, 645 do not extend almost 180° as in some prior art structures and in the structure of Figure 168A.

[00253] Moreover, when a user tries to rotate a tube element as shown in the embodiment of Figure 16B, the pins 284, 286, 294, 296 can only move in the circumferential direction at a maximum distance of one curved slot 288, 290, 298, 200, and will then be blocked from any further circumferential movement as determined by the width of the slot surrounding them. So, the elastic deformation of and tension will never exceed a certain threshold as determined by the design of the intermediate sections 280, 282, 294, 296.

[00254] Also, the tube element shown in Figure 16B has a very good longitudinal stiffness due the longitudinal bridges 215. l.e., none of the circumferential slots 243, 245, 513, 549, 643, 645 extend in a 360° circumferential distance.

[00255] The structure of Figure 16B is less flexible than the structure shown in Figure 18A because the tangential bridges 244, 246 between slots 513, 245/549, 643/645 are elastically deformed during deflection. No such tangential bridges are present in the embodiment of Figure 186A.

[00256] Figure 16C shows an embodiment of slotted structure 106 (cf. Figure 7A and 14A) in a tube element having an alternative bridge 272. Figure 18C shows how circumferential slot 245 ends in a longitudinal slot 219. However, here longitudinal slot 219 is communicatively connected to a longitudinal slot 260 via a curved slot 262 such that they form a U-shaped slot. Circumferential slot 243 ends in a longitudinal slot 217 However, here longitudinal slot 217 is communicatively connected to a longitudinal slot 256 via a curved slot 258 such that they form a U-shaped slot in the longitudinally opposite direction of U-shaped slot 219, 262, 260. Thus, a bridge 272 is present which has a mirrored S-shape. Of course, the shape may alternatively be equal to an S-shape. Alternatively, the shape may be a Z-shape or mirrored Z-shape.

[00257] Slots 243 and 245 do extend in a plane slightly angled relative to a plane perpendicular to the central axis. They extend along an angle < 180°. At a location 180° rotated relative to the bridge 272, there is an identical structure formed by an identical slot structure. A portion of one circumferential slot 513 of that identical structure, defining tangential bridge 244 with circumferential slot 243 is visible in Figure 16C.

[00258] It is observed that slots 243, 245, 513 are extending in planes angled relative to a plane perpendicular to the central axis in a way opposite to the way shown in Figure 16B.

[00259] Two such S-shaped bridges 272 at opposing sides of the tube element form excellent points of rotation such that portions of the tube element at either longitudinal side of the S-shaped bridges 272 can be deflected relative to one another.

40 [00260] The structure can be combined with curved lips like lips 284 and 286 of Figure 16A.

P8077901NL4 -37-

[00261] The slotted structure shown at the right hand side of Figure 16C may be repeated one or more times at predetermined longitudinal distances away and, preferably, each time 90° rotated relative to the adjacent one. One such 90° rotated structure is shown at the left hand side of Figure 16C without further reference signs.

[00262] It is observed that a tube element having S-shaped or Z-shaped bridges 272 as shown in Figure 16C have a much larger bending angle than embodiments with single straight longitudinal bridges like bridges 215 of Figure 16B.

[00263] Figure 16D shows an implementation of slotted structure 156, cf. Figure 13A. It is identical to the one shown in Figure 16B apart from the lips 284, 286, 294, 296. Figure 16D is oriented such that its view is partly inside the tube element such as to show the 3D, tangentially symmetrical structure of the slotted structure. Similar tangentially symmetries apply to the slotted structures of Figures 18A,. 16B, 16C.

[00264] The width of slots of the slotted structures 72, 74, 106, 136, 156 can be made very small, i.e. equal to 0 um or very close to that. This is e.g. required in slotted structure 72 where convex section 77 abuts concave section 75 (cf. Figure 16A).

[00265] Figure 18 shows how slot 73 at the location where convex section 77 abuts concave section 75 can be made small while using fracture elements 89. Figure 18 shows an enlarged portion of the slotted structure 72 shown in Figure 18A directly after its manufacturing. It shows that convex section 77 is, then, still attached to concave section 75 by means of a plurality of fracture elements

89. Moreover, lips 87 and 79 are still attached to the opposing part of the tube element by means of one or more fracture elements 89.

[00266] Such fracture elements 89 can be made as follows. Slot 73 is made by directing a laser beam with a predetermined energy and width to the tube element such as to cut through the entire thickness of the tube element. The laser beam moves relative to the tube element outer surface by moving a laser source relative to that outer surface. However, at locations where fracture elements 89 are to be formed, the laser beam is interrupted for a certain period of time whereas the laser source still moves relative to the tube element outer surface.

[00267] As explained above, when deflecting different portions of slotted structure 72 relative to one another for the first time, these fracture elements 89 will fracture. A great advantage of such fracture elements 89 is that, after being fractured, the distance between two opposite sides of the fracture is substantially O um which results in an extremely low play between them.

[00268] Figures 19A and 19B schematically show how cables 90 can be connected to the tip section by means of crimp bushings. Figure 19A shows a 3D view of such a tip section and Figure 19B shows a front view of the embodiment of Figure 19A. These Figures 19A and 19B show but one possible example of using crimp bushings.

[00269] The tips section as shown in Figure 19A is the one of tubular body 18 as shown in Figure SA and the same reference signs refer to the same elements as in Figure 9A. However, the principle of using crimp bushings can be applied to all other embodiments as well.

[00270] As shown, in the embodiment of Figures 19A and 19B, strips 138 are implemented as two 40 different types, i.e., alternating strips 138a and 138b. Strip 138a is designed such that, at its distal

P8077901NL4 -38- end, it is attached to ring-shaped portion 140. At its proximal end 145, strip 1384 is disconnected from ring-shaped portion 78. Moreover, proximal end 145 may be provided with an additional lip

147. Adjacent to strip 1384, at both sides, strips 138b are present which are at both their distal end and proximal end, respectively, attached to ring-shaped portion 140 and ring-shaped portion 78, respectively.

[00271] Intermediate tube element 88a (not visible in Figure 19A) ends within outer tube element 134 at a location in a plane perpendicular to the central axis 98 coinciding with the most proximal end of slots 139. A crimp bushing 143 is pushed over the distal end of each cable 90 such that each crimp bushing 143 is aligned with one slot 139. Preferably, the arrangement is such that, before the shrinking process, each crimp sleeve 143 partly extends in one slot 139, as is clearly shown in Figure 19B. The diameters of the crimp sleeves 143 are so large that each one of them completely covers one cable channel 96 inclusive of the surrounding intermediate tube element material. So when looking from the front, one can only see portions 88a2 of intermediate tube element 88a (cf. Figure 19B).

[00272] Crimp sleeves 143 are made of a deformable material like any suitable metal. Once pushed over the cables 90, a suitable force is applied to the outer surface of each crimp sleeve 143 to crimp them and clamp each one of them to one of the cables 90. This can advantageously be done while a portion of cable 90 extends beyond the most distal portion of outer tube element 86, 134. Once crimped on cable 90, the other end of cable 90 can be inserted into one of the channels 96, 97 until the cable 90 cannot be inserted any further due to the crimp bushing being stopped by the distal end of channel 96, 97.

[00273] This has been shown in more detail in Figure 19C. Figure 19C is a longitudinal cross section of the distal portion of the instrument shown in Figures 19A, 19B. As Figure 19C shows, the distal end side of intermediate tube element 88a is, viewed in the longitudinal direction, located at the most proximal end of slots 139. Lips 147 are welded to the distal end side of intermediate tube element 88a, i.e, to an outer portion 88a2 thereof. In their operational status, crimp bushings 143 abut the distal end side of intermediate tube element 88a. Moreover, their cross sectional size is such that, in the operational status, their longitudinal direction is, preferably aligned with the longitudinal direction of body 18 whereas, at the same time, each one partly lays in one of the slots

139.

[00274] After being crimped against one cable 90 each crimp bushing 143 will prevent longitudinal movement of its corresponding cable 90 in cable channel 96 in the proximal direction of the steerable instrument. Now, deflectable zone 17 can be deflected by pulling on some of the cables 90 and relaxing opposing ones, as will be evident to persons skilled in the art.

[00275] The method of manufacturing a flexible tube element according to the invention can be summarized as follows: a. providing a tube element 88; 88a; 88b; 88c; 88d; 88e which has an inner surface and an outer surface, said inner surface surrounding a first channel 94, wherein said tube element 88; 88a; 88b; 88c; 88d; 88e is configured in at least one of the 40 following shapes:

P8077901NL4 -39- e said outer surface has a corrugated cross section along its entire length defining a plurality of first cable channels 96; 96a; 96b each one arranged to accommodate at least a portion of one cable 90, and e said inner surface has a corrugated cross section along its entire length defining a plurality of second cable channels 97 each one arranged to accommodate at least a portion of one cable 90, b. manufacturing at least one slotted structure 72; 74; 106; 158 in said tube element 88; 88a; 88b; 88c; 88d; 88e to provide said tube element 88; 88a; 88b; 88c; 88d; 88e with at least one deflectable section.

[00276] When the tube element is made from a metal, the at least one slotted structure is advantageously made by laser cutting. Such laser cutting may be performed by directing a laser beam perpendicular to said outer surface of said tube element. Either the tube element may be rotated during the laser cutting or the laser may be rotated about the central axis of the tube element. Thus, due to the corrugated structure of the tube element, the laser beam has a changing direction over time and is off-axis during at least during part of the cutting time.

[00277]Briefly stated, a steerable instrument is manufactured from the flexible tube element having a proximal end and a distal end by providing at least one steering device 168 at said proximal end, providing one ore cables and connecting said one or more cables to said steering device 168 at the proximal end and to said deflectable section to allow deflection of said deflectable section by means of said steering device 168.

[00278] All above solution aim towards a design in which each component serves multiple purposes and is integrally manufactured from one piece of base material. So instead of separate parts for cable channels, hinges, flexible zones and layer attachment means one can have one part with all functionality and features. This will minimize cost of part manufacturing and assembly tremendously.

[00279] Because the intermediate tube elements described above have at least a portion of a guiding channel for cables and are provided with slotted structures to provide them with a desired flexibility and deflectability, friction on the cables will be reduced. This greatly facilitates controlling the operation of the deflectable tip at the distal end, but also of a tool at the tip if such a tool is operated by a cable extending from the proximal end. Controlling manipulation of objects, e.g. in a human body, like gripping, moving, cutting, and/or stitching a needle through tissue, is becoming easier.

[00280] The distal end may comprise more than one deflectable zone. The most distal deflectable zone would be an articulation zone whereas the most but one distal zone could be a triangulation zone. One or more of these deflectable zones at the distal end could be controlled by longitudinal elements in a tube element made by laser cutting in an originally cylindrical tube, as explained in detail in above mentioned patent applications WO 2009/112060 A1, WO 2009/127236 A1, WO 2017/213491 A1, and WO 2018/067004. Alternatively, one or more of those deflectable zones can be controlled by ball-shaped steering elements or by a robot.

40

P80779801NL1 -40-

[00281]An aspect of the invention explained here, relates to a slotted structures with a special design as will be explained in detail below. This slotted structure may be applied at any location where the instrument explained with reference to the above figures has a hinge.

[00282] Bendable zones in cylindrical elements may be implemented by means of hinges manufactured as a slotted structure in the cylindrical element. Such slots may be made by laser cutting or water cutting through the cylindrical element. There is a continuous desire to optimize such hinges as to flexibility (i.e., bendable capacity), resistance against elasticity in the longitudinal direction of the cylindrical element (longitudinal stiffness), and resistance against elasticity in the tangential direction of the cylindrical element (tangential stiffness). There is a special need for hinges that provides the cylindrical element with a bending capacity of more than 90° along an as short as possible longitudinal portion of the cylindrical element without the hinge getting outside its elastic range. More specific back ground as to hinges is as follows.

[00283] In steerable instruments as described in WO2009/112060 and WO02009/127236, the flexible sections in the inner and outer layers need some kind of hinges and / or elastic structures to provide for bendability of these sections. Preferably, bending of these sections requires minimal force and has minimal friction but the flexible sections should have sufficient longitudinal and torsion (rotational) strength to provide for robust handling and manipulation performance. Another requirement is that after manufacturing the required geometries and features in these layers, the processed tube should still be in one piece and straight for further handling, alignment and instrument assembly steps.

[00284] Hinges can be formed by small elements of material that can bend easily by elastic deformation and that keep the processed tube in one piece and straight as is shown in for example WO2009/112060, WO2009/127236 and WO2018/067004. Disadvantage of these types of hinges is that the bendability is limited because one wants to keep deformation of the hinge element elastically instead of plastically. Plastic deformations would result in a very short fatigue life of the hinges and structural integrity of the instrument can then only be maintained for a small number of deflections of the bendable zones. Another disadvantage is that elastically bending the material of the hinges requires a relatively high force which requires the use of strong pulling wires to prevent deflection losses due to elastic stretching of the pulling wires.

[00285] Hinges can also be formed by cutting real hinges in which a circularly shaped hinge element can rotate freely in a corresponding recess. To prevent that the tube after processing falls apart, the shape of this hinge has to be such that the circular element is enclosed more than 180 degrees by the corresponding recess, which provides for longitudinal integrity. But the hinges can still separate by sliding along the hinge axis itself (perpendicular to the longitudinal axis of the tube) and so the processed tube can still fall apart in separate parts. Also, after processing, a tube with these hinges will not stay straight after processing, is very floppy and will bend easily. This makes further handling, alignment and instrument assembly difficult. These hinges are, for example, explained in non-pre-published Dutch patent application NL2021823 figure 5A. To prevent floppiness of the tube and separation of parts along the hinge axis after processing, one could incorporate very small and

P80779801NL1 -41- easily bendable elastic bridges in these hinges as is explained in NL2021823 figures 16B and 18. One could also apply releasable attachments as explained in WO2016089202 in such a hinge to keep the tube in one piece and straight after processing. This combination of a ‘true’ hinge, combined with releasable attachments is shown in NL2021823 figure 18A. The main disadvantage of this ‘true’ hinge is that the deflection is strongly limited by the hinge geometry itself when one wants to keep the overall size of the hinge structure within acceptable limits as one can see in NL2021823 figure 10. Another disadvantage in a combination with elastically deformable elements is the increased bending force. Hinges as explained hereinafter avoid one or more of these disadvantages.

[00286] Figure 20a shows a cylindrical element 500 with a hinge 501 made as a slotted structure. The cylindrical element 500 comprises a portion 504 and a further portion 509 opposite to portion

504. Hinge 501 is located in between them.

[00287]Hinge 501 comprises a plurality of hinge portions 502(1), 502(2), ... 502(n), ..., 502(N) (N being an integer number being larger than 1). In the shown example, each hinge portion 502(n} has an identical shape but that is not necessarily so. Each shown hinge portion 502(n) is a rigid ring shaped portion of cylindrical element 500.

[00288] Portion 504 and hinge portion 502(1) are rotatable relative to one another by means of two rotatable sections 507(1) (one visible in figure 20a) located 1800 rotated relative to one another in the tangential direction of cylindrical element 500. To that effect, ring shaped portion 502(1) is provided with two extensions 506(1) (only one visible in figure 20a) arranged 1800 opposite to each other as seen in the tangential direction of the cylindrical element 500. Each extension 506(1) has a circular outer edge oriented towards portion 504. Portion 504 is provided with two notches 505(1) (only one visible in figure 20a) arranged 1800 opposite to each other as seen in the tangential direction of the cylindrical element 500. Each notch 505(1) has a circular inner edge of a same radius as the circular outer edge of extension 506(1). Each notch 505(1) accommodates one extension 506(1).

[00289] Preferably, extension 506(1) and notch 505(1) are made by cutting a circular shaped slot through cylindrical element 500, e.g. by laser cutting or water cutting. Any other cutting technique may be used instead. In an example, the cutting process is performed such that the slot is interrupted by small bridges 510(1) such that extension 506(1) and notch 505(1) are still attached to each other. These bridges operate as “fracture elements” as explained in detail in patent application WO 2016/089202 A1. They will break once a force above a certain threshold is applied to them. Here they are designed such that they will break once portion 504 and hinge portion 502(1) are rotated relative to one another about the two extensions 506(1) with at least such a threshold force, as shown with double arrow 503. The threshold force is selected such that the bridges 510(1) will break before either one of portion 504 or hinge portion 502(1) will deform beyond its maximum elasticity due the exerted rotation force. As will be explained hereinafter, they are only broken later during the manufacturing process.

P80779801NL1 -42-

[00290] Portion 504 is provided with an outer edge 514 facing an outer edge 512 of hinge portion 502(1). Outer edge 514 and outer edge 512 define an open space between them such that, once the bridges 510(1) are broken, portion 504 and hinge portion 502(1) can freely rotate relative to one another about extensions 506(1) until a predetermined bending angle which is reached when outer edges 514 and 512 touch one another.

[00291] Outer edges 514 and 512 result from cutting, e.g. laser cutting or water cutting a predetermined pattern through cylindrical element 500. All adjacent hinge portions 502(n), 502(n+1) have open spaces between them like the spaces as defined between portion 504 and hinge portion 502(1) resulting from cutting, e.g. laser cutting or water cutting. These spaces are alternately rotated 900 viewed in the tangential direction of cylindrical element 500.

[00292] Hinge portion 502(1) has a further outer edge 515 facing an outer edge 517 of hinge portion 502(2). Outer edge 515 is provided with two circular shaped notches 505(2) (one visible in figure 20a) arranged 1800 opposite to each other as seen in the tangential direction of the cylindrical element 500. Each circular shaped notch 505(2) accommodates a circular shaped extension 506(2) of hinge portion 502(2). Each combination of notch 505(2) and extension 506(2) is at a location rotated 900 relative to a combination of notch 505(1) and extension 506(1). Like combinations of notch 505(1) and extension 506(1), combinations of notch 505(2) and extension 506(2) are, in an example, made by cutting a circular shaped slot through cylindrical element 500, e.g. by laser cutting or water cutting. Any other cutting technique may be used instead. In an example, the cutting is performed such that the slot is interrupted by small bridges 510(2) similar to bridges 510(1) such that extension 506(2) and notch 505(2) are still attached to each other. These bridges also operate as “fracture elements” as explained above.

[00293] Because successive rotatable sections 507(n) and 507(n+1) are rotated about 900 relative to one another as viewed in the tangential direction of cylindrical element 500, hinge portion 502(n- 1) and hinge portion 502(n} can rotate relative to each other in a first direction perpendicular to a second direction of rotation of hinge portion 502(n) relative to hinge portion 502(n+1). As shown, the directions of rotation between successive hinge portions alternate between said first and second directions causing the hinge 501 to be flexible in all directions.

[00294] In an example, each notch 505(n) is still attached to extension 506(n) it accommodates by means of bridges similar or identical to bridges 510(1) once a slot is made between them. So, after the cylindrical element structure 500 of figure 20a is made, in such an example, all adjacent portions and hinge portions are still attached to each other and the structure will not fall apart in separate pieces. Therefore, once ready, the cylindrical element structure 500 of figure 20a can be inserted into cylindrical element structure 520 shown in figure 20b as an integral unit. This cylindrical element 520 can also be made as an integral element in which all different portions and hinge portions are still attached to each other before the total hinge structure is used in a bending action.

[00295] Figure 20b shows cylindrical element 520 in detail.

P80779801NL1 -43-

[00296] Figure 20b shows cylindrical element 520 with a hinge 521 made as a slotted structure. The cylindrical element 520 comprises a portion 524 and a further portion 529 opposite to portion 524. Hinge 521 is located in between them.

[00297] Hinge 521 comprises a plurality of hinge portions 522(1), 522(2), ... 522(n), ..., 522(N) (N being an integer number being larger than 1). In the shown example, each hinge portion 522(n) has an identical shape but that is not necessarily so. Each shown hinge portion 522(n) is a rigid ring shaped portion of cylindrical element 520.

[00298] Portion 524 and hinge portion 522(1) are arranged to be rotatable relative to one another by means of two rotatable sections 530(1) (only one visible in figure 20b) located 1800 rotated relative to each other as seen in the tangential direction of cylindrical element 521. One such rotatable section 530 is shown in detail in figure 20d, as indicated with dotted circle Vd in figure 20b. A line connecting both rotatable sections 530(1) intersects a central axis of hinge 821. So, portion 524 and hinge portion 522(1) are rotatable about this line.

[00299] As shown in figure 20d, rotatable section 530(1) comprises an extension 548(1) provided with a circular shaped outer edge. This circular shaped extension 548(1) is accommodated in a circular shaped notch 550(1) of hinge portion 522(1). The radius of circular shaped extension 548(1) and the radius of circular shaped notch 550(1) are the same. They have the same center of rotation. The circular shaped extension 548(1) and the circular shaped notch 550(1) are separated by a small slot made by a cutting operation, e.g. laser or water cutting or any other suitable cutting technique. During production of the slot, the slot is interrupted at predetermined locations such that extension 548(1) and notch 550(1) are still attached to each other by means of one or more small bridges 552(1). These bridges 552(1) operate as “fracture elements” as defined above. l.e., they will break once a force above a certain threshold is applied to them. Here they are designed such that they will break once portion 524 and hinge portion 522(1) are rotated relative to one another about the two extensions 548(1) with at least such a threshold force. The threshold force is selected such that the bridges 552(1) will break before either one of portion 524 or hinge portion 522(1) will deform beyond its maximum elasticity due the exerted rotation force. As will be explained hereinafter, they are only broken later during the manufacturing process.

[00300] Extension 548(1) is provided with a circular slot 542(1) about its center of rotation. The radius of slot 542(1) is smaller than the radius of circular shaped extension 548(1) itself. Inside slot 542(1) a circular shaped island or disc 556(1) remains. During manufacturing of slot 542(1), slot 542(1) is interrupted by small bridges 540(1) by means of which circular shaped island 556(1) is still attached to the rest of extension 548(1). These bridges 540(1) operate as “fracture elements” as defined above. l.e., they will break once a force above a certain threshold is applied to them. Here they are designed such that they will break once circular disc 556(1) and extension 548(1) are rotated relative to one another with at least such a threshold force. The threshold force is selected such that the bridges 540(1) will break before either one of extension 548(1) or circular disc 556(1) will deform beyond its maximum elasticity due the exerted rotation force. As will be explained hereinafter, they are only broken later during the manufacturing process.

P8077901NL4 -44-

[00301]Reference number 544(1) refers to an attachment structure in circular disc 556(1). The attachment structure 544(1) is arranged such that circular disc 558(1) can be attached to circular shaped extension 506(1) of cylindrical element 500 once cylindrical element 500 is inserted into cylindrical element 520. Such an attachment can be made by any suitable attachment technique including gluing, soldering, welding and laser welding. To assist laser welding, attachment structure 544(1) may be formed as a small slotted structure, e.g. in the form of a S made by laser cutting or water cutting.

[00302] Hinge portion 522(1) may be provided with one or more lips 554(1) (one shown in figures 20b and 20d). Such a lip 554(1) may be located adjacent to rotatable section 530(1) at, substantially, the same tangential location as circular disc 556(1). The lips 554(1) are used to attach hinge portion 522(1) of cylindrical tube 520 to hinge portion 502(1) of cylindrical element 500, e.g., by welding or laser welding once cylindrical element 500 is inserted into cylindrical element 520.

[00303] Referring again to figure 20b, hinge portion 522(1) and hinge portion 522(2) are arranged such that they can rotate relative to one another about two rotatable sections 530(2) (only one shown in figure 20b) located 1800 rotated relative to one another as viewed in the tangential direction of cylindrical element 520. The structure of rotatable sections 530(2) is, preferably, identical to rotatable section 530(1). So, rotatable section 530(2) has, preferably, the same elements as rotatable section 530(1) as shown in figure 20d, in which all indices (1) are replaced by (2). Rotatable sections 530(2) are located at locations 900 rotated relative to the locations of rotatable sections 530(1) as viewed in the tangential direction of cylindrical element 520.

[00304] Defined in more general terms, the rotation mechanism between two adjacent hinge portions 522(n) and 522(n+1) is as follows. Hinge portion 522(n) and hinge portion 522(n+1) are arranged such that they can rotate relative to one another about two rotatable sections 530(n+1) located 1800 rotated relative to one another as viewed in the tangential direction of cylindrical element 520. The structure of rotatable sections 530(n+1) is, preferably, identical to rotatable section 530(1). So, rotatable section 530(n+1) has the same elements as rotatable section 530(1}) as shown in figure 20d, in which all indices (1) are replaced by (n+1). Rotatable sections 530(n+1) are located at locations 900 rotated relative to the locations of rotatable sections 530(n) and 530(n+2) as viewed in the tangential direction of cylindrical element 520. Also rotatable sections 530(n) and 530(n+2) are, preferably, identical to rotatable section 530(1).

[00305] Portion 524 is provided with an outer edge 526 facing an outer edge 528 of hinge portion 522(1). Outer edge 526 and outer edge 528 define an open space between them such that, once the bridges 552(1) are broken, portion 524 and hinge portion 522(1) can freely rotate relative to one another about extensions 548(1) until a predetermined bending angle which is reached when outer edges 526 and 528 touch one another.

[00306] Outer edges 526 and 528 result from cutting, e.g. laser cutting or water cutting a predetermined pattern through cylindrical element 520. All adjacent hinge portions 522(n), 522(n+1) have open spaces between them like the spaces as defined between portion 524 and hinge portion

P8077901NL4 -45- 522(1) resulting from cutting, e.g. laser cutting or water cutting. These spaces are alternately rotated 900 viewed in the tangential direction of cylindrical element 520.

[00307] Because successive rotatable sections 530(n) and 530(n+1) are rotated about 900 relative to one another as viewed in the tangential direction of cylindrical element 520, hinge portion 522(n- 1) and hinge portion 522(n} rotate relative to each other in a first direction perpendicular to a second direction of rotation of hinge portion 522(n) relative to hinge portion 522(n+2). As shown, the directions of rotation between successive hinge portions alternate between said first and second directions causing the hinge 521 to be flexible in all directions.

[00308] In an example, each notch 550(n) is still attached to extension 548(n) by means of bridges 552(n) once a slot is made between them. So, after the cylindrical element structure 520 of figure 20b is made, in such an example, all different portions are still attached to each other and the structure will not fall apart in separate pieces. Moreover, after making cylindrical element 520 also all circular discs 556(n) are still attached to the surrounding circular extension 548(n) by means of bridges 540(n). Therefore, once ready, the cylindrical element structure 520 of figure 20b is still an integral unit once cylindrical element 500 is ready to be inserted into cylindrical element structure

520. Moreover, before being inserted into one another both cylindrical elements 500, 520 still have a straight structure because of all bridges 510(n}, 552(n) making the action of inserting the two cylindrical elements 500, 520 into one another easy.

[00309] Bridges 552(1) and 540(1) are designed as “fracture elements”. l.e., they will break once a predetermined force is applied to them which is lower than a force necessary to deform the surrounding material beyond its maximum elasticity.

[00310] Figure 20c shows the resulting hinge structure once cylindrical elements 500, 520 are inserted into each other. As shown, in the assembled state, cylindrical elements 500, 520 are both longitudinally and tangentially aligned with one another such that each rotatable section 530(n) of cylindrical element 520 is aligned with one rotatable section 507(n) of cylindrical element 500. In order to finalize the assembling, once cylindrical element 500 is inserted into cylindrical element 520, each attachment structure 544(n) is attached to one circular extension 506(n), e.g., by gluing, soldering, welding or laser welding. Optionally, also one or more hinge portions 522(n) are attached to hinge portions 502(n), e.g., by gluing, soldering, welding, or laser welding lips 554(n) to hinge portion 502(n). This latter action provides more rigidity to the total hinge structure.

[00311] Portion 529 can be attached to portion 509 in a similar way, e.g., by gluing, soldering, welding, or laser welding lips 534 to portion 509, or in any other suitable way. Similarly, portions 524 and 524 can be attached to one another.

[00312] Once cylindrical elements 500 and 520 are attached to one another in this way, a user can exert a rotation force in directions as indicated with double arrows 503 in figure 20a. By having the rotation force exceeding a certain threshold value all “fracture elements 510(n}, 540(n) and 552(n) will break. Consequently, portions 504/524 can freely rotate relative to adjacent hinge portions 502(1)/522(1) about pin 556(1), and hinge portions 502(n)/522(n) can freely rotate relative to

P80779801NL1 -46- adjacent hinge portions 502(n+1)/522(n+1) about pin 556(n+1). Equally, portions 509/529 can freely rotate relative to hinge portions 502(N)/522(N).

[00313] Moreover, each circular shaped island 556(n) is firmly attached to a circular extension 506(n) in cylindrical element 500 and can freely rotate together with it within extension 548(n) in cylindrical element 520. By this structure, circular shaped island 556(n} acts as a pin, or spindle, having two functions. First, it acts as an pin of rotation about which extension 548(n) rotates.

Second, because the slot between pin 556(n) and extension 548(n) can be very narrow, pin 556(n) acts to keep hinge portions 502(n)/522(n) and adjacent hinge portions 502(n+1)/522(n+1) in a well defined position relative to one another with little play between them. The same is true for the position of portions 504/524 relative to hinge portions 502(1)/522(1) and hinge portions 502(N)/522(N) relative to portions 509/529.

[00314] Figure 21 shows a schematic cross section through extension 506(n) of cylindrical element 500, and how such an extension 506(n) is attached to pin 556(n) which is rotatably arranged in a hole in extension 548(n) in cylindrical element 520 as defined by slot 542(n). Pin 556(n) is attached to extension 506(n), e.g., by (laser) welding attachment structure 544(n) to extension 506(n). Since the structure is rotation symmetric, cylindrical element 500 has two such pins 556(n) at opposite sides of its axis of symmetry (so at locations rotated by 1800 viewed in the tangential direction) both accommodated in a hole defined by slot 542(n). This provides for a solid structure where adjacent portions of the hinge structure can freely rotate relative to one another while being connected to each other. Note also that adjacent hinge portions 502(n)/522(n) and 502(n+1)/522(n+1) are not attached to one another anymore by any portion of material of either cylindrical element 500 or cylindrical element 520. So, there is no elastic deformation of any material which would develop a counter rotation force during rotation.

[00315] Figure 22 shows that pin 556(n} can be further attached to an extension 848(n) of a cylindrical element 820 surrounding cylindrical element 520 as shown in figures 23a and 23b. this can be done by gluing, soldering, welding, or laser welding extension 848(n) to pin 556(n) by an attachment structure 844(n).

[00316] Figure 23a shows cylindrical element 820 in more detail.

[00317] Figure 23a shows cylindrical element 820 with a hinge 821 made as a slotted structure. The cylindrical element 820 comprises a portion 824 and a further portion 829 opposite to portion 824.

Hinge 821 is located in between them.

[00318] Hinge 821 comprises a plurality of hinge portions 822(1), 822(2), ... 822(n), ..., 822(N) (N being an integer number being larger than 1). In the shown example, each hinge portion 822(n) has an identical shape but that is not necessarily so. Each shown hinge portion 822(n) is a rigid ring shaped portion of cylindrical element 820.

[00319] Portion 824 and hinge portion 822(1) are arranged to be rotatable relative to one another by means of two rotatable sections 830(1) {only one visible in figure 23b) located 1800 rotated relative to each other as seen in the tangential direction of cylindrical element 821. One such

P80779801NL1 -47- rotatable section 830(1) is shown in detail in figure 23c, as indicated with dotted circle Vd in figure 23b. A line connecting both rotatable sections 830(1) intersects a central axis of hinge 821. So, portion 824 and hinge portion 822(1) are rotatable about this line.

[00320] As shown in figure 23c, rotatable section 830(1) comprises an extension 848(1) provided with a circular shaped outer edge. This circular shaped extension 848(1) is accommodated in a circular shaped notch 850(1) of hinge portion 822(1). The radius of circular shaped extension 848(1) and the radius of circular shaped notch 850(1) are the same. They have the same center of rotation. The circular shaped extension 848(1) and the circular shaped notch 850(1) are separated by a small slot made by a cutting operation, e.g. laser or water cutting or any other suitable cutting technique. During production of the slot, the slot is interrupted at predetermined locations such that extension 848(1) and notch 850(1) are still attached to each other by means of one or more small bridges 852(1). These bridges 852(1) operate as “fracture elements” as defined above. l.e., they will break once a force above a certain threshold is applied to them. Here they are designed such that they will break once portion 824 and hinge portion 822(1) are rotated relative to one another about the two extensions 848(1) with at least such a threshold force. The threshold force is selected such that the bridges 852(1) will break before either one of portion 824 or hinge portion 822(1) will deform beyond its maximum elasticity due the exerted rotation force. As will be explained hereinafter, they are only broken later during the manufacturing process.

[00321] Reference number 844(1) refers to an attachment structure in circular extension 848(1). The attachment structure 844(1) is arranged such that circular extension 848(1) can be attached to pin 556 (1) of cylindrical element 520 once cylindrical element 520 is inserted into cylindrical element 820. Such an attachment can be made by any suitable attachment technique including gluing, soldering, welding and laser welding. To assist laser welding, attachment structure 8441) may be formed as a small slotted structure, e.g. in the form of a S made by laser cutting or water cutting.

[00322] Hinge portion 822(1) may be provided with one or more lips 854(1) (one shown in figures 23b and 23c¢). Such a lip 854(1) may be located adjacent to lip 554(1) of cylindrical element 520 (cf. figure 20d). The lips 854(1) are used to attach hinge portion 822(1) of cylindrical tube 820 to hinge portion 522(1) of cylindrical element 520, e.g., by welding or laser welding once cylindrical element 520 is inserted into cylindrical element 820. By doing so, hinge portions 502(1), 522(1), and 822(1) will be firmly attached to one another.

[00323] Note that extension 506(1) of cylindrical element 500 is oriented in the same longitudinal direction as extension 848(1) of cylindrical element 820 whereas both these extensions are oriented in opposite longitudinal direction as extension 548(1) of cylindrical element 520. Thus, extension 548(1) can rotate between extensions 506(1) and 848(1) about pin 556(1) which pin 556(1) is attached at one end to extension 506(1) and at its opposing end to extension 848(1).

[00324] Referring again to figure 23a, hinge portion 822(1) and hinge portion 822(2) are arranged such that they can rotate relative to one another about two rotatable sections 830(2) (only one

P80779801NL1 -48- shown in figure 23a) located 1800 rotated relative to one another as viewed in the tangential direction of cylindrical element 820. The structure of rotatable sections 830(2) is, preferably, identical to rotatable section 830(1). So, rotatable section 830(2) has, preferably, the same elements as rotatable section 830(1) as shown in figure 23c, in which all indices (1) are replaced by (2). Rotatable sections 830(2) are located at locations 900 rotated relative to the locations of rotatable sections 830(1) as viewed in the tangential direction of cylindrical element 820.

[00325] Defined in more general terms, the rotation mechanism between two adjacent hinge portions 822(n) and 822(n+1) is as follows. Hinge portion 822(n) and hinge portion 822(n+1) are arranged such that they can rotate relative to one another about two rotatable sections 830(n+1) located 180° rotated relative to one another as viewed in the tangential direction of cylindrical element 820. The structure of rotatable sections 830(n+1) is, preferably, identical to rotatable section 830(1). So, rotatable section 83CG(n+1) has the same elements as rotatable section 830(1} as shown in figure 23c, in which all indices (1) are replaced by (n+1). Rotatable sections 830(n+1) are located at locations 90° rotated relative to the locations of rotatable sections 830{n) and 830(n+2) as viewed in the tangential direction of cylindrical element 820. Also rotatable sections 830(n) and 830(n+2) are, preferably, identical to rotatable section 830(1).

[00326] Portion 824 is provided with an outer edge 826 facing an outer edge 828 of hinge portion 822(1). Outer edge 826 and outer edge 828 define an open space between them such that, once the bridges 852(1) are broken, portion 824 and hinge portion 822(1) can freely rotate relative to one another about extensions 848(1) until a predetermined bending angle which is reached when outer edges 826 and 828 touch one another.

[00327] Outer edges 826 and 828 result from cutting, e.g. laser cutting or water cutting a predetermined pattern through cylindrical element 820. All adjacent hinge portions 822(n), 822(n+1) have open spaces between them like the spaces as defined between portion 824 and hinge portion 822(1) resulting from cutting, e.g. laser cutting or water cutting. These spaces are alternately rotated 900 viewed in the tangential direction of cylindrical element 820.

[00328] Because successive rotatable sections 830(n) and 830(n+1) are rotated about 900 relative to one another as viewed in the tangential direction of cylindrical element 820, hinge portion 822(n- 1) and hinge portion 822(n} rotate relative to each other in a first direction perpendicular to a second direction of rotation of hinge portion 822(n) relative to hinge portion 822(n+2). As shown, the directions of rotation between successive hinge portions alternate between said first and second directions causing the hinge 821 to be flexible in all directions.

[00329] In an example, each notch 850(n) is still attached to extension 848(n) by means of bridges 852(n) once a slot is made between them. So, after the cylindrical element structure 820 of figure 23b is made, in such an example, all different portions are still attached to each other and the structure will not fall apart in separate pieces. Therefore, once ready, the cylindrical element structure 820 of figure 23a is still an integral unit once cylindrical element 520 is ready to be inserted into cylindrical element structure 820. Moreover, before being inserted into one another both

P80779801NL1 -49- cylindrical elements 520, 820 still have a straight structure because of all bridges 552(n), 852(n) making the action of inserting the two cylindrical elements 520, 820 into one another easy.

[00330] Bridges 852(1) and 840(1) are designed as “fracture elements”. l.e., they will break once a predetermined force is applied to them which is lower than a force necessary to deform the surrounding material beyond its maximum elasticity.

[00331] Figure 23b shows the resulting hinge structure once cylindrical elements 500, 520, and 820 are inserted into each other. As shown, in the assembled state, cylindrical elements 500, 520, 820 are longitudinally and tangentially aligned with one another such that each rotatable section 530(n) of cylindrical element 520 is aligned with both one rotatable section 507(n) of cylindrical element 500 as well as with one rotatable section 830(n) of cylindrical element 820. In order to finalize the assembling, once cylindrical element 500 is inserted into cylindrical element 520, each pin 556(n), e.g., by attachment structure 544(n), is attached to one circular extension 506(n), e.qg., by gluing, soldering, welding or laser welding. Once, after that, cylindrical element 520, together with cylindrical element 500, is inserted into cylindrical element 820, and each extension 848(n), e.g., by attachment structure 844(n), is attached to pin 556(n), e.g., by gluing, soldering, welding or laser welding.

[00332] Optionally, also one or more hinge portions 822(n) are attached to hinge portions 522(n), e.g., by gluing, soldering, welding, and/or laser welding lips 854(n) to lips 554(n). This latter action provides more rigidity to the total hinge structure.

[00333] Portion 829 can be attached to portion 809 in a similar way, e.qg., by gluing, soldering, welding, or laser welding lips 834 to portion 809, or in any other suitable way. Similarly, portions 824 and 824 can be attached to one another.

[00334] Once cylindrical elements 500, 520 and 820 are attached to one another in this way, a user can exert a rotation force in directions as indicated with double arrows 803 in figure 23a. By having the rotation force exceeding a certain threshold value all “fracture elements” 510(n), 540(n), 552(n) and 852(n) will break. Consequently, portions 504/524/824 can freely rotate relative to adjacent hinge portions 502(1)/522(1)/822(1) about pins 556(1), and hinge portions 502(n)/522(n)/822(n) can freely rotate relative to adjacent hinge portions 502(n+1)/522(n+1)/822(n+1) about pins 556(n+1). Equally, portions 509/529/829 can freely rotate relative to hinge portions 502(N)/522(N)/822(N).

[00335] Moreover, each circular shaped island 856(n) is firmly attached to a circular extension 806(n) in cylindrical element 800 and can freely rotate together with it within extension 848(n) in cylindrical element 820. By this structure, circular shaped island 856(n) acts as a pin, or spindle, having two functions. First, it acts as an pin of rotation about which extension 848(n) rotates. Second, because the slot between pin 856(n) and extension 848(n) can be very narrow, pin 856(n) acts to keep hinge portions 802(n)/522(n) and adjacent hinge portions 802(n+1)/522(n+1) in a well defined position relative to one another with little play between them. The same is true for the position of portions 804/524 relative to hinge portions 802(1)/522(1) and hinge portions 802(N)/522(N) relative to portions 809/529.

P8077901NL4 -50-

[00336]Figures 24a, 24b and 24c show an embodiment of the hinge structure of the present invention as applied in a steerable instrument having steering cables for the instrument. Such a steerable instrument may be based on any one of the instruments shown with reference to figures 1-19c. Below, the application of the hinge structure of the present invention will be explained with reference to a steerable instrument with steering cables in one cylindrical element. However, the invention can be applied in any steerable instrument with one or more cylindrical elements with steering cables arranged to steer bending of one or more bendable sections in the steerable instrument.

[00337]Figure 24a show an inner cylindrical element, whereas figure 24b shows an intermediate cylindrical element with such steering cables having the inner cylindrical element inserted into it. Figure 24c shows an outer cylindrical element into which a set of the inner cylindrical element and the intermediate cylindrical element are inserted.

[00338] Figure 24a shows an example of a tip of an inner cylindrical element 920 which may be at the distal end or proximal end of the instrument. For the present explanation it will be assumed to be located at the distal end but an equal arrangement may be located at the proximal end. Alternatively, the steering cables may be steered by means of a ball shaped member or a motor of a robotic steering mechanism. As explained above, the tip of the instrument is steerable. The inner cylindrical element may be entirely flexible and may be made of any suitable material including any type of plastic or metal that can be used in a medical environment. The structure of figure 24a is but one example of a possible embodiment in which flexibility is provided by means of a slotted hinge structure 921.

[00339] The slotted hinge structure 921 is arranged proximally from a ring shaped end portion 924 of cylindrical element 920. Slotted hinge structure 921 comprises a plurality of hinge portions 922(1), 922(2), ..., 922(n), , 922(N). end portion 924 is rotatably arranged relative to hinge portion 922(1) and hinge portion 922(N) is rotatably arranged relative to a cylindrical element portion 929 arranged proximally from hinge structure 921.

[00340]End portion 924 can rotate relative to hinge portion 922(1) about two rotation sections 930(1) located 1800 rotated relative to one another as viewed in the tangential direction of cylindrical element 920. |.e., a line connecting the two rotation sections 930(1) intersects an axis of symmetry of cylindrical element 920. When end portion 924 rotates relative to hinge portion 922(1) the rotation is about this line.

[00341] Between each adjacent two hinge portions 922(n) and 922(n+1) two rotation sections 930(n+1) are present such that they can rotate relative to one another about a line connecting these two rotation sections 930(n+1). In an embodiment, all rotation sections 930(n) are identical but that is not strictly necessary.

[00342] An example of such a rotation section 930(n) is provided with reference to rotation section 930(2). Rotation section 930(2) is located between hinge portions 822(1) and 922(2). At a location 1800 rotated relative to the location of rotation section 930(2) there is second rotation section

P8077901NL4 -51- 930(2). Rotation section 930(2) comprises a circular extension 948(2) of hinge portion 922(1).

Extension 948(2) is accommodated in a circular notch 950(2) in hinge portion 922(2). Extension 948(2) and notch 950(2) are separated by a slot cut through cylindrical element 920. During cutting, e.g. by laser cutting or water cutting, and producing the slot, extension 948(2) and notch 950(2) remain attached to each other by means of small bridges 952(2) which act as “fracture elements” as explained above. l.e., they are designed such that they will break when hinge portions 922(1) and 922(2) are rotated relative to one another with a predetermined force above a certain threshold force which is below a force required to deform the surrounding material of hinge portions 922(1) and 922(2) beyond their maximum elasticity.

[00343] A center point of extension 948(2) defines a point of rotation about which hinge portions 922(1) and 922(2) will be rotatable once the bridges 952(2) are broken.

[00344] Rotation section 930(2) also comprises two lip elements 960(2), 862(2) extending from hinge portion 922(2) towards hinge portion 922(1). Both lip elements 960(2) and 962(2) have a circular shape and are located at a radial distance from the point of rotation which is larger than the radius of circular extension 948(2). Lip element 960(2) can be moved in a circular direction in a circular shaped slot 964(2) arranged in hinge portion 922(1). Lip element 862(2) can be moved in a circular direction in a circular shaped slot 966(2) arranged in hinge portion 922(1).

[00345] The lip elements 960(2), 962(2), as well as the circular slots 984(2}, 966(2) can be formed by cutting, e.g. by laser cutting or water cutting, a predetermined pattern through cylindrical element 920, as will be evident to a person skilled in the art. During that cutting process, lip elements 960(2) and 962(2) may remain attached to surrounding material from hinge portion 922(1) by means of small bridges acting as “fracture elements” as explained above.

[00346] Lip elements 960(2) and 962(2) accommodate a portion of hinge portion 922(1) including circular extension 948(2) such that hinge portions 822(1) and 922(2) cannot easily move relative to one another in the longitudinal direction of the cylindrical element 920.

[00347] Hinge portion 922(1) has an edge 968 facing an edge 970 of hinge portion 922(2) which are shaped such that they define a predetermined open space between hinge portions 922(1) and 922(2). This open space as well as the length of the slots 964(2), 966(2) determine an angel about which hinge portions 922(1) and 922(2) can rotate relative to one another.

[00348] Note that when one rotates hinge portions 922(1), 922(2) relative to one another with a predetermined force above a predetermined threshold value in a direction indicated with double arrow 903, fracture elements 952(2) (as well as possible fracture elements attaching lip elements 960(2), 962(2) to adjacent material of hinge portion 922(1)) will break, such that hinge portions 922(1) and 922(2) are no longer attached to each other and can freely rotate. This, however, is preferably not done prior to inserting inner cylindrical element 920 into intermediate cylindrical element 1020 shown in figure 24b.

P8077901NL4 -52-

[00349] Again, consecutive rotation sections 930(n) and 930{n+1} are 900 rotated in the tangential direction of cylindrical element 920 to provide hinge structure 921 with complete flexibility in all directions.

[00350] Figure 24b shows an example of intermediate cylindrical element 1000. Intermediate cylindrical element 1000 comprises a ring shaped distal end portion 1002 which is attached to a plurality of steering cables 1004. When one desires bendability in one (and the opposite) direction two such steering cables 1004 are sufficient. However, if one wishes bendability in all directions at least three steering cables 1004 should be applied. The steering cables 1004 are, in an example, located at tangentially equidistant locations. In the present example, 8 such steering cables 1004 are applied.

[00351] As shown in figure 24b, two adjacent steering cables 1004 are protected from tangential movements relative to one another by tangential spacers. Two different sets of tangential spacers are shown. A first set comprises spacers 1028 formed as a longitudinal strip with spacer elements at both sides tangentially extending to such an extent that they touch adjacent steering cables 1004. These spacer elements may have any desired form, i.e, flexible plate like elements, M-shaped elements, S-shaped elements, pin-shaped elements, or any other suitable form known to persons skilled in the art. Spacers 1028 can, alternatively also be formed as flexible plate like elements, M- shaped elements, S-shaped elements, pin-shaped elements, or any other suitable form known to persons skilled in the art, which are directly attached to either one of two adjacent steering cables 1004 and extend to the other one of the two adjacent steering strips 1004, as is known from the prior art.

[00352] A second set of tangential spacers comprises a plurality of spacer elements 1005 consecutively arranged in the longitudinal direction between two adjacent steering cables 1004. The first set of spacers 1028 and the second set of spacers 1005 alternate in the tangential direction of cylindrical element 1000.

[00353] Each spacer element 1005 comprises a plate 1006 separated from adjacent steering strips 1004 by a slot resulting from cutting, e.g. laser cutting or water cutting, through cylindrical element

1000. During cutting, plate 1006 preferably remains attached to one or both adjacent steering strips 1004 by a “fracture element” 1012. Fracture element 1012 is designed such that when a relative longitudinal force is applied between steering strip 1004 and plate 1006 to which fracture element 1012 is attached, fracture element 1012 will break once that force exceeds a certain threshold force. The threshold force should be selected such that the resulting forces in steering strip 1004 and plate 1006 remain below their maximum elasticity.

[00354] In the embodiment shown, plate 1006 is attached to a further plate 1014 which is separated from adjacent steering cables 1004 by a slot resulting from cutting, e.g. laser cutting or water cutting, a predetermined pattern through cylindrical element 1000. During cutting, plate 1014 preferably remains attached to one or both adjacent steering strips 1004 by a “fracture element” 1016. Fracture element 1016 is designed such that when a relative longitudinal force is applied between steering

P80779801NL1 -53- strip 1004 and plate 1014 to which fracture element 1016 is attached, fracture element 1016 will break once that force exceeds a certain threshold force. The threshold force should be selected such that the resulting forces in steering strip 1004 and plate 1014 remain below their maximum elasticity.

[00355] In an example, plate 1006 is attached to plate 1014 by means of a flexible attachment strip 1018 such that they are located at a predetermined longitudinal distance from each other. Attachment strip 1018 can, to that end, extend into plate 1014 (and/or into plate 1008), by having a slot at both sides as shown in figure 24b.

[00356] Plate 1014 has an edge 1020 facing towards the distal end and plate 1006 has an edge 1022 facing towards the proximal end. Consecutive spacer elements 1005 are longitudinally located at predetermined distances from one another as determined by a certain required flexibility of the instrument.

[00357] Once cylindrical elements 920 and 1000 are manufactured, both of them are integral cylindrical elements of which all different components are still attached to one another by means of fracture elements, as explained above. They are still straight and cylindrical element 820 can be inserted into cylindrical element 1000 easily. They are both longitudinally and tangentially aligned when inserted into each other. Then, in an embodiment, ends 924 and 1002 are attached to one another, e.qg., by gluing, soldering, welding, laser welding, etc.

[00358] Once inserted into each other, a set of cylindrical elements 920, 1002 is inserted into a cylindrical element that may have an identical shape as cylindrical element 520 as explained with reference to figures 20b and 20d. Figure 24c shows a (e.g., distal) end structure of an instrument in which this has been done. The set of cylindrical elements 920, 1002 is both longitudinally and tangentially aligned with cylindrical element 520. The alignment is such that each pin 556(n) located inside hinge portion 522(n-1) is radially aligned with and attached to a portion 1008 of plate 1006. That may be done by means of attachment structure 544(n) if present. Attachment can be done by gluing, welding, laser welding etc. Moreover, a portion of hinge portion 522(n) located at a longitudinally shifted position from pin 556(n} is attached to plate 1006 at a portion 1010 located at the same longitudinally shifted position from portion 1008. This portion of hinge portion 522(n) may be lip 554(n). In this way, each pin 556(n) located inside hinge portion 522(n-1) is firmly attached to hinge portion 522(n) by one single plate 1006 which is located itself in intermediate cylindrical element 1000. Moreover, plates 1006 also function as tangential spacers between adjacent steering cables in intermediate cylindrical element 1000.

[00359] Preferably, end portion 524 is attached to end portion 1002 once longitudinal and tangential alignment have been done.

[00360] Once all three cylindrical elements 920, 1000, 520 are inserted into each other, are longitudinally and tangentially aligned as desired, and attached to one another as explained above, a user may bend the instrument by exerting rotation forces 903 (cf. figure 24a) in all directions with such a force that all fracture elements keeping distinct components still attached to each other will

P80779801NL1 -54- break and the surrounding material is not exposed to forces beyond their maximum elasticity. All rotation sections in inner cylindrical element 920 and outer cylindrical element 520 will then be able to rotate freely. The only counter force against any bending is then developed in intermediate cylindrical element 1000 because, then, several components will bend elastically.

[00361] Of course, a further outer cylindrical element may be applied in the instrument of figures 24a, 24b, 24c, like cylindrical element 820 (figure 23a) to provide the total structure with more rigidity.

[00362] While the embodiment of figures 24a, 24b, and 24c show plates 1006 inside rotation sections 530(n), the cylindrical elements 1000 and 520 may be designed such that cylindrical element 520 is inserted into cylindrical element 1000 and plates 1006 are located outside rotation section 530(n).

[00363] The invention is not limited to the embodiments discussed so far. In the above explained embodiments, adjacent hinge portions 522(n), 522(n+1) of a cylindrical hinge 521 can rotate relative to one another because one of them is provided with two holes located opposite to one another viewed in the tangential direction. Each hole accommodates a pin 556(n) which is attached to an element 506(n), 1006 inside said cylindrical hinge 521 and/or to an element 848(n) outside said cylindrical element 521. That element 506(n), 1006 or 848(n) is also attached to a portion of the other hinge portion. Thus, the pin remains inside its corresponding hole and adjacent hinge portions remain at a well defined distance from each other. They can freely rotate relative to one another about the pins 556(n).

[00364] However, the pins themself need not be the centers of rotation as will be explained with reference to figure 25.

[00365] Figure 25 shows an alternative to outer cylindrical element 520. Figure 25 shows cylindrical element 1000 inserted into a cylindrical element 1100. Inside cylindrical element 1000 there may be any other suitable flexible cylindrical element as explained above with reference to cylindrical element 920. Also, again, there may be more cylindrical elements with steering cables to control bending of deflectable sections of the instrument.

[00366] Cylindrical element 1100 has an end portion 1124 which may be located at the distal end of the instrument. However, it may alternatively be a proximal end. Adjacent to end portion 1124, cylindrical element 1100 comprises a plurality of hinge portions 1122(1), 11222), ..., 1122(n), ..., 1122(N) of a (cylindrical) hinge 1121. End portion 1124 is rotatable relative to hinge portion 1122(1), like an end portion 1129 is rotatable relative to hinge portion 1122(N).

[00367] Each hinge portion 1122(n-1) is rotatable relative to an adjacent hinge portion 1122(n) by means of two rotatable sections 1130(n). End portion 1124 is rotatable relative to adjacent hinge portion 1122(1) by means of two rotatable sections 1130(1). Hinge portion 1122(N} is rotatable relative to end portion 1129 by means of two rotatable sections 1130(N+1). Each two rotation sections 1130(n) are located 1800 rotated relative to one another viewed in the tangential direction.

P80779801NL1 -55.

[00368] Rotation section 1130(1) is shown in more detail. However, all other rotation sections 1130(n) are, preferably, formed in the same way.

[00369] End portion 1124 has an outer edge 1126 facing towards outer edge 1128 of hinge portion 1122(1). Outer edges 1126 and 1128 are designed such that they define an open space between end portion 1124 and hinge portion 1122(1}. Edges 1126 and 1128 only touch one another at two predetermined locations 1160(1). During manufacturing these open spaces can be formed by cutting, e.g. laser cutting or water cutting, a predetermined pattern through cylindrical element 1100. At locations 1160(1) fracture elements may be applied to keep end portion 1124 and hinge portion 1122(1) still attached to each other as long as cylindrical element 1000 is not yet inserted into cylindrical element 1100. Locations 1160(1) will become centers of rotation.

[00370] Hinge portion 1122(1) is provided with a pin 1156(1) that can be moved inside a slot 1158(1) in hinge portion 1122(1). Slot 1158(1) is made by cutting, e.g., laser cutting or water cutting, through hinge portion 1122(1) while at the same time forming pin 1156(1). Pin 1156(1) is, thus, a disc resulting from cutting in hinge portion 11221). Slot 1158(1) has a circular shape positioned at an arc of a circle having a center co-located with the center of rotation 1160(1).

[00371] Once cylindrical element 1100 is ready, cylindrical element 1000 is inserted into cylindrical element 1100 and properly aligned both longitudinally and tangentially. Note that, in this embodiment, cylindrical element 1000 comprises spacer elements 1005 below all rotation sections 1130(n), unlike in figure 24b which shows a slightly different spacer structure below rotation center 1130(1). In the embodiment of figure 25, plate 1014 of spacer element 1005 below rotation section 1130(1) may be part of end portion 1002. Center of rotation 1160(1) is aligned such that it is radially aligned with a flexible portion of attachment strip 1018 between plate 1014 and plate 1008. Pin 1156(1) is attached to plate 1008, e.g., by gluing, welding, laser welding, or the like. Moreover, a portion of end portion 1124 adjacent to rotation center 1160(1) is attached to plate 1014, e.g., by gluing, welding, laser welding, or the like. This portion of end portion 1124 may be a lip 1130(1) cut in end portion 1124. In this way, pin 1156(1) is attached to end portion 1124 and yet properly held in place in slot 1158(1). Attachment strip 1018 prevents longitudinal displacement between end portion 1124 and hinge portion 1122(1). Because rotation center 1160(1) is located above a flexible portion of attachment strip 1018 as viewed in the radial direction, end portion 1124 and hinge portion 1122(1) can rotate relative to one another about rotation centers 1160(1).

[00372] End portion 1124 is, preferably, attached to end portion 1002, e.g., by welding, gluing, or laser welding, or the like.

[00373] Two rotation sections 1130(n) between adjacent hinge portions 1122(n-1) and 1122(n), preferably have the same design as rotation section 1130(1). Center of rotation 1160(n) is aligned such that it is radially aligned with a flexible portion of attachment strip 1018 between plate 1014 and plate 1006. Pin 1156(n) is attached to plate 1006, e.g., by gluing, welding, laser welding, or the like. Moreover, a portion of hinge portion 1122(n-1) adjacent to rotation center 1160(n) is attached to plate 1014, e.g., by gluing, welding, laser welding, or the like. This portion of hinge portion 1122(n-

P8077901NL4 -56- 1) may be a lip cut in hinge portion 1122(n-1). In this way, pin 1156(n) is attached to hinge portion 1122(n-1) and yet properly held in place in slot 1158{n). Attachment strip 1018 prevents longitudinal displacement between hinge portion 1122(n-1) and hinge portion 1122(n). Because rotation center 1160(n) is located above a flexible portion of attachment strip 1018 as viewed in the radial direction, hinge portion 1122(n-1) and hinge portion 1122(n) can rotate relative to one another about rotation centers 1160(n).

[00374] Again, consecutive centers of rotation 1130(n-1) and 1130(n} are, preferably, located at positions rotated 900 relative to one another viewed in the tangential direction. If so, the total structure can be bent in any desired direction.

[00375] Note that when a user exerts a rotation force for the first time he will break the above mentioned fracture elements between edges 1126, 1128 at the rotation centers 1160(1) and between pins 1156(1) and the surrounding material of hinge portion 1122(1). Note also that pins 1156(1) are shown in figure 25 to have a shape of an arc of a circle, the same as slot 1158(1), however, with a smaller length. However, pins 1156(1) may have any other suitable shape, like a round shape. The same applies to all other fracture elements, and pins 1156(n), respectively. Every pin 1156(n} may be provided with a special attachment structure like a slotted structure 1144(n) supporting attachment by laser welding or the like.

[00376] Mutual clearances between adjacent cylindrical elements is so small that they can easily move relative to one another in the longitudinal direction as long as they are not attached to one another but that mutual radial play is kept at a minimum. The mutual clearances may be in a range of 0.02 to 0.1 mm. The thickness of the cylindrical elements may be in a range of 0.1-2.0 mm, preferably 0.1-1.0 mm, more preferably 0.1-0.5 mm, and most preferably 0.2-0.4 mm. The diameters of the cylindrical elements may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm.

[00377] Apart from steering cables 1004, all cylindrical elements of figures 20a-25 are, preferably, manufactured from a single cylindrical tube of any suitable material like stainless steel, cobalt- chromium, shape memory alloy such as Nitinol®, plastic, polymer, composites or other cuttable material. Alternatively, the cylindrical elements can be made by a 3D printing process. The thickness of that tube depends on its application. For medical applications the thickness may be in a range of 0.1-2.0 mm, preferably 0.1-1.0 mm, more preferably 0.1-0.5 mm, and most preferably

0.2-0.4 mm. The diameter of the inner cylindrical element depends on its application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably

0.5-6 mm.

[00378] The slots and openings in all cylindrical elements can be made by laser or water cutting.

The smaller slots which are made to just separate adjacent elements may have a width, preferably, in a range of 5-50 um, more preferably 15-30 um.

[00379]

P80779801NL1 -57-

[00380] The examples and embodiments described herein serve to illustrate rather than to limit the invention. Elements from different embodiments can be combined to form embodiments not shown in the Figures unless such combinations are non-compatible. The person skilled in the art will be able to design alternative embodiments without departing from the scope of the claims. Reference signs placed in parentheses in the claims shall not be interpreted to limit the scope of the claims.

Items described as separate entities in the claims or the description may be implemented as a single item or multiple hardware items combining the features of the items described.

[00381] It is to be understood that the invention is limited by the annexed claims and its technical equivalents only. In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

[00382] The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the invention. Features of the above described embodiments and aspects can be combined unless their combining results in evident technical conflicts.

[00383]

[00384] In a first aspect, the invention may be summarized as relating to a steerable instrument having a proximal end and a distal end and comprising at least one steering device (168) arranged at said proximal end, and a tubular body (18) extending in a longitudinal direction along a central axis (98) from said proximal end to said distal end,

[00385] said tubular body (18) having an intermediate flexible zone (12a) and at least one distal deflectable zone (17),

[00386] said tubular body (18) including at least one tube element made from a metal, the tube element being provided with a first slotted structure (74) in the flexible zone (12a) and a second slotted structure (72; 106; 136; 156) in the at least one deflectable zone (17),

[00387]the tubular body (18) being provided with tangential rotation blocking elements arranged such as to form a plurality of cable channels (96; 97; 146; 152), each cable channel (96; 97) accommodating one of a plurality of cables (90);

[00388] said cables (90) being connected at said proximal end to said steering device (168) and at said distal end to said deflectable zone (17) to allow deflection of said deflectable zone (17) by means of said steering device (168).

[00389] In that steerable instrument said at least one tube element may be an intermediate tube element (88; 88a; 88b; 88c; 88d; 88e) which

P80779801NL1 -58- e is arranged in at least a portion of said tubular body (18), e has an inner surface and an outer surface, said inner surface surrounding a first channel (84), e comprises said second slotted structure (106) to provide said intermediate tube element (88; 88a; 88b; 88c; 88d; 88e) with at least one deflectable section, and e is configured in at least one of the following shapes to provide said tangential rotation blocking means: a. said outer surface has a corrugated cross section along its entire length defining said plurality of first cable channels (98) each one accommodating at least a portion of one cable (90), and b. said inner surface has a corrugated cross section along its entire length defining said plurality of second cable channels (87) each one accommodating at least a portion of one cable (90).

[00390] That steerable instrument may be configured to have said plurality of first cable channels (96) each one accommodating at least said portion of one cable (90), wherein the tubular body (18) is provided with an outer tube element (86; 130; 134; 150) enclosing said intermediate tube element (88; 88a; 88h; 88c; 88d) such as to cover said plurality of first cable channels (96).

[00391] In that steerable instrument said outer tube element (86; 130; 134; 150) may be provided with at least one of a first outer tube element slotted structure (72; 136) in said distal deflectable zone (17) and a second outer tube element slotted structure (74) in said intermediate flexible zone (12a).

[00392] In that steerable instrument said outer tube element (150) may be shaped such as to form a plurality of third cable channels (151), each third cable channel (151) opposing one first cable channel (96) such as to form together a fourth cable channel (152) accommodating one cable (90).

[00393] In that steerable instrument adjacent to said plurality of first cable channels (96), said outer surface of said intermediate tube element (88; 88a; 88d) may touch said outer tube element (86; 130; 150) in areas of contact such that said plurality of first cable channels (96) have tapered portions in said areas of contact, said tapered portions being at least partly filled with a material in order to prevent cables (90) from getting stuck in said tapered portions.

[00394] Tin that steerable instrument said material may be at least one of portions of said outer tube element (130) extending inwardly towards said central axis and a liner (142) may be arranged between said intermediate tube element (88a) and outer tube element (130).

[00395] In that steerable instrument said outer tube element (86; 134; 150) may have a uniform thickness along its entire length.

[00396] In that steerable instrument said outer tube element (86; 134; 150) may be attached to said intermediate tube element (88; 88a; 88d) at least at one or more locations (75) at a proximal end of said deflectable section.

P8077901NL4 -59-

[00397] In that steerable instrument said intermediate tube element (88; 88a; 88d) may have a cross section structure with a uniform thickness along its entire length such that said outer surface and inner surface have a same corrugated structure.

[00398] That steerable instrument may be configured to have said plurality of second cable channels (97) each one accommodating at least said portion of one cable (80), wherein the tubular body (18) is provided with an inner tube element (92) arranged within said intermediate tube element (88) such as to cover said plurality of second cable channels (87).

[00399] In that steerable instrument said intermediate tube element (88e) may have a cross section structure with a uniform thickness along its entire length such that said outer surface and inner surface have a same corrugated structure, said intermediate tube element (88e) comprising outer portions (88e2) forming an outer circumference of said intermediate tube element (88e), and inner portions (88e1} each shaped such as to enclose an essentially closed channel (96).

[00400] In that steerable instrument at least one of said cables (90) may be enclosed in a separate tube (142).

[00401] In that steerable instrument said at least one tube element may be an outer tube element (134; 134a) surrounding an intermediate tube element (88b) which is arranged in at least a portion of said tubular body (18), and has an inner surface and an outer surface, said inner surface surrounding a first channel (94), and said outer surface has a corrugated cross section along its entire length forming said plurality of first cable channels (96a; 96b) each one accommodating at least a portion of one cable (90).

[00402] In that steerable instrument said at least one tube element may be an outer tube element (134), the steerable instrument also comprising an inner tube element (92), said cables being arranged between said inner tube element (2) and said outer tube element (134), said tangential rotation blocking elements being implemented by at least one of: + a first set of flexible tubes (131) each one accommodating one cable (90) and of which at least some are attached to at least one of said outer tube element (134) and inner tube element (92) at predetermined longitudinal distances, e a set of second flexible tubes (133) configured as tangential spacers between adjacent cables (90) of which at least some are attached to at least one of said outer tube element (134) and inner tube element (92) at predetermined longitudinal distances, and e a set of lips (149) bent inwardly from said outer tube element (134) to said inner tube element (92) and configured as tangential spacers between adjacent cables (90).

[00403] A further aspect relates to a method of manufacturing a flexible tube element comprising the following actions: a. providing a tube element (88; 88a; 88b; 88c; 88d; 88e) which has an inner surface

P80779801NL1 -60- and an outer surface, said inner surface surrounding a channel (94), wherein said tube element (88; 88a; 88b; 88c; 88d; 88e) is configured in at least one of the following shapes: e said outer surface has a corrugated cross section along its entire length defining a plurality of first cable channels (96; 96a; 96b) each one arranged to accommodate at least a portion of one cable (90), and e said inner surface has a corrugated cross section along its entire length defining a plurality of second cable channels (97) each one arranged to accommodate at least a portion of one cable (90), b. manufacturing at least one slotted structure (72; 74; 106; 156) in said tube element (88; 88a; 88h; 88c; 88d; 88e) to provide said tube element (88; 88a; 88b; 88c; 88d; 88e) with at least one deflectable section.

[00404] In that method the tube element may be made from a metal and the at least one slotted structure may be made by either laser or water cutting.

[00405] In that method the laser cutting is performed by directing a laser beam perpendicular to said outer surface of said tube element.

[00406] That method may include manufacturing from said flexible tube element a steerable instrument having a proximal end and a distal end by providing at least one steering device (168) at said proximal end, providing one or more cables and connecting said one or more cables to said steering device (168) at the proximal end and to said deflectable section to allow deflection of said deflectable section by means of said steering device (168).

[00407] A further aspect relates to a steerable instrument having a proximal end and a distal end and comprising at least one steering device (168) arranged at said proximal end, a tubular body (18) surrounding a first channel (94) extending in a longitudinal direction along a first central axis (98) from said proximal end to said distal end, the tubular body (18) having a flexible zone (12a) and at least one deflectable zone (17) arranged distally from said flexible zone (12a), said at least one deflectable zone (17) being connected to said steering device (168) by one or more cables (90) allowing deflection of said at least one deflectable zone (17) by said steering device (168), said steering device (168) comprising: e a supporting member (172) having a second channel (173) having a second central axis arranged in line with said first central axis, said second channel (173) extending from a distal side to a proximal side of the supporting member (172), the tubular body (18) extending distally from the supporting member (172), the supporting member (172) having a ball-shaped member (181) arranged around said second channel (173) at the proximal side of the supporting member (172); e a steering member (180) having a cable fastening mechanism (175) connected to said one or more cables (90), and being rotationally arranged on said ball-shaped member (181) such as to allow either pulling or relaxing said one or more cables (90).

P80779801NL1 -81-

[00408]In that steerable instrument said steering member (180) may have a partially ball-shaped outer surface rotationally supported by said supporting member (172) such that the steering member (180) can rotate within a hollow space (174) of said supporting member (172).

[00409]In that steerable instrument said steering member (180) may have a third channel (179) having a third central axis in line with said first and second central axes, a hollow tube (183) extending proximally from said steering member (179) which hollow tube (183) surrounds a fourth channel along a fourth central axis in line with said first, second and third central axes.

[00410] In that steerable instrument said second channel (173) may have a conically shaped space (177) towards a proximal end of said ball-shaped member (181).

[00411] In that steerable instrument said steerable instrument may comprise a handle (3) at said proximal end, a tool (2) at said distal end and an actuation cable (184) extending from said handle (3) to said tool to allow operation of said tool (2) by operating said handle (3).

[00412] In that steerable instrument said handle (3) may be provided with a rotatable knob (186) which is arranged such that rotation of said rotatable knob (186) results in rotation of said tool (2) while said tool (2) keeps its orientation even if said tubular body (18) is bent at one or more locations.

[00413] That steerable instrument may comprise at least one intermediate tube element (88; 88a; 88b; 88c; 88d; 88e) which e is arranged in at least a portion of said tubular body (18), e has an inner surface and an outer surface, said inner surface surrounding said first channel (94), e comprises at least one slotted structure (108) to provide said intermediate tube element (88; 88a; 88b; 88c; 88d; 88e) with at least one deflectable section aligned with said deflectable zone (17), and e is configured in at least one of the following shapes: a. said outer surface has a corrugated cross section along its entire length defining a plurality of first cable channels (96; 96a; 96b) each one accommodating at least a portion of one cable (90), and b. said inner surface has a corrugated cross section along its entire length defining a plurality of second cable channels (97) each one accommodating at least a portion of one cable (90).

Claims

CONCLUSIONS

A cylindrical element with a hinge structure having a central axis, comprising: a first portion (524; 1124; 522 (n-1); 1122 (n-1)); a second portion (522 (1); 1122 (1); 522 (n); 1122 (n)) located the same distance from the central axis as the first portion and from the first portion (524; 1124; 522 (n-1); 1122 (n-1)) is rotatable about two rotational portions (530 (1); 1130 (1}; 530 (n); 1130 (n)) arranged in locations relative to are rotated 180 ° from each other, viewed in a tangential direction of the cylindrical element; an adhesive element (502 (1); 1006; 502 (n)); wherein the rotation portions (530 (1); 1130 (1); 530 (n ); 1130 (n)) are implemented by: either the first portion (524; 1124; 522 (n-1); 1122 (n-1)) or the second portion (522 (1); 1122 (1) ; 522 (n); 1122 (n)) has an opening that receives a pin (556 (1); 1156 (1); 556 (n); 1156 (n)); the pin (556 (1}; 1156 (1); 556 (n); 1156 (n)) is bonded to portion of the adhesive element (502 (1); 10086; 502 (n)); the other one of the first portion (524; 1124; 522 ( n-1); 1122 (n-1)) and the second part lte (522 (1); 11221); 522 (n); 1122 (n)) is bonded to another portion of the adhesive element (502 (1); 10086; 502 (n)); such that the first portion (524; 1124; 522 (n-1); 1122 (n-1)) and the second portion (522 (1); 11221); 522 (n); 1122 (n)) cannot move relative to each other in a longitudinal direction, a tangential direction, and a radial direction, but are configured to rotate relative to each other about a center of rotation.

The cylindrical element of claim 1, wherein the bonding element is a hinge portion (502 (1); 502 (n)) of a further hinge structure in a further cylindrical element (500) located within the cylindrical element.

The cylindrical element of claim 1, wherein the bonding element is a tangential spacer element (1006) between adjacent control strips (1004) in a further cylindrical element located within the cylindrical element.

The cylindrical element of any preceding claim, wherein the opening is a circular opening having a center forming the center of rotation and the pin (556 (1); 556 (n)) is arranged in the opening such that it is rotatable about the center of rotation.

Cylindrical element according to any of the preceding claims 1-3,

wherein the opening is a circular slot (1158 (1); 1158 (n)) arranged along an arc of a circle having a center forming the center of rotation, the pin (1156 (1); 1156 (n) arranged in the slot such that it is movable in the slot along the arc of the circle.

A cylindrical element according to any of the preceding claims, wherein the pin is a disc cut from material surrounding the opening.

A steerable instrument comprising a cylindrical element according to any one of the preceding claims.

The steerable instrument of claim 7 when dependent on claim 3, wherein the steerable instrument comprises a steerable distal end portion by means of the control strips, the control strips (1004) being longitudinal elements cut from the further cylindrical element (1000) .

A steerable instrument according to claim 8, wherein the tangential spacer element (1006) is a portion cut from the further cylindrical element (1000).

A method of manufacturing a cylindrical element with a hinge structure, comprising: a first portion (524; 1124; 522 (n-1); 1122 (n-1)); a second portion (522 (1}; 1122 (1); 522 (n); 1122 (n)) that is the same distance from the center axis as the first portion and from the first portion (524; 1124; 522 (n-1); 1122 (n-1)) is rotatable about two rotational portions (530 (1); 11301); 530 (n); 1130 (n)) arranged in locations relative to each other Rotated 180 °, viewed in a tangential direction of the cylindrical element; an adhesive element (502 (1); 1006; 502 (n)); wherein the rotation portions (530 (1); 1130 (1); 530 (n); 1130 (n)) are implemented by: either the first portion (524; 1124; 522 (n-1); 1122 (n- 1)) or the second portion (522 (1); 11221); 522 (n); 1122 (n)) has an opening that receives a pin (556 (1); 1156 (1); 556 (n); 1156 (n)); the pin (556 (1}; 11561); 556 (n); 1158 (n)) is attached to portion of the bonding member (502 (1); 1008; 502 (n)); the other one of the first portion (524; 1124; 522 (n-1); 1122 (n-1)) and the second portion (522 (1); 1122 (1); 522 (n); 1122 (n} )) is bonded to another portion of the adhesive element (502 (1); 1006; 502 (n)); such that the first portion (524; 1124; 522 (n-1); 1122 (n-1)) and the second portion (522 (1); 40 11221); 522 (n); 1122 (n)) cannot move relative to each other in a longitudinal direction, a tangential direction and a radial direction, but are configured to rotate relative to each other about a center of rotation; the method comprising having the first portion (524; 1124; 522 (n-1); 1122 (n-1)) and the second portion (522 (1); 1122 (1); 522 (n); 1122 (n )) are formed from a single cylindrical element (520; 1100) by cutting a predetermined pattern from the cylindrical element, for example, by laser cutting or water cutting.

A method according to claim 10, comprising inserting a further cylindrical element (500; 1000) within the single cylindrical element (520; 1100) which further cylindrical element (500; 1000) and the bonding element (502 (1); 1006; 502) (n)), and then bonding the pin (556 (1); 1156 (1); 556 (n); 1156 (n)) to a portion of the adhesive member (502 (1); 1006; 502 ( n)), and bonding the other one of the first portion (524; 1124; 522 (n-1); 1122 (n-1)) and the second portion (522 (1); 1122 (1); 522 (n}; 1122 (n)) to another portion of the adhesive element (502 (1}; 1006; 502 (n)).

A method according to claim 10 or 11, comprising breaking one or more breaking elements that still adhere the pin (556 (1); 115611}; 556 (n); 1156 (n)) to surrounding material of the single cylindrical element ( 520; 1100) during insertion of the further cylindrical element (500; 1000) within the single cylindrical element (520; 1100), and wherein breaking is performed after bonding the pin (556 (1); 1156 (1) ; 556 (n); 1156 (n}) to a portion of the bonding member (502 (1); 1006; 502 (n)), and bonding the other one of the first portion (524; 1124; 522 (n -1); 1122 (n-1)) and the second portion (522 (1); 1122 (1); 522 (n); 1122 (n)) to another portion of the adhesive element (502 (1); 1006 ; 502 (n)).

A method according to any of claims 9-12, comprising operations for producing the steerable instrument according to any of claims 7-9.