Flexible shaft, flexible endoscopic instrument and method for manufacturing a flexible shaft for a flexible endoscopic instrument

Abstract

The present invention provides a flexible shaft (1) for a flexible endoscopic instrument, comprising: a shaft structure (2) having a distal end (3) and a proximal end (4), wherein the shaft structure (2) is supported by at least one strengthening member (5) for bearing axial and / or torque loads applied on the shaft structure (2), wherein the at least one strengthening member (5) extends between the proximal end (4) and the distal end (3). Further the present invention provides a flexible endoscopic instrument (100) comprising such a flexible shaft (1) as well as a method for manufacturing a flexible shaft for a flexible endoscopic instrument.

Description

[0001] 2023P00167 LU

[0002] KARL STORZ SE & Co . KG

[0003] - 1-

[0004] Flexible shaft , flexible endoscopic instrument and method for manufacturing a flexible shaft for a flexible endoscopic instrument

[0005] TECHNICAL FIELD

[0006] The present invention pertains to a flexible shaft for a flexible endoscopic instrument as well as a flexible endoscopic instrument with such a flexible shaft . Furthermore , the present invention pertains to a method for manufacturing a flexible shaft for a flexible endoscopic instrument , in particular for manufacturing such a flexible shaft .

[0007] BACKGROUND

[0008] Surgical tube shaft instruments such as flexible endoscopic instruments are used for a variety of applications in medicine and technology . Such flexible endoscopic instruments comprise a flexible elongated shaft which is suitable for insertion into a cavity, such as an internal body cavity or a cavity of a technical obj ect . As a rule , an endoscopic instrument lens is arranged at the tip of the endoscopic instrument shaft to generate an image of a scene in the observed cavity . To record and transmit the endoscopic image from the distal ( i . e . far from the observer ) to the proximal ( i . e . close to the observer ) end region of the endoscopic instrument , an ordered bundle of optical fibers running inside the shaft can be provided, for example , or an electronic image sensor, such as a CCD chip, which is arranged in the region of the distal end of the shaft and whose signals are transmitted to the proximal end region via electrical lines running inside the shaft . Since there is usually not enough light in the observed cavity, a light guide system can also 2023P00167 LU

[0009] KARL STORZ SE & Co . KG

[0010] -2- be arranged inside the shaft to transport light to the distal end of the endoscopic instrument , where it is used to illuminate the cavity . Further, the endoscopic instrument shaft may include one or more working channels for passing endoscopic working instruments from the proximal to the distal end portion of the shaft for performing manipulations within the cavity .

[0011] Surgical tube shaft instruments are also known which comprise a flexible elongated shaft which is also suitable for insertion into a cavity, such as an internal body cavity or a cavity of a technical obj ect . Such a flexible endoscopic instrument can be used to carry out manipulations in the cavity and for this purpose can be designed, for example , as a grasping instrument for grasping and manipulating tissue or obj ects in the cavity inside the body or in the cavity of a technical obj ect . For this purpose , a tool is arranged at the distal end of the shaft , which can be operated from the proximal end of the shaft via a transmission means running inside the shaft . Such a flexible endoscopic instrument usually does not have its own optics for recording an endoscopic image , but can be used in particular together with a flexible endoscopic instrument .

[0012] It is often desirable to be able to angle the distal end of the shaft , i . e . the tip of the endoscope or endoscopic instrument , in order to facilitate the insertion of the endoscope or endoscopic instrument through a non- flexible endoscopic instrument through a non-rectilinear channel , to be able to move the tip within a cavity in a lateral direction and to be able to change the viewing direction of an optical system arranged in the endoscopic instrument tip or the working direction of a tool arranged at the tip of the endoscopic 2023P00167 LU

[0013] KARL STORZ SE & Co . KG

[0014] -3- instrument . For this purpose , the shaft has a controllable section, in particular a controllable end section, which can be actively angled by a desired amount in a desired direction and can be controlled for this purpose from the proximal end of the endoscopic instrument . The shaft for a flexible endoscopic instrument need not itsel f have a tool and a transmission means , but can for example comprise a working channel into which a flexible endoscopic working instrument which cannot be actively angled and which has such a tool can be inserted up to the distal end of the shaft and possibly beyond, so that the flexible working instrument can be angled with the aid of the shaft .

[0015] The flexible shaft is usually part of the flexible endoscope , which trans fers the torque and force from a handle to a distal section . Since the flexible shaft is hollow it protects also the internal components , like the working channel , light / imager cables , springs and / or push-pull wires . The vertebrae respectively flexible shaft is actuated usually through lever, which is pulling the wire ropes or push-pull wires , respectively . In order to enable controllable articulation of a section of a shaft of a flexible endoscope , it is known to form the latter with a basic structure comprising individual segments which can be pivoted relative to one another and which can be actuated by the push-pull wires , like cable pulls or Bowden cables , guided in the endoscope shaft . In particular, handwheels arranged on the endoscope handle are provided for actuation .

[0016] On urology field the vertebrae and the distal tip visibility under X-ray is helpful and in some applications essential . 2023P00167 LU

[0017] KARL STORZ SE & Co . KG

[0018] -4-

[0019] For example , document US 2024 / 0008721 Al describes an endoscope comprising a bending section body having hinges and a steering wire attached to a segment of the bending section body proximally of at least a distal-most hinge .

[0020] In document US 2005 / 0131279 Al each segment of a controllable section of the endoscope shaft is pivotably mounted relative to the next or previous segment . Four cables are provided for angling the shaft section or endoscope tip in question, which are guided from a proximally arranged control device to the endoscope tip . The cables run in the edge area of the segments and are each of fset by 90 ° to one another with respect to a longitudinal axis , so that the endoscope tip can be steered in a desired direction by rolling up the corresponding cables in the control device .

[0021] However, each cable is guided in a tiny through-hole running along the shaft such that manufacturing and in particular assembling of the flexible shaft is di f ficult and / or lengthy . Current one-piece inj ection molded shafts on the market usually have complex molds to make round cable guide holes through the whole shaft .

[0022] DISCLOSURE OF THE INVENTION

[0023] It is an obj ect of the present invention to provide a flexible shaft , which can simpli fy an assembling process of endoscopic instrument and tolerate torque loads .

[0024] According to the invention, this problem is solved by a flexible shaft for a flexible endoscopic instrument with the features of claim 1 , by a flexible endoscopic instrument with 2023P00167 LU

[0025] KARL STORZ SE & Co . KG

[0026] -5- the features of claim 12 and / or by a method for manufacturing a flexible shaft for a flexible endoscopic instrument with the features of claim 13 .

[0027] According to a first aspect of the invention, a flexible shaft for a flexible endoscopic instrument is provided . The flexible shaft comprises a shaft structure having a distal end and a proximal end, wherein the shaft structure is supported by at least one strengthening member for bearing axial and / or torque loads applied on the shaft structure , wherein the at least one strengthening member extends between the proximal end and the distal end .

[0028] According to a second aspect of the invention, a flexible endoscopic instrument is provided . The flexible endoscopic instrument comprises a flexible shaft according to the first aspect of the invention and an operating interface , which is arranged at the proximal end of the flexible shaft and configured to operate the flexible shaft .

[0029] According to a third aspect of the invention, a method for manufacturing a flexible shaft for a flexible endoscopic instrument , in particular for manufacturing a flexible shaft according to the first aspect of the invention, is provided . The method comprises the steps of :

[0030] Primary shaping of a shaft structure having a distal end and a proximal end .

[0031] Supporting the shaft structure by at least one strengthening member for bearing axial and / or torque loads applied on the shaft structure , wherein the at least one strengthening member extends between the proximal end and the distal end . 2023P00167 LU

[0032] KARL STORZ SE & Co . KG

[0033] - 6-

[0034] A fundamental concept of the invention is to provide a flexible endoscope working vertebrae or shaft , respectively, that is cheaper and quicker to manufacture and also tolerates torque loads . In other words , the at least one strengthening member can extend from the proximal end to the distal end . In particular, the at least one strengthening member can be configured to absorb mechanical loads , for example axial and / or torque loads applied on the shaft structure .

[0035] A particular advantage in the solution according to an aspect of the invention is that a manufacturing of the flexible shaft can be more simpli fied and / or longer lasting .

[0036] The working channel can be inserted into a tubular shaft of the flexible endoscopic instrument . The working channel is mounted or guided at least at an end, in particular an proximal end, of a rod in the flexible endoscopic instrument . In particular, the rod is mounted or guided in the tubular shaft in such a way that the working channel cannot move or rotate axially relative to the tube shaft .

[0037] I f the flexible endoscopic instrument is to be operated by a user such as a surgeon, the flexible endoscopic instrument comprises a handle as a grip for the user . The operating interface then transmits a force or torque , which is applied by the user to the handle via a suitable actuation ( e . g . movable handle leg) , to a force transmission element for examp 1 e .

[0038] I f the flexible endoscopic instrument is to be connected to a robot , the flexible endoscopic instrument comprises a corresponding connection interface for the robot , which can ap- 2023P00167 LU

[0039] KARL STORZ SE & Co . KG

[0040] -7- ply an axial force or torque to the force transmission element via the operating interface .

[0041] Advantageous embodiments and further developments emerge from the description with reference to the figures .

[0042] According to some embodiments of the invention, the at least one strengthening member is arranged at a lateral side of the shaft structure . In case the flexible shaft comprises two strengthening members , the two strengthening members can be arranged at two opposing lateral sides of the shaft structure .

[0043] According to some further embodiments of the invention, the at least one strengthening member is integrated in a wall of the shaft structure . In case the flexible shaft comprises two strengthening members , the two strengthening members can be integrated into two opposing lateral sides of the wall of the shaft structure .

[0044] According to some further embodiments of the invention, the shaft structure is configured at least sectionwise to be articulatable at least in one plain .

[0045] According to some further embodiments of the invention, the shaft structure is made of a polymer material including a X- ray fluorescence additive for X-ray visibility . For example , the X-ray fluorescence additive comprises Bismuth subcarbonate , Bismuth oxychloride , Barium sul fate and / or tungsten . The X-ray fluorescence additive can be added to the polymer material in a powder form . The polymer material can comprise or be made of polyurethane , polyimide , polyether ether ketone or the like . 2023P00167 LU

[0046] KARL STORZ SE & Co . KG

[0047] - 8-

[0048] According to some further embodiments of the invention, the X-ray fluorescence additive has a mass percentage in the polymer material of about 60 % or less , in particular of about 40 % or about 20 % . Thus , mechanical properties of the shaft structure would not be af fected drastically .

[0049] For example , the flexible shaft is configured as a single use flexible endoscope vertebrae . In particular, the flexible shaft comprises an one-piece single use flexible endoscope articulation on the distal end .

[0050] According to some further embodiments of the invention, the shaft structure comprises a cutout , which extends in a circumferential direction of the shaft structure without crossing the at least one strengthening member . For example , the shaft structure comprises a plurality of cutouts , which are arranged in series along a longitudinal axis between the proximal end and the distal end . In particular, a holding unit is arranged between two adj acent cutouts of the plurality of cutouts . Each of the plurality of cutouts can extend in a circumferential direction of the shaft structure .

[0051] According to some further embodiments of the invention, the flexible shaft further comprises a coating, which is disposed on an outer surface of the shaft structure . The coating may also cover a cutout in the shaft structure .

[0052] According to some further embodiments of the invention, the shaft structure is configured as one piece , which is manufactured by an extrusion process , wherein the at least one strengthening member is extruded in the same extrusion process or a wall of the shaft structure has a through-opening 2023P00167 LU

[0053] KARL STORZ SE & Co . KG

[0054] - 9- for receiving the at least one strengthening member . Hence , a manufacturing of the flexible shaft can be quick and easy, when the shaft structure and the at least one strengthening member are both extruded in during one extrusion process .

[0055] According to some further embodiments of the invention, the shaft structure is formed by at least two parts that are coupled together, wherein the at least one strengthening member is arranged at a contact area of the at least two parts . For coupling the shaft structure the at least two parts can be materially bonded together, in particular materially bonded by ultrasonic welding .

[0056] For example , the contact area can be materially bonded together . The at least one strengthening member can be attached to the shaft structure by a form fit or by a press fit or both .

[0057] According to some further embodiments of the invention, the shaft structure is manufactured by an inj ection molding process . As a result , a manufacturing of the flexible shaft , in particular a manufacturing of an inj ection mold, can be simpler and / or longer lasting . In particular, the at least two parts of the shaft structure are manufactured by an inj ection molding process .

[0058] Additionally, the shaft structure can comprise a through- opening, which is configured for receiving a working channel and / or an optical image device , wherein the through-opening can extend through the shaft structure from the proximal end to the distal end . 2023P00167 LU

[0059] KARL STORZ SE & Co . KG

[0060] - 10-

[0061] Alternatively or additionally, the shaft structure can comprise tunnels for receiving a steering wire .

[0062] Optionally, the flexible endoscopic instrument can further comprise a distal tip, which is materially bonded to the distal end of the shaft structure . For example , the distal tip can be bonded to the distal end by an ultraviolet adhesive . The distal tip can comprise a tool respectively accessory, which can be moved by the axial force or torque transmitted via steering wires or push-pull wires , respectively, inside and opposite the shaft structure . The tool can be configured as a clamp, plier, tweezer, gripper, scissors and the like . In particular, the tool can also be configured to be operated monopolar or bipolar, for example to cut or cauteri ze tissue and the like .

[0063] The shaft structure can be based on an extruded profile , for example . That means , the shaft structure can be manufactured by an extrusion process . For example , the working channel can be loaded into the shaft structure by pushing the working channel into the shaft structure .

[0064] Optionally, the shaft structure can be elastically deformable at least in an area of the slot .

[0065] The operating interface and / or the flexible endoscopic instrument can be made of a plastic material . For example , the flexible endoscopic instrument can be completely made of a plastic material , in particular when the flexible endoscopic instrument is intended to be used only once .

[0066] Optionally, the shaft structure comprises a plurality of shaft sections arranged in series . The plurality of shaft 2023P00167 LU

[0067] KARL STORZ SE & Co . KG

[0068] - 11- sections arranged in series correspond to an active bending section of the flexible endoscopic instrument .

[0069] The plurality of shaft sections can be connected by an integrated connecting bar, which connects adj acent shaft sections such that they are articulatable in one plain . For example , each shaft section can be configured as a vertebral member, which is coupled to the adj acent vertebral member such that pivoting of the vertebral member relative to the adj acent vertebral member in a radial axis is provided . For example , the shaft structure can comprise a circular or oval shape . Thereby, the shaft structure can have a constant diameter . A cross section of the shaft structure can have an oval shape in order to reduce intra renal pressure and / or to provide natrium chloride circulation during operation, in particular on urology field .

[0070] Optionally, the shaft structure can comprise an inner shaft structure layer . The inner shaft structure layer may comprise a slot for laterally opening the inner shaft structure layer, wherein the slot is arranged at least sectionwise between the proximal end and the distal end . For example , the inner shaft structure layer can have an inner surface and an outer surface facing away from the inner surface , wherein the slot extends radially from the outer surface to the inner surface . Thus , the slot splits the inner shaft structure layer through its complete thickness . In particular, the slot can be arranged at a lateral side of the inner shaft structure layer or at two opposing lateral sides of the inner shaft structure layer .

[0071] For example , the inner shaft structure layer can have a recess or tunnel , which penetrates the inner shaft structure 2023P00167 LU

[0072] KARL STORZ SE & Co . KG

[0073] - 12- layer on two opposing sides with respect to the slot in an alignment . Thus , any longitudinal body, for example a pin, can be put into the recess or tunnel for securing the slot against opening . That means , the inner shaft structure layer comprises a mechanical lock formed by the longitudinal body . A wire , which can be inserted through the tunnel can lock the slot .

[0074] Further, the shaft structure can comprise an outer shaft layer, which is disposed on the outer surface of the inner shaft structure layer . Hence , the outer shaft layer can support the inner shaft structure layer . The outer shaft layer can be configured as a coating that at least partly encloses the inner shaft structure layer . Moreover, the inner shaft structure layer and the outer shaft layer can be bonded together materially . Alternatively or additionally, the inner shaft structure layer and the outer shaft layer can have a press fit . For example , the outer shaft layer can be configured as a plastic cover to give the flexible shaft biocompatibility and tightness .

[0075] Moreover, the flexible endoscopic instrument can further comprise a working channel for communicating fluids or medical tools from the operating interface to the distal end of the shaft .

[0076] For example , the flexible shaft can be loaded with the working channel through the slot . By providing the inner shaft structure layer or internal profile , respectively, all main components of the flexible endoscopic instrument can be accommodated in the inner shaft structure layer . Hence , loading of the components of the flexible shaft can be at least partly automated . Furthermore , an easier and faster assembly 2023P00167 LU

[0077] KARL STORZ SE & Co . KG

[0078] - 13- of the working channel and / or the optical image device can be provided . The inner shaft structure layer can be based on an extruded profile , for example . That means , the inner shaft structure layer can be manufactured by an extrusion process . For example , the working channel can be loaded into the inner shaft structure layer by pushing open the slot .

[0079] According to some further embodiments of the invention, the step of primary shaping comprises an extruding of the shaft structure , wherein the at least one strengthening member is extruded in the same extrusion process of primary shaping or a wall of the shaft structure has a through-opening for receiving the at least one strengthening member, and wherein the step of supporting comprises a pushing of the at least one strengthening member through the through-opening . For example , the at least one strengthening member can be configured as a rod .

[0080] According to some further embodiments of the invention, the step of primary shaping comprises an inj ection molding of at least two parts of the shaft structure and wherein the method further comprises a step of coupling the at least two parts together for forming the shaft structure , wherein the at least one strengthening member is arranged at a contact area of the at least two parts . For coupling the shaft structure the at least two parts can be materially bonded together, in particular materially bonded by ultrasonic welding . For example , the contact area can be materially bonded together . The at least one strengthening member can be attached to the shaft structure by a form fit or by a press fit or both . 2023P00167 LU

[0081] KARL STORZ SE & Co . KG

[0082] - 14-

[0083] Optionally, the method further comprises a step of generating a cutout in the shaft structure by laser cutting or by punching . Hence , a shape of the flexible shaft can be precisely cut after the step of primary shaping the shaft structure .

[0084] In other words , the present invention can provide a flexible endoscope vertebrae design with extruded and laser cut links . A torque stability can be achieved with strengthening members respectively strengthening wires in it . The flexible shaft can have an extruded preferably oval profile with the strengthening wires in it . A suitable laser can be used to shape the structure / cut angles between the links . The strengthening wires can provide strengthness and torque stability . Extruded in wires , such as acting as a mandrel , for push-pull wires can be removed to free the tunnels for push-pull wires or steering wires , respectively . The X-ray fluorescence additive can be used on the plastic respectively polymer material . As a plastic PEEK and Polyimide is considered . This solution allows to create also a shaft , what needs to be covered by an external layer . Alternatively or additionally, the present invention can provide a flexible endoscope vertebrae design where an active section respectively articulatable section can be made from two pieces respectively the at least two parts to improve drastically the manufacturability . During the j oining process the strengthening members , for example an elastic wire or wire rope , can be added . Joining can be done most likely using ultrasonic welding .

[0085] The above embodiments and further developments can be combined with one another arbitrarily, as far as appropriate . Further possible configurations , developments and implemen- 2023P00167 LU

[0086] KARL STORZ SE & Co . KG

[0087] - 15- tations of the invention are also combinations of features of the invention described above or below for the exemplary embodiments that are not explicitly cited . In particular, a person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention .

[0088] BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The present invention is explained more speci fically below on the basis of the exemplary embodiments indicated in the schematic figures , in which :

[0090] Fig . 1 shows an embodiment of a handheld steerable flexible endoscopic instrument according to an embodiment of the invention in an overall view;

[0091] Fig . 2 shows a perspective view of a flexible shaft for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure is configured as one piece ;

[0092] Fig . 3 shows a perspective view of a flexible shaft for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure is configured as one piece and has tunnels for receiving a steering wire ;

[0093] Fig . 4 shows a cut view of the flexible shaft of Fig . 3 ;

[0094] Fig . 5 shows a perspective view of a flexible shaft for a flexible endoscopic instrument according to a further embod- 2023P00167 LU

[0095] KARL STORZ SE & Co . KG

[0096] - 16- iment of the invention, wherein the shaft structure is formed by at least two parts that are coupled together ;

[0097] Fig . 6 shows a front view of the flexible shaft of Fig . 5 ;

[0098] Fig . 7 shows a schematic flow chart of a method for assembling a working channel and / or an optical image device to a shaft for a flexible endoscopic instrument according to a further embodiment of the invention;

[0099] Fig . 8 shows a cut view of the flexible shaft of Fig . 3 , wherein the flexible shaft comprises a slot ;

[0100] Fig . 9 shows a cut view of the flexible shaft of Fig . 3 , wherein the flexible shaft comprises two slots at opposing lateral sides ;

[0101] Fig . 10 shows a perspective view of a flexible shaft for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure has a slot and tunnels for receiving a wire ;

[0102] Fig . 11 shows a perspective view of a flexible shaft for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure has two slots at opposing lateral sides and tunnels for receiving a wire .

[0103] The accompanying figures are intended to convey a further understanding of the embodiments of the invention . They illustrate embodiments and are used in conj unction with the description to explain principles and concepts of the inven- 2023P00167 LU

[0104] KARL STORZ SE & Co. KG

[0105] -17- tion. Other embodiments and many of the cited advantages emerge in light of the drawings. The elements of the drawings are not necessarily shown to scale in relation to one another. Direction-indicating terminology such as for example "at the top", "at the bottom", "on the left", "on the right", "above", "below", "horizontally", "vertically", "at the front", "at the rear" and similar statements are merely used for explanatory purposes and do not serve to restrict the generality to specific configurations as shown in the figures .

[0106] In the figures of the drawing, elements, features and components that are the same, have the same function and have the same effect are each provided with the same reference signs - unless explained otherwise.

[0107] DETAILED DESCRIPTION OF DRAWINGS

[0108] Fig. 1 shows an embodiment of a handheld steerable flexible endoscopic instrument 100 in an overall view.

[0109] As shown schematically in Fig. 1, the flexible endoscopic instrument 100 typically comprises a handpiece 101 and a flexible shaft 1, the handpiece 101 being attached to a proximal end of the flexible shaft 1. The handpiece 101 can have an outer housing 102 made of a plastic and / or metallic material. On a lower side of the housing 102 a first hand wheel 103 and a second hand wheel 104 are arranged for controlling a deflection of a steerable section la of the flexible shaft 1, as is described below. Typically the first and the second hand wheel 103, 104 are arranged coaxially, and at an exterior side of the second hand wheel 104 a knob 105 for controlling a deflection brake relating to the second 2023P00167 LU

[0110] KARL STORZ SE & Co . KG

[0111] - 18- hand wheel 104 is provided . Further, the handpiece 101 may exhibit a multiplicity of control buttons 106 for controlling various functions of the flexible endoscopic instrument 100 , such as for controlling the imaging and / or illumination system and / or irrigation and suction pumps , for example . The handpiece 101 may be connectable to an external video unit or a video monitor via connector 107 and to an external light source via light cable 108 . Moreover, an instrument port 109 may be provided for inserting endoscopic instruments to be advanced through one or more respective channels to a distal end of the flexible shaft 1 for manipulating tissue or other obj ects within a cavity into which the flexible shaft 1 can be inserted .

[0112] At its distal end the flexible shaft 1 comprises a steerable section la . The steerable section la may form a distal end section of the flexible shaft 1 or, as shown in Fig . 1 , may carry a distal end cap 11 , which may accommodate an imaging optics and an electronic image sensor for providing an endoscopic image of a cavity into which the flexible shaft 1 is inserted . The image signal generated by the image sensor may be transmitted via electric cables extending through the shaft 1 and the handpiece 101 to the connector 107 for being processed and displayed by an external video unit . The flexible shaft 1 in total is flexible to an extent to be advanced through an endoscopic access or a hollow organ towards a cavity to be observed, being capable of adapting to a curved shape of the access or the organ . The steerable section la, on the other hand, is capable of being flexed actively by turning the hand wheels 103 , 104 . To this end the steerable section la comprises an inner structure of a plurality of shaft sections , thus being deflectable or articulatable in one or more planes . The plurality of shaft 2023P00167 LU

[0113] KARL STORZ SE & Co . KG

[0114] - 19- sections can be covered by a flexible tube to form a smooth outer surface , the flexible shaft 1 in total having a uniform cross-sectional shape and diameter .

[0115] For controlling the deflection of the plurality of shaft sections two counteracting control wires (not shown in Fig . 1 ) are provided extending on opposite sides within the plurality of shaft sections , by a longitudinal movement of which the steerable section la can be bent to one or the other side , as indicated symbolically in Fig . 1 . The control wires extend along the shaft 1 and are connected at their proximal ends to a deflection control mechanism arranged within the handpiece 101 , which can be operated by a user by turning the hand wheels 103 , 104 for deflecting the steerable section la . In the exemplary embodiment shown, the steerable section can be bent or articulated within a first plane that corresponds to the plane of the drawing, a deflection angle being controllable by rotating the first hand wheel 103 . Further, the steerable section la can be bent in a second plane perpendicular to the first plane and perpendicular to the plane of the drawing, a corresponding deflection angle being controllable by rotating the second hand wheel 104 .

[0116] The flexible shaft 1 exemplarily comprises a shaft structure having a distal end 3 and a proximal end 4 . The shaft structure 2 is supported by at least one strengthening member for bearing axial and / or torque loads applied on the shaft structure . The at least one strengthening member extends between the proximal end 4 and the distal end 3 . In other words , the at least one strengthening member extends from the proximal end to the distal end . 2023P00167 LU

[0117] KARL STORZ SE & Co . KG

[0118] -20-

[0119] Fig . 2 shows a perspective view of a flexible shaft 1 for a flexible endoscopic instrument 100 according to a further embodiment of the invention, wherein a shaft structure 2 is configured as one piece .

[0120] The flexible shaft 1 comprises the shaft structure 2 having a distal end 3 and a proximal end 4 . The shaft structure 2 is supported by at least one strengthening member 5 for bearing axial and / or torque loads applied on the shaft structure 2 , wherein the at least one strengthening member 5 extends between the proximal end 4 and the distal end 3 . In other words , the at least one strengthening member extends from the proximal end to the distal end .

[0121] Here , the shaft structure 2 is exemplarily configured as one piece , which is manufactured by an extrusion process , wherein the at least one strengthening member 5 is extruded in the same extrusion process or a wall of the shaft structure 2 has a through-opening for receiving the at least one strengthening member 5 .

[0122] For example , the at least one strengthening member 5 can be arranged at a lateral side of the shaft structure 2 . Here , the at least one strengthening member 5 exemplarily comprises two strengthening members 5 . A first of the two strengthening members 5 can be arranged at an upper lateral side of the shaft structure 2 and a second of the two strengthening members 5 can be arranged at a lower lateral side of the shaft structure 2 . In case the flexible shaft 2 comprises two strengthening members 5 , the two strengthening members 5 can be arranged at two opposing lateral sides , like the upper and the lower lateral side , of the shaft structure 2 , as it is illustrated in Fig . 2 . 2023P00167 LU

[0123] KARL STORZ SE & Co . KG

[0124] -21-

[0125] Furthermore , the at least one strengthening member 5 can be integrated in a wall of the shaft structure 2 . In case the flexible shaft 1 comprises two strengthening members 5 , the two strengthening members 5 can be integrated into two opposing lateral sides of the wall of the shaft structure 2 .

[0126] Optionally, the shaft structure 2 can be configured at least sectionwise to be articulatable at least in one plain .

[0127] Moreover, the shaft structure 2 can be made of a polymer material including a X-ray fluorescence additive for X-ray visibility . For example , the X-ray fluorescence additive comprises Bismuth subcarbonate , Bismuth oxychloride , Barium sul fate and / or tungsten . The X-ray fluorescence additive can be added to the polymer material in a powder form . The polymer material can comprise or be made of polyurethane , polyimide , polyether ether ketone or the like . Thereby, the X-ray fluorescence additive can have a mass percentage in the polymer material of about 60 % or less , in particular of about 40 % or about 20 % .

[0128] Further, the shaft structure 2 may comprise a cutout 6 , which extends in a circumferential direction of the shaft structure 2 without crossing the at least one strengthening member 5 . For example , the shaft structure 2 comprises a plurality of cutouts 6 , which are arranged in series along a longitudinal axis X between the proximal end and the distal end . In particular, a holding unit is arranged between two adj acent cutouts 6 of the plurality of cutouts 6 . Each of the plurality of cutouts 6 can extend in a circumferential direction of the shaft structure 2 . 2023P00167 LU

[0129] KARL STORZ SE & Co . KG

[0130] -22-

[0131] Optionally, the flexible shaft may further comprise a coating (not shown) , which is disposed on an outer surface of the shaft structure 2 . The coating may also cover a cutout 6 in the shaft structure 2 .

[0132] Additionally, the shaft structure 2 can comprise a through- opening 7 , which is configured for receiving a working channel and / or an optical image device , wherein the through- opening 7 can extend through the shaft structure from the proximal end to the distal end .

[0133] Fig . 3 shows a perspective view of a flexible shaft 1 for a flexible endoscopic instrument according to a further embodiment of the invention, wherein a shaft structure 2 is configured as one piece and has tunnels 8 for receiving a steering wire .

[0134] The flexible shaft 1 of Fig . 3 substantially comprises the same features as the flexible shaft 1 of Fig . 2 , but di f fers in that the shaft structure 2 can comprise the tunnels 8 for receiving a steering wire . For example , the tunnels 8 can be arranged at opposite sides of the shaft structure 2 . In particular, the tunnels 8 and the at least one strengthening member 5 can be arranged alternating around the circumference of the shaft structure 2 .

[0135] Fig . 4 shows a cut view of the flexible shaft 1 of Fig . 3 .

[0136] For example , the through-opening for receiving the at least one strengthening member 5 can have a diameter of about 8 mm . Furthermore , the wall of the shaft structure 2 can have a thickness T of about 16 mm . The wall of the shaft struc- 2023P00167 LU

[0137] KARL STORZ SE & Co . KG

[0138] -23- ture 2 around the through-opening can have a thickness of about 4 mm .

[0139] The shaft structure 2 can have an oval shape , wherein a width W of the shaft structure 2 can be in the range of about 98 mm to about 94 mm, in particular can be of about 96 mm . Additionally or alternatively, a height H of the shaft structure 2 can be in the range of about 114 mm to about 110 mm, in particular can be of about 112 mm .

[0140] The tunnels 8 can have a diameter of about 12 mm, for example . The wall of the shaft structure 2 around the tunnels 8 can have a thickness of about 5 mm .

[0141] Fig . 5 shows a perspective view of a flexible shaft 1 for a flexible endoscopic instrument 100 according to a further embodiment of the invention, wherein a shaft structure 2 is formed by at least two parts 2a, 2b that are coupled together . Fig . 6 shows a front view of the flexible shaft 1 of Fig . 5 .

[0142] The flexible shaft 1 comprises the shaft structure 2 having a distal end 3 and a proximal end 4 . The shaft structure 2 is supported by at least one strengthening member 5 for bearing axial and / or torque loads applied on the shaft structure 2 , wherein the at least one strengthening member 5 extends between the proximal end 4 and the distal end 3 . In other words , the at least one strengthening member extends from the proximal end to the distal end .

[0143] Here , the shaft structure 2 is exemplarily formed by at least two parts 2a, 2b that are coupled together, wherein the at least one strengthening member 5 is arranged at a 2023P00167 LU

[0144] KARL STORZ SE & Co . KG

[0145] -24- contact area of the at least two parts 2a, 2b . For coupling the shaft structure 2 the at least two parts 2a, 2b can be materially bonded together, in particular materially bonded by ultrasonic welding . For example , the contact area can be materially bonded together . The at least one strengthening member 5 can be attached to the shaft structure 2 by a form fit or by a press fit or both .

[0146] Moreover, the shaft structure 2 can be manufactured by an inj ection molding process . As a result , a manufacturing of the flexible shaft 1 , in particular a manufacturing of an inj ection mold, can be simpler and / or longer lasting . In particular, the at least two parts of the shaft structure are manufactured by an inj ection molding process .

[0147] For example , the at least one strengthening member 5 can be arranged at a lateral side of the shaft structure 2 . Here , the at least one strengthening member 5 exemplarily comprises two strengthening members 5 . A first of the two strengthening members 5 can be arranged at an upper lateral side of the shaft structure 2 and a second of the two strengthening members 5 can be arranged at a lower lateral side of the shaft structure 2 . In case the flexible shaft 2 comprises two strengthening members 5 , the two strengthening members 5 can be arranged at two opposing lateral sides , like the upper and the lower lateral side , of the shaft structure 2 , as it is illustrated in Fig . 2 .

[0148] Optionally, the shaft structure 2 can be configured at least sectionwise to be articulatable at least in one plain .

[0149] Moreover, the shaft structure 2 can be made of a polymer material including a X-ray fluorescence additive for X-ray 2023P00167 LU

[0150] KARL STORZ SE & Co . KG

[0151] -25- visibility . For example , the X-ray fluorescence additive comprises Bismuth subcarbonate , Bismuth oxychloride , Barium sul fate and / or tungsten . The X-ray fluorescence additive can be added to the polymer material in a powder form . The polymer material can comprise or be made of polyurethane , polyimide , polyether ether ketone or the like . Thereby, the X-ray fluorescence additive can have a mass percentage in the polymer material of about 60 % or less , in particular of about 40 % or about 20 % .

[0152] Further, the shaft structure 2 may comprise a cutout 6 , which extends in a circumferential direction of the shaft structure 2 without crossing the at least one strengthening member 5 . For example , the shaft structure 2 comprises a plurality of cutouts 6 , which are arranged in series along a longitudinal axis X between the proximal end and the distal end . In particular, a holding unit is arranged between two adj acent cutouts 6 of the plurality of cutouts 6 . Each of the plurality of cutouts 6 can extend in a circumferential direction of the shaft structure 2 .

[0153] Alternatively or additionally, the shaft structure 2 can comprise tunnels 8 for receiving a steering wire .

[0154] Additionally, the shaft structure 2 can comprise a through- opening 7 , which is configured for receiving a working channel and / or an optical image device , wherein the through- opening 7 can extend through the shaft structure from the proximal end to the distal end .

[0155] Fig . 7 shows a schematic flow chart of a method for manufacturing a flexible shaft 1 for a flexible endoscopic instrument . The flexible endoscopic instrument 100 can be config- 2023P00167 LU

[0156] KARL STORZ SE & Co . KG

[0157] -26- ured as the flexible endoscopic instrument 100 of Fig . 1 , for example .

[0158] The method comprises steps of primary shaping S I of a shaft structure 2 , supporting S2 the shaft structure 2 and optionally coupling S3 at least two parts 2a, 2b of the shaft structure 2 .

[0159] In the step of primary shaping S I , the shaft structure 2 having a distal end 3 and a proximal end 4 is primary shaped . Furthermore , the step of primary shaping S I may comprise an extruding of the shaft structure 2 , wherein the at least one strengthening member 5 is extruded in the same extrusion process of primary shaping or a wall of the shaft structure 2 has a through-opening for receiving the at least one strengthening member 5 . Alternatively or additionally, the step of primary shaping S I can comprise an inj ection molding of the at least two parts 2a, 2b of the shaft structure 2 .

[0160] In the step of supporting S2 , the shaft structure 2 is supported by at least one strengthening member 5 for bearing axial and / or torque loads applied on the shaft structure 2 . The at least one strengthening member 5 extends between the proximal end 4 and the distal end 3 . Optionally, the step of supporting S2 can comprise a pushing of the at least one strengthening member 5 through the through-opening .

[0161] In case the shaft structure 2 has the at least two parts 2a, 2b the method can further comprise a step of coupling S3 the at least two parts 2a, 2b together for forming the shaft structure 2 , wherein the at least one strengthening member 5 is arranged at a contact area of the at least two parts 2a, 2023P00167 LU

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[0163] -27-

[0164] 2b . For coupling the shaft structure 2 the at least two parts 2a, 2b can be materially bonded together, in particular materially bonded by ultrasonic welding . For example , the contact area can be materially bonded together . The at least one strengthening member 5 can be attached to the shaft structure 2 by a form fit or by a press fit or both .

[0165] Optionally, the method further comprises a step of generating a cutout 6 in the shaft structure 2 by laser cutting or by punching . Hence , a shape of the flexible shaft 1 can be precisely cut after the step of primary shaping S I the shaft structure 2 .

[0166] Fig . 8 shows a cut view of the flexible shaft 1 of Fig . 3 , wherein the flexible shaft 1 comprises a slot 9 .

[0167] The flexible shaft 1 of Fig . 8 substantially comprises the same features as the flexible shaft 1 of Fig . 2 or 3 , but di f fers in that the shaft structure 2 additionally comprises the slot 9 and can comprise the tunnels 8 for receiving a wire for locking the slot 9 . For example , the tunnels 8 can be arranged at opposite sides of the shaft structure 2 . In particular, the tunnels 8 and the at least one strengthening member 5 can be arranged alternating around the circumference of the shaft structure 2 .

[0168] Fig . 9 shows a cut view of the flexible shaft 1 of Fig . 3 , wherein the flexible shaft 1 comprises two slots 9 at opposing lateral sides .

[0169] In comparison to the flexible shaft of Fig . 8 , the shaft structure 2 in Fig . 9 comprises two slots 9 at opposing lat- 2023P00167 LU

[0170] KARL STORZ SE & Co . KG

[0171] -28- eral sides . As above , the tunnels 8 can be configured for receiving a wire for locking each slot 9 .

[0172] Fig . 10 shows a perspective view of a flexible shaft 1 for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure 2 has a slot 9 and tunnels 8 for receiving a wire .

[0173] The flexible shaft 1 of Fig . 10 substantially comprises the same features as the flexible shaft 1 of Fig . 3 , but di f fers in that the shaft structure 2 additionally comprises the slot 9 for laterally opening the shaft structure 2 . In particular, the shaft structure 2 can comprise an inner shaft structure layer . The inner shaft structure layer may comprise the slot 9 for laterally opening the inner shaft structure layer, wherein the slot is arranged at least sectionwise between the proximal end and the distal end . For example , the inner shaft structure layer can have an inner surface and an outer surface facing away from the inner surface , wherein the slot extends radially from the outer surface to the inner surface , as it is illustrated in Fig . 8 . Thus , the slot 9 splits the inner shaft structure layer or shaft structure 2 through its complete thickness .

[0174] Fig . 11 shows a perspective view of a flexible shaft 1 for a flexible endoscopic instrument according to a further embodiment of the invention, wherein the shaft structure 2 has two slots 9 at opposing lateral sides and tunnels 8 for receiving a wire .

[0175] The flexible shaft 1 of Fig . 11 substantially comprises the same features as the flexible shaft 1 of Fig . 2 , but di f fers in that the shaft structure 2 additionally comprises the two 2023P00167 LU

[0176] KARL STORZ SE & Co . KG

[0177] -29- slots 9 for laterally opening the shaft structure 2 at opposing lateral sides and comprises the tunnels 8 for receiving a wire for locking the slot 9 . In particular, the shaft structure 2 can comprise an inner shaft structure layer . The inner shaft structure layer may comprise the two slots 9 for laterally opening the inner shaft structure layer, wherein the slot 9 is arranged at least sectionwise between the proximal end and the distal end . For example , the inner shaft structure layer can have an inner surface and an outer surface facing away from the inner surface , wherein the slot extends radially from the outer surface to the inner surface , as it is illustrated in Fig . 9 . Thus , the slot 9 splits the inner shaft structure layer or shaft structure 2 through its complete thickness . For example , the flexible shaft 1 can be loaded with the working channel through the slot 9 .

[0178] As it is exemplarily illustrated in Fig . 11 , the tunnels 8 or recess penetrate the shaft structure 2 on two opposing sides with respect to the slot 9 in an alignment . Thus , any longitudinal body, for example a pin, can be put into the recess or tunnel 8 for securing the slot 9 against opening . That means , the shaft structure 2 comprises a mechanical lock formed by the longitudinal body . A wire (not shown) , which can be inserted through the tunnel 8 can lock the slot 9 .

[0179] In the detailed description above , various features have been combined in one or more examples in order to improve the rigorousness of the illustration . However, it should be clear in this case that the above description is of merely illustrative but in no way restrictive nature . It serves to cover all alternatives , modi fications and equivalents of the 2023P00167 LU

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[0181] -30- various features and exemplary embodiments . Many other examples will be immediately and directly clear to a person skilled in the art on the basis of his knowledge in the art in consideration of the above description .

[0182] The exemplary embodiments have been chosen and described in order to be able to present the principles underlying the invention and their application possibilities in practice in the best possible way . As a result , those skilled in the art can optimally modi fy and utili ze the invention and its various exemplary embodiments with regard to the intended purpose of use . In the claims and the description, the terms " including" and "having" are used as neutral linguistic concepts for the corresponding terms " comprising" . Furthermore , use of the terms " a" , " an" and "one" shall not in principle exclude the plurality of features and components described in this way .

[0183] While at least one exemplary embodiment of the present invention ( s ) is disclosed herein, it should be understood that modi fications , substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure . This disclosure is intended to cover any adaptations or variations of the exemplary embodiment ( s ) . In addition, in this disclosure , the terms "comprise" or "comprising" do not exclude other elements or steps , the terms "a" or "one" do not exclude a plural number, and the term "or" means either or both . Furthermore , characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise . This disclosure hereby incorpo- 2023P00167 LU

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[0185] -31- rates by reference the complete disclosure of any patent or application from which it claims benefit or priority .

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[0188] -32-

[0189] REFERENCE LIST

[0190] 1 flexible shaft

[0191] 2 shaft structure

[0192] 2a, 2b at least two parts of the shaft structure

[0193] 3 distal end

[0194] 4 proximal end

[0195] 5 at least one strengthening member

[0196] 6 cutout

[0197] 7 through-opening for receiving a working channel

[0198] 8 tunnels

[0199] 9 slot

[0200] 100 flexible endoscopic instrument

[0201] 102 operating interface

[0202] 104 tool or accessory

[0203] 105 handle

[0204] 106 movable handle limb

[0205] 107 accessory interface

[0206] S I primary shaping of a shaft structure , and optionally

[0207] S2 supporting the shaft structure

[0208] S3 coupling at least two parts of the shaft structure

[0209] T thickness of the wall

[0210] W width of the shaft structure

[0211] H height of the shaft structure

[0212] X longitudinal axis

Claims

2023P00167 LUKARL STORZ SE & Co. KG-33-CLAIMS1. Flexible shaft (1) for a flexible endoscopic instrument (100) , comprising: a shaft structure (2) having a distal end (3) and a proximal end (4) , wherein the shaft structure (2) is supported by at least one strengthening member (5) for bearing axial and / or torque loads applied on the shaft structure (2) , wherein the at least one strengthening member (5) extends between the proximal end (4) and the distal end (3) .

2. Flexible shaft (1) according to claim 1, c h a r a c t e r i z e d i n t h a t the at least one strengthening member (5) is arranged at a lateral side of the shaft structure (2) .

3. Flexible shaft (1) according to claim 1 or 2, c h a r a c t e r i z e d i n t h a t the at least one strengthening member (5) is integrated in a wall of the shaft structure (2) .

4. Flexible shaft (1) according to one of the preceding claims , c h a r a c t e r i z e d i n t h a t the shaft structure (2) is configured at least sectionwise to be articulatable at least in one plain.

5. Flexible shaft (1) according to one of the preceding claims , c h a r a c t e r i z e d i n t h a t the shaft structure (2) is made of a polymer material including a X-ray fluorescence additive for X-ray visibility.2023P00167 LUKARL STORZ SE & Co. KG-34-6. Flexible shaft (1) according to claim 5, c h a r a c t e r i z e d i n t h a t the X-ray fluorescence additive has a mass percentage in the polymer material of about 60 % or less, in particular of about 40 % or about 20 % .

7. Flexible shaft (1) according to one of the preceding claims , c h a r a c t e r i z e d i n t h a t the shaft structure (2) comprises a cutout (6) , which extends in a circumferential direction of the shaft structure (2) without crossing the at least one strengthening member (5) .

8. Flexible shaft (1) according to one of the preceding claims , f u r t h e r c o mp r i s i n g a coating, which is disposed on an outer surface of the shaft structure (2) .

9. Flexible shaft (1) according to one of the preceding claims , c h a r a c t e r i z e d i n t h a t the shaft structure (2) is configured as one piece, which is manufactured by an extrusion process, wherein the at least one strengthening member (5) is extruded in the same extrusion process or a wall of the shaft structure (2) has a through-opening for receiving the at least one strengthening member (5) .

10. Flexible shaft (1) according to one of the claims 1 to 8, c h a r a c t e r i z e d i n t h a t2023P00167 LUKARL STORZ SE & Co. KG-35- the shaft structure (2) is formed by at least two parts (2a, 2b) that are coupled together, wherein the at least one strengthening member (5) is arranged at a contact area of the at least two parts (2a, 2b) .

11. Flexible shaft (1) according to one of the claims 1 to 8 or 10, c h a r a c t e r i z e d i n t h a t the shaft structure (2) is manufactured by an injection molding process.

12. Flexible endoscopic instrument (100) , comprising: a flexible shaft (1) according to one of the preceding claims; and an operating interface, which is arranged at the proximal end (4) of the flexible shaft (1) and configured to operate the flexible shaft (1) .

13. Method for manufacturing a flexible shaft for a flexible endoscopic instrument, in particular for manufacturing a flexible shaft (1) according to one of the claims 1 to 11, comprising the steps of: primary shaping (SI) of a shaft structure (2) having a distal end (3) and a proximal end (4) ; and supporting (S2) the shaft structure (2) by at least one strengthening member (5) for bearing axial and / or torque loads applied on the shaft structure (2) , wherein the at least one strengthening member (5) extends between the proximal end (4) and the distal end (3) .

14. Method according to claim 13, c h a r a c t e r i z e d i n t h a t2023P00167 LUKARL STORZ SE & Co. KG-36- the step of primary shaping (SI) comprises an extruding of the shaft structure (2) , whereir the at least one strength- ening member (5) is extruded in the same extrusion process of primary shaping or a wall of the shaft structure (2) has a through-opening for receiving the at least one strengthen- ing member (5) , and wherein the step of supporting (S2) com- prises a pushing of the at least one strengthening member (5) through the through-opening.

15. Method according to claim 13, c h a r a c t e r i z e d i n t h a t the step of primary shaping (SI) comprises an injection molding of at least two parts (2a, 2b) of the shaft structure (2) and wherein the method further comprises a step of coupling (S3) the at least two parts (2a, 2b) together for forming the shaft structure (2) , wherein the at least one strengthening member (5) is arranged at a contact area of the at least two parts (2a, 2b) .

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