Patent Description:
An endoscope is a device that allows for examining the inside of living organisms, but also technical cavities. An important part of an endoscope is the flexible insertion tube. The requirements for an insertion tube are high and diverse. On the one hand, it must be flexible so that it can be inserted into the human body. On the other hand, the insertion tube must have a certain stiffness. During the examination, the physician must be able to push and turn the insertion tube using the control body. For this, the insertion tube must be stiff (rigid) enough not to be kinked or twisted. Conventional insertion tubes therefore require a very complex design and high manufacturing costs in order to meet these requirements.

In order to meet all requirements, the insertion tube must have various properties. Three of the most important properties of an insertion tube are bending flexibility, torsional rigidity (torsional resistance) and dimensional stability (form/shape stability). On the one hand, it must be bendable in order to be inserted into the (e.g. human) body to be examined. On the other hand, the insertion tube must have a high torsional rigidity in order to be able to transmit the torque generated by the user by rotation of a control body on to the distal end. Furthermore, the insertion tube must not deform when it is bent or twisted.

The requirement that an insertion tube must possess the abovementioned properties at the same time is in itself a technical contradiction. An element is normally stiff and dimensionally stable if it has high torsional rigidity. However, if the element has high bending flexibility, then it does not have high torsional rigidity and is not dimensionally stable.

To meet the above requirement, developers have been trying for some time to construct the base portion of the insertion tube from multiple components. A known design of a base portion of the insertion tube can be seen in <FIG>.

In the known solution of <FIG>, three different components are assembled to achieve the relevant properties of the base portion of an insertion tube <NUM>, namely high flexibility, high torsional rigidity and high dimensional stability.

A plastic coating <NUM> is heated until the material on its inner side partially melts and enters into gaps in a metal mesh <NUM>. This combination provides the base portion of an insertion tube <NUM> with high torsional rigidity and high bending flexibility. However, dimensional stability is still lacking here. For this, two metal sheet spirals <NUM> and <NUM> arranged in opposite directions are used. These metal sheet spirals <NUM> and <NUM> ensure that the insertion tube is dimensionally stable. The combination described now provides the insertion tube <NUM> with the three necessary properties mentioned: namely, high flexibility, high torsional rigidity and high dimensional stability.

One disadvantage of this complex design is in economic terms. Three components are assembled together in a complex manufacturing process. Both the materials and the manufacturing process cause high manufacturing costs.

<CIT> discloses an endoscope that includes a long insertion portion sequentially provided with first and second bending portions and a flexible tube portion, from a distal end side; first and second tubular portions including first and second notch portions provided inside of the first and second bending portions, respectively; and a third tubular portion including a third notch portion provided inside of the flexible tube portion, wherein the first to third tubular portions are formed in one tubular member, the first notch portion is formed by first notches bendable in at least two directions, the second tubular portion includes third notches formed in a direction different from the two directions of second notches.

<CIT> discloses a method for producing an insertion tub of an endoscope from a tube element, wherein the insertion tube has a proximal, passive, flexible section and a distal, anglable section, wherein cuts are made in the proximal, passive, flexible section in order to permit a bending of the proximal, passive, flexible section. In this method, the cuts in the proximal, passive, flexible section are designed such that neighbouring cuts are unevenly spaced apart. The disclosure also relates to an endoscope having an insertion tube of this type.

<CIT> discloses an instrument that has a cylindrical element which is insertable through a catheter into a body cavity. The cylindrical element has a distal end having a radially expandable functional portion and a stable diameter, and a cylindrical guide portion, which is arranged proximal to the functional portion. The distal end is structured for the formation of the functional portion such that the functional portion includes a web forming an integral extension of the guide portion. The element is formed by a solid wire or a hollow wire and formed from a composite material with two components.

It is an object of the present disclosure to provide a method of manufacturing an insertion tube of an endoscope and an endoscope with an insertion tube, which are less complex and by which costs can be reduced.

This object is met by an endoscope with the features of claim <NUM>. A corresponding method is provided in claim <NUM>. Further examples thereof are detailed in the dependent claims.

The disclosure is directed to an endoscope having an insertion tube, wherein the insertion tube has a proximal passive flexible section and a distal bending section, cuts are provided in the proximal passive flexible section to allow for bending the proximal passive flexible section, adjacent cuts in the proximal passive flexible section are unequally spaced, the proximal passive flexible section has secondary cuts adjacent to main cuts, the secondary cuts being arranged closer in a longitudinal direction of the proximal passive flexible section to the adjacent main cuts on one side of the secondary cuts than to the adjacent main cuts on the other side of the secondary cuts, and the main cuts extend along the circumference of the proximal passive flexible section in an interrupted manner such that uncut bridges (stays) remain between main cut portions lying on a circumferential line, wherein the proximal passive flexible section has the main cuts, wherein at least within a subzone in the proximal passive flexible section the main cuts are unequally spaced from each other (unequally spaced apart from each other) in the longitudinal direction of the proximal passive flexible section.

In the insertion tube of the endoscope according to the disclosure, cuts are formed with unequal spacing. The spacing of cuts formed in the insertion tube is thus different from each other. The cuts may be formed perpendicular to the axis of the insertion tube. In the proximal passive flexible section, main cuts are provided. At least within a subzone in the proximal passive flexible section, the main cuts are unequally spaced from each other in the longitudinal direction of the proximal passive flexible section.

This endoscope offers high flexibility in the shaping of bending angles in the proximal passive flexible section.

The main cuts may be spaced from each other (spaced apart from each other) in the longitudinal direction of the proximal passive flexible section with continuously increasing spacing. The main cuts may be spaced from each other in a distal direction of the proximal passive flexible section with continuously increasing spacing. Thus, the potential bending angle of the proximal passive flexible section decreases in the distal direction of the proximal passive flexible section and the bending (angulation, deflection) increases accordingly.

The main cuts may be spaced from each other in the longitudinal direction of the proximal passive flexible section with continuously decreasing spacing. The main cuts may be spaced from each other in the distal direction of the proximal passive flexible section with continuously decreasing spacing. Thus, the potential bending angle of the proximal passive flexible section increases in the distal direction of the proximal passive flexible section and the bending (angulation, deflection) decreases accordingly.

At least within a first subzone in the proximal passive flexible section, the main cuts are spaced from each other in the longitudinal direction of the proximal passive flexible section with continuously increasing spacing, and at least within a second subzone in the proximal passive flexible section, the main cuts are spaced from each other in the longitudinal direction of the proximal passive flexible section with continuously decreasing spacing. A proximal passive flexible section may be implemented in which a decreasing potential bending angle of the first subzone is combined with an increasing potential bending angle of the second subzone.

The first subzone and the second subzone may border (abut) on each other. A proximal passive flexible section may be implemented in which a decreasing potential bending angle of the first subzone and an increasing potential bending angle of the second subzone are combined directly/back-to-back. The change of the potential bending angle can be realized within a short longitudinal extent.

Between the first subzone and the second subzone, a third subzone may be arranged in which the main cuts are equally spaced from each other in the longitudinal direction of the proximal passive flexible section. The change of the potential bending angle may be realized via a deliberate smooth transition of a constant potential bending angle (in the third subzone).

The aspects of the present disclosure explained above may be suitably combined.

Hereinafter, the present disclosure is described in detail with reference to the drawings by means of examples.

Referring now to <FIG>, a first example of the present disclosure is described below.

First, <FIG> shows a schematic side view of an endoscope <NUM> in which the disclosure can be employed. As can be seen from <FIG>, such an endoscope <NUM> has an insertion tube <NUM> arranged on the distal side of a control body <NUM>. The control body <NUM> serves as the operating unit of the endoscope <NUM>. The control body <NUM> includes a handle unit <NUM>.

The insertion tube <NUM> is a cylindrical pipe-like or tube-like structure.

The insertion tube <NUM> is described in more detail below in the direction in which it is inserted in a patient. The insertion tube <NUM> is inserted with the distal end first/in front.

At the distal side, the insertion tube <NUM> has a distal bending section (angulation section, deflecting section) A. The bending section A can be bent laterally relative to the proximal part of the insertion tube <NUM> by means of one or more control wires (cable pull or cable pulls). The control wire (steering wire) or cable pull, hereinafter referred to only as control wire, is supported in the interior of the insertion tube <NUM> guided in an direction of extension of the insertion tube <NUM> at an inner circumferential surface of the insertion tube <NUM>.

The distal end of the control wire is anchored at the distal side of the bending section A. The proximal end of the control wire is connected to a control element (steering element) arranged in the control body <NUM>. This control element tensions the control wire to bring about a desired bending of the bending section A.

Proximally from the bending section A, the insertion tube <NUM> is configured as a flexible tube member forming a proximal passive flexible section <NUM>. When the insertion tube <NUM> is inserted, the flexible section <NUM> follows the bending section A.

In <FIG>, it is indicated that the flexible section <NUM> is configured along its longitudinal direction into zones of varying flexibility. For example, as viewed in the proximal direction, the flexible section <NUM> has a first zone B, a second zone C, and a third zone D. The first zone B forms a distal portion (distal region), the second zone C forms a middle portion (middle region, central portion), and the third zone D forms a proximal portion (proximal region).

The third zone D is not shown in the partial view of <FIG>.

To avoid kink bending between the bending section A and the first zone B, the first zone B is preferably provided with the highest flexibility among the zones of the flexible section <NUM>. Since the first zone B is provided with a very high degree of flexibility, there is no abrupt transition of the flexibility between the bending section A and the first zone B.

The second zone C has a lower flexibility than the first zone B. The third zone D in turn has a lower flexibility than the second zone C.

The insertion tube <NUM> according to the disclosure is formed of one piece. That is, at the transition from the bending section A to the flexible section <NUM>, there are not two elements that are joined together. Thus, the distal bending section A and the proximal passive flexible section <NUM> with the three zones B, C and D are formed of a single pipe or tube.

On the proximal side, the insertion tube <NUM> is fixed at the distal end of the control body <NUM>. The insertion tube <NUM> can be fixed at the control body <NUM>, for example, by a locking/fixing ring, a sealing ring or directly. The insertion tube <NUM> may for example be glued or screwed to the control body <NUM>. The control body <NUM> has a first control wheel (steering wheel) F as a first control element for controlling a control wire or cable pull, and a second control wheel G as a second control element for controlling a control wire or cable pull. The first control wheel F may, by pulling a control wire or cable pull, bend (angle, deflect) the bending section A in a first plane (e.g., towards and away from the viewer in <FIG>). The second control wheel G can, by pulling a control wire or cable pull, bend (angle, deflect) the bending section A in a second plane that is perpendicular to the first plane (e.g., up and down in <FIG>).

The bending section A can be bent, for example, by <NUM> - <NUM> degrees. This is sufficient for most applications. In a special form, the bending section A can even be bent by <NUM> degrees.

The insertion tube <NUM> according to the disclosure and its manufacture are described in more detail below.

The entire insertion tube <NUM> is formed of/from a single pipe element (pipe member) or tube element (tube member, tubular piece/element), hereinafter referred to simply as pipe element. The pipe element is a pipe (or tube) of preferably relatively hard material. A pipe made of stainless steel is particularly preferred. However, a pipe made of hard plastic can also be used. In principle, however, any material suitable for medical purposes can be used.

Cuts are provided in the pipe element by a laser cutting machine, as explained in more detail below. After providing the cuts, certain parts of the pipe element are bent, as explained in more detail below. The manufacture of the base body (main body) of the entire insertion tube <NUM> does not require any further process steps other than the providing of cuts and the bending. Thereafter, the base body of the insertion tube <NUM> may be provided with a control wire and surrounded (sheathed) with a cover element (sheath element).

The individual sections of the insertion tube <NUM> are described in more detail below.

The flexible section <NUM> forms the proximal part of the insertion tube <NUM> according to the disclosure. The flexible section <NUM> has the three zones B, C and D, each with a different flexibility.

<FIG> shows the proximal passive flexible section <NUM> for improved clarity as if the three zones B, C and D were of equal length to each other along the longitudinal direction of the insertion tube <NUM>. This is, of course, not the case. The middle zone C is longer than the transition portion B and the connecting portion D. Of the three zones B, C and D, the middle zone C is the longest in the proximal passive flexible section <NUM>. In other words, the actual proximal passive flexible section <NUM> is formed by the structure of the middle zone C. The bending properties, elasticity and torsional rigidity of the proximal passive flexible section <NUM> are implemented by the structure of the middle portion C.

Hereinafter, the structure of the middle portion C and thus of the actual proximal passive flexible section <NUM> is described in more detail with reference to <FIG>.

<FIG> shows a partial schematic side view of a part of a proximal passive flexible section of the insertion tube of a first example according to the disclosure.

<FIG> shows a partial perspective view of the part of the proximal passive flexible section of <FIG>.

The cut structure of the first example according to the disclosure can be seen from <FIG>.

In the manufacture of this cut structure, a pipe (or tube) <NUM> is used as raw material. The pipe <NUM> has an axis and a longitudinal extent. The pipe <NUM> is made of a sufficiently hard material. For example, stainless steel may be used. Plastic or a nickel-titanium alloy such as nitinol may also be used. The pipe <NUM> later forms the insertion tube according to the disclosure.

The pipe <NUM> has a shape (or form) that initially is not flexible. The pipe <NUM> has a high torsional rigidity and a high dimensional stability.

In this pipe <NUM>, main cuts <NUM> are formed, preferably by laser, on the circumference in circumferential direction at predetermined spacings (distances, intervals) H. The circumferential direction refers to a direction that runs perpendicular to the axis of the pipe <NUM>. Along the pipe <NUM>, the spacing H is the same in each case.

The main cuts <NUM> penetrate the thickness of the wall of the pipe <NUM>. The main cuts <NUM> extend in the circumferential direction of the pipe <NUM> over almost half a circumferential length (circumference). Thus, two circumferentially consecutive main cut portions 98A, 98B are formed per circumferential line. Between the respective main cut portions 98A, 98B there is a bridge (stay) <NUM> at which the material of the pipe <NUM> is not cut. Viewed in the longitudinal direction of the pipe <NUM>, the portions in front of and behind (proximal and distal to) the respective main cut <NUM> are connected to each other via the bridge <NUM>. Thus, at each circumferential line for the main cut <NUM> there are two bridges <NUM>. At each circumferential line for the main cut <NUM>, the two bridges <NUM> are arranged diametrically opposed. Viewed in the circumferential direction, a length of a main cut portion 98A, 98B plus a length of the bridge <NUM> corresponds to exactly <NUM>°. The lengths of the main cut portion 98A and the main cut portion 98B are equal to each other.

From main cut <NUM> to main cut <NUM>, along the longitudinal direction of the pipe <NUM>, the bridges are offset by <NUM>° with respect to each other, as can be seen from <FIG>.

Secondary cuts (auxiliary cuts, side cuts) <NUM> are formed proximally and distally of each bridge <NUM> in the longitudinal direction of the pipe <NUM>. The secondary cuts <NUM> run parallel to the main cut portions 98A, 98B. The length of the secondary cuts <NUM> in the circumferential direction is longer than the length of the bridge <NUM> in the circumferential direction. The lengths of the secondary cuts <NUM> are equal to each other.

In the longitudinal direction of the pipe <NUM>, the spacing (distance) N of each secondary cut <NUM> from its adjacent main cut portions 98A, 98B is smaller than the spacing (distance) H of the main cuts <NUM>. Thus, a proximal secondary cut <NUM> and a distal secondary cut <NUM> are associated with each main cut <NUM> including the two main cut portions 98A, 98B.

In the longitudinal direction of the pipe <NUM>, the spacing N of each secondary cut <NUM> from its adjacent main cut portions 98A, 98B is also smaller than the spacing (distance) M of each secondary cut <NUM> from its adjacent secondary cut <NUM> associated with the next main cut <NUM>, see <FIG>.

The main cuts <NUM> and secondary cuts <NUM> change the characteristic of the pipe <NUM>. The pipe <NUM> becomes flexible. The flexibility and other properties/characteristics of the pipe <NUM> strongly depend on, among other things, the structure of the cuts <NUM>, <NUM>. More specifically, the cut width, cut length and spacings of the pipe cuts (tube cuts), among others (in addition to the material), are important factors affecting the properties of the pipe <NUM>.

In the portion X (region X) there is the cut structure which is responsible for the emergence of the high flexibility of the pipe <NUM>.

The relationship between the deformation and the spacing between pipe cuts during bending is explained below.

A pipe (or tube) in its original form without cuts has a certain bending rigidity (bending resistance). As soon as this pipe is cut, the bending rigidity decreases according to the shape and number of cuts provided in the pipe. The graphical representation in <FIG> shows the relationship between the deformation and the spacing between pipe cuts when the pipe is bent.

<FIG> shows the results of a bending simulation of a pipe provided with cuts. The deformation of a pipe with cuts during a bending process is shown.

The dashed-dotted line with two points indicates the spacing of a cut to its adjacent cut.

The solid line indicates the deformation of the pipe during bending.

The ordinate and the abscissa each show length unit values (e.g. mm).

The following can be seen from <FIG>: the greater the spacing between the pipe cuts, the greater the bending rigidity (the lower the deformation). If the spacing between the pipe cuts becomes infinite, the pipe <NUM> reaches its original highest bending rigidity.

Since an insertion tube of an endoscope requires a low bending rigidity (and thus a high flexibility), a spacing between the pipe cuts must consequently be as small as possible.

According to the disclosure, the structure in the portion X is configured such that the cuts <NUM> and <NUM> are close together (small spacing N) and four spring-like segments F1, F2, F3 and F4 are formed. If the cut pipe <NUM> is now bent, the segments F1, F2, F3 and F4 are pulled apart and thus a spring-like counterforce is generated. When the pipe <NUM> is relieved of load after bending, the counterforce acts on the pipe <NUM> such that it regains its straight shape. Along the longitudinal direction of the pipe <NUM>, this structure of the portion X is arranged repeatedly offset by <NUM>° along the entire length of the proximal passive flexible section C of the pipe <NUM>. As a result, the pipe <NUM> is uniformly flexible in all directions.

<FIG> shows the portion X as an enlarged section. In the structure of a main cut <NUM>, made up of a first main cut portion 98A and a second main cut portion 98B, with the associated secondary cuts <NUM> in the portion X, the spacing N between the main cut portions 98A, 98B and the associated secondary cuts <NUM> should be as small as possible to provide a high degree of flexibility.

The torsional rigidity (torsional resistance) of a pipe is explained below.

<FIG> shows a relationship between the deformation and the spacing between pipe cuts during bending with respect to torsional rigidity. In other words, the graphical representation of <FIG> shows the relationship between the deformation and the spacing between pipe cuts when the tube is twisted.

<FIG> shows the results of a twisting simulation of a pipe provided with cuts. The deformation of a tube provided with cuts during a twisting process is shown.

The dashed line indicates the spacing of a cut to its adjacent cut.

The solid line indicates the deformation of the pipe during twisting.

The following can be seen from <FIG>: A pipe (or tube) has a certain torsional rigidity in its original form without cuts. As soon as this pipe is cut, the torsional rigidity decreases according to the shape and number of cuts. The greater the spacing between pipe cuts, the greater the torsional rigidity (and the smaller the deformation during rotation). If the spacing between pipe cuts becomes infinite, the pipe reaches its original highest torsional rigidity.

Since a high torsional rigidity is required for an insertion tube of an endoscope, the spacing between pipe cuts should consequently be as large as possible.

<FIG> shows, in a portion Y (region Y) in an enlarged section, the spacing (distance) M of each secondary cut <NUM> from its adjacent secondary cut <NUM> associated with the next main cut <NUM>.

The structure in the portion Y shows that the spacing M between adjacent secondary cuts <NUM> should be as large as possible in order to provide a high degree of torsional rigidity. The exact spacing M between adjacent secondary cuts <NUM> can be determined according to individual needs.

The process of achieving dimensional stability (form/shape stability) of the pipe <NUM> is explained below.

A hard pipe is inherently dimensionally stable. The structure of the portion Y is configured such that the pipe <NUM> maintains dimensional stability after a plurality of cuts <NUM>, <NUM> have been provided thereon.

In this case, the secondary cuts <NUM> are arranged spaced apart so far such that the portion Y is relatively long in the longitudinal direction of the pipe <NUM>. In other words, this results in a wide annular portion in the portion Y which is free of cuts.

The portion Y can be considered as a short pipe (or tube) and therefore has a high degree of dimensional stability. If the entire pipe <NUM> is bent, sections F1, F2, F3 and F4 will yield because portion Y has inherent stability.

The pipe <NUM> is thus flexible in bending and at the same time dimensionally stable.

The interaction of the portions X and Y is explained below.

The overall structure of the proximal passive flexible section C is a combination between the portions X and Y.

Each of these portions X and Y provides a particular property to the pipe <NUM>.

In the portion X, the main cuts <NUM> and secondary cuts <NUM> are arranged close to each other to achieve a high degree of flexibility.

In contrast, in the portion Y, the secondary cuts <NUM> are spaced further apart from each other to achieve a high degree of torsional rigidity.

This results in the following interactions between the portion X and the portion Y:
In the portion Y, the secondary cuts <NUM> are spaced far apart from each other. This portion Y is thus stable during both bending and twisting. During bending, the portion Y remains almost unchanged. The portion X, on the other hand, gives way and defines the flexibility of the entire pipe <NUM>. The effect of the portion Y to the flexibility of the pipe <NUM> is insignificant.

In the portion X, the main cuts <NUM> and secondary cuts <NUM> are arranged very close to each other.

In the example, the main cuts <NUM> and the secondary cuts <NUM> have a different cut width with respect to each other. The cut width refers to the width of the respective cut in the longitudinal direction of the pipe. When the main cuts <NUM> and the secondary cuts <NUM> are formed by laser, the cut width is set by the choice of the diameter of the emitted laser beam bundle.

The cut width of the secondary cuts <NUM> should be kept as small as possible. By means of a laser, a cut width of, for example, far less than <NUM> can be achieved. For example, the secondary cuts <NUM> can be formed with a cut width of <NUM>. The main cuts <NUM> may be formed, for example, with a cut width of <NUM>. These values of the cut width constitute examples only. The appropriate cut widths in each case can be determined by tests.

Preferably, the cut width of the main cuts <NUM> is greater than the cut width of the secondary cuts <NUM>. For example, the cut width of the main cuts <NUM> may be ten times the cut width of the secondary cuts <NUM>. Again, this value is merely an example. The appropriate factor in each case may be set as needed. The disclosure is not limited to these values.

In the case of a torsional load, the pipe <NUM> is subject to a torsional moment (torsional torque) Mt acting about the longitudinal axis of the pipe <NUM>. Due to the exertion of the torsional moment, imaginary (virtual) longitudinal lines L of the pipe <NUM> running parallel to the longitudinal axis deform helically (spirally), as shown in <FIG>. Since the spacing N of the main cuts <NUM> and secondary cuts <NUM> in the portion X is very small, the deformation of the portion X will be only slightly different from that of the portion Y. The torsional rigidity of the portion Y defines the torsional rigidity of the entire pipe <NUM>. The effect of the portion X to the torsional rigidity of pipe <NUM> is insignificant.

By forming cuts with different spacings from each other as explained above, both a high degree of flexibility and a high degree of torsional rigidity can be achieved in the proximal passive flexible section C of the pipe <NUM>.

Thus, the endoscope tube <NUM> according to the disclosure in the proximal passive flexible section C of the flexible section <NUM> is bendable laterally to its longitudinal axis with a high degree of flexibility and also with a high degree of torsional rigidity.

The individual zones B, C and D in the flexible section <NUM> differ in that the spacing H of the cuts <NUM> in the longitudinal direction and thus the density of the cuts <NUM> are different.

In the zone B, the spacing H of the cuts <NUM> is the smallest. Thus, in the zone B, the density of the cuts <NUM> is the highest.

In the zone C, the spacing H of the cuts <NUM> is greater than in the zone B. In the zone D, the spacing H of the cuts <NUM> is greater than in the zone C.

Thus, the flexibility and bendability in the zone B is higher than in the zone C. Further, the flexibility and the bendability in the zone C is higher than in the zone D. In other words, the flexibility and the bendability of the respective zones of the flexible section <NUM> decrease in the proximal direction.

The zone D is provided with a portion on the proximal side that is not provided with cuts. This portion forms a transition to the control body J.

Transition from the bending section A to the flexible section <NUM>.

The transition portion from the bending section A to the flexible section <NUM> is indicated as portion/region K in <FIG>. In this portion K, the bending section A ends. In other words, the first, i.e. most proximal, member of the bending section A is arranged distally of the portion K.

As shown in <FIG>, <FIG>, in this portion K, the wall surface of the pipe element is cut by a cut <NUM> with the shape of an inverted letter C. In other words, the cut <NUM> in the pipe element is cut with the shape of an incomplete circle. The circle of the cut <NUM> is not cut through at the distal side, as can be seen from <FIG>. The non-cut distal side of the cut <NUM> forms a hinge <NUM> for a flap (tab, clip) <NUM>. The flap <NUM> has a lower ear <NUM>, an upper ear <NUM> and a flap center piece <NUM>. The lower ear <NUM> borders on an upper side of the flap center piece <NUM>. The upper ear <NUM> borders on a lower side of the flap center piece <NUM>.

The flap <NUM> is formed as follows. The location of the cut <NUM> is determined. A hole <NUM> is cut in the center of the cut <NUM>. The cut <NUM> is formed by laser as shown in <FIG>. The flap center piece <NUM> is supported from the rear side, i.e., from the inner side of the pipe element, by a post (or piston). The lower ear <NUM> is bent inwards relative to the flap center piece <NUM> by <NUM> degrees. The bending line of the ear <NUM> relative to the flap center piece <NUM> runs parallel to the axis of the pipe element (in <FIG> and <FIG>, in the direction pointing to the left and to the right). The upper ear <NUM> is also bent inwards relative to the flap centerpiece <NUM> by <NUM> degrees. The bending line of the ear <NUM> relative to the flap center piece <NUM> also runs parallel to the axis of the pipe element. Thereafter, the flap center piece <NUM> is bent inwards by <NUM> degrees. The bending line of the flap center piece <NUM> relative to the pipe element runs in the perpendicular sectional plane to the axis of the pipe element (in <FIG> and <FIG>, in the upward and downward direction). In other words, the flap center piece <NUM> is bent inwards by <NUM> degrees at the hinge <NUM>. In particular, the flap center piece <NUM> is bent inwards so far until a distal side edge of the lower ear <NUM> and a distal side edge of the upper ear <NUM> abut the inner circumference of the pipe element, see <FIG>.

The flap <NUM> serves as a support for a guide spring <NUM>. In particular, the proximal surface of the flap center piece <NUM> forms a stop surface for the distal end of the guide spring <NUM>. The two ears <NUM>, <NUM> support the flap center piece <NUM> and absorb compressive forces acting from the guide spring <NUM> and transmit them to the inner circumferential surface of the pipe element.

The flap center piece <NUM> has the centric hole <NUM>. The hole <NUM> has a larger diameter than a control wire and a smaller diameter than the guide spring <NUM>. The control wire is guided in the flexible section <NUM> in the guide spring <NUM> and passes through the hole <NUM> and extends further into the bending section A.

In the portion K, flaps <NUM> are provided equal to the number of control wires used (four in the present example). The flaps <NUM> are evenly distributed in the circumferential direction of the pipe element.

The detailed structure of the bending section A is shown in <FIG>.

The bending section A has individual joint members (articulating members, hinge members) <NUM> arranged in the longitudinal direction of the bending section A. The individual joint members <NUM> are pivotable relative to each other. In <FIG>, three consecutively arranged joint members <NUM> are shown: a joint <NUM>, proximal to the joint <NUM> a joint <NUM>, and proximal to the joint <NUM> a joint <NUM>.

The joint members <NUM> are configured identically to each other with the exception of the most distal joint member <NUM> and the most proximal joint member <NUM>.

The structure of the respective joint member <NUM> is discussed below with reference to joint member <NUM>.

The joint member <NUM> is formed as a pipe segment (tube segment) of the pipe element by laser cutting. The joint member <NUM> has distal boundary lines <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> and proximal boundary lines <NUM>, <NUM>, <NUM>, and <NUM> at the circumference of the pipe element.

The individual distal boundary lines are made up of a circle-like shaped head line <NUM>, two neck lines <NUM>, two shoulder lines <NUM>, two arm lines <NUM>, and an arm end line <NUM>. More specifically, the distal side of the joint member <NUM> is formed as follows. The circle-like shaped head line <NUM> forms an incomplete circle, which merges into a neck line <NUM> at the proximal side on each side. To each of the two neck lines <NUM>, a shoulder line <NUM> connects, which extends approximately perpendicular to the axis of the pipe element. To each of the two shoulder lines <NUM>, an arm line <NUM> connects, which extends approximately parallel to the axis of the pipe element in the distal direction. The two distal ends of the arm lines <NUM> are joined by an arm end line <NUM>, which again extends perpendicular to the axis of the pipe element.

As a result, the joint member <NUM> has a main body <NUM> from which, toward the distal side, a first head <NUM>, a first arm <NUM>, a second head <NUM>, and a second arm <NUM> protrude each by <NUM> degrees along an imaginary circumferential line that extends perpendicular to the axis of the joint member <NUM>. Thus, the heads <NUM>, <NUM> extend in a first imaginary plane. The arms <NUM>, <NUM> extend in a second imaginary plane that is offset by <NUM> degrees from the first imaginary plane. The two heads <NUM>, <NUM> of the joint member <NUM> form a pivoting axis for the joint member <NUM> arranged distally thereof.

Each head <NUM> is formed on the distal side by a head line <NUM>. Between the head <NUM> and the main body <NUM>, a constriction is formed by the neck lines <NUM>. The respective head <NUM> projects further in the distal direction than the respective arm <NUM>.

The individual proximal boundary lines are made up of a curved foot line <NUM>, two bottom lines <NUM>, two straight foot lines <NUM>, and a waist line <NUM>. More specifically, the proximal side of the joint member <NUM> is formed as follows. The curved foot line <NUM> forms an incomplete circle that is open at the proximal side. At each of the open ends of the incomplete circle, the curved foot line <NUM> merges with the bottom line <NUM>, each of which extends approximately perpendicular to the axis of the pipe element.

Each of the two bottom lines <NUM> connects to a straight foot line <NUM>, which extends approximately parallel to the axis of the pipe element in the distal direction. The two distal ends of the straight foot lines <NUM> are joined by a waist line <NUM>, which again extends perpendicular to the axis of the pipe element.

As a result, the joint member <NUM> has two feet <NUM> at the proximal side of the main body <NUM>, which extend in the proximal direction. Each foot <NUM> has, in the direction of extension, a straight side at the straight foot line <NUM> and a curved side at the curved foot line <NUM>.

In the region between the two straight foot lines <NUM>, an arm of the proximally located joint member <NUM> is arranged slidably in the longitudinal direction. In the region between the two curved foot lines <NUM>, a head of the proximally located joint member <NUM> is held immovable in the longitudinal direction. At most, a slight movement due to a play between the inner circumference of the curved foot line and the outer circumference of the circle-like shaped head line is possible.

In the non-bent state of the bending section A, the waist line <NUM> is spaced apart from the arm end line <NUM> of the proximally located joint member <NUM>, as shown in <FIG>. The arm end line <NUM> and the waist line <NUM> of the proximally located joint member <NUM> are parallel to each other.

In the non-bent state of the bending section A, the bottom line <NUM> is spaced apart from the shoulder line <NUM> of the proximally located joint member <NUM>, as shown in <FIG>. The bottom line <NUM> and the shoulder line <NUM> of the proximally located joint member <NUM> may be parallel to each other or approximately parallel to each other, or may be slightly angled (tilted) with respect to each other, as shown in <FIG>. Between the bottom line <NUM> and the shoulder line <NUM> of the proximally located joint member <NUM>, not only a simple cut line was formed, but the material of the pipe element has been cut out as a four-sided piece.

A respective head <NUM> forms a coupling portion that is coupled to an adjacent joint member <NUM>. The feet <NUM> form a guide portion that engages an adjacent joint member <NUM> so as to allow for an axial movement of the joint members <NUM> relative to each other.

<FIG> shows a top view of the bending section A with the respective joint members <NUM>. In the top view, the heads <NUM> of the joint members <NUM> can be seen.

<FIG> shows a side view of the bending section A with the respective joint members <NUM>. In the side view, the feet <NUM> of the joint members <NUM> can be seen.

The most distal joint member <NUM> has no head and is shown in <FIG> and <FIG>.

The most proximal joint member <NUM> has no foot and is shown in <FIG>, <FIG> and <FIG>.

In the example, the bending section A can be bent in two bending directions (angulation directions, deflection directions), namely upward and downward in <FIG> (and <FIG>), wherein the respective heads <NUM> of the joint members <NUM> form bending axes of the joint members <NUM>. In other words, the bending section A in <FIG> is pivotable upward and downward. In the illustration of <FIG>, the bending section A is pivotable toward and away from the viewer.

As shown in <FIG>, the waist line <NUM> forms a hinge portion for a cable guide flap (cable guide tab) <NUM>. The cable guide flap <NUM> extends from the waist line <NUM>. For the cable guide flap <NUM>, a portion of material is taken that extends along the straight foot lines <NUM> to the arm end line <NUM> of the proximally located joint member <NUM>. The cable guide flap <NUM> is hinged (articulated) at the waist line <NUM> and is bent inward by <NUM> degrees. The cable guide flap <NUM> has a centric hole <NUM>. The hole <NUM> has a larger diameter than the control wire.

Each of the joint members <NUM> has the cable guide flaps <NUM> with the hole <NUM> such that the cable guide flaps <NUM> for a particular control wire are arranged consecutively in the longitudinal direction of the bending section A. The cable guide flaps <NUM> serve as guide protrusions on which a control wire is supported. Thus, the cable guide flaps <NUM> guide the control wire associated thereto through the bending section A.

The joint members <NUM> may be arranged at the bending section A such that their heads face in the proximal direction, as shown in <FIG>. Alternatively, the joint members <NUM> may be arranged at the bending section A such that their heads face in the distal direction, as indicated in <FIG>.

The distal end of the bending section A is shown in <FIG>. In <FIG>, the joint member <NUM> of the bending section A located furthest on the distal side can be seen. The distal side of the control wire <NUM> is anchored in this joint member <NUM> located furthest on the distal side. The control wire <NUM> extends from the control body <NUM> to the joint member <NUM> of the bending section A that is located furthest on the distal side.

The attachment of the control wire <NUM> is shown in detail in <FIG>.

The control wire <NUM> is attached to the control wheel G in the control body <NUM>. When the control wheel G is turned in a tensioning direction, the control wire <NUM> is tensioned. When the control wheel G is turned in the relieving direction opposite to the tensioning direction, the control wire <NUM> is relieved.

The control wire <NUM> extends from the control body <NUM> running in the insertion tube <NUM> to the joint member <NUM> and forms a first section <NUM>. This first section <NUM> of the control wire <NUM> runs at the inner circumference of the insertion tube <NUM>. This first section <NUM> of the control wire <NUM> is shown by reference sign <NUM> in <FIG>. A slit <NUM> is formed at the distal side of the joint member <NUM> (see <FIG>), the slit <NUM> penetrating the circumferential wall of the joint member <NUM> and extending in the longitudinal direction of the joint member <NUM>. Another similar slit <NUM> is provided at the distal side of the joint member <NUM> diametrically opposite the slit <NUM>.

The control wire <NUM> extends in the distal direction at the inner circumference of the joint member <NUM> and extends through the slit <NUM> to the outside, is wound in the circumferential direction of the joint member <NUM> up to the slit <NUM> at the outer circumference of the joint member <NUM>, extends through the slit <NUM> to the inside, and extends in the proximal direction at the inner circumference of the joint member <NUM> up to the control wheel G in the control body <NUM>.

The control wire <NUM> is thus divided into a first section <NUM> extending from the control wheel G in the control body <NUM> to the slit <NUM>, a second section <NUM> extending from the slit <NUM> at the outer circumference of the joint member <NUM> in the circumferential direction of the joint member <NUM> to the slit <NUM>, and a third section <NUM> extending from the slit <NUM> to the control wheel G in the control body <NUM>.

By turning the control wheel G in the tensioning direction, the control wire <NUM> is tensioned and thereby the bending section A is bent since the third portion <NUM> anchored at the joint member <NUM> is urged in the proximal direction. The third portion <NUM> of the control wire <NUM> thus forms a distal anchoring portion of the control wire <NUM>.

The insertion tube <NUM> according to the disclosure can be manufactured from a single pipe element, which is cut by laser. The pipe element is made of a relatively hard material, such as stainless steel or even suitable hard plastic. As a result of the cuts, the initially hard pipe element becomes flexible but retains its stiffness.

The cuts form the respective lateral incisions (cuts running perpendicular to the axis) <NUM>, <NUM> in the proximal passive flexible section <NUM>, the hole <NUM>, the cut <NUM> in the transition portion K, the hole <NUM>, the respective joint members <NUM> in the distal bending section A, and the slits <NUM>, <NUM>. This order is not to be construed as a limitation. For example, the slits <NUM>, <NUM> may be cut before the joint members <NUM>. Furthermore, the order of the cuts may also be reversed.

The flexibility and also the stiffness of the pipe element can be controlled by the shape, the arrangement and the size of the cuts.

The location of the respective cuts can be calculated beforehand and be predetermined. In a programmable laser cutting machine, the specified data for the respective cuts can be entered to automatically form the insertion tube <NUM>.

The individual joint members <NUM> are completely cut out and form physically separate bodies from each other, which are only form-fittingly connected (interlockingly connected, positively connected).

After laser cutting the pipe element, the flaps <NUM> and the cable guide flaps <NUM> are bent inwards. The raw body for the insertion tube <NUM> is thus completed.

The control wire <NUM> can now be inserted and attached in this raw body for the insertion tube <NUM>. The raw body for the insertion tube <NUM> can be attached to the control body <NUM>. Furthermore, a coating, preferably of metal for shielding the electrical control, surrounding the raw body for the insertion tube <NUM> can be fitted onto the raw body for the insertion tube <NUM> and an elastic cover (sheath) of plastic or rubber can be fitted onto the coating. The elastic cover of plastic or rubber can be subjected to thermal shrinkage.

Referring now to <FIG>, a second example of the present disclosure is described below.

<FIG> shows a partial schematic view of the proximal passive flexible section employed in the second example.

The proximal passive flexible section <NUM> constructed according to the principle illustrated in <FIG> may replace the proximal passive flexible section <NUM> of the first example. In other words, the control body <NUM> and the bending section A can be combined with the proximal passive flexible section <NUM> of the present second example.

As described above, the distal bending section A and the proximal passive flexible section <NUM> with the three zones B, C and D are formed from a single pipe or tube, see also <FIG>.

The zone B forms a transition portion B between the middle portion C and the bending section A. The zone C forms the middle portion C. The zone D forms a connecting portion D of the proximal passive flexible section <NUM> at the control body <NUM>. In other words, the entire insertion tube including the connecting portion D at the control body <NUM>, the middle portion C, the transition portion B between the middle portion C and the bending section A, and the bending section A is made of a single pipe element.

<FIG> shows the proximal passive flexible section <NUM> for better clarity as if the three zones B, C and D were of equal length to each other along the longitudinal direction of the insertion tube <NUM>. This is, of course, not the case. The middle portion C is longer than the transition portion B and the connecting portion D. The middle portion C is the longest in the proximal passive flexible section <NUM>. In other words, the actual proximal passive flexible section <NUM> is formed by the structure of the middle portion C. The bending properties, elasticity and torsional rigidity of the proximal passive flexible section <NUM> are implemented by the structure of the middle portion C.

The structure of the middle portion C of the proximal passive flexible section <NUM> is described in more detail below with reference to <FIG>.

The proximal passive flexible section <NUM> is made of the pipe element already described above. In the central portion C, a plurality of main cuts <NUM> are cut by laser cutting along the longitudinal direction of the pipe element. These main cuts <NUM> extend parallel to each other. The main cuts <NUM> extend perpendicular to the axis of the pipe element.

More specifically, the main cuts <NUM> extend along the circumference of the central portion C in an interrupted manner such that uncut bridges (stays) <NUM> remain between main cut portions lying on a circumferential line. In the present example, four main cut portions are formed as viewed in the circumferential direction.

<FIG> shows these main cut portions in more detail. <FIG> shows a first sequence of main cut portions formed in the circumferential direction with reference numerals 990A, 990B and 990C. <FIG> further shows a second sequence of main cut portions formed in the circumferential direction with reference numerals 990A1 and 990B1. The first sequence of main cut portions with the reference signs 990A, 990B and 990C is adjacent in the longitudinal direction to the second sequence of main cut portions formed in the circumferential direction with the reference signs 990A1 and 990B1. The length of the main cut portions in the circumferential direction is always the same. That is, not only the length of the main cut portions in the circumferential direction of a particular sequence of main cut portions is equal to each other, but the length of the main cut portions in the circumferential direction of all sequences of main cut portions in the entire middle portion C is equal to each other.

In the first sequence of main cut portions shown in <FIG>, a first main cut portion 990A, a second main cut portion 990B, and a third main cut portion 990C are shown. A fourth main cut portion, which is not visible, is arranged on the side of the pipe element facing away from the viewer, behind the drawing plane. The first main cut portion 990A, the second main cut portion 990B, the third main cut portion 990C, and the fourth main cut portion not shown are formed consecutively in the circumferential direction of the pipe element. Thus, at this circumferential line, the pipe element is cut sectionally four times with the same length. A respective bridge <NUM> is left between an end of the first main cut portion 990A and a beginning of the second main cut portion 990B, an end of the second main cut portion 990B and a beginning of the third main cut portion 990C, an end of the third main cut portion 990C and a beginning of the fourth main cut portion not shown, and an end of the fourth main cut portion not shown and a beginning of the first main cut portion 990A. The pipe element is not cut in the region of the bridge <NUM>.

In the second sequence of main cut portions shown in <FIG>, a first main cut portion 990A1 and a second main cut portion 990B1 are shown. A third main cut portion and a fourth main cut portion that are not visible are arranged on the side of the pipe element facing away from the viewer, behind the drawing plane.

The main cut portions of the second sequence are offset relative to the main cut portions of the first sequence. In the adjacent second sequence, the region of the first sequence where the main cut portions 990A, 990B and 990C leave the respective bridge <NUM> corresponds to a region that forms the center of the main cut portions 990A1 and 990B1 as viewed in the circumferential direction of the pipe element. Thus, the bridges are positioned offset by <NUM> degrees from sequence to sequence of main cuts <NUM> in the longitudinal direction of the pipe element.

The cut width of all main cuts <NUM> in the pipe element is the same. The spacing of all sequences of main cuts <NUM> in the pipe element is the same.

In the longitudinal direction of the pipe element, a secondary cut <NUM> is provided adjacent to each bridge <NUM>, as shown in <FIG>.

A secondary cut <NUM> is formed adjacent to the bridge <NUM> on both sides in the longitudinal direction of the pipe element. The secondary cut <NUM> is shorter than the main cut <NUM>. The secondary cut <NUM> overlaps with the ends of the adjacent main cuts <NUM>.

All of the secondary cuts <NUM> have the same length relative to each other in the circumferential direction of the pipe element. All secondary cuts <NUM> are parallel to each other and also parallel to the main cuts <NUM>.

Adjacent to both sides in the longitudinal direction of the pipe element, a respective sequence of secondary cuts <NUM> each is associated with a sequence of main cuts <NUM>. In other words, each sequence of main cuts <NUM> has a proximal sequence of secondary cuts <NUM> and a distal sequence of secondary cuts <NUM>.

Thus, seen along the longitudinal direction of the pipe element, a sequence of main cuts <NUM> is followed by a distal sequence of secondary cuts <NUM>, which is again followed by a proximal sequence of secondary cuts <NUM> of the next sequence of main cuts <NUM>. Viewed along the longitudinal direction of the pipe element, a sequence of secondary cuts <NUM> has a further sequence of secondary cuts <NUM> as a neighbor on one side and a sequence of main cuts <NUM> as a neighbor on the other side.

The secondary cuts <NUM> are formed closer in the longitudinal direction of the pipe element to the nearest main cuts <NUM> than to the nearest secondary cuts <NUM>.

In other words, adjacent to the main cuts <NUM>, secondary cuts <NUM> are provided such that they are arranged closer to the adjacent main cuts <NUM> than to the adjacent secondary cuts <NUM>.

To illustrate this, <FIG> shows the secondary cuts <NUM> for the first sequence of main cut portions as secondary cuts 991a and the secondary cuts <NUM> for the second sequence of main cut portions as secondary cuts 991b. The secondary cuts 991a for the first sequence of main cut portions are arranged closer to the adjacent main cut portions 990A, 990B and 990C than to the adjacent secondary cuts 991b. Thus, adjacent cuts in the pipe element are unequally spaced.

The cut width of all secondary cuts <NUM> in the pipe element is the same. The cut width of the secondary cuts <NUM> is narrower than the cut width of the main cuts <NUM>.

As in the first example, the structure of the second example provides an insertion tube <NUM> with a very high degree of flexibility and at the same time a high degree of torsional rigidity.

In the first and second examples, in the flexible section C, the main cuts are equally spaced from each other.

In contrast, in the present third example, in the flexible section C, the main cuts are unequally spaced from each other. The other aspects are the same as in the previous examples.

<FIG> shows a partial schematic view of the proximal passive flexible section in a third example in two variants in comparison with the previous examples.

In particular, <FIG> shows a first variant <NUM> of the cut design in the flexible section C; a second variant <NUM> of the cut design in the flexible section C; and a third variant <NUM> of the cut design in the flexible section C.

In the second variant <NUM>, as in the first and second examples, the main cuts <NUM> are equally spaced from each other in the flexible section C for comparison purposes.

In the first variant <NUM> and in the third variant <NUM>, however, adjacent main cuts <NUM>, <NUM> in the flexible section C are not equally spaced from each other. <FIG> shows a subzone in the proximal passive flexible section C in each of the first variant <NUM> and the third variant <NUM>. In this subzone, the spacing between adjacent main cuts is unequal.

In the respective variants shown, the spacings (distances) between the adjacent main cuts are thus designed differently. In the respective upper section of <FIG>, a spacing between adjacent main cuts is marked by means of a circle. In the distal direction of the flexible section C, this spacing between adjacent main cuts increases in the first variant <NUM>; remains the same in the second variant <NUM>; and decreases in the third variant <NUM>.

The first variant <NUM> shows the case in which the spacings - measured in the direction of extension of the endoscope - between the adjacent main cuts <NUM> increase towards the distal side. The main cuts shown in the first variant <NUM> are grouped together using the reference sign <NUM>. Non-cut bridges (stays) <NUM> are present between main cut portions <NUM> lying on a circumferential line. Secondary cuts are shown with reference sign <NUM>. The secondary cuts are described in the previous examples. Express reference is made to the details explained therein.

A first main cut 2611A shown is spaced from the second main cut 2611B shown by a spacing that is smaller than a spacing between the second main cut 2611B shown and a third main cut 2611C shown. The spacing between the second main cut 2611B shown and the third main cut 2611C shown is in turn smaller than a spacing between the third main cut 2611C shown and a fourth main cut 2611D shown, and so on. In the distal direction, the spacing between the main cuts 2611A, 2611B, 2611C, 2611D, 2611E, and 2611F shown becomes larger and larger.

In the first variant <NUM>, the spacing between the main cuts may increase uniformly (continuously) towards the distal side.

For example, the increase in spacing may be such that the second main cut 2611B is spaced from the third main cut 2611C by a spacing H2 that is greater than a spacing H1 between the first main cut 2611A and the second main cut 2611B by a value y (difference); and the fourth main cut 2611D is spaced from the third main cut 2611C by a spacing H3 that is greater than the spacing H2 by the same value y.

In another example, the increase in spacing may be such that the second main cut 2611B is spaced from the third main cut 2611C by a spacing H2 that is greater than a spacing H1 between the first main cut 2611A and the second main cut 2611B by a value y; and the fourth main cut 2611D is spaced from the third main cut 2611C by a spacing H3 that is greater than the spacing H2 by y multiplied by a factor z (which is greater than <NUM>).

The increase in spacing can be embodied arbitrarily.

In the first variant <NUM>, the spacing between the main cuts may also increase unevenly (discontinuously) towards the distal side.

The third variant <NUM> shows the case in which the spacings - measured in the direction of extension of the endoscope - between the adjacent main cuts <NUM> decrease towards the distal side. The main cuts shown in the third variant <NUM> are grouped together using the reference sign <NUM>. Non-cut bridges <NUM> are present between main cut portions <NUM> lying on a circumferential line. Secondary cuts are shown with reference sign <NUM>. The secondary cuts are described in the previous examples. Express reference is made to the details explained therein.

A first main cut 2613A shown is spaced from the second main cut 2613B shown by a spacing that is greater than a spacing between the second main cut 2613B shown and a third main cut 2613C shown. The spacing between the second main cut 2613B shown and the third main cut 2613C shown is in turn greater than a spacing between the third main cut 2613C shown and a fourth main cut 2613D shown, and so on. In the distal direction, the spacing between the main cuts 2613A, 2613B, 2613C, 2613D, 2613E, and 2613F shown becomes smaller and smaller.

In the third variant <NUM>, the spacing between the main cuts may decrease uniformly (continuously) towards the distal side. However, in the third variant <NUM>, the spacing between the main cuts may also decrease towards the distal side unevenly (discontinuously). As in the first variant, the increase in spacing can be embodied arbitrarily.

Thus, in the first variant <NUM>, the main cuts <NUM> are spaced from each other in the longitudinal direction of the proximal passive flexible section C with continuously increasing spacing; and in the third variant <NUM>, the main cuts <NUM> are spaced from each other in the longitudinal direction of the proximal passive flexible section C with continuously decreasing spacing.

The first variant <NUM> and the third variant <NUM> may be combined as subzones in a proximal passive flexible section C such that, at least within a first subzone <NUM> in the proximal passive flexible section C, the main cuts <NUM> are spaced from each other in the longitudinal direction of the proximal passive flexible section C with continuously increasing spacing, and at least within a second subzone <NUM> in the proximal passive flexible section C, the main cuts <NUM> are spaced from each other in the longitudinal direction of the proximal passive flexible section C with continuously decreasing spacing.

The first subzone <NUM> and the second subzone <NUM> may border (abut) on each other.

In another example, a third subzone <NUM> may be present between the first subzone <NUM> and the second subzone <NUM>, the third subzone <NUM> with an equal spacing between the main cuts.

<FIG> shows a partial schematic view of the proximal passive flexible section in the third example in further variants.

In the examples of <FIG>, a decrease or increase of the spacings between the adjacent main cuts is shown. The disclosure is not limited thereto.

Adjacent main cuts may also have unequal spacing with respect to each other without the spacing between the adjacent main cuts increasing or decreasing in the direction of extension of the endoscope.

<FIG> shows on the left an example of a fourth variant as subzone <NUM>.

<FIG> shows on the right side an example of a fifth variant as subzone <NUM>.

In the two variants shown, the spacings between the adjacent main cuts are also designed differently. In <FIG>, a spacing between adjacent main cuts is marked by means of a circle.

The main cuts shown in the fourth variant <NUM> are grouped together using reference sign <NUM>. The main cuts in the fifth variant <NUM> are grouped together using the reference sign <NUM>. Non-cut bridges (without reference signs) are present between main cut portions lying on a circumferential line. Secondary cuts are shown without reference signs. The secondary cuts are described in the previous examples. Express reference is made to the details explained therein.

In the fourth variant <NUM>, a first main cut 2711A shown is spaced from the second main cut 2711B shown by a spacing that is greater than a spacing between the second main cut 2711B shown and a third main cut 2711C shown. The spacing between the second main cut 2711B shown and the third main cut 2711C shown is smaller than a spacing between the third main cut 2711C shown and a fourth main cut 2711D shown. The spacing between the third main cut 2711C shown and the fourth main cut 2711D shown is greater than a spacing between the fourth main cut 2711D shown and a fifth main cut 2711E shown. The spacing between the fourth main cut 2711D shown and a fifth main cut 2711E shown is approximately equal to a spacing between the fifth main cut 2711E shown and a sixth main cut 2711F shown. The spacing between the fifth main cut 2711E shown and the sixth main cut 2711F shown is smaller than a spacing between the sixth main cut 2711F shown and a seventh main cut <NUM> shown.

Thus, in the distal direction, there is a rather particular respective spacing between the main cuts 2711A, 2711B, 2711C, 2711D, 2711E, 2711F and <NUM> shown.

In the fifth variant <NUM>, also a particular respective spacing between the main cuts 2713A, 2713B, 2713C, 2713D, 2713E, 2713F and <NUM> shown is illustrated.

In another variant not shown, adjacent main cuts may each have completely arbitrary spacings from each other. A relatively short spacing can follow a relatively large spacing.

<FIG> and <FIG> each show a subzone in the proximal passive flexible section C. In this subzone, the spacing between adjacent main cuts is unequal. Bordering on this subzone, in the remaining part of the proximal passive flexible section C, the spacing between adjacent main cuts may be equal. Alternatively, in the entire proximal passive flexible section C, the spacing between adjacent main cuts may be unequal. Different ones of the possibilities shown may be suitably combined for designing unequal adjacent spacings between adjacent main cuts.

The third example thus shows an endoscope with an insertion tube <NUM>, the insertion tube <NUM> having a proximal passive flexible section C and a distal bending section A, cuts <NUM>, <NUM>; <NUM>, <NUM> being provided in the proximal passive flexible section C to allow for bending the proximal passive flexible section C, adjacent cuts <NUM>, <NUM>; <NUM>, <NUM> in the proximal passive flexible section C being unequally spaced, the proximal passive flexible section C having secondary cuts <NUM>; <NUM> adjacent to main cuts <NUM>; <NUM>, the secondary cuts <NUM>; <NUM> being arranged closer in the longitudinal direction of the proximal passive flexible section C to the adjacent main cuts <NUM>; <NUM> on one side of the secondary cuts <NUM>; <NUM> than to the adjacent main cuts <NUM>; <NUM> on the other side of the secondary cuts <NUM>; <NUM>, the main cuts <NUM>; <NUM> extending along the circumference of the proximal passive flexible section C in an interrupted manner such that uncut bridges (stays) <NUM>; <NUM> remain between main cut portions <NUM>; <NUM> lying on a circumferential line, and the proximal passive flexible section C including the main cuts <NUM>; <NUM>, wherein at least within a subzone in the proximal passive flexible section C, the main cuts <NUM>; <NUM> are unequally spaced from each other in the longitudinal direction of the proximal passive flexible section C.

Due to the varying spacing between adjacent main cuts, a proximal passive flexible section C can be designed in which a highly flexible bending (angulation, deflection) can be achieved.

A larger spacing between adjacent main cuts results in a smaller bending angle and a smaller angulation range (bending range, deflection range) in the proximal passive flexible section C. A smaller spacing between adjacent main cuts results in a larger bending angle and a larger angulation range in the proximal passive flexible section C.

A structure with an ever increasing spacing between adjacent main cuts results in an ever decreasing bending angle and an ever decreasing angulation range in the proximal passive flexible section C.

A structure with an ever decreasing spacing between adjacent main cuts results in an ever increasing bending angle and an ever increasing angulation range in the proximal passive flexible section C.

By combining small and large spacings between adjacent main cuts, a highly individual design of the bending angle and the articulation range in the proximal passive flexible section C in the direction of extension becomes possible.

Bending shapes (angulation shapes, deflection shapes) not previously used in practice can be achieved, which are adapted to even complex anatomical conditions.

Certain selected and precisely defined sections and subsections in the bending section of the endoscope can be assigned certain bending properties (bending curve, stiffness, etc.) in a highly targeted manner.

In the first and second examples, the flexible section <NUM> has a first zone B, a second zone C, and a third zone D with different flexibility when viewed in the proximal direction. The number of zones or portions with different flexibility is not limited. The flexible section <NUM> may also have more or less zones with different flexibility. The disclosure is also applicable to an insertion tube in which the flexible section <NUM> has a constant flexibility throughout.

In the first and second examples, the pipe element of the insertion tube <NUM> is formed of stainless steel. The disclosure is not limited thereto. The material of the insertion tube <NUM> may be any sufficiently stiff material, such as a stiff plastic. In another alternative, nitinol (a nickel-titanium alloy) may be employed as the pipe material. This material has, among other things, the property of so-called superelasticity, i.e. it can be elastically deformed over wide ranges without being bending permanently.

In the first and second examples, cuts are provided in the pipe element by a laser cutting machine. These cuts can be provided very precisely. Therefore, manufacturing by laser is preferred. However, in principle it is conceivable that these cuts can also be fabricated by other manufacturing methods such as sawing, wire sawing, etc..

In the first and second examples, the bending section A can be bent (angled, deflected) in two bending directions (angulation directions), namely upward and downward in <FIG> and <FIG>. In an alternative, the individual joint members <NUM> may be formed such that their heads <NUM> from joint member <NUM> to joint member <NUM> are offset rotated by <NUM> degrees about the axis of the bending section A (axis of the joint members <NUM>). In this alternative, the bending section A can be bent in four bending directions, namely up and down and towards and away from the viewer in <FIG> and <FIG>.

In the alternative, in which the bending section A can be bent in four bending directions, two control wires <NUM> can be used which extend in the insertion tube <NUM> offset by <NUM> degrees from each other. The joint member <NUM> is then provided with four distal slits which are also offset by <NUM> degrees from each other.

In the example, a respective joint member <NUM> is formed in the shape described. The disclosure is not limited to the shape of the joint member <NUM>. It is sufficient if joint members are cut in the bending section A that are coupled to each other and allow for a deflecting movement of the bending section A.

The proximal passive flexible section C constructed according to the principle illustrated in <FIG> may be applied in the first or second example. This means that the proximal passive flexible section C shown in <FIG> forms part of the single-piece pipe element for the entire insertion tube <NUM>. Thus, the pipe element for the entire insertion tube <NUM> including the proximal passive flexible section C is made of/from a pipe element by laser cutting.

Alternatively, the proximal passive flexible section C may be manufactured separately from the rest of the insertion tube <NUM> in the first or second example.

In the example of <FIG>, in the longitudinal direction of the pipe element, two secondary cuts are arranged adjacent to each bridge on both sides of the bridge. In an alternative, in the longitudinal direction of the pipe element, one secondary cut may be arranged adjacent to each bridge on one side of the bridge.

In the first example, the main cuts are provided such that two bridges remain between the main cut portions along the circumference of the pipe element.

In the second example, the main cuts are provided such that four bridges remain between the main cut portions along the circumference of the pipe element.

The disclosure is not limited thereto. Preferably, the number of bridges along the circumference of the pipe element between the main cut portions is at least two or more and may be any number.

In the first example, the cut width of the main cuts <NUM> is greater than the cut width of the secondary cuts <NUM>. Also in the second example, the cut width of the main cuts may be greater than the cut width of the secondary cuts. However, the principle of the disclosure is also applicable in the case where the cut width of the main cuts is equal to the cut width of the secondary cuts.

The disclosure can advantageously be employed in a duodenoscope, a gastroscope, a colonoscope or a similar endoscope. The principle of the disclosure can also be applied to any other type of endoscope.

Claim 1:
An endoscope with an insertion tube (<NUM>),
wherein the insertion tube (<NUM>) comprises a proximal passive flexible section (C) and a distal bending section (A),
cuts (<NUM>, <NUM>; <NUM>, <NUM>) are provided in the proximal passive flexible section (C) to allow for bending the proximal passive flexible section (C),
adjacent cuts (<NUM>, <NUM>; <NUM>, <NUM>) in the proximal passive flexible section (C) are unequally spaced,
the proximal passive flexible section (C) comprises secondary cuts (<NUM>; <NUM>) adjacent to main cuts (<NUM>; <NUM>), wherein the secondary cuts (<NUM>; <NUM>) are arranged closer (N) in a longitudinal direction of the proximal passive flexible section (C) to the adjacent main cuts (<NUM>; <NUM>) on one side of the secondary cuts (<NUM>; <NUM>) than to the adjacent main cuts (<NUM>; <NUM>) on the other side of the secondary cuts (<NUM>; <NUM>), and
the main cuts (<NUM>; <NUM>) extend along the circumference of the proximal passive flexible section (C) in an interrupted manner such that uncut bridges (<NUM>; <NUM>) remain between main cut portions (<NUM>; <NUM>) lying on a circumferential line,
wherein the proximal passive flexible section (C) comprises the main cuts (<NUM>; <NUM>), wherein at least within a subzone in the proximal passive flexible section (C) the main cuts (<NUM>; <NUM>) are unequally spaced from each other in the longitudinal direction of the proximal passive flexible section (C),
characterized in that
at least within a first subzone (<NUM>) in the proximal passive flexible section (C), the main cuts (<NUM>; <NUM>) are spaced from each other in the longitudinal direction of the proximal passive flexible section (C) with continuously increasing spacing, and
at least within a second subzone (<NUM>) in the proximal passive flexible section (C), the main cuts (<NUM>; <NUM>) are spaced from each other in the longitudinal direction of the proximal passive flexible section (C) with continuously decreasing spacing,
wherein
the first subzone (<NUM>) and the second subzone (<NUM>) border on each other, or
a third subzone (<NUM>) is arranged between the first subzone (<NUM>) and the second subzone (<NUM>), wherein the main cuts (<NUM>) are equally spaced from each other in the longitudinal direction of the proximal passive flexible section (C) in the third subzone (<NUM>).