ENDOSCOPE DEFLECTION USING A DISTAL FOLDING MECHANISM

Abstract

An endoscope with a folding mechanism for foldably or bendably holding an endoscopy head at the distal end of the endoscope, preferably an endoscope shaft, having a number of axially successive segments that are adjustable via an actuating element. The segments define at least one channel for the passage of minimally invasive surgical instruments, flushing media, supply lines and the like. The segments are in the form of wedge-shaped cylinder sections having end faces oriented relative to each other in a wedge-shaped manner. Each cylinder section receives a cylinder jacket portion having a minimum axial length and an opposite cylinder jacket portion having a maximum axial length. Two directly adjacent segments are mutually oriented such that they are axially supported on or axially abut the relevant cylinder jacket portions of maximum axial length, which results in hinge- or joint-contact occurring on the support or placement point.

Claims

1. An endoscope comprising a folding mechanism for foldable or bendable mounting of an endoscope head at a distal end of an endoscope shaft, the folding mechanism comprising: a plurality of axially successive segments which are actively adjustable in angle relative to each other via at least one actuating element and said segments defining at least one work channel in an axial direction for passage of minimally invasive surgical instruments, flushing media, or supply lines, the segments being wedge-shaped or wedge-like cylinder sections with front sides oriented or set against each other in a wedge-shaped manner, whereby each cylinder section obtains a cylinder jacket portion with minimum axial length and a cylinder jacket portion with maximum axial length, the segments comprising directly adjacent segments that are oriented relative to one another in such a way that the directly adjacent segments are axially supported or rest on each other at a support or rest site at a region of their respective cylinder jacket portions of maximum axial length, whereby a hinge or joint contact is created at the support or rest site.

2. The endoscope according to claim 1, wherein front sides of the segments comprise setting angles, said front sides extending in a wedge-shape, said segments and setting angles being matched to each other in such a way that in a maximum folded position of the folding mechanism, in which the directly adjacent segments abut each other, a folding angle of at least 80° is obtained.

3. The endoscope according to claim 1, wherein the segments are designed in their wedge shape such that in the maximum folded position of the folding mechanism, an inner radius of curvature of the folding mechanism is less than twice a diameter of the folding mechanism, said diameter being defined by the segments.

4. The endoscope according to claim 1, wherein, in a 90° folded position of the folding mechanism, the distal front side of the endoscope head protrudes less than 2 cm, beyond a lateral jacket surface of the folding mechanism in a prograde orientation.

5. The endoscope according to claim 1, wherein the cylinder jacket portion with minimum axial length of the segments has an axial length less than 2 mm, whereby it forms a wedge tip when viewed in a side view.

6. The endoscope according to claim 1, wherein at least one traction element channel is provided for an actuating element designed as a traction element for angular adjustment of the segments, said traction element channel extending in the axial direction and being offset radially inwards relative to the support or rest sites of the segments, in a direction towards the wedge tip, so that the traction element running in the traction element channel forms a lever arm relative to the support or rest sites of the segments, contracting the wedge tips when a tractive force is applied.

7. The endoscope according to claim 15, wherein the traction element channel comprises two traction element channels provided in respective cross-sectional regions of the segments opposite the wedge tips, between which a working channel for passage of minimally invasive surgical instruments is arranged.

8. The endoscope according to claim 7, wherein the working channel has an oval cross-section whose longest diameter runs in a folding direction of the folding mechanism.

9. The endoscope according to claim 1, wherein the working channel is arranged outside the folding mechanism in an area of an outer radius of its direction of curvature.

10. The endoscope according to claim 1, wherein at least one of the support or rest sites between two of the directly adjacent segments is formed as a film hinge.

11. The endoscope according to claim 1, wherein the wedge-shaped segments are recessed in alignment in the area of their wedge tip, so that a clear region and a rib-like structure is produced towards the inner radius of curvature of the folding mechanism.

12. (canceled)

13. (canceled)

14. The endoscope according to claim 7, wherein the two traction element channels are provided in the segments, such that one of the actuating element channels is arranged on each cross-sectional half of the segments, with a border between the segments running from portions with minimum axial length to portions with maximum axial length.

15. The endoscope according to claim 6, wherein the at least one traction element channel is arranged in a region opposite the wedge tips in a cross-section of the segments.

16. The endoscope according to claim 1, wherein the endoscope shaft has a distal deflection portion separate from the folding mechanism, the distal deflection portion being actively and independently bendable via a pair of separate actuating elements.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0032] FIG. 1 is an illustration for visualizing an application area of an endoscope with a folding mechanism according to the invention;

[0033] FIG. 2 is an illustration of a basic structure of a folding mechanism according to the invention in a completely upright position;

[0034] FIG. 3 is an illustration of the basic structure of the folding mechanism according to the invention in a first curved position;

[0035] FIG. 4 is an illustration of the basic structure of the folding mechanism according to the invention in a second curved position;

[0036] FIG. 5 is an illustration of the basic structure of the folding mechanism according to the invention in a position of maximum curvature; and

[0037] FIG. 6 is a side view of the folding mechanism according to the invention.

DETAILED DESCRIPTION

[0038] FIG. 1 serves to explain a preferred field of application of an endoscope according to the invention or a folding mechanism according to the invention.

[0039] As can be seen from FIG. 1, the major duodenal papilla (P) is located in the rearward (dorsal) descending part (pars descendens) of the duodenum (D) and relatively difficult to access due to the tortuous geometry of this system. The space available in the region of the duodenum (D) is very limited, which means that procedures on the major duodenal papilla (P) are not possible with common prograde endoscopes, since at an appropriate angle, the endoscope tip would no longer have sufficient distance to the lumen of the duodenum (D) for proper imaging in the direction of the procedure portion.

[0040] Due to this reason, the aforementioned duodenoscopes are known from the prior art, which have a fixed sideways or retrospective optical unit as well as a correspondingly oriented working channel in order to make optimum use of the available space. However, such duodenoscopes have the disadvantage that they are fixed in their lateral/retrograde orientation of the optical unit and the working channel. On the one hand, this makes general navigation within the patient difficult and on the other hand makes such endoscopes inflexible in their possible applications. In other words, they are expensive special devices for a narrowly limited field of application.

[0041] A basic idea of the present invention is therefore to provide a folding mechanism for an endoscope, via which the endoscope head, which carries the optics and the working channel outlet of the endoscope, can be jointly pivoted by at least 90° for this purpose without requiring a large bending radius.

[0042] FIG. 2 shows a first exemplary embodiment of a folding mechanism 10 according to the invention in a first prograde orientation. At the distal end of the folding mechanism, an endoscope head 4 (shown in FIG. 1) is arranged in the fully assembled endoscope 2, which has different functional units such as an optical unit 6; lighting means 8 and a working channel 14. For the sake of clarity, only the most necessary functional units mentioned above are shown in FIG. 1 and in the following text; of course, an endoscope head according to the invention can also have various other functional units known from the prior art, such as e.g. cleaning nozzles for an objective of the optical unit 6, suction channels, etc.

[0043] The shown folding mechanism has a base body 12 with a number of segments 16 (16′, 16″, 16′″ and 16″) arranged in succession in the axial direction of the endoscope. The individual segments 16 basically have a wedge-like shape, i.e. their distal and proximal front faces converge at an acute angle and meet in a wedge tip 18. Accordingly, the axial extension of the individual segments 16 is greatest in the portion 20 (diametrically opposite) facing away from the wedge tip 18. In the embodiment shown, the individual segments 16 also have a circular-cylinder sectional shape in order to achieve a circular cross-section of the entire endoscope 2. As can be clearly seen in FIG. 2, the wedge tips 18 and the portions 20 facing away from them are aligned in the upright/extended position of the folding mechanism 10. As a result, the folding mechanism 10 can be bent unidirectionally.

[0044] In the upright configuration of the folding mechanism 10 shown in FIG. 2, the portions 20 facing away from the wedge tips 18 are adjacent to each other and form support or rest sites 22, around which the individual segments 16 can be tilted relative to each other. Due to the wedge shape of the segments 16, the base body 12 of the folding mechanism 10 has sawtooth-like clearances towards the wedge tips 18 in the upright position shown in FIG. 2. The segments 16, which can be tilted around the support or rest sites 22, can therefore be folded towards each other as shown in FIGS. 3 and 4, while reducing these clearances, until the proximal and distal front faces of adjacent segments 16 abut each other in the maximum deflected position shown in FIG. 5. Since the wedge tips have a relatively small axial extension of less than 1 mm, the 90° folded position shown in FIG. 5 can be achieved with a comparatively small inner bending radius. The advantage of the small inner bending radius is that the optical unit 6 and the lighting means 8 do not protrude far beyond the outer circumference of the endoscope in this folded position.

[0045] In the configuration example of FIGS. 2 to 5, the distal and proximal front faces of the individual segments 16 are each set at 23° to each other, resulting in a maximum folding angle of slightly more than 90° for four segments.

[0046] In order to achieve the deflection or folding described above, in the segments 16 in the area facing away from the wedge tips 18, Bowden cable channels 24 are provided, in which Bowden cables are guided, which are not shown in FIGS. 2 to 5 but which are indicated in FIG. 6. These are offset by a small distance (here: 1 to 3 mm) with respect to the support or rest sites 22 in the direction towards the wedge tips 18 so that when a traction force is applied to the most distal segment 16′, a torque is generated in the support or rest sites 22 via the lever arm h (cf. FIG. 6), which is defined in this way, which causes the folding mechanism 10 to fold/deflect. Shifting the Bowden cable channels 24 to the side 10 of the segments facing away from the wedge tips 18 has the advantage that the region of the wedge tips 18 can be made thinner, which allows a smaller inner bending radius to be achieved.

[0047] In the preferred embodiment shown, the support or rest sites 22 are designed as film hinges between the segments. This has the advantage that the base body 12 can be manufactured in one piece from plastic, e.g. by injection molding. The support or rest sites 22, which are designed as articulated portions/film hinges, create a connection between the individual segments 16, so that dislocation and thus a malfunction of the folding mechanism 10 cannot occur. At the same time, the articulated portions 22, which are designed as film hinges, provide a relative pivoting of the segments 16 about a defined pivot axis.

[0048] Since the lever arm h shown in FIG. 6 is relatively short due to the design described above, relatively high traction forces may be required to fold the folding mechanism 10. This can be compensated by providing a corresponding force amplification at the operating handle of the Bowden cables, e.g. via a toggle lever or the like. As indicated in FIG. 6, the Bowden cable can be anchored to the distal front face of the most distal segment 16′ and can be supported with its sleeve on the proximal segment 16′″ to effectively transfer the traction force F to the folding mechanism 10.

[0049] As can be seen in FIGS. 2 to 5, the interior of each segment 16 is provided with several cavities. The successive segments each have aligned cavities, resulting in different channels in the axial direction of the folding mechanism 10.

[0050] For example, the working channel 14 runs between the two Bowden cable channels 24 in the areas 20 of the segments 16 facing away from the wedge tip 18. The reason for this is that the bending radius of the working channel 14 is kept as large as possible when the folding mechanism 10 is folded. While the smallest possible bending radius of the entire folding mechanism is desired in order to reduce the radial projection of the endoscope tip when folded, the largest possible bending radius is desired for the working channel 14 per se, so that minimally invasive surgical tools W can still be ‘pushed around the curve’ when the working channel 14 is folded.

[0051] The individual segments 16 further form an inner lumen 26, through which various other functional and supply channels of the endoscope 2 can be guided. Examples of these are flushing, suction and insufflation channels or electrical/electronic lines to supply the imaging unit (of an image sensor which is not shown) or the lighting means 8, which has to be led from the distal endoscope tip to a proximal base station.