Abstract
An endoscope having an endoscope head arranged on the distal end of the endoscope, preferably on the distal end portion of an actively curvable shaft portion. The endoscope has at least one optics device for imaging, and a working channel that extends in or on the endoscope along a longitudinal direction. The working channel has a working channel exit arranged on or in the endoscope head with a defined alignment relative to the optics device. The endoscope also has a pivot mechanism arranged between the distal shaft portion and the endoscope head. The pivot mechanism holds the endoscope head together with the working channel such that the endoscope head is foldable or bendable.
Claims
1. An endoscope having comprising: an endoscope shaft comprising a distal end portion; an endoscope head arranged on the distal end portion of the endoscope shaft, the endoscope head or a distal part of the endoscope head having or supporting at least one optics device for imaging; and a working channel that extends integrally within the endoscope in a longitudinal direction, the working channel having a working channel exit arranged or formed in the endoscope head or in the distal part of the endoscope head, wherein a pivot mechanism arranged between the distal shaft end portion of the endoscope shaft and the endoscope head or the distal part of the endoscope head and configured to hold the endoscope head or the distal part of the endoscope head in a foldable or bendable manner, for which the pivot mechanism has at least one segment which defines a disk or plate which is substantially round in plan view and substantially wedge-shaped in side view, said disk or plate having a flat circumferential portion when seen in side view, and which thickens towards a diametrically opposite circumferential portion to obtain a maximum plate thickness maximum at said opposite circumferential portion, which extends over a partial circumferential portion of the plate segment, resulting in a segment support or abutment surface which is oriented substantially perpendicular to the plate central axis and wherein, as seen in plan view, the working channel is formed to be decentral at least partially in said partial circumferential section.
2. The endoscope according to claim 1, wherein the pivot mechanism has a plurality of axially successive segments which are actively adjustable relative to one another in their angle by at least one actuating element, the plurality of axially successive segments being formed as the wedge-shaped plates having end faces oriented in a wedge-shaped manner relative to one another, as a result of which each plate is given a cylindrical envelope portion of minimum axial length and an opposite cylindrical envelope portion of maximum axial length, wherein two directly adjoining segments of the plurality of axially successive segments are aligned in each case relative to one another such that they are axially supported or rest upon each other at their respective cylindrical envelope portions of maximum axial length, resulting in a hinge or joint contact on the segment support or abutment surface.
3. The endoscope according to claim 2, wherein the cylindrical envelope portion of minimum axial length of each plate has an axial length of less than 2 mm.
4. The endoscope according to claim 1, wherein the pivot mechanism has at least two wires, Bowden cables or rods that are resiliently flexible, shear resistant, supported in the endoscope shaft, and distally articulated or fixed on the endoscope head or a distal part of the endoscope head, which is retained on the endoscope shaft only via the wires, Bowden cables or rods, the wires, Bowden cables or rods being provided and configured to be able to move only the endoscope head or the distal endoscope head part relative to the directly and axially proximally adjoining endoscope segment or endoscope head part, wherein the wires, Bowden cables or rods are pushed back and forth such that only the endoscope head or the distal part of the endoscope head is moved relative to the shaft.
5. The endoscope according to claim 1, wherein the endoscope further comprises a fine adjustment device separate from the pivot mechanism, the fine adjustment device allowing a more precise alignment of the working channel exit.
6. The endoscope according to claim 5, wherein the fine adjustment device is a hydraulically actuated actuator to which a pressure can be applied via a hose to bring about an inclination of the endoscope head.
7. The endoscope according to claim 6, wherein the fine adjustment device is biased by a spring element into a maximum tilted position of less than 15° with respect to a longitudinal axis of the endoscope and is transferrable against its biasing direction into a prograde alignment by: a solenoid supplied with electrical current, or (b) a pull wire fixed on the endoscope head and to which a tensile force is applied.
8. The endoscope according to claim 5, wherein the fine adjustment device has at least two wedge rings that rest against and slide on each other and are concentrically rotatable relative to one another.
9. The endoscope according to claim 5, wherein the fine adjustment has a piezo-based flexural transducer to which a voltage can be applied via an electrical line.
10. The endoscope according to claim 1, wherein the endoscope is a single-use combined gastroscope-duodenoscope.
11. The endoscope according to claim 1, wherein the distal end portion of the endoscope shaft is actively curvable.
12. The endoscope according to claim 4, wherein the wires, Bowden cables or rods are pushed back and forth selectively as well as independently of one another.
13. The endoscope according to claim 4, wherein the wires, Bowden cables or rods are pushed back and forth such that only the endoscope head or the distal part of the endoscope head is pivoted relative to the shaft.
Description
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0036] FIG. 1A is an illustration of a general endoscope design as is common in prior art;
[0037] FIG. 1B is an illustration for illustrating a field of application of an endoscope having a pivot mechanism of the invention according to a first aspect of the invention;
[0038] FIG. 2A is an illustration of a first embodiment of the pivot mechanism of the invention according to FIG. 1B in a front view;
[0039] FIG. 2B is an illustration of the first embodiment of the pivot mechanism of the invention according to FIG. 1B in a side view;
[0040] FIG. 3A is a perspective illustration of a pivot mechanism of the invention in a prograde alignment according to a second aspect of the invention;
[0041] FIG. 3B is a perspective illustration of the pivot mechanism of the invention according to FIG. 3A in an alignment pivoted by about 45°;
[0042] FIG. 4 is a perspective illustration of a fine adjustment or fine angular adjustment according to a third aspect of the invention;
[0043] FIG. 5A is a perspective illustration of a fine adjustment or fine angular adjustment according to a preferred modification;
[0044] FIG. 5B is a side view of the fine adjustment or fine angular adjustment according to FIG. 5A;
[0045] FIG. 6A is a side view illustration of a fine adjustment or fine angular adjustment according to a further modification in a prograde alignment;
[0046] FIG. 6B is a side view of the fine adjustment or fine angular adjustment according to FIG. 6A in an angled alignment;
[0047] FIG. 7A is a side view illustration of a fine adjustment or fine angular adjustment according to a further modification in a prograde alignment;
[0048] FIG. 7B is a side view of the fine adjustment or fine angular adjustment according to FIG. 7A in an angled alignment;
[0049] FIG. 8A is a side view illustration of a fine adjustment or fine angular adjustment according to a further modification in a prograde alignment; and
[0050] FIG. 8B is a side view illustration of the fine adjustment or fine angular adjustment according to FIG. 8A in an angled alignment.
DETAILED DESCRIPTION
[0051] FIG. 1A shows a conventional prior art endoscope design and is used to explain some of the terms employed below. The endoscope 2 has a handle part or operating part G at its proximal end facing the user, by means of which the handling by the user takes place. Distally adjacent to the handle part G is an elongated main body of the endoscope 2, which can be divided in the direction from proximal to distal into a series of consecutive portions, each with a different functionality: a shear-resistant and passively resilient flexible shaft S, an actively curvable distal shaft portion 3 (also called deflecting portion) and a distal, usually rigid end cap also called endoscope head 4. The endoscope 2 shown in FIG. 1A is inserted into the duodenum D via the esophagus and the stomach M, so that the endoscope head 4 is located in the area in front of the major duodenal papilla.
[0052] FIG. 1B is used to explain a preferred field of application of an endoscope according to the invention comprising a pivot mechanism. In addition, FIG. 1B shows a first preferred embodiment of such a pivot mechanism in an angled state.
[0053] FIG. 1B schematically shows the major duodenal papilla (P), which is located in the posterior (dorsal) descending part (Pars descendens) of the duodenum (D) and is relatively difficult to access due to the tortuous geometry of this system. The available space in the area of the duodenum (D) is very limited, which makes interventions at the major duodenal papilla (P) impossible with conventional, prograde endoscopes, since an appropriate angling of the endoscope tip toward the interventional section would not leave enough distance to the lumen of the duodenum (D) for proper imaging. In addition, such angling would be accompanied by the risk of perforation in the region of the duodenum due to the high bending radius of conventional devices.
[0054] For this reason, the duodenoscopes initially mentioned are known to prior art, which have a fixed optics device looking sideways or backward as well as a correspondingly aligned 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 alignment of the optics device and of the working channel. This complicates the general navigation within the patient, on the one hand, and makes such endoscopes inflexible in their application possibilities, on the other hand. In other words, they are expensive specialized devices for a narrowly limited field of application.
[0055] A basic idea of the present invention is therefore to provide, in addition or as an alternative to a known deflecting, a pivot mechanism associated with the endoscope head for the endoscope head or an endoscope head part, by means of which the endoscope head (head part) together with the optics device arranged thereon and the working channel exit of the endoscope can be pivoted by at least 90° without requiring a large bending radius for this purpose. In particular, a finely adjustable pivoting movement should be made possible, for example, to facilitate intubation of the major duodenal papilla. At the same time, a multifunctional device is to be provided, with the aid of which the majority of common applications in the area of the gastrointestinal tract can be performed.
[0056] For this purpose, the endoscope 2 shown in FIG. 1B has a first exemplary embodiment of a pivot mechanism 10 according to the invention, which in the perspective illustration is tilted by 90° with respect to a prograde/straight looking orientation in order to perform an intervention on the major duodenal papilla P. At the distal end of the pivot mechanism 10, an endoscope head or at least a part 4 of the endoscope head is arranged, which comprises or forms various functional units such as an optics device 6; a lamp 8 and a working channel 14. For the sake of clarity, only the above-mentioned most necessary functional units are shown in FIG. 1B, but it should be understood that an endoscope head according to the invention may additionally have various other functional units known from prior art, such as cleaning nozzles for an objective of the optics device 6, suction channels, etc., in the area of the depicted part 4.
[0057] The pivot mechanism 10 shown in FIGS. 2A and 2B in a front and a side view, respectively, has a main body 12 with a number of segments 16 (16′, 16″, 16′″ and 16″″) arranged sequentially in the axial direction of the endoscope 2. It should be noted at this point that at least the distally last segment 16′ (or all further segments) can also be regarded as a proximal part of the endoscope head 4, since they differ in their design and function from the rest of the shaft and from the optional, proximally arranged deflecting (if present).
[0058] The individual segments 16 basically have a wedge-like shape, i.e. their distal and/or proximal end faces converge at an acute angle and meet (as seen in side view) in a wedge tip 18. Accordingly, the axial extension of the individual segments 16 is greatest in a (diametrically opposite) portion 20 facing away from the wedge tip 18.
[0059] As can be taken in particular from FIG. 2B, the two end faces in the region of maximum segment thickness are flattened (aligned substantially parallel to each other) over a pitch circle section which is small compared to the wedge section (between the tip and the maximum segment thickness), thus forming a support/abutment surface for supporting two adjoining segments in prograde shaft alignment.
[0060] Preferably, in the illustrated embodiment, the individual segments 16 are further circular cylindrical in shape to provide a circular cross-section along the entire endoscope 2. As can be clearly seen in FIG. 2B, the wedge tips 18 and the portions 20 facing away from them are in alignment in the upright/straight position of the pivot mechanism 10. As a result, the pivot mechanism 10 can be angled unidirectionally.
[0061] Furthermore, it can be clearly seen in FIG. 1B that the working channel formed in the segments 16 is designed to be decentral at least in part in the area of the segments of maximum segment thickness, i.e. as close as possible to that circumferential portion of the respective segment which is diametrically opposite the segment tip.
[0062] In the upright/prograde configuration of the pivot mechanism 10 shown in FIG. 2A, the portions 20 of maximum segment thickness facing away from the wedge tips 18 respectively adjoin one another and form support or abutment areas/surfaces 22 around which or at which the individual segments 16 can be tilted relative to one another. Due to the wedge shape of the segments 16, sawtooth-like open spaces are formed towards the wedge tips 18 in the main body 12 of the pivot mechanism 10 in the upright position as shown in FIG. 2. The segments 16, which can be tilted about the support or abutment areas 22, can thus be folded towards one another, reducing these open spaces, until the respective proximal and distal end faces of adjacent segments 16 abut one another in a maximally curved position, as shown in FIG. 1B. Due to the fact that the wedge tips 18 have a relatively small axial extension of less than 1 mm in this case, a position folded by 90° can be achieved with a comparatively small inner bending radius. The small inner bending radius has the advantage that the optics device 6 and the lamp 8 do not protrude far beyond the outer circumference of the endoscope in said folded position (see FIG. 1B).
[0063] In order to effect the bending or folding described above, Bowden cable channels (not shown in detail here) are provided in the segments 16, in which Bowden cables (also not shown here) are guided. These are configured to apply a tensile force to the most distally arranged segment 16′, thereby generating a torque in the support or abutment areas 22, which causes the pivot mechanism 10 to fold/get curved. Corresponding Bowden cable mechanisms and associated operating elements are sufficiently known in prior art and are not explained in more detail here.
[0064] Preferably, a flexible or elastic hose inserted into the working channel can be used as the pivot hinge, which connects the loosely disposed segments to one another in a pivotable manner. Alternatively, however, it is also possible to dispense with such a hose and instead put in wires in the hinge area of the segments which hold the hinges together axially, as indicated in FIG. 2A.
[0065] In the preferred embodiment shown, the pivot mechanism 10 also has a strap brake 24 that can be used to fix the position thereof. The strap brake 24 according to the embodiment shown in FIGS. 2A and 2B has a shear-resistant, resiliently flexible brake strap 26 that runs along the inner bending radius of the pivot mechanism 10 through the segments 16 in the area of their wedge tips 18. The brake strap 26 is fixed to the segment 16′ supporting the endoscope head 4 and arranged furthest distally. If the pivot mechanism 10 is angled/tilted by means of the Bowden cables, the brake strap 26 moves axially in the proximal direction and passes through a braking member 28 proximally adjacent to the pivot mechanism. The braking member 28 has a brake shoe 30, which is designed as a solid-state joint. In the illustrated example, the brake shoe 30 is realized in the form of an elastic protrusion integrally formed in the region of the braking member 28 and extending obliquely between the radial direction and the distal axial direction of the endoscope 2. The brake strap 26 extends between a free end portion of the brake shoe 30 and a wall portion 34 of the braking member 28. The brake shoe 30 is connected to an axially acting piezoelectric element 32 which, when a voltage is applied thereto, pulls the brake shoe 30 toward proximal into a substantially radial alignment and in this position clamps the brake strap 28 against the wall portion 34, thereby locking the pivot mechanism 10. When the piezoelectric element 32 is extended, the brake strap 28 is released and the pivot mechanism 10 can be moved.
[0066] FIGS. 3A and 3B illustrate a second preferred embodiment of a pivot mechanism 10. In this embodiment, a support disk 46 is preferably provided as a distal part of the endoscope head, having its distally facing surface provided with a functional support 4 (for receiving, for example, an optics device and an illumination unit as well as a working channel exit) of the endoscope head. The support disk 46 is connected via a number (here three) of push-resistant, resiliently flexible drive shafts 40 (wires/rods, which can be considered as the proximal part of the endoscope head) to an actively curvable portion 3 (deflecting) of the endoscope shaft or, if this is not present, to the endoscope shaft itself. The drive shafts are each articulated/fixed in a peripheral region of the support disk 46, on its proximally facing side. By controlling the feed of the individual drive shafts 40 or by adjusting their respective protrusion beyond the distal edge (distal end face) of the actively curvable portion 3 or of the endoscope shaft, different tilt positions of the support disk 46 with respect to the distal end face of the deflecting/endoscope shaft can be set, as can be seen in FIG. 3B. The use of three drive shafts 40 according to the illustrated preferred embodiment has the advantage of avoiding static overdeterminations. In the illustrated embodiment, the drive shafts 40 are designed with robotic control, i.e. they are operated by means of small motors (not shown) and by software control. An operation of the pivot mechanism or a control of the feed of the individual wires by means of manual control elements such as rotary knobs or similar handling elements can be implemented just as well. For the purpose of achieving a sealing between the actively curvable portion 3 or the endoscope shaft and the endoscope head part 4 or the support disk 46 in the maximum advanced position shown in FIG. 3B, an expandable covering 5, preferably made of polyurethane or silicone, a bellows or the like is provided.
[0067] In the example shown in FIGS. 3A and 3B, the working channel 14 is arranged radially outside the main body of the endoscope (outside the shaft S, the deflecting 3 and the endoscope head 4), i.e. as far out as possible with respect to the intended direction of pivoting. This offers the advantage that when the pivot mechanism 10 is angled, as shown in FIG. 3B, smaller folding or pivoting radii can be achieved with sufficiently large radii of curvature of the working channel (just like in the exemplary embodiment according to the first aspect of the invention described above), which in turn simplifies the process of pushing a minimally invasive tool through it.
[0068] Conventional endoscopes for interventions on the major duodenal papilla (so-called duodenoscopes) have an actively operable deflection lever (also called Albarran lever) arranged in the distal area of a working channel exit aligned in prograde manner, by means of which minimally invasive instruments, guide wires and the like advanced through the working channel can be selectively deflected, whereas the alignment of the optics device is fixed and usually cannot be changed.
[0069] The pivoting mechanisms 10 of the invention according to the exemplary embodiments described above make the aforementioned Albarran lever obsolete, since minimally invasive instruments, guide wires and the like together with the optics device can be deflected per se in a very small space by the alignment capability of the working channel exit. As explained above, it is advantageous if the working channel 14 is arranged on the outer side or radially on the outside between the shaft S and the covering 5 in the area of maximum segment thickness, so that it can be located in the outer radius of the bend when the pivot mechanism 10 is bent and thus has as little influence as possible on the maximum possible folding path. Depending on the selected embodiment of the pivot mechanism 10, however, an additional fine adjustment of the pivoting/bending can be advantageous, e.g. to intubate the major duodenal papilla in a targeted manner.
[0070] According to a further aspect of the invention, which may exist independently, a fine adjustment device (fine adjustment or fine angle adjustment) 52 may therefore be provided in addition to the aforementioned pivoting member 10, which is provided according to the preferred embodiment between the pivoting member 10 and the endoscope head 4. The following fine adjustments are each shown by way of example in the arrangement on a segment 16′ according to the first embodiment of the pivoting member shown in FIGS. 1, 2A and 2B. Of course, a combination with the other embodiments for a pivoting member is equally possible and envisaged.
[0071] FIG. 4 shows an embodiment of the invention comprising a fine adjustment 52. The fine adjustment shown has a disk-shaped or plate-shaped head support 54, which is biased by means of a magnetizable flexion spring 56 into a maximum tilted position (approx. 5°-10° relative to the prograde alignment). A solenoid 58 disposed proximal to the flexion spring 56 in a segment 16′ of the pivoting member 10 is connected to a base station (not shown) via a power supply 60. By varying the current flowing through the solenoid 58, the head support 54 can be pulled toward the solenoid 58 in opposition to the bias. Preferably, a separate fixation element (not shown) can be used to hold the finely adjusted alignment in order to avoid excessive coil heating.
[0072] FIGS. 5A and 5B show a further embodiment of the invention comprising a fine adjustment 52. In the further embodiment of the fine adjustment 52 shown, the head support 54 is connected to a segment 16′ of the pivoting member 10 via two wedge rings 62, 64 which can be rotated relative to each other about the central axis of the endoscope. In FIGS. 8A and 8B, the wedge rings 62, 64 are shown in an orientation symmetrical in cross-section, which causes the head support 4 to be positioned straight. If, for example, the distal wedge ring 62 is rotated relative to the proximal wedge ring 64, the distal end face of the distal wedge ring (and thus the head support 54) tilts relative to the longitudinal axis of the endoscope. In the example shown, the relative rotation is effected by means of a resiliently flexible, torsionally stiff drive shaft 66, the distal end region of which is provided with a pinion, not shown, which interacts with a ring gear on the distal wedge ring 62. The axial cohesion of the wedge rings 62, 64 can be achieved, for example, by means of a tension spring, spring U-bolt, ball-and-socket arrangement or comparable form-fit arrangements. Alternatively, the drive shaft 66 can be fixed to the distal wedge ring 62 in tensile-proof manner in order to pull the latter toward the proximal wedge ring 64. This embodiment has the advantage that a very good rigidity of the finely adjusted positioning can be achieved. The arrangement described above can also be doubled, i.e. at least four wedge rings can be provided which are alternately fixed or rotatable relative to one another and which can be rotated relative to one another by means of two drive shafts 66. Such an arrangement allows pivoting in all directions. The free interior space of the wedge rings 62, 64, which is freely visible in FIG. 8B, provides sufficient space for channels and lines.
[0073] FIGS. 6A and 6B show a further embodiment of the invention comprising a fine adjustment 52, in which the head support 54 is held in the prograde position by spring pretension. On the circumferential side in the region of the inner bending radius of the pivot mechanism 10, the head support 54 is pivotably arranged on the segment 16′. On an opposite peripheral portion, a hydraulic hose 68 extending in the axial direction of the endoscope is provided, which ends with its distal end below the head support 54. At said distal end of the hydraulic hose 68, a balloon or piston element 70 is arranged which, when pressurized, accomplishes a variable tilting of the head support 54. Such a system offers the advantage of good stiffness of the finely adjusted position.
[0074] In addition, a water-filled hydraulic hose 68 has the advantage of good biocompatibility, which minimizes risks to the patient in the event of a malfunction. In combination with the first embodiment of the pivot mechanism 10 (FIGS. 1, 2A and 2B) comprising wedge-shaped segments 16, the hydraulic hose 68 can be used as a tilt joint for the segments 16 at the same time and thus does not require additional space.
[0075] FIGS. 7A and 7B show a further embodiment of the invention comprising a fine adjustment 52, which functions similarly to the immediately aforementioned embodiment of the fine adjustment; here, however, the head support 54 is preloaded in its end position (e.g. inclined 5° to 10° relative to the longitudinal axis of the endoscope). A Bowden cable 72 arranged in the peripheral region of the outer bending radius of the pivot mechanism 10 is used to pull the head support 54 against the pretension in the direction toward the wedge-shaped segment 16′. Due to the Bowden cable 72, such a fine adjustment 52 also has good stiffness and no approval problems for the medical field, as the use of Bowden cables is proven in endoscopy. In combination with the first embodiment of the pivot mechanism 10 (FIGS. 1, 2A and 2B) comprising wedge-shaped segments 16, the Bowden cable 72 can also be used as a tilt joint for the segments 16 and thus does not require any additional space.
[0076] FIGS. 8A and 8B show a further embodiment of the invention with a fine adjustment 52. In this embodiment, a piezo-based flexural transducer 74 arranged in the area of the inner bending radius of the pivot mechanism is used as a joint connection between the pivot mechanism 10 (the segment 16′) and the head support 54. In the prograde normal position, the head support 54 is held in position by the piezoelectric element 76 of the piezo-based flexural transducer 74. By varying the voltage (transmitted via line 78), the bending of the piezo-based flexural transducer 74 and thus the tilt angle of the head supports 54 can be finely adjusted. This has the advantage that the piezo-based flexural transducer 74 does not require any power consumption when holding its position and consequently does not heat up. This design variant also advantageously manages without any spring pretension.
