NL2015179B1 - A set of lockable cylindrical elements and a steerable instrument comprising same. - Google Patents
A set of lockable cylindrical elements and a steerable instrument comprising same. Download PDFInfo
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- NL2015179B1 NL2015179B1 NL2015179A NL2015179A NL2015179B1 NL 2015179 B1 NL2015179 B1 NL 2015179B1 NL 2015179 A NL2015179 A NL 2015179A NL 2015179 A NL2015179 A NL 2015179A NL 2015179 B1 NL2015179 B1 NL 2015179B1
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- cylindrical element
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- HLXZNVUGXRDIFK-UHFFFAOYSA-N nickel titanium Chemical compound [Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ti].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni].[Ni] HLXZNVUGXRDIFK-UHFFFAOYSA-N 0.000 description 2
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
- F16B7/04—Clamping or clipping connections
- F16B7/0406—Clamping or clipping connections for rods or tubes being coaxial
- F16B7/0413—Clamping or clipping connections for rods or tubes being coaxial for tubes using the innerside thereof
- F16B7/042—Clamping or clipping connections for rods or tubes being coaxial for tubes using the innerside thereof with a locking element, e.g. pin, ball or pushbutton, engaging in a hole in the wall of at least one tube
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mechanical Pencils And Projecting And Retracting Systems Therefor, And Multi-System Writing Instruments (AREA)
- Mutual Connection Of Rods And Tubes (AREA)
- Quick-Acting Or Multi-Walled Pipe Joints (AREA)
- Endoscopes (AREA)
Abstract
A first cylindrical element (303; 303') and a second cylindrical element (305; 305') can be inserted into and locked to one another. The first cylindrical element (303; 303 ')has an opening (323) and a self-guiding mechanism (325) with a first outer edge with a longitudinally extending portion (325a), a longitudinally retracted portion (325c) and a spirally formed edge portion (325e). The second cylindrical element (305) has a first stopping element (317; 317') and a second stopping element (313; 313 '). The first stopping element (31 7; 317 ') allows a sliding movement along the spirally formed edge portion (325e) when the first and second cylindrical elements are inserted into one another until a locked condition is reached in which the first stopping element (317; 317') abuts against the first longitudinally retracted portion (325c) and the second stopping element (313; 313') is in a snap-fit connection with the first opening (323).
Description
A SET OF LOCKABLE CYLINDRICAL ELEMENTS AND A STEERABLE INSTRUMENT COMPRISING SAME
FIELD OF THE INVENTION
[ 01 ] The invention relates to a set of lockable cylindrical elements and a steerable instrument comprising same.
BACKGROUND OF THE INVENTION
[ 02 ] In many applications, two or more cylindrical elements are to be inserted into one another until they reach a locked condition into which the two cylindrical elements cannot, or only to a predetermined extent, longitudinally move with respect to one another. To that end, techniques like laser welding, welding, gluing, snap-fit connections, screw threads etc. can be used.
[ 03 ] A problem with snap-fit connections may be that the snap-fit connection comprises a resilient element in one cylindrical element like a lip that has to snap into an opening of an adjacent cylindrical element but where aligning of this resilient element and the opening is not easy.
SUMMARY OF THE INVENTION
[ 04 ] It is an objective of the invention to provide a solution to that problem.
[ 05 ] This is achieved by a set of cylindrical elements as defined in claim 1.
[ 06 ] Advantageous embodiments of the invention are claimed in dependent claims.
[ 07 ] So, in embodiments of the invention, all elements of the locking mechanism of two or more lockable cylindrical elements are made from parts of the cylindrical elements themselves. No extra additional components are necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[ 08 ] Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Embodiments of the invention will be described with reference to the figures of the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which: [ 09 ] Figure la shows a schematic perspective view of two cylindrical elements, one inserted into the other and fixed to one another by a locking mechanism.
[ 10 ] Figures lb and lc each show a different one of the two cylindrical elements of figure 1 a.
[ 11 ] Figures Id and le show different cross sections through the connected set of cylindrical elements of figure la.
[ 12 ] Figure If shows an embodiment in which three cylindrical elements are insertable into one another and connectable by means of the locking mechanism of the present invention.
[ 13 ] Figures lg-lj show alternative embodiments of cylindrical elements with a locking mechanism. 114 ] Figure 2a shows a side view of a non-limiting embodiment of a steerable invasive instrument with one steerable flexible zone in which the locking mechanism of figures la-le can be applied.
[ 15 ] Figure 2b shows a side view of a non-limiting embodiment of a steerable invasive instrument with two steerable flexible zones in which the locking mechanism of figures la-If can be applied.
[ 16 ] Figure 3a shows a longitudinal cross-sectional view of an exemplary embodiment of a steerable instrument of figure 2a and having one proximal and one distal flexible zone.
[17] Figure 3 b shows a perspective exploded view of the three cylindrical elements of the steerable instrument shown in figure 3 a.
[18] Figure 3c shows a top view of an unrolled version of an exemplary embodiment of the intermediate cylindrical element of the steerable instrument shown in figure 3b. The intermediate cylindrical element can be formed by rolling the unrolled version into a cylindrical configuration and attaching adjacent sides of the rolled-up configuration by any known attaching means such as by a welding technique.
[ 19 ] Figure 3d shows a perspective exploded view of three cylindrical elements of a steerable tube analogous to the exploded view of figure 3b, but with a varying diameter of the cylindrical elements.
[ 20 ] Figure 4a provides a detailed perspective view of a non-limiting embodiment of elongated tubular body of the steerable instrument of figure 2b.
[ 21 ] Figure 4b shows a longitudinal cross-sectional view of the elongated tubular body of the steerable instrument as shown in figure 4a.
[ 22 ] Figure 4c shows a longitudinal cross-sectional view of the elongated tubular body of the steerable instrument as shown in figure 4a, wherein the first proximal and first distal flexible zones are bent, thereby illustrating the operation of the steering arrangement.
[ 23 ] Figure 4d shows a longitudinal cross-sectional view of the elongated tubular body of the steerable instrument as shown in figure 4c, wherein additionally the second proximal and second distal flexible zones are bent, thereby further illustrating the operation of the steering arrangement.
[ 24 ] Figure 4e shows a perspective view of a part of the elongated tubular body as shown in figure 4a, wherein the outer cylindrical element partially has been removed to show an exemplary embodiment of the longitudinal steering elements that have been obtained after providing longitudinal slits to the wall of an intermediate cylindrical element that interconnects the first proximal flexible zone and the first distal flexible zone of the elongated tubular body.
[ 26 ] Figure 5 shows a schematic cross-section of a steerable tube with cylindrical elements as shown in figures 4a-4e, however, with a varying diameter.
DETAILED DESCRIPTION OF EMBODIMENTS
[ 26 ] Figure la shows set of cylindrical elements 301 which comprises a first cylindrical element 303 which is inserted into a second cylindrical element 305. They are connected by means of a locking mechanism, as will be explained in detail below. The first cylindrical element 303 has two end portions of which one is inserted into the second cylindrical element 305 and the other one 307 is extending from the second cylindrical element 305. The second cylindrical element 305 has an end portion 310 into which the first cylindrical element 303 is inserted and an other end portion 321 at its opposite end.
[ 27 ] First cylindrical element 303 and second cylindrical element 305 may have the same wall thickness but different wall thicknesses may be applied as well. The thickness may, e.g., be between 0.01 and 1 mm.
[ 28 ] The locking mechanism as shown in figure la comprises a stopping element 313 and a stopping element 317 attached to the second cylindrical element 305. As shown, here, the stopping element 313 is an inwardly bent lip cut out from the second cylindrical element 305 such as to leave an edge 315. The stopping element 317 is also an inwardly bent lip cut out from the second cylindrical element 305 such as to leave an edge 319. The inwardly bent lip 313 cooperates with an opening in the first cylindrical element 303 and, in the locked condition, abuts against an edge of that opening, as will be explained in detail below. In the locked condition, the inwardly bent lip 317 abuts against a portion of an outer edge of the first cylindrical element 303, as will also become apparent from the description below.
[ 29 ] First cylindrical element 303 comprises an opening 309 whereas the second cylindrical element 305 comprises a notch 311 in the side 310. In the locked condition of the first cylindrical element 303 and second cylindrical element 305 opening 309 and notch 311 are aligned such as to visually support an operator who inserts the first cylindrical element 303 in the second cylindrical element 305.
[ 30 ] Arrows Id and Ie, respectively, indicate the cross section views of figures Id and le, respectively.
[ 31 ] Figure lb shows the first cylindrical element 303 in more detail. It has an end portion 308 opposite to end portion 307. The end portion 308 has a self-guiding mechanism 325 comprising an outer edge with a longitudinally extending portion 325a as seen from the end portion 307, at least one longitudinally retracted portion 325c and at least one spirally formed edge portion 325e, 325f. Moreover, the end portion 308 has a first opening 323 defined by opening edges 323a, 323b, 323c, and 323d. Opening edge 323a is located most close to the outer edge of end portion 308.
[ 32 ] Preferably, longitudinally extending portion 325a is longitudinally aligned with opening 323. Also, preferably, first cylindrical element opening 323 is located at a first cylindrical element opening position and longitudinally retracted portion 325c is located at a tangentially rotated position relative to said first cylindrical element opening position.
[ 33 ] First cylindrical element 303 may have a second opening 331 defined by edges 331a-331d and located opposite to opening 323 as shown in figure le.
[ 34 ] The self-guiding mechanism 325 may have a second longitudinally extending portion 325b opposite to longitudinally extending portion 325a, and a second longitudinally retracted portion 325d, which is visible in the cross section view of figure le and located opposite to longitudinally retracted portion 325c.
[ 35 ] Figure lc shows an enlarged view of the second cylindrical element 305. All features shown in figure lc have already been explained with reference to figure la.
[ 38 ] Figure Id shows a cross section view of the first cylindrical element 303 and second cylindrical element 305 in the locked condition in the direction of arrows Id, or, stated otherwise, in an upside direction when they are cut into half in a horizontal plane when arranged as shown in figure la.
[ 37 ] As one can see in figure 1 d, inwardly bent lip 313 has an edge portion 313a arranged such as to face towards end portion 321. In the locked condition, inwardly bent lip 313 of second cylindrical element 305 is arranged inside opening 323 of the first cylindrical element 303 such that they form a snap-fit connection where edge portion 313a of inwardly bent lip 313 abuts against opening edge 323a. To have a solid abutment, it is preferred that edge portion 313a is bent inwardly to such an extent that it completely abuts against opening edge 323a. However, an abutment of between 50% and 100% may be sufficient.
[ 38 ] Inwardly bent lip 317 has an edge portion 317a arranged such as to face away from end portion 321. In the locked condition, edge portion 317a of inwardly bent lip 317 of second cylindrical element 305 abuts against longitudinally retracted portion 325c. To have a solid abutment, it is preferred that edge portion 317a is bent inwardly to such an extent that it completely abuts against longitudinally retracted portion 325c.
[ 39 ] So, in the locked condition first cylindrical element 303 cannot be inserted any further into second cylindrical element 305 because it is blocked from further insertion by inwardly bent lip 317. At the same time, the first cylindrical element 303 cannot be retracted anymore from the second cylindrical element 305 because such a movement is blocked by inwardly bent lip 313.
[ 40 ] Ideally, when edge portion 317a of inwardly bent lip 317 abuts against longitudinally retracted portion 325c, edge portion 313a of inwardly bent lip 313 abuts against opening edge 323a, such that first cylindrical element 303 cannot or hardly cannot move relative to second cylindrical element 305 in the longitudinal direction anymore. The play is preferably less than 0.1 mm. However, there may be applications allowing a larger play, e.g. less than 0.5 mm, and preferably less than 0.3 mm. However, depending on the application even more play can be accepted.
[ 41 ] In an embodiment, second cylindrical element 305 comprises an inwardly bent lip 327 with an edge portion 327a facing away from end portion 321. Then, first cylindrical element 303 has a longitudinally retracted portion 325d which, in the locked condition abuts against edge portion 327a. Again, to have a solid abutment, it is preferred that edge portion 313a is bent inwardly to such an extent that it completely abuts against longitudinally retracted portion 325d. However, a lower percentage of abutment may be applied instead.
[ 42 ] The function of the at least one spirally formed edge portion 325e is as follows. As one may see from figure 1 d, in the locked condition, longitudinally extending portion 325a is arranged closer to end portion 321 of second cylindrical element 305 than longitudinally retracted edge portion 325c (and 325d). Spirally formed edge portion 325e is arranged for the following function. When first cylindrical element 303 is inserted into second cylindrical element 305, it is difficult to do so such that inwardly bent lip 313 is directly aligned with opening 323 and inwardly bent lip 317 and 327, respectively, is directly aligned with longitudinally retracted portion 325c and 325d, respectively. However, if there is a mismatch in the tangential direction, inwardly bent lip 317 or 327, respectively, will slide along spirally formed edge portion 325e or 325f, respectively, such that first cylindrical element 303 and second cylindrical element 305 will rotate relative to one another to such an extent that inwardly bent lip 313 will move towards alignment with opening 323 to make a snap-fit connection, and inwardly bent lip 317 and 327, respectively, will move towards alignment with and abutment against longitudinally retracted portion 325c and 325d, respectively.
[ 43 ] It is observed that, in the embodiment of the figures, the longitudinally extending portion 325a has a tapered form. However, any other suitable form may be applied. It may have a rounded form. Also, the spirally formed edge portion 325e, 325f may have any suitable form, as long as it forces first cylindrical element 303 and second cylindrical element 305 to rotate relative to one another when first cylindrical element 303 is inserted into second cylindrical element 305 and spirally formed edge portion 325e, 325f slides against inwardly bent lip 317, 327. Some alternative embodiments will be explained with reference to figures lg-lj, hereinafter.
[ 44 ] Figure le shows a cross section view of first cylindrical element 303 and second cylindrical element 305 when inserted into one another and being in the locked condition, as indicated by arrows Ie in figure la. It shows that first cylindrical element 303 may have a second opening 331 as defined by opening edges 33 la to 33 Id. Second cylindrical element 305 may have an extra inwardly bound lip 329 arranged to make a snap-fit connection with opening 331 in the locked condition. In that locked condition, an edge 329a of inwardly bound lip 329 abuts against edge portion 331a of opening 331. Again, in the locked condition, any play between edge 329a and opening edge 331a is, preferably kept to a minimum, e g. less than 0.1 mm. However, there may be applications allowing a larger play, e.g. less than 0.5 mm, and preferably less than 0.3 mm.
[ 45 ] With reference to figures la to le, an embodiment has been explained in which first cylindrical element 303 can be inserted into second cylindrical element 305 until they are in the locked condition. However, in another embodiment, first cylindrical element may have a larger diameter than second cylindrical element such that it can be shifted over second cylindrical element 305 until the locked condition. In this latter embodiment, first cylindrical element may have the same design as the one shown in figures la to le. However, then, lips 313 and 317 of second cylindrical element 305 should be bent outwardly instead of inwardly, as will become apparent from figure If where such lips have been indicated with reference numbers 313’ and 317’.
[ 46 ] Figure If shows how the present invention can also be applied when three cylindrical elements ‘303’, 305’, 341 are to be inserted into and locked to one another. First cylindrical element 303’ is similarly designed as first cylindrical element 303 of figures la to le. Second cylindrical element 305’ now has a smaller diameter than first cylindrical element 303’ such that first cylindrical element 303’ can be shifted over second cylindrical element 305’ until they arrive at a locked condition. Second cylindrical element 305’ has a larger diameter than third cylindrical element 341 such that it can be shifted over third cylindrical element 341 until they are in a locked condition too. To that end, second cylindrical element 305 is provided with further locking means at its end portion 321 ’ for locking second cylindrical element 305’ to third cylindrical element 341.
[ 47 ] In the locked condition between first cylindrical element 303’ and second cylindrical element 305’ longitudinally retracted portion 325c abuts against outwardly bent lip 317’ such that first cylindrical element 303’ cannot be shifted any further over second cylindrical element 305’. In that locked condition, opening edge 323a abuts against outwardly bent lip 313a. The same observations apply as to the play of this locked condition as in the embodiment explained with reference to figures 1 a to 1 e.
[ 48 ] Apart from outwardly bent lips 313’, 317’, at end portion 321’, second cylindrical element 305’ is also provided with a self-guiding mechanism 335 designed in the same way as self-guiding mechanism 325 of first cylindrical element 303’. To that end, it has an outer edge with a longitudinally extending portion 335a, at least one longitudinally retracted portion 335c and at least one spirally formed edge portion 335e. Moreover, the end portion 321 ’ has a first opening 333 defined by opening edges 333a, 333b, 333c, and 333d. Opening edge 333a is located most close to the outer edge of end portion 321 ’.
[ 49 ] Second cylindrical element 305’ may have a further opening located opposite to opening 333 like opening 331 in cylindrical element 303 shown in figure le. Also, self-guiding mechanism 335 may have a further longitudinally extending portion 335b opposite to longitudinally extending portion 335a.
[ 60 ] The locking mechanism as provided by opening 333 and self-guiding mechanism 335 of second cylindrical element 305’ is designed to cooperate with a locking mechanism of third cylindrical element 341 which, in the embodiment shown in figure If, comprises outwardly bent lips 337 and 339 at end portion 342. Outwardly bent lip 337 is designed for a snap-fit connection with opening 333 when second cylindrical element 305’ and third cylindrical element 341 are in a locked condition. It prevents second cylindrical element 305’ from being retractable from third cylindrical element 341 in said locked condition.
[ 51 ] In the locked condition between second cylindrical element 305’ and third cylindrical element 341, outwardly bent lip 339 abuts against longitudinally retracted portion 335c to prevent second cylindrical element 305’ from being further shiftable over third cylindrical element 341 in said locked condition.
[ 52 ] Spirally formed edge portion 335e has the same function as spirally formed edge portion 325e in first cylindrical element 303, 303’. I.e., when second cylindrical element 305’ is shifted over third cylindrical element 341, and lip 337 is not well aligned with opening 333, then, second cylindrical element 305’ and third cylindrical element 341 are forced to rotate relative to one another when spirally formed edge portion 335e slides along lip 339 such that lip 337 will snap into opening 333 and establish the locked condition.
[ 53 ] As to play in the longitudinal direction between second cylindrical element 305’ and third cylindrical element 341 in their locked condition, the same applies as has been observed for the play in the locked condition between first cylindrical element 303 and second cylindrical element 305.
[ 54 ] In a further embodiment, the locking mechanism 333, 335 is not applied at end portion 321 ’ of second cylindrical element 305’ but at end portion 342 of third cylindrical element 341. Then, second cylindrical element 305’ is provided with two inwardly bent lips like inwardly bent lips 313 and 317 of second cylindrical element 305 and which are designed such as to cooperate with said locking mechanism 333, 335 at third cylindrical element 341.
[ 55 ] In a still further embodiment three cylindrical elements can be locked to one another by starting from first cylindrical element 303 and second cylindrical element 305 of figures la to le. Then, third cylindrical element 341 has a larger diameter than second cylindrical element 305 such that second cylindrical element 305 can be inserted into third cylindrical element 341. Then, the locking mechanisms of second cylindrical element 305 and third cylindrical element 341 may have the features as shown in figure If with reference to elements 333, 335, 337 and 339 be it that, then, lips 337 and 339 should be bent inwardly. Alternatively, elements 335a to 335e can be applied at the end portion 342 of third cylindrical element 341 and lips 337 and 339 at the end portion 321 of second cylindrical element 305, where these lips 337, 339 are then bent outwardly.
[ 56 ] In the embodiments of figures la-lf, when inserting the cylindrical elements into one another, it may happen that longitudinally extending portion 325a first abuts lip 317, preventing further insertion. If so, further insertion towards the locking condition would only be possible by first manually rotating the cylindrical elements relative to one another. This is solved in the embodiments of figures lg-lj.
[ 57 ] Figures lg-lj show cylindrical elements 303, 305 with alternative locking mechanisms. In the embodiment of figure lg and lh, cylindrical element 303 still comprises opening 323 but has an amended self-guiding mechanism 325. I.e. longitudinally retracted portions 325c and 325d are shaped like a tapered tip instead of a straight edge like in the embodiments of figures la-lf. Moreover, the edges 317a and 327a, respectively, of lips 317 and 327, respectively, are also tapered. Preferably the tapered form of edges 317a and 327a, respectively, matches the tapered form of the longitudinally retracted portions 325c and 325d, respectively. In the embodiments of figures lg and lh, insertion of the cylindrical elements into one another until the locking condition will not be obstructed if longitudinally extending portion 325a first abuts lip 317 because it will then slide along tapered edge 317a and force a rotating movement of the cylindrical elements relative to one another.
[ 58 ] It is observed that in this embodiment of figures lg and lh, the tapered forms need not necessarily have sharp edged tips. The tips may have rounded shapes instead.
[ 59 ] The alternative embodiment of figures 1 i and lj has the same tapered longitudinally retracted portions 325c and 325d as in figures lg and lh. However, longitudinally retracted portions 325c and 325d at opposing sides of cylindrical element 303 are longitudinally shifted relative to one another. Likewise, opposing lips 317 and 327 in cylindrical element 305 are longitudinally shifted such that, in the locking condition, longitudinally retracted portions 325c and 325d, respectively, still match tapered edges 317a and 327a, respectively, of lips 317 and 327. The embodiment of figures li and lj ensure that the cylindrical elements 303 and 305 can only be locked in one single correct circumferential orientation. I.e., in the embodiments of figures la-lh two cylindrical elements can also be locked in a 180° rotated orientation (which would still be correct of such rotated orientations would be symmetric).
[ 60 ] It is observed that such longitudinally shifted lips 317, 327 and longitudinally shifted longitudinally retracted portions 325c, 325d may be applied in the embodiments of figures la-lf without tapered lips 317, 327 as well.
[ 61 ] It will be evident that the locking mechanism shown in figures lg-lj can be applied in any of the embodiments of figures la-lf and not just the ones shown in figures lg-lj.
[ 62 ] The locking mechanism of the present invention can advantageously be applied in steerable instruments, e.g., medical steerable instruments.
[ 63 ] Preferably, in all embodiments explained above, in the locking condition two or more locked cylindrical elements are not only prevented from being longitudinally shiftable relative to one another, but also from being rotatable relative to one another. Rotatable fixation is obtained by at least one of tangential abutment between lips 313, 329, 337 and corresponding openings 323,.., 333 and tangential abutment between lips 317, 327 and corresponding longitudinally retracted portions 325c, 325d, 335c, 335d [ 64 ] Figure 2a shows a side view of a non-limiting embodiment of a steerable invasive instrument 240 with one steerable section and figure 2b shows a non-limiting embodiment of a steerable invasive instrument 10 with two steerable sections.
[ 65 ] The steerable invasive instrument 240 as shown in figure 2a comprises an elongated shaft 242 having a proximal end part 241 and a distal end part 243. Here, the terms “proximal” and “distal” are to be understood from the perspective of a physician using the instrument. At the distal end part 243 a tool 2, for example a forceps, is arranged. Other examples of such a tool are a camera, a manual manipulator, e.g. a pair of scissors, or manipulators using an energy source, e.g. an electrical, ultrasonic or optical energy source. At the proximal end part 241 a handle 3 is arranged that is adapted for manipulating the tool 2, i.e. opening and closing the jaw of the forceps. To that effect, a control rod (not shown) is present within the elongated shaft 242, which rod connects the handle 3 with the tool 2.
The rod can be moved by the handle 3 and the movement of the rod is translated into a predetermined movement of the tool 2, as is known to persons skilled in the art and need no further explanation here. Also, the shaft 242 may comprise conducting wires to allow a current to flow to a tool, e.g. to heat said tool in order to perform a heat treatment within a human or animal body.
[ 66 ] Distal end part 243 is steerable and flexible. Also proximal end part 241 is flexible. Distal end part 243 can be bent by bending flexible proximal end part 241, as will become more clear from the below specification with reference to figures 3a to 3d.
[ 67 ] Figure 2b shows a side view of a steerable invasive instrument 10 with two steerable sections. The steerable instrument 10 comprises an elongated tubular body 18 having a proximal end part 11 including two actuation proximal zones 14, 15, a distal end part 13 including two flexible distal zones 16, 17, and a rigid intermediate part 12. The actuation proximal zones 14, 15 in the present embodiment are configured as flexible proximal zones, and will further be referred to as flexible proximal zones. At the distal end part 13 a tool, like a forceps 2 is arranged. At the proximal end part 11a handle 3 is arranged that is adapted for opening and closing the jaw of the forceps 2, like in the embodiment of Figure 2a.
[ 68 ] Figure 3a shows a longitudinal cross-section of a steerable instrument 2201 that can be applied in the steerable invasive instrument of figure 2a and comprises three co-axially arranged cylindrical elements, i.e. inner cylindrical element 2202, intermediate cylindrical element 2203 and outer cylindrical element 2204. Suitable materials to be used for making the cylindrical elements 2202, 2203, and 2204 include stainless steel, cobalt-chromium, shape memory alloy such as Nitinol®, plastic, polymer, composites or other cutable material.
[ 69 ] The inner cylindrical element 2202 comprises a first rigid end part 2221, which is located at the distal end part 13 of the instrument 2201, a first flexible part 2222, an intermediate rigid part 2223, a second flexible part 2224 and a second rigid end part 2225, which is located at the proximal end part 11 of the instrument 2201.
[ 70 ] The outer cylindrical element 2204 also comprises a first rigid end part 2241, a first flexible part 2242, an intermediate rigid part 2243, a second flexible part 2244 and a second rigid end part 2245. The lengths of the different parts of the cylindrical elements 2202 and 2204 are substantially the same so that when the inner cylindrical element 2202 is inserted into the intermediate cylindrical element 2203 which is inserted into the outer cylindrical element 2204, first flexible part 2222 is longitudinally aligned with first flexible part 2242 and second flexible part 2224 is longitudinally aligned with second flexible part 2244.
[ 71 ] The intermediate cylindrical element 2203 also has a first rigid end part 2331 and a second rigid end part 2335 which in the assembled condition are located between the corresponding rigid parts 2221, 2241 and 2225, 2245 respectively of the two other cylindrical elements 2202 and 2204, respectively. The intermediate part 2333 of the intermediate cylindrical element 2203 comprises three or more separate longitudinal elements which can have different forms and shapes as will be explained below. After assembly of the three cylindrical elements 2202, 2203 and 2204 whereby the element 2202 is inserted in the element 2203 and the two combined elements 2202, 2203 are inserted into the element 2204, at least the first rigid end part 2221 of the inner cylindrical element 2202, the first rigid end part 2331 of the intermediate cylindrical element 2203 and the first rigid end part 2241 of the outer cylindrical element 2204 at the distal end of the instrument are connected to each other such that they cannot longitudinally move relative to one another anymore. In the embodiment shown in figures 3a and 3b, preferably, also the second rigid end part 2225 of the inner cylindrical element 2202, the second rigid end part 2335 of the intermediate cylindrical element 2203 and the second rigid end part 2245 of the outer cylindrical element 2204 at the proximal end of the instrument are connected to each other such that they cannot longitudinally move relative to one another anymore and the three cylindrical elements 2202, 2203, 2204 form one integral unit.
[ 72 ] At one side of the instrument as shown in figures 3a to 3c, the connections between the three cylindrical elements 2202, 2203 and 2204 are implemented by means of the locking mechanisms as shown in and described with reference to figures la to If. However, since the snap-fit connection as shown in figures la to If can only be established by inserting one cylindrical element into another in a predefined direction, one cannot apply such a snap-fit direction at both ends of the instrument. So, at the other end the connections between the three cylindrical elements 2202, 2203, 2204 should be made in another way such as by welding, gluing or folding a lip present in one cylindrical element into a mating and aligned opening in an adjacent cylindrical element.
[ 73 ] Figure 3b shows the implementation where the distal ends of the cylindrical elements 2202, 2203, and 2204 are provided with the locking mechanisms of the present invention. To that end, inner cylindrical element 2202 is provided with opening 323 and self-guiding mechanism 325 as explained with reference to figures la to If. Intermediate cylindrical element 2203 is provided with inwardly bent, flexible lip 313 arranged to mate with opening 323, and provided with inwardly bent lip 317 arranged to cooperate with self-guiding mechanism 325 and to abut against edge 325c when the inner cylindrical element 2202 is locked into the intermediate cylindrical element 2203.
[ 74 ] Moreover, the intermediate cylindrical element 2203 is provided with its own self-guiding mechanism 335 which is constructed in an identical way as self-guiding mechanism 325. Only longitudinally retracted portion 335c of self-guiding mechanism 335 is shown in Figure 3b, which has the same function as longitudinally retracted portion 325c of inner cylindrical element 325. Also, intermediate cylindrical element 2203 has opening 333 designed for the same function as opening 323 in the inner cylindrical element 2202.
[ 75 ] Outer cylindrical element 2204 is provided with an inwardly bent, flexible lip 337 arranged to mate with opening 333, and provided with inwardly bent lip 339 arranged to cooperate with self-guiding mechanism 335 and to abut against edge 335c when the intermediate cylindrical element 2203 is locked into the outer cylindrical element 2204.
[ 76 ] Figure 3b shows the situation where the self-guiding mechanisms 325 and 335, respectively, are provided on the respective cylindrical element that is to be inserted into another one to which it is to be fixedly connected. However, as explained, that may be the other way around.
[ 77 ] Moreover, in a further alternative embodiment, intermediate cylindrical element 2203 is provided with two flexible lips like the lips 337 and 339 of the outer cylindrical element 2204, which lips are then bent outwardly. In this embodiment, the outer cylindrical element 2204 is provided with an opening like opening 333 and a self-guiding mechanism like self-guiding mechanism 335.
[ 78 ] In a still further embodiment, the invention relates to a steerable instrument only comprising cylindrical elements 2202 and 2203 or cylindrical elements 2203 and 2204.
[ 79 ] In the case where only cylindrical elements 2202 and 2203 are provided, intermediate cylindrical element 2203 does not have the opening 333 and the self-guiding mechanism 335. Note that in this case, the opening 323 and self-guiding mechanism 325 may be applied on the intermediate cylindrical element 2203 instead of on the inner cylindrical element 2202, whereas, then, the inner cylindrical element comprises the lips 313, 317, be it that they are then bent outwardly.
[ 80 ] In the case where only cylindrical elements 2203 and 2204 are provided, intermediate cylindrical element 2203 does not have the lips 313 and 317. Note that in this case, the opening 333 and self-guiding mechanism 335 may be applied on the outer cylindrical element 2204 instead of on the intermediate cylindrical element 2203, whereas, then, the intermediate cylindrical element 2203 comprises the lips 337, 339, be it that they are then bent outwardly.
[ 81 ] In the embodiment shown in figure 3 b the intermediate part 2333 of intermediate cylindrical element 2203 comprises a number of longitudinal elements 2338 with a, preferably, uniform cross-section so that the intermediate part 2333 has the general shape and form as shown in the unrolled condition of the intermediate cylindrical element 2203 in figure 3c. From figure 3c it also becomes clear that the intermediate part 2333 is, preferably, formed by a number of over the circumference of the intermediate cylindrical part 2203 equally spaced parallel longitudinal elements 2338. Advantageously, the number of longitudinal elements 2338 is at least three, so that the instrument 2201 becomes fully controllable in any direction, but any higher number is possible as well. Preferably, the number of longitudinal elements 2338 is 6 or 8.
[ 82 ] As explained in EP08773760.7 of the present applicant, the longitudinally elements 2338 are preferably separated from one another by means of spacers such that they cannot tangentially but only longitudinally move relative to one another in the assembled condition.
[ 83 ] Longitudinal steering elements 2338 may, at least in part, be spiraling about a longitudinal axis of the instrument such that an end portion of a respective steering element at the proximal portion of the instrument is arranged at another angular orientation about the longitudinal axis than an end portion of the same longitudinal steering element at the distal portion of the instrument. Were the longitudinal steering elements arranged in a linear orientation, than a bending of the instrument at the proximal portion in a certain plane would result in a bending of the instrument at the distal portion in the same plane but in a 180 degrees opposite direction. This spiral construction of the longitudinal steering elements allows for the effect that bending of the instrument at the proximal portion in a certain plane may result in a bending of the instrument at the distal portion in another plane, or in the same plane in the same direction. A preferred spiral construction is such that the end portion of a respective steering element at the proximal portion of the instrument is arranged at an angular shifted orientation of 180 degrees about the longitudinal axis relative to the end portion of the same longitudinal steering element at the distal portion of the instrument. However, e.g. any other angular shifted orientation, e.g. 90 degrees, is within the scope of this document. The slits may be dimensioned such that movement of a longitudinal element is guided by adjacent longitudinal elements when provided in place in a steerable instrument.
[ 84 ] The production of such an intermediate part is most conveniently done by injection moulding or plating techniques or starting from a cylindrical tube with the desired inner and outer diameters and removing parts of the wall of the cylindrical tube required to end up with the desired shape of the intermediate cylindrical element 2203. However, alternatively, any 3D printing method can be used.
[ 85 ] The removal of material can be done by means of different techniques such as laser cutting, photochemical etching, deep pressing, conventional chipping techniques such as drilling or milling, high pressure water jet cutting systems or any suitable material removing process available. Preferably, laser cutting is used as this allows for a very accurate and clean removal of material under reasonable economic conditions. The above mentioned processes are convenient ways as the member 2203 can be made so to say in one process, without requiring additional steps for connecting the different parts of the intermediate cylindrical member as required in the conventional instruments, where conventional steering cables must be fixedly connected in some way to the end parts. The same type of technology can be used for producing the inner and outer cylindrical elements 2202 and 2204 with their respective flexible parts 2222, 2224, 2242 and 2244.
[ 86 ] In the above embodiments, the proximal portions and distal portions are constructed in a similar way. However, that need not be the case always as will be explained now.
[ 87 ] E.g., the proximal portion may have a wider diameter as shown in figure 3d, which shows a special embodiment of an instrument according to the invention. The inner cylindrical element 2202 is composed of a first rigid end part 2225, a first flexible part 2224, an intermediate rigid part 2223, a second flexible part 2222 and a second rigid end part 2221 which is normally used as the operating part of the instrument in that it serves to steer the other end of the unit. The outer cylindrical element 2204 is in the same way composed of a first rigid part 2245 , a flexible part 2244, an intermediate rigid part 2243, a second flexible part 2242 and a second rigid part 2241. The intermediate cylindrical element 2203 also has a first rigid end part 2335 and a second rigid end part 2331 which in the assembled condition are located between the corresponding rigid parts 2225,2245 and 2221, 2241, respectively, of the two other cylindrical elements 2202, 2204. In the embodiment shown the longitudinal elements 2338 are of the type shown in figure 3b, but it will be obvious that any other type described above may be used as well. So far the construction is comparable to the instruments described above.
[ 88 ] The main difference with respect to the above embodiments is the use of a different set of diameters for some parts of the instrument. In the embodiment shown in figure 3d the parts 2222, 2221, 2331, 2242 and 2241 have a larger diameter than the other parts. In the parts 2223, 2338 and 2243 frusto-conical portions have been made in order to connect the small diameter parts with the large diameter parts. As shown in figure 3d the different parts can easily be assembled by inserting one into the other. The main reason, however, to have such an instrument with different diameters is that by using an operating part with a larger diameter, the movement of the other end is amplified, whereas if a smaller diameter is used the movement of the other end is reduced. Dependent of the application and its requirements larger diameters can be used to have the amplified movement or smaller diameters can be used to reduce the movement and increase accuracy.
[ 89 ] At the distal end of the instrument as shown in figure 3d, the connections between the three cylindrical elements 2202, 2203 and 2204 are implemented by means of the locking mechanism as shown in and described with reference to figure 3b. At the proximal end the attachments between the three cylindrical elements may be made by welding, gluing or folding a lip present in one cylindrical element into a mating and aligned opening in an adjacent cylindrical element.
[ 90 ] Figure 4a provides a detailed perspective view of the distal portion of the elongated tubular body 18 of the steerable instrument 10 of Figure 2b and shows that the elongated tubular body 18 comprises of a number of co-axially arranged layers or cylindrical elements including an outer cylindrical element 104 that ends after the first flexible distal zone 16 at the distal end portion 13. The distal end portion 13 of the outer cylindrical element 104 is connected to a cylindrical element 103 located within and adjacent to the outer cylindrical element 104 by means of locking mechanisms as shown in and discussed with reference to figures la to If.
[ 91 ] The distal end part 13 includes three co-axially arranged layers or cylindrical elements being an inner cylindrical element 101, a first intermediate cylindrical element 102 and a second intermediate cylindrical element 103 (cf., also figure 4b). The distal ends of inner cylindrical element 101, first intermediate cylindrical element 102 and second intermediate cylindrical element 103 are all three locked to one another. To that end, second intermediate cylindrical element 103 is, e g., provided with inwardly bent lips 337, (338) 339 that cooperate with a locking mechanism 333, 335 provided at a distal end portion of first intermediate cylindrical element 102. Moreover, first intermediate cylindrical element 102 is connected to inner cylindrical element 101 by means of the locking mechanism including lips 313, 317, opening 323 and self-guiding mechanism 325. However, variants to this locking mechanism as discussed with reference to figures la to If may applied instead.
[ 92 ] Outer cylindrical element 104 is provided with a self-guiding mechanism 336 that is designed in the same way as self-guiding mechanisms 325, 335, as well as an opening 330 that is arranged to make a snap-fit connection with an outwardly bent lip (not shown) on second intermediate cylindrical element 103. Second intermediate cylindrical element 103 is provided with one or more outwardly bent lips 332, 334 designed to abut against respective longitudinally retracted portions of self-guiding mechanism 336 in the locked condition between second intermediate cylindrical element 103 and outer cylindrical element 104.
[ 93 ] It will be clear to the skilled person that the elongated tubular body 18 as shown in figure 4a comprises four cylindrical elements in total. The elongated tubular body 18 according to the embodiment shown in figure 4a comprises two intermediate cylindrical elements 102 and 103 in which the steering members of the steering arrangement are arranged. The steering arrangement in the exemplary embodiment of the elongated tubular body 18 as shown in figure 4a comprises the two flexible zones 14, 15 at the proximal end part 11 of the elongated tubular body 18, the two flexible zones 16, 17 at the distal end part 13 of the elongated tubular body 18 and the steering members that are arranged between related flexible zones at the proximal 11 and distal 13 end parts. An exemplary actual arrangement of the steering members is shown in figure 4b, which provides a schematic longitudinal cross-sectional view of the exemplary embodiment of the elongated tubular body 18 as shown in figure 4a.
[ 94 ] Figure 4b shows the four layers or cylindrical elements mentioned above, i.e. the inner cylindrical element 101, the first intermediate cylindrical element 102, the second intermediate cylindrical element 103, and the outer cylindrical element 104.
[ 95 ] The inner cylindrical element 101, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 111, which is arranged at the distal end part 13 of the steerable instrument 10, a first flexible portion 112, a first intermediate rigid portion 113, a second flexible portion 114, a second intermediate rigid portion 115, a third flexible portion 116, a third intermediate rigid portion 117, a fourth flexible portion 118, and a rigid end portion 119, which is arranged at the proximal end portion 11 of the steerable instrument 10.
[ 96 ] The first intermediate cylindrical element 102, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 121, a first flexible portion 122, a first intermediate rigid portion 123, a second flexible portion 124, a second intermediate rigid portion 125, a third flexible portion 126, a third intermediate rigid portion 127, a fourth flexible portion 128, and a rigid end portion 129. The longitudinal dimensions of the rigid ring 121, the first flexible portion 122, the first intermediate rigid portion 123, the second flexible portion 124, the second intermediate rigid portion 125, the third flexible portion 126, the third intermediate rigid portion 127, the fourth flexible portion 128, and the rigid end portion 129 of the first intermediate element 102, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, the second intermediate rigid portion 115, the third flexible portion 116, the third intermediate rigid portion 117, the fourth flexible portion 118, and the rigid end portion 119 of the inner cylindrical element 101, respectively, and are coinciding with these portions as well. In this description “approximately equal” means that respective same dimensions are equal within a margin of less than 10%, preferably less than 5%.
[ 97 ] The second intermediate cylindrical element 103, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 131, a first flexible portion 132, a second rigid ring 133, a second flexible portion 134, a first intermediate rigid portion 135, a first intermediate flexible portion 136, a second intermediate rigid portion 137, a second intermediate flexible portion 138, and a rigid end portion 139. The longitudinal dimensions of the first rigid ring 131, the first flexible portion 132 together with the second rigid ring 133 and the second flexible portion 134, the first intermediate rigid portion 135, the first intermediate flexible portion 136, the second intermediate rigid portion 137, the second intermediate flexible portion 138, and the rigid end portion 139 of the second intermediate cylinder 103, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, the second intermediate rigid portion 115, the third flexible portion 116, the third intermediate rigid portion 117, the fourth flexible portion 118, and the rigid end portion 119 of the first intermediate element 102, respectively, and are coinciding with these portions as well.
[ 98 ] The outer cylindrical element 104, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 141, a first flexible portion 142, a first intermediate rigid portion 143, a second flexible portion 144, and a second rigid ring 145. The longitudinal dimensions of the first flexible portion 142, the first intermediate rigid portion 143 and the second flexible portion 144 of the outer cylindrical element 104, respectively, are aligned with, and preferably approximately equal to the longitudinal dimension of the second flexible portion 134, the first intermediate rigid portion 135 and the first intermediate flexible portion 136 of the second intermediate element 103, respectively, and are coinciding with these portions as well. The rigid ring 141 has approximately the same length as the rigid ring 133 and is fixedly attached thereto, by a locking mechanism as shown in and discussed with reference to figures la to If.
Preferably, the rigid ring 145 overlaps with the second intermediate rigid portion 137 only over a length that is required to make an adequate fixed attachment between the rigid ring 145 and the second intermediate rigid portion 137, respectively, e.g. by spot welding or gluing, or by folding a lip present in one cylindrical element into a mating and aligned opening in an adjacent cylindrical element. The rigid rings 111, 121 and 131 are attached to each other, also by a locking mechanism as shown in and discussed with reference to Figures la to If.
[ 99 ] In an embodiment, the rigid end portions 119, 129 and 139 are attached together as well e g. by spot welding or gluing, or by folding a lip present in one cylindrical element into a mating and aligned opening in an adjacent cylindrical element. However, the construction may be such that the diameter of the cylindrical elements at the proximal portion is larger, or smaller, with respect to the diameter at the distal portion. In such an embodiment the construction at the proximal portion differs from the one shown in figure 4b. As a result of the increase in diameter an amplification is achieved, i.e., the bending angle of a flexible zone at the distal portion will be larger than the bending angle of a corresponding flexible portion at the proximal portion. This has been explained for a single steerable, flexible zone in more detail above with reference to figure 3d.
[ 100 ] The inner and outer diameters of the cylindrical elements 101, 102, 103, and 104 are chosen in such a way that at a same location along the elongated tubular body 18 that the outer diameter of inner cylindrical element 101 is slightly less than the inner diameter of the first intermediate cylindrical element 102, the outer diameter of the first intermediate cylindrical element 102 is slightly less than the inner diameter of the second intermediate cylindrical element 103 and the outer diameter of the second intermediate cylindrical element 103 is slightly less than the inner diameter of the outer cylindrical element 104, in such away that a sliding movement of the adjacent cylindrical elements with respect to each other is possible. The dimensioning should be such that a sliding fit is provided between adjacent elements. A clearance between adjacent elements may generally be in the order of 0.02 to 0.1 mm, but depends on the specific application and material used. The clearance is, preferably, smaller than a wall thickness of the longitudinal elements to prevent an overlapping configuration thereof. Restricting the clearance to about 30% to 40% of the wall thickness of the longitudinal elements is generally sufficient.
[ 101 ] As can be seen in figure 4b, flexible zone 14 of the proximal end part 11 is connected to the flexible zone 16 of the distal end part 13 by portions 134, 135 and 136, of the second intermediate cylindrical element 103, which form a first set of longitudinal steering members of the steering arrangement of the steerable instrument 10. Furthermore, flexible zone 15 of the proximal end part 11 is connected to the flexible zone 17 of the distal end part 13 by portions 122, 123, 124, 125, 126, 127, and 128 of the first intermediate cylindrical element 102, which form a second set of longitudinal steering members of the steering arrangement. [102] Suitable materials to be used for making the cylindrical elements 101, 102, 103, and 104 include stainless steel, cobalt-chromium, shape memory alloy such as Nitinol®, plastic, polymer, composites or other cutable material.
[ 103 ] The use of the construction as described above allows the steerable instrument 10 to be used for double bending. The working principle of this construction will be explained with respect to the examples shown in figures 4c and 4d.
[ 104 ] For the sake of convenience, as shown in figures 4b, 4c and 4d,the different portions of the cylindrical elements 101, 102, 103, and 104 have been grouped into zones 151 - 160 that are defined as follows. Zone 151 comprises the rigid rings 111, 121, and 131. Zone 152 comprises the portions 112, 122, and 132. Zone 153 comprises the rigid rings 133 and 141 and the portions 113 and 123.
Zone 154 comprises the portions 114, 124, 134 and 142. Zone 155 comprises the portions 115, 125, 135 and 143. Zone 156 comprises the portions 116, 126, 136 and 144. Zone 157 comprises the rigid ring 145 and the parts of the portions 117, 127, and 137 coinciding therewith. Zone 158 comprises the parts of the portions 117, 127, and 137 outside zone 157. Zone 159 comprises the portions 118, 128 and 138. Finally, zone 160 comprises the rigid end portions 119, 129 and 139.
[ 105 ] In order to deflect at least a part of the distal end part 13 of the steerable instrument 10, it is possible to apply a bending force, in any radial direction, to zone 158. According to the examples shown in figures 4c and 4d, zone 158 is bent downwards with respect to zone 155. Consequently, zone 156 is bent downwards. Because of the first set of steering members comprising portions 134, 135, and 136 of the second intermediate cylindrical element 103 that are arranged between the second intermediate rigid portion 137 and the second rigid ring 133, the downward bending of zone 156 is transferred by a longitudinal displacement of the first set of steering members into an upward bending of zone 154 with respect to zone 155. This is shown in both figures 4c and 4d.
[106] It is to be noted that the exemplary downward bending of zone 156, only results in the upward bending of zone 154 at the distal end of the instrument as shown in figure 4c. Bending of zone 152 as a result of the bending of zone 156 is prevented by zone 153 that is arranged between zones 152 and 154. When subsequently a bending force, in any radial direction, is applied to the zone 160, zone 159 is also bent. As shown in figure 4d, zone 160 is bent in an upward direction with respect to its position shown in figure 4c. Consequently, zone 159 is bent in an upward direction. Because of the second set of steering members comprising portions 122, 123, 124, 125, 126, 127 and 128 of the first intermediate cylindrical element 102 that are arranged between the rigid ring 121 and the rigid end portion 129, the upward bending of zone 159 is transferred by a longitudinal displacement of the second set of steering members into a downward bending of zone 152 with respect to its position shown in figure 4c.
[ 107 ] Figure 4d further shows that the initial bending of the instrument in zone 154 as shown in figure 4c will be maintained because this bending is only governed by the bending of zone 156, whereas the bending of zone 152 is only governed by the bending of zone 159 as described above. Due to the fact that zones 152 and 154 are bendable independently with respect to each other, it is possible to give the distal end part 13 of the steerable instrument 10 a position and longitudinal axis direction that are independent from each other. In particular the distal end part 13 can assume an advantageous S-like shape.
[ 108 ] Obviously, it is possible to vary the lengths of the flexible portions shown in figures 4b to 4d as to accommodate specific requirements with regard to bending radii and total lengths of the distal end part 13 and the proximal end part 11 of the steerable instrument 10 or to accommodate amplification or attenuation ratios between bending of at least a part of the proximal end part 11 and at least a part of the distal end part 13.
[ 109 ] The steering arrangement of the steerable invasive instrument 10 may comprise conventional steering cables as steering members that are fixedly attached to the respective rigid rings 121, 133. However due to well-known disadvantages of conventional steering cables, the steering members preferably comprise one or more sets of longitudinal elements that form integral parts of the one or more intermediate cylindrical elements 102, 103. Preferably, the longitudinal elements comprise remaining parts of the wall of an intermediate cylindrical element 102, 103 after the wall of the intermediate cylindrical element 102, 103 has been provided with longitudinal slits that define the remaining longitudinal steering elements.
[110] Further details regarding the fabrication of the latter longitudinal steering elements have been provided with reference to figures 3a to 3c regarding an exemplary embodiment of a steerable instrument that comprises only one flexible zone at both its proximal 11 and distal end 13 parts.
[ 111 ] Figure 4e shows an exemplary embodiment of longitudinal (steering) elements 4 that have been obtained after providing longitudinal slits 5 to the wall of the second intermediate cylindrical element 103 that interconnects proximal flexible zone 14 and distal flexible zone 16 as described above. I.e., longitudinal steering elements 4 are, at least in part, spiraling about a longitudinal axis of the instrument such that an end portion of a respective steering element 4 at the proximal portion of the instrument is arranged at another angular orientation about the longitudinal axis than an end portion of the same longitudinal steering element 4 at the distal portion of the instrument. Were the longitudinal steering elements 4 arranged in a linear orientation, than a bending of the instrument at the proximal portion in a certain plane would result in a bending of the instrument at the distal portion in the same plane but in a 180 degrees opposite direction. This spiral construction of the longitudinal steering elements 4 allows for the effect that bending of the instrument at the proximal portion in a certain plane may result in a bending of the instrument at the distal portion in another plane, or in the same plane in the same direction. A preferred spiral construction is such that the end portion of a respective steering element 4 at the proximal portion of the instrument is arranged at an angular shifted orientation of 180 degrees about the longitudinal axis relative to the end portion of the same longitudinal steering element 4 at the distal portion of the instrument. However, e.g. any other angular shifted orientation, e.g. 90 degrees, is within the scope of this document. The slits may be dimensioned such that movement of a longitudinal element is guided by adjacent longitudinal elements when provided in place in a steerable instrument.
[ 112 ] The flexible portions 112, 132, 114, 142, 116, 144, 118, and 138 as shown in figure 4b, as well as the flexible parts 2222, 2224, 2242, and 2244 shown in figures 3a and 3b can be obtained by the methods described in the European patent application 08 004 373.0 filed on 10.03.2008, page 5, lines 15-26, but any other suitable process can be used to make flexible portions.
[113] Such flexible parts may have a structure as shown in figure 4a. I.e., the flexibility may be obtained by a plurality of slits 14a, 15a, 16a, 17a. E.g., two circumferential slits may be provided in a cylindrical element along a same circumferential line where both slits are located at a certain distance from one another. A plurality of identical sets of circumferential slits 14a, 15a, 16a, 17a is provided at a plurality of distances in the longitudinal direction of the instrument, where consecutive sets are arranged at an angular rotated position, e.g. each time 90 degrees rotated. In such an arrangement, all parts of the cylindrical element are still connected to each other.
[ 114 ] Furthermore, if the portions 122, 123, 124, 125, 126, 127, and 128 of the first intermediate cylindrical element 102 and the portions 134, 135, and 136 of the second intermediate cylindrical element 103 that respectively form the first and second set of longitudinal steering members, as shown in figure 4b, are implemented as longitudinal steering elements 4 as shown in figure 4e, the fabrication methods described above can be used. The same applies to the longitudinal elements 2338 of figures 3b and 3c.
[ 116 ] The different co-axially arranged layers or cylindrical elements 101, 102, 103, 104, 2202, 2203 and 2204 as described above in relation to the exemplary embodiments of the steerable instruments shown in figures 4b and 3 a, respectively, may be produced by any of the known methods, provided that they are suitable to make a multilayer system. A multilayer system is to be understood as being a steerable instrument that comprises at least two separate sets of longitudinal elements 4, 2338 for transferring the movement of the proximal end part to the distal end part. The assembly of the different cylindrical elements can be realized in the same way as well.
[116] Widening of the instrument with increasing diameter towards the proximal portions can also be applied in an instrument with more than two bendable portions, as, e.g., shown in figure 5. In figure 5 there is shown an instrument having four layers and as such the instrument is comparable to the instrument of figure 4b but the actuating portion of the cylindrical elements has a larger diameter compared to the handling end portion and in the zone 155 a frusto-conical part has been incorporated. As a result of the larger diameter of the actuating portion at the proximal end the movement of the handling portion at the distal end will be amplified upon bending, thereby amplifying the movement of the handling head. It is also possible to work in the opposite direction with a handling portion at the distal end with a larger diameter than the actuating portion at the proximal end, whereby the degree of movement is decreased, thereby improving accuracy of movement of the handling head.
[117] The outer cylindrical element is attached to the intermediate cylindrical element at location 153 whereas the intermediate cylindrical element is attached to the inner cylindrical element at location 151. In figure 5 these attachments at locations 151 and 153 are only schematically indicated. However, they may have the same design as the ones shown in figure 4a and 4b.
[118] Although in the above explanation, only locking mechanisms between 2, 3 and 4 cylindrical elements have been explained, it will be apparent to persons skilled in the art that they can be applied to any higher number of insertable cylindrical elements as well whereas such cylindrical elements may be made of any suitable known material, including all plastics, composites and metals.
Claims (13)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2015179A NL2015179B1 (en) | 2015-07-16 | 2015-07-16 | A set of lockable cylindrical elements and a steerable instrument comprising same. |
| PCT/NL2016/050522 WO2017010883A2 (en) | 2015-07-16 | 2016-07-14 | A set of lockable cylindrical elements and a steerable instrument comprising same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| NL2015179A NL2015179B1 (en) | 2015-07-16 | 2015-07-16 | A set of lockable cylindrical elements and a steerable instrument comprising same. |
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| NL2015179B1 true NL2015179B1 (en) | 2017-02-02 |
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| NL2016900B1 (en) | 2016-06-06 | 2017-12-13 | Fortimedix Surgical B V | Steerable instrument comprising a cylindrical diameter adaptation section |
| NL2019175B1 (en) | 2017-07-04 | 2019-01-14 | Fortimedix Surgical B V | Steerable instrument comprising a radial spacers between coaxial cylindrical elements |
| AU2019412444A1 (en) * | 2018-12-28 | 2021-07-15 | Uni-Troll Europe Aps | A coupling system |
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| WO2014039054A1 (en) * | 2012-09-07 | 2014-03-13 | Hassoun Basel S | Improved surgical instrument |
| WO2015084157A1 (en) * | 2013-12-04 | 2015-06-11 | Fortimedix Surgical B.V. | Access device and assembly comprising such device |
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| EP2256355A1 (en) * | 2009-05-29 | 2010-12-01 | Agatsuma Co., Ltd. | Connector for Jungle Gym and Jungle Gym Using Same |
| US20140376990A1 (en) * | 2013-06-24 | 2014-12-25 | Hsin-Yuan Lai | Collapsible Tubular Rod |
| DE102014222009A1 (en) * | 2013-11-28 | 2015-05-28 | Bosch Power Tools (China) Co., Ltd. | Pipe set and electric machine tool with a pipe set |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017010883A2 (en) | 2017-01-19 |
| WO2017010883A3 (en) | 2017-06-01 |
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