JP5886350B2 - Stylet - Google Patents

Description

  The present invention relates to a stylet. More particularly, the present invention relates to a stylet for adjusting the flexibility of an insertion portion of an endoscope while being inserted through a forceps hole of the endoscope.

  In recent years, endoscopes have been used to examine the esophagus, stomach, duodenum, etc. via the oral cavity, and the rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum, etc. have been examined via the anus. Yes. The large intestine, especially from the anus to the transverse colon, is winding. Generally, the insertion portion of the endoscope is inserted along this winding path. After the distal end of the insertion portion reaches the splenic curved portion that is the entrance to the transverse colon, in order to facilitate further insertion, the bending portion of the sigmoid colon is made to be straight by increasing the rigidity of the insertion portion. Straighten as much as possible.

  In order to adjust the rigidity of the insertion portion, a member called a stylet is used. The stylet is an elongated member and is inserted into a forceps hole (forceps channel) formed along the insertion portion of the endoscope. In addition to the forceps hole, a CCD camera cable, a light guide, a water supply (air supply) tube, and the like are inserted into the insertion portion along the longitudinal direction.

  In the market, there is a strong demand for reducing the diameter of endoscopes. With the demand for reducing the diameter of the endoscope, the diameter of the stylet is also required. Another reason for reducing the diameter of the stylet is that the stylet can be cleaned and sucked while the stylet is inserted into the forceps channel. Further, at the same time as reducing the diameter, further higher rigidity is required. Of course, it is not allowed to lose the flexibility to be inserted along the sigmoid colon.

  As the stylet, those disclosed in JP2003-180622A, JP2009-189399A, and the like are known.

  Both of the stylets disclosed in the above-mentioned publications are ones in which a single operation wire is inserted inside a long thin coil, and a single tube is arranged in a plurality of tubes arranged in series. A wire is inserted. In the former case, when the operation wire is pulled, the coil is compressed and the rigidity increases, and when the operation wire is loosened, the coil approaches the free length and the rigidity decreases (flexibility improves). is there. The latter tube body has a certain degree of elasticity and has a property of being compressed and hardened. In this stylet, when the operation wire is pulled, the tubes are pressed against each other to increase the rigidity, and when the operation wire is loosened, the tubes are separated from each other and the rigidity is decreased (flexibility is increased). That's it.

  It is difficult to obtain the required high rigidity simply by bringing the tubular bodies into pressure contact according to the pulling force of the operation wire. The same is true for a stylet using a coil. When the bending rigidity of the coil is increased, it is difficult to obtain high flexibility. The stylet proposed in the above publication does not reach the required level of maximum rigidity that can be achieved when the operation wire is pulled. If there is a demand for a smaller diameter, it will be difficult to achieve higher rigidity.

JP 2003-180622 A JP 2009-189399 A

  The present invention has been made in view of the present situation described above, and an object of the present invention is to provide a stylet that can be adjusted to high flexibility and can achieve high rigidity while being reduced in diameter. It is said.

The stylet according to the present invention is:
A stylet that adjusts the flexibility of the insertion portion of the endoscope while being inserted through the forceps hole of the endoscope,
A plurality of tubular elements each having a through hole;
A linear member for operation inserted through the through holes of the plurality of tubular elements;
A resilient member disposed at the end of the tubular element and capable of resiliently separating adjacent tubular elements;
Each tubular element has a fitting portion that can be fitted with an adjacent tubular element;
By pulling the linear member, the tubular elements can be fitted with each other with the elastic member interposed therebetween.

Preferably, the fitting portion is
A fitting hole formed in the longitudinal direction at one end of the tubular element;
The other end portion of the tubular element is provided with a fitting protrusion that protrudes in the longitudinal direction and can be fitted into the fitting hole.

Preferably, the elastic member is
A coil spring that can be mounted inside the fitting hole in a state of being externally fitted to the linear member, or
A coil spring that can be mounted in a state of being externally fitted to the fitting protrusion.

Preferably, the elastic member is
A magnet attached to the back end of the fitting hole and the tip of the fitting projection so as to be repelled with each other, or
It is a magnet attached to the front end opening of the fitting hole and the base end of the fitting projection so as to be repelled from each other.

  According to the stylet according to the present invention, it is possible to achieve high rigidity as well as to reduce the diameter while enabling adjustment to high flexibility.

FIG. 1A is a front view showing a state in which a stylet according to an embodiment of the present invention has high rigidity, and FIG. 1B shows that the stylet has low rigidity (high flexibility). It is a front view which shows the state which became. 2 (a) is a partially cutaway front view showing a state in which the tubular elements of the stylet in FIG. 1 are separated from each other, and FIG. 2 (b) is a state in which the tubular elements are fitted to each other. It is a partially cutaway front view shown. FIG. 3 (a) is a partially cutaway front view showing a state in which the tubular elements of the stylet according to another embodiment of the present invention are separated from each other, and FIG. It is a partially cutaway front view showing the combined state. FIG. 4A is a partially cutaway front view showing a state in which the tubular elements of the stylet according to still another embodiment of the present invention are separated from each other, and FIG. It is a partially notched front view which shows the state which fitted together. FIG. 5 (a) is a partially cutaway front view showing a state in which the tubular elements of the stylet according to still another embodiment of the present invention are separated from each other, and FIG. It is a partially notched front view which shows the state which fitted together.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  A stylet 1 shown in FIG. 1 includes a large number of tubular elements (hereinafter also referred to as pipes) 2 and a linear member for operation inserted into an inner space 3 (see FIG. 2 and subsequent figures) 3 of the pipe 2 (see FIG. 2 and subsequent figures). (Hereinafter also referred to as an operation wire) 4. The distal end of the operation wire 4 is fixed to the pipe 2a located at the distal end 1a of the stylet 1 by welding or the like. The proximal end of the operation wire 4 is connected to the operation unit 6 via a pipe stopper 5 provided in an endoscope (not shown). This stylet 1 is inserted into a forceps hole of an insertion portion of an endoscope (not shown). The tip 1a of the stylet 1 is located at the tip of the forceps hole.

  The pipe 2 is preferably formed from stainless steel, titanium, titanium alloy, cobalt alloy, nitinol (nickel titanium alloy), superelastic alloy, other biocompatible metals or alloys. The operation wire 4 is preferably made of stainless steel, titanium, titanium alloy, cobalt alloy, nitinol (nickel titanium alloy), superelastic alloy, or other biocompatible metal or alloy. The outer diameter of the pipe 2 is preferably 1.0 mm or greater and 3.0 mm or less. The length of the pipe 2 is preferably 5 mm or more and 30 mm or less. The inner diameter of the pipe 2 is preferably 0.3 mm or more and 2.0 mm or less.

  FIG. 1A shows the stylet 1 in a high rigidity state by pulling the operation wire 4 in the arrow A direction. The stylet 1 is straightened by pulling the operation wire 4. That is, the entire stylet 1 has a rod shape. FIG. 1B shows the stylet 1 in a state of low rigidity (high flexibility) by completely loosening the operation wire 4 in the arrow B direction. The stylet 1 does not simply press the pipes together by pulling the operation wire, unlike the conventional stylet described above. The stylet 1 is connected in a form of fitting with each other so that the pipes 2 are not bent by pulling the operation wire 4.

  FIG. 2 shows the structure of a part of the stylet 1 in detail. In the stylet 1, the pipes 2 can be connected to each other by a kind of inlay joint. FIG. 2A shows the stylet 1 in a state where the operation wire 4 is completely loosened. The pipes 2 are separated without fitting. The stylet 1 in FIG. 2A is in the same state as the stylet 1 shown in FIG. The stylet 1 in this state has rigidity substantially equal to the rigidity of the operation wire 4 itself. The stylet 1 in this state is rich in flexibility. In the present embodiment, the pipe 2 has a uniform outer diameter, and all the pipes 2 have the same outer diameter. However, it is not limited to such a configuration.

  A fitting projection 8 projects from one end of the pipe body 7 of the pipe 2. The fitting protrusion 8 is for fitting with a fitting hole 9 described later of the adjacent pipe 2. The fitting protrusion 8 and the fitting hole 9 constitute a fitting portion of the pipe 2. The fitting protrusion 8 is provided so as to protrude outward in the axial direction coaxially with the pipe body 7. The fitting protrusion 8 is a portion that is reduced in diameter from the pipe body 7 and has a uniform outer diameter over the entire length. An inner space (hereinafter also referred to as a through hole) 3 of the pipe 2 is formed with the same inner diameter from the pipe body 7 to the tip of the fitting protrusion 8.

  A compression coil spring (hereinafter simply referred to as a coil spring) 10 as an elastic member is fitted on the outer peripheral surface of the fitting protrusion 8 in a free length state (free state). That is, neither compressed nor pulled. In the present embodiment, the free length of the coil spring 10 and the axial length of the fitting protrusion 8 are substantially the same. The free length of the coil spring 10 is preferably slightly longer than the axial length of the fitting protrusion 8. By so doing, when the operation wire 4 is completely loosened, the fitting protrusion 8 and the fitting hole 9 are reliably disengaged. One end of the coil spring 10 may be fixed to the base end side of the fitting protrusion 8 by welding or the like. The outer diameter of the coil spring 10 in the close contact state is substantially equal to the outer diameter of the pipe body 7.

  The coil spring 10 is preferably made of stainless steel, titanium, titanium alloy, cobalt alloy, nitinol (nickel titanium alloy), superelastic alloy, or other biocompatible metal or alloy. The wire diameter of the coil spring 10 is preferably 0.2 mm or more and 0.5 mm or less. The spring constant of the coil spring 10 is preferably 0.5 N / mm or more and 10 N / mm or less. When the coil spring 10 having the above size range is used, the fitting length is preferably 1 mm or more and 10 mm or less. The fitting length refers to the axial length in which the fitting protrusion and the fitting hole are fitted. For example, the depth of the fitting hole 9 in the stylet 1 of FIG. 2 and the length of the fitting protrusion 17 in the stylet 15 of FIG. 3 correspond to this fitting length.

  A fitting hole 9 into which the fitting protrusion 8 of the adjacent pipe 2 can be fitted is formed at the other end of the pipe body 7. The fitting hole 9 is formed coaxially with the pipe body 7. The inner diameter of the fitting hole 9 is slightly larger than the outer diameter of the fitting protrusion 8. Since the inner diameter of the fitting hole 9 is much smaller than the outer diameter of the coil spring 10 in a free state, the coil spring 10 cannot enter the fitting hole 9. In this embodiment, the depth of the fitting hole 9 is slightly larger than the value obtained by subtracting the contact length of the coil spring 10 from the length of the fitting protrusion 8 (see FIG. 2B). Neither the fitting protrusion 8 nor the fitting hole 9 is formed at the tip of the pipe 2a (see FIG. 1) located at the tip 1a of the stylet 1.

  FIG. 2B shows the stylet 1 in a state where the operation wire 4 is pulled. The pipes 2 are engaged with each other. The stylet 1 in FIG. 2 (b) is in the same state as the stylet 1 shown in FIG. 1 (a). The fitting protrusion 8 of the pipe 2 is fitted in the fitting hole 9 of the adjacent pipe 2. The coil spring 10 is pinched and compressed by the step portion 11 between the pipe body 7 and the fitting protrusion 8 and the end face of the adjacent pipe 2. Here, it is not necessary to pull the operation wire 4 until the coil spring 10 is in close contact. This is because the pipes 2 can be fitted to each other even if they are not in close contact.

  When the pipes 2 are connected to each other by the above-mentioned spigot joint, the stylet 1 becomes a rod shape. Since all the pipes 2 are made of metal, it is obvious that the stylet 1 in this state has high rigidity. On the other hand, when the fitting between the pipes 2 is released, the stylet 1 has substantially the same rigidity as the operation wire 4 itself. The stylet 1 in this state is rich in flexibility. Since the metal pipe 2 itself has high rigidity, the diameter of the stylet 1 can be easily reduced. Compared to the above-described conventional stylet, the stylet 1 is more rigid if it has the same outer diameter.

  FIG. 3 shows a part of another stylet 15. This stylet 15 is different from the stylet 1 of FIG. 2 in which the coil spring 10 is fitted on the fitting protrusion 8 in that the coil spring 19 is housed in the fitting hole 18. Parts of the stylet 15 having the same configuration as the stylet 1 in FIG. FIG. 3A shows the stylet 15 in a state where the operation wire 4 is completely loosened and the fitting between the pipes 16 is released. FIG. 3B shows the stylet 15 in a state where the operation wire 4 is pulled and the pipes 16 are fitted to each other.

  A fitting projection 17 is formed at one end of the pipe 16 and a fitting hole 18 is formed at the other end. The fitting protrusion 17 is for fitting with the fitting hole 18 of the adjacent pipe 16. The fitting protrusion 17 is shorter in length than the fitting protrusion 8 of the stylet 1 in FIG. Since the other structure of this fitting protrusion 17 is the same as the fitting protrusion 8 of the stylet 1 of FIG. 2, detailed description is abbreviate | omitted. The fitting hole 18 of the stylet 15 is deeper than the fitting hole 9 of the stylet 1 in FIG. Since the other structure of this fitting hole 18 is the same as the fitting hole 9 of the stylet 1 of FIG. 2, detailed description is abbreviate | omitted.

  As shown in FIG. 3, in the stylet 15, a compression coil spring (hereinafter simply referred to as a coil spring) 19 is housed in the fitting hole 18 in a free state. The operation wire 4 is directly inserted into the inner diameter side of the coil spring 19. The outer diameter of the coil spring 19 when in close contact is smaller than the inner diameter of the fitting hole 18. If the outer diameter of the pipe 16 and the outer diameter of the operation wire 4 are the same as those of the stylet 1 of FIG. 2, the coil spring 19 has an average diameter smaller than that of the coil spring 10 of the stylet 1 of FIG.

  The coil spring 19 has substantially the same free length and substantially the same spring constant as the coil spring 10 of FIG. The depth of the fitting hole 18 is substantially equal to the free length of the coil spring 19. The length of the fitting protrusion 17 is slightly larger than the value obtained by subtracting the contact length of the coil spring 10 from the length of the fitting hole 18. However, it is not limited to these structures.

  This stylet 15 can also provide the same effects (high rigidity, high flexibility, possibility of reducing the diameter, etc.) as the above-described stylet 1 of FIG.

  In the stylet 1 of FIG. 2, the spring constants of all the coil springs 10 are made uniform. Therefore, when the pulling operation force by the operation wire reaches a certain value, all the fitting portions are fitted substantially simultaneously. When the pulling operation force by the operation wire decreases to a certain value, the fitting of all the fitting parts is released substantially simultaneously. The same applies to the stylet 15 in FIG. However, it is not limited to such a configuration. For example, coil springs having a higher spring constant than others may be arranged at some intervals among a plurality of fitting portions at equal intervals. According to such a configuration, when the pulling operation force by the operation wire becomes a certain value, only the fitting portion fitted with the coil spring having the high spring constant is released, and for many other fitting portions. The fitting state is maintained. The curved shape of the stylets 1 and 15 in this state is different from the shape when the fitting of all the fitting portions is released. Moreover, the fitting part which mounts | wears with the said high spring constant coil spring can be selected arbitrarily.

  FIG. 4 shows a part of still another stylet 21. This stylet 21 is different from both the above-described stylets 1 and 15 (FIGS. 2 and 3) in that magnets 25 and 26 are used as elastic members between the pipes 22 instead of coil springs. ing. Parts of the stylet 21 having the same configurations as those of the two stylets 1 and 15 are given the same reference numerals, and the description thereof is omitted. FIG. 4A shows the stylet 21 in a state where the operation wire 4 is completely loosened and the fitting between the pipes 22 is released. FIG. 4B shows the stylet 21 in a state where the operation wire 4 is pulled and the pipes 22 are fitted together.

  A fitting protrusion 23 is formed at one end of the pipe 22 and a fitting hole 24 is formed at the other end. The fitting protrusion 23 is for fitting with the fitting hole 24 of the adjacent pipe 22. An annular first magnet 25 is fixed to one end of the pipe body 27 (the base end of the fitting projection 23) by welding or the like. An annular second magnet 26 is fixed to the other end of the pipe body 27 (the opening end of the fitting hole 24) by welding or the like. The first magnet 25 and the second magnet 26 facing each other in the adjacent pipe 22 are arranged so that the same poles face each other. That is, the first magnet 25 and the second magnet 26 of the adjacent pipe 22 repel each other.

  Since no coil spring is attached to the fitting portion, the length of the fitting protrusion 23 may be equal to the length of the fitting protrusion 8 in FIG. 3, and the depth of the fitting hole 24 is the fitting hole 9 in FIG. It may be equivalent to the depth of. In the stylet 21, the length of the fitting protrusion 23 is larger than the depth of the fitting hole 24 so that the ends of the pipe body 27, that is, the magnets 25 and 26 can come into contact with each other when the operation wire 4 is pulled. It has been slightly shortened. However, it is not limited to such a configuration.

  In the stylet 21, the fitting protrusion 23 is fitted into the fitting hole 24 by the pulling operation of the operation wire 4 that overcomes the repulsive force between the magnets 25 and 26. When the pulling operation of the operation wire 4 is loosened, the fitting is released by the repulsive force between the magnets 25 and 26. This stylet 21 can also provide the same operational effects (high rigidity, high flexibility, possibility of reducing the diameter, etc.) as the above-described stylets 1 and 15 in FIGS.

  FIG. 5 also shows a part of a stylet 31 in which magnets 35 and 36 are used as elastic members. FIG. 5A shows the stylet 31 in a state where the operation wire 4 is completely loosened and the fitting between the pipes 32 is released. FIG. 5B shows the stylet 31 in a state where the operation wire 4 is pulled and the pipes 32 are fitted to each other. This stylet 31 is different from the stylet 21 shown in FIG. 4 in the arrangement positions of the magnets 35 and 36 in the pipe 32. In the stylet 31, an annular third magnet 35 is fixed to the tip of the engaging projection 33 by welding or the like, and an annular fourth magnet 36 is fixed to the inner end of the fitting hole 34 by welding or the like. Yes. Since the other configuration of the stylet 31 is the same as that of the stylet 21 of FIG. 4, the same reference numerals are given to the same components as those of the stylet 21 of FIG.

  In the stylet 21 of FIG. 4, the magnetic forces of all the magnets 25 and 26 are made uniform. Therefore, when the pulling operation force by the operation wire reaches a certain value, all the fitting portions are fitted substantially simultaneously. When the pulling operation force by the operation wire decreases to a certain value, the fitting of all the fitting parts is released substantially simultaneously. The same applies to the stylet 31 in FIG. However, it is not limited to such a configuration. For example, you may arrange | position the magnet of a magnetic force higher than others about several fitting parts at equal intervals among many fitting parts. According to such a configuration, when the pulling operation force by the operation wire becomes a certain value, only the fitting of the fitting portion to which the high magnetic force magnet is attached is released, and many other fitting portions are fitted. The combined state is maintained. The curved shape of the stylets 21 and 31 in this state is different from the shape when the fitting of all the fitting portions is released. Moreover, the fitting part which mounts | wears with the said high magnetic force magnet can be selected arbitrarily.

  Although not shown, the tip end portions of the fitting protrusions 8, 17, 23, and 33 of the above-described stylets 1, 15, 21, and 31 may be formed in a tapered shape with a diameter reduced toward the tip. Moreover, the opening end part of each fitting hole 9, 18, 24, 34 of the above-mentioned stylet 1, 15, 21, and 31 may be formed in the taper shape which expanded the diameter toward the opening end. According to such a configuration, the fitting projection and the fitting hole can be more easily fitted and released.

  The stylet according to the present invention is useful for adjusting the flexibility of an endoscope.

DESCRIPTION OF SYMBOLS 1, 15, 21, 31 ... Stylet 2, 16, 22, 32 ... Pipe 3 ... Through-hole 4 ... Operation wire 5 ... Pipe stopper 6 ... Operation part 7, 27 ... Pipe body 8, 17, 23, 33 ... Fitting protrusions 9, 18, 24, 34 ... Fitting holes 10, 19 ... Coil springs 11 ... Steps 25, 26, 35 36 A magnet A pulling operation direction

Claims (4)

A stylet that adjusts the flexibility of the insertion portion of the endoscope while being inserted through the forceps hole of the endoscope,
A plurality of tubular elements each having a through hole;
A linear member for operation inserted through the through holes of the plurality of tubular elements;
A resilient member disposed at the end of the tubular element and capable of resiliently separating adjacent tubular elements;
Each tubular element has a fitting portion that can be fitted with an adjacent tubular element;
A stylet configured such that the tubular members can be fitted to each other with the elastic member interposed by pulling the linear member. The fitting part is
A fitting hole formed in the longitudinal direction at one end of the tubular element;
The stylet according to claim 1, further comprising a fitting protrusion that is provided in a projecting manner in the longitudinal direction at the other end of the tubular element and can be fitted into the fitting hole . The elastic member is
Coil spring may be mounted within the fitting hole while fitted on the linear member, or,
The stylet according to claim 2, wherein the stylet is a coil spring that can be mounted in a state of being externally fitted to the fitting protrusion. The elastic member is
A magnet attached to the back end of the fitting hole and the tip of the fitting projection so as to be repelled with each other, or
The stylet according to claim 2, wherein the stylet is a magnet that is attached to a front end opening of the fitting hole and a base end of the fitting projection so as to be repelled from each other.

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