Soft endoscope

Abstract

Provided is a soft endoscope of a new structure which enables single use by reducing the number of parts and simplifying the structure, and makes it possible to reduce the burden of washing and sterilization before reuse.　The soft endoscope 10 comprises: a shaft 12 which has lumens 18, 20 that penetrate in a length direction; a distal end chip 14 which is provided in a distal end side of the shaft 12; an imaging device 42 which acquires an image of the distal end side; a light source 44 which projects light towards the distal end side; electric wiring 22 which extends into the lumen 18 of the shaft 12 and is connected to the imaging device 42 and the light source 44; a curved movable unit 28 which is provided at a distal end portion of the shaft 12 and for which bending deformation is allowed; and an operation wire 34 which extends into the lumen 20 of the shaft 12, is fixed at the distal end of the curved movable unit 28, and makes it possible to control bending deformation of the curved movable unit 28 by means of an external operation force, wherein the entirety of the curved movable unit 28 does not have a frame structure, is configured with a soft flexible tube, and is limited to a single use.

Description

Flexible endoscope

[0001] The present invention relates to a flexible endoscope having a tip portion that can be bent and deformed.

[0002] Flexible endoscopes with bendable distal ends have been known as a type of endoscope used for percutaneously observing and treating lesions within the body. The bendable distal end of a flexible endoscope allows it to control the orientation of an imaging device or light source provided at the distal tip, and to control the protrusion direction of a treatment tool such as forceps. Japanese Patent Laid-Open Publication No. 2010-259478 (Patent Document 1) discloses a flexible endoscope whose distal end has a skeletal structure in which a plurality of annular joint members are connected, and which is capable of tilting relative to one another, thereby allowing the distal end to be bent and deformed.

[0003] JP 2010-259478 A

[0004] Flexible endoscopes are cleaned and sterilized after use before being reused, but thorough cleaning and sterilization are required to prevent infection when reused, and the cleaning and sterilization process is cumbersome.Furthermore, flexible endoscopes are sterilized using strong acidic chemicals, which can easily cause problems with deterioration of the flexible endoscope due to these chemicals.

[0005] Furthermore, the flexible endoscope described in Patent Document 1 employs a skeletal structure to ensure durability and stable bending characteristics when reused, which results in a large number of parts and a complex structure, which inevitably leads to high costs.

[0006] An object of the present invention is to provide a flexible endoscope with a novel structure that can solve the above-mentioned problems of conventional flexible endoscopes.

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] In a first aspect, the flexible endoscope comprises a hollow shaft having a lumen passing through in the lengthwise direction, a distal tip provided at the distal end of the shaft, an imaging device provided at the distal tip for capturing an image of the distal end, a light source provided at the distal tip for projecting light toward the distal end, electrical wiring extending within the lumen of the shaft and connected to the imaging device and the light source, a bending movable section provided at the distal end of the shaft and allowed to bend, and an operating wire extending within the lumen of the shaft and fixed to the distal end of the bending movable section, enabling the bending deformation of the bending movable section to be controlled by an external operating force, the entire bending movable section being made of a soft flexible tube without a skeletal structure, and being limited to single use.

[0009] In a flexible endoscope constructed according to this aspect, the entire bending movable section is constructed of a soft flexible tube without a skeletal structure, which allows for the bending deformation of the tip section required in a flexible endoscope while reducing the number of parts and simplifying the structure. This makes it possible to make the flexible endoscope a single-use device, minimizing the risk of infection and eliminating the need for cleaning and sterilization after use, thereby saving busy medical professionals the trouble of using it.

[0010] In a second aspect, in the flexible endoscope described in the first aspect, the shaft has the bending movable portion and a shaft main body that is located on the base end side of the bending movable portion, and the bending movable portion has a bending rigidity that is smaller than that of the shaft main body.

[0011] In a flexible endoscope constructed according to this aspect, the bending rigidity of the bending movable portion is reduced, making it easier to bend. Also, the bending rigidity of the shaft main body is greater than that of the bending movable portion, making the shaft main body less likely to bend than the bending movable portion, preventing the external operating force applied to the operating wire from the base end side from being difficult to transmit to the bending movable portion due to bending deformation of the shaft main body, and allowing the bending movable portion to be bent efficiently.

[0012] In a third aspect, in the flexible endoscope described in the first or second aspect, the shaft has the bending movable portion and a shaft main body located on the base end side of the bending movable portion, and is provided with a deformation restriction mechanism that limits the amount of bending deformation of the shaft main body when an external operating force acts on the operating wire.

[0013] With a flexible endoscope constructed in accordance with this aspect, the amount of bending deformation of the shaft body is limited by the deformation restriction mechanism, so that the external operating force applied to the operating wire is efficiently transmitted to the bending movable section that is closer to the tip than the shaft body, allowing the bending movable section to bend and deform sufficiently greatly.

[0014] In a fourth aspect, in the flexible endoscope described in the third aspect, the operating wire fixed to a portion of the circumferential direction of the bending movable portion is branched into multiple branches on the base end side, and the multiple branched operating wires are arranged at equal intervals in the circumferential direction of the shaft body.

[0015] In a flexible endoscope constructed according to this aspect, an external manipulation force applied to the manipulation wire is applied to a portion of the bending movable portion in the circumferential direction, causing bending deformation of the bending movable portion. On the other hand, on the proximal side of the bending movable portion, the manipulation wire branches into multiple branches that are arranged at equal intervals in the circumferential direction of the shaft main body, so that the external manipulation forces acting on the branched portions of the manipulation wire cancel each other out, thereby suppressing bending deformation of the shaft main body due to the external manipulation force. As a result, the external manipulation force applied to the manipulation wire is efficiently applied to the bending movable portion, allowing efficient bending deformation of the bending movable portion.

[0016] In a fifth aspect, in the flexible endoscope described in the third aspect, the operating wire is inserted into a coil spring in the shaft body, and the deformation restriction mechanism is formed by the coil spring that contracts as the operating wire is pulled.

[0017] In a flexible endoscope constructed according to this aspect, when the manipulation wire is pulled toward the proximal end to bend the bending movable section, the bending deformation of the shaft main body on the proximal end side of the bending movable section is suppressed by the coil spring, which has contracted and has increased bending rigidity, and therefore the external manipulation force (tensile force) applied to the manipulation wire is efficiently transmitted to the bending movable section. For example, when the coil spring is not significantly compressed by the external manipulation force of the manipulation wire, the gaps between the windings allow bending deformation, which prevents the shaft main body from becoming difficult to insert into a body lumen due to insertion of the coil spring.

[0018] In a sixth aspect, in the flexible endoscope described in any one of the first to fifth aspects, the lumen of the shaft comprises a main lumen and a plurality of sub-lumens arranged around the main lumen, the electrical wiring is inserted through the main lumen, and the operating wire is inserted through the sub-lumens.

[0019] In a flexible endoscope constructed in accordance with this aspect, the lumen through which the electrical wiring is inserted and the lumen through which the operating wire is inserted are provided independently of each other, thereby preventing contact between the electrical wiring and the operating wire within the lumen.

[0020] In a seventh aspect, in the flexible endoscope described in the sixth aspect, the plurality of sub-lumens are arranged evenly in the circumferential direction, and the plurality of sub-lumens include a wire insertion lumen through which the operating wire is inserted and a molding lumen through which the operating wire is not inserted.

[0021] In a flexible endoscope constructed according to this aspect, the sub-lumens include molding lumens through which no operating wires are inserted, making it easy to arrange multiple sub-lumens evenly and close to each other in the circumferential direction, thereby providing greater freedom in the placement of operating wires and preventing distortion of the shaft due to thermal shrinkage after molding.

[0022] In an eighth aspect, in the flexible endoscope according to any one of the first to seventh aspects, the maximum bending angle of the bending movable portion is set to 270 degrees or more.

[0023] With a flexible endoscope constructed according to this aspect, a large maximum bending angle of the bending movable part is ensured, and the bending angle required for the tip portion of the flexible endoscope can be achieved by the bending movable part made of a flexible tube.

[0024] A ninth aspect is a flexible endoscope according to any one of the first to eighth aspects, wherein the bending movable portion can be bent and deformed in any radial direction by operating the plurality of operating wires.

[0025] With a flexible endoscope constructed according to this aspect, by manipulating the multiple control wires, it is possible to obtain a large degree of freedom in the direction in which the bending deformation section is allowed to bend, which can improve, for example, the ease of inserting the bending deformation section into a body lumen, and by appropriately setting the direction of the tip of the flexible endoscope, it is possible to achieve more efficient observation and treatment inside a body lumen.

[0026] According to the present invention, the number of parts is reduced and the structure is simplified, allowing for single-use, and eliminating the need for cleaning and sterilization before reuse.

[0027] 1. A front view showing a flexible endoscope as a first embodiment of the present invention. 2. A plan view of the flexible endoscope shown in FIG. 1. 3. An enlarged view of the III-III cross section of FIG. 1. 4. An enlarged view of the IV-IV cross section of FIG. 1. 5. A perspective view of the tip portion of the flexible endoscope shown in FIG. 1. 6. A photograph showing the maximum bending deformation state of the bending movable part of the flexible endoscope shown in FIG. 1. 7. A left side view of the flexible endoscope as an enlargement. 8. A VIII-VIII cross section of FIG. 7. A cross section of the handpiece constituting the flexible endoscope shown in FIG. 1, which corresponds to the IX-IX cross section of FIG. 1. 9. A longitudinal cross section showing a part of the shaft of a flexible endoscope as a second embodiment of the present invention.

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0029] 1 and 2 show a flexible endoscope 10 as a first embodiment of the present invention. The flexible endoscope 10 has a structure in which a distal tip 14 is attached to the distal end of a shaft 12 and a handpiece 16 is attached to the proximal end of the shaft 12. In the following description, the distal end generally refers to the distal end when in use, and the proximal end generally refers to the proximal end when in use.

[0030] As shown in Figures 3 and 4, the shaft 12 is a hollow tube having a main lumen 18 with a circular cross section that passes through the center. The shaft 12 also has a plurality of sub-lumens 20 that pass through the peripheral wall of the main lumen 18 in a direction substantially parallel to the main lumen 18. The lumen of the shaft 12 in this embodiment is composed of one main lumen 18 and twelve sub-lumens 20, 20, ..., 20. The main lumen 18 has a larger diameter than the sub-lumens 20, and electrical wiring 22 and a channel tube 24 are inserted therein. The sub-lumens 20 are arranged approximately evenly in the circumferential direction around the main lumen 18. The circumferential arrangement of the plurality of sub-lumens 20 is not limited to being strictly even, and some deviation in the circumferential direction is acceptable.

[0031] The thickness of the shaft 12 is set appropriately depending on the body lumen into which it will be inserted during use, but is preferably 2.0 mm or greater, for example. This ensures that the distal end portion (distal tip 14) of the flexible endoscope 10 has sufficient space for arranging an imaging device 42 and a light source 44, which will be described later, and for forming a through-hole 48, which will be described later. Note that a thicker shaft 12 may be used when, for example, a high-performance imaging device 42 is required. However, taking into consideration the bending and deformation performance of the shaft 12 and the thickness of the body lumen, it is preferable that the thickness of the shaft 12 be 10 mm or less.

[0032] The shaft 12 includes a shaft body 26. The shaft body 26 constitutes the proximal end portion of the shaft 12, including the portion connecting to the handpiece 16, and has a length of, for example, more than half of the entire shaft 12. The shaft body 26 is formed from a resin material such as nylon or polyamide such as aramid, and has a degree of flexibility that allows the flexible endoscope 10 to be inserted into a curved body lumen. The shaft body 26 may be reinforced, for example, with a braid made of metal wire.

[0033] A bending movable section 28 that is allowed to bend is provided at the distal end of the shaft body 26. The bending movable section 28 is composed of a tube that is independent of the shaft body 26 in the axial direction and has lower bending rigidity than the shaft body 26, allowing it to bend with a smaller bending moment. As shown in FIG. 3 , the bending movable section 28 does not have an internal skeletal structure and is entirely composed of a soft, flexible tube. That is, the bending movable section 28 of this embodiment has a structure in which a flexible covering tube 32 is provided to cover the outer surface of a flexible soft tube 30, and is entirely soft and flexible. In addition, the electrical wiring 22 and the channel tube 24 are inserted into the main lumen 18 of the bending movable section 28, and these electrical wiring 22 and the channel tube 24 are also flexible, allowing bending deformation of the bending movable section 28. Furthermore, a manipulation wire 34 (described later) is inserted through the sub-lumen 20 of the bending movable portion 28, and the manipulation wire 34 is also flexible and allows bending deformation of the bending movable portion 28. The materials forming the soft tube 30 and the covering tube 32 constituting the bending movable portion 28 are not particularly limited and may be the same or different. Materials that are harmless to the human body and have excellent stretchability and flexibility are desirable as materials for forming the soft tube 30 and the covering tube 32; for example, resin materials such as expanded polytetrafluoroethylene (ePTFE) and polyurethane are preferably used. The above-mentioned skeletal structure is a structure in which soft node members are connected in a manner that allows them to tilt relative to each other, as shown in, for example, JP 2010-259478 A, and each node member is harder than the soft tube 30.

[0034] A plate 33 is fixed to the distal end surface of the bending movable portion 28. The plate 33 is a hard member made of synthetic resin, metal, or the like, and has a generally annular plate shape overall. The plate 33 has a central hole in its center corresponding to the main lumen 18, and a plurality of peripheral holes around the central hole corresponding to the sub-lumens 20. The central hole of the plate 33 forms the distal end of the main lumen 18, and the peripheral holes of the plate 33 form the distal end of the sub-lumen 20.

[0035] An operation wire 34 is inserted through the sub-lumen 20 of the shaft 12. The operation wire 34 is made of a metal material such as medical stainless steel, and may be a single wire or a stranded wire made by twisting together multiple wires. As shown in Figure 5, the operation wire 34 extending within the sub-lumen 20 of the shaft 12 is folded back at the distal end of the shaft 12, and the folded back portion is fixed to a plate 33 provided at the distal end of the bending movable section 28. Furthermore, by folding back the operation wire 34 at the distal end, the proximal end side is branched into two.

[0036] In this embodiment, four operating wires 34a, 34b, 34c, and 34d are arranged. To facilitate understanding of the arrangement of the operating wires 34a, 34b, 34c, and 34d, the branched portions of the operating wires 34a, 34b, 34c, and 34d are denoted by reference numerals 34a', 34b', 34c', and 34d' in Figures 3 and 4, respectively.

[0037] As shown in FIG. 3 , the branched portions 34′, 34′ of the operation wire 34 are inserted into the circumferentially adjacent sub-lumens 20, 20 at their distal end portions, which are portions that pass through the bending movable portion 28, and are disposed substantially in a portion of the circumferential direction of the bending movable portion 28. The distal end portion of the operation wire 34a is attached to the distal end portion of the bending movable portion 28 in a portion of the circumferential direction of the bending movable portion 28, so that when the branched portions 34a′, 34a′ of the operation wire 34a are pulled toward the base end, the bending movable portion 28 is bent in one radial direction to which the operation wire 34a is attached. Similarly, the operation wires 34b, 34c, 34d are attached to a portion of the circumferential direction of the distal end portion of the bending movable portion 28, so that by pulling these operation wires 34b, 34c, 34d, the bending movable portion 28 can be bent in the corresponding radial direction.

[0038] In this embodiment, the attachment positions of the four operation wires 34a, 34b, 34c, and 34d to the bending movable portion 28 are arranged approximately evenly in the circumferential direction. Therefore, by selectively pulling the operation wires 34a, 34b, 34c, and 34d, the bending movable portion 28 can be bent in four radial directions (up / down and left / right directions in FIG. 3 ) that are shifted by 90 degrees in the circumferential direction. Furthermore, by pulling the operation wires 34a, 34b, 34c, and 34d in combination, the bending movable portion 28 can be bent in any radial direction within 360 degrees. Therefore, by adjusting the force (external operation force) applied to each of the four operation wires 34a, 34b, 34c, and 34d, the direction and bending angle of bending deformation of the bending movable portion 28 can be controlled.

[0039] As shown in FIG. 4 , the branched portions 34′, 34′ of the operation wire 34 are arranged at approximately equal intervals around the circumferential direction of the shaft body 26 on the proximal end side, which is the portion where the operation wire 34 is inserted into the shaft body 26, and are located on both radial sides of the main lumen 18. When the operation wire 34a is pulled, an external operation force (tensile force) acting on the branched portions 34a′, 34a′ of the operation wire 34a is canceled out in the shaft body 26 because the insertion portions of the branched portions 34a′, 34a′ into the shaft body 26 are located on both radial sides of the shaft body 26. Therefore, when the operation wire 34a is pulled to bend the bending movable portion 28, the shaft body 26 is less likely to bend. As a result, the external operation force acting on the operation wire 34a is transmitted to the bending movable portion 28 without being significantly reduced by bending the shaft body 26, and the bending movable portion 28 is efficiently bent in response to an operation, such as pulling the operation wire 34a. As with the operating wire 34a, the portions of the operating wires 34b, 34c, and 34d that are inserted into the shaft body 26 are arranged on both radial sides of the shaft body 26, so that when an external operating force is applied to the operating wires 34b, 34c, and 34d, bending deformation of the shaft body 26 is unlikely to occur, and bending deformation of the curved movable portion 28 occurs efficiently.

[0040] In this way, the base end side of the operation wire 34 has two branched portions 34', 34', and the branched portions 34', 34' are arranged at equal intervals in the circumferential direction of the shaft body 26, thereby forming a deformation restriction mechanism that restricts bending deformation of the shaft body 26. In short, the deformation restriction mechanism of this embodiment is realized by the arrangement of the operation wire 34.

[0041] In the present embodiment, the bending rigidity of the bending movable portion 28 of the shaft 12 is smaller than the bending rigidity of the shaft body 26, making the bending movable portion 28 easier to bend than the shaft body 26. This also suppresses the escape of external operating forces due to bending deformation of the shaft body 26, thereby realizing efficient bending deformation of the bending movable portion 28.

[0042] As shown in FIG. 6, the bending movable portion 28 of this embodiment has a maximum bending angle α of 270 degrees or more.

[0043] 3 and 4, the shaft 12 of this embodiment has twelve sub-lumens 20 formed around the main lumen 18, with eight of the sub-lumens 20 serving as wire insertion lumens through which the operation wires 34a, 34b, 34c, and 34d are inserted, and the remaining four sub-lumens 20 serving as molding lumens through which no operation wires 34 are inserted. By forming more sub-lumens 20 in the shaft 12 than the number of operation wires 34 inserted in this way, it is possible to evenly arrange the multiple sub-lumens 20 in the circumferential direction while reducing the circumferential distance between adjacent sub-lumens 20, 20 in the circumferential direction.

[0044] For example, when a shaft 12 having a plurality of sub-lumens 20 around the main lumen 18 is molded by extrusion molding, the molded shaft 12 is deformed by cooling contraction, but if the plurality of sub-lumens 20 are not evenly arranged in the circumferential direction, stress may vary in the circumferential direction, causing the shaft 12 to deform into a distorted cross-sectional shape. Therefore, by including a molding lumen in the sub-lumen 20 through which the operating wire 34 is not inserted, and by evenly arranging the sub-lumens 20 while shortening the circumferential distance between the sub-lumens 20, stress in the shaft 12 due to cooling contraction can be made uniform, and distorted deformation of the shaft 12 can be prevented.

[0045] By arranging the multiple sub-lumens 20 close to each other in the circumferential direction, the branched portions 34a', 34a' of the operation wire 34a inserted into circumferentially adjacent sub-lumens 20, 20 in the bending movable portion 28 are attached at positions close to each other in the circumferential direction with respect to the tip portion of the bending movable portion 28. As a result, by operating the operation wire 34a, an external operating force can be concentrated on one part of the circumferential direction with respect to the bending movable portion 28, thereby efficiently causing bending deformation in one radial direction of the bending movable portion 28. Similarly, it is easy to set the attachment positions of the operation wires 34b, 34c, 34d to the bending movable portion 28 within a narrow circumferential range, allowing efficient bending deformation of the bending movable portion 28.

[0046] A distal tip 14 is attached to the distal end of the shaft 12. As shown in Figures 5, 7, and 8, the distal tip 14 has a generally cylindrical shape with a bottom as a whole, and is attached to the shaft 12 so as to cover the distal openings of the main lumen 18 and the sub-lumen 20 by having a peripheral wall portion 38 fixed to the distal end of the bending movable portion 28. The attachment structure of the distal tip 14 to the shaft 12 is not particularly limited. For example, the covering tube 32 at the distal end of the bending movable portion 28 may be removed, and the peripheral wall portion 38 of the distal tip 14 may be fixed by means of thermal welding or the like while being fitted over the soft tube 30 and plate 33 of the bending movable portion 28, thereby joining the distal tip 14 and the bending movable portion 28. Note that in Figure 5, the peripheral wall portion 38 and bottom wall portion 40 of the distal tip 14 are shown translucent to facilitate understanding of the internal structure of the distal tip 14.

[0047] An imaging device 42 is attached to the bottom wall 40 of the distal tip 14. The imaging device 42 has, for example, an optical system consisting of lenses and an imaging element such as a CCD or CMOS. The imaging device 42 captures an image of the distal end of the flexible endoscope 10, and the image captured by the imaging device 42 is displayed on an external monitor (not shown) via the electrical wiring 22.

[0048] Light sources 44 are disposed on both the left and right outer sides of the imaging device 42 on the bottom wall 40 of the distal tip 14. The light sources 44 are, for example, light-emitting diodes (LEDs) that project light toward the distal end of the flexible endoscope 10. This allows the distal end of the flexible endoscope 10 inserted into a body lumen to be illuminated by the light sources 44 while being photographed by the imaging device 42, making it possible to visually confirm the state of the body lumen on a monitor. The arrangement of the imaging device 42 and the light sources 44, 44 on the distal tip 14 is not particularly limited. The number of light sources 44 does not necessarily have to be two, and may be one, or three or more. However, by disposing two light sources 44, 44 on both sides of the imaging device 42, shadows are less likely to appear in the images even with a small number of light sources 44.

[0049] An electrical wiring 22 is connected to the imaging device 42 and the light sources 44, 44. The electrical wiring 22 is a coated electric wire in which a conductive core wire is covered with an electrically insulating coating, and the core wire exposed at the tip is connected to an electrical fitting 46 disposed inside the distal tip 14, and the electrical fitting 46 is connected to the imaging device 42 and the light sources 44, 44. Electric power is supplied from an external power source to the imaging device 42 and the light sources 44, 44 through the electrical wiring 22, and image data acquired by the imaging device 42 is transmitted to an external monitor through the electrical wiring 22. The electrical wiring 22 is inserted into the main lumen 18 of the shaft 12 and extends toward the proximal end.

[0050] It is also possible to capture images of the distal end side of the flexible endoscope 10 and project light onto the distal end side using a structure that uses, for example, an optical fiber, but in that case, it is conceivable that the optical fiber inserted into the shaft 12 will limit the amount of bending deformation that the shaft 12 can tolerate. Therefore, if an imaging device 42 using an imaging element such as a CCD or CMOS and a light source 44 consisting of an LED or the like are used as in this embodiment, flexible electrical wiring 22 connecting the imaging device 42 and the light source 44 is inserted into the shaft 12, and therefore limitations on the amount of bending deformation of the shaft 12 due to the wiring between the imaging device 42 and the light source 44 are less likely to be a problem.

[0051] A through-hole 48 into which the distal end of the channel tube 24 is inserted is provided in the bottom wall 40 of the distal tip 14. The distal opening of the channel tube 24 is open toward the distal end through the through-hole 48 of the distal tip 14, allowing a treatment tool (not shown) such as forceps inserted into the channel tube 24 to protrude distally beyond the flexible endoscope 10. This makes it possible to perform treatment or the like using the treatment tool at the distal end of the flexible endoscope 10 while viewing images from the imaging device 42.

[0052] A handpiece 16 is disposed on the proximal end side of the shaft 12. As shown in Figure 9, the handpiece 16 includes a housing 50 to which the proximal end portion of the shaft 12 is attached, and a first operating handle 52 and a second operating handle 54 that are rotatable relative to the housing 50.

[0053] The housing 50 has a hollow structure with an internal space 58, which is in communication with the main lumen 18 and sub-lumen 20 of the shaft 12. The housing 50 is tapered so that its width in the left-right direction decreases toward its distal end, and its height in the up-down direction is generally constant. A shaft mounting hole 60 is formed in the housing 50, penetrating the distal end, and the proximal end of the shaft body 26 is inserted and fixed into this shaft mounting hole 60. The electrical wiring 22 and the channel tube 24 are introduced into the housing 50 through the shaft mounting hole 60. A kink-resistant tube 61 is provided in an externally inserted state on the portion of the shaft body 26 extending from the housing 50 to the outside, reinforcing the portion of the shaft body 26 attached to the housing 50 and making it less likely to bend.

[0054] The internal space 58 of the housing 50 accommodates the operating wire 34, which is inserted through the shaft 12, the channel tube 24, and the electrical wiring 22. The operating wire 34 is attached to either a first rotation shaft 64 (described later) of the first operating handle 52 or a second rotation shaft 66 (described later) of the second operating handle 54 in the internal space 58. Although not necessarily shown in the drawings, the internal space 58 is open to the outside at the base end, and the channel tube 24 and the electrical wiring 22 extend from the housing 50 to the outside at the base end. Specifically, for example, the internal space 58 is open to the outside through a kink-resistant tube 62 provided at the base end, and the electrical wiring 22 extends from the housing 50 to the outside through the kink-resistant tube 62, and the electrical wiring 22 is connected to an external power source, monitor, or the like.

[0055] The first operating handle 52 and the second operating handle 54 are provided to protrude from the side of the housing 50 (upward in FIG. 9 ). A cylindrical first rotating shaft 64 extending from the first operating handle 52 is inserted into a cylindrical second rotating shaft 66 extending from the second operating handle 54. The first rotating shaft 64 passes through the housing 50 and is attached so as to be rotatable relative to the housing 50, and the second rotating shaft 66 is allowed to rotate relative to the housing 50 and the first rotating shaft 64, with the first rotating shaft 64 serving as the rotation center axis. The first operating handle 52 and the first rotating shaft 64, and the second operating handle 54 and the second rotating shaft 66 may be formed separately and fixed to each other with bolts or the like, or may be formed integrally.

[0056] The operation wires 34a and 34c are attached to the first rotation shaft 64 of the first operation handle 52. Rotating the first operation handle 52 in one direction pulls the operation wire 34a toward the proximal end, and rotating the first operation handle 52 in the other direction pulls the operation wire 34c toward the proximal end. The operation wires 34b and 34d are attached to the second rotation shaft 66 of the second operation handle 54. Rotating the second operation handle 54 in one direction pulls the operation wire 34b toward the proximal end, and rotating the second operation handle 54 in the other direction pulls the operation wire 34d toward the proximal end. Therefore, rotating the first operation handle 52 can bend the curved movable portion 28 of the shaft 12 in the up-down direction, and rotating the second operation handle 54 can bend the curved movable portion 28 of the shaft 12 in the left-right direction.

[0057] Furthermore, by rotating both the first operating handle 52 and the second operating handle 54, the bending movable section 28 can be bent in an oblique direction inclined relative to the up-down and left-right directions. Therefore, by operating the multiple operating wires 34 with the first operating handle 52 and the second operating handle 54 and adjusting the amount of rotation of the first operating handle 52 and the amount of rotation of the second operating handle 54, i.e., the external operating forces applied to the multiple operating wires 34, the bending movable section 28 can be bent in any radial direction. In this embodiment, the first operating handle 52 and the second operating handle 54 are arranged on approximately the same central axis, and the operating portions are arranged overlapping each other, making it easy to operate them simultaneously.

[0058] Furthermore, because the first operating handle 52 and the second operating handle 54 have different maximum outer diameters, selective operation of the first operating handle 52 and the second operating handle 54 can be easily performed even when the first operating handle 52 and the second operating handle 54 are arranged overlapping each other. The first operating handle 52 and the second operating handle 54 are each substantially rectangular, with the outer peripheral surfaces of the four corners being flat or arc-shaped curved surfaces curved in the circumferential direction. The first operating handle 52 and the second operating handle 54 have different outer peripheral surface shapes at the four corners, and the first operating handle 52 and the second operating handle 54 have corresponding shapes. This makes it possible to easily grasp the amount of rotation of the first operating handle 52 and the second operating handle 54 by visual inspection or touch. In this embodiment, the difference in the outer peripheral surface shapes of the four corners is set by varying the number of notches formed on the outer peripheral surfaces of the four corners of the first operating handle 52 and the second operating handle 54, each of which has a different number ranging from 0 to 3. Note that the structure that enables confirmation of the amount of rotation of the first operating handle 52 and the second operating handle 54 is not limited to the notches described above, and for example, markings that indicate the amount of rotation of the operating handles 52, 54 may be applied to the surfaces of the operating handles 52, 54 so that they can be ascertained.

[0059] The flexible endoscope 10 of this embodiment having such a structure is used, for example, when performing various examinations and treatments in internal body lumens. The flexible endoscope 10 is suitably used, for example, as a ureter-nephroscope, gastroscope, pharyngoscope, bronchoscope, etc., and is particularly suitably employed as a ureter-nephroscope which requires a large bending deformation angle at the tip portion.

[0060] The shaft 12 is inserted into a lumen in the patient's body through an incision in the patient's skin, and the practitioner can bend and deform the bending movable portion 28 in any radial direction by rotating the first and second operating handles 52, 54 of the handpiece 16. This makes it possible to change the orientation of the distal tip 14, allowing the shaft 12 to follow the curvature of the lumen in the body, making it easier to insert the shaft 12 to the area requiring treatment or examination. In addition, the imaging direction of the imaging device 42 can be changed to observe the state inside the lumen in the body.

[0061] The shaft 12 has a multi-lumen structure provided with a plurality of sub-lumens 20 that are independent of the main lumen 18 and are arranged around the main lumen 18, and the electrical wiring 22 and the channel tube 24 are inserted into the main lumen 18, while the operating wire 34 is inserted into the sub-lumen 20 of the shaft 12. As a result, when the first and second operating handles 52, 54 are rotated to apply an external operating force to the operating wire 34, the operating wire 34 does not come into contact with the electrical wiring 22 and the channel tube 24, and damage due to contact can be avoided.

[0062] In the flexible endoscope 10, the arrangement of the operating wires 34a, 34b, 34c, and 34d reduces the amount of bending deformation of the shaft body 26 and sets a large maximum bending angle for the bending movable section 28. Furthermore, the bending rigidity of the bending movable section 28 is set lower than that of the shaft body 26, thereby reducing the amount of bending deformation of the shaft body 26 and increasing the maximum bending angle of the bending movable section 28. Specifically, for example, in this embodiment, as shown in FIG. 6 , the maximum bending angle α of the bending movable section 28 is set to a large value of 270 degrees or greater. This large maximum bending angle α of the bending movable section 28 provides a large degree of freedom in bending deformation of the bending movable section 28, enabling it to follow the curvatures of various body lumens. In particular, the large degree of freedom of deformation of the bending movable section 28 and the ability to control the bending deformation with a relatively simple operation make it relatively easy to access areas that are difficult to observe with a flexible endoscope, such as the renal calyx.

[0063] The flexible endoscope 10 is limited to single use. That is, the flexible endoscope 10 is washed and sterilized after use and is not reused, but is discarded after a single use. Such single-use limitation is realized, for example, by indicating on the packaging material of the flexible endoscope 10 or the handpiece 16 of the flexible endoscope 10 that it should be discarded after a single use and that reuse is prohibited.

[0064] By limiting the flexible endoscope 10 to single-use applications, cleaning and sterilization after use are no longer necessary, significantly reducing the workload of medical personnel. Moreover, the risk of infection caused by reusing a flexible endoscope is completely avoided, providing excellent safety.

[0065] Furthermore, the flexible endoscope 10 has a bending movable section 28 entirely made of a flexible tube, and does not have a skeletal structure with many connected joint members like conventional flexible endoscopes, so it has a simple structure with a small number of components, making it possible to realize single-use low-cost, etc. Furthermore, because the flexible endoscope 10 does not undergo cleaning or sterilization for reuse, it is not subject to deterioration due to contact with chemical solutions used for cleaning or sterilization, and there is a great degree of freedom in selecting materials for its construction without considering resistance to those chemical solutions, making it easy to select materials that can achieve required performance, such as excellent bending characteristics and low cost.

[0066] 10 and 11 show a flexible endoscope 70 as a second embodiment equipped with a deformation restriction mechanism of another type. The deformation restriction mechanism of the flexible endoscope 70 is composed of a coil spring 74 inserted around an operating wire 72.

[0067] More specifically, the flexible endoscope 70 of this embodiment is provided with a manipulation wire 72 that is not folded back at the tip of the shaft 12 and extends entirely without branching. Furthermore, unlike the first embodiment, the single manipulation wire 72 is inserted through sub-lumens 20 at different circumferential positions in the bending movable section 28 and the shaft main body 26, but is instead inserted through sub-lumens 20 that are arranged in series along the length of the shaft 12. In this embodiment, the bending movable section 28 and the shaft main body 26 are arranged continuously in the axial direction, and one manipulation wire 72 is inserted through one sub-lumen 20 that is continuous along the length of the shaft 12. In this embodiment, four sub-lumens 20 are arranged at equal intervals in the circumferential direction, and one manipulation wire 72a, 72b, 72c, 72d is inserted through each of the four sub-lumens 20. The operation wires 72a, 72b, 72c, and 72d inserted into the sub-lumen 20 have their distal ends fixed to the distal end of the bending movable portion 28 by welding or other means.

[0068] The portion of the operation wire 72 disposed on the shaft main body 26 is inserted through a coil spring 74. The coil spring 74 has an outer diameter that allows it to be inserted through the sub-lumen 20 and an inner diameter that allows the operation wire 72 to be inserted through it. As shown in FIG. 10 , the coil spring 74 is inserted through the sub-lumen 20 of the shaft main body 26 while being inserted around the operation wire 72. When no external force is applied in the compressive direction or when an external force acting in the compressive direction is small, the coil spring 74 is allowed to bend due to gaps between the windings. Furthermore, when the coil spring 74 is compressed in the axial direction with a sufficiently large force, the gaps between the windings become small or disappear, thereby limiting the bending deformation. For example, the distal end of the coil spring 74 is fixed to the operation wire 72, and the proximal end position is determined by a handpiece (not shown) or the like, so that the coil spring 74 is compressed in the axial direction when the operation wire 72 is pulled toward the proximal end.

[0069] With the flexible endoscope 70 according to this embodiment, when the operation wire 72 is pulled to bend the bending movable portion 28, the bending movable portion 28 can be bent to a large bending deformation angle. That is, when the operation wire 72 is pulled to bend the bending movable portion 28, the coil spring 74, the distal end of which is fixed to the operation wire 72, is compressed in the axial direction as the operation wire 72 moves toward the proximal end. The axially compressed coil spring 74 has its inter-winding gaps sufficiently reduced or eliminated, thereby limiting its bending deformation. The bending deformation of the shaft main body 26, through which the coil spring 74 is inserted into the sub-lumen 20, is restricted by the coil spring 74. This deformation restriction mechanism, formed by the coil spring 74 contracting as the operation wire 72 is pulled, prevents the external operating force from escaping due to bending deformation of the shaft main body 26, and the external operating force is efficiently transmitted to the bending movable portion 28, thereby efficiently causing bending deformation of the bending movable portion 28.

[0070] In order to efficiently obtain a large bending deformation angle of the bending movable portion 28, it is desirable to provide a deformation restriction mechanism that limits the bending deformation of the shaft main body 26, but a deformation restriction mechanism is not essential in a flexible endoscope.

[0071] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific descriptions. For example, in the first embodiment, the proximal end portion of the operation wire 34 is branched by folding back the operation wire 34 at the distal end, but the proximal end portion of the operation wire 34 can also be branched into multiple parts by dividing the proximal end portion of the operation wire 34 into multiple parts. Note that the proximal end portion of the operation wire 34 may be branched into three or more parts.

[0072] In the above embodiment, a shaft 12 with a multi-lumen structure having a main lumen 18 and a sub-lumen 20 that are independent of each other is exemplified, but a shaft with a single lumen structure may also be employed. Furthermore, the number of sub-lumens is not particularly limited as long as there are multiple sub-lumens. For example, the number of wire insertion lumens and molding lumens may be the same, or the number of wire insertion lumens may be fewer than the number of molding lumens. As shown in the second embodiment, the sub-lumen does not need to include a molding lumen. Furthermore, in the main lumen, for example, the insertion portion for the electrical wiring 22 and the insertion portion for the channel tube 24 may be independent of each other.

[0073] In the above embodiment, the description has been given of a structure in which the operation wires 34 (72) are attached to the tip of the bending movable portion 28 at four circumferential locations, allowing the bending movable portion 28 to bend in any radial direction. However, the degrees of freedom in the directions in which the bending movable portion 28 is allowed to bend may be two or more. Specifically, for example, a structure in which the bending movable portion 28 is bendable in only two radial directions by two operation wires 34 attached to the tip of the bending movable portion 28 on both radial sides of the main lumen 18 may also be employed. Furthermore, for example, a structure in which two operation wires 34 are attached to positions 90 degrees apart from each other in the circumferential direction of the bending movable portion 28, allowing the direction of bending deformation of the bending movable portion 28 to be set within a 90-degree range between the operation wires, may also be employed.

[0074] The bending movable portion 28 may be bent by pulling the operation wire 34 proximally to apply an external operation force, or by pushing the operation wire 34 distally to apply an external operation force. In the first embodiment, an example has been given in which an external operation force is applied to the operation wire 34 by rotating the first and second operation handles 52, 54 of the handpiece 16, but an external operation force may also be applied to the operation wire 34 by, for example, sliding an operation member connected to the proximal end of the operation wire 34.

[0075] DESCRIPTION OF SYMBOLS 10 Flexible endoscope (first embodiment) 12 Shaft 14 Distal tip 16 Handpiece 18 Main lumen (lumen) 20 Sub-lumen (lumen) 22 Electrical wiring 24 Channel tube 26 Shaft body 28 Bending movable portion 30 Soft tube 32 Covering tube 33 Plate 34 Operation wire 34a-d Operation wire 34a'-d' Branch portion (deformation restriction mechanism) 38 Peripheral wall portion 40 Bottom wall portion 42 Imaging device 44 Light source 46 Electrical fitting 48 Through hole 50 Housing 52 First operation handle 54 Second operation handle 58 Internal space 60 Shaft mounting hole 61 Kink-resistant tube 62 Kink-resistant tube 64 First rotation shaft 66 Second rotation shaft 70 Flexible endoscope (second embodiment) 72 Operation wire 72a-d Operating wire 74 Coil spring (deformation restriction mechanism)

Claims

1. A shaft with a hollow structure having lumens that penetrate in the longitudinal direction, A tip provided on the tip side of the shaft, An imaging device provided on the tip tip to acquire images from the tip side, A light source provided on the tip and projecting light toward the tip, Extending within the lumen of the shaft, electrical wiring connected to the imaging device and the light source, A curved movable part is provided at the tip of the shaft, which is allowed to bend and deform, An operating wire extends within the lumen of the shaft and is fixed to the tip of the curved movable part, allowing the bending deformation of the curved movable part to be controlled by an operating external force. Equipped with, The entire curved movable part is made of a flexible tube that is soft and does not have a skeletal structure. A flexible endoscope characterized by its restriction to single-use.

2. The flexible endoscope according to claim 1, wherein the shaft has a bendable movable portion and a shaft body on the proximal end side of the bendable movable portion, and the bending rigidity of the bendable movable portion is less than that of the shaft body.

3. The shaft has a curved movable portion and a shaft body located at the base end of the curved movable portion. The flexible endoscope according to claim 1 or 2, wherein a deformation regulating mechanism is provided to limit the amount of bending deformation of the shaft body when an external operating force is applied to the operating wire.

4. The flexible endoscope according to claim 3, wherein the operating wire fixed to a part of the circumferential direction of the curved movable part is branched into multiple parts at the proximal end, and the branched multiple operating wires are arranged at equal intervals in the circumferential direction of the shaft body.

5. In the shaft body, the operating wire is inserted through the coil spring. The flexible endoscope according to claim 3, wherein the deformation regulating mechanism is formed by the coil spring that contracts in response to the tension of the operating wire.

6. The lumen of the shaft comprises a main lumen and a plurality of sub-lumens arranged around the main lumen. The aforementioned electrical wiring is inserted into the main lumen, The flexible endoscope according to claim 1 or 2, wherein the operating wire is inserted through the sub-lumen.

7. The aforementioned plurality of sub-brumens are evenly arranged in the circumferential direction, The flexible endoscope according to claim 6, wherein the plurality of sub-lumens include a wire insertion lumen through which the operating wire is inserted and a shaping lumen through which the operating wire is not inserted.

8. The flexible endoscope according to claim 1 or 2, wherein the maximum bending angle of the curved movable part is 270 degrees or more.

9. The flexible endoscope according to claim 1 or 2, wherein the curved movable portion can be bent and deformed in any radial direction by operating a plurality of operating wires.