Outer sleeve

Abstract

The present invention addresses the problem of providing an outer cannula in which the tip side of the outer cannula can be inserted into the digestive tract. The outer sleeve (10) is provided with: a supply / discharge port (22) for supplying and discharging a fluid; a first region (T1), which is positioned further toward the tip side than the supply / discharge port (22), and which comprises an outer tube (30), an inner tube (32), and a shape-variable body (38); and a second region (T2), which is positioned further toward the tip side than the first region (T1), and which comprises an outer tube (30) and an inner tube (32). The first region (T1) can be switched between a first state in which a fluid is supplied to a pipe internal space (S) between the outer pipe (30) and the inner pipe (32) via the supply / discharge port (22) and a second state in which the fluid is discharged and which is harder than the first state, and the second region (T2) is softer than the second state of the first region (T1).

Description

Technical Field

[0001] The present invention relates to an outer sleeve having an insertion passage through which a medical instrument can be inserted. Background Art

[0002] There is known an overtube having an insertion channel through which a medical instrument such as an insertion portion of an endoscope (hereinafter also referred to as “endoscope insertion portion”) can be inserted.

[0003] For example, Patent Document 1 discloses a hardness-variable overtube (catheter). The overtube has a tube body in which an outer tube covers an inner tube, and a shape-variable body that can deform in accordance with the shape of the tube body is provided between the outer tube and the inner tube.

[0004] According to the overtube disclosed in Patent Document 1, when the internal space between the outer tube and the inner tube is decompressed, the overtube becomes a hard state (solidified state) while maintaining the shape of the shape-adjustable body. On the other hand, when the decompression of the internal space between the outer tube and the inner tube is released, the shape retention of the shape-adjustable body is released, and the overtube becomes a soft state (softened state). Thus, when the endoscope insertion part is inserted into the overtube, the overtube is switched between the solid state and the softened state, and the overtube and the endoscope insertion part are moved forward and backward relative to each other, so that the endoscope insertion part can be guided into the body.

[0005] Patent Document 1: International Publication No. 2022 / 181200

[0006] However, in the case of the variable hardness outer tube disclosed in Patent Document 1, when switching from a softened state to a solidified state, the outer tube becomes hard as a whole in the longitudinal direction, so the insertability of the front end of the outer tube relative to the digestive tract (especially the upper digestive tract) deteriorates. And the same is true when the outer tube is in a softened state. Therefore, the above-mentioned moving operation becomes complicated and difficult, and sometimes it is impossible to guide the endoscope insertion part to the desired direction. Summary of the invention

[0007] The present invention has been made in view of such circumstances, and an object of the present invention is to provide an overtube having improved insertability of the front end side of the overtube into the digestive tract.

[0008] The present invention includes the following inventions.

[0009] The outer sleeve involved in the first embodiment has an insertion passage that can be inserted into a medical device, and the outer sleeve has: a supply and discharge port located on the base end side and used to supply and discharge fluid; a first region located at a position closer to the front end side than the supply and discharge port and including a flexible outer tube, a flexible inner tube and a deformable shape-changing body arranged between the outer tube and the inner tube; and a second region located at a position closer to the front end side than the first region and including an outer tube and an inner tube, the first region can be switched between a first state in which fluid is supplied to the space between the outer tube and the inner tube via the supply and discharge port and a second state in which the fluid is discharged and is harder than the first state, and the second region is softer than the second state of the first region.

[0010] In the overtube according to the second aspect, in the first aspect, the second region is softer than the first state of the first region.

[0011] In the overtube according to the third aspect, in the first aspect or the second aspect, the distal end side of the second region is softer than the proximal end side of the second region.

[0012] The outer sleeve involved in the fourth aspect is any one of the first to third aspects, wherein the second region includes a shape-variable body, and the second region can be switched between a first state in which fluid is supplied to the space between the outer tube and the inner tube via the supply and discharge ports and a second state in which the fluid is discharged.

[0013] In the overtube according to the fifth aspect, in any one of the first to fourth aspects, the first state of the second region is softer than the first state of the first region, and the second state of the second region is softer than the second state of the first region.

[0014] In the outer sleeve involved in the 6th mode, in any one of the 1st to 5th modes, the first region is arranged between the outer tube and the inner tube and has an intermediate layer capable of contacting the shape-changing body. In the second state, the first region becomes hard by the first contact surface arranged on the shape-changing body contacting the second contact surface arranged in the intermediate layer and opposite to the first contact surface.

[0015] The overtube according to a seventh aspect is any one of the first to sixth aspects, wherein the second region includes an intermediate layer having a structure different from that of the intermediate layer in the first region.

[0016] The outer sleeve according to an eighth aspect is the seventh aspect, wherein the intermediate layer in the second region has constant flexibility along the longitudinal direction.

[0017] The overtube according to a ninth aspect is characterized in that, in the seventh aspect, the distal end side of the intermediate layer in the second region is softer than the proximal end side.

[0018] According to a tenth aspect, in the ninth aspect, the intermediate layer in the second region includes a first intermediate layer provided on the distal end side and a second intermediate layer provided on the proximal end side, and the first intermediate layer is softer than the second intermediate layer.

[0019] The overtube according to the eleventh aspect is characterized in that in the ninth aspect, the intermediate layer in the second region gradually becomes softer toward the distal end side.

[0020] The outer sleeve according to the twelfth aspect is any one of the seventh to eleventh aspects, wherein the intermediate layer is formed of a sheet material provided from the first region to the second region, and the cutout portion is provided in the sheet material in the second region.

[0021] According to a thirteenth aspect, in the twelfth aspect, the overtube is characterized in that the sheet in the first region is formed of a smooth surface.

[0022] In the overtube according to a fourteenth aspect, in any one of the sixth to thirteenth aspects, at least a portion of any one of the first contact surface and the second contact surface includes a high friction surface.

[0023] The overtube according to a fifteenth aspect is any one of the sixth to fourteenth aspects, wherein the intermediate layer is provided between the outer tube and the shape-adjustable body.

[0024] According to a sixteenth aspect, in any one of the first to fifteenth aspects, the outer sheath tube is characterized in that the shape-adjustable body has a spiral tube formed by spirally winding a belt-shaped member around the outer circumference of the inner tube.

[0025] The overtube according to the seventeenth aspect is any one of the first to sixteenth aspects, wherein the length of the second region in the longitudinal direction is 5 cm to 20 cm, and the base end of the second region is located within 20 cm from the distal end.

[0026] An overtube according to an eighteenth aspect is any one of the first to seventeenth aspects, wherein the length of the first region in the longitudinal direction is longer than that of the second region.

[0027] The overtube according to a nineteenth aspect is any one of the first to eighteenth aspects, wherein the length of the first region in the longitudinal direction is 20 cm or more.

[0028] The outer sleeve involved in the 20th aspect is any one of the 3rd aspect and the 9th aspect to the 11th aspect, wherein the length of the second region in the longitudinal direction is not less than 5 cm and not more than 50 cm, and the base end of the second region is set within 50 cm from the front end.

[0029] The insertion method of the endoscope insertion part involved in the 21st method uses the outer sleeve of any one of the first method to the 20th method, and the insertion method includes: an insertion step, inserting the endoscope insertion part from the mouth of the subject into the stomach in a state of being inserted in the outer sleeve; a positioning step, aligning the position where the front end of the endoscope insertion part is exposed from the front end of the outer sleeve; and a pylorus passing step, after performing the insertion step and the positioning step, pressing the endoscope insertion part and the outer sleeve together, and passing the endoscope insertion part and the outer sleeve through the pylorus.

[0030] The insertion method of the endoscope insertion portion according to the 22nd aspect is the method according to the 21st aspect, comprising: an introducing step of introducing the endoscope insertion portion together with the overtube and moving a part of the overtube toward the lesser curvature to reduce slack of the overtube.

[0031] The insertion method of the endoscope insertion portion according to the 23rd aspect is the method according to the 21st aspect or the 22nd aspect, and further includes a curing step of curing the overtube.

[0032] The insertion method of the endoscope insertion part involved in the 24th method uses an outer sleeve of any one of the first method to the 20th method, and the insertion method includes: an insertion step, inserting the endoscope insertion part from the mouth of the subject into the stomach in a state of being inserted in the outer sleeve; an endoscope passing through the pylorus step, after the insertion step, pressing the endoscope insertion part and passing at least a part of the curved part of the endoscope insertion part through the pylorus; and an outer sleeve passing through the pylorus step, after the endoscope passing through the pylorus step, pressing the outer sleeve to pass it through the pylorus.

[0033] The insertion method of the endoscope insertion portion according to the 25th aspect includes, in the 24th aspect, a positioning step of performing positioning at a position where the front end of the endoscope insertion portion is exposed from the front end of the overtube after the overtube passes through the pylorus step.

[0034] The insertion method of the endoscope insertion portion according to the 26th aspect includes, in the 24th aspect or the 25th aspect, an introducing step of introducing the endoscope insertion portion together with the outer sleeve and moving a part of the outer sleeve toward the lesser curvature to reduce the slack of the outer sleeve.

[0035] The insertion method of the endoscope insertion portion according to a 27th aspect is any one of the 24th to 26th aspects, and includes a curing step of curing the overtube.

[0036] The insertion method of the endoscope insertion portion according to the twenty-eighth aspect is the method according to the twenty-seventh aspect, and includes an inserting step of, after the curing step, pushing the endoscope insertion portion relative to the overtube and inserting the endoscope insertion portion into a deep portion of the body.

[0037] Effects of the Invention

[0038] According to the present invention, the insertability of the distal end side of the overtube into the digestive tract can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram showing the structure of an endoscope device.

[0040] Figure 2 It is a schematic cross-sectional view showing the structure of the first region of the outer sleeve.

[0041] Figure 3 It is a schematic cross-sectional view showing the structure of the second region of the outer sleeve.

[0042] Figure 4 It is a diagram showing a state where the overtube is pushed into the insertion portion of the endoscope.

[0043] Figure 5 This is a flowchart showing the flow of the first example of the pylorus passage technique.

[0044] Figure 6 This is an explanatory diagram for explaining the first example of the pylorus passing technique.

[0045] Figure 7 This is a flowchart showing the flow of the second example of the pylorus passage technique.

[0046] Figure 8 This is an explanatory diagram for explaining the second example of the pylorus passing technique.

[0047] Fig. 9 It is a schematic cross-sectional view showing the structure of an overtube according to a second embodiment.

[0048] Fig.10 This is a diagram showing a sheet material included in the overtube according to the second embodiment developed in a planar shape.

[0049] Fig.11 This is an external view in which the outer tube is omitted from the overtube of the second embodiment.

[0050] Fig.12 This is a diagram showing a sheet according to the first modification example developed in a planar form.

[0051] Fig.13 This is a diagram showing a sheet according to the second modification example developed into a planar shape.

[0052] Fig.14 This is a diagram showing a sheet according to the third modification example developed into a planar shape.

[0053] Fig.15 This is a diagram showing a sheet according to the fourth modification example developed into a planar shape.

[0054] Fig.16 This is a diagram showing a sheet according to the fifth modification example developed into a planar shape.

[0055] Fig.17 This is a diagram showing a sheet according to the sixth modification example unfolded into a planar shape.

[0056] Fig.18 It is a diagram showing the evaluation results of the bending condition of the outer sleeve.

[0057] Fig.19 This is a graph showing the results of measuring the hardness of the second region of the outer sleeve.

[0058] Fig. 20 It is a diagram showing another configuration example of the overtube according to the first embodiment. DETAILED DESCRIPTION

[0059] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0060] [First embodiment]

[0061] Figure 1 1 is a schematic diagram showing the structure of the endoscope device 1. Figure 1 As shown, the endoscope device 1 includes an overtube 10 and an endoscope 100. Hereinafter, before describing the specific structure of the overtube 10 to which the present invention is applied, the structure of the endoscope 100 will be briefly described.

[0062] <Endoscope>

[0063] The endoscope 100 includes a long insertion portion 102 (hereinafter referred to as “endoscope insertion portion 102 ”) inserted into a body, and a handheld operation portion 110 connected to a proximal end side of the endoscope insertion portion 102 .

[0064] The endoscope insertion portion 102 is composed of a distal end portion 104 , a bending portion 106 , and a flexible portion 108 in this order from the distal end side toward the proximal end side.

[0065] Although not shown in the figure, a pair of lighting windows for illuminating the inside of the body, an observation window for observing the inside of the body, a treatment tool outlet for guiding out treatment tools, and a cleaning nozzle for cleaning the observation window are provided on the front end surface 104a of the front end portion 104.

[0066] The bending portion 106 is bent in a desired direction by operating a pair of angle knobs (not shown) provided on the handheld operating portion 110. The soft portion 108 is composed of a soft component having flexibility in the bending direction. In addition, the structure of the endoscope 100 is not directly related to the present invention, and a known structure can be applied, so further description is omitted.

[0067] <Outer sleeve>

[0068] Next, the structure of the overtube 10 will be described. The overtube 10 is a device for guiding the endoscope insertion portion 102 into the body, and is a variable hardness overtube whose hardness can be changed. The endoscope insertion portion 102 is an example of the medical instrument of the present invention.

[0069] like Figure 1 As shown in FIG. 1 , the outer sleeve 10 is a long member formed along a long axis C extending from the front end 10a to the base end 10b. In addition, in the direction along the long axis C, one side (the front end 10a side) is referred to as the front end direction ( Figure 1 The symbol C1 direction) or the front end side, the other side (base end 10b side) which will be the direction opposite to the side is called the base end direction ( Figure 1 Symbol C2 direction) or base end side.

[0070] An insertion passage 14 is provided inside the outer tube 10 along the long axis C. The insertion passage 14 opens at two locations, the front end 10a and the base end 10b of the outer tube 10, and the opening on the front end side (front end opening) and the opening on the base end side (base end opening) are connected. The inner diameter of the insertion passage 14 is formed to be larger than the outer diameter of the endoscope insertion portion 102, so that the endoscope insertion portion 102 can be inserted into the insertion passage 14.

[0071] A distal end cap 18 is provided on the distal end side of the outer tube 10 , and a proximal end cap 20 is provided on the proximal end side.

[0072] The portion of the outer tube 10 other than the front end cap 18 and the base end cap 20 (hereinafter referred to as the "tube body"), that is, the area occupying most of the area other than the two end portions (the front end side and the base end side) along the long axis C is formed into a cylindrical shape elongated along the long axis C. In addition, the details will be described later, and the tube body constituting the outer tube 10 is composed of a double structure tube with an outer tube 30 covering the periphery of the inner tube 32, and a space S (hereinafter referred to as the "tube internal space S") is provided between the outer tube 30 and the inner tube 32 (refer to Figure 2 ).

[0073] The front end cap 18 is a member constituting the front end side of the outer tube 10. The front end cap 18 is a hard resin cylindrical body coaxially fixed to the front end side of the tube body, and constitutes the opening on the front end side of the outer tube 10 and a part of the insertion passage 14. In addition, the front end cap 18 also serves as a sealing member for sealing the end portion of the front end side of the tube internal space S.

[0074] The proximal end cap 20 is a member constituting the proximal end side of the outer tube 10. The proximal end cap 20 is a hard resin cylindrical body coaxially fixed to the proximal end side of the tube body, and constitutes the proximal end side opening of the outer tube 10 and a part of the insertion passage 14. In addition, the proximal end cap 20 also serves as a sealing member for sealing the end portion of the proximal end side of the tube internal space S.

[0075] The proximal end cap 20 has a predetermined length along the long axis C (at least a length that can be grasped by an operator such as a surgeon or an assistant), and functions as a grasping portion grasped by the operator.

[0076] A supply and discharge port 22 is provided on the outer peripheral surface of the base end cap 20. The supply and discharge port 22 is connected to the tube internal space S via a connecting pipe (not shown) provided inside the outer peripheral wall of the base end cap 20. The supply and discharge port 22 is connected to the pump 26 via a fluid supply and discharge pipe 24. Thus, by operating the pump 26, the fluid (in this example, air) can be supplied to and discharged from the tube internal space S through the supply and discharge port 22. In addition, the fluid fed into the tube internal space S is not limited to air, and various other gases can also be used, and liquids can also be used.

[0077] The outer tube 10 has a first region T1 located at a position closer to the front end side than the supply and discharge port 22, and a second region T2 located at a position closer to the front end side than the first region T1. Specifically, the second region T2 is a region having a predetermined length from the front end (the base end of the front end cover 18) of the tube body constituting the outer tube 10 toward the base end direction C2. The first region T1 is a region from the base end of the second region T2 to the base end of the tube body (the front end of the base end cover 20).

[0078] In addition, it is not necessary to provide the front end cap 18 at the front end side of the outer tube 10. In this case, the tube internal space S is sealed at the front end side of the tube body. When the front end cap 18 is not provided, the front end 10a of the outer tube 10 is substantially consistent with the front end of the second region T2.

[0079] Next, the structures of the first region T1 and the second region T2 of the outer sleeve 10 will be described in detail. Figure 2 It is a schematic cross-sectional view showing the structure of the first region T1 of the overtube 10 . Figure 3 2 is a schematic cross-sectional view showing the structure of the second region T2 of the outer sleeve 10. Figure 3 In order to show the difference between the first region T1 and the second region T2, a part of the first region T1 is also shown. Hereinafter, the same structure in the first region T1 and the second region T2 is described, and then the different structure in the first region T1 and the second region T2 is described.

[0080] like Figure 2 and Figure 3As shown in the figure, the tube body constituting the outer tube 10 has a cylindrical tube outer peripheral wall 16 extending from the front end to the base end. The tube outer peripheral wall 16 is composed of a double structure tube in which the outer tube 30 covers the inner tube 32. That is, the tube body has a flexible outer tube 30 and a flexible inner tube 32 arranged inside the outer tube 30, and a tube internal space S is provided between the outer tube 30 and the inner tube 32. A shape-adjustable body 38 and a sheet 40 described later are arranged in the tube internal space S. In addition, as described later, in this embodiment, the sheet 40 is arranged only in the first region T1.

[0081] The outer tube 30 and the inner tube 32 are respectively made of a soft resin material such as urethane or polyester resin. In addition, the outer tube 30 and the inner tube 32 are not limited to the above examples, and any material having an elastic modulus of about 5 MPa (megapascal, hereinafter the same) to 20 MPa at an elongation of 100% (percentage, the same below) obtained by a method described in JIS K7161 (tensile test) or a method in accordance therewith can be applied.

[0082] As an example, the thickness of the outer tube 30 and the inner tube 32 is about 100 μm (micrometer, the same below) to 200 μm. In addition, from the viewpoint of preventing damage, the thickness of the outer tube 30 is preferably thicker than the thickness of the inner tube 32. In addition, the rigidity of the outer tube 30 and the inner tube 32 is smaller than the rigidity of the sheet 40 described later.

[0083] The tube internal space S is a space formed in an annular (donut-shaped) shape in a cross-sectional shape in a direction orthogonal to the long axis C so as to surround the periphery (outer periphery) of the inner tube 32. The tube internal space S is formed into a closed space by sealing the outer tube 30 and the inner tube 32 at the distal end side and the proximal end side of the outer tube 10 using the aforementioned distal end cap 18 and proximal end cap 20.

[0084] For example, when the thickness D of the outer peripheral wall 16 of the outer tube 10 in the softened state is set to 1 mm (millimeter, the same below) or less, the thickness of the tube internal space S is about 600 μm to 800 μm. In addition, the thickness of each of the outer tube 30, the inner tube 32 and the tube internal space S is not limited to the above thickness, and can be set according to the diameter of the endoscope insertion part 102 and the diameter of the insertion path of the object inserted into the endoscope insertion part 102. In addition, the inner diameter of the inner tube 32 (that is, the inner diameter of the insertion path 14) is also set according to the outer diameter of the endoscope insertion part 102, and the inner diameter is, for example, about 6 mm to 16 mm.

[0085] The outer circumferential surface 30a of the outer tube 30 and the inner circumferential surface 32a of the inner tube 32 each have a hydrophilic coating. By forming the hydrophilic coating on the outer circumferential surface 30a of the outer tube 30, the frictional resistance between the outer tube 30 and the wall of the digestive tract can be reduced. As a result, the insertability (advancing property) of the outer tube 10 relative to the body is improved. In addition, by forming the hydrophilic coating on the inner circumferential surface 32a of the inner tube 32, the frictional resistance between the inner tube 32 and the endoscope insertion part 102 can be reduced. As a result, the insertability of the endoscope insertion part 102 relative to the outer tube 10 is improved.

[0086] In addition, in this example, a mode in which the hydrophilic coating is formed on both the outer tube 30 and the inner tube 32 is shown, but the present invention is not limited thereto, and the hydrophilic coating may be formed on at least one of the outer tube 30 and the inner tube 32. However, by forming the hydrophilic coating on both the outer tube 30 and the inner tube 32, the above-mentioned two effects can be obtained, which is preferable.

[0087] A shape-adjustable body 38 is provided between the outer tube 30 and the inner tube 32 (i.e., the tube internal space S). Figure 2 and Figure 3 As shown in the figure, the shape-adjustable body 38 is a member provided from the front end to the base end of the tube body constituting the outer tube 10, and is respectively arranged in the first region T1 and the second region T2. ​​The shape-adjustable body 38 is composed of a spiral tube formed by spirally winding a strip-shaped member along the long axis C around the outer circumference of the inner tube 32. The shape-adjustable body 38 has flexibility in the bending direction and can be deformed following the shape of the outer tube 10. For example, when the outer tube 10 in a softened state is deformed into a curved shape or other arbitrary shape, the shape-adjustable body 38 will also be deformed following the shape.

[0088] The strip-shaped member constituting the spiral tube is made of stainless steel (SUS: Steel Use Stainless). In addition, the strip-shaped member is not limited to being made of stainless steel, and any material that can be deformed along with the shape of the outer tube 10 can be applied. For example, the strip-shaped member can be formed of plastic or the like. For example, when the thickness D of the outer peripheral wall 16 of the outer tube 10 in the softened state is set to 1 mm or less, the thickness of the strip-shaped member is preferably 300 μm or less.

[0089] Next, the different structures in the first region T1 and the second region T2 are described. Figure 2 and Figure 3 As shown, the outer sleeve 10 in this embodiment has different structures in the first region T1 and the second region T2. ​​The structure of the first region T1 will be described below, and then the structure of the second region T2 will be described.

[0090] The first region T1 is a region located on the proximal side of the second region T2. ​​The length of the first region T1 in the longitudinal direction (the direction along the long axis C, the same below) is configured to be longer than the length of the second region T2 in the longitudinal direction. Specifically, the length of the first region T1 in the longitudinal direction is at least 20 cm (centimeter, the same below) or more, for example, 20 cm or more and 100 cm or less.

[0091] The first region T1 can be switched between a softened state (also referred to as a flexible state or a non-solidified state, which corresponds to the "first state" of the present invention) in which air (an example of "fluid") is supplied to the tube internal space S between the outer tube 30 and the inner tube 32 via the supply and discharge port 22, and a second state (also referred to as a solidified state or a hard state, which corresponds to the "second state" of the present invention) which is harder than the first state in which air is discharged from the tube internal space S. Specifically, the first region T1 has the following structure.

[0092] like Figure 2 As shown, as described above, the first region T1 has an outer tube 30, an inner tube 32 and a shape-adjustable body 38. In addition, a sheet 40 is provided in the first region T1. The sheet 40 is an intermediate layer disposed between the outer tube 30 and the inner tube 32, and is disposed in a manner that allows it to contact the shape-adjustable body 38. Specifically, the sheet 40 is between the outer tube 30 and the shape-adjustable body 38, and has a cylindrical shape in a manner that surrounds the shape-adjustable body 38. In addition, the sheet 40 is provided throughout the entire length direction in the first region T1. In addition, as described later, in the present embodiment, the sheet 40 is not provided in the second region T2. ​​In addition, the sheet 40 has flexibility that allows it to deform following the shape of the outer sleeve 10.

[0093] As an example, the sheet 40 is made of a resin such as urethane. However, it is not limited to this, and for example, an aluminum vapor-deposited film can also be used. The aluminum vapor-deposited film is formed by vacuum vapor-depositing (thermocompression bonding) aluminum (aluminum foil) on the surface of a base film. By using an aluminum vapor-deposited film as the sheet 40, the rigidity of the sheet 40 can be improved. In this case, as the base film, a heat-sealable film such as PET (Polyethylene terephthalate) or PE (polyethylene) can be exemplified. In addition, the elastic modulus of the sheet 40 is preferably higher than the elastic modulus of the outer tube 30 and the inner tube 32. In addition, the elastic modulus of the sheet 40 is obtained by the method described in JIS K7161 (tensile test) or a method in accordance therewith. Thus, the outer tube 30 and the inner tube 32 can be reinforced by the sheet 40. That is, the tensile strength and tensile rigidity of the outer sleeve 10 are improved by the sheet 40. As a result, the forward movement of the outer sleeve 10 in the softened state is improved. By using a material obtained by combining an aluminum vapor-deposited film or an aluminum foil with various cloths and films, a material having an optimal elastic modulus can be selected.

[0094] For example, when the thickness of the outer peripheral wall 16 of the outer tube 10 in the softened state is set to 1 mm or less, the thickness of the sheet 40 is preferably 300 μm or less. However, from the viewpoint of rigidity, the sheet 40 is preferably thicker than the thickness of the outer tube 30 and the inner tube 32. Furthermore, when an aluminum vapor-deposited film is used as the sheet 40, the rigidity of the outer tube 10 can be changed by changing its base film. As a result, the hardness of the outer tube 10 in the softened state can be adjusted to a hardness suitable for the insertion site (upper digestive tract or lower digestive tract) of the endoscope insertion portion 102.

[0095] The sheet 40 has a first contact surface 40a on the side (inner peripheral surface side) opposite to the shape-adjustable body 38. The first contact surface 40a is a surface that can contact the shape-adjustable body 38, and the entire surface is composed of a high friction surface. That is, the sheet 40 of this example is composed of a friction sheet having a high friction surface on the surface (first contact surface 40a) on the side opposite to the shape-adjustable body 38. Thus, the first contact surface 40a of the sheet 40 is in high friction contact with the shape-adjustable body 38, and the first contact surface 40a can limit the movement of the shape-adjustable body 38 in the direction along the major axis C, thereby improving the shape retention force of the shape-adjustable body 38.

[0096] The high friction surface is formed, for example, by a resin layer coated with a resin such as a urethane coating or a silica coating on the inner peripheral surface of the sheet 40. In addition, the high friction surface can also be formed by a rough surface with fine bumps formed on the inner peripheral surface of the sheet 40. In addition, the rough surface is formed by roughening treatment such as sandblasting, laser irradiation, chemical treatment or etching. In addition, the high friction surface can also be a high friction surface obtained by coating the above-mentioned resin on the surface obtained by roughening the inner peripheral surface of the sheet 40, or a high friction surface obtained by roughening the surface obtained by coating the above-mentioned resin on the inner peripheral surface of the sheet 40.

[0097] Here, in this specification, a "high friction surface" refers to a surface having a higher friction coefficient than a surface (in this example, the inner peripheral surface of the outer tube 30) in contact with the shape-adjustable body 38 when the sheet 40 is not present. That is, the "high friction surface" generates a higher friction resistance than the friction resistance when the shape-adjustable body 38 and the outer tube 30 are in direct contact when the sheet 40 is not present. The friction coefficient of the "high friction surface" can be measured, for example, by the method described in JIS P8147:2010 or a method in accordance therewith.

[0098] Furthermore, in the present specification, "cannot be deformed" means that the shape of the shape-adjustable body 38 is fixed when the air in the tube internal space S is exhausted. Furthermore, in the present specification, "friction engagement" means that the contact surfaces that are in contact with each other are engaged with each other by friction. The friction force is the friction force (static friction force) generated when the respective contact surfaces are in contact with each other in the radial direction of the outer tube 10 when the outer tube 10 is viewed from the direction along the long axis C. Furthermore, each contact surface is formed into a substantially circular shape when viewed from the direction of the long axis C.

[0099] In addition, in the present embodiment, as an example, the first contact surface 40a of the sheet 40 on the side (inner peripheral surface side) opposite to the shape-adjustable body 38 is shown as a high friction surface, but the present invention is not limited thereto, and the second contact surface 38a of the shape-adjustable body 38 on the side (outer peripheral surface side) opposite to the sheet 40 may be a high friction surface. In addition, both the first contact surface 40a of the sheet 40 and the second contact surface 38a of the shape-adjustable body 38 may be high friction surfaces. That is, as long as at least one of the first contact surface 40a of the sheet 40 and the second contact surface 38a of the shape-adjustable body 38 is a high friction surface, it will suffice.

[0100] Furthermore, in the present embodiment, the high friction surface may be formed on the entirety of at least one of the first contact surface 40a and the second contact surface 38a, or may be formed on a portion of any one of the contact surfaces. That is, the high friction surface only needs to be formed on at least a portion of any one of the contact surfaces. However, from the viewpoint of improving the shape retention of the shape-adjustable body 38, it is preferred that the high friction surface is formed on the entirety of any one of the contact surfaces, and further, it is more preferred that the high friction surface is formed on the entirety of both contact surfaces. Furthermore, from the viewpoint of ensuring the softness of the outer sleeve 10 in the softened state, the gap between the shape-adjustable body 38 and the sheet 40 is preferably about 50 μm to 500 μm.

[0101] Furthermore, the sheet material 40 in the present embodiment is formed into a sheet shape by a smooth surface without cutouts such as cutout holes or cutout lines, but the present invention is not limited thereto, and as long as the hardness of the first region T1 in the outer sleeve 10 can be made higher than that of the second region T2, a cutout may be provided on the sheet material 40. Furthermore, the sheet material 40 is not limited to one sheet material, and may be formed of a plurality of sheets.

[0102] Next, the structure of the second region T2 will be described.

[0103] like Figure 3 As shown, the second region T2 has the outer tube 30, the inner tube 32 and the shape-adjustable body 38, which is the same as the first region T1. In the second region T2, there is no sheet 40 between the outer tube 30 and the shape-adjustable body 38, which is different from the first region T1. Therefore, the second region T2 is configured as a softer region than the first region T1.

[0104] That is, in this embodiment, in order to configure the second region T2 in the outer tube 10 to be a region softer than the first region T1, the first region T1 in the outer tube 10 is configured to have a structure in which the sheet 40 is present between the outer tube 30 and the shape-adjustable body 38, and on the other hand, the second region T2 is configured to have a structure in which the sheet 40 is not present between the outer tube 30 and the shape-adjustable body 38.

[0105] Furthermore, the second region T2, like the above-mentioned first region T1, can be switched between a softened state in which air is supplied to the tube internal space S between the outer tube 30 and the inner tube 32 via the supply and exhaust port 22 (equivalent to the “first state” of the present invention) and a solidified state in which air is exhausted from the tube internal space S and is harder than the softened state (equivalent to the “second state” of the present invention). However, due to the difference in the configuration of the above-mentioned sheet 40, the hardness of the second region T2 in each state is softer than the hardness of the corresponding first region T1 in each state.

[0106] Specifically, when the outer tube 10 is in a solidified state (second state) (i.e., when the first region T1 and the second region T2 are in a solidified state), the second region T2 is configured to be softer than the first region. Furthermore, when the outer tube 10 is in a softened state (first state) (i.e., when the first region T1 and the second region T2 are in a softened state), the second region T2 is configured to be softer than the first region.

[0107] According to this structure, the second region T2 is configured as a region softer than the first region T1 regardless of whether the outer tube 10 is in a solidified state or a softened state. Therefore, for example, even when the endoscope insertion portion 102 is bent while being inserted into the outer tube 10 in a solidified state, since the second region T2 is configured as a region softer than the first region T1, the bending action is not significantly hindered by the outer tube 10 in a solidified state, and a sufficient bending amount can be obtained.

[0108] Furthermore, when the outer tube 10 and the endoscope insertion portion 102 in the softened state are relatively moved forward and backward, for example, Figure 4 As shown, even when the bending amount of the endoscope insertion portion 102 led out from the front end of the outer tube 10 is large, since the second region T2 is constructed as a softer region than the first region T1, it will not be caught by wrinkles and the like generated on the curved portion 106 of the endoscope insertion portion 102, and the outer tube 10 can be smoothly pressed in following the wall surface of the digestive tract.

[0109] Here, the length of the second region T2 in the longitudinal direction is preferably 5 cm or more and 20 cm or less (more preferably 7 cm or more and 15 cm or less). Furthermore, the base end of the second region T2 is preferably set at a position within 20 cm from the front end 10a of the outer tube 10. In addition, the above-mentioned length and position are preferably determined according to the bending length of the endoscope insertion portion 102 used in combination with the outer tube 10 (the length from the front end of the endoscope insertion portion 102 to the base end of the curved portion 106). In addition, as an example, the bending length of the endoscope insertion portion 102 is 7 cm in the upper endoscope and 10 cm in the lower endoscope.

[0110] By setting the second region T2 to the above-mentioned length and position, when the endoscope insertion portion 102 is inserted into the overtube 10 and the front end 10a of the overtube 10 is aligned with the front end of the endoscope insertion portion 102, the second region T2 is arranged in the region where at least the curved portion 106 of the endoscope insertion portion 102 is arranged. Thus, even when the endoscope insertion portion 102 is introduced into the overtube 10 and the front end 10a of the overtube 10 is roughly aligned with the front end of the endoscope insertion portion 102, the second region T2 exists at a position corresponding to the curved portion 106 of the endoscope insertion portion 102. Therefore, even when the endoscope insertion portion 102 is bent in a state where the overtube 10 and the curved portion 106 of the endoscope insertion portion 102 overlap, the bending action is not greatly hindered by the overtube 10, so a sufficient bending amount can be obtained, and the endoscope insertion portion 102 can be guided to a desired direction.

[0111] According to the outer sleeve 10 constructed as above, in the first region T1, when the air in the tube internal space S is discharged by the pump 26, the inner peripheral surface of the outer tube 30 is pressed and tightly fitted by the shape-adjustable body 38 with the sheet 40, and the outer peripheral surface of the inner tube 32 is pressed and tightly fitted by the shape-adjustable body 38, thereby fixing the position of the shape-adjustable body 38. As a result, the first region T1 changes from a softened state (first state) to a solidified state (second state) that is harder than the softened state. At this time, the shape-adjustable body 38 and the sheet 40 are tightly and frictionally engaged with each other with the high friction surface. As a result, the movement of the shape-adjustable body 38 in the direction of the major axis C is restricted, so that the shape (for example, the curved shape) of the shape-adjustable body 38 is maintained as being unable to deform, thereby improving the shape retention force of the first region T1 in the solidified state. On the contrary, if air is allowed to flow into the tube internal space S from the state where the air is discharged, the shape retention of the shape-adjustable body 38 is released, so that the first region T1 changes from a solidified state to a softened state.

[0112] On the other hand, in the second region T2, when the air in the tube internal space S is discharged by the pump 26, the inner peripheral surface of the outer tube 30 is pressed and tightly fitted by the shape-adjustable body 38, and the outer peripheral surface of the inner tube 32 is pressed and tightly fitted by the shape-adjustable body 38, thereby fixing the position of the shape-adjustable body 38. As a result, the second region T2 changes from a softened state (first state) to a solidified state (second state) that is harder than the softened state. At this time, the sheet 40 is not provided in the second region T2, so the second region T2 that has become a solidified state is softer than the solidified state of the first region T1. On the contrary, if air is allowed to flow into the tube internal space S from a state where the air is discharged, the second region T2 changes from a solidified state (second state) to a softened state (first state). The sheet 40 is also not provided in the second region T2 in the softened state, so it is softer than the softened state of the first region T1.

[0113] Thus, the second region T2 is configured to be softer than the corresponding states (i.e., the solidified state and the softened state) of the first region T1 in either the solidified state or the softened state. Therefore, the insertability of the front end side of the overtube 10 relative to the digestive tract (especially the upper digestive tract) is improved. Thus, in either state, the endoscope insertion portion 102 can be stably held by the first region T1, and the endoscope insertion portion 102 can be guided to a desired direction by the second region T2. ​​As a result, in the case of performing the pylorus passing technique described later, etc., the overtube 10 and the endoscope insertion portion 102 can be easily moved in the body.

[0114] <Pyloric Trans-Technique>

[0115] As an example of an operation using the overtube 10 of this embodiment, a technique for passing the endoscope insertion portion 102 through the pylorus between the stomach and the small intestine (pyloric passage technique) is described. In addition, the pyloric passage technique is an example, and even other operations that partially include the same operation as the pyloric passage technique can be implemented by combining the same process as the pyloric passage technique.

[0116] [First case of pyloric trans-apoptosis technique]

[0117] refer to Figure 5 and Figure 6 The first example of the pylorus trans-apoptosis technique is described. Figure 5 This is a flowchart showing the flow of the first example of the pylorus passage technique. Figure 6 1 is an explanatory diagram for explaining the first example of the pylorus passing technique. In addition, when starting this process, it is assumed that the outer tube 10 is in a softened state. The same is true in the second example described later.

[0118] (Step S10: Insertion Step)

[0119] First, with the endoscope insertion portion 102 inserted through the overtube 10 , the endoscope insertion portion 102 and the overtube 10 are inserted into the stomach 200 from the mouth of the subject.

[0120] (Step S12: Positioning Step)

[0121] Then, if Figure 6 As shown in FIG. 5A , the end portion 104 of the endoscope insertion portion 102 is aligned at a position where the end portion 104 is exposed from the front end opening of the outer tube 10. The alignment is performed by moving the endoscope insertion portion 102 in the base end direction C2 (proximal side) relative to the outer tube 10 or by moving the outer tube 10 in the front end direction C1 (distal side) relative to the endoscope insertion portion 102.

[0122] In addition, the insertion step may be performed after the alignment step. By performing the insertion step after the alignment step, the field of view in the front of the insertion direction can be obtained through the lighting window and the observation window at the front end of the endoscope insertion part 102, and the overtube 10 and the endoscope insertion part 102 can be inserted into the stomach 200.

[0123] (Step S14: Pylorus passing step)

[0124] Then, if Figure 6 As shown in FIG. 6A , the endoscope insertion portion 102 and the outer tube 10 are pushed in together, and the endoscope insertion portion 102 and the outer tube 10 are passed through the pylorus 202. Specifically, the endoscope insertion portion 102 and the outer tube 10 are pushed in together while the bending portion 106 is bent to guide the front end portion 104 of the endoscope insertion portion 102 toward the pylorus 202. At this time, since the second region T2 of the outer tube 10 in the softened state is configured as a region softer than the first region T1, the second region T2 can bend following the bending action of the endoscope insertion portion 102. Therefore, the bending movement of the endoscope insertion part 102 is not greatly hindered by the second region T2 (that is, the degree of freedom of the bending movement of the endoscope insertion part 102 is not greatly restricted), so the endoscope insertion part 102 can be pushed in together with the overtube 10 while the front end 104 of the endoscope insertion part 102 is guided toward the pylorus 202 by the bending movement of the endoscope insertion part 102. As a result, the endoscope insertion part 102 and the overtube 10 can be easily and stably passed through the pylorus 202.

[0125] (Step S16: Introduction Step)

[0126] Then, if Figure 6 As shown in FIG. VI, the endoscope insertion portion 102 and the outer tube 10 are introduced together, and a portion of the outer tube 10 is moved toward the lesser curvature 204 to reduce the slack of the outer tube 10. Here, after the pylorus passing step is performed, as shown in FIG. Figure 6 As shown in FIG. 6A and FIG. 6B , a large amount of slack is generated in a part (middle part) of the overtube 10 inside the stomach 200. If such slack is generated in the overtube 10, sometimes it is hindered when the overtube 10 and the endoscope insertion part 102 are pushed further into the deep part of the body. Therefore, it is preferable to make the overtube 10 and the endoscope insertion part 102 in a state close to a straight line at this stage so that the overtube 10 and the endoscope insertion part 102 can be pushed further into the deep part of the body. Therefore, after the pylorus passing step is performed, in order to eliminate the slack of the overtube 10 generated inside the stomach 200, the introduction step is performed. As a result, compared with before the introduction step is performed, the slack of the overtube 10 inside the stomach 200 is eliminated (stretched state).

[0127] (Step S18: Curing Step)

[0128] Next, the outer tube 10 is cured. Specifically, the pump 26 is operated to discharge the air in the tube internal space S through the supply and discharge port 22. Thus, in the first region T1, the outer tube 30 and the inner tube 32 are gradually pressed by the shape-adjustable body 38 that deforms following the shape of the outer tube 10. In addition, the inner circumferential surface of the outer tube 30 is pressed and tightly fitted by the shape-adjustable body 38 with the sheet 40 sandwiched therebetween, and the outer circumferential surface of the inner tube 32 is pressed and tightly fitted by the shape-adjustable body 38, thereby fixing the position of the shape-adjustable body 38. As a result, the first region T1 changes from a softened state to a cured state. At this time, the shape-adjustable body 38 and the sheet 40 are tightly and frictionally engaged with each other with the high friction surface sandwiched therebetween. Thus, the shape (for example, a curved shape) of the shape-adjustable body 38 is kept in a non-deformable state, so that the first region T1 is cured in a shape corresponding to the shape-adjustable body 38.

[0129] Furthermore, when the pump 26 is operated to discharge the air in the tube internal space S through the supply and discharge port 22, in the second region T2, the inner circumferential surface of the outer tube 30 is pressed and closely attached by the shape-adjustable body 38, and the outer circumferential surface of the inner tube 32 is pressed and closely attached by the shape-adjustable body 38, thereby fixing the position of the shape-adjustable body 38. As a result, the second region T2 changes from a softened state to a solidified state that is harder than the softened state. At this time, the sheet 40 is not provided in the second region T2, so the second region T2 that has changed to a solidified state is softer than the solidified state of the first region T1.

[0130] Therefore, when the air in the tube internal space S is exhausted through the supply and exhaust port 22, the first region T1 of the outer tube 10 becomes a solidified state, and the second region T2 located at the front end side of the first region T1 becomes a softer state than the solidified state of the first region T1. Thus, the endoscope insertion portion 102 can be kept in a stable state without swinging in the body by the first region T1, and the endoscope insertion portion 102 can be guided to a desired direction by the second region T2. ​​As a result, the insertability of the endoscope insertion portion 102 is improved.

[0131] Then, the curved portion 106 of the endoscope insertion portion 102 is protruded forward from the front end opening of the outer tube 10, and the treatment tool (not shown) is led forward from the treatment tool lead-out port of the front end portion 104, thereby starting treatment such as ESD (Endoscopic Submucosal Dissection). At this time, since the insertability of the endoscope insertion portion 102 is improved by the outer tube 10 in a solidified state, the front end portion 104 can be located at a correct treatment position, and as a result, the site to be treated (lesion, etc.) can be treated correctly.

[0132] In addition, in the first example described above, the case where the treatment of the part to be treated is performed in a state where the overtube 10 that has passed through the pylorus 202 is set to a solid state only once is described, but it is not limited to this. For example, the following operation may be performed: while the overtube 10 that has passed through the pylorus 202 is changed between a softened state and a solidified state multiple times, the endoscope insertion part 102 and the overtube 10 are respectively advanced in stages to perform the treatment of the part to be treated. The operation at this time includes: a process of advancing the endoscope insertion part 102 relative to the overtube 10 in a state where the overtube 10 through which the endoscope insertion part 102 is inserted is set to a solid state (endoscope insertion part advancing process); and a process of advancing the overtube 10 relative to the endoscope insertion part 102 in a state where the overtube 10 through which the endoscope insertion part 102 is inserted is set to a softened state (overtube advancing process). The same is true in the second example described later.

[0133] [Second example of pyloric trans-apoptotic technique]

[0134] refer to Figure 7 and Figure 8 The second example of the pylorus trans-apoptosis technique is described. Figure 7 This is a flowchart showing the flow of the second example of the pylorus passage technique. Figure 8 This is an explanatory diagram for explaining the second example of the pylorus passing technique.

[0135] (Step S20: Insertion Step)

[0136] First, with the endoscope insertion portion 102 inserted through the overtube 10 , the endoscope insertion portion 102 and the overtube 10 are inserted into the stomach 200 from the mouth of the subject.

[0137] (Step S22: Endoscope passing through pylorus)

[0138] Then, if Figure 8 As shown in FIG. VIIIA, the endoscope insertion portion 102 is pushed in, and at least a portion of the curved portion 106 of the endoscope insertion portion 102 passes through the pylorus 202. At this time, the endoscope insertion portion 102 is pushed in while the curved portion 106 is bent and operated to guide the distal end of the endoscope insertion portion 102 toward the pylorus 202, while ensuring the field of view using the observation window and the lighting window at the distal end of the endoscope insertion portion 102.

[0139] (Step S24: Step of passing the outer tube through the pylorus)

[0140] Then, if Figure 8As shown in FIG. VIIIB, the overtube 10 is pressed to pass through the pylorus 202. At this time, since the second region T2 of the overtube 10 in the softened state is configured as a softer region than the first region T1, even if the overtube 10 is pressed in along the endoscope insertion portion 102 that has passed through the pylorus 202, it will not be caught by wrinkles or the like generated on the curved portion 106 of the endoscope insertion portion 102, and the overtube 10 can be smoothly pressed in following the wall surface of the digestive tract (see FIG. VIIIB). Figure 4 ).

[0141] (Step S26: Positioning Step)

[0142] Next, the end portion 104 of the endoscope insertion portion 102 is aligned at a position where it is exposed from the front end of the overtube 10. This alignment is performed by moving the endoscope insertion portion 102 in the base end direction C2 (proximal side) relative to the overtube 10 or by moving the overtube 10 in the front end direction C1 (distal side) relative to the endoscope insertion portion 102. In addition, in the step of passing the overtube through the pylorus, if the alignment of the front end of the overtube 10 and the end portion 104 of the endoscope insertion portion 102 has been completed, the alignment step can be omitted. Furthermore, when the endoscope insertion portion 102 is inserted into a deep part (duodenum) in the body, the alignment step does not necessarily have to be performed.

[0143] (Step S28: Introduction Step)

[0144] Then, if Figure 8 As shown in FIG. VIIIC, the endoscope insertion portion 102 is introduced together with the overtube 10, and a part of the overtube 10 is moved toward the lesser curvature 204 to reduce the slack of the overtube 10. Thus, as in the first example described above, the slack of the overtube 10 inside the stomach 200 is eliminated (stretched) compared to before the insertion step.

[0145] (Step S30: Curing Step)

[0146] Next, the outer tube 10 is cured. Specifically, the pump 26 is operated to discharge the air in the tube internal space S through the supply and discharge port 22. Thus, similarly to the first example described above, when the air in the tube internal space S is discharged through the supply and discharge port 22, the first region T1 becomes a cured state, and the second region T2 located at a position closer to the front end side than the first region T1 becomes a softer state than the cured state of the first region T1. Thus, the endoscope insertion portion 102 can be maintained in a stable state without shaking in the body through the first region T1, and the endoscope insertion portion 102 can be guided to a desired direction through the second region T2. ​​As a result, the insertability of the endoscope insertion portion 102 is improved.

[0147] (Step S32: Insertion Step)

[0148] Then, if Figure 8 As shown in FIG. VIIID, the endoscope insertion portion 102 is pushed relative to the overtube 10, and the endoscope insertion portion 102 is inserted deep into the body.

[0149] Then, the curved portion 106 of the endoscope insertion portion 102 is protruded forward from the front end opening of the outer tube 10, and the treatment tool (not shown) is led forward from the treatment tool lead-out port of the front end portion 104, thereby starting treatment such as ESD (Endoscopic Submucosal Dissection). At this time, since the insertability of the endoscope insertion portion 102 is improved by the outer tube 10 in a solidified state, the front end portion 104 can be located at a correct treatment position, and as a result, the site to be treated (lesion, etc.) can be treated correctly.

[0150] As described above, according to the first embodiment, the outer tube 10 includes: the first region T1, which can be switched between a softened state (first state) in which air is supplied to the tube internal space S between the outer tube 30 and the inner tube 32 via the supply and discharge port 22, and a state harder than the softened state, that is, a solidified state (second state) in which air is discharged from the tube internal space S; and the second region T2, which is located at a position closer to the front end side than the first region T1 and is configured to be softer than the solidified state of the first region T1. Thus, when the first region T1 is set to the solidified state, the endoscope insertion portion 102 can be kept in a stable state in the body by the first region T1, and a sufficient bending amount can be obtained without significantly hindering the bending action of the endoscope insertion portion 102 due to the second region T2.

[0151] Furthermore, according to the first embodiment, in the above-mentioned structure, the softened state of the second region T2 is further configured to be softer than the softened state of the first region T1. Thus, even when the bending amount of the endoscope insertion portion 102 led out from the front end of the overtube 10 in the softened state is large, the overtube 10 can be smoothly pressed in following the wall surface of the digestive tract without being affected by wrinkles or the like generated on the curved portion 106 of the endoscope insertion portion 102.

[0152] Therefore, according to the first embodiment, the insertability of the front end side of the overtube 10 to the digestive tract (especially the upper digestive tract) is improved. As a result, the endoscope insertion part 102 and the overtube 10 can be easily moved in the body, and the endoscope insertion part 102 can be easily and stably guided to a desired direction using the overtube 10. In particular, the above-mentioned effect becomes significant when performing the above-mentioned pylorus passing technique.

[0153] [Second embodiment]

[0154] Fig. 9 It is a schematic cross-sectional view showing the structure of an overtube 10 according to the second embodiment. Fig.10 FIG. 2 is a diagram showing a sheet 50 provided in the outer sleeve 10 of the second embodiment unfolded into a planar shape. Fig.10 The lower stage of FIG. 1 is a graph showing the hardness of the outer tube 10 in the second embodiment. Fig.11 This is an external view in which the outer tube 30 is omitted from the overtube 10 of the second embodiment.

[0155] The overtube 10 of the second embodiment is the same as the first embodiment except for the arrangement and shape of the sheet 50. The configuration different from the first embodiment will be described below.

[0156] like Fig. 9 As shown, in the second embodiment, the sheet 50 is disposed on both the first region T1 and the second region T2 of the outer tube 10. In the sheet 50, the second region T2 is configured as a region softer than the first region T1, and thus has different shapes in the first region T1 and the second region T2.

[0157] Specifically, if Fig.10 and Fig.11 As shown in FIG. 1 , the area corresponding to the first area T1 in the sheet 50 is formed into a sheet shape by a smooth surface without a cutout 52, while a plurality of cutouts 52 are provided in the area corresponding to the second area T2. In this example, most of the cutouts 52 provided in the area corresponding to the second area T2 are formed by a plurality of cutouts 52 extending in the circumferential direction ( Fig.10 The remaining cutout portion 52 is composed of a circular cutout hole.

[0158] In addition, all or part of each cutout portion 52 may be formed by cutting along the direction of the long axis C ( Fig.10 The cutouts 52 may be formed of elongated cutouts in the horizontal direction of the cutouts 52, or may be formed of circular or elliptical cutouts. Furthermore, each cutout portion 52 may also be formed of cutouts in other shapes. Each cutout portion 52 may be formed of Fig.10 Although holes of a plurality of shapes are mixed as in the illustrated example, the structure may be composed of holes of a single shape only.

[0159] like Fig.10 As shown, when the sheet 50 is unfolded into a plane, the plurality of cutouts 52 are arranged in a regular pattern in a top view. Specifically, a plurality of cutout columns 54 composed of a plurality of cutouts 52 arranged at equal intervals in the circumferential direction are arranged at equal intervals along the length direction of the sheet 50 (in the direction of the long axis C), and the cutout columns 54 arranged in the length direction of the sheet 50 are arranged in a staggered manner in a different manner from each other in a state where they are staggered from each other in the circumferential direction.

[0160] In addition, as long as the second region T2 of the outer sleeve 10 can be configured as a softer region than the first region T1, the shape and configuration of each cutout portion 52 provided in the region corresponding to the first region T1 of the sheet 50 are not limited to this example. Moreover, at least a portion, most of, substantially all or all of the plurality of cutout portions 52 may be arranged in a random pattern or an irregular pattern, not limited to a regular pattern as in this example. In addition, a "regular pattern" means that the spacing in the circumferential direction and the spacing in the longitudinal direction (along the direction of the major axis C) of each cutout portion 52 are respectively regular, and of course includes the case where each spacing is equally spaced, and also includes the case where each spacing changes periodically even if it changes. Therefore, even if the shape or size of a part of each cutout portion 52 is different, as long as each spacing is regular, it is also included in the regular pattern.

[0161] According to the second embodiment, a plurality of cutouts 52 are provided in the area corresponding to the second area T2 in the sheet 50. Fig.10 As shown in the lower graph of , the second region T2 of the overtube 12 is configured as a region that is softer than the first region T1. Thus, as in the first embodiment, the overtube 10 and the endoscope insertion portion 102 can be easily moved in the body. As a result, the overtube 10 can be used to easily and stably guide the endoscope insertion portion 102 to a desired direction.

[0162] In the second embodiment, since the above-mentioned notch rows 54 are arranged at equal intervals along the length direction of the sheet 50 (along the direction of the long axis C), the area corresponding to the first area T1 in the sheet 50 has constant softness along the length direction of the sheet 50. In addition, in this specification, "constant" does not mean completely constant, but means substantially constant (for example, a variation within a range of plus or minus 10% is allowed.).

[0163] [Variation of the Second Embodiment]

[0164] Hereinafter, a modification of the second embodiment will be described.

[0165] <First Modification>

[0166] Fig.12 FIG. 5 is a diagram showing the sheet 50A according to the first modification example unfolded into a plane. Fig.12As shown, in the first modified example, each cutout 52A of the sheet 50A provided in the second region T2 of the outer sleeve 10 is composed of cutout lines provided in the circumferential direction. Each cutout 52A is arranged in the same regular pattern as in the second embodiment. That is, a plurality of cutout columns 54A composed of a plurality of cutouts 52A arranged at equal intervals in the circumferential direction are arranged at equal intervals along the length direction of the sheet 50A (in the direction of the major axis C), and the cutout columns 54A arranged in the length direction of the sheet 50A are arranged in a staggered manner in a different manner in a state where they are staggered from each other in the circumferential direction.

[0167] According to the cutout portion 52A of the first modified example, the second region T2 of the overtube 10 can be configured as a region that is softer than the first region T1, and the same effects as those of the second embodiment can be obtained.

[0168] <Second Modification>

[0169] Fig.13 FIG. 5 is a diagram showing a sheet 50B according to the second modification example unfolded into a plane. Fig.13 As shown in FIG. 1 , in the second modification, each cutout 52B of the sheet 50B provided in the second region T2 of the outer sleeve 10 is formed by a cutout line having a shape different from that of the first modification. The cutout line constituting the cutout 52B of the second modification is formed by combining straight lines or curves in multiple directions. As an example, the cutout lines provided in the circumferential direction ( Fig.13 The cutout portion 52B in the central portion in the longitudinal direction of the base end ( Fig.13 The cutout portion array 54B is formed by a plurality of cutout portions 52B arranged at equal intervals in the circumferential direction and is arranged at equal intervals in the longitudinal direction (the direction along the long axis C) of the sheet 50B.

[0170] According to the cutout portion 52B of the second modification, the second region T2 of the overtube 10 can be configured as a region that is softer than the first region T1, and the same effects as those of the second embodiment can be obtained.

[0171] <Third Modification>

[0172] Fig.14 FIG. 5 is a diagram showing a sheet 50C according to the third modification example unfolded into a plane. Fig.14 As shown, in the third modification, the sheet 50C is divided into two different sheets: a first divided sheet 56A arranged in the first area T1 and a second divided sheet 56B arranged in the second area T2. In this way, the sheet 50C can be composed of a plurality of divided sheets divided for each area.

[0173] The cutout 52C and the cutout row 54C of the third modification are the same as the cutout 52 and the cutout row 54 of the second embodiment. The sheet materials of other modifications may also be composed of a plurality of divided sheets as in the third modification.

[0174] <Fourth Modification>

[0175] Fig.15 4 is a diagram showing a sheet 50D according to the fourth modification example unfolded into a plane. Fig.15 The lower part of FIG. 1 is a graph showing the hardness of the outer sleeve 10 in the fourth modified example.

[0176] exist Fig.15 In the fourth modification shown, a plurality of cutouts 52D provided in the second region T2 of the sheet 50D have the same shape as the cutouts 52 of the second embodiment.

[0177] In the fourth modification, a plurality of notch columns 54D composed of a plurality of notch portions 52D arranged at equal intervals in the circumferential direction are arranged in the longitudinal direction (along the long axis C) of the sheet 50D, and the intervals between the notch columns 54D in the longitudinal direction of the sheet 50D, i.e., the spacing P, gradually decreases toward the front end direction C1. Therefore, the area of ​​the sheet 50D corresponding to the second area T2 gradually becomes softer as it moves toward the front end direction C1. As a result, Fig.15 As shown in the lower graph of , the second region T2 of the overtube 10 is configured as a region (gradually changing region) that is softer than the first region T1 and becomes gradually softer toward the distal direction C1.

[0178] Furthermore, the length of the second region T2 of the outer tube 10 in the longitudinal direction (the direction along the long axis C) is preferably 5 cm or more and 50 cm or less. Furthermore, the base end of the second region T2 is preferably provided at a position within 50 cm from the front end of the outer tube 10. In addition, in the fifth and sixth modified examples described later, the same length and position are also preferred.

[0179] According to the fourth modified example, the second region T2 of the overtube 10 gradually becomes softer as it moves toward the front end direction C1, and the front end side of the second region T2 is configured to be softer than the base end side of the second region T2. ​​Thus, when the overtube 10 is in a softened state, the overtube 10 can be easily and smoothly pressed into the endoscope insertion portion 102, compared with a case where the second region T2 has constant softness in the longitudinal direction.

[0180] In addition, regarding the cutout portion 52D of the fourth modified example, the case where the cutout portion 52A of the second embodiment is applied is shown as an example, but the present invention is not limited to this, and other modified examples may be applied as a matter of course.

[0181] <Fifth Modification>

[0182] Fig.16 5 is a diagram showing a sheet 50E according to the fifth modification example unfolded into a plane. Fig.16 The lower part of FIG. 1 is a graph showing the hardness of the outer sleeve 10 in the fifth modified example.

[0183] exist Fig.16 In the fifth modification shown, a plurality of cutouts 52E provided in the second region T2 of the sheet 50E have the same shape as the cutouts 52 of the second embodiment.

[0184] In the fifth modification, the area corresponding to the second area T2 in the sheet 50E is divided into a plurality of (two in this example) areas having different hardnesses. Specifically, the area corresponding to the second area T2 of the sheet 50E includes a front end area R1 (equivalent to the "first intermediate layer" of the present invention) provided on the front end side and a base end area R2 (equivalent to the "second intermediate layer" of the present invention) provided on the base end side.

[0185] A plurality of cutouts 52E are provided in the front end region R1 and the base end region R2, respectively. Furthermore, in each region, the spacing of the cutout columns 54E in the length direction (along the direction of the major axis C) is constant, and in contrast, the spacing Pa of the cutout columns 54E in the front end region R1 is smaller than the spacing Pb of the cutout columns 54E in the base end region R2. Therefore, in the region of the sheet 50E corresponding to the second region T2, the front end region R1 is softer than the base end region R2. Thus, as Fig.16 As shown in the lower graph of , the second region T2 of the overtube 10 is configured as a region that is softer than the first region T1 and in which the distal end side is softer than the proximal end side.

[0186] According to the fifth modification, the front end side of the second region T2 is configured to be softer than the base end side. Thus, similarly to the fourth modification, when the overtube 10 is in a softened state, the overtube 10 can be easily and smoothly pressed into the endoscope insertion portion 102 compared to when the second region T2 has a constant hardness in the longitudinal direction.

[0187] In the fifth modification, the distal region R1 and the proximal region R2 in the second region T2 may be formed of sheets (divided sheets) having different hardnesses. This also applies to the sixth modification described below.

[0188] Furthermore, in the fifth modification, the hardness of the second region T2 in the outer sleeve 10 is changed in two stages, but the present invention is not limited thereto and may be changed in a plurality of stages as in the sixth modification described later.

[0189] <Sixth Modification>

[0190] Fig.17 5 is a diagram showing a sheet 50F according to the sixth modification example unfolded into a plane. Fig.17 The lower part of FIG. 1 is a graph showing the hardness of the outer sleeve 10 in the sixth modified example.

[0191] exist Fig.17 In the sixth modification shown, a plurality of cutouts 52F provided in the second region T2 of the sheet 50F have the same shape as the cutouts 52 of the second embodiment.

[0192] In the sixth modification, a plurality of (five in this example) notch columns 54F constitute a notch group 58. In each notch group 58, the spacing P1 of each notch column 54F is constant, whereas the spacing P2 between each notch group 58 gradually decreases toward the front end direction C1. Therefore, the area corresponding to the second area T2 of the sheet 50F gradually becomes softer in a step-like manner toward the front end direction C1. As a result, Fig.17 As shown in the lower graph of , the second region T2 of the overtube 10 is configured as a region (step-shaped change region) that is softer than the first region T1 and becomes softer in a step-like manner toward the distal direction C1.

[0193] According to the sixth modification, the second region T2 of the overtube 10 gradually becomes soft in a step-like manner as it moves toward the front end direction C1, and the front end side of the second region T2 is configured to be softer than the base end side. Thus, similarly to the fourth modification, when the overtube 10 is in a softened state, the overtube 10 can be easily and smoothly pressed into the endoscope insertion portion 102, compared with the case where the second region T2 has a constant hardness in the longitudinal direction.

[0194] [Bending evaluation of outer sleeve]

[0195] Next, the results of evaluating the degree of bending of the outer tube are described. In this evaluation, the difference in the bending amount of the outer tube when the endoscope insertion part is bent in a state where the endoscope insertion part is inserted into the outer tube and the front end of the endoscope insertion part is roughly aligned with the front end of the outer tube (the bending portion of the endoscope insertion part overlaps the outer tube) is evaluated.

[0196] Fig.18 : is a graph showing the evaluation results of the bending degree of the outer sleeve. Fig.18In the table, "Example 1", "Example 2" and "Example 3" in the first to third columns, excluding the item column, are evaluated using the respective outer sleeves of the first embodiment, the second embodiment and the first variant. The "Comparative Example" in the fourth column corresponds to the above-mentioned prior art, and is formed by arranging a sheet of a smooth surface without a cutout portion over the entire length direction of the tube body constituting the outer sleeve (i.e., arranging the sheet in the first region T1 and the second region T2 so that the hardness of the first region T1 and the second region T2 are the same). In addition, the "Endoscope" in the fifth column shows the results when the insertion portion of the endoscope used in each evaluation is bent alone as a reference. In addition, the outer sleeve used in this evaluation is an outer sleeve in a state where the outer tube is removed for the convenience of evaluation.

[0197] like Fig.18 As shown in the figure, in the "Comparative Example", the bending amount of the outer tube is smaller than the bending amount when the endoscope insertion portion is bent alone. This is because even if the endoscope insertion portion is bent, it will be restricted by the sheet material arranged in the area corresponding to the second area T2, so that the outer tube will not be fully bent.

[0198] In contrast, in Example 1, the bending amount of the outer tube is larger than that of the comparison example, and a bending amount approximately the same as that of bending the endoscope insertion portion alone can be obtained, confirming the effectiveness of the structure in which no sheet is provided in the area corresponding to the second area T2.

[0199] Furthermore, the outer sleeve of "Example 2" can also obtain a bending amount substantially the same as that of "Example 1", confirming the effectiveness of the structure of providing a plurality of cutouts in the region corresponding to the second region T2 of the sheet.

[0200] In addition, regarding the outer sleeve of "Example 3", the cutout portion provided in the sheet material is formed by a shape (cutout line) different from that of "Example 2". In "Example 3", although the bending amount of the outer sleeve is smaller than that of "Example 1" and "Example 2", the bending amount is larger than that of "Comparative Example", and it is confirmed that a certain effect can be obtained in "Example 3".

[0201] Fig.19 This is a graph showing the results of measuring the hardness of the second region T2 of the outer sleeve. As a measurement method, a force gauge was used to measure the hardness (bending rigidity) of the outer sleeve when the front end of the outer sleeve was pressed 25 mm in a direction perpendicular to the length direction (along the direction of the long axis C) with a position 70 mm away from the front end of the outer sleeve as a fulcrum. Fig.19 In the examples 1, 2, 3 and 1, the same Fig.18 The evaluation results shown are the same as for the outer sleeve.

[0202] according to Fig.19 The evaluation results shown show that the bending rigidity of the outer sleeve in the "Comparative Example" is 2N (Newton, the same below), while the bending rigidity of the outer sleeve in the "Example 1" is 0.56N, and in the "Example 2" is 0.61N. And in the "Example 3" is 0.9N.

[0203] Thus, in Example 1 and Example 2, it was confirmed that the bending rigidity of the second region T2 was reduced by about 1 / 4 compared with the Comparative Example, and a sufficient effect could be obtained. In Example 3, it was also confirmed that the bending rigidity of the second region T2 was reduced by about 1 / 2 compared with the Comparative Example, and a certain effect could be obtained.

[0204] 〔Effect〕

[0205] As described above, according to each embodiment (including modified examples, the same below), the hardness of the overtube 10 is variable between a solidified state and a softened state, and in either state, the second region T2 of the overtube 10 is configured as a region that is softer than the first region T1. As a result, the insertability of the front end side of the overtube 10 relative to the digestive tract (especially the upper digestive tract) is improved. As a result, the overtube 10 and the endoscope insertion portion 102 can be easily moved in the body, and the overtube 10 can be used to easily and stably guide the endoscope insertion portion 102 to a desired direction.

[0206] 〔other〕

[0207] In the above-mentioned embodiments, as one of the preferred modes, the sheet materials 40, 50 (including 50A to 50F, the same below) are shown to be present between the outer tube 30 and the shape-adjustable body 38, but the present invention is not limited thereto, and the sheet materials 40, 50 can be placed between the outer tube 30 and the inner tube 32 at a position where the sheet materials 40, 50 (including 50A to 50F, the same below) can be placed in contact with the shape-adjustable body 38. For example, the sheet materials 40, 50 can be placed between the outer tube 30 and the inner tube 32 at a position where the sheet materials 40, 50 (including 50A to 50F, the same below) can be placed between the outer tube 30 and the inner tube 32. Fig. 20 As in another structural example of the outer sleeve 10 of the first embodiment shown in FIG. 1 , a sheet 40 is provided between the inner tube 32 and the shape-adjustable body 38. In this case, at least a portion of at least one of the mutually opposing contact surfaces of the inner tube 32 and the shape-adjustable body 38 is formed of a high friction surface.

[0208] Furthermore, in each of the above-mentioned embodiments, the intermediate layer provided between the outer tube 30 and the inner tube 32 is constituted by the sheets 40 and 50, but the present invention is not limited thereto and the intermediate layer may be constituted by a linear member, etc. Furthermore, the sheets 40 and 50 are not limited to being formed into a cylindrical shape by one sheet, and for example, may be constituted by a cylindrical body having a C-shaped cross section perpendicular to the long axis C, or may be a plurality of long strips of sheets arranged in the circumferential direction and elongated in the direction along the long axis C.

[0209] Furthermore, in each of the above-mentioned embodiments, the second region T2 is configured as a region softer than the first region T1 by making the structures (arrangements or shapes) of the sheets 40 and 50 provided in the outer sleeve 10 different in the first region T1 and the second region T2, but in addition to or instead of this, the winding pitch (pitch) of the belt-shaped member of the spiral tube constituting the shape-adjustable body 38 may be different in the first region T1 and the second region T2. ​​In this case, the second region T2 of the outer sleeve 10 can also be configured as a region softer than the first region T1.

[0210] Furthermore, in each of the above-mentioned embodiments, as a preferred mode, the shape-adjustable body 38 is shown to be composed of a spiral tube, but it is not limited thereto, and any known structure can be applied as long as it can deform along with the shape of the outer sleeve 10. For example, the joint ring component disclosed in the above-mentioned Japanese Patent Document 1 can also be applied as the shape-adjustable body 38. In addition, the joint ring component is well-known, so a detailed description is omitted here.

[0211] Furthermore, in the above-described embodiments, the endoscope insertion portion 102 is used as an example of a medical instrument guided by the overtube of the present invention, but the present invention is not limited thereto and may be applied to a medical treatment instrument such as a manipulator, for example.

[0212] As mentioned above, although the example of the overtube concerning this invention was demonstrated, this invention can make several improvements or modifications within the range which does not deviate from the meaning of this invention.

[0213] Explanation of symbols

[0214] 1-endoscope device, 10-outer tube, 10a-front end, 10b-base end, 14-insertion passage, 16-tube outer peripheral wall, 18-front end cover, 20-base end cover, 22-supply and discharge port, 24-fluid supply and discharge tube, 26-pump, 30-outer tube, 32-inner tube, 38-shape variable body, 40-sheet, 50-sheet, 50A-sheet, 50B-sheet, 50C-sheet, 50D-sheet, 50E-sheet, 50F-sheet, 52-incision portion, 52A-incision portion, 52B-incision portion, 52C-incision portion, 52D-incision portion, 52E-incision portion, 52F-incision portion, 54A-incision portion array, 54B-incision portion array, 54C-incision portion Column, 54D-incision column, 54E-incision column, 54F-incision column, 56A-first divided sheet, 56B-second divided sheet, 58-incision group, 100-endoscope, 102-endoscope insertion part, 104-front end portion, 104a-front end surface, 106-bend portion, 108-soft portion, 110-handheld operation portion, 200-stomach, 202-pylorus, 204-lesser curvature, C-long axis, C1-front end direction, C2-base end direction, T1-first region, T2-second region, P-pitch, Pa-pitch, Pb-pitch, P1-pitch, P2-pitch, R1-front end side region, R2-base end side region, S-space (internal space of the tube).

Claims

1. An outer sleeve having an insertion passage through which a medical device can be inserted, the outer sleeve comprising: a supply and discharge port, located at the base end side and used for supplying and discharging fluid; a first region located closer to the front end side than the supply and discharge port and including a flexible outer tube, a flexible inner tube, and a deformable shape-changing body provided between the outer tube and the inner tube; and The second region is located closer to the front end than the first region and includes the outer tube and the inner tube. The first region can be switched between a first state in which the fluid is supplied to the space between the outer tube and the inner tube via the supply and discharge port and a second state in which the fluid is discharged and is harder than the first state. The second region is softer than the first region in the second state.

2. The outer sleeve according to claim 1, wherein: The second region is softer than the first region in the first state.

3. The outer sleeve according to claim 2, wherein: The distal end side of the second region is softer than the proximal end side of the second region.

4. The outer sleeve according to claim 1, wherein: The second region includes the shape-variable body, The second region is switchable between the first state in which a fluid is supplied to a space between the outer tube and the inner tube via the supply and discharge port and the second state in which the fluid is discharged.

5. The outer sleeve according to claim 4, wherein: The first state of the second region is softer than the first state of the first region, The second state of the second region is softer than the second state of the first region.

6. The outer sleeve according to claim 1, wherein: The first region is disposed between the outer tube and the inner tube and has an intermediate layer capable of contacting the shape-adjustable body. In the second state, the first region becomes hard due to the first contact surface provided on the shape-adaptable body contacting the second contact surface provided on the intermediate layer and facing the first contact surface.

7. The outer sleeve according to claim 6, wherein: The second region includes the intermediate layer having a structure different from that of the intermediate layer in the first region.

8. The outer sleeve according to claim 7, wherein: The intermediate layer in the second region has constant softness along the longitudinal direction.

9. The outer sleeve according to claim 7, wherein: The distal end side of the intermediate layer in the second region is softer than the proximal end side.

10. The outer sleeve according to claim 9, wherein: The intermediate layer in the second region includes a first intermediate layer provided on the distal end side and a second intermediate layer provided on the proximal end side. The first intermediate layer is softer than the second intermediate layer.

11. The outer sleeve according to claim 9, wherein: The intermediate layer in the second region gradually becomes softer toward the front end side.

12. The outer sleeve according to claim 7, wherein: The intermediate layer is composed of a sheet material arranged from the first region to the second region. A cutout portion is provided in the sheet in the second region.

13. The outer sleeve according to claim 12, wherein: The sheet material in the first region is formed of a smooth surface.

14. The outer sleeve according to any one of claims 6 to 13, wherein: At least a portion of any one of the first contact surface and the second contact surface includes a high friction surface.

15. The outer sleeve according to any one of claims 6 to 13, wherein: The middle layer is disposed between the outer tube and the shape-variable body.

16. The outer sleeve according to any one of claims 1 to 13, wherein: The shape-adaptable body includes a spiral tube formed by spirally winding a belt-shaped member around the outer circumference of the inner tube.

17. The outer sleeve according to any one of claims 1 to 13, wherein: The length of the second region in the longitudinal direction is not less than 5 cm and not more than 20 cm, The base end of the second region is disposed within 20 cm from the front end.

18. The outer sleeve according to any one of claims 1 to 13, wherein: The length of the first region in the longitudinal direction is longer than that of the second region.

19. The outer sleeve according to claim 18, wherein: The length of the first region in the longitudinal direction is 20 cm or more.

20. The outer sleeve according to any one of claims 3, 9 to 11, wherein: The length of the second region in the longitudinal direction is not less than 5 cm and not more than 50 cm, and the base end of the second region is provided within 50 cm from the front end.

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