Treatment implement for endoscopes

Abstract

This treatment implement for endoscopes is provided with a sheath, an electroconductive rod disposed on the distal end side of the sheath, and an insulating member fixed to the distal end of the rod, wherein: the distal end of the rod has a first protrusion extending outward in the radial direction of the rod; the distal end of the rod is fixed in the state of being inserted into the insulating member; the insulating member has a side wall surrounding the outer surface of the distal end of the rod; the insulating member has a second protrusion extending from the inner surface of the side wall toward the outer surface of the rod; the first protrusion is disposed at a position that is closer to the distal end than the second protrusion and overlaps the second protrusion in the axial direction of the rod; and the second protrusion extends continuously over the entire circumference of the side wall.

Description

Endoscopic treatment instrument

[0001] The present disclosure relates to an endoscopic treatment instrument.

[0002] Conventionally, in endoscopic treatments such as ESD (endoscopic submucosal dissection), endoscopic treatment instruments such as high-frequency knives have been used. An operator performs incisions of living tissue using an endoscopic treatment instrument such as a high-frequency knife.

[0003] Patent Document 1 describes an endoscopic treatment instrument in which an insulating tip is provided at the tip of a high-frequency knife. A high-frequency knife with an insulating tip at the tip can reduce the risk of perforation.

[0004] Japanese Patent Application Laid-Open No. 2023-507254

[0005] However, in conventional high-frequency knives described in Patent Document 1 and Patent Document 2, etc., it is desired to securely attach an insulating tip to the high-frequency knife.

[0006] In view of the above circumstances, an object of the present disclosure is to provide an endoscopic treatment instrument in which an insulating tip is securely attached to a high-frequency knife.

[0007] To solve the above problems, the present invention proposes the following means. The endoscopic treatment instrument according to the first aspect of the present disclosure includes a sheath, a conductive rod disposed on the tip side of the sheath, and an insulating member fixed to the tip of the rod. The tip of the rod has a first protrusion extending radially outward of the rod. The tip of the rod is fixed in a state of being inserted into the insulating member. The insulating member has a side wall surrounding the outer surface at the tip of the rod. The insulating member has a second protrusion extending from the inner surface of the side wall toward the outer surface of the rod. The first protrusion is on the tip side of the second protrusion and is disposed at a position overlapping the second protrusion in the axial direction of the rod. The second protrusion extends continuously over the entire circumference of the side wall.

[0008] In the endoscopic treatment instrument of the present disclosure, an insulating tip is securely attached to the high-frequency knife.

[0009] This is an overall diagram of an endoscopic treatment system according to the first embodiment of the present disclosure. This is an overall diagram showing the treatment instrument of the endoscopic treatment system. This is a perspective view of the tip of the treatment instrument. This is a diagram showing the tip of the treatment instrument. Same as above. This is a perspective view of the tip of the treatment instrument as seen from the proximal end. This is a diagram showing part of the assembly method of the treatment instrument. Same as above. This is a diagram showing modified versions of the knife and insulating tip of the treatment instrument. This is a diagram showing modified versions of the electrode of the treatment instrument. This is a diagram showing other modified versions of the electrode and other modified versions of the insulating tip. Same as above. Same as above. This is a diagram showing modified versions of the rod of the knife and modified versions of the first projection of the knife. Same as above. This is a diagram showing modified versions of the first projection. This is a diagram of the tip of a treatment instrument according to the second embodiment of the present disclosure. This is a perspective view showing the knife and insulating tip of the treatment instrument. This is a diagram showing part of the assembly method of the treatment instrument. Same as above. This is a diagram showing modified versions of the knife and insulating tip. Same as above. This is a diagram showing other modified versions of the knife and other modified versions of the insulating tip. Same as above. Same as above. This is a diagram of the tip of a treatment instrument according to the third embodiment of the present disclosure. This is a perspective view showing the knife and insulating tip of the treatment instrument. This is a diagram showing part of the assembly method of the treatment instrument. Same as above.

[0010] (First Embodiment) An endoscopic treatment system 300 according to the first embodiment of this disclosure will be described with reference to Figures 1 to 8. Figure 1 is an overall view of the endoscopic treatment system 300 according to this embodiment.

[0011] [Endoscopic Treatment System 300] As shown in Figure 1, the endoscopic treatment system 300 comprises an endoscope 200 and a treatment instrument 100. The treatment instrument 100 is used by inserting it into the endoscope 200.

[0012] [Endoscope 200] The endoscope 200 is a known flexible endoscope and comprises an insertion section 202 that is inserted into the body from the tip and an operating section 207 attached to the base end of the insertion section 202.

[0013] The insertion section 202 has an imaging section 203, a bending section 204, and a flexible section 205. The imaging section 203, bending section 204, and flexible section 205 are arranged in that order from the tip of the insertion section 202. Inside the insertion section 202, a channel 206 for inserting the treatment instrument 100 is provided. The tip of the insertion section 202 is provided with a tip opening 206a of the channel 206.

[0014] The imaging unit 203 is equipped with an image sensor such as a CCD or CMOS, and is capable of imaging the area to be treated. The imaging unit 203 can image the tip of the treatment instrument 100 when the treatment instrument 100 is protruding from the tip opening 206a of the channel 206.

[0015] The curved portion 204 bends in accordance with the operator's operation of the control unit 207. The flexible portion 205 is a tubular part that is flexible.

[0016] The operating section 207 is connected to the flexible section 205. The operating section 207 includes a grip 208, an input section 209, a base end opening 206b of the channel 206, and a universal cord 210. The grip 208 is the part that is grasped by the operator. The input section 209 receives an input for bending the curved section 204.

[0017] The universal code 210 includes a video signal line for outputting the image captured by the imaging unit 203 to the outside. The video signal line is connected to a display device such as a liquid crystal display via an image processing device equipped with a processor and the like.

[0018] [Treatment Instrument 100] Figure 2 is an overall view of the treatment instrument 100. The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100 is an ESD knife. The treatment instrument 100 comprises a sheath 1, a knife 2, an insulating tip 3, an operating wire 4 (see Figure 4), and an operating unit 5. In the following description, in the longitudinal axis direction (longitudinal direction, axial direction) A of the treatment instrument 100, the side inserted into the patient's body is referred to as the "tip side (distal side) A1", and the side with the operating unit 5 is referred to as the "proximal side (proximal side) A2".

[0019] The sheath 1 is a long, tubular member extending from its tip 1a to its base 1b. The sheath 1 is insertable into the channel 206 of the endoscope 200 and can move forward and backward within the channel 206. As shown in Figure 1, when the sheath 1 is inserted into the channel 206, the tip 1a of the sheath 1 can protrude from and retract from the tip opening 206a of the channel 206.

[0020] Figure 3 is a perspective view of the tip of the treatment instrument 100. The sheath 1 has an outer tube 10 extending in the longitudinal axis direction A, and a tip member 11 provided at the tip of the outer tube 10. The sheath 1 may be formed by integrally molding the outer tube 10 and the tip member 11.

[0021] The tip member 11 is formed in a cylindrical shape. Note that "cylindrical shape" includes not only a strictly cylindrical shape but also a shape that is close to a cylindrical shape. The tip member 11 is preferably formed of an insulating material such as resin. A through hole 12 is formed in the tip member 11.

[0022] The through-hole 12 is provided in the tip member 11 and is a hole that penetrates the tip member 11 in the longitudinal axis direction A. The tip of the through-hole 12 communicates with the first opening 12a formed in the tip surface 14 of the tip member 11. The base end of the through-hole 12 communicates with the internal space 19 of the outer tube 10.

[0023] Figures 4 and 5 show the tip of the treatment instrument 100. The knife (electrode) 2 is a metal component. The knife 2 is made of a material such as stainless steel. The knife 2 is conductive and a high-frequency current is passed through it. The knife 2 has a rod 20, an electrode 21, a connector 22, and a first projection 23.

[0024] The rod (blade, electrode body) 20 is a metal, round bar-shaped component. Note that "round bar-shaped" includes not only strictly round bar shapes but also shapes that are close to round bar shapes. The rod 20 is positioned at the tip A1 of the sheath 1. An operating wire 4 is attached to the base end of the rod 20.

[0025] The rod 20 is inserted through the through hole 12 of the tip member 11 of the sheath 1 along the longitudinal axis A, and is able to protrude and retract from the first opening 12a to the tip side A1. The rod 20 may also be fixed in a position where it protrudes from the first opening 12a to the tip side A1 and cannot move forward or backward.

[0026] The central axis O2 of the rod 20 in the longitudinal axis direction A preferably coincides with the central axis O1 of the sheath 1 in the longitudinal axis direction A. Note that "coincidence" includes not only a strict coincidence but also a near coincidence.

[0027] The first projection 23 is provided on the tip portion 20a of the rod 20 and extends radially outward from the outer circumferential surface of the rod 20 in the radial direction R. The first projection 23 is located inside the insulating tip 3. As shown in Figure 3, the first projection 23 is continuous along the circumferential direction C with respect to the longitudinal axis direction A and is formed in an oval shape when viewed from the longitudinal axis direction A. The first projection 23 may also be formed in an elliptical or rectangular shape when viewed from the longitudinal axis direction A.

[0028] Figure 6 is a perspective view of the tip of the treatment tool 100 as seen from the base end side A2. The electrode (flange, enlarged diameter portion) 21 is connected to the rod 20 and is a disc-shaped conductive member extending radially outward R from the outer circumferential surface of the rod 20. The electrode 21 is fixed to the base end surface 3p of the insulating tip 3. A planar base end surface (back surface) 21b is formed on the base end side A2 of the electrode 21. Note that the electrode 21 may not be provided.

[0029] The connector (connecting member) 22 is a cylindrical metal member. Note that "cylindrical" includes not only strictly cylindrical shapes but also shapes that are close to cylindrical. The connector 22 connects the rod 20 and the operating wire 4.

[0030] As shown in Figure 4, when the knife 2 is advanced relative to the sheath 1, the tip of the connector 22 and the tip member 11 come into contact. This contact between the tip of the connector 22 and the tip member 11 positions the knife 2 at the first position P1, which is the position closest to the tip A1.

[0031] As shown in Figure 5, when the knife 2 is retracted relative to the sheath 1, the base end surface 21b of the electrode 21 and the tip surface 14 of the tip member 11 come into contact. This contact between the base end surface 21b of the electrode 21 and the tip member 11 positions the knife 2 at the second position P2, which is the position closest to the base end A2.

[0032] As the operating wire 4 moves forward and backward, the knife 2 can move back and forth between the second position P2 and the first position P1. Alternatively, the knife 2 may be fixed in a position where it protrudes from the first opening 12a toward the tip side A1 and cannot move back and forth.

[0033] A high-frequency current is supplied to the knife 2 from the operating wire 4, which is connected to the operating unit 5. When a high-frequency current is supplied to the knife 2 from the operating wire 4, the rod 20 and electrode 21 function as monopolar electrodes that output the high-frequency current to biological tissue.

[0034] The insulating tip (insulating member, insulator) 3 is made of an insulating material such as ceramic or resin. The insulating tip 3 is provided distal to the electrode 21 A1 and is fixed to the rod 20.

[0035] The insulating tip 3 is a cylindrical component. Note that "cylindrical" includes not only strictly cylindrical shapes but also shapes that are close to cylindrical. The insulating tip 3, as a standalone component, has an internal space 30. An opening 33 is provided at the base end face 3p of the insulating tip 3, communicating with the internal space 30. The insulating tip 3 is fixed to the tip 20a of a rod 20 inserted into the internal space 30 through the opening 33. Specifically, the rod 20 and the insulating tip 3 are joined so that they cannot rotate or swing relative to each other by filling the internal space 30 with adhesive or wax.

[0036] The insulating tip 3 has a tip wall 30t and a side wall 30s. The side wall 30s is formed in a cylindrical shape. Note that "cylindrical shape" includes not only a strictly cylindrical shape but also a shape that is close to a cylindrical shape. When assembled, the side wall 30s extends along the circumferential direction C and surrounds the outer surface of the tip portion 20a of the rod 20. The side wall 30s has an inner surface 30a. The tip wall 30t is formed in a disc shape and is provided at the tip of the insulating tip 3. Note that "disc shape" includes not only a strictly disc shape but also a shape that is close to a disc shape. The tip wall 30t is connected to the tip of the side wall 30s. A base end surface 30b is formed at the base end of the tip wall 30t. Before the rod 20 and the insulating tip 3 are completely fixed with adhesive or wax, an internal space 30 is formed as a cavity between the base end surface 30b, the inner surface 30a, and the tip portion 20a of the rod 20.

[0037] The central axis O3 of the insulating tip 3 in the longitudinal axis direction A preferably coincides with the central axis O1 of the sheath 1 in the longitudinal axis direction A. Note that "coincidence" includes not only a strict coincidence but also a near coincidence.

[0038] The base end face 3p of the insulating tip 3 is fixed to the rod 20 in contact with the electrode 21. As shown in Figure 6, the opening 33 is closed by the electrode 21 fixed to the base end face 3p of the insulating tip 3. If the electrode 21 is not provided, the opening 33 is closed by adhesive or wax filled into the internal space 30 of the insulating tip 3.

[0039] As shown in Figures 4 and 5, a second projection 34 extending radially inward R is provided on the side wall 30s of the internal space 30 of the insulating tip 3. The second projection 34 extends toward the outer surface of the rod 20. The second projection 34 is located on the base end A2 side of the first projection 23 and is spaced apart from the first projection 23 with a gap between them. The second projection 34 may be in contact with the first projection 23, or it may be sandwiched between the first projection 23 and the electrode 21.

[0040] As shown in Figure 3, the second projection 34 extends continuously around the entire circumference of the side wall 30s of the insulating tip 3. The second projection 34 is positioned to overlap with the first projection 23 in the axial direction A. In this embodiment, the second projection 34 forms the edge of the opening 33.

[0041] Figures 7 and 8 show a part of the assembly method of the treatment tool 100. The opening 33 is provided on the base end face 3p of the insulating tip 3 and is formed in the shape of an elongated hole centered on the central axis O3. The edge of the opening 33 is formed by a thick-walled portion 34a and a thin-walled portion 34b of different thicknesses in the radial direction R of the rod 20. The amount of protrusion L1 of the thick-walled portion 34a protruding inward from the side wall 30s in the radial direction R is greater than the amount of protrusion L2 of the thin-walled portion 34b protruding inward from the side wall 30s in the radial direction R (L2 > L1 > 0).

[0042] As shown in Figure 7, the assembler positions the first projection 23 in a first orientation S1 such that the second direction D2, which is the longer radial direction of the oval-shaped first projection 23, coincides with the first direction D1, which is the direction in which the opening width of the elongated hole-shaped opening 33 is larger. The first projection 23 positioned in the first orientation S1 is positioned so as not to overlap with the second projection 34 in the axial direction A. Therefore, the first projection 23 positioned in the first orientation S1 can be inserted through the opening 33. The assembler inserts the tip portion 20a including the first projection 23 positioned in the first orientation S1 through the opening 33 to position the first projection 23 in the internal space 30. The assembler brings the tip 20d of the rod 20 into contact with the base end surface 30b of the tip wall 30t. The first projection 23 and the second projection 34 are positioned with a gap between them. With this configuration, adhesive or wax flows between the first projection 23 and the second projection 34, firmly fixing them in place. It is preferable that the first projection 23 and the base end surface 30b are in contact, but a slight gap between the first projection 23 and the base end surface 30b is also acceptable.

[0043] As shown in FIG. 8, the assembler arranges the first protrusion 23 in the second orientation S2 that is rotated in the circumferential direction C about the central axis O2 from the first orientation S1 in the internal space 30. The first protrusion 23 arranged in the second orientation S2 is arranged at a position overlapping the second protrusion 34 in the axial direction A. Therefore, when trying to pull out the rod 20 from the insulating chip 3, the first protrusion 23 arranged in the second orientation S2 cannot pass through the opening 33 because the first protrusion 23 engages with the edge of the opening 33. Thus, the first protrusion 23 is located on the tip side A1 with respect to the second protrusion 34 and overlaps the second protrusion 34 in the axial direction A. In the present embodiment, it is desirable that the first protrusion 23 be rotated 90 degrees about the central axis O2 in the internal space 30 and arranged from the first orientation S1 to the second orientation S2. This is because the area where the first protrusion 23 and the second protrusion 34 overlap in the axial direction A becomes the largest.

[0044] The assembler joins the rod 20 and the insulating chip 3 by filling the internal space 30 with an adhesive or wax. The rod 20 and the insulating chip 3 are joined by an adhesive or wax, and even if the rod 20 is pulled in the axial direction A, the rod 20 and the insulating chip 3 are joined in a structure where they are caught and do not come off. Therefore, the insulating chip 3 can be more firmly fixed to the rod 20 of the knife 2 than by fixing the insulating chip 3 to the rod 20 of the knife 2 only with an adhesive or wax.

[0045] The second protrusion 34 extends continuously over the entire circumference of the side wall 30s of the insulating chip 3. The second protrusion 34 has higher strength compared to a protrusion that is not continuous over the entire circumference of the side wall 30s of the insulating chip 3. Therefore, the insulating chip 3 is firmly attached to the rod 20 of the knife 2.

[0046] The operating wire 4 is a metal wire that passes through the internal space (pipe, lumen) 19 of the outer tube 10. The operating wire 4 is formed of a material such as stainless steel, for example. The tip of the operating wire 4 is connected to the rod 20, and the base end of the operating wire 4 is connected to the operating portion 5. Note that the operating wire 4 may be a hollow wire. In that case, an opening is provided at the tip of the insulating tip 3, and by connecting the opening and the internal space of the operating wire 4 through a hollow rod 20, a fluid such as physiological saline can be discharged from the tip of the insulating tip 3.

[0047] As shown in FIGS. 1 and 2, the operating portion 5 includes an operating portion main body 51, a slider 52, and a power supply connector 53.

[0048] The tip of the operating portion main body 51 is connected to the base end 1b of the sheath 1. The operating portion main body 51 has an internal space through which the operating wire 4 can pass. The operating wire 4 passes through the internal space 19 of the outer tube 10 and the internal space of the operating portion main body 51 and extends to the slider 52.

[0049] The slider 52 is attached to the operating portion main body 51 so as to be movable along the longitudinal axis direction A. The base end portion of the operating wire 4 is attached to the slider 52. By the operator moving the slider 52 forward and backward relative to the operating portion main body 51, the operating wire 4, the knife 2, and the insulating tip 3 move forward and backward.

[0050] The power supply connector 53 is fixed to the slider 52. The power supply connector 53 can be connected to a high-frequency power supply device (not shown) and is connected to the base end portion of the operating wire 4 via a conductive wire. The power supply connector 53 can supply the high-frequency current supplied from the high-frequency power supply device to the rod 20 via the operating wire 4. Note that the power supply connector 53 may be fixed to the operating portion main body 51 instead of the slider 52.

[0051] According to the treatment instrument 100 according to the present embodiment, the insulating tip 3 is surely attached to the rod 20 of the knife 2.

[0052] Although the first embodiment of this disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and may include design changes and the like that do not depart from the gist of this disclosure. Furthermore, the components shown in the above-described embodiment and modifications can be combined as appropriate.

[0053] (Modification 1) Figure 9 shows knife 2A, which is a modification of knife 2, and insulating tip 3A, which is a modification of insulating tip 3. Knife 2A further has a water supply conduit 28 that penetrates the rod 20. Insulating tip 3A further has a tip opening 35 at its tip. The tip opening 35 communicates with the water supply conduit 28. The surgeon can discharge a fluid such as saline solution, which has been inserted through the water supply conduit 28 from the sheath 1, etc., from the tip opening 35.

[0054] (Modification 2) Figure 10 shows electrode 21A, which is a modification of electrode 21. Electrode 21A is formed in a radial shape, extending radially outward from the central axis O2 of rod 20 in the radial direction R. Electrode 21A illustrated in Figure 10 is formed in a three-pronged shape. The base end face 3p of the insulating tip 3 is fixed to the rod 20 in contact with electrode 21A. The opening 33 is closed by electrode 21A fixed to the base end face 3p of the insulating tip 3.

[0055] (Modification 3) Figures 11 to 13 show a modified electrode 21B, which is a modified electrode 21, and an insulating tip 3B, which is a modified insulating tip 3. The insulating tip 3B further has a recess (second step) 36 on its base end face 3p. The electrode 21B further has a protrusion (first step) 24 on its tip face 21a. The protrusion 24 is engageable with the recess 36. The assembler passes the tip 20a, which includes the first projection 23 positioned in a first orientation S1, through the opening 33, and positions the first projection 23 in the internal space 30. The assembler rotates the rod 20 in the circumferential direction C to engage the protrusion 24 with the recess 36. As a result, the base end face 3p of the insulating tip 3B and the tip face 21a of the electrode 21B are locked in the circumferential direction C and can no longer rotate relative to each other. At this time, the first projection 23 is positioned in a second orientation S2. That is, the first projection 23 is positioned within the insulating tip 3B at a distance from the second projection 34. As a result, the first projection 23 is positioned closer to the tip A1 than the second projection 34, and overlaps with the second projection 34 in the axial direction A. The base end surface 3p of the insulating tip 3B may have a convex portion (second step), and the tip surface 21a of the electrode 21B may have a concave portion (first step). That is, the base end surface 3p of the insulating tip 3B and the tip surface 21a of the electrode 21B should have an engageable step to restrict relative rotation in the circumferential direction C.

[0056] (Modification 4) Figures 14 and 15 show a modified rod 20A, which is a modified rod 20, and a modified first projection member 23A, which is a modified first projection 23. The rod 20A and the first projection member 23A are separate components. The rod 20A has a large diameter portion 20s at the tip A1 and a small diameter portion 20t at the base A2. A step 20u is provided between the large diameter portion 20s and the small diameter portion 20t. The first projection member 23A is formed in an oval shape when viewed from the longitudinal axis direction A. The first projection member 23A may be made of metal, ceramic material, or resin material. The first projection member 23A has a through hole 23h that penetrates in the longitudinal axis direction A. The first projection member 23A is attached to the rod 20A by inserting the small diameter portion 20t through the through hole 23h. The first projection member 23A is positioned to engage with the step 20u. The first projection member 23A and the rod 20A are fixed to each other by welding or the like. The first projection member 23A may also be bonded to the insulating tip 3 with an adhesive or the like. Because the first projection member 23A is mechanically engaged with the step 20u, the insulating tip 3 is more firmly fixed to the rod 20. Furthermore, assembly is easy.

[0057] (Modification 5) Figure 16 shows a modification of the first projection 23, which is a first projection 23B. The first projection 23B extends to the tip of the rod 20. The rod 20 and the first projection 23B may be formed integrally. The first projection 23B and the base end surface 30b are in contact, and the first projection 23B and the second projection 34 are spaced apart with a gap between them. With this configuration, adhesive or wax flows between the first projection 23B and the second projection 34, fixing them firmly in place. It is preferable that the first projection 23B and the base end surface 30b are in contact, but it is also acceptable if the first projection 23B and the base end surface 30b are slightly spaced apart.

[0058] (Second Embodiment) The treatment tool 100C according to the second embodiment of the present disclosure will be described with reference to Figures 17 to 20. In the following description, components that are common to those already described will be denoted by the same reference numerals and redundant descriptions will be omitted.

[0059] The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100C is an ESD knife. The treatment instrument 100C comprises a sheath 1, a knife 2C, an insulating tip 3C, an operating wire 4, and an operating unit 5.

[0060] Figure 17 shows the tip of the treatment instrument 100C. The knife (electrode) 2C is a metal component. The knife 2C is made of a material such as stainless steel. The knife 2C is conductive and a high-frequency current is passed through it. The knife 2C has a rod 20, a connector 22, and a first projection 23C.

[0061] Figure 18 is a perspective view showing the knife 2C and the insulating tip 3C. The first projection 23C is a flange provided on the tip 20d of the rod 20 and extending outward in the radial direction R. The first projection 23C is not continuous along the circumferential direction C, but extends in a part of the radial direction R.

[0062] The insulating tip (insulating member, insulator) 3C is made of an insulating material such as ceramic or resin. The insulating tip 3C is fixed to the rod 20.

[0063] The insulating tip 3C is a cylindrical component. Note that "cylindrical" includes not only strictly cylindrical shapes but also shapes that are close to cylindrical. The insulating tip 3C has an internal space 30. An opening 33C communicating with the internal space 30 is provided at the base end face 3p of the insulating tip 3C. The insulating tip 3C is fixed to the tip 20a of the rod 20, which is inserted into the internal space 30 through the opening 33C. Specifically, the rod 20 and the insulating tip 3C are joined so that they cannot rotate or swing relative to each other by filling the internal space 30 with adhesive or wax.

[0064] As shown in Figure 17, a second projection 34C is provided extending radially inward R from the side wall 30s of the internal space 30 of the insulating tip 3C. The second projection 34C extends toward the outer surface of the rod 20. The second projection 34C is located on the base end A2 side of the first projection 23C and is spaced apart from the first projection 23C with a gap between them.

[0065] As shown in Figure 18, the second projection 34C extends continuously around the entire circumference of the side wall 30s of the insulating tip 3C. The second projection 34C is positioned to overlap with the first projection 23C in the axial direction A. In this embodiment, the second projection 34C forms the edge of the opening 33C.

[0066] The opening 33C is provided on the base end face 3p of the insulating tip 3C and is formed in a circular shape with respect to the central axis O3. The amount by which the second projection 34C protrudes radially inward from the side wall 30s is constant. The width (inner diameter) L4 of the opening 33C is greater than the width (outer diameter) L5 of the rod 20 located inside the opening 33C, and less than the maximum width L3 of the tip 20d of the rod 20 including the first projection 23C (L3 > L4 > L5). The maximum width L3 is the width between the tip 20d in the direction connecting the top 23p of the first projection 23C that protrudes most radially inward and the central axis O2 of the rod 20.

[0067] Figures 19 and 20 show a part of the assembly method of the treatment instrument 100C. As shown in Figure 19, the assembler positions the rod 20 in a first orientation S1 where its longitudinal axis (e.g., central axis O2) is oblique to the longitudinal axis (e.g., central axis O3) of the insulating tip 3C. The first projection 23C positioned in the first orientation S1 is positioned so as not to overlap with the second projection 34C in the axial direction A. Therefore, the first projection 23C positioned in the first orientation S1 can be inserted through the opening 33C. The assembler passes the tip portion 20a, including the first projection 23C positioned in the first orientation S1, through the opening 33C, thereby positioning the first projection 23C in the internal space 30.

[0068] The assembler inserts the tip 20a of the rod 20 into the internal space 30 of the insulating tip 3C, aligns the longitudinal axis direction of the rod 20 with the longitudinal axis direction of the insulating tip 3C, and positions the first projection 23C in the second orientation S2. The first projection 23C positioned in the second orientation S2 is located in a position that overlaps with the second projection 34C in the axial direction A. Therefore, if the assembler attempts to pull the rod 20 out of the insulating tip 3C, the first projection 23C engages with the edge of the opening 33C, making it impossible to insert the rod through the opening 33C. The assembler then brings the tip 20d of the rod 20 into contact with the base end surface 30b of the tip wall 30t. The first projection 23C and the second projection 34C are positioned with a gap between them.

[0069] The assembler fixes the tip 20a of the rod 20 to the insulating tip 3C by filling the internal space 30 with adhesive or wax, while aligning the longitudinal axis direction of the rod 20 with the longitudinal axis direction of the insulating tip 3C. The rod 20 and the insulating tip 3C are joined by adhesive or wax, and the joint is such that even if the rod 20 is pulled in the axial direction A, the rod 20 and the insulating tip 3C will catch and not come apart. Therefore, the insulating tip 3C can be fixed more firmly to the rod 20 of knife 2C than if the insulating tip 3C of knife 2 were fixed to the rod 20 of knife 2 with adhesive or wax alone.

[0070] According to the treatment tool 100C of this embodiment, the insulating tip 3C can be firmly fixed to the rod 20 of the knife 2C.

[0071] Although the second embodiment of this disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and may include design changes and the like that do not depart from the gist of this disclosure. Furthermore, the components shown in the above-described embodiment and modified examples can be combined as appropriate.

[0072] (Modification 2-1) Figures 21 and 22 show a modified knife 2D of knife 2C and an insulating tip 3D of insulating tip 3C. Knife 2D has a rod 20D and a first projection 23D. Rod 20D is a round metal rod-shaped member, and its tip portion 20Da is curved toward the first direction R1 in the radial direction R. Note that the tip portion 20Da does not necessarily have to be curved, and may be a flange shape extending outward in the radial direction R, as in the second embodiment. The first projection 23D is provided on the tip portion 20a of rod 20D and is a projection extending outward in the radial direction R. The first projection 23D is not continuous along the circumferential direction C, but extends in the second direction R2, which is the opposite direction to the first direction R1 in the radial direction R. The first projection 23D extends in a direction different from the curvature direction of tip portion 20Da (or the direction in which the flange extends).

[0073] A second projection 34D is provided on the side wall 30s of the internal space 30 of the insulating chip 3D, extending radially inward in the direction R. The second projection 34D extends continuously around the entire circumference of the side wall 30s of the insulating chip 3D. The second projection 34D forms the edge of the opening 33D. The opening 33D is provided on the base end face 3p of the insulating chip 3D and is formed in a circular shape with an axis eccentric to the central axis O3.

[0074] As shown in Figure 21, the assembler tilts the tip portion 20a, including the first projection 23D, and passes it through the opening 33D, positioning the first projection 23D in the internal space 30. As shown in Figure 22, the assembler positions the first projection 23D in a second orientation S2, rotated in the circumferential direction C around the central axis O2. The tip portion 20Da of the rod 20D is positioned by engaging with the rotation stopper 30c formed on the inner surface 30a.

[0075] (Modification 2-2) Figures 23, 24, and 25 show a modified knife 2E, which is a modified knife 2C, and an insulating tip 3E, which is a modified insulating tip 3C. The knife 2E has a rod 20 and a first projection 23E. The first projection 23E is provided on the tip portion 20a of the rod 20 and is a projection that extends radially outward in the direction R. The second projection 34E extends radially inward from the side wall 30s of the internal space 30 of the insulating tip 3E in the direction R. The second projection 34E extends continuously around the entire circumference of the side wall 30s of the insulating tip 3E. The second projection 34E forms the edge of the opening 33D. The opening 33D is provided on the base end face 3p of the insulating tip 3E and is oriented in a direction inclined from the central axis O3.

[0076] The assembler rotates the tip portion 20a, including the first projection 23E, through the opening 33E, positioning the first projection 23E in the internal space 30 as shown in Figure 25. The assembler rotates the first projection 23E in the circumferential direction C around the central axis O2 while aligning it with the edge of the opening 33D, and moves the rod 20 to the tip side A1, positioning the first projection 23E in a second direction S2 that is different from the first direction S1. The first projection 23E is positioned by engaging with the rotation stopper 30c formed on the inner surface 30a.

[0077] (Third Embodiment) The treatment tool 100F according to the third embodiment of this disclosure will be described with reference to Figures 26 to 29. In the following description, components that are common to those already described will be denoted by the same reference numerals and redundant descriptions will be omitted.

[0078] The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100F is an ESD knife. The treatment instrument 100F comprises a sheath 1, a knife 2F, an insulating tip 3C, an operating wire 4, and an operating unit 5.

[0079] Figure 26 shows the tip of the treatment instrument 100F. The knife (electrode) 2F is a metal component. The knife 2F is made of a material such as stainless steel. The knife 2F is conductive and a high-frequency current is passed through it. The knife 2F has a rod 20F, a connector 22, and a first projection 23F.

[0080] Figure 27 is a perspective view showing the knife 2F and the insulating tip 3C. The rod 20F has an additional slit 25 compared to the rod 20 of the first embodiment. The slit 25 is a groove formed from the tip 20d of the rod 20F toward the base end A1 along the longitudinal axis A. When the rod 20F is attached to the insulating tip 3C, as shown in Figure 29, the base end of the slit 25 is located in the internal space 30 of the insulating tip 3C. It is desirable that the multiple slits 25 are formed evenly along the circumferential direction C.

[0081] The first projection 23F is a flap provided on the tip portion 20a of the rod 20F, extending outward in the radial direction R perpendicular to the longitudinal axis direction A. The first projection 23F is located in the internal space 30 of the insulating tip 3C. The first projection 23F is not continuous along the circumferential direction C, but is provided on both sides of the central axis O2 of the rod 20F. The first projection 23F is provided at a position offset in the circumferential direction C from the position of the slit 25.

[0082] The width (inner diameter) L4 of the opening 33C is greater than the width (outer diameter) L5 of the rod 20F located inside the opening 33C, and less than the maximum width L3 of the tip portion 20a of the rod 20F including the first projection 23F (L3 > L4 > L5). The maximum width L3 is the width between the tip 20d of the first projection 23F, which protrudes most radially R, and the central axis O2 of the rod 20F.

[0083] Figures 28 and 29 show a part of the assembly method of the treatment instrument 100F. As shown in Figure 28, the assembler inserts the tip portion 20a of the rod 20F into the opening 33C to narrow the width of the slit 25, reducing the maximum width L3 to a width L4 or less, thereby positioning the first projection 23F at the first position S1. The first projection 23F positioned at the first position S1 is positioned so as not to overlap with the second projection 34C in the axial direction A. Therefore, the first projection 23F positioned at the first position S1 can pass through the opening 33C. The assembler passes the tip portion 20a, including the first projection 23F positioned at the first position S1, through the opening 33C, thereby positioning the first projection 23F in the internal space 30.

[0084] As shown in Figure 29, the first projection 23F, having passed through the opening 33C, returns to its original position, the second orientation S2, due to the elastic force of the tip portion 20a of the rod 20F. The first projection 23F, positioned in the second position S2, is positioned to overlap with the second projection 34C in the axial direction A. Therefore, when attempting to pull the rod 20F out of the insulating tip 3C, the first projection 23F, positioned in the second position S2, engages with the edge of the opening 33C, making it impossible to insert it through the opening 33C. The assembler brings the tip 20d of the rod 20F into contact with the base end surface 30b of the tip wall 30t. The first projection 23F and the second projection 34C are positioned with a gap between them.

[0085] The assembler joins the rod 20F and the insulating tip 3C by filling the internal space 30 with adhesive or wax. The rod 20F and the insulating tip 3C are joined by adhesive or wax, and the joint is such that even if the rod 20F is pulled in the axial direction A, the rod 20F and the insulating tip 3C will catch and not come apart. Therefore, the insulating tip 3C is firmly fixed to the rod 20F of the knife 2F.

[0086] According to the treatment tool 100F of this embodiment, the insulating tip 3C is securely attached to the rod 20F of the knife 2F.

[0087] Although the third embodiment of this disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and may include design changes and the like that do not depart from the gist of this disclosure. Furthermore, the components shown in the above-described embodiments and modifications can be combined as appropriate.

[0088] This disclosure can be applied to endoscopic instruments.

[0089] 300 Endoscopic Treatment System 200 Endoscope 100, 100C, 100F Treatment Instruments (Endoscopic Treatment Instruments, High-Frequency Treatment Instruments) 1 Sheath 10 Outer Tube 11 Tip Member 12 Through Hole 12a First Opening 14 Tip Face 19 Internal Space (Pipeline, Lumen) 2, 2A, 2C, 2D, 2E, 2F Knife (Electrode) 20, 20A, 20D, 20F Rod (Blade, Electrode Body) 20a, 20Da Tip Section 20d Tip 20s Large Diameter Section 20t Small Diameter Section 20u Step 21, 21A, 21B Electrode (Flange, Enlarged Diameter Section) 21a Tip Face 21b Base End Face (Back) 22 Connector (Connecting Member) 23, 23B, 23C, 23D, 23E, 23F First projection 23A First projection member 23h Through hole 23p Top 24 Convex part 25 Slit 28 Water supply conduit 3, 3A, 3B, 3C, 3D, 3E Insulating tip (insulating member, insulator) 3p Base end face 30 Internal space 30a Inner surface 30b Base end face 30t Tip wall 30s Side wall 33, 33C, 33D, 33E Opening 34, 34C, 34D, 34E Second projection 34a Thick part 34b Thin part 35 Tip opening 36 Recess 4 Operating wire 5 Operating part 51 Operating part body 52 Slider 53 Power supply connector

Claims

1. An endoscopic treatment instrument comprising: a sheath; a conductive rod disposed on the tip side of the sheath; and an insulating member fixed to the tip of the rod, wherein the tip of the rod has a first projection extending radially outward from the rod, the tip of the rod is fixed in an inserted state within the insulating member, the insulating member has a side wall surrounding the outer surface of the tip of the rod, the insulating member has a second projection extending from the inner surface of the side wall toward the outer surface of the rod, the first projection is positioned closer to the tip than the second projection and overlaps with the second projection in the axial direction of the rod, and the second projection extends continuously around the entire circumference of the side wall.

2. The rod and the insulating member are joined together such that the first projection and the second projection are spaced apart with a gap between them, as described in claim 1.

3. The endoscopic treatment instrument according to claim 1, wherein the base end of the insulating member has an opening into which the first projection can be inserted, and the second projection forms the edge of the opening.

4. The endoscopic treatment instrument according to claim 3, wherein the opening is formed on the base end face of the insulating member.

5. The rod and the insulating member are joined by either an adhesive or wax, and the opening is closed by filling with either the adhesive or wax, as described in claim 3.

6. The endoscopic treatment instrument according to claim 4, wherein the rod has an electrode extending radially outward, and the electrode is fixed to the base end face of the insulating member and closes the opening.

7. The rod is fixed to the insulating member by sandwiching the second projection between the first projection and the electrode, as described in claim 6.

8. The rod and the insulating member are joined by filling the space between the first projection and the second projection with adhesive or wax, with a gap between them, as described in claim 1.

9. The endoscopic treatment instrument according to claim 8, wherein the rod and the insulating member are fixed so as not to rotate relative to each other by joining them.

10. The endoscopic treatment instrument according to claim 8, wherein the rod and the insulating member are fixed so as not to swing relative to each other by joining them.

11. The edge of the opening is formed by a thick-walled portion and a thin-walled portion of the rod having different thicknesses in the radial direction, and the position of the thick-walled portion and the position of the first projection coincide in the circumferential direction around the longitudinal axis of the rod, as described in claim 3.

12. The endoscopic treatment instrument according to claim 1 or claim 2, wherein the base end of the insulating member has an opening into which the first projection can be inserted, the first projection is a flange or flap extending radially outward from the rod, the first projection has a maximum width in the direction connecting the top of the first projection and the central axis of the rod, and the width of the opening is greater than the width of the rod and less than the maximum width of the first projection.

13. The endoscopic treatment instrument according to claim 1 or claim 2, wherein the base end of the insulating member has an opening into which the first projection can be inserted, the first projection is a flap extending radially outward from the rod, the rod has a slit extending from the tip of the rod toward the base end, and the flap is provided at a position offset in the circumferential direction from the position of the slit on the rod.

14. The endoscopic treatment instrument according to claim 13, wherein the base end of the slit is located inside the insulating member.

15. The endoscopic treatment instrument according to claim 1, having an electrode attached to the tip of the rod, wherein the electrode extends radially outward from the rod, and when the tip surface of the electrode and the base end surface of the insulating member are locked in the circumferential direction of the rod, the second projection is located on the tip side of the insulating member than the first projection.

16. The endoscopic treatment instrument according to claim 15, wherein the tip surface of the electrode has a first step in the circumferential direction of the rod, the base end surface of the insulating member has a second step in the circumferential direction of the rod, and when the first step and the second step are locked together, the second projection is located on the tip side of the insulating member than the first projection.

17. A method for assembling an endoscopic instrument, comprising: inserting the tip of a conductive rod into the insulating member such that the longitudinal axis of the conductive rod is oblique to the longitudinal axis of the insulating member; aligning the direction of the longitudinal axis of the rod and the longitudinal axis of the insulating member with the tip of the rod inserted into the insulating member; and fixing the rod and the insulating member in a state where the direction of the longitudinal axis of the rod and the longitudinal axis of the insulating member are aligned.

18. The method for assembling an endoscopic treatment instrument according to claim 17, wherein the rod has a first projection extending radially outward, the insulating member has a second projection extending radially inward, and the rod and the insulating member are fixed together with the base end surface of the first projection and the tip surface of the second projection in contact.

19. The method for assembling an endoscopic treatment instrument according to claim 18, wherein the rod has a first projection extending radially outward, the insulating member has a second projection extending radially inward, and the rod and the insulating member are fixed together with a gap between the base end face of the first projection and the tip face of the second projection.

20. An endoscopic treatment instrument comprising: a sheath; a conductive rod disposed on the tip side of the sheath; an insulating member disposed on the distal side of the rod; an electrode attached to the tip of the rod and extending radially outward from the rod; a first projection provided with a gap from the electrode toward the tip and extending radially outward from the rod; and a second projection extending radially inward from the base end of the insulating member, wherein when the tip surface of the electrode and the base end surface of the insulating member are locked in the circumferential direction of the rod, the second projection is located on the tip side of the insulating member than the first projection.

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