Medical tube, endoscope, and method for manufacturing medical tube

Abstract

A medical tube 30 comprises: a tube body 31 including a first spiral layer 35 formed by spirally winding a first wire 35a along a first direction about an axis A, and a second spiral layer 36 disposed on the outer periphery of the first spiral layer 35 and formed by spirally winding a second wire 36a along a second direction that intersects the first direction about the axis A; and a first resin layer 32 that is provided in a gap defined by a pitch P1 of a first wire group 35ag in the first spiral layer 35, and that is provided between the first spiral layer 35 and the second spiral layer 36.

Description

Medical tube, endoscope, and method for manufacturing medical tube

[0001] The present invention relates to a flexible medical tube, an endoscope using the medical tube, and a method for manufacturing a medical tube.

[0002] Conventionally, endoscopes are used for observing a target site inside a subject such as a body cavity, and performing various treatments on the target site as needed. As endoscopes, flexible endoscopes in which an insertion portion includes a distal end portion, a bending portion, and a flexible tube portion are widely used.

[0003] The flexible tube portion of a flexible endoscope is configured using a flexible medical tube. As this type of medical tube, a blade tube formed by braiding metal strands into a cylindrical shape is widely used. Further, for example, Patent Document 1 discloses a flexible portion (medical tube) of an endoscope formed by winding a plurality of layers of metal strands in a spiral shape around the outer circumference of a band-shaped spiral tube. Furthermore, Patent Document 1 discloses a technique of performing diffusion bonding on a metal strand cylindrical body formed by winding metal strands and a band-shaped spiral body, and bonding overlapping portions of each member.

[0004] Japanese Patent No. 6100506

[0005] However, as disclosed in the above-mentioned Patent Document 1, bonding of metal strands or the like using diffusion bonding requires a predetermined time, which may reduce the productivity of medical tubes. On the other hand, in order to maintain appropriate flexibility of a medical tube, it is necessary to suppress displacement of the spirally wound metal strands in the axial direction and radial direction.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a medical tube, an endoscope, and a method for manufacturing a medical tube that are excellent in productivity and can maintain appropriate flexibility performance.

[0007] A medical tube according to one aspect of the present invention includes a tubular body comprising: a first helical layer in which first strands are formed spirally along a first direction around the axis; a second helical layer arranged on the outer circumference of the first helical layer and in which second strands are formed spirally along a second direction intersecting the first direction around the axis; a gap defined by the pitch of the first strands in the first helical layer; and a first resin layer provided between the first helical layer and the second helical layer.

[0008] Furthermore, an endoscope according to one aspect of the present invention includes a medical tube in the insertion section having a tubular body comprising: a first helical layer in which first strands are formed spirally along a first direction around the axis; a second helical layer arranged on the outer circumference of the first helical layer and in which second strands are formed spirally along a second direction intersecting the first direction around the axis; a gap defined by the pitch of the first strands in the first helical layer; and a first resin layer provided between the first helical layer and the second helical layer.

[0009] Furthermore, a method for manufacturing a medical tube according to one aspect of the present invention includes the steps of: forming a first helical layer by winding a first wire along a first direction around the axis of a core material for molding; forming a gap in the first helical layer defined by the pitch of the first wires, and a first resin layer on the outer circumference of the first helical layer; and forming a second helical layer by winding a second wire around the outer circumference of the first resin layer along a second direction intersecting the first direction around the axis.

[0010] According to the present invention, it is possible to achieve excellent productivity while maintaining appropriate flexibility.

[0011] The present invention relates to an embodiment, a perspective view embodiment showing the external appearance of an endoscope, a cross-sectional view embodiment showing the main part of the insertion section along the central axis, a perspective view embodiment showing a medical tube, a cross-sectional view embodiment of IV-IV in Figure 3, a flowchart embodiment showing the manufacturing process of a medical tube, a perspective view embodiment showing the process of forming the first helical layer, a perspective view embodiment showing the process of forming the first helical layer, a perspective view embodiment showing the coating process of the first resin layer, a perspective view embodiment showing the process of forming the second helical layer, a first modified example of the perspective view embodiment showing the process of forming the second helical layer, a first modified example of the perspective view embodiment showing a medical tube, and the present invention relates to the XII- in Figure 11. This relates to a first modification of the cross-sectional view embodiment, a first modification of the flowchart embodiment showing the manufacturing process of a medical tube, a second modification of the perspective view embodiment showing the coating process of the first second resin layer, a third modification of the cross-sectional view embodiment showing the main part of the medical tube along the axial direction, a fourth modification of the cross-sectional view embodiment showing the main part of the medical tube along the axial direction, a fifth modification of the flowchart embodiment showing the manufacturing process of a medical tube, a fifth modification of the cross-sectional view embodiment showing the medical tube along the direction perpendicular to the axis, a fifth modification of the cross-sectional view embodiment showing an enlarged view of the main part of Figure 18, and a cross-sectional view showing an enlarged view of the main part of Figure 18.

[0012] The embodiments of the present invention will now be described with reference to the drawings. The drawings relate to one embodiment of the present invention, and Figure 1 is a perspective view showing the external appearance of the endoscope. In the following description, the drawings based on each embodiment are schematic. It should also be noted that the relationship between the thickness and width of each component of the endoscope, the ratio of the thickness of each component, etc., may differ from those of reality. Furthermore, even among the components of the endoscope shown in the drawings, there may be parts where the dimensional relationships and ratios of each component differ from those of the other.

[0013] The endoscope 1 shown in Figure 1 is, for example, an endoscope for the renal pelvis and urinary tract (renal pelvis ureteroscope). This endoscope 1 is a single-use type in which, for example, all or at least some of the parts of the endoscope 1 are disposed of after a single use. The endoscope 1 comprises an elongated insertion section 2 that is inserted into the body cavity of the subject, an operating section 3 provided at the base end of the insertion section 2, and a universal cable 4 extending from the base end of the operating section 3.

[0014] As shown in Figure 1, the insertion portion 2 has a tip portion 6, a curved portion 7, and a flexible tube portion 8. These tip portion 6, curved portion 7, and flexible tube portion 8 are arranged in order from the tip side of the insertion portion 2.

[0015] The tip portion 6 is provided with an imaging unit 10, an illumination optical system (not shown), and a treatment tool channel opening, etc.

[0016] The curved section 7 is configured to actively curve vertically in response to operational input from the operator or other user to the control unit 3. In this embodiment, the front-rear, left-right, and right directions of the insertion section 2 are defined in relation to the images captured by the imaging unit 10.

[0017] Specifically, the curved section 7 has a set of curved pieces arranged in a row, which are not shown. In this set of curved pieces, adjacent curved pieces are connected by a pair of left and right axes so that they can rotate relative to each other. In addition, a wire guide is provided on a predetermined curved piece. One of a pair of upper and lower traction wires 12 is inserted through each wire guide. Each traction wire 12 is pulled or released in response to an operation input from the operator or others to the operation unit 3. This makes it possible to curve the curved section 7 in the vertical direction.

[0018] Inside the curved frame assembly configured in this way, internal components such as the signal cable 11 extending from the imaging unit 10, the traction wire 12, the light guide 13, and the treatment instrument channel 14 are inserted. The outer circumference of the curved frame assembly is covered with curved rubber.

[0019] As shown in Figure 4, the flexible tube section 8 is constructed using a medical tube 30 (described later) that is flexible and can be bent passively. The medical tube 30 contains internal components such as the signal cable 11, traction wire 12, light guide 13, and treatment instrument channel 14. The outer circumference of the medical tube 30 is covered by an outer sheath 15.

[0020] The operating section 3 includes a bend-stopping section 20, a gripping section 21, and the operating section body 22.

[0021] The anti-folding portion 20 is connected to the flexible pipe portion 8 in a state that it covers the base end of the flexible pipe portion 8.

[0022] The gripping portion 21 is connected to the base end of the anti-folding portion 20. This gripping portion 21 is shaped to be grasped by the hand of a surgeon or other operator.

[0023] A treatment instrument insertion section 23 is provided at the tip of the gripping section 21. The treatment instrument insertion section 23 is configured to have a treatment instrument insertion opening 23a through which various treatment instruments (not shown) can be inserted. Inside the gripping section 21, the base end of the treatment instrument channel 14 is in communication with the treatment instrument insertion opening 23a. Furthermore, a forceps plug (not shown), which is a lid member for closing the treatment instrument insertion opening 23a, is detachably attached to the treatment instrument insertion section 23.

[0024] The operating unit body 22 is connected to the base end of the gripping unit 21. The operating unit body 22 is provided with a bending lever 25. The bending lever 25 is used to bend the bending unit 7 in the vertical direction by pulling or releasing a pair of traction wires 12.

[0025] In other words, for example, when the bending lever 25 is tilted toward the tip of the operating section 3, one of the pair of towing wires 12, the upper towing wire 12, is pulled, and the other towing wire 12, the lower towing wire, is released. As a result, the bending section 7 bends upward. On the other hand, when the bending lever 25 is tilted toward the base end of the operating section 3, one of the pair of towing wires 12, the upper towing wire 12, is released, and the other towing wire 12, the lower towing wire, is pulled. As a result, the bending section 7 bends downward.

[0026] Furthermore, the control unit body 22 is equipped with a group of operation buttons 26 to which various functions of the endoscope 1 are assigned.

[0027] The universal cable 4 extends from the side of the control unit body 22. Various cables, such as the signal cable 11, and the light guide 13 are inserted inside the universal cable 4.

[0028] Furthermore, a connector 5 is provided at the extended end of the universal cable 4. This connector 5 allows various cables and light guides to be connected to the video processor and light source device (neither of which are shown in the illustration).

[0029] Next, the configuration of the medical tube 30 that constitutes the flexible tube portion 8 of the insertion portion 2 will be explained in detail.

[0030] As shown in Figures 3 and 4, the medical tube 30 has a tubular body 31 and a first resin layer 32.

[0031] The tube 31 has a first helical layer 35 and a second helical layer 36. The first helical layer 35 and the second helical layer 36 are composed of a first strand 35a and a second strand 36a, respectively. The first strand 35a and the second strand 36a are composed of, for example, metal strands. The metal strands are preferably made of austenitic stainless steel, iron, or copper. However, the first strand 35a and the second strand 36a are not limited to metal strands, and may be made of resin strands or carbon wire, etc. Aramid is preferred for the resin strands. The resin strands are preferably made of nylon or polyester material, which has a higher heat resistance temperature than the resin forming the resin layer.

[0032] The first helical layer 35 is formed by spirally winding the first strand 35a along a first direction around the axis A (central axis) of the tube 31.

[0033] More specifically, the first helical layer 35 is formed by spirally winding a first group of wires 35ag, which consists of a plurality (for example, three) of first wires 35a. In this case, as shown in Figure 2, the first group of wires 35ag is wound such that the spiral pitch of the first helical layer 35 is constant (first pitch P1).

[0034] In this embodiment, the first pitch P1 is set to be different from the spacing between each first strand 35a constituting the first strand group 35ag. More specifically, the first pitch P1 is set to be greater than the spacing between each first strand 35a constituting the first strand group 35ag. When the first helical layer 35 is formed by a single first strand 35a, the pitch of the spiral of the first strand 35a becomes the first pitch P1.

[0035] Furthermore, the first helical layer 35 is not limited to being formed by three first strands 35a. The first helical layer 35 can be formed using one or any number of first strands 35a.

[0036] The second helical layer 36 is formed by overlapping the outer circumference of the first helical layer 35. The second helical layer 36 is formed by spirally winding the second strand 36a along a second direction around the axis A of the tube 31. In this case, the second direction is the direction that intersects the first direction.

[0037] More specifically, the second helical layer 36 is formed by winding a second group of wires 36ag, which consists of a plurality (for example, three) of second wires 36a, in a spiral shape. In this case, as shown in Figure 2, the second group of wires 36ag is wound such that the spiral pitch of the second helical layer 36 is constant (second pitch P2).

[0038] In this embodiment, the second pitch P2 is set to be different from the spacing between each second strand 36a constituting the second strand group 36ag. More specifically, the second pitch P2 is set to be greater than the spacing between each second strand 36a constituting the second strand group 36ag. Furthermore, the second pitch P2 is set to be equal to the first pitch P1. Note that if the second helical layer 36 is formed by a single first strand 36a, the pitch of the helix of the second strand 36a becomes the second pitch P2.

[0039] In this case, it is preferable that the helix formed in the second helical layer 36 is arranged such that the sign of its phase is different from that of the helix formed in the first helical layer 35.

[0040] The first resin layer 32 is made of, for example, a flexible resin material. The resin material is preferably a thermoplastic resin, and is preferably a urethane resin, polypropylene synthetic resin, polyethylene resin, polyamide resin, ethyl vinyl alcohol resin, or styrene block copolymer. The inner diameter of the first resin layer 32 is set to be equal to the inner diameter of the first helical layer 35. As a result, the first resin layer 32, together with the first helical layer 35, forms the inner circumferential surface of the medical tube 30.

[0041] Further, the outer diameter of the first resin layer 32 is set to be larger than the outer diameter of the first spiral layer 35 and smaller than the outer diameter of the second spiral layer 36. Accordingly, the first resin layer 32 is filled between the respective first element wires 35a and between the pitches of the first element wire group 35ag. Furthermore, the first resin layer 32 is filled between the respective second element wires 36a and between the pitches of the second element wire group 36ag at a position closer to the inner circumference of the second spiral layer 36. That is, the first resin layer 32 is filled over the entire area of the first spiral layer 35 and at a position closer to the inner circumference of the second spiral layer 36. Accordingly, the first resin layer 32 maintains the contact state of each contact portion between each first element wire 35a and each second element wire 36a.

[0042] Next, a method for manufacturing the medical tube 30 will be described according to the flowchart in FIG. 5.

[0043] In the manufacturing of this medical tube 30, a step of forming the first spiral layer 35 is performed in step S10. That is, as shown in FIGS. 6 and 7, the first element wire group 35ag is spirally wound around a molding core material 40. More specifically, the first element wire group 35ag is spirally wound around the core material 40 in a first direction around the axis A (for example, a clockwise direction).

[0044] In the subsequent step S20, a step of applying a first resin material 32a, which is the material of the first resin layer 32, to the first spiral layer 35 is performed. That is, for example, as shown in FIG. 8, the molten first resin material 32a is applied to the outer circumference of the first spiral layer 35.

[0045] As the first resin material 32a, a material having predetermined elasticity even after curing is selected. In FIGS. 8 to 10, the molten first resin material 32a is indicated with dots.

[0046] In this case, the first spiral layer 35 is coated with an amount of the first resin material 32a that is larger than the total volume of the gaps formed in the first spiral layer 35. That is, the first spiral layer 35 is coated with an amount of the first resin material 32a that is larger than the total volume of the gaps formed between the first element wires 35a and the gaps formed between the pitches of the first element wire group 35ag.

[0047] In this application step, it is possible to change the elastic properties and the like of the first resin material 32a along the axis A direction. Alternatively, in the application step, it is possible to change the thickness of the first resin material 32a applied to the first spiral layer 35 along the axis A direction. By applying the first resin material 32a in this manner, it becomes possible to vary the properties of the first resin layer 32 along the axis A.

[0048] In the subsequent step S30, a permeation step of the first resin material 32a applied to the first spiral layer 35 is performed. In this permeation step, for example, the core member 40 after the first resin material 32a has been applied is carried into a pressure chamber. Then, by increasing the internal pressure of the pressure chamber, a predetermined pressure is applied to the first resin material 32a. Thereby, the first resin material 32a permeates between the respective first strands 35a and between the pitches of the first strand group 35ag. Further, the first resin material 32a reaches the outer peripheral surface of the core member 40. Thereby, the first resin material 32a, together with the first spiral layer 35, forms a continuous inner peripheral surface. In this case, since the amount of the first resin material 32a is larger than the total volume of the gaps of the first spiral layer 35, the first spiral layer 35 is embedded inside the first resin layer 32.

[0049] In the subsequent step S40, a step of forming the second spiral layer 36 is performed. That is, as shown in FIGS. 9 and 10, the second strand group 36ag is spirally wound around the outer periphery of the first spiral layer 35 coated with the first resin material 32a. More specifically, the second strand group 36ag is spirally wound around the first spiral layer 35 in a second direction intersecting the first direction around the axis A (for example, a counterclockwise direction). In this case, a portion of the second spiral layer 36 closer to the inner periphery is embedded inside the first resin material 32a. Thereby, each second strand 36a comes into contact at a portion intersecting with each first strand 35a.

[0050] In the subsequent step S50, a curing step of the first resin material 32a is performed. This curing step is realized, for example, by cooling the molten first resin material 32a. Thereby, as shown in FIG. 10, a medical tube 30 including a tubular body 31 and the first resin layer 32 is formed.

[0051] In the following step S60, the medical tube 30 is removed from the core material 40.

[0052] In this embodiment, the medical tube 30 has a tubular body 31 that includes a first helical layer 35 formed by spirally winding a first strand 35a along a first direction around axis A, and a second helical layer 36 arranged on the outer circumference of the first helical layer 35 and formed by spirally winding a second strand 36a along a second direction intersecting the first direction around axis A. The medical tube 30 also has a gap defined by a first pitch P1 of the first strand group 35ag in the first helical layer 35, and a first resin layer 32 provided between the first helical layer 35 and the second helical layer 36. As a result, the medical tube 30 can be made highly productive and maintain appropriate flexibility.

[0053] In other words, the tubular body 31 of the medical tube 30 is composed of a two-layer structure: a first helical layer 35 formed by spirally winding a first strand 35a along a first direction, and a second helical layer 36 formed by spirally winding a second strand 36a along a second direction on the outer circumference of the first helical layer 35. Therefore, the tubular body 31 can be formed with excellent productivity without having to weave the first strand 35a and the second strand 36a6 together.

[0054] Furthermore, the medical tube 30 has a first resin layer 32 provided in the gap of the first helical layer 35 and between the first helical layer 35 and the second helical layer 36. By providing the first resin layer 32 in the gap of the first helical layer 35, the first resin layer 32 suppresses a large variation in the first pitch P1 in the axial A direction of the first helical layer 35 and deformation of the first helical layer 35 in the outer diameter direction. Furthermore, by providing the first resin layer 32 between the first helical layer 35 and the second helical layer 36, the contact state of each intersection portion of the first wire 35a and the second wire 36a is maintained. As a result, the first resin layer 32 suppresses a large variation in the pitch P2 in the axial A direction of the second helical layer 36 and deformation of the second helical layer 36 in the outer diameter direction. Here, the formation of the first resin layer 32 is significantly more productive than diffusion bonding, etc.

[0055] These features make it possible to provide medical tubing that offers excellent productivity while maintaining appropriate flexibility.

[0056] In this case, the first resin layer 32, together with the first helical layer 35, forms a continuous inner surface of the medical tube 30. This makes it possible to suppress fluctuations in the first pitch P1 of the first helical layer 35 caused by contact with the internal components, even when the medical tube 30 is used in a state where internal components can directly contact the inner surface of the medical tube 30.

[0057] (First Modification) Next, a first modification of this embodiment will be described with reference to Figures 11 to 14. As shown in Figures 11 and 12, in this modification, the medical tube 30 has a second resin layer 37 on the outer layer of the second helical layer 36.

[0058] In this modified example, the second resin material 37a forming the second resin layer 37 is a different resin material from the first resin material 32a forming the first resin layer 32. Here, the second resin material 37a is selected to be a material that has a predetermined elasticity even when cured. Note that the second resin material 37a may be the same resin material as the first resin material 32a.

[0059] Such medical tubes 30 are manufactured, for example, according to the flowchart shown in Figure 13.

[0060] In the manufacture of this medical tube 30, the processes described above from step S10 to step S50 are carried out first.

[0061] In the subsequent step S60, the second resin material 37a is applied to the second helical layer 36. That is, as shown in Figure 14, the molten second resin material 37a is applied to the outer circumference of the second helical layer 36. In Figure 14, the molten second resin material 37a is indicated by dots.

[0062] In this case, the second helical layer 36 is coated with an amount of the second resin material 37a that is greater than the total volume of the gaps formed in the second helical layer 36. That is, the second helical layer 36 is coated with an amount of the second resin material 37a that is greater than the total volume of the gaps formed between the second strands 36a and the gaps formed between the pitches of the second strand group 36ag.

[0063] In the following step S70, a penetration process is performed for the second resin material 37a applied to the second helical layer 36. In this penetration process, for example, the core material 40 after the second resin material 37a has been applied is brought into a pressure chamber. Then, by increasing the internal pressure of the pressure chamber, a predetermined pressure is applied to the second resin material 37a. As a result, the second resin material 37a penetrates between each second strand 36a and between the pitches of the second strand group 36ag. Furthermore, the second resin material 37a reaches the outer surface of the first resin layer 32. In this case, since the amount of the second resin material 37a is greater than the total volume of the gaps in the second helical layer 36, the second helical layer 36 is embedded inside the second resin material 37a.

[0064] In the subsequent step S80, a curing process is performed on the second resin material 37a. This curing process is achieved, for example, by cooling the molten second resin material 37a. This forms a medical tube 30 comprising the tubular body 31, the first resin layer 32, and the second resin layer 37. The cured second resin layer 37 adheres closely to the first resin layer 32 and seals the second helical layer 36.

[0065] In the following step S90, the medical tube 30 is removed from the core material 40.

[0066] With this modified configuration, by providing the second resin layer 37, it is possible to more accurately suppress significant fluctuations in the pitch P2 of the second helical layer 36 in the axial A direction, and displacement of the second helical layer 36 in the outer diameter direction.

[0067] Furthermore, when the medical tube 30 is used in the flexible tube portion 8 of the endoscope 1, the second resin layer 37 can function as the outer sheath of the flexible tube portion 8.

[0068] (Second Modification) When the first strand 35a and the second strand 36a are the same strand, the rigidity of the first helical layer 35 and the second helical layer 36 is proportional to the cube of the radius. Therefore, basically, the rigidity of the second helical layer 36 is higher than that of the first helical layer 35. When a medical tube 30 is constructed using a first helical layer 35 and a second helical layer 36 with different winding directions, the flexibility characteristics of the medical tube 30 tend to depend on the winding direction of the second helical layer 36. This modification is intended to correct such flexibility characteristics.

[0069] As shown in Figure 15, in this modified example, the first pitch P1 is set to a different value from the second pitch P2. More specifically, the first pitch P1 is set to be smaller than the second pitch P2. This makes it possible to make the flexibility characteristics of the medical tube 30 uniform.

[0070] Furthermore, if the flexibility characteristics of the medical tube 30 are intentionally set to be non-uniform depending on the application, it is also possible to set the first pitch P1 to be larger than the second pitch P2.

[0071] (Third Modification) Also, for example, as shown in Figure 16, the flexibility characteristics of the medical tube 30 can be adjusted by making the cross-sectional area of ​​the first strand 35a different from the cross-sectional area of ​​the second strand 36a. More specifically, the cross-sectional area of ​​the first strand 35a is set to be larger than the cross-sectional area of ​​the second strand 36a. This makes it possible to make the flexibility characteristics of the medical tube 30 uniform.

[0072] Furthermore, if the flexibility characteristics of the medical tube 30 are intentionally set to be non-uniform depending on the application, it is also possible to set the cross-sectional area of ​​the first strand 35a to be smaller than the cross-sectional area of ​​the second strand 36a.

[0073] (Fourth Modification) This modification is intended to increase the holding force of the first wire 35a and the second wire 36a by the first resin layer 32.

[0074] For this reason, the first strand 35a and the second strand 36a are subjected to a surface roughening process. Such a process can be achieved, for example, by scratching the surface of the strand with a file or the like. Alternatively, a chemical reaction using chemicals may be utilized.

[0075] These surface processing steps can be performed, for example, in step S5 before the step of forming the first helical layer 35, and in step S35 before the step of forming the second helical layer 36, as shown in Figure 17.

[0076] It is also possible to make the surface roughness of the first wire 35a and the surface roughness of the second wire 36a different. Such differentiation of surface roughness can be achieved by performing only one of the steps in step S5 and step S35. Alternatively, differentiation of surface roughness can be achieved by using files or the like with different roughness in steps S5 and S35.

[0077] (Fifth Modification) In this modification, the first wire 35a has a core wire 35a1 and an outer sheath 35a2. The core wire 35a1 is made of, for example, a metal wire. The outer sheath 35a2 is a covering member that covers the outer circumference of the core wire 35a1. This outer sheath 35a2 is made of, for example, a molten resin material.

[0078] Each first strand 35a constituting the first strand group 35ag is wound spirally around the core material 40 and then heated. As a result, the outer sheath 35a2 of each first strand 35a melts. A portion of the melted outer sheath 35a2 joins with a portion of the adjacent outer sheath 35a2. In this way, each first strand 35a constituting the first strand group 35ag is joined to each other, forming the first helical layer 35.

[0079] Similarly, the second wire 36a has a core wire 36a1 and an outer sheath 36a2. The core wire 36a1 is made of, for example, a metal wire. The outer sheath 36a2 is a covering member that covers the outer circumference of the core wire 36a1. This outer sheath 36a2 is made of, for example, a molten resin material.

[0080] Each second strand 36a constituting the second strand group 36ag is heated after being wound around the outer circumference of the first helical layer 35. As a result, the outer sheath 35a2 of each first strand 35a melts. A portion of the melted outer sheath 36a2 joins with a portion of the adjacent outer sheath 36a2. In this way, each second strand 36a constituting the second strand group 36ag is joined to each other, forming the second helical layer 36.

[0081] In this modified example, the first resin layer 32 is formed, for example, by applying the first resin material 32a to the outer circumference of the second helical layer 36. The applied first resin material 32a is cured after undergoing a penetration process into each gap in the first helical layer 35 and each gap in the second helical layer 36. This forms the first resin layer 32 that integrally covers the first helical layer 35 and the second helical layer 36.

[0082] In this configuration, the flexibility characteristics of the medical tube 30 can be adjusted by adjusting the friction coefficient μ1 between the first resin layer 32 and each outer sheath 35a2, the friction coefficient μ2 between the first resin layer 32 and each outer sheath 36a2, and the friction coefficient μ3 between each outer sheath 35a2 and each outer sheath 36a2.

[0083] Furthermore, the same material as the outer layers 35a2 and 36a2 can be used as the first resin material 32a. This improves the adhesion between the first resin layer 32 and the first helical layer 35 and the second helical layer 36.

[0084] Alternatively, the first resin material 32a can be made of a material with a higher melting point than each outer sheath 35a2, 36a2. This allows the outer sheaths 35a2, 36a2 to be melted when the first resin material 32a is applied. Therefore, the outer sheaths 35a2, 36a2 can be melted without directly heating the first wire 35a and the second wire 36a. This allows the first wires 35a of the first wire group 35ag and the second wires 36a of the second wire group 36ag to be joined together in the process of forming the first resin layer 32.

[0085] Furthermore, as shown in Figure 20, for example, it is possible to make the diameter of the core wire 35a1 of the first strand 35a different from the diameter of the core wire 36a1 of the second strand 36a. In this case, the diameter of the first strand 35a and the diameter of the second strand 36a can be made the same by adjusting the thickness of each outer sheath 35a2 and each outer sheath 36a2, respectively. Therefore, the flexibility characteristics of the medical tube 30 can be adjusted without changing the pitch P1 of the first helical layer 35 and the pitch P2 of the second helical layer 36.

[0086] It should be noted that the present invention is not limited to the embodiments and variations described above, and various modifications and changes are possible, all of which fall within the technical scope of the present invention.

[0087] For example, the configurations of the above-described embodiments and their respective modifications may be combined as appropriate. Furthermore, the application of the medical tube 30 is not limited to single-use endoscopes, but can also be applied to reusable endoscopes. Moreover, the application of the medical tube 30 is not limited to endoscopes, but can also be applied as a stent or the like.

[0088] [Note 1] A method for manufacturing a medical tube, comprising: supplying molten resin to a core material for molding; winding a first wire along a first direction on the outer surface of the molten resin to form a first helical layer; and curing the molten resin to form a first cylindrical layer.

[0089] [Note 2] A method for manufacturing a medical tube according to Note 1, comprising the step of cooling the molten resin in the step of forming the first cylindrical layer.

[0090] [Note 3] The method for manufacturing a medical tube according to Note 1, wherein at least a portion of the step of forming the first cylindrical layer is performed simultaneously with the step of forming the first helical layer.

[0091] 1… Endoscope 2… Insertion section 3… Control section 4… Universal cable 5… Connector 6… Tip section 7… Bending section 8… Flexible tube section 10… Imaging unit 11… Signal cable 12… Traction wire 13… Light guide 14… Treatment instrument channel 15… Outer sheath 20… Anti-bend section 21… Gripping section 22… Control section body 23… Treatment instrument insertion section 23a… Treatment instrument insertion port 25… Bending lever 26… Operation button group 30… Medical tube 31… Tube body 32… First resin layer 32a… First resin material 35… First helical layer 35a… First strand 35a1… Core wire 35a2… Outer sheath 35ag… First strand group 36… Second helical layer 36a… Second strand 36a1… Core wire 36a2… Outer sheath 36ag… Second strand group 37… Second resin layer 37a… Second resin material 40… Core material A… Shaft

Claims

1. A medical tube comprising: a tubular body including: a first helical layer in which first strands are formed spirally along a first direction around an axis; a second helical layer arranged on the outer circumference of the first helical layer and in which second strands are formed spirally along a second direction intersecting the first direction around the axis; a gap defined by the pitch of the first strands in the first helical layer; and a first resin layer provided between the first helical layer and the second helical layer.

2. The medical tube according to claim 1, characterized in that the surface roughness of the first strand is different from the surface roughness of the second strand.

3. The medical tube according to claim 1, characterized in that the cross-sectional area of ​​the first strand is different from the cross-sectional area of ​​the second strand.

4. The medical tube according to claim 3, characterized in that the cross-sectional area of ​​the first strand is larger than the cross-sectional area of ​​the second strand.

5. The medical tube according to claim 1, characterized in that the pitch of the first strand in the first helical layer is different from the pitch of the second strand in the second helical layer.

6. The medical tube according to claim 5, characterized in that the pitch of the first strands in the first helical layer is smaller than the pitch of the second strands in the second helical layer.

7. The medical tube according to claim 1, further comprising a second resin layer disposed on the outer circumference of the second helical layer.

8. The medical tube according to claim 7, characterized in that the first resin layer is formed of a resin different from the second resin layer.

9. The medical tube according to claim 1, characterized in that the first resin layer has different properties along the axis.

10. The medical tube according to claim 1, characterized in that the first helical layer and the first resin layer form a continuous inner circumferential surface that can come into contact with an internal object.

11. The medical tube according to claim 1, characterized in that the tube body includes at least one of the following: a first helical layer in which a first group of wires arranged in the axial direction is formed in a spiral shape, and a second helical layer in which a second group of wires arranged in the axial direction is formed in a spiral shape.

12. The medical tube according to claim 1, wherein the tube body includes a first helical layer in which two or more of the first strands are arranged in the axial direction to form a first strand group in a spiral shape, and the spacing between two or more of the first strands in the first strand group is different from the pitch of the first strand group in the first helical layer.

13. The medical tube according to claim 12, characterized in that the first resin layer is provided between two or more of the first strands.

14. The medical tube according to claim 1, wherein the tube body includes a second helical layer in which two or more second strands are arranged in the axial direction and a second strand group is formed in a spiral shape, and the spacing between two or more second strands in the second strand group is different from the pitch of the second strand group in the second helical layer.

15. The medical tube according to claim 1, characterized in that at least one of the first strand and the second strand is made of metal.

16. The medical tube according to claim 1, characterized in that the spiral formed by the first strand and the spiral formed by the second strand have different phase signs.

17. An endoscope characterized in that the insertion portion includes a tubular body having a first helical layer in which first strands are formed spirally along a first direction around the axis, and a second helical layer arranged on the outer circumference of the first helical layer and in which second strands are formed spirally along a second direction intersecting the first direction around the axis, and a gap defined by the pitch of the first strands in the first helical layer, and a first resin layer provided between the first helical layer and the second helical layer.

18. The endoscope according to claim 17, further comprising an internal component disposed inside the insertion portion along the axial direction, wherein the medical tube and the internal component are configured to be in direct contact with each other.

19. A method for manufacturing a medical tube, comprising: the steps of: winding a first wire along a first direction around the axis of a core material for molding to form a first helical layer; forming a gap in the first helical layer defined by the pitch of the first wires, and forming a first resin layer on the outer circumference of the first helical layer; and winding a second wire around the outer circumference of the first resin layer along a second direction intersecting the first direction around the axis to form a second helical layer.

20. A method for manufacturing a medical tube according to claim 19, comprising the step of roughening the surface of at least one of the strands of the first material before forming the first helical layer and the second material before forming the second helical layer.

21. The method for manufacturing a medical tube according to claim 20, characterized in that the step of roughening the surface of the wire is achieved by scratching the surface of the wire.

22. The method for manufacturing a medical tube according to claim 19, characterized by comprising the step of forming a second resin layer on the outer circumference of the second helical layer.

23. A method for manufacturing a medical tube according to claim 19, characterized by comprising the step of removing the first helical layer from the core material.

24. The method for manufacturing a medical tube according to claim 19, characterized in that the step of arranging the first resin layer includes the steps of applying resin to the outer circumference of the first helical layer and allowing the resin to penetrate the gap.

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