JP4418460B2 - Endoscope - Google Patents

Description

  The present invention relates to an endoscope that performs sterilization after use by high-pressure steam sterilization.

  Conventionally, by inserting a long and thin insertion portion into a body cavity, the inside of a body cavity can be observed, and various medical treatments can be performed using a treatment instrument inserted into a treatment instrument channel as necessary. Endoscopes are widely used.

  In particular, endoscopes used in the medical field are used to observe various organs by inserting an insertion portion into a body cavity and using a treatment instrument inserted into a treatment instrument channel of an endoscope. Take action.

  For this reason, when an endoscope or treatment tool that has been used once is reused for another patient, it is necessary to prevent infection between patients via the endoscope or treatment tool. Must be cleaned and disinfected.

  In recent years, autoclave sterilization (high pressure steam sterilization), which can be used immediately after sterilization without complicated work and has a low running cost, is becoming the mainstream of disinfection sterilization treatment of medical devices.

  For example, Japanese Patent Application Laid-Open No. 10-276968 discloses an endoscope incorporating an annealed tube so that the built-in tube does not shrink even after sterilization by an autoclave and sufficient sterilization can be repeated. ing.

  However, in the endoscope disclosed in Japanese Patent Laid-Open No. 10-276968, the tube inserted through the insertion portion is pre-annealed, so that the amount of contraction of the tube is reduced by the contraction of the resin outer skin layer. Small relative to the amount of shrinkage. For this reason, the tube is loosened in the insertion portion, and there is a possibility that the light guide cable and other built-in objects may be pressed and problems such as breakage may occur.

Further, when the endoscope is repeatedly subjected to a heat load during the high-temperature and high-pressure steam sterilization, the resin member used for the outer skin layer of the insertion portion is softened. When this resin member is softened, when the spiral tube disposed inside the resin member is incorporated in a reduced diameter state, the outer diameter of the flexible tube is exerted by a force in the diameter increasing direction. May change in the direction of expansion. Further, when the resin member absorbs moisture and swells, it may be deformed in the direction in which the outer diameter of the insertion portion is enlarged.
JP-A-10-276968

  Since the endoscope is for inserting the insertion portion into the body cavity and observing the inside of the body cavity, or performing a treatment or the like, when the endoscope is deformed in the direction in which the diameter of the insertion portion increases, as described above, Compared to the initial state, the insertability is degraded.

  For this reason, there has been a demand for an endoscope that prevents the insertion portion from deteriorating by preventing a change in the outer diameter of the insertion portion from being expanded by a heat load caused by the high-temperature and high-pressure steam sterilization process.

The present invention has been made in view of the above circumstances, an endoscope which prevents preventing the insertion of deterioration changes the flexible tube outside diameter dimension of the insertion portion is expanded by the heat load due to high-temperature high-pressure steam sterilization step The purpose is to provide.

To achieve the above object, an endoscope according to an aspect of the present invention includes a spiral tube formed by spirally winding a metal strip, a mesh tube that covers the outer periphery of the spiral tube, and an outer surface of the mesh tube. In an endoscope that has an insertion portion provided with a flexible tube provided with a resin outer skin layer and is sterilized at high temperature and high pressure steam for a predetermined time at a predetermined temperature after use ,
At the time of forming the flexible tube, by forming the spiral tube in a state in which the diameter of the spiral tube is expanded in advance with respect to a natural state, when the outer skin layer is softened under the heat load during the high-temperature high-pressure steam sterilization , A force in the direction of reducing the diameter acts on the spiral tube.

The endoscope of the present invention has the advantage of preventing the to insertion of the deterioration preventing a change of the flexible tube outside diameter dimension of the insertion portion by the thermal load due to high-temperature high-pressure steam sterilization step is expanded.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 relate to a first embodiment of the present invention, FIG. 1 is a diagram illustrating a schematic configuration of an endoscope apparatus, FIG. 2 is a diagram illustrating a configuration of a flexible tube, and FIG. It is a figure explaining the built-in thing which penetrates.

  As shown in FIG. 1, an endoscope apparatus 1 according to this embodiment includes an electronic endoscope (hereinafter referred to as an endoscope) 2 provided with, for example, a CCD as an imaging unit, and a light source apparatus 3 that supplies illumination light. The video processor 4 mainly controls the image pickup means and processes a signal obtained from the image pickup means, and a monitor 5 connected to the video processor 4.

  The endoscope 2 includes an elongated and flexible insertion portion 10, an operation portion 11 provided continuously with a proximal end portion of the insertion portion 10, and a flexibility extending from a side of the operation portion 11. And a universal cord 12 having

  A connector 12 a detachably attached to the light source device 3 is provided at the end of the universal cord 12. By connecting the connector 12a to the light source device 3, illumination light from a lamp (not shown) provided in the light source device 3 is transmitted through a light guide (not shown) of the endoscope 2 to irradiate an observation site. ing.

  The connecting portion between the insertion portion 10 and the operation portion is provided with an insertion portion bending prevention member 7a made of an elastic member that prevents sudden bending, and the connection portion between the operation portion 11 and the universal cord 12 is the same. Further, an operation portion folding preventing member 7b is provided, and a connector portion folding preventing member 7c is similarly provided at a connecting portion between the universal cord 12 and the connector 12a.

  The elongated and flexible insertion portion 10 of the endoscope 2 is rigid in order from the distal end side, for example, a distal end rigid portion 13 provided with an observation window and an illumination window (not shown) on the distal end surface, and a plurality of bending pieces. A bending portion 14 that can be connected and bent, and a flexible tube 15 that is a flexible soft portion having delicate flexibility and elasticity are connected to each other. The bending portion 14 is bent by appropriately operating a bending operation knob 16 provided in the operation portion 11 so that the distal end surface of the distal end rigid portion 13 provided with an observation window or the like is directed in a desired direction. It has become.

  In addition to the bending operation knob 16, the operation unit 11 performs an air supply operation and a water supply operation when a cleaning liquid or gas is ejected from an air supply / water supply nozzle (not shown) provided on the distal end surface toward the observation window. A pneumatic operation button 17 and a suction operation button 18 for performing a suction operation through a suction port (not shown) provided on the distal end surface, a plurality of remote switches 19 for remotely operating the video processor 4 and an insertion portion of the endoscope 2 A treatment instrument insertion port 20 that communicates with a treatment instrument channel disposed on the instrument is provided.

  An electrical connector portion 12b is provided on the side of the connector 12a. A signal connector 4b of a signal cable 4a connected to the video processor 4 is detachably connected to the electrical connector portion 12b. By connecting the signal connector 4b to the electrical connector portion 12b, the imaging means of the endoscope 2 is controlled, and a video signal is generated from the electrical signal transmitted from the imaging means, and the endoscopic observation image is displayed. It is displayed on the screen of the monitor 5. The electrical connector portion 12b is provided with a vent (not shown) that communicates the inside and the outside of the endoscope 2. For this reason, a waterproof cap (hereinafter abbreviated as a waterproof cap) 9a, which will be described later, provided with a pressure adjustment valve (not shown) that closes the vent is detachably attached to the electrical connector portion 12b of the endoscope 2. It is the composition.

  The connector 12a has a gas supply base 12c that is detachably connected to a gas supply source (not shown) built in the light source device 3, and a water supply tank that is detachably connected to a water supply tank 8 that is a liquid supply source. A pressure base 12d and a liquid supply base 12e, a suction base 12f connected to a suction source (not shown) for performing suction from the suction port, and an injection base 12g connected to a water supply means (not shown) for water supply are provided. ing.

  Further, when a high frequency leakage current is generated in the endoscope 2 when performing a high frequency treatment or the like, an earth terminal base 12h is provided for returning the leakage current to a high frequency treatment device (not shown).

  The endoscope 2 is configured to be capable of high-pressure steam sterilization after washing when used for observation or treatment. When the endoscope 2 is high-pressure steam sterilized, the waterproof cap 9a is used. Is attached to the electrical connector portion 12b.

  When the endoscope 2 is sterilized by high-pressure steam, the endoscope 2 is stored in the sterilization storage case 50. The sterilization storage case 50 includes a tray 51, which is a case body, and a lid member 52. The tray 51 includes parts such as an insertion portion 10, an operation portion 11, a universal cord 12, and a connector 12a of the endoscope 2. A restricting member (not shown) corresponding to the shape of the endoscope is disposed so as to fit in a predetermined position. The tray 51 and the lid member 52 are formed with a plurality of vent holes for guiding high-pressure steam.

  As shown in FIG. 2, the flexible tube 15 includes a spiral tube 15a in which a thin strip-shaped metal piece is spirally wound from the innermost layer side, a mesh tube 15b in which a metal strand or a non-metal strand is knitted, and a resin It is configured by laminating an outer skin layer 15c formed of a material. The outer skin layer 15c is made of, for example, an ester-based thermoplastic elastomer, and various built-in objects shown in FIG.

  The outer skin layer 15c is not limited to an ester thermoplastic elastomer, but may be composed of an amide thermoplastic elastomer, a styrene resin, a fluorine rubber, a silicon rubber, or a blended material thereof.

  The resin member used for the outer skin layer 15c is selected in consideration of durability at the time of use, insertion property, etc., chemical resistance against chemicals used at the time of cleaning and disinfection, and the like. For this reason, some resin members are molded in a state where the thermal deformation temperature is lower than the temperature conditions of the high-temperature and high-pressure steam sterilization process, or in a state of being pulled by conditions such as extrusion molding at the time of molding, and deformation occurs due to the stress release. There is something.

  As shown in FIG. 3, the built-in object is made of metal and is made of a metal bending wire 21 that bends the bending portion 14 by advancing and retreating by remote operation of the bending operation knob 16, and the bending wire 21 is loosely fitted. A metal wire covering coil 22 to be covered, a light guide 24 for supplying illumination light, an air / water feeding tube 25 and a treatment instrument insertion channel tube 26 which are resin tube bodies, a plurality of signal cables 27 and the like.

  The air supply / water supply tube 25 and the treatment instrument insertion channel tube 26 are respectively locked and fixed to connection portions (not shown) of the operation portion 11 and the distal end rigid portion 13 connected to both ends of the insertion portion 10. The treatment instrument insertion channel tube 26 and the air / water supply tube 25 are formed of a material having high chemical resistance such as PTFE.

  When the endoscope 2 is repeatedly sterilized in the high-temperature and high-pressure steam sterilization process, the flexible tube 15, the treatment instrument insertion channel tube 26, and the air / water supply tube 25 are initialized by the heat load of the high-temperature and high-pressure steam sterilization process. Compared to the state, shrinkage in the longitudinal direction occurs. Note that the amount of shrinkage at this time corresponds to, for example, the amount of tension generated during the molding described above.

  In this embodiment, the contraction amount is X1 for the treatment instrument insertion channel tube 26, X2 for the air / water supply tube 25, and Y for the flexible tube 15, and the following relationship is set between these contraction amounts.

Y≤X1, X2
This is because, for example, before the treatment instrument insertion channel tube 26 and the air / water supply tube 25 are incorporated into the flexible tube 15, a heat load is applied to the flexible tube 15 to release the stress in advance, and the heat deformation temperature is increased. The flexible tube 15 is formed of a material that is high and hardly affected by the heat load.

  In the present embodiment, the insertion portion 10 is described. However, the universal cord 12 and a flexible tube (not shown) that passes through the universal cord 12 and an air / water feed tube 25 that is a built-in object have the same configuration. I have to.

Here, typical conditions for autoclaving the endoscope 2 will be described.
As typical conditions, the American Standards Association approved and the American Standard ANSI / AAMI ST37-1992 issued by the Medical Device Development Association, the pre-vacuum type sterilization process at 132 ° C for 4 minutes and the gravity type sterilization process at 132 ° C. 10 minutes.

  The temperature condition during the sterilization process of high-pressure steam sterilization varies depending on the type of the high-pressure steam sterilization apparatus and the time of the sterilization process, but is generally set in the range of about 115 ° C to 138 ° C. Some sterilizers can be set to around 142 ° C.

  About time conditions, it changes with temperature conditions of a sterilization process. Generally, it is set to about 3 to 60 minutes. Some types of sterilizers can be set to about 100 minutes.

  The pressure in the sterilizer in this step is generally set to about +0.2 MPa with respect to atmospheric pressure.

Next, a high temperature and high pressure steam sterilization process of an endoscope in a general pre-vacuum type will be briefly described.
First, a waterproof cap 9a is attached to the electrical connector portion 12b of the endoscope 2 that is a device to be sterilized, accommodated in a sterilization storage case 50, and placed in a sterilization apparatus. By attaching the waterproof cap 9a to the electrical connector portion 12b, the pressure regulating valve is closed to close the vent. That is, the inside and the outside of the endoscope 2 are hermetically sealed. Then, the inside of the sterilization apparatus before the high-temperature and high-pressure steam sterilization process is brought into a reduced pressure state (pre-vacuum process).

  This pre-vacuum process is a process for infiltrating the steam into the details of the sterilization target device during the sterilization process. By reducing the pressure inside the sterilization apparatus, high-pressure and high-temperature steam is distributed throughout the sterilization target device. Become. The pressure in the sterilizer in this pre-vacuum process is generally set to about -0.07 to -0.09 MPa with respect to atmospheric pressure.

  However, when the pressure in the sterilizer decreases in the pre-vacuum process, the external pressure becomes lower than the internal pressure of the endoscope 2 and a pressure difference is generated. Then, the pressure adjustment valve of the waterproof cap 9a is opened, and the inside and the outside of the endoscope 2 are in communication with each other through the vent. This prevents a large pressure difference from occurring. That is, the endoscope 2 is prevented from being damaged by the pressure difference between the internal pressure and the external pressure.

Next, sterilization is performed by sending high-pressure high-temperature steam into the sterilizer (sterilization process).
In this sterilization step, the inside of the sterilizer is pressurized. Then, a pressure difference is generated such that the external pressure is higher than the internal pressure of the endoscope 2. For this reason, the pressure regulating valve of the waterproof cap 9a is closed to block high-pressure steam from passing through the vent and entering the endoscope.

  However, the high-pressure steam is formed of fluorine rubber, silicon rubber, or the like which is a sealing means provided in the outer skin layer 15c of the flexible tube 15 formed of a polymer material or a connecting portion of the exterior body of the endoscope 2. The light penetrates through the O-ring and the like and gradually enters the endoscope.

  At this time, the exterior body of the endoscope 2 is in a state in which pressure from the outside to the inside is generated by adding the pressure decompressed in the pre-vacuum process and the pressure pressurized in the sterilization process.

  Next, in order to dry the sterilization target device after sterilization, the inside of the sterilization apparatus is again depressurized and dried (drying step) after the sterilization step. In this drying step, the inside of the sterilizer is decompressed to remove steam from the inside of the sterilizer, thereby promoting the drying of the sterilization target device in the sterilizer. The pressure in the sterilizer in this drying step is generally set to about -0.07 MPa to -0.09 MPa with respect to atmospheric pressure. In addition, the said drying process is arbitrarily performed as needed.

  In the decompression process after the sterilization process, a pressure difference is generated such that the pressure in the sterilization apparatus decreases and the external pressure becomes lower than the internal pressure of the endoscope 2. When this pressure difference occurs, the pressure regulating valve of the waterproof cap 9a is opened almost simultaneously, and the inside and outside of the endoscope 2 are in communication with each other through the vent, so that a large gap is formed between the inside and outside of the endoscope. A pressure difference is prevented from occurring. When the internal pressure and the external pressure of the endoscope 2 become substantially equal, the pressure adjusting valve of the waterproof cap 9a is closed. And the pressure reduction process is complete | finished and the inside of an apparatus becomes atmospheric pressure.

  At the end of the entire high-pressure steam sterilization process, the exterior body of the endoscope 2 is in a state in which pressure from the outside toward the inside is generated by the amount reduced in the pressure reducing process. Then, by removing the waterproof cap 9a from the electrical connector portion 12b, the inside and the outside of the endoscope 2 are communicated with each other by the vent, and the inside of the endoscope 2 becomes atmospheric pressure, and the exterior of the endoscope 2 The load due to the pressure difference that occurred in the body is eliminated.

  As described above, when the endoscope 2 is repeatedly sterilized in the high-temperature and high-pressure steam sterilization process, the flexible tube 15, the treatment instrument insertion channel tube 26, and the air / water supply tube 25 are respectively Y, X1, and X2 due to heat load. Shrink.

  At this time, since the relationship of Y ≦ X1, X2 is set among the shrinkage amounts Y, X1, X2 of the flexible tube 15, the treatment instrument insertion channel tube 26, and the air / water supply tube 25, the flexible tube When 15 is contracted, the treatment instrument insertion channel tube 26 and the air / water supply tube 25 are contracted to the same level or more. For this reason, the treatment instrument insertion channel tube 26 and the air / water supply tube 25 do not slack and meander in the flexible tube 15.

  That is, the bending wire 21, the wire covering coil 22, the light guide 24, the signal cable 27, and the like, which are other built-in objects, are not compressed by the treatment instrument insertion channel tube 26 and the air / water supply tube 25.

  Moreover, the treatment instrument insertion channel tube 26 is normally inserted and removed frequently with treatment instruments (not shown) and cleaning instruments. For this reason, if the treatment instrument insertion channel tube 26 is slack and meandering, a force more than necessary is required when inserting or removing the treatment instrument or the cleaning instrument. Although the inside of the tube 26 is damaged, buckled, or pierced in the worst case, in the present embodiment, there is no meandering of the treatment instrument insertion channel tube 26, so that the treatment instrument and the cleaning instrument are inserted. Will not be hindered.

  As described above, the amount of contraction of the treatment instrument insertion channel tube and the air / water supply tube inserted and arranged in the flexible tube is set to be equal to or larger than the amount of contraction of the flexible tube. Even when a heat load is applied by the high-temperature and high-pressure steam sterilization process, it is possible to prevent the treatment instrument insertion channel tube and the air / water supply tube from loosening and meandering in the flexible tube. This prevents other built-in components from being pressed and damaged by the treatment instrument insertion channel tube and the air / water supply tube.

  In addition, since the treatment instrument insertion channel tube does not sag and meander, it is possible to ensure good insertion properties of treatment instruments and cleaning instruments.

  As a result, it is possible to prevent defects in the internal components after high-temperature and high-pressure steam sterilization, and the work for inserting the treatment tool and the work for cleaning the inside of the channel tube can be performed smoothly before and after the high-temperature and high-pressure steam sterilization. It can be done.

  In addition, when the treatment instrument insertion channel tube 26 and the air / water supply tube 25 are locked and fixed to the connection portions inside both ends of the insertion portion 10 (not shown), the other built-in objects are not slackened in advance. You may make it hold and fix. The amount of looseness at that time is set to be equivalent to the amount of shrinkage caused by the heat load of the high-temperature and high-pressure steam sterilization process for the treatment instrument insertion channel tube 26 and the air / water supply tube 25 alone.

  As a result, when the treatment instrument insertion channel tube 26 and the air / water supply tube 25 are shrunk due to repeated heat loads caused by the high-temperature and high-pressure steam sterilization process, the treatment instrument insertion channel tube 26 and the air / water supply tube 25 are compressed. The tensile load on itself is reduced. In addition, the tensile load applied to the connection portion fixing the treatment instrument insertion channel tube 26 and the air / water supply tube 25 is also reduced, and the durability of the treatment instrument insertion channel tube 26 and the air / water supply tube 25 is improved. Can be made.

  By the way, when the endoscope is repeatedly subjected to a heat load during high-temperature high-pressure steam sterilization, the resin member used for the outer skin layer of the insertion portion is softened. Then, when the spiral tube disposed inside the resin member is incorporated in a reduced diameter state, the force in the diameter expansion direction acts to change the direction of the outer diameter of the flexible tube to increase. There are things to do. Further, when the resin member absorbs moisture and swells, it may be deformed in the direction in which the outer diameter of the insertion portion is enlarged.

  Thus, when it deform | transforms in the direction where the diameter dimension of an insertion part becomes large, compared with an initial state, insertability will deteriorate. For this reason, there has been a demand for an endoscope that prevents the insertion portion from deteriorating by preventing a change in the outer diameter of the insertion portion from being expanded by a heat load caused by the high-temperature and high-pressure steam sterilization process.

  As shown in FIG. 4 illustrating the state of the spiral tube, the spiral tube 15a constituting the flexible tube 15 of the present embodiment returns to the natural state when the diameter is changed from φD, which is the natural state, to the expanded state. A force for brazing (in the direction of diameter reduction) is applied, and a force for returning to the natural state (in the direction of diameter expansion) is applied when the diameter is changed from φD, which is a natural state, to a reduced diameter state.

  Accordingly, when the helical tube 15a is incorporated with a reduced diameter when forming the flexible tube 15, the thermal deformation temperature of the outer skin layer (not shown) subjected to the heat load by the high-temperature high-pressure steam sterilization process is low. The outer skin layer softens and changes in the direction in which the diameter of the spiral tube 15a increases. That is, by receiving a heat load due to the high-temperature and high-pressure steam sterilization process, the diameter of the flexible tube 15 before the heat load is applied becomes larger. For this reason, in this embodiment, when the flexible tube 15 is formed, the diameter of the spiral tube 15a is set to a slightly small diameter expanded state in advance, that is, to return to the natural state (the direction of diameter reduction). It is assembled and molded in a state where force is applied.

  As a result, when the insertion portion 10 receives a heat load in the high-temperature and high-pressure steam sterilization process, even when the outer skin layer is softened, a force in a direction to reduce the diameter is always applied to the spiral tube 15a. An increase in the outer diameter of the flexible tube 15 is reliably prevented.

  In this figure, the spiral tube 15a is single, but the spiral tube may be composed of double or triple.

  For the outer skin layer, a material having low water absorption, that is, a material that hardly swells or a material that shrinks and deforms by the addition of heat is selected. However, even when the thickness of the outer skin layer tends to increase due to the swelling of the outer skin layer, the outer diameter dimension of the flexible tube 15 can be obtained by incorporating the spiral tube 15a that has been previously expanded in diameter as described above. It becomes the composition which does not increase.

  In this way, when forming the flexible tube, the outer diameter of the insertion portion can be obtained even when subjected to a thermal load due to repeated high-temperature and high-pressure steam sterilization processes by incorporating the diameter of the spiral tube with the diameter expanded from the natural state in advance. It is possible to always ensure a good insertion property without increasing the size.

When the spiral tube 15a is covered with the mesh tube 15b, the mesh tube 15b is in close contact with the spiral tube 15a in the natural state (φD) as shown in FIG. 5 for explaining the relationship between the spiral tube and the mesh tube. By covering in such a state that the outer skin layer is softened under the heat load of the high-temperature and high-pressure steam sterilization process, and the force in the direction of expanding the diameter can be applied to the helical tube 15a, the tightly meshed tube the outer diameter dimension of the flexible tube 15 is prevented from being increased by 15b.

  By the way, when the endoscope is sterilized by the high-temperature high-pressure steam sterilizer, the endoscope is stored in the sterilization storage case 50. The sterilization storage case 50 is provided with a regulating member that houses the endoscope in a prescribed shape, and the insertion portion has a curved shape (curved shape) by the regulating member. For this reason, by repeatedly performing the high-temperature and high-pressure steam sterilization process, there is a risk that the outer resin used in the bending portion and the resin tubes inserted in the insertion portion are thermally deformed and the bending portion is bent and wrinkled. was there. If the bending portion is bent and wrinkled, problems such as deterioration of insertability and an increase in the amount of bending operation force occur. For this reason, there has been a demand for an endoscope that can reduce bending at the normal temperature after the high-temperature and high-pressure steam sterilization process, and can ensure good insertability and operability even after the high-temperature and high-pressure steam sterilization process.

  As shown in the drawing for explaining the configuration of the bending portion in FIG. 6, the proximal end side of the bending portion 14 constituting the insertion portion 10 of the present embodiment, which is bent by remote operation of the bending operation knob 16, is a flexible tube. 15 is connected and fixed by a screw or the like to a tip cap 31 formed of stainless steel or aluminum.

  The flexible tube 15 includes a spiral tube 15a in which a metal strip such as a stainless steel strip is spirally wound, and a mesh tube in which a metal member such as a stainless steel wire that is in close contact with the spiral tube 15a is knitted in a net shape. 15b and an outer skin layer 15c made of a resin material covering the outside of the mesh tube 15b are laminated. The outer skin layer 15c is not limited to an ester-based thermoplastic elastomer, but is formed of an amide-based thermoplastic elastomer, a styrene resin, a fluorine-based rubber, a silicon rubber, or a blended material thereof.

  The bending portion 14 is formed by braiding a joint piece 33 formed of a plurality of tubular metal members such as stainless steel rotatably connected by rivets 32 and the like, and a thin metal wire disposed outside the joint piece 33. The mesh tube 34 is composed of a resin-made outer skin layer 35 having flexibility such as fluoro rubber covering the mesh tube 34.

  The joint piece 33a constituting the proximal end side of the bending portion 14 is fitted and fixed to the distal end cap 31 with a screw or the like. On the other hand, the joint piece 33b constituting the distal end side of the bending portion 14 is connected and fixed to a distal end body 36 made of metal such as stainless steel with a screw or the like.

  The distal end body 36 is provided with a treatment instrument insertion channel 37 and the like. Although not shown, an air / water feeding tube is inserted into the bending portion 14, and an opening thereof is provided in the tip end body 36.

  The outside of the tip body 36 is made of a resin having good chemical resistance such as polyphenylsulfone, polysulfone, polyethersulfone, polyetheretherketone, and heat resistance higher than the temperature of the high-temperature high-pressure steam sterilization process. The formed insulating cover member 38 is provided.

  The distal end side of the outer skin layer 35 covers the proximal end side of the distal end portion main body 36, the end portion contacts the insulating cover member 38, and the proximal end side covers the distal end side of the flexible tube 15. The portion is in contact with the outer skin layer 15c. Then, both end portions of the outer skin layer 35 are fastened together by a fixing thread 41 wound around the outer peripheral surface, and are fixed in a state where they are pressed against the inner tip portion main body 36 and the tip cap 31 respectively.

  An adhesive 42 made of an epoxy resin or the like is applied to the outer surface side of the fixing thread 41 over the outer skin layer 35, the fixing thread 41, and the insulating cover member 38. Accordingly, the fixing thread 41 is covered and the boundary portion between the insulating cover member 38 and the outer skin layer 35 is sealed in a watertight manner.

  The outer skin layer 35 and the treatment instrument insertion channel tube 26 described above may be configured by combining different thicknesses and materials depending on the functions of various types of the endoscope 2.

  For this reason, the hardness as the bending rigidity in the axial direction as the bending portion 14 also varies depending on the thickness and material of the outer skin layer 35, the treatment instrument insertion channel tube 26, and the like. Therefore, depending on the model of the endoscope 2, the outer skin layer 35 has a greater effect on the bending rigidity as the bending portion 14 when the hardness against the bending rigidity is greater, or the treatment instrument insertion channel tube 26 is bent. There are cases where the effect on rigidity is large. In addition, if the hardness as this bending rigidity becomes hard, the amount of bending operation force will become heavy.

  When the endoscope 2 configured as described above is sterilized with a high-temperature high-pressure steam sterilizer, the insertion portion 10 is stored in the sterilization storage case 50. As a result, the flexible tube 15 and the bending portion 14 are subjected to the heat load of the high-temperature and high-pressure steam sterilization process in a bent state.

  The material used for the outer skin layer 35 and the treatment instrument insertion channel tube 26 has a thermal deformation temperature lower than the temperature condition of the heat load in the high-temperature and high-pressure steam sterilization process, so that it is bent at room temperature after the sterilization process. There is something that happens.

  Even if the material has a high thermal deformation temperature (even if it is not subjected to a thermal load), if it is left in a bent state for a long period of time, bending deformation will occur due to plastic deformation over time. May end up.

  Usually, the tube body comprised with the resin material produces a difference in the bending deformation at the time of repeatedly receiving the heat load by a high temperature / high pressure steam sterilization process by the difference of the following conditions.

(1) Difference in heat deformation temperature of materials
(2) Difference in thickness of tube body (3) Difference in outer diameter of tube body.

Also, (4) the difference in strength of plastic deformation of the original material can be mentioned.

In the present embodiment, for example, when the outer skin layer 35 has a greater influence on the hardness of the bending rigidity as the bending portion 14 than the treatment instrument insertion channel tube 26,
As a material of the outer skin layer 35,
(1) One having a higher heat deformation temperature than the material used for the treatment instrument insertion channel tube 26 (2) One having a smaller thickness than the treatment instrument insertion channel tube 26 (4) Than the treatment instrument insertion channel tube 26 A material having a strong resistance to plastic deformation is selected. That is, the treatment instrument insertion channel tube 26 disposed inside the outer skin layer 35 is subjected to the conditions (1), (2), and (4). By forming in combination, the outer skin layer 35 is configured to be less likely to bend and deform than the treatment instrument insertion channel tube 26.

Conversely, when the treatment instrument insertion channel tube 26 has a greater influence on the hardness of the bending rigidity as the bending portion 14 than the outer skin layer 35,
(1) Those having a higher thermal deformation temperature than the material used for the outer skin layer 35 (2) Those having a lower wall pressure than the outer skin layer 35 (3) Those having a smaller outer diameter than the outer skin layer 35 (4) A material having a stronger resistance to plastic deformation than the outer skin layer 35 is selected.

  By forming the treatment instrument insertion channel tube 26 by combining these conditions (1), (2), (3), and (4), the treatment instrument insertion channel tube 26 is bent and deformed more than the outer skin layer 35. Difficult composition.

  Therefore, for example, when the outer skin layer 35 has a greater influence on the hardness of the bending rigidity as the bending portion 14 than the treatment instrument insertion channel tube 26, the shape of the bending portion 14 is maintained by the outer skin layer 35. The The outer skin layer 35 is more difficult to bend and deform than the treatment instrument insertion channel tube 26 when it is repeatedly subjected to a heat load by the high-temperature high-pressure steam sterilization process.

  Thus, even if the treatment instrument insertion channel tube 26 is bent and deformed, the bending deformation that has occurred in the treatment instrument insertion channel tube 26 is corrected by the outer skin layer 35 that is difficult to bend and deform. Therefore, the shape of the bending portion 14 is maintained in a state where there is no bending deformation or a small amount of bending deformation, and the influence on the operation force during bending operation is small.

The same applies to the case where the treatment instrument insertion channel tube 26 has a greater influence on the hardness of the bending rigidity as the bending portion 14 than the outer skin layer 35.

  In this way, by bending the member that affects the hardness as the bending rigidity in the axial direction as the bending portion, the bending after being subjected to the heat load in the repeated high-temperature and high-pressure steam sterilization process by making it difficult to bend and deform. The amount of bending deformation occurring in the part can be reduced. As a result, the amount of bending deformation generated in the bending portion is reduced to ensure good insertability and operability, thereby preventing an increase in the amount of bending force.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.

(1) In an endoscope having a flexible tube provided with a resin-made outer skin layer in an endoscope insertion portion, and an elongated tube body inserted in the endoscope insertion portion,
An endoscope in which the amount of contraction of the tube body after the high-temperature and high-pressure steam sterilization step is set to be equal to or greater than the amount of contraction of the flexible tube.

(2) The endoscope according to appendix 1, wherein the tube body is a channel tube constituting a treatment instrument insertion channel.

(3) The endoscope according to appendix 1, wherein the tube body is a channel tube for air supply and water supply.

(4) The endoscope according to appendix 1, wherein the outer skin layer is formed of any of an ester thermoplastic elastomer, an amide thermoplastic elastomer, a styrene resin, a fluorine rubber, a silicon rubber, or a resin blended with these. .

  By these things, a tube body does not sag and meander after the heat load of a high-temperature / high pressure steam sterilization process.

(5) The endoscope according to appendix 1, wherein the set temperature in the high-temperature and high-pressure steam sterilization step is a temperature range of approximately 115 ° C to approximately 140 ° C.

(6) A spiral tube formed by spirally winding a metal strip on the endoscope insertion portion, a mesh tube that covers the outer periphery of the spiral tube, and a resin outer skin layer that covers the outside of the mesh tube In an endoscope having an insertion portion with a provided flexible tube,
An endoscope in which the outer diameter of the flexible tube is the same as or smaller than that before receiving the heat load at normal temperature after receiving the heat load of the high-temperature and high-pressure steam sterilization process.

(7) The endoscope according to appendix 6, wherein when forming the flexible tube, the spiral tube is formed in a state in which the diameter is expanded in advance with respect to a natural state.

(8) The endoscope according to appendix 6, wherein when forming the flexible tube, the spiral tube is squeezed with the mesh tube.

  By these things, the outer diameter size of the flexible tube at the normal temperature after the heat load in the high-temperature and high-pressure steam sterilization step is equal to or smaller than that before receiving the heat load.

(9) The endoscope according to appendix 1 or appendix 6, wherein the set temperature in the high-temperature and high-pressure steam sterilization step is a temperature range of approximately 115 ° C to approximately 140 ° C.

(10) In an endoscope having a curved portion provided with a resin outer skin layer, which is provided on the distal end side of an insertion portion through which an elongated built-in object is inserted, and is bent by remote operation from the hand side.
Of the built-in object in the bending portion and the outer skin layer of the bending portion, a member having a high bending rigidity in the insertion portion longitudinal direction is subjected to a high-temperature and high-pressure steam sterilization process in a state where the bending portion is bent after the heat load. An endoscope configured with a member that has a relatively small amount of bending deformation at room temperature relative to the other member.

(12) The endoscope according to appendix 10, wherein the hard member is the built-in object.

(13) The endoscope according to appendix 11, wherein the built-in object is a fluid transfer conduit.

(14) The endoscope according to appendix 11, wherein the built-in object is a treatment instrument insertion channel. (15) The endoscope according to appendix 10, wherein the member having a high hardness is the curved portion skin layer.

(16) The endoscope according to appendix 10, wherein the set temperature in the high-temperature and high-pressure steam sterilization step is a temperature range of approximately 115 ° C to approximately 140 ° C.

1 to 3 relate to a first embodiment of the present invention, and FIG. 1 is a diagram for explaining a schematic configuration of an endoscope apparatus. The figure explaining the structure of a flexible tube The figure explaining the built-in thing inserted in a flexible tube The figure explaining the state of a spiral tube The figure explaining the relationship between a spiral tube and a mesh tube The figure explaining the structure of a bending part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus 15 ... Flexible tube
15a ... spiral tube
15c ... outer skin layer
21 ... Bending wire
22 ... Wire-coated coil 24 ... Light guide 25 ... Air / water tube
26 ... treatment instrument channel tube
27 ... Signal cable

Claims (3)

Insertion provided with a flexible tube provided with a spiral tube formed by spirally winding a metal strip, a mesh tube covering the outer periphery of the spiral tube, and a resin outer layer covering the outside of the mesh tube In an endoscope that has a part and is sterilized at high temperature and high pressure steam for a predetermined time at a predetermined temperature after use ,
At the time of forming the flexible tube, by forming the spiral tube in a state in which the diameter of the spiral tube is expanded in advance with respect to a natural state, when the outer skin layer is softened under the heat load during the high-temperature high-pressure steam sterilization , An endoscope characterized in that a force in a direction of reducing the diameter acts on a helical tube . 2. The molding according to claim 1, wherein when forming the flexible tube, the mesh tube is formed in a state of being tightly coated on the spiral tube so that the outer diameter of the spiral tube is in a natural state . Endoscope. The temperature is set to a predetermined temperature in a range of 115 degrees to 142 degrees, and the time is set to a predetermined time between 3 minutes and 100 minutes among the conditions of the high-temperature and high-pressure steam sterilization. 1. The endoscope according to 1.

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