Patent Publication Number: US-2018042456-A1

Title: Attachment unit

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of PCT/JP2016/055180 filed on Feb. 23, 2016 and claims benefit of Japanese Application No. 2015-113342 filed in Japan on Jun. 3, 2015, the entire contents of which are incorporated herein by this reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an attachment unit attached to an insertion section of an insertion device, which is inserted into a tested part, and capable of rotating around an axis of the insertion section. 
     2. Description of the Related Art 
     Endoscopes are used in a medical field, an industrial field, and the like. 
     The endoscope for medical use can perform observation of organs and the like by inserting an insertion section into a body, which is a tested part. 
     A general endoscope includes an operation section and an insertion section. The insertion section of the endoscope is inserted into a digestive organ digestive tract per anum, per os, or per nasal. The insertion section is extended from the operation section. A flexible tube section having flexibility, a bending section bendable in a left-right direction and an up-down direction, and a distal end section are concatenated in order from the operation section side. 
     Operation buttons, a bending operation knob, and the like, which a surgeon can operate with gripping fingers, are provided in the operation section. The bending section of the insertion section is bent in the up-down and left-right directions according to operation of the bending operation knob provided in the operation section. 
     When the surgeon inserts the insertion section into, for example, an intestinal tract, the surgeon performs twisting operation or feeding operation of the insertion section located outside a body and advances the insertion section toward an intestinal tract depth while operating the bending operation knob provided in the operation section to bend the bending section. 
     However, the intestinal tract is soft and long and complexly curves. The intestinal tract is not firmly fixed in the body. Therefore, even if the surgeon advances the insertion section while compressing the intestinal tract making full use of the twisting operation, the feeding operation, the operation for bending the bending section, and the like, the insertion section is sometimes returned to an original position of the insertion section by a reaction from the compressed intestinal tract that is returning to an original state of the intestinal tract. 
     In particular, the reaction from the intestinal tract is larger as the insertion section is inserted deeper in the intestinal tract. The surgeon needs to acquire skill to be able to cause the insertion section to reach a target intestinal tract depth while retaining a compressed state. 
     Japanese Patent No. 5326049 discloses an attachment unit attached to an insertion section in a state in which the attachment unit is rotatable around a longitudinal axis. The attachment unit includes a tube main body extended along the longitudinal axis and a fin section spirally extended along the longitudinal axis in an outer circumferential section of a tube main body. 
     The fin section of the attachment unit rotatably attached to the insertion section comes into contact with a lumen wall when the insertion section is inserted into a lumen such as a large intestine. In a state of the contact, when the tube main body of the attachment unit is rotated, for example, clockwise around the longitudinal axis of the insertion section when viewed from a proximal end side of the insertion section, propulsion for advancing the insertion section to a distal end side is given from the attachment unit to the insertion section. On the other hand, when the tube main body is rotated counterclockwise, propulsion for retracting the insertion section to a proximal end side is given from the attachment unit to the insertion section. 
     With the endoscope in which the attachment unit is attached to the insertion section, when the surgeon performs hand-side operation for advancing the insertion section, the surgeon is capable of smoothly causing the insertion section to reach the intestinal tract depth by obtaining the propulsion for advancing the insertion section to the distal end side. 
     In the attachment unit, the fin section includes a first width dimension section and a second width dimension section. A width dimension of the second width dimension section is set smaller than a width dimension of the first width dimension section. The second width dimension section bends when an external force acts on the fin section in a direction parallel to the longitudinal axis. 
     Therefore, an outer diameter dimension to an outer circumferential end of the fin section changes to a diameter smaller than an original dimension in a bent state. 
     SUMMARY OF THE INVENTION 
     An attachment unit in an aspect of the present invention includes: a unit main body attached to an insertion section of an insertion device, which is inserted into a lumen, and disposed to be rotatable around a longitudinal axis of the insertion section; and an elastic convex section protrudingly provided to be fixed in an erected state by bonding or welding on an outer circumferential surface of the unit main body and spirally extended along a longitudinal axis of the unit main body, the elastic convex section being made of an elastic member having flexibility and elasticity decided in advance. A first force amount necessary for bringing down the elastic convex section toward a distal end side of the insertion section is set to a force amount larger than reaction from a lumen wall compressed on an insertion section proximal end side of the elastic convex section returning to an original state when the insertion section is advanced toward a lumen depth while the lumen wall is compressed, a second force amount necessary for bringing down the elastic convex section toward the proximal end side of the insertion section is set to a force amount smaller than an external force given to the elastic convex section from the lumen wall when the insertion section is advanced toward the lumen depth, and the first force amount is set to be larger than the second force amount. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram for explaining an endoscope system including an endoscope and an attachment unit; 
         FIG. 2  is a diagram for explaining the endoscope in which the attachment unit is attached to an insertion section; 
         FIG. 3  is a sectional view indicated by a Y 3 -Y 3  line in  FIG. 2  and is a diagram for explaining a relation between a unit main body and a fin section configuring the attachment unit; 
         FIG. 4  is a diagram for explaining an electric driving source that rotates the attachment unit and the unit main body of the attachment unit; 
         FIG. 5  is a Y 4 -Y 4  line sectional view of  FIG. 4 ; 
         FIG. 6A  is a diagram showing a state in which the insertion section provided with the attachment unit is inserted into a large intestine; 
         FIG. 6B  is a diagram showing a state in which the rotating attachment unit advances the insertion section while drawing in a lumen wall; 
         FIG. 6C  is a diagram showing a state in which the lumen wall is further drawn in and the insertion section is further advanced toward a depth; 
         FIG. 6D  is a diagram showing a state in which a distal end portion of the insertion section provided with the attachment unit reaches a depth of the large intestine; 
         FIG. 7A  is an explanatory diagram for explaining another configuration example in which the fin section less easily falls toward an insertion section distal end side direction and is an explanatory diagram showing a configuration example in which the fin section is fixed to an outer surface of a tube main body using a first adhesive and a second adhesive; 
         FIG. 7B  is an explanatory diagram for explaining another configuration example in which the fin section less easily falls toward the insertion section distal end side direction and is an explanatory diagram showing a configuration example in which the fin section is fixed to the outer surface of the tube main body using the first adhesive; 
         FIG. 8A  is an explanatory diagram for explaining another configuration example in which the fin section less easily falls toward the insertion section distal end side direction and is an explanatory diagram showing an example in which an adhesive is applied along a longitudinal direction on a first side surface side and a second side surface side of a fin member; 
         FIG. 8B  is an explanatory diagram for explaining another configuration example in which the fin section less easily falls toward the insertion section distal end side direction and is an explanatory diagram showing an example in which the adhesive is applied to a fixed surface to fix the fin member to the tube main body with the adhesive; 
         FIG. 8C  is an explanatory diagram for explaining another configuration example in which the fin section less easily falls toward the insertion section distal end side direction and is an explanatory diagram showing an example in which the adhesive is applied to only an insertion section distal end side of the fixed surface to bond and fix the fin member to the outer surface of the tube main body; 
         FIG. 9A  is an explanatory diagram for explaining another configuration example of the fin member and is an explanatory diagram showing a configuration example in which the fin member includes, along a longitudinal axis, a hollow section having a sectional shape decided in advance; 
         FIG. 9B  is an explanatory diagram for explaining another configuration example of the fin member and is an explanatory diagram showing an example in which two elastic members are integrally configured; 
         FIG. 9C  is an explanatory diagram for explaining another configuration example of the fin member and is an explanatory diagram showing an example in which a hollow section is provided in the fin member; 
         FIG. 10A  is an explanatory diagram for explaining an example of fixing of the fin member to the unit main body and is an explanatory diagram showing an example in which the fin member is bonded and fixed by an adhesive applied to a first side surface and an adhesive applied to a second side surface; 
         FIG. 10B  is an explanatory diagram showing an example in which a first elastic member is formed thick and a second elastic member is formed thin; 
         FIG. 10C  is an explanatory diagram showing an example in which a hollow section is provided in the fin member; and 
         FIG. 10D  is an explanatory diagram showing an example in which bonding and fixing sections are provided on the first side surface side and the second side surface side of the fin member. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     An embodiment of the present invention is explained below with reference to the drawings. 
     Note that, in the figures referred to below in the explanation, scales are sometimes differentiated for each of components to show the components in recognizable sizes on the drawings. That is, the present invention is not limited to only numbers of the components, shapes of the components, ratios of the sizes of the components, and relative positional relations among the components described in the figured. 
     In the present embodiment, an insertion device is an endoscope  2  shown in  FIG. 1 . Therefore, a main part of an endoscope system  1  is configured to include the endoscope  2  and a light source device  11 , a processor for display  12 , a monitor  13 , and a control device  14 , which are endoscope external devices. 
     The endoscope  2  includes an insertion section  3  explained below. An attachment unit for an endoscope (hereinafter abbreviated as attachment unit)  30  explained below is provided in the insertion section  3 . 
     Reference numeral  15  denotes a connection cable, which electrically connects the light source device  11  and the control device  14 . The control device  14  incorporates a control section (not shown in the figure) for, for example, electrically controlling the attachment unit  30  to be driven. 
     Reference numeral  40  denotes an external switch, which includes a foot-switch connecting section  41 , a foot switch cable  42 , and a foot switch section  43 . The foot-switch connecting section  41  is configured to be detachably attachable to a foot-switch connection port  14   r  of the control device  14 . 
     Reference numeral  46  denotes an electric cable, which includes a first connecting section  47  and a second connecting section  48 . The first connecting section  47  is detachably attachable to an electric connecting section (reference sign  4   c  in  FIG. 4 ) provided in an operation section  4  explained below. The second connecting section  48  is detachably attachable to a cable connection port  14   s  of the control device  14 . 
     The light source device  11  is electrically connected to the processor for display  12  by a not-shown connection cable. The processor for display  12  is electrically connected to the monitor  13 . 
     The endoscope  2  includes the elongated insertion section  3  inserted into digestive organ digestive tracts such as an esophagus, a stomach, a duodenum, a small intestine, and a large intestine. The operation section  4  is provided at a proximal end of the insertion section  3 . A universal cord  5  extends from the operation section  4 . 
     A connection connector  6  is provided at an extension end of the universal cord  5 . The connection connector  6  is configured to be detachably attachable to a connector connecting section  11   s  of the light source device  11 . 
     In the present embodiment, the endoscope  2  is, for example, an endoscope for a lower digestive tract. However, the endoscope  2  is not limited to the endoscope for a lower digestive tract and may be, for example, an endoscope for upper digestive tracts. 
     As shown in  FIG. 2 , the insertion section  3  includes a distal end portion  3   a  on a distal end side. A bending section  3   b  is provided on a proximal end side of the distal end portion  3   a.  A flexible tube section  3   c  having flexibility decided in advance is provided on the proximal end side of the bending section  3   b.  The bending section  3   b  is configured to be bendable, for example, in up-down and left-right directions. 
     Reference sign  3   d  denotes a passive bending section. 
     As shown in  FIG. 1 , an up-down bending operation knob  4 UD and a left-right bending operation knob  4 RL, which are bending operation devices, are provided in the operation section  4 . The respective operation knobs  4 UD and  4 RL are configured to be respectively turnable around not-shown axes. 
     Like a bending section of an endoscope in the past, a bending wire (not shown in the figure) is towed according to operation of the up-down bending operation knob  4 UD or the left-right bending operation knob  4 RL, whereby the bending section  3   b  bends in a desired direction. 
     As shown in  FIG. 1  and  FIG. 2 , the attachment unit  30  is provided in a distal end side outer circumference of the flexible tube section  3   c  configuring the insertion section  3 . The attachment unit  30  is a driven section and is disposed to be turnable around a longitudinal axis of the insertion section  3  to perform a first motion and a second motion. 
     The first motion is a rotating motion for generating first propulsion for advancing the insertion section  3  toward the distal end side, that is, toward an intestinal tract depth. On the other hand, the second motion is a rotating motion for generating second propulsion for retracting the insertion section  3  toward the proximal end side, that is, from an inside of a body to an outside. 
     In the present embodiment, the attachment unit  30  is configured to rotate clockwise or counterclockwise according to operation of an external switch  40 , when viewed from the proximal end side of the insertion section  3  around a longitudinal axis  3 Aa of the insertion section  3  shown in  FIG. 2 . 
     The passive bending section  3   d  is configured to passively bend by receiving an external force. In the present embodiment, the passive bending section  3   d  is disposed between the bending section  3   b  and the flexible tube section  3   c  configuring the insertion section  3 . 
     In the present embodiment, the flexible tube section  3   c  is configured of a first flexible tube  3   c   1  and a second flexible tube  3   c   2 . The first flexible tube  3   c   1  is located on the passive bending section  3   d  side. The second flexible tube  3   c   2  is connected to a proximal end of the first flexible tube  3   c   1 . 
     The bending section  3   b  and the passive bending section  3   d  are connected via a first connection tube  3   e   1 . 
     The passive bending section  3   d  and the first flexible tube  3   c   1  are connected via a second connection tube  3   e   2 . The first flexible tube  3   c   1  and the second flexible tube  3   c   2  are connected via a third connection tube  3   e   3 . 
     As shown in  FIG. 2  and  FIG. 3 , the attachment unit  30  includes a tube main body  31 , which is a unit main body, and a fin section  32 , which is an elastic convex section. 
     The fin section  32  projects from an outer surface of the tube main body  31  toward a radial direction outer side of the tube main body  31  by an amount decided in advance. The fin section  32  is provided to spirally extend on the outer surface of the tube main body  31 . An angle a of the spiral fin section  32  with respect to an axis  3 Aa is set to, for example, an angle larger than 45°. 
     The tube main body  31  is a tube made of resin such as polyurethane and has flexibility and elasticity decided in advance. The tube main body  31  has an inner diameter for disposing the tube main body  31  in a state in which the tube main body  31  loosely fits in the outer circumferential surface of the insertion section  3 . 
     A distal end portion of the tube main body  31  is disposed in a not-shown attachment groove of the first connection tube  3   e   1  also functioning as an attaching section of an insertion supporting mechanism section. On the other hand, as explained below, a proximal end section of the tube main body  31  is disposed in an attachment groove (see reference sign  3   g  in  FIG. 4 ) of the third connection tube  3   e   3  also functioning as the attaching section of the insertion supporting mechanism section. 
     With this configuration, the tube main body  31  is rotatable clockwise and counterclockwise with respect to the insertion section  3 . 
     The attachment unit  30  is configured to give propulsion generated by screw action due to contact of the spiral fin section  32  with a lumen wall to the insertion section  3  when the tube main body  31  is rotated in a winding direction around an axis or in an opposite direction of the winding direction with respect to the insertion section  3 . 
     More specifically, in a state in which the fin section  32  is in contact with the lumen wall, when the tube main body  31  is rotated around the axis, that is, clockwise (right-handed), which is the same as the winding direction of the fin section  32 , when viewed from the operation section  4  side, the attachment unit  30  of the present embodiment gives first propulsion for advancing the insertion section  3  toward a body cavity depth to the insertion section  3 . 
     Conversely, in the state in which the fin section  32  is in contact with the lumen wall, when the tube main body  31  is rotated counterclockwise (left-handed), which is an opposite direction of the winding direction of the fin section  32  when viewed from the operation section  4  side, the attachment unit  30  gives second propulsion for retracting the insertion section  3  toward the outside of the body to the insertion section  3 . 
     As shown in  FIG. 3 , in the present embodiment, the fin section  32  is formed by fixing a fin member  60  on the outer surface of the tube main body  31 . That is, the fin member  60  is a member different from the tube main body  31 . 
     The fin member  60  is an elongated and solid elastic bar-like member made of, for example, rubber having flexibility and elasticity decided in advance. A sectional shape of the fin member  60  is formed in a shape decided in advance. 
     The fin member  60  includes a fixed surface  61  and a contact surface  62 . The fixed surface  61  is a surface disposed on the outer circumferential surface of the tube main body  31 . On the other hand, the contact surface  62  is an outer side surface excluding the fixed surface  61  and is a surface in contact with the lumen wall. A ridge line where an upper surface  62   u  of the contact surface  62  and side surfaces  62   s   1  and  62   s   2  disposed across the upper surface  62   u  cross is chamfered and rounded. 
     As shown in  FIG. 2  and  FIG. 3 , the fixed surface  61  of the fin member  60  is disposed in an erected state on the outer surface of the tube main body  31 . In this disposition state, the fin member  60  is spirally extended along a longitudinal axis  31   a  of the tube main body  31 . 
     In the present embodiment, the fin member  60  is bonded and fixed to the outer surface of the tube main body  31  by a first adhesive  71  and a second adhesive  72 . The first adhesive  71  is applied to the first side surface  62   s   1 , which is the proximal end side (an arrow Yr direction side in  FIG. 3 ), along a longitudinal axis. On the other hand, the second adhesive  72  is applied to the second side surface  62   s   2 , which is the distal end side (an arrow Yf direction side in  FIG. 3 ), along a longitudinal direction. The fin member  60  is bonded and fixed to the outer surface of the tube main body  31 , whereby the fin section  32  is provided in the tube main body  31 . 
     The fin section  32  is a spiral wound clockwise (right-handed) from the operation section  4  side toward the distal end side when viewed from the proximal end side. 
     In the present embodiment, the first adhesive  71  and the second adhesive  72  are different adhesives. Hardness of an adhesive hardened section formed by hardening of an adhesive is different in the first adhesive  71  and the second adhesive  72 . 
     More specifically, hardness of a first hardened section, in which the first adhesive  71  hardens, is set higher than hardness of a second hardened section formed by hardening of the second adhesive  72 . 
     In this way, the fin member  60  is bonded and fixed to the tube main body  31  by the first adhesive  71  and the second adhesive  72 . Consequently, a hard fixed section  70 H, which is the first hardened section formed by the hardening of the first adhesive  71 , is provided on the distal end side of the fin section  32 . A soft fixed section  70 S, which is the second hardened section formed by the hardening of the second adhesive  72 , is provided on the proximal end side of the fin section  32 . 
     Note that a sectional area of the hard fixed section  70 H and a sectional area of the soft fixed section  70 S have the same shape. 
     The hard fixed section  70 H is provided on the distal end side of the fin section  32  fixed to the tube main body  31  by bonding in this way, and consequently, the fin section  32  less easily falls to the distal end side. 
     On the other hand, the soft fixed section  70 S is provided on the proximal end side along the longitudinal axis  31   a  of the fin section  32 , and consequently, the fin section  32  easily falls to the proximal end side. 
     Therefore, a first force amount F 1  necessary for bringing down the fin section  32  to the distal end side and a second force amount F 2  necessary for bringing down the fin section  32  to the proximal end side are different force amounts. 
     To bring down the fin section  32  to the distal end side, a force amount larger than a force amount for bringing down the fin section  32  to the proximal end side is necessary. That is, the first force amount F 1  is a force amount larger than the second force amount F 2 . 
     In the present embodiment, when the insertion section  3  is advanced toward an intestinal tract depth while an intestinal tract is compressed, the first force amount F 1  is a force amount larger in advance than reaction from the compressed intestinal tract returning to an original state. 
     On the other hand, the second force amount F 2  is a force amount with which the fin section  32  is bent by an external force given to the fin section  32  from an intestinal tract wall when the insertion section  3  is advanced toward the intestinal tract depth. 
     With this configuration, the fin section  32  erected on the tube main body  31  is prevented from being brought down to the distal end side by the reaction from the compressed intestinal tract wall when the insertion section  3  advances to the intestinal tract depth. 
     Note that the tube main body  31  of the attachment unit  30  is rotated clockwise or counterclockwise by, for example, a driving motor  45 , which is an electric driving source, disposed in the operation section  4  as shown in  FIG. 4 . 
     The driving motor  45  generates a rotation driving force for rotating the attachment unit  30 . A driving shaft  45   a  of the driving motor  45  is rotatable clockwise or counterclockwise around an axis when viewed from a motor proximal end side as indicated by an arrow Y 4 . 
     A clockwise rotation driving force or a counterclockwise rotation driving force is transmitted to the attachment unit  30  by a driving shaft  50 , which is a rotation driving force transmitting member. 
     The driving shaft  50  is inserted through and disposed in the flexible tube section  3   c  of the endoscope  2  along a longitudinal axis in a state in which the driving shaft  50  is covered by a soft protection tube  53 . A first end portion  51  of the driving shaft  50  projects further than a first side end  53   a  of the protection tube  53 . A second end portion  52  projects further than a second side end  53   b  of the protection tube  53 . 
     The driving shaft  50  is a flexible shaft having flexibility decided in advance and is formed by winding a special hard steel wire or a stainless steel wire for spring alternately in right winding and left winding in several layers. 
     The first end portion  51 , which is an end portion disposed in the operation section  4 , of the driving shaft  50  is coupled to the driving shaft  45   a  of the motor  45 . More specifically, a coupling section  45   j  is integrally fixed in the driving shaft  45   a  of the motor  45 . The first end portion  51  of the driving shaft  50  is integrally fixed to a coupling rod  45   r.  The coupling rod  45   r  is engaged and arranged in the coupling section  45   j  to be capable of advancing and retracting in a longitudinal axis direction and capable of transmitting torque to the coupling section  45   j.    
     The attachment unit  30  is configured to rotate clockwise or counterclockwise when viewed from the proximal end side of the operation section  4  according to switch operation of the external switch  40 . 
     Note that the motor  45  is in a stopped state, for example, when the foot switch section  43  is in a non-step-in state. Rotating speed of the motor  45  may change according to magnitude of a step-in amount of the foot switch section  43 . 
     With the endoscope system  1  explained above, an instruction signal is outputted to the control section of the control device  14  when the surgeon steps in the foot switch section  43 . The control section generates a motor driving signal. The generated motor driving signal is outputted from the control device  14  to the motor  45  via the electric cable  46 . As a result, the driving shaft  45   a  of the motor  45  is rotated clockwise or counterclockwise around the axis. 
     Then, the driving shaft  50  starts rotation according to the clockwise or counterclockwise rotation of the driving shaft  45   a  of the motor  45 . That is, the driving shaft  45   a  of the motor  45  is driven to rotate clockwise, whereby the driving shaft  50  rotates in the same direction. The driving shaft  45   a  is driven to rotate counterclockwise, whereby the driving shaft  50  rotates in the same direction. 
     Note that a signal line connected to an encoder for motor  45 E is inserted through the electric cable  46 . The encoder for motor  45 E detects a rotating direction and rotating speed of the motor  45  and outputs a detection signal to the control section of the control device  14  via the signal line in the electric cable  46 . 
     On the other hand, the second end portion  52 , which is an end portion disposed in the flexible tube section  3   c , of the driving shaft  50  is integrally fixed to a transmission gear  35 . As shown in  FIG. 4  and  FIG. 5 , the transmission gear  35  meshes with a gear section  33   g.  The gear section  33   g  is formed on an inner circumferential surface of an annular tube-main-body rotating section  33 . 
     With this configuration, the transmission gear  53  is rotated in the same direction according to the rotation of the driving shaft  50 . The tube-main-body rotating section  33  is rotated in the same direction according to the rotation of the transmission gear  35 . 
     Note that the driving shaft  50  is not limited to the flexible shaft and may be a torque coil, which is a multi-line multi-layer coil, a torque wire, or the like as long as torsional rigidity at the time when the driving shaft  50  is rotated in the winding direction and torsional rigidity at the time when the driving shaft  50  is rotated in the opposite direction of the winding direction are different. 
     An outer circumferential surface of the tube-main-body rotating section  33  is integrally fixed to the tube main body  31  of the attachment unit  30 . The gear section  33   g  is disposed to pass through a through-hole  3   h,  which causes an inside and an outside to communicate, provided in the third connection tube  3   e   3  and project outward from an outer circumferential surface of the third connection tube  3   e   3 . 
     The width of the through-hole  3   h  is set to a dimension decided in advance taking into account a thickness dimension of the transmission gear  35  in order to restrict movement in the axis direction of the transmission gear  35 . 
     Reference numeral  36  denotes an O-shaped ring. A pair of O-shaped rings  36  is disposed in close contact with an inner circumferential surface of the tube-main-body rotating section  33  and disposed in close contact with an outer circumferential surface of the third connection tube  3   e   3 . 
     The tube-main-body rotating section  33  is integral with the tube main body  31  of the attachment unit  30  capable of turning with respect to the insertion section  3 . 
     With this configuration, water tightness between the inner circumferential surface of the tube-main-body rotating section  33  and the outer circumferential surface of the third connection tube  3   e   3  is maintained. 
     Action of the attachment unit  30  is explained with reference to  FIGS. 6A to 6D . 
     In the present embodiment, the surgeon performs hand-side operation and inserts the insertion section  3 , for example, from an anus  101  shown in  FIG. 6A  toward a depth  103  of a large intestine  102 , a depth of a not-shown small intestine, or the like while observing an endoscopic image displayed on the monitor  13 . 
     At this point, the surgeon operates a changeover switch of the foot switch section  43  according to necessity to advance the insertion section  3  while obtaining the first propulsion. 
     The attachment unit  30  shown in  FIG. 6B  advances while giving the first propulsion to the insertion section  3  and drawing in a lumen wall  102   w  of the large intestine  102 . At this point, the drawn-in lumen wall  102   w  is compressed while being collected to the proximal end side of the attachment unit  30  to be a lumen-wall compressed section  102   p   1 . Reaction P 1  from the lumen-wall compressed section  102   p   1  returning to an original state acts toward the attachment unit  30  from the lumen-wall compressed section  102   p   1 . 
     The insertion section  3  further advances with the first propulsion, whereby the lumen wall  102   w  is further drawn in to the proximal end side than the attachment unit  30  as shown in  FIG. 6C . A compressed lumen-wall compressed section  102   p   2  is provided. Reaction P 2 , which is a force amount larger than the reaction P 1  from the lumen-wall compressed section  102   p   1  returning to the original state, acts toward the attachment unit  30  from the lumen-wall compressed section  102   p   2 . 
     As the insertion section  3  is advanced by the first propulsion, a lumen-wall compressed section drawn in to the proximal end side of the attachment unit  30  increases and reaction from the lumen-wall compressed section returning to an original state acting toward the attachment unit  30  from the lumen-wall compressed section also increases. 
     As shown in  FIG. 6D , the distal end portion  3   a  of the insertion section  3  reaches the depth  103 , which is a target part. At this point, a lumen-wall compressed section  102 P is provided on the proximal end side of the attachment unit  30 . Reaction PN acts toward the attachment unit  30  from the lumen-wall compressed section  102 P. 
     In the present embodiment, the fin section  32  of the attachment unit  30  is set to fall to the distal end side with the first force amount. The first force amount is set to a force amount larger than reaction PN assumed in advance. 
     As a result, in a state in which the distal end portion  3   a  of the insertion section  3  reaches the depth  103 , the fin section  32  of the attachment unit  30  is prevented from being brought down by the reaction PN acting toward the attachment unit  30  from the lumen-wall compressed section  102 P. 
     Therefore, the fin section  32  can continue to hold, in a compressed state, the lumen-wall compressed section  102 P located on the proximal end side of the fin section  32 . In other words, it is possible to prevent a situation in which, before the distal end portion  3   a  of the insertion section  3  reaches the depth  103 , the fin section  32  of the attachment unit  30  is brought down by reaction acting toward the attachment unit  30  from the lumen-wall compressed section  102 P, the lumen-wall compressed section compressed and disposed on the proximal end side of the attachment unit  30  climbs over the fin section  32 , and the insertion section  3  is returned to an original position. 
     Note that the fin section  32  is set to fall to the proximal end side with the second force amount. The second force amount is set to a force amount acting on the fin section  32  from the lumen wall when the fin section  32  passes, with the first propulsion, a small-diameter lumen having a dimension decided in advance. 
     In this way, the fin member  60  is bonded and fixed to the tube main body  31  with the first adhesive  71  and the second adhesive  72 , whereby the hard fixed section  70 H is provided on the distal end side of the fin section  32  and the soft fixed section  70 S is provided on the proximal end side. 
     The first force amount for bringing down the fin section  32  to the distal end side is set to a force amount larger than the reaction PN assumed in advance. For this reason, it is possible to prevent the fin section  32  from being brought down to the distal end side by the reaction PN from the lumen-wall compressed section  102 P disposed in the compressed state on the proximal end side of the fin section  32  and advance the distal end portion  3   a  of the insertion section  3  toward a target depth while giving the first propulsion to the insertion section  3  from the attachment unit  30 . 
     When the insertion section  3  is advanced by the first propulsion and when a force amount larger than the second force amount is caused to act on the proximal end side of the fin section  32  from a body cavity wall, the fin section  32  is bent to the proximal end side and the insertion section  3  can smoothly advance. 
     Note that the first force amount is set to a value set as appropriate according to a distance to a target part into which the insertion section is inserted, a state of a tube section into which the insertion section is inserted, and the like assuming reaction of the compressed lumen wall returning to an original state and with reference to the reaction. 
     In the embodiment explained above, the fin section  32  is configured by applying the first adhesive  71  to the first side surface  62   s   1  side of the fin member  60  and applying the second adhesive  72  to the second side surface  62   s   2  side to bond and fix the fin member  60  to the tube main body  31 . However, the fin section  32  that less easily falls to the distal end side with the reaction from the lumen-wall compressed section in the compressed state and easily falls to the proximal end side taking into account insertability of the insertion section may be configured as shown in  FIG. 7A  to  FIG. 10D  referred to below. 
     The fin section  32  shown in  FIG. 7A  is configured by applying the first adhesive  71  along the longitudinal axis on a distal end side of the fixed surface  61  and applying the second adhesive  72  along the longitudinal axis on a proximal end side Yr of the fixed surface  61  to bond and fix the fin member  60  to the outer surface of the tube main body  31 . 
     With this configuration, the distal end side of the fin section  32  is the hard fixed section  70 H and the proximal end side of the fin section  32  is the soft fixed section  70 S. As a result, the fin section  32  less easily falls to the distal end side and easily falls to the proximal end side. Consequently, it is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     Note that, as shown in  FIG. 7B , the fin section  32  may be configured by applying the first adhesive  71  along the longitudinal axis only on the distal end side of the fixed surface  61  to bond and fix the fin member  60  to the outer surface of the tube main body  31 . As a result, the fin section  32  less easily falls to the distal end side and easily falls to the proximal end side. Therefore, it is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     The fin member  60  configuring the fin section  32  shown in  FIGS. 8A to 8C  is fixed to the outer surface of the tube main body  31 ; as shown in  FIG. 8A , an adhesive  73  is applied along the longitudinal axis on the first side surface  62   s   1  side and the second side surface  62   s   2  side of the fin member  60 . The fin member  60  is bonded and fixed to the outer surface of the tube main body  31  by the adhesive  73  to be configured as the fin section  32 . 
     In the present embodiment, a sectional area of an adhesive hardened section provided on the distal end side of the fin section  32  and a sectional area of an adhesive hardened section provided on the proximal end side are different. More specifically, a sectional area of a first fixed section, which is the adhesive hardened section on the distal end side, is larger than a sectional area of a second fixed section, which is the adhesive hardened section on the proximal end side, in advance. 
     In this way, a large fixed section  70 L functioning as the first fixed section having the large sectional area is provided on the distal end side of the fin section  32 . A small fixed section  70   s  functioning as a second fixed section having a sectional area smaller than the sectional area of the large fixed section  70 L is provided on the proximal end side. 
     As a result, the fin section  32  including the large fixed section  70 L and the small fixed section  70   s  less easily falls to the distal end side and easily falls to the proximal end side. Therefore, it is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     It is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  to cope with an assumed force amount by setting a size of the sectional area of the large fixed section  70 L and a size of the sectional area of the small fixed section  70   s  as appropriate. 
     Note that the adhesive  73  may be applied to the fixed surface  61  to bond and fix the fin member  60  to the tube main body  31 . In this case, as shown in  FIG. 8B , the large fixed section  70 L, in which the area of the adhesive hardened section is large, is provided on the distal end side Yf of the fixed surface  61  and the small fixed section  70   s,  in which the area of the adhesive hardened section is smaller than the large fixed section  70 L, is provided on the proximal end side Yr. 
     With this configuration, the fin section  32  less easily falls to the distal end side and easily falls to the proximal end side. It is possible to obtain the same action and effects as the action and effects in the embodiment. 
     As shown in  FIG. 8C , the adhesive  73  may be applied only to the distal end side of the fixed surface  61  to bond and fix the fin member  60  to the outer surface of the tube main body  31 . As a result, the fin section  32  less easily falls to the distal end side and easily falls to the proximal end side. It is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     In  FIG. 9A  to  FIG. 9C , the fin section  32  is configured by bonding and fixing fin members  60 A,  60 B, and  60 C different from the fin member  60  to the tube main body  31 . In these figures, the fin members  60 A,  60 B, and  60 C are bonded and fixed to the outer surface of the tube main body  31  by one kind of, for example, the adhesive  73  applied to the fixed surface  61 . 
     The fin member  60 A shown in  FIG. 9A  is an elongated elastic member made of, for example, rubber having flexibility and elasticity decided in advance and includes a hollow section  63  having a sectional shape decided in advance along an extending direction of a spiral direction. In the figure, the hollow section  63  is a through-hole along the extending direction of the spiral direction. However, the hollow section  63  may be a longitudinal direction groove along the extending direction. An opening of the groove is provided on the fixed surface  61  side. 
     Since a thick section  64   a  and a thin section  64   b  are provided in the fin member  60 A, a hollow-section center line  63   a  of the hollow section  63  and a fin-member center line  60 Aa positionally deviate. 
     In the present embodiment, the hollow-section center line  63   a  positionally deviates further to the proximal end side than a fin-section center line  32   a  such that the thick section  64   a  is provided on the distal end side of the fin section  32  and the thin section  64   b  is provided on the proximal end side. 
     In this way, the fin member  60 A provided with the hollow section  63  is bonded and fixed to the tube main body  31  to configure the fin section  32 . Consequently, the fin section  32  less easily falls to the distal end side where the thick section  64   a  is provided and easily falls to the proximal end side where the thin section  64   b  is provided. It is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     Note that, in the fin member  60 A explained above, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  to cope with an assumed force amount by setting an opening width of the hollow section  63  as appropriate or setting a positional deviation amount between the hollow-section center line  63   a  and the fin-member center line  60 Aa as appropriate. 
     More specifically, when the opening width of the hollow section  63  is formed small and the hollow-section center line  63   a  is caused to further positionally deviate in the proximal end side, thickness of the thick section  64   a  further increases and, on the other hand, thickness of the thin section  64   b  decreases. It is possible to make the fin section  32  less easily fall to the distal end side. 
     The fin member  60 B shown in  FIG. 9B  is configured as an elongated elastic member having flexibility and elasticity decided in advance by integrating a first elastic member  65  and a second elastic member  66 , which are two elastic members. 
     The first elastic member  65  is a hard tabular elastic member with high rigidity having flexibility and elasticity decided in advance. The second elastic member  66  is a soft tabular elastic member with low rigidity compared with the first elastic member  65 . In the present embodiment, the first elastic member  65  and the second elastic member  66  have the same shape. 
     In this way, the fin member  60 B configured by integrating the first elastic member  65  and the second elastic member  66  is bonded and fixed to the tube main body  31  to configure the fin section  32 . With this configuration, the fin section  32  less easily falls to the distal end side where the first elastic member  65  is provided and easily falls to the proximal end side where the second elastic member  66  is provided. It is possible to obtain the same action and effects as the action and effects in the embodiment explained above. 
     Note that it is possible to form the first elastic member  65  and the second elastic member  66  in different shapes to adjust the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side as appropriate. More specifically, it is possible to make the fin section  32  less easily fall to the distal end side by increasing the thickness of the first elastic member  65  and reducing the thickness of the second elastic member  66  without changing the thickness of the fin member  60 . 
     In the fin member  60 B explained above, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side as appropriate by adjusting a characteristic of the first elastic member  65  and a characteristic of the second elastic member  66  as appropriate. 
     Further, as shown in  FIG. 9C , the hollow section  63  may be provided in the fin member  60 B to configure a fin member  60 C. The hollow-section center line  63   a  of the hollow section  63  coincides with the fin-member center line  60 Aa. 
     With this configuration, it is possible to perform the adjustment of the easiness of the less falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  configured of the fin member  60 C to cope with an assumed force amount by changing the opening width of the hollow section  63  provided in the fin member  60 B in addition to a combination of the first elastic member  65  and the second elastic member  66  configuring the fin member  60 B. 
     Note that, in the embodiment shown in  FIG. 8A  to  FIG. 9C , the fin member is bonded and fixed to the tube main body. However, the fin member may be integrally fixed to the tube main body by welding. 
     The adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  may be performed by combining the techniques explained above as shown in  FIG. 10A  to  FIG. 10D . 
     In  FIG. 10A , the fin member  60 A is bonded and fixed to the outer surface of the tube main body  31  by the large fixed section  70 L of the adhesive  73  applied to the first side surface  62   s   1  and the small fixed section  70   s  of the adhesive  73  applied to the second side surface  62   s   2 . 
     With this configuration, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  by setting, as appropriate, the opening width of the hollow section  63  of the fin member  60 A, a positional deviation amount between the hollow-section center line  63   a  of the hollow section  63  and the fin-member center line  60 Aa, the size of the sectional area of the large fixed section  70 L, and the size of the sectional area of the small fixed section  70   s.    
     A fin member  60 D shown in  FIG. 10B  is a modification of the fin member  60 B. As explained above, the first elastic member  65  and the second elastic member  66  have different shapes. The thickness of the first elastic member  65  is formed thick and the thickness of the second elastic member  66  is formed thin. 
     As in  FIG. 10A , the fin member  60 D is bonded and fixed to the outer surface of the tube main body  31  by the large fixed section  70 L and the small fixed section  70   s.    
     With this configuration, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  by setting the size of the sectional area of the large fixed section  70 L and the size of the sectional area of the small fixed section  70   s  as appropriate in addition to the thickness of the first elastic member  65  of the fin member  60 D and the thickness of the second elastic member  66 . 
     A fin member  60 E shown in  FIG. 10C  includes the hollow section  63 . The hollow-section center line  63   a  of the hollow section  63  positionally deviates further to the proximal end side than the fin-section center line  32   a  oppositely to the above description. 
     The fin member  60 E is bonded and fixed to the outer surface of the tube main body  31  by the hard fixed section  70 H provided on the distal end side and the soft fixed section  70 S provided on the proximal end side. 
     With this configuration, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  by setting the opening width of the hollow section  63  of the fin member  60 E and the positional deviation amount between the hollow-section center line  63   a  of the hollow section  63  and the fin-member center line  60 Aa as appropriate and selecting a type of the first adhesive  71  configuring the hard fixed section  70 H and a type of the second adhesive  72  configuring the soft fixed section  70 S as appropriate. 
     As shown in  FIG. 10D , bonding and fixing sections  74  are provided on the first side surface  62   s   1  side and the second side surface  62   s   2  side of the fin member  60 A shown in  FIG. 9A  to bond and fix the fin member  60 A to the outer surface of the tube main body  31 . 
     With this configuration, it is possible to perform the adjustment of the less easiness of the falling to the distal end side and the easiness of the falling to the proximal end side of the fin section  32  by setting the opening width of the hollow section  63  of the fin member  60 A, the positional deviation amount between the hollow-section center line  63   a  of the hollow section  63  and the fin-member center line  60 Aa, and a size of a sectional area of the bonding and fixing sections  74  as appropriate. 
     Note that, in the embodiment explained above, the fin is configured by providing the fin member in the tube main body. However, the fin and the tube main body may be integrally configured by two-color molding. 
     In the embodiment explained above, the fin member  60  is disposed in an erected state on the outer surface of the tube main body  31 . However, the fin member  60  may be tilted in a proximal end direction of the insertion section  3  and provided in the tube main body  31  to configure the fin section  32 . With this configuration, the fin section  32  less easily falls to the distal end side and easily falls to the proximal end side. 
     Note that the present invention is not limited only to the embodiment explained above and can be variously modified and carried out in a range not departing from the spirit of the invention. The insertion device is not limited to the endoscope and may be, for example, a treatment instrument for endoscope inserted through a treatment instrument channel of an endoscope or a guide tube that guides an endoscope into a body. In this case, the attachment unit is attached to an insertion section of the treatment instrument for endoscope or an insertion section of the guide tube.