Patent ID: 12232741

DESCRIPTION OF EMBODIMENTS

An exemplary embodiment of the present disclosure will be described with reference toFIGS.1to15.

FIG.1is a view showing an appearance of a ligation device1as a medical device according to the present embodiment. The ligation device1includes a clip unit (treatment portion)10indwelled inside the body, and an applicator50configured to operate the clip unit10. The clip unit10is attached to a tip end (distal end) of the applicator50.

FIG.2is a view showing an appearance of the clip unit10.FIG.3is a cross-sectional view of the clip unit10. As shown inFIG.2, the clip unit10includes an arm portion20and a pressing tube (holding member)30in which part of the arm portion20is accommodated.

The arm portion20has a pair of arms as a first arm21and a second arm22. The first arm21and the second arm22have claws21aand22aat distal ends thereof respectively. As shown inFIG.3, the first arm21and the second arm22are connected to each other at a proximal end portion (base)20aof the arm portion20. The proximal end portion20ais formed in a U shape.

The arm portion20is made of metal including alloy. Examples of the material of the arm portion20include stainless steel, cobalt chrome alloy, nickel titanium alloy and the like.

The first arm21and the second arm22are expanded in an initial state shown inFIG.2. When the first arm21and the second arm22approach each other from the initial state, a biasing force for restoring to the initial state is generated due to an elastic force of the material.

The pressing tube30is a tubular member formed of metal, resin, or the like. As shown inFIG.3, the proximal end portion20aof the arm portion20is accommodated in the pressing tube30. The distal end portion of the arm portion20protrudes from the distal end opening30aof the pressing tube. The proximal end opening30bof the pressing tube30is smaller than the distal end opening30a.

FIG.4is a view of the inside of the pressing tube30viewed from a direction different from that inFIG.3. As shown inFIG.4, a locking portion23is provided at an intermediate portion of each arm of the arm portion20, and a width of each arms21,22at the locking portion23is large (only the first arm21is visible inFIG.4). Each locking portion23is capable of passing through the proximal end opening30bwhen the first arm21and the second arm22approach each other. When the first arm21and the second arm22are separated from each other after passing through the proximal end opening30b, the locking portion23is impossible to pass through the proximal end opening30b. As a result, the arm portion20is locked with the pair of arms closed.

A coil spring31is arranged inside the pressing tube30. The distal end of the coil spring31may contact the proximal surfaces of the first arm21and the second arm22. The proximal end of the coil spring31may come into contact with the proximal end surface32of the pressing tube30having the proximal end opening30b.

The basic configurations of the arm portion20and the pressing tube30described above are known, for example, as disclosed in PCT International Publication No. 2014/181676.

As shown inFIG.1, the applicator50includes an elongated insertion portion51, an operation wire (power transmission member)52inserted through the insertion portion51, and an operation portion60connected to the insertion portion51.

As the insertion portion51, for example, a sheath formed of a coil may be used.

The operation portion60has a main body61connected to the insertion unit51, and a slider62slidably attached to the main body61.

For example, a stranded wire made of a metal element wire may be used as the operation wire52. A proximal end portion of the operation wire52is connected to the slider62. By moving the slider62with respect to the main body61, the operation wire52may be advanced and retracted in the insertion portion51.

FIG.5is an enlarged cross-sectional view of the distal end portion of the applicator50to which the clip unit10is attached.

A hook70that engages with the clip unit10is fixed to the distal end of the operation wire52. As shown inFIG.5, the distal end portion of the operation wire52enters the pressing tube30, and the hook70and the proximal end portion20aof the arm portion20are engaged with each other. An outer dimension of the hook70is slightly smaller than an inner diameter of the coil spring31.

In the following description, the proximal end portion20amay be referred to as the “a base20a”. The hook70and the base20aconfigure a link80that connects the applicator50and the clip unit10.

FIG.6is an enlarged view of the hook70. The hook70has a rear portion71connected to the operation wire52and a front portion72engaging with the base20a.

The rear portion71is formed in a spindle shape that gradually shrinks toward both ends in the front-rear direction, and has a bottomed hole71aopening at the rear end. The distal end portion of the operation wire52enters the hole71a. The operation wire52and the hook70are connected, for example, by brazing or the like. According to the present embodiment, the hook70and the operation wire52are connected while maintaining a coaxial state.

The front portion72has a pair of engagement arms73and74. The engagement arm73has a claw portion75that contacts the base20aand a plate-shaped portion76that connects the claw portion75and the rear portion71. Similar to the engaging arm73, the engaging arm74has a claw portion77and a plate-shaped portion78with the same shapes as those of the engaging arm73. The engagement arms73and74are provided at positions symmetrical with respect to a central axis X1of the hook70.

Hereinafter, the shape and structure of the engagement arm73will be described in detail, and the same description is applicable to the engagement arm74.

A notch751is formed on an inner surface of the claw portion75more distal than a connection portion between the plate-shaped portion76and the claw portion75. In the claw portion75, a region where the notch751is formed has a reduced bending rigidity since there is less configuration material, and the region functions as a first deformation portion752. A three-dimensional shape of the notch751is not particularly limited.

A locking surface (hook surface)753that is locked to the distal surface (base surface)754of the base20ais formed more distal than the first deformation portion752. The locking surface753extends in a direction intersecting the central axis X1in the cross section shown inFIG.6. A portion more distal than the locking surface753is formed in a tapered shape that gradually shrinks toward the distal end in the cross section shown inFIG.6.

The plate-shaped portion76extends parallel or substantially parallel to the central axis X1. Therefore, according to the present embodiment, the plate-shaped portion76extends parallelly or substantially parallelly to the operation wire52. A notch761is formed more proximal than a connection portion T between the plate portion76and the rear portion71. The plate-shaped portion76is formed to be easily deformed since the configuration material thereof is less than that of the front portion72and the rear portion71. Particularly, the plate-shaped portion76near the connection portion T is the farthest from the engaging portion between the hook70and the base20a, and a change of thickness in the connection portion T is large such that it is easy for stress to be concentrated thereto. As a result, the plate-shaped portion76near the connection site T functions as a second deformation portion762. A bending rigidity of the second deformation portion762is smaller than the bending rigidity of the first deformation portion752.

The engagement arms73and74sandwich the base20afrom a direction orthogonal to an open-close direction of the arm portion20. In the state in which the hook70and the base20aare engaged with each other, the hook surface753and the base surface754are in contact with each other more distal than the first deformation portion752. Accordingly, the first deformation portion752is closer to the hook surface753than the second deformation portion762. Furthermore, in the engagement arm73, the first deformation portion752is at a position separated from a base line B1defined as a line connecting the hook surface753and the second deformation portion762. According to the present embodiment, the base line B1is parallel to the central axis line X1.

Similar to the engagement arm73, the engagement arm74has a notch771, a first deformation portion772, a hook surface773, a notch781, and a second deformation portion782. In the engaging arm74, the first deformation portion772is at a position separated from a base line B2defined as a line connecting the hook surface773and the second deformation portion782. According to the present embodiment, the base line B2is parallel to the central axis line X1.

As shown inFIG.5, a rigid guide pipe55is attached to the distal end of the insertion portion51. An inner diameter of the distal end side region of the guide pipe55is larger than the outer diameter of the pressing pipe30, and the pressing pipe30is capable of entering the guide pipe55. A stopper56is attached to the operation wire52. Since a shape and a size of the stopper56are set such that the stopper56is impossible to enter the guide pipe55, when the stopper56comes into contact with the proximal end of the guide pipe55, the operation wire52is impossible to advance any further.

An operation when the ligation device1configured as described above is used will be described. The ligation device1is introduced into the body via a channel of an endoscope. When inserting the ligation device1into the endoscope, the user retracts the slider62by a predetermined amount to insert the ligature device1with the arm portion20closed and in an unlocked state. The clip unit10with the arm portion20closed and the distal end portion of the insertion portion51may be inserted into the endoscope while being accommodated in the outer sheath53.

When the ligation device1is protruded from the channel opening at the distal end of the endoscope, and then the pulling force with respect to the slider is reduced or the sheath is retracted, the arm portion20advances toward the pressing tube30due to its own elastic restoring force and the elastic restoring force of the coil spring31. As a result, the pair of arms21,22is in an open configuration. When the stopper56comes into contact with the rear end of the guide pipe55, the arm portion20is impossible to advance with respect to the pressing tube30, such that the arm portion20does not slip out from the pressing tube30and the open configuration is maintained.

When the user retracts the slider62with respect to the main body61, the operation wire52is pulled and the arm portion20retracts with respect to the pressing tube30, and as a result, the pair of arms21,22enter a closed configuration. The user may ligate the tissue by positioning the tissue between the pair of arms21,22and closing the pair of arms21,22. Until a locking operation described below is performed, the pair of arms21may be transitioned from the closed configuration to the open configuration again by advancing the slider62with respect to the main body61. Accordingly, in the ligation device1, until the locking operation is performed, the re-grasp of the tissue by the operation wire52operating the clip unit10may be performed.

In the guide pipe55, a restriction member57configured to prevent the connection between the base20aand the hook70from being unintentionally released is disposed. The restriction member57has a small diameter portion58having a slightly larger than the outer diameter of the hook70. In order to release the engagement between the base20aand the hook70, the engagement arms73and74have to be separated by a certain distance or more; however, there is no sufficient space in the small diameter portion58for the engagement arm73and the engagement arm74to be separated from each other. As a result, the engagement between the hook70and the base20ais not released until the engagement arms73and74pass through the small diameter portion58, and the engaged state is suitably maintained.

When it is determined that the tissue located between the pair of arms21and22may be ligated, the user performs a locking operation for fixing the arm unit20in the closed configuration. During the locking operation, the user further retracts the slider62with respect to the main body61beyond the range where the user may grasp the tissue again. When the slider62retracts, the operation wire52is pulled and the pair of arms21,22enter the pressing tube30in a substantially parallel state while clamping the tissue. Furthermore, the locking portions23provided on the pair of arms21,22respectively approach each other, and the positional relationship is determined such that they may pass through the proximal end opening30bof the pressing tube30.

The pair of locking portions23that have moved to the outside of the pressing tube30after passing through the proximal end opening30bare separated again since the force received from the operation wire52weakens, and the pair of locking portions23have a positional relationship in which they cannot pass through the proximal end opening30b. As a result, the pair of locking portions23are in contact with an edge of the proximal end opening30bso as to prevent the arm portion20from protruding from the pressing tube30, and the arm portion20is locked to maintain the closed configuration.

During the process of the locking operation, the base20aand the hook70move to the outside of the pressing tube30through the proximal end opening30b; however, the engagement state between the base20aand the hook70is suitably maintained.

When the user further retracts the slider62after the arm portion20is locked, the engagement between the base20aand the hook70is released, and the clip unit10is separated from the applicator50. Hereinafter, the operation of the hook70during the locking operation will be described in detail.

When the slider62is retracted, the operation wire52is pulled, and the traction force F applies on the hook70. In a state immediately after the hook70moves to the outside of the pressing tube30, the plate-shaped portions76,78(not shown) are parallel or substantially parallel to the central axis X1as shown inFIG.6. Accordingly, there is no moment generated for rotating the plate-shaped portions76,78due to the traction force F. Therefore, the engagement arms73and74do not rotate around the second deformation portion at this time.

FIG.7is a schematic enlarged view of the hook surface753and the base surface754. The traction force F is transmitted through the plate-shaped portion76and firstly applies on the contact portion P between the hook surface753and the base surface754(that is, the contact portion between the hook70and the base20ain the connection state) so as to generate a reaction force F1on the hook surface753.

As shown inFIG.9, since the first deformation portion752is located separated from the base line B1defined as a line passing through the contact portion P and the second deformation portion762, the reaction force F1is applied to the claw portion75as a moment. As a result, the distal end portion of the claw portion75is deformed so as to rotate around the first deformation portion752. Although it is not shown in figures, a force similar to the reaction force F1also applies on the claw77. As a result, the distal end portion of the claw portion77is deformed so as to rotate around the first deformation portion772.

Since the base lines B1and B2are parallel to the central axis line X1, the second deformation portion762and the contact portion P, and the second deformation portion782and the contact portion P are arranged parallel to the central axis line X1. Therefore, the reaction force F1does not apply on the second deformable portions762,782as a moment.

As shown inFIG.8, when the hook surface753is tilted with respect to the base surface754as a result of the claw portion75deforming around the first deformation portion752as a center, a component force F2of the reaction force F1is generated in a direction from the central axis X1toward the outside of the pressing tube30in the radial direction.

The component force F2applies in the direction of separating the engagement arm73from the base20a. That is, the component force F2applies as a moment on the second deformation portions762,782. Due to the moment, the plate-shaped portions76,78are caused to rotate around the second deformation portions762,782, respectively, such that the distal ends thereof are separated from each other. As a result, as shown inFIG.11, the claw portion75and the claw portion77are largely separated from each other, and the engagement between the hook70and the base20ais released.

In the hook70according to the present embodiment, until the component force F2is generated by the rotation of the claws75,77with the first deformation portion as the center, the rotation of the plate-shaped portions76,78with the second deformation portion as the center does not occur regardless of the amount of the traction force F. Accordingly, if the amount of the force necessary for the rotation of the claws75,77with the first deformation portion as the center is larger than the amount of the locking force in the case of clamping the hard tissue by the arm, even if the amount of the force necessary for the rotation of the plate-shaped portions76,78with the second deformation portion as the center is set to be smaller than the amount of the locking force in the case of clamping the hard tissue by the arm, there is no case in which the connection of the hook70and the base20ais released before the locking operation.

Since the hook70has the above-described configuration, by forming the second deformable portions762and782to be more easily deformed than the first deformation portions752and772, the force necessary for the rotation of the plate-shaped portions76,78with the second deformation portion as the center may be set to be significantly smaller than the locking force. As a result, after a force exceeding the locking force is applied to the claw portions75,77after the arms are locked, the plate-shaped portions76,78are rotated quickly to release the connection between the hook70and the base20a.

In this manner, in the ligation device1, it is possible to prevent the amount of operating force required for separating the clip unit10from the applicator50from becoming excessively large with respect to the amount of locking force for the arm of the clip unit10. As a result, it is possible to achieve both goals of indwelling the clip unit10while clamping the hard tissue and easy operations.

According to the present embodiment, an example in which the hook surface is orthogonal to the central axis X1in the initial state is described; however, the hook surface may not be orthogonal to the central axis X1in the initial state.

In the modification shown inFIG.12, in the initial state, the hook surface753A is inclined to form an acute angle θ1on the proximal end side with respect to the central axis X1. As a result, the contact portion P1between the hook surface753A and the base surface754is located farther from the central axis X1than the contact portion P according to the above embodiment in the cross section as shown inFIG.12. Further, the distance between the central axis X1and the contact portion P1is longer than the distance between the central axis X1and the second deformation portion762such that the base line B1is inclined and becomes nonparallel to the central axis X1.

According to the present modification, the timing at which the component force F2is generated becomes earlier than the configuration including the hook surface753according to the above embodiment and the connection is released smoothly.

According to the modification shown inFIG.13, the hook surface753B is inclined to form an obtuse angle θ2on the proximal end side with respect to the central axis X1in the initial state. As a result, the contact portion P2between the hook surface753B and the base surface754is located closer to the central axis X1than the contact portion P in the cross section shown inFIG.13. Further, the distance between the central axis X1and the contact portion P1is shorter than the distance between the central axis X1and the second deformation portion762, and the base line B1is inclined and becomes nonparallel to the central axis X1. According to the present modification, the timing at which the component force F2is generated becomes later than the configuration including the hook surface753according to the above embodiment (FIGS.1-11), and the connection between the hook70and the base20amay be stronger.

As described above, by changing the contact portion between the hook surface and the base surface, it is possible to variously adjust the amount and the timing for releasing the connection. The means for changing the contact portion is not limited to the means of changing the angle formed by the hook surface and the central axis X1as described above.

In the above described examples, the portion near the connection portion T in the plate-shaped portion76is regarded as the second deformation portion; however, the position of the second deformation portion is not limited thereto. In order to realize the above-mentioned operation for releasing the connection between the hook and the link, it only has to realize a positional relationship such that a moment larger than the moment generated in the second deformation portion by the traction force F is generated in the first deformation portion. In other words, as shown inFIG.14, it only has to determine the position of the second deformation portion such that the distance D1between the first deformation portion752and the line X2that is parallel to the central axis X1and passes through the contact portion P is longer than the distance D2between the line X2and the second deformation portion762. For example, the portion762A of the plate-shaped portion76located more distal than the connection site T may correspond to the second deformation portion. According to the present embodiment, since the plate-shaped portion extends substantially parallel to the central axis X1, any position of the plate-shaped portion may be considered as the second deformation portion.

The position of the first deformation portion in the central axis direction of the hook is not particularly limited as long as the first deformation portion is apart from the base line in the connection state. For example, the first deformation portion752may be provided at the distal end side of the hook more than the contact portion P.

In the modification shown inFIG.15, the first deformation portion752is provided at a position closer to the contact portion P in the direction in which the central axis X1extends than that according to the above embodiment (FIGS.1to11). In this manner, the moment applying to the claw portion75increases, and the connection is released smoothly. In order to enhance this effect, it is preferable to make the first deformation portion752to be located at the same position as the contact portion P in the direction in which the central axis X1extends.

Another exemplary embodiment of the present disclosure will be described with reference toFIGS.16to19. In the following description, the same components which are already described will be designated by the same reference numerals and redundant description will be omitted.

FIG.16shows the clip unit110according to the present embodiment. The clip unit110includes an arm portion120and a pressing tube30. The internal configuration of the pressing tube30is the same as that of the above embodiment (FIGS.1to15).

FIG.17shows a connection structure of the operation wire52and the arm part120, that is, the configuration of a link according to the present embodiment. The first arm121and the second arm122are individual members and joined by a joint portion123. The first arm121and the second arm122extend toward the rear side of the joint portion123. Examples of the method for forming the joint portion123include welding, soldering, bonding, brazing or the like.

Claw members175,177are attached to the proximal ends of the first arm121and the second arm122, respectively. The claw member175has a first deformation portion1752and a hook surface1753. The claw member177has a first deformation portion1772and a hook surface1773.

The claw members175,177may be formed of metal or the like, and may be formed of the same material as that of the first arm121and the second arm122. The claw members175,177may be fixed to the first arm121and the second arm122by welding, soldering, bonding, brazing, or the like.

A base153is fixed to the distal end of the operation wire52. The shape of the base153is not particularly limited as long as the base surface153athat is capable of being engaged with the hook surface1753and the hook surface1773is formed, and the base153may have the same shape as that of the base20a.

According to the present embodiment, the operating wire52and the clip unit110are connected by the claw members175,177sandwiching the base153.

In the state shown inFIG.17in which the operation wire52and the arm portion120are connected, the portions proximal than the joint portion123of the first arm121and the second arm122function as the plate-shaped portions124,125, and the regions near the joint portion123in the plate-shaped portions124,125function as the second deformation portions124a,125a, respectively.

The first deformation portion1752and the first deformation portion1772are at positions separated from the baseline B3of the first arm121and the baseline B4of the second arm122, respectively.

That is, according to the present embodiment, the clip unit has the hook170at the proximal end portion of the arm portion120, and the operation wire has the base.

According to the present embodiment, after the arm of the clip unit is locked, as shown inFIG.18, firstly, the rear portions of the claw members175,177provided in the clip unit rotate around the first deformation portions1752,1772as centers respectively. Subsequently, as shown inFIG.19, the plate-shaped portions124,125rotate around the second deformation portions124a,125aas centers, respectively, and the connection between the clip unit and the operation wire is released.

Similar to the above embodiment (FIGS.1to15), the clip unit and the ligation device according to the present embodiment may achieve both goals of indwelling the clip unit in the body while clamping the hard tissue and making the operation to be easy.

According to the present embodiment, since the hook170is provided in the clip unit, the hook170is indwelled inside the body together with the clip unit110. Accordingly, there is an advantage that the hook does not fatigue and fracture due to the repeatedly engagement and connections by applying the configuration to the reload type ligation device configured to attach a new clip to the applicator and then perform the indwelling operation again.

Another exemplary embodiment of the present disclosure will be described with reference toFIGS.20to27. In the following description, the same components as those already described will be designated by the same reference numerals and redundant description will be omitted.

A ligation device1C according to the present embodiment includes a clip unit (treatment portion)210and an applicator50configured to operate the clip unit210.

FIG.20is a view showing the clip unit210. The clip unit210includes the arm portion20and the pressing tube230.

The pressing tube230is the same as the pressing tube30of the above embodiment (FIGS.1to15) except for the shape of the proximal end opening230b. As shown inFIG.20, the proximal end opening230bis formed in a tapered shape whose inner diameter R1increases toward the outside (proximal end side) of the proximal end opening230b. The tapered portion of the proximal end opening230bis regarded as the engaged surface230s.

The shape of the hook70will be described in more detail.

The distal end portion75aof the claw portion75in the engagement arm73of the hook70is formed in a tapered shape whose dimension is decreased toward the distal end. As shown inFIG.20, the distal end portion75ais formed in a shape (for example, a tapered shape or an SR shape) whose thickness decreases toward the distal end.

The distal end portion75aof the claw75has a first engagement surface758and a second engagement surface759. As shown inFIG.20, the first engagement surface758and the second engagement surface759are arranged on both sides of the axis X2so as to sandwich the axis X2, wherein the axis X2passes through the distal end of the engagement arm73and is parallel to the central axis X1.

The first engagement surface758is arranged on the central axis X1side (inside) with respect to the axis X2. The normal line of the first engagement surface758is directed to the direction approaching the central axis line X1. The first engagement surface758may be a flat surface or a curved surface.

The second engagement surface759is arranged on the opposite side (outside) of the central axis X1with respect to the axis X2. The normal line of the second engagement surface759is directed to the direction separated from the central axis line X1. The second engagement surface759may be a flat surface or a curved surface.

Similar to the claw portion75, the claw portion77in the engaging arm73of the hook70is also formed in a tapered shape such that the dimension thereof decreases toward the distal end side. The distal end portion77aof the claw77has a first engagement surface778and a second engagement surface779, similar to the claw75.

FIG.21toFIG.24are cross-sectional views of a connecting portion showing a process of connecting the clip unit210and the applicator50. The operation of the ligation device1C having the above-described configuration will be described. The user uses a cartridge40to connect the clip unit210and the applicator50before inserting the ligation device1C into the endoscope.

As shown inFIG.21, the cartridge40is a substantially rectangular parallelepiped case configured to be capable of accommodating the clip unit210. The cartridge40has a cartridge body41and a fastener42.

The cartridge body41is formed in a bottomed cylindrical shape. As shown inFIG.21, the cartridge body41has an internal space S for accommodating the clip unit210in a state in which the arm portion20is accommodated in the pressing tube230and the clip unit210is unlocked. The cartridge body41has an opening41bcommunicating with the internal space S at one end portion41aat the central axis X3side of the internal space S.

In the internal space S of the cartridge body41, the length L1in the central axis X3direction is shorter than the length of the arm portion20accommodated in the pressing tube230in the longitudinal axis direction as shown inFIG.21. Therefore, at the time of accommodating the arm unit20in the state in which the arm portion20is accommodated in the pressing tube230, the base20ais arranged outside the cartridge body41. The base20ais arranged on the central axis line X3.

The fastener42is attached to the end portion41aof the cartridge body41so as to be slidable in a direction orthogonal to the central axis X3. The fasteners42are arranged on both sides of the center of the opening41bto sandwich the center of the opening41when viewed from the direction of the central axis X3. The fastener42may move to a first position to cover part of the opening41bby being slided in the direction approaching the central axis X3. Furthermore, the fastener42may move to a second position so as to not to cover the opening41bby being slided in the direction separating from the central axis X3.

The user moves the fastener42to the second position. The user accommodates the arm portion20in the pressing tube230. The user accommodates the clip unit210in the state in which the arm portion20is accommodated in the pressing tube230and the clip unit210is unlocked in the internal space S of the cartridge body41. Subsequently, the user moves the fastener42to the first position. As shown inFIG.21, the distal end of the arm portion20comes in contact with the cartridge body41. The proximal end of the pressing tube230comes in contact with the fastener42located at the first position. As a result, the arm portion20maintains the closed configuration in the state in which the arm portion20is not locked with respect to the pressing tube230.

As shown inFIG.22, the user moves the applicator50to approach the cartridge40accommodating the clip unit210. The user makes them to approach each other in a state in which the base20ais positioned on the central axis X1of the hook70. The base20aand the first engagement surface758engage with each other. Since the normal line of the first engagement surface758is directed to the direction approaching the central axis X1, the claw portion75moves in the direction away from the central axis X1. The base20aand the first engagement surface778engage with each other. Since the normal line of the first engagement surface778is directed in the direction approaching the central axis X1, the claw portion77moves in the direction away from the central axis X1.

As shown inFIG.23, the user further makes the applicator50to approach the cartridge40. The engaged surface230sof the pressing tube230and the second engagement surface759engage with each other. Since the normal line of the second engagement surface759is directed in the direction away from the central axis X1, the claw portion75moves in the direction approaching the central axis X1. The engaged surface230sof the pressing tube230and the second engagement surface779are engaged with each other. Since the normal line of the second engagement surface759is directed in the direction away from the central axis X1, the claw77moves in the direction approaching the central axis X1.

The normal line of the engaged surface230sis directed in the direction approaching the central axis X3. Therefore, as shown inFIG.23, the claw portion75and the claw portion77engaged with the engaged surface230smove in a direction approaching the central axis X3.

The user makes the applicator50to further approach the cartridge40. As a result, as shown inFIG.6, the locking surface (hook surface)753is locked to the front surface (base surface)754of the base20a. The locking surface (hook surface)773is locked to the front surface (base surface)754of the base20a. Due to the above-described operation, the clip unit210and the applicator50are connected.

Similar to the above embodiment, the clip unit210and the ligation device1C according to the present embodiment may achieve both goals of indwelling the clip unit210in the state of clamping the hard tissue and making the operation to be easy. According to the present embodiment, it becomes easy to load the clip unit210into the applicator50.

After the clip unit210and the applicator50are connected, the user moves the fastener42to the second position. As shown inFIG.24, the elastic restoring force of the coil spring31causes the arm portion20to be transitioned to the open configuration. The proximal end of the pressing tube230moves to the outside of the cartridge body41. The pressing tube230and the guide pipe55are connected. The connection between the clip unit210and the applicator50is maintained. Due to the above-described operation, the loading of the clip unit210to the applicator50is finished.

The user may separate the claw portion75and the claw portion77and move the claw portion75and the claw portion77to a position capable of clamping the base20aby making the clip unit210and the applicator50to approach each other in the direction of connecting the clip unit210and the applicator50. The user may further make the clip unit210and the applicator50to approach each other so as to make the claw portion75and the claw portion77to approach each other and move the claw portion75and the claw portion77to the position to be locked by the base20a. The user may only make the clip unit210and the applicator50to approach each other in a direction of connecting the clip unit210and the applicator50so as to advance and retract the claw portion75and the claw portion77in the direction orthogonal to the connecting direction and easily connect the clip unit210and the applicator50.

Modification 1

According to the present embodiment, an example in which the proximal end opening230bof the pressing tube230is formed in a tapered shape is described; however, the fastener42of the cartridge40may be formed in a tapered shape instead of the proximal end opening230b.

FIGS.25to27are cross-sectional views of a connection portion in a connection step using a cartridge40B including a fastener42B as a modification example of the fastener42.

The fastener42B is formed in a tapered shape at the central axis X3side such that a distance to the central axis X3increases toward the outside (proximal end side) of the cartridge40B. The portion of the fastener42B formed in the tapered shape is regarded as the engaged surface42s.

As shown inFIG.26, the user make the applicator50to further approach the cartridge40B. The engaged surface42sof the fastener42B and the second engagement surface759engage with each other, and the claw portion75moves in a direction approaching the central axis X1of the hook70. The engaged surface42sof the fastener42B and the second engagement surface779are engaged with each other, and the claw portion77moves in the direction approaching the central axis X1of the hook70.

The normal line of the engaged surface42sis directed in the direction approaching the central axis X3. Accordingly, as shown inFIG.26, the claw portion75and the claw portion77engaged with the engaged surface42smove in the direction approaching the central axis X3.

The user makes the applicator50to further approach the cartridge40B. The claw portion75and the claw portion77further approach each other. As a result, as shown inFIG.27, the claw portion75and the claw portion77are locked to the base20a. By the above-described operations, the clip unit10and the applicator50are connected.

Modification 2

According to the present embodiment, the fastener42is attached to the end portion41aof the cartridge body41; however, the fastener42may be arranged in the internal space S of the cartridge body41.

FIGS.28to32are cross-sectional views of a connection portion in a connecting step using a cartridge40C including a fastener42C as a modification of the fastener42. InFIGS.28to32, cross-sectional views of the connection portion by rotating at 90 degrees with respect to the central axis X3of the internal space S are also shown. The cartridge40C includes a cartridge body41C and a fastener42C.

As shown inFIG.28, the fasteners42C are arranged on both sides of the central axis line X3to sandwich the central axis line X3therebetween. The two fasteners42C are arranged in the internal space S with the pressing tube230being sandwiched from both sides. The two fasteners42C are arranged on both sides in the open-close direction P in which the arm portion20is opened and closed.

The fastener42C has a fastener body43, a first engagement protrusion44, a second engagement protrusion45, and a third engagement protrusion46. The fastener body43is formed in a plate shape extending in the direction of the central axis X3.

The first engagement protrusion44is a convex portion that protrudes outwardly in the open-close direction P at the distal end of the fastener body43. The distal end of the first engagement protrusion44is in contact with the inner circumferential surface41sof the cartridge body41C.

The second engagement protrusion45is a convex portion that protrudes outwardly in the open-close direction P at the proximal end of the fastener body43. The distal end of the second engagement protrusion45is in contact with the inner circumferential surface41sof the cartridge body41C.

The third engagement protrusion46is a convex portion that protrudes inwardly in the open-close direction P at the proximal end of the fastener body43. The distal end of the third engagement protrusion46engages with the proximal end of the pressing tube230. The third engagement protrusions46of the two fasteners42C are arranged at positions opposite to each other. The hook70may pass through the space between the third engagement protrusions46.

The third engagement protrusion46has a third engagement surface463formed in a tapered shape on the distal end side. The normal line of the third engagement surface463is directed in the direction approaching the central axis line X3. The third engagement protrusion46has a fourth engagement surface464formed in a tapered shape on the base end side. The normal line of the fourth engagement surface464is directed in the direction approaching the central axis line X3. The fourth engagement surface464guides the distal end of the hook70inserted into the cartridge40C in the direction approaching the central axis X3.

Similar to the cartridge body41, the cartridge body41C is formed in a bottomed cylindrical shape. As shown inFIG.28, the cartridge body41C has an internal space S capable of accommodating the clip unit210in the state in which the arm portion20is accommodated in the pressing tube230and the clip unit210is in the unlocked state. The cartridge body41C has an opening41bcommunicating with the internal space S at one end portion at the central axis X3side of the internal space S.

As shown inFIG.28, in the internal space S of the cartridge body41C, the length L2in the direction of the central axis X3is sufficiently longer than the length of the arm portion20accommodated in the pressing tube230in the longitudinal axis direction.

The cartridge body41C has an arm engagement recess47, a first engagement recess48, and a second engagement recess49in the internal space S. The arm engagement recess47is a concave portion into which the distal end side of the arm portion20is inserted. By inserting the arm portion20into the arm engaging recess47, it is difficult for the arm portion20to be unstable with respect to the central axis X3.

The first engagement recess48is a concave portion that is recessed outwardly in the open-close direction P on the inner circumferential surface41sof the cartridge body41C. The first engagement recesses48are formed on both sides of the central axis line X3to sandwich the central axis line X3therebetween.

The second engagement recess49is a concave portion that is recessed outwardly in the open-close direction P on the inner circumferential surface41sof the cartridge body41C. The second engagement recesses49are formed on both sides of the central axis line X3to sandwich the central axis line X3therebetween.

The first engagement recess48is located on the distal end side more than the second engagement recess49in the direction of the central axis X3. The distance between the first engagement recess48and the second engagement recess49in the central axis X3direction is substantially equal to the distance between the first engagement protrusion44and the second engagement protrusion45in the central axis X3direction.

In the fastener42C of the cartridge body41C, in the initial state, the third engagement protrusion46that engages with the pressing tube230is pressed toward the proximal end side by the elastic restoring force of the coil spring31. At this time, the first engagement protrusion44is positioned at the proximal end side more than the first engagement recess48. In the initial state, the second engagement protrusion45is positioned at the proximal end side more than the second engagement recess49.

The user makes the applicator50to approach the cartridge40C in which the clip unit210is accommodated. As shown inFIG.28, the hook70is inserted into the space between the two fasteners40C. The distal end of the guide pipe55comes in contact with the proximal end of the fastener42C.

As shown inFIG.29, the user makes the applicator50to further approach the cartridge40C. Similar to the present embodiment, the claw portion75and the claw portion77move in a direction away from the central axis X1. The distal end of the guide pipe55pushes the fastener42C toward the distal end side with respect to the cartridge body41C. The pressing tube230that engages with the third engagement protrusion46is pushed toward the distal end side with respect to the cartridge body41C against the elastic restoring force of the coil spring31.

As shown inFIG.30, the user makes the applicator50to further approach the cartridge40C, similar to the present embodiment, connects the clip unit210and the applicator50. The fastener42C that engages with the guide pipe55is further pushed toward the distal end side with respect to the cartridge body41C. As shown inFIG.30, when the clip unit210and the applicator50are arranged at a position where the clip unit210and the applicator50are connected to each other, the first engagement protrusion44is slightly located at the proximal end side than the first engagement recess48. The second engagement protrusion45is slightly located at the proximal end side than the second engagement recess49.

As shown inFIG.31, the user further pushes the applicator50. As a result, the first engagement protrusion44and the second engagement protrusion45do not come into contact with the inner circumferential surface41sof the cartridge body41C. The proximal end of the pressing tube230pushes the third engagement surface463of the third engagement protrusion46toward the proximal end side by the elastic restoring force of the coil spring31. Since the normal line of the third engagement surface463is directed in the direction approaching the central axis X3, the fastener42C moves in a direction separating from the central axis X3.

As shown inFIG.32, the fastener42C moves in a direction separating from the central axis X3, and the first engagement protrusion44and the first engagement recess48engage with each other. The second engagement protrusion45and the second engagement recess49are engaged with each other.

As shown inFIG.32, the pressing tube230that does not engage with the third engagement protrusion46moves to the proximal end side of the pressing tube230due to the elastic restoring force of the coil spring31. As a result, the clip unit210moves to the opening41bside.

In the cartridge40C, it is not necessary for the user to open and close the fastener42C. By making the clip unit210and the applicator50to approach each other only, the user may easily connect the clip unit210and the applicator50, and take out the clip unit210after the connection from the cartridge40C.

Although the respective embodiments and modifications of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and configurations in the respective embodiments and modifications within the scope not departing from the spirit of the present disclosure. It is possible to change the combination of elements, make various changes to each configuration element, or delete each configuration element.

In each of the above-described embodiments, an example in which the hook has a pair of engaging arms has been described; however, the aspect of the hook in the present disclosure is not limited thereto.

FIG.33shows an example of a hook including only one engagement arm. The hook270shown inFIG.33has one engagement arm271. Even with such a configuration, by appropriately determining the positional relationship among the first deformation portion271, the second deformable portion272, the contact portion P, and the base line B while appropriately setting the bending rigidity of the first deformation portion271and the second deformable portion272, it is possible to obtain the same effects as those according to the above-described embodiments.

In any of the above-described embodiments, the first deformation portion and the second deformation portion may be formed of different materials so as to achieve different bending rigidities of the first deformation portion and the second deformation portion. The first deformation portion and the second deformable portion may have a structure such as a hinge or the like with a rotating shaft.

The treatment portion according to the present disclosure is not limited to the above-mentioned clip unit. For example, similar to the medical device1A shown inFIG.34, the treatment portion90may have a snare loop91instead of the pair of arms.

In the treatment portion90, the configuration inside the pressing tube30is substantially the same as that of the clip unit10. A disk-shaped compression member92is attached between the locking portion23and the snare loop91. When the operating wire52is retracted, the snare loop91is drawn into the pressing tube30and contracts, while the coil spring31is compressed by the compression member92such that the binding operation by the snare loop91may be repeated. When the locking portion23is moved to the outside of the pressing tube30, the snare loop91is locked and in a small size. When the connection of the link80is released, the treatment portion90may be separated from the applicator50.

According to the present modification, the loop shape of the snare loop91is not particularly limited.

Although the respective embodiments and modifications of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and configurations in the respective embodiments and modifications within the scope not departing from the spirit of the present disclosure. It is possible to change the combination of elements, make various changes to each configuration element, or delete each configuration element. For example, the configuration according to any one of above-described embodiments and modifications of the present disclosure may be appropriately combined with each modification of the operation section. The present disclosure is not limited by the above description, but only by the appended claims.