Cover member and treatment instrument

A cover member includes: a sheath that is formed in a cylindrical shape for receiving a shaft; and a tubular portion that is attached to a distal end of the sheath. The tubular portion being formed such that an outer dimension of a distal end portion of the tubular portion in a first direction is smaller than an outer dimension of a proximal end portion of the tubular portion in the first direction and/or an outer dimension of the distal end portion in a second direction is smaller than an outer dimension of the proximal end portion in the second direction.

BACKGROUND

1. Technical Field

The present disclosure relates to a cover member and a treatment instrument.

2. Related Art

In the related art, a treatment instrument that applies an energy to a site subject to treatment in a living tissue (hereinafter, target site), and thereby treats the target site has been known.

For example, the known treatment instrument can be an ultrasound treatment instrument, and can have a vibration transmission member that transmits ultrasonic vibration from a proximal end to a distal end. This vibration transmission member is inserted in a cylindrical sheath with its distal end exposed to the outside. To a distal end of the sheath, a cap to prevent a contact with the vibration transmission member is attached.

SUMMARY

In some embodiments, provided is a cover member that extends in a longitudinal axis direction from a distal end toward a proximal end of the cover member and can receive a shaft provided with an end effector for treating a living tissue at a distal end of the shaft. The cover member includes: sheath that is formed in a cylindrical shape for receiving the shaft; and a tubular portion that is attached to a distal end of the sheath. The tubular portion is formed such that an outer dimension of a distal end portion of the tubular portion in a first direction perpendicular to the longitudinal axis direction is smaller than an outer dimension of a proximal end portion of the tubular portion in the first direction and/or an outer dimension of the distal end portion in the second direction perpendicular to the first direction and the longitudinal axis direction, is smaller than an outer dimension of the proximal end portion in the second direction.

In some embodiments, a treatment instrument includes: a shaft including an end effector for treating a living tissue at a distal end of the shaft; and a cover member including a tubular portion that extends along a longitudinal axis direction from a distal end portion toward a proximal end portion of the tubular portion. The shaft can be inserted into an inside of the tubular portion in a state in which the end effector protrudes out from a distal end of the tubular portion. The tubular portion is formed such that an outer dimension of the distal end portion in a first direction perpendicular to the longitudinal axis direction is smaller than an outer dimension of the proximal end portion in the first direction and/or an outer dimension of the distal end portion in a second direction, perpendicular to the first direction and the longitudinal axis direction, is smaller than an outer dimension of the proximal end portion in the second direction.

DETAILED DESCRIPTION

Hereinafter, forms to implement the disclosure (hereinafter, embodiments) will be explained with reference to the drawings. Embodiments explained below are not intended to limit the disclosure. Furthermore, in description of the drawings, like reference symbols are assigned to like parts.

Schematic Configuration of Treatment System

FIG.1is a diagram illustrating a treatment system1according to an exemplary embodiment.

The treatment system1applies a treatment energy to a site to be treated in a living tissue (hereinafter, treatment site), and thereby, treats the treatment site. In the present embodiment, as the treatment energy, an ultrasonic energy and a high frequency energy are used. Moreover, examples of the treatment include coagulation and incision of a target site. This treatment system1includes, as illustrated inFIG.1, a treatment instrument and a control device

Configuration of Treatment Instrument

The treatment instrument2is an ultrasound treatment instrument that applies least an ultrasonic energy to a target site, and that thereby treats the treatment site. This treatment instrument2includes a treatment-instrument main unit4and an ultrasound transducer5.

The treatment-instrument main unit4is a component applies a treatment energy to a target site. This treatment-instrument main unit4includes, as illustrated inFIG.1, a housing6, a rotating knob7, a sheath8(refer toFIG.2), a holding portion9(refer toFIG.2FIG.3), a vibration transmission member10, and a cap11.

FIG.2andFIG.3are diagrams illustrating an inner part of the housing.

InFIG.2andFIG.3explained below, XYZ coordinate axes inFIG.1are used. The X axis is an axis parallel to a center axis Ax of the sheath8. The center axis Ax corresponds to a longitudinal axis. Moreover, in the following, one side along the center axis Ax is denoted as a distal end side Ar1, and the other side is denoted as a proximal end side Ar2.

FIG.2is a cross-section of the treatment-instrument main unit4cut along an XZ plane including the center axis Ax. Moreover,FIG.3is a cross-section of the treatment instrument main unit4cut along an XY plane including the center axis Ax.

The housing6has a substantially cylindrical shape coaxial with the center axis Ax. The housing6supports the entire treatment-instrument main unit4In the present embodiment, the housing6is constituted of a first and a second housings61,62as illustrated inFIG.1toFIG.3.

The first housing61includes, as illustrated inFIG.1toFIG.3, a proximal-end-side housing portion611, a distal-end-side housing portion612(FIG.1,FIG.3).

The proximal end side housing portion611is positioned on the proximal end side Ar2relative to the distal-end-side housing portion612, and has a cylindrical shape coaxial with the center axis Ax. In the proximal-end-side housing portion611, the ultrasound transducer5is inserted.

The distal-end-side housing portion612is a portion that is formed integrally with an end portion of the proximal-end-side housing portion611on the distal end side Ar1, and has a substantially semicircular shape on a cross-section cut along a plane perpendicular to the center axis Ax.

The second housing62has a substantially semicircular shape on a cross-section cut along a plane perpendicular to the center axis Ax. At an edge of this second housing62plural bosses621that respectively protrude along the Y axis are arranged as illustrated inFIG.2. The second housing62is attached tr the distal-end-side housing portion612by press-fitting the bosses621into plural concave portions (not illustrated) arranged at the edge the distal-end-side housing portion612. That proximal-end-side housing portion611in which the ultrasound transducer5is inserted thereinside, bosses or e like are not arranged.

Moreover, in the housing6, a switch63that is arranged exposed to the outside, and that accepts a treatment start operation or the like performed by an operator is provided as illustrated inFIG.1orFIG.2. The switch63outputs an operation signal according to the treatment start operation to the control device3through an electric cable C (FIG.1) that electrically connects the treatment instrument2and the control device3.

The rotating knob7has a substantially cylindrical shape coaxial with the center axis Ax and is arranged in the housing6on the distal end side Ar1as illustrated inFIG.1toFIG.3. This rotating knob7accepts a rotation operation performed by the operator. The rotation operation is an operation to rotate the vibration transmission member10about the center axis Ax. The rotating knob7and the vibration transmission member10rotate about the center axis Ax by the rotation operation.

The sheath8is a cylindrical pipe made from a material, such as metal. To the sheath8, the vibration transmission member10is inserted.

A structure of an end portion of the sheath8on the end side Ar1will be described later in “About Distal End Portion of Treatment-Instrument Main Unit”.

The holding portion9is made from, for example, resin material having electrical insulation, and has a substantially cylindrical shape coaxial with the center axis Ax. This holding portion9is housed rotatably about the center axis Ax in the housing6in such a manner that an end portion on the distal end side Ar1protrudes out from the housing6as illustrated inFIG.2orFIG.3. The holding portion9holds the vibration transmission member10in a state in which the vibration transmission member10is inserted thereinside. Furthermore, the holding portion9holds the sheath8in such a manner that an end portion of the sheath8on the proximal end side Ar2is inserted therein from the distal end side Ar1.

On an outer peripheral surface of the holding portion9, as illustrated inFIG.3, a flange portion91jutting out toward the outside is arranged on the distal end side Ar1. Moreover, on an inner peripheral surface of the rotating knob7, a base portion71that protrudes toward the center axis Ax and a claw portion72that protrudes from the base portion71toward the proximal end side Ar2, and that is capable of elastic deformation in a direction of diameter of the rotating knob7about the base portion71as the base point are arranged on the distal end side Ar1as illustrated nFIG.3. The rotating knob7is attached to the holding portion9as the end portion of the holding portion9on the distal end side Ar1is inserted from the proximal end side Ar2, and the claw portion72engages with the flange portion91. That is, the rotating knob7is attached to the holding portion9by the snap-fit mechanism. Therefore, it becomes possible to arrange the switch63close to the rotating knob7compared to a structure in which the rotating knob7is attached to the housing6.

According to a rotation operation to the rotating knob7by an operator, the holding portion9rotates with the rotating knob7about the center axis Ax. Moreover, the vibration transmission member10and the sheath8rotate with the holding portion9about the center axis Ax because ey are attached to the holding portion9.

On the outer peripheral surface of the holding portion9, an O-ring92(FIG.3) having elasticity attached to prevent unintended rotation of the rotation knob7, the holding portion9, the vibration transmission member10, and the sheath8about the center axis Ax. The O-ring92abuts on an inner peripheral surface of the housing6. That is, by using friction between the O-ring92and the housing6, unintended rotation of the rotating knob7and the like about the center axis Ax is prevented.

The cap11is made from a resin material, such as polyetheretherketone (PEEK) having electric insulation, and has a substantially cylindrical shape surrounding the center axis Ax. The cap11is attached to the distal end of the sheath8.

The sheath8and the cap11correspond to a cover member. Moreover, the cap11corresponds to a tubular portion.

Details of the shape of the cap11will be explained in “About Distal End Portion of Treatment Instrument” described later.

The vibration transmission member10corresponds to a shaft. This vibration transmission member10is made from an electrically conductive material, and has a long shape extending along the center axis Ax. Moreover, the vibration transmission member10is inserted in the sheath8, the holding portion9, and the cap11in state in which an end portion101(hereinafter, denoted as end effector101) on the distal end side Ar1is exposed to the outside, and is fixed to the holding portion9. Furthermore, the end portion of the vibration transmission member10on the proximal end side Ar2is connected to a bolt-clamped Langevin transducer (BLT) constituting the ultrasound transducer5. The vibration transmission member10transmits an ultrasonic vibrations generated by the ELT from the end portion on the proximal end side Ar2to the end portion on the distal end side Ar1. In the present embodiment, the ultrasonic vibration is a vertical vibration vibrating in a direction along the center axis Ax.

Details of the shape of the end effector101will be explained in “About Distal End Portion of Treatment Instrument” described later.

The ultrasound transducer5is inserted into the proximal-end-side housing portion611from the proximal end side Ar2of the proximal-end-side housing portion611, and is detachably connected to the proximal-end-side housing portion611. This ultrasound transducer5has a BLT that generates an ultrasonic vibration according to a supply of a driving signal, which is an alternating current, although specific illustration thereof is omitted.

Configuration of Control Device

To the control device3, the treatment instrument2is detachably connected by the electric cable C. The control device3overall controls operation of the treatment instrument2as described below, according to an operation signal (instrument start operation) input from the switch63through the electric cable C.

The control device3outputs a driving signal to the BLT constituting the ultrasound transducer5through the electric cable C, Thus, the BLT generates an ultrasonic vibration (vertical vibration). Moreover, the end effector101vibrates at a desired amplitude by the vertical vibration. To the target site in contact with the end effector101, the ultrasonic vibration is applied from the end effector101. In other words, an ultrasonic energy is applied to the target site from the end effector101.

Furthermore, the control device3is connected to a return electrode (not illustrated) by an electric cable (not illustrated). The return electrode is attached to a surface of a subject. The control device3outputs a high frequency signal, which is a high frequency electric power, to a portion between the vibration transmission member10and the return electrode through the electric cable C. Thus, a high frequency electric current flows through the target site positioned between the end effector101and the return electrode. In other words, a high frequency energy is applied to the target site from the end effector101,

About Distal End Portion of Treatment Instrument

Next, a distal end portion of the treatment-instrument main unit4will be explained.

FIG.4andFIG.5are diagrams illustrating the distal end portion of the treatment-instrument main unit Specifically,FIG.4illustrates an external view of the distal end portion of the treatment-instrument main unit4. InFIG.4, for convenience of explanation, a tube TU is illustrated with an alternate long and short dash line.FIG.5illustrates a cross-section taken along a line v-v inFIG.4.

InFIG.4andFIG.5, two directions perpendicular to the center axis Ax are denoted as first direction Ar3and second direction Ar4. The first direction Ar3is a vertical direction inFIG.4, The second direction Ar4is a vertical direction inFIG.5.

First, the shape of the end effector101will be explained.

The end effector101includes, as illustrated inFIG.4, a pillar portion1011that extends along the center axis Ax, and a hook portion1012that protrudes along the first direction Ar3(downward inFIG.4) substantially perpendicular to the pillar portion1011from an end portion of the pillar portion1011on the distal end side Ar1.

That is, an outer dimension of the hook portion1012in the first direction Ar3is larger than the outer dimension of the pillar portion1011in the first direction Ar3. Moreover, the outer dimension of the hook portion1012in the second direction Ar4is smaller than the outer dimension in the first direction Ar3.

Next, a structure of the cap11will be explained.

The cap11includes an engaging portion111, connecting portion112, and an exposed portion113as illustrated inFIG.4toFIG.7.

The engaging portion111has a cylindrical s ape coaxial with center axis Ax. In the present embodiment, the outer dimension of the engaging portion111is a little smaller than the inner dimension of the sheath8. Moreover, respective inner dimensions of the engaging portion111, the connecting portion112, and the exposed portion113are smaller than the outer dimension of the hook portion1012in the first direction Ar3.

In this engaging portion111, a pair of notch portions1111that respectively pierce through from the outer peripheral surface to the inner peripheral surface are arranged as illustrated inFIG.6orFIG.7. These pair of notch portions1111respectively have a U-shape, Inside the U-shape of the notch portion1111, a claw portion1112that extends from the distal end side Ar1to the proximal end side Ar2, and that is capable of elastic deformation in a direction of diameter of the engaging portion111about a based portion of the distal end side Ar1as a base point is formed. The pair of the notch portions1111(pair of the claw portions1112) are arranged at rotationally symmetric positions by 180° about the center axis Ax.

The connecting portion112is a portion connecting an end portion in the engaging portion111on the distal end side Ar1and an end portion in the exposed portion113on the proximal end side Ar2, and as a substantially cylindrical shape surrounding the center axis Ax. In the connecting portion112, an end portion on the proximal end side Ar2connected to the engaging portion111has an outer diameter larger than the engaging portion111. That is, on an outer peripheral surface of the cap11, a first step portion114(FIG.4toFIG.7) is arranged between the connecting portion112and the engaging portion111.

On the outer peripheral surface of the engaging portion111, a positioning portion1113(FIG.4, FIG.FIG.7) that juts out and extends from the first step portion114toward the proximal end side Ar2is arranged.

Moreover, the outer peripheral surface of the connecting portion.112is formed by a first slant surface1121and a first distal-end outer-peripheral surface1122continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.4toFIG.7.

The first slant surface1121is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the first step portion114.

The first distal-end outer-peripheral surface1122is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the first slant surface1121.

The exposed portion113has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion112on the distal end side Ar1. In this exposed portion113, an end portion on the proximal end side Ar2connected to the connecting portion112has a larger outer diameter dimension than the first distal-end outer-peripheral surface1122. That is, on the outer peripheral surface of the cap11, a second step portion115(FIG.4toFIG.7) is arranged between the exposed portion113and the connecting portion112. The outer peripheral surface of the exposed portion113has a protruded surface1131that juts out toward the outside in the direction of diameter of the exposed portion113. This protruded surface1131is a surface abutting on the second step portion115and corresponds to a protruded portion.

Moreover, the outer peripheral surface of the exposed portion113is formed, as illustrated inFIG.4toFIG.7, by the protruded surface1131, a second slant surface1132, and a second distal-end outer-peripheral surface1133arranged continuously from the proximal end side Ar2toward the distal end side Ar1.

The protruded surface1131is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the second step portion115.

The second slant surface1132is a surface in which a diameter dimension decreases toward the distal end side from a position abutting on the protruded surface1131.

The second distal-end outer-peripheral surface1133a surface that substantially linearly extends toward the distal end side Ar1along the center axis from a position abutting on the second slant surface1132.

An outer diameter dimension of a distal end portion110(FIG.4toFIG.7) having the second distal-end outer-peripheral surface1133is smaller than an outer diameter dimension of the engaging portion111corresponding to a proximal end portion. Moreover, the outer diameter dimension of the distal end portion110is smaller than an outer dimension of the hook portion1012in the first direction Ar3as illustrated inFIG.4. The distal end portion110is made thin, and has a function of providing a field of view for an operator that uses the treatment-instrument main unit4, or the like.

In the cap11explained above, a first slit116(FIG.6) and a second slit117(FIG.7) are arranged on one end side (lower side inFIG.6, FIG. in the first direction Ar3.

The first slit116is a slit that is linearly cut along the center axis from a distal end of the cap11to a portion before the protruded surface1131.

The second slit117is a slit that is linearly cut along the center axis Ax from a proximal end of the cap11to a portion before the first distal-end outer-peripheral surface1122.

Width dimensions of the first and the second slits116and117are a little larger than the outer dimension of the hook portion1012in the second direction Ar4.

Finally, a structure of an end portion of the sheath8on the distal end side Ar1will be explained.

In the end portion of the sheath8on the distal end side Ar1, a pair of engagement opening portions811(FIG.4,FIG.5) that respectively pierce through from an outer peripheral surface to an inner peripheral surface, and with which the pair of claw portions1112are respectively engaged are arranged.

Furthermore, in the sheath8, a positioning notch portion812(FIG.4) that is cut toward the proximal end side Art from the distal end, and in which the positioning portion1113is inserted is arranged.

On an outer peripheral surface of the sheath8and the like, the tube TU (FIG.4,FIG.5) is attached.

This tube TU is a heat shrinkable tube made from a resin material having electric insulation.

Manufacturing Method of Treatment Instrument.

Next, a manufacturing method of the treatment instrument2will be explained.

FIG.8is a flowchart illustrating the manufacturing method of the treatment instrument2.FIG.9toFIG.16are diagrams explaining the manufacturing method of the treatment instrument2.FIG.12toFIG.16are cross-sections of the vibration transmission member10and the like cut along a plane including a point of the hook portion1012(end portion on a lower side inFIG.12toFIG.16) and the center axis Ax.

First, an operator inserts an end portion of the sheath8on the proximal end side Ar2into the inside of the holding portion9from the distal end side Ar1of the holding portion9as illustrated inFIG.9(step S1). Thus, the sheath6is attached to the holding portion9as illustrated inFIG.10.

After step S1, the operator inserts the end portion of the vibration transmission member10on the distal end side Ar1into the inside of the holding portion9and the sheath8from the proximal end side Art of the holding portion9as illustrated inFIG.11(step S2). Thus, the vibration transmission member10is attached to the holding portion9in a state in which the end effector101protrudes out from the distal end side Ar1of the sheath8.

After step S2, the operator attaches e cap11to the sheath8as described below (step S3).

First, the operator positions the first and the second slits116and117on a lower side inFIG.12(side of the point of the hook1012), inclines the cap11in such a posture that the distal end side Ar1is positioned on a lower side inFIG.12relative to the proximal end side Ar2. The operator then inserts the hook portion1012into the inside of the cap11from the second slit117of the cap11in such a posture.

Next, the operator rotates the cap11as illustrated inFIG.13,FIG.14, andFIG.15, and inserts the pillar portion1011into inside of the cap11from the second slit117. Thus, the point in the hook portion1012protrudes out to the outside of the cap11from the first slit116. That is, the first and the second slits116,117are slits provided to prevent interference with the end effector101.

Next, the operator moves the cap11toward the proximal end side Ar2as illustrated inFIG.16, and inserts the engaging portion111into the inside of the sheath8while inserting the positioning portion1113to the positioning notch portion812. Thus, the hook portion1012protrudes toward the distal end side Ar1from, the cap11. The cap11is attached to the sheath8as the claw portion1112is engaged with the engagement opening portion811. That is, the cap11is attached to the sheath8by a snap-fit mechanism.

After step S3, the operator inserts the end effector101, the cap11, the sheath8, and the end portion of the holding portion9on the distal end side Ar1into the inside of the tube TU from the proximal end side Ar2of the tube TU. The operator then applies heat to the tube TU to make the tube TU shrink in the direction of diameter dimension of the tube TU (step S4).

A distal end of the tube TU is positioned between the protruded surface1131and the first slant surface1121, that is, on the first distal-end outer-peripheral surface1122as illustrated inFIG.4orFIG.5. In the present embodiment, the diameter dimension in the protruded surface1131is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.4. Moreover, the outer diameter dimension at the protruded surface1131may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

Moreover, the proximal end of the tube TU is positioned on an outer peripheral surface of the end portion of the holding portion9on the distal end side Ar1as illustrated in an enlarged view ofFIG.2, That is, gap between th sheath8and the holding portion9is protected by the tube TU.

As described above, the tube TU is arranged at a position to cover both the outer peripheral surface of the sheath8and the outer peripheral surface of the cap11straddling a boundary between the sheath8and the cap11. Moreover, in the sheath8and the cap11, the engaging portion111and a part of the first slant surface1121are an overlap area overlapping in the radial direction. The tube TU covers the overlap area.

According to the present embodiment explained above, following effects are obtained.

In the present embodiment, the cap11has the distal end portion110, an outer diameter dimension of which is smaller than an outer diameter dimension of the engaging portion111. Moreover, the outer diameter dimension at the distal end portion110is smaller than the outer dimension of the hook portion1012in the first direction Ar1. Therefore, according to the present embodiment, the distal end portion110can be made thin, and a field of view for an operator that uses the treatment-instrument main unit4or the like can be acquired.

Furthermore, in the cap11, the first and the second slits116,117are provided. Therefore, while avoiding interference with the end effector101, the cap11can receive the end effector101inserted thereinside.

Particularly, the first and the second slits116,117are not slits piercing through from the distal end to the proximal end of the cap11. Therefore, it is possible to prevent reduction of strength of the cap11more than necessary. Moreover, because it is possible to prevent the cap11from being deformed more than necessary, dropping off of the cap11due to deformation can be prevented.

Furthermore, the treatment instrument2includes the tube TU that is arranged at a position enabling to cover both the outer peripheral surface of the sheath8and the outer peripheral surface of the cap11straddling the boundary between the sheath8and the cap11, and that shrinks in the direction of diameter perpendicular to the center axis Ax. That is, the cap11is in a state of being fastened by the shrinking force of the tube TU. Accordingly, it is possible to prevent dropping off of the cap11from the sheath8.

Moreover, the cap is attached to the sheath8by the snap-fit mechanism by the engaging portion111. Therefore, the cap11can be attached to the sheath S easily. The tube TU covers the overlap area, which is a portion corresponding to the engaging portion111. Therefore, the overlap area is protected by the tube TU, and even when an external force is applied to the overlap area, an engagement state of the cap11with respect to the sheath8can be favorably maintained. That is, dropping off of the cap11from the sheath8can be effectively prevented.

Furthermore, the tube TU covers the first slant surface1121. Therefore, it forms a structure that the first slant surface1121is caught by the tube TU, and dropping off of the cap11from the sheath8can be effectively prevented.

Moreover, the diameter dimension at the protruded surface1131is substantially the same as the outer diameter dimension of the tube TU at the distal end. Therefore, a structure in which the outer peripheral surface of the cap11and the outer peripheral surface of the tube TU are connected on an identical plane without a gap. That is, dropping off of the cap11from the sheath8caused because something is caught by the gap does not occur.

Furthermore, the cap11is made from a resin material having electric insulation. Therefore, it is not necessary to cover the cap11up to the distal end with the tube TU. That is, because the distal end portion is not covered with the tube TU, the distal end portion can be race thin, and a field of view for an operator that uses the treatment-instrument main unit4or the like can be provided.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiment described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above in a structure of the distal end portion (structures of the sheath8and the cap11) of the treatment-instrument main unit4.

In the following, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2A. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4A. Furthermore, the sheath8according to the present embodiment will be denoted as sheath8A. Moreover, the cap11according to the present embodiment will be denoted as cap11A.

The sheath8A and the cap11A correspond to a cover member. Moreover, the cap11A corresponds to a tubular portion.

FIG.17toFIG.19are diagrams illustrating a distal end portion of the treatment-instrument main unit4A according to the present embodiment. Specifically,FIG.17andFIG.18are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4A. WhileFIG.17illustrates a state in which the tube TU is removed,FIG.18illustrates a state in which the tube TU is attached.FIG.19is a cross-section of the distal end portion of the treatment-instrument main unit4A cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11A is made from a resin material, such as PEEK having electric insulation. This cap11A includes an engaging portion121and an exposed portion122as illustrated inFIG.17toFIG.19.

The engaging portion121includes an engaging-portion main unit1211and a pair of arm portions1212as illustrated inFIG.17orFIG.19.

The engaging-portion main unit1211has a cylindrical shape coaxial with the center axis Ax. In the present embodiment, an inner diameter dimension of the engaging-portion main unit1211is a little larger than an outer diameter dimension of the sheath8A.

The pair of the arm portions1212oppose to each other from a proximal end of the engaging-portion main unit1211and protrude toward the proximal end side Ar2, and is capable of elastic deformation in a direction of becoming close to and apart from each other, from a proximal end on the distal end side Ar1as a base point. In these pair of the arm portions1212, convex portions1213(FIG.17) are arranged respectively on surfaces opposing to each other on the proximal end side Ar2.

The exposed portion122has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the engaging-portion main unit1211on the distal end side. In the present embodiment, an inner diameter dimension at the exposed portion122is smaller than the outer dimension of the hook portion1012in the first direction Ar3. In this exposed portion122, an end portion on the proximal end side Ar2connected to the engaging-portion main unit1211has a larger outer diameter dimension than the engaging-portion main unit1211. That is, on the outer peripheral surface of the cap11A, a step portion123(FIG.17toFIG.19) is arranged between the exposed portion122and the engaging-portion main unit1211. Hereinafter, for convenience of explanation, a surface abutting on the step portion123on the outer peripheral surface of the exposed portion122will be denoted as protruded surface1221.

Moreover, an outer peripheral surface of the exposed portion122is formed by the protruded surface1221, a slant surface1222, and a distal-end outer-peripheral surface1223continuously arranged from the proximal end side Art toward the distal end side Ar1as illustrated inFIG.17toFIG.19.

The protruded surface1221is a surface that linearly extends from a position abutting on the step portion123toward the distal end side Ar1along the center axis Ax.

The slant surface1222is a surface in which a diameter dimension gradually decreases from the position abutting on the protruded surface1221toward the distal end side Ar1.

The distal-end outer-peripheral surface1223is a surface that linearly extends from a position abutting on the slant surface1222toward the distal end side Ar1along the center axis Ax.

An outer diameter dimension at a distal end portion120having the distal-end outer-peripheral surface1223(FIG.17toFIG.19) is smaller than an outer diameter dimension at the engaging-portion main unit1211corresponding to a proximal end portion. Moreover, an outer diameter dimension at the distal end portion120is smaller than an outer dimension of the hook portion1012in the first direction Ar3. The distal end portion120is made thin, and thereby has a function of providing a field of view for an operator that uses the treatment-instrument main unit4A or the like.

In the cap11A explained above, a slit124(FIG.17,FIG.18) that is cut linearly along the center axis Ax from a distal end to a proximal end is arranged on an end side in the first direction Ar3. This slit124corresponds to a first slit.

A width dimension of this slit124is a little larger than the outer dimension of the hook portion1012in the second direction Ar4.

At an end portion of the sheath8on the distal end side Ar1, as illustrated inFIG.17, a pair of flat portions821are arranged by processing a side wall portion.

The pair of the flat portions821are flat planar portions that respectively extend toward the proximal end side Ar2from the distal end in the sheath8A, and that are parallel to each other. A separation distance between outer surfaces of these flat portions821is substantially e same as a separation distance between surfaces opposing to each other in the pair of the arm portions1212. In these pair of the flat portions821, a pair of engagement opening portions822(FIG.17) that pierce through from a front surface to a rear surface, and with which the pair of convex portions1213are engaged are arranged, respectively.

In a manufacturing method of the treatment instrument2A according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101into the inside of e cap11A from the proximal end side Ar2of the cap11A in such a state that the point of the hook portion1012fits in the slit124. The operator makes the hook portion1012protrudes out from the distal end side Ar1of the cap11A. Moreover, the operator moves the cap11A to the proximal end side Ar2, and slides the pair of the convex portions1213on the outer surfaces of the pair of the flat portions821, to insert the end portion of the sheath8A on the distal end side Ar1into the inside of the engaging-portion main unit1211. The cap11A is attached to the sheath8A as the convex portion1213engages with the engagement opening portions822. That is, the cap11A is attached to the sheath8A by snap-fit mechanism.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned on the outer peripheral surface of the engaging-portion main unit1211as illustrated inFIG.19. In the present embodiment, a diameter dimension at the protruded surface1221is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.19. Moreover, the diameter dimension at the protruded surface1221may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8A and the outer peripheral surface of the cap11A, straddling a boundary between the sheath8A and the cap11A. Moreover, in the sheath8A and the cap11A, a portion corresponding to the engaging portion121is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4A according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2B. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4B. Furthermore, the sheath8according to the present embodiment will be denoted as sheath8B. Moreover, the cap11according to the present embodiment will be denoted as cap11B.

The sheath8B and the cap11B correspond to the cover member. Moreover, the cap11B corresponds to the tubular portion.

FIG.20toFIG.22are diagrams illustrating a distal end portion of the treatment-instrument main unit.4B according to the present embodiment. Specifically,FIG.20andFIG.21are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4B. WhileFIG.20illustrates a state in which the tube TU is removed,FIG.21illustrates a state in which the tube TU is attached.FIG.22is a cross-section of the distal end portion of the treatment-instrument main unit4B cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11B is made from a resin material, such ac polytetrafluoroethylene (PTFE) or tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) having electric insulation. This cap11B includes an engaging portion131and an exposed portion132as illustrated inFIG.20toFIG.22.

The engaging portion131has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion131is a little larger than an outer diameter dimension of the end portion of the sheath BB on the distal end side Ar1. Moreover, an inner diameter dimension of the engaging portion131is a little larger than an outer dimension of the hook portion1012in the first direction Ar3.

In this engaging portion131, as illustrated inFIG.20, a pair of notch portions1311that pierce through from an outer peripheral surface to an inner peripheral surface are arranged. These pair of the notch portions1311respectively have a U-shape. Inside the U-shape of the notch portion1311, a claw portion1312that extends from the proximal end side Ar2to the distal end side Ar1, and that is capable of elastic deformation in a direction of diameter of the engaging portion131from a base portion on the proximal end side Ar2as a base point is formed. The pair of the notch portions1311(pair of the claw portions1312) are arrange at rotationally symmetric positions by 180° about the center axis Ax.

The exposed position132has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at a distal end of the engaging portion131on the distal end side Ar1. In this exposed portion132, an end portion on the proximal end side Ar2connected to the engaging portion131has a larger outer diameter dimension than the engaging portion131. That is, on an outer peripheral surface of the cap11B, a step portion133(FIG.20toFIG.22) is arranged between the exposed portion132and the engaging portion131. Hereinafter, for convenience of explanation, a surface abutting on the step portion133on the outer peripheral surface of the exposed portion132will be denoted as protruded surface1321.

Moreover, the outer peripheral surface of the exposed portion132is formed by the protruded surface1321, a slant surface1322, and a distal-end outer-peripheral surface1323continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.20toFIG.22.

The protruded surface1321is a surface that linearly extends from a position abutting on the step portion133toward the distal end side Ar1along the center axis Ax.

The slant surface1322is a surface in which a diameter dimension gradually decreases from the position abutting on the protruded surface1221toward the distal end side Ar1.

The distal-end outer-peripheral surface1323is a surface linearly extends from a position abutting on the slant surface1222toward the distal end side Ar1along the center axis Ax.

In the present embodiment, an inner diameter dimension of the exposed portion132at the end portion on the distal end side Ar1is smaller than the outer dimension of the hook portion1012in the first direction Ar3.

An outer diameter dimension of a distal end portion130(FIG.20toFIG.22) having the distal-end outer-peripheral surface1323is smaller than an outer diameter dimension of the engaging portion131corresponding to a proximal end portion. Moreover, the outer diameter dimension of the distal end portion130is smaller than the outer dimension of the hook portion1012in the first direction Ar3. The distal end portion130is made thin, and thereby acquires a function of “providing” a field of view for an operator that uses the treatment-instrument main unit4B or the like.

In the cap11B explained above, a slit134(FIG.20toFIG.22) that is linearly cut along the center axis from the proximal end of the exposed portion132toward the distal end side Ar1is arranged on one end side in the first direction Ar3. This slit134corresponds to a first slit.

A width dimension of this slit134is a little larger an the outer dimension of the hook portion1012in the second direction Ar4.

An outer diameter dimension and an inner diameter dimension of the end portion of the sheath8B on the distal end side Ar1gradually decrease toward the distal end side Ar1as illustrated inFIG.20orFIG.22. In the present embodiment, the inner diameter dimension of the end portion on the distal end side Ar1is smaller than the outer dimension of the hook portion1012in the first direction Ar3. In the end portion on the distal end side Ar1, a slit831(FIG.20) that pierces through from the outer peripheral surface to the inner peripheral surface, and that extends from the distal end of the sheath8B toward the proximal end side Ar2to avoid interference with the hook portion1012when performing step S2is arranged. Moreover, in the end portion on the distal end side Ar1, a pair of engagement opening portions (not illustrated) that pierce through from the outer peripheral surface to the inner peripheral surface, and with which a pair of claw portions1312are engaged are arranged.

In a manufacturing method of the treatment instrument2B according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101into the inside of the cap11B from the proximal end side Ar2of the cap11B. Because the cap11B is made from a relatively flexible material, such as PTFE or PFA, the operator makes the hook portion1012protrudes out from the distal end side Ar1of the cap11B by moving the cap11B toward the proximal end side Ar2while deforming the cap11B. Moreover, the operator inserts the end portion of the sheath8B on the distal end side Ar1into the inside of the engaging portion131. The cap11B is attached to the sheath8B as the claw portions1312engage with the engagement opening portions (not illustrated) arranged in the sheath8B. That is, the cap11B is attached to the sheath8B by the snap-fit mechanism.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned on the outer peripheral surface of the engaging portion131as illustrated inFIG.21orFIG.22. In the present embodiment, a diameter dimension at the protruded surface1321is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.22. Moreover, the diameter dimension at the protruded surface1321may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8B and the outer peripheral surface of the cap11B, straddling a boundary between the sheath8B and the cap11B. Moreover, in the sheath8B and the cap11B, a portion corresponding to the engaging portion131is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4B according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiment described above with respect toFIGS.1-16, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above in a shape of the sheath8.

Hereinafter, for convenience of explanation, the sheath8according to the present embodiment will be denoted as sheath8C.

The sheath8C and the cap11correspond to a cover member.

FIG.23is a diagram illustrating a shape of the sheath8C according to the present embodiment.

In the sheath8C, a slant surface841, an outer diameter dimension, of which gradually decreases toward the proximal end side Ar2is arranged between an end portion on the distal end side Ar1connected to the cap11and an end portion on the proximal end side Ar2connected to the holding portion9as illustrated inFIG.23.

According to the present embodiment explained above, besides effects similar to those of the embodiment described above, a following effect is obtained.

In the present embodiment, because the slant surface841is arranged in the sheath8C, displacement of the tube TU toward the distal end side relative to the sheath8C can be prevented.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2D. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4D. Furthermore, the sheath8according to the present embodiment will be denoted as sheath8D. Moreover, the cap11according to the present embodiment will be denoted as cap11D.

The sheath8D and the cap11D correspond to a cover member. Moreover, the cap11D corresponds to a tubular portion.

FIG.24toFIG.26are diagrams illustrating an end portion of the treatment-instrument main unit4D according to the present embodiment. Specifically,FIG.24andFIG.25are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4D. WhileFIG.24illustrates a state in which the tube TU is removed,FIG.25illustrates a state in which the tube TU is attached.FIG.26is a cross-section of the distal end portion of the treatment-instrument main unit4D cut along a plane including the point of the hook portion1012and e center axis Ax.

The cap11D is made from a resin material, such as PEEK having electric insulation. This cap11D includes an engaging portion141(FIG.26), a connecting portion142(FIG.24,FIG.26) and an exposed portion143as illustrated inFIG.24toFIG.26.

The engaging portion141has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion141is a little smaller than an inner diameter dimension of the sheath8D. Moreover, respective inner diameter dimensions of the engaging portion141and e connecting portion142are a little larger than an outer dimension of the hook portion1012in the first direction Ar3.

On an outer peripheral surface of this engaging portion141, a ring-shaped concave portion1411that his a ring shape about the center axis Ax, and that is recessed toward the center axis Ax is arranged as illustrated inFIG.26.

The connecting portion142is a portion that connects an end portion of the engaging portion141on the distal and side Ar1and an end portion of the exposed portion143on the proximal end side Art, and has a substantially cylindrical shape surrounding the center axis Ax. In this connecting portion142, the end portion on the proximal end side Art connected to the engaging portion141has an outer diameter dimension larger than the engaging portion141. That is, on an outer peripheral surface of the cap110, a first step portion144(FIG.26) is arranged between the connecting portion142and the engaging portion141.

Moreover, an outer peripheral surface of the connecting portion142is formed by a proximal-end outer-peripheral surface1421, a first slant surface1422, and a first distal-end outer-peripheral surface1423continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.26.

The proximal-end outer-peripheral surface1421is a surface that linearly extends from a position abutting on the first step portion144toward the distal end side Ar1along the center axis Ax.

The first slant surface1422is a surface in which a diameter dimension gradually decreases from the position abutting on the proximal-end outer-peripheral surface1421toward the distal end side Ar1.

The first distal-end outer-peripheral surface1423is a surface that linearly extends from a position abutting on the first slant surface1422toward the distal end side Ar1along the center axis Ax.

The exposed portion143has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion142on the distal end side Ar1. In this exposed portion143, an end portion on the proximal end side Ar2connected to the connecting portion142has a larger outer diameter dimension than the first distal-end outer-peripheral surface1423. That is, on the outer peripheral surface of the cap11D, a second step portion.145(FIG.25,FIG.26) is arranged between the exposed portion143and the connecting portion142. Hereinafter, for convenience of explanation, a surface abutting on the second step portion145on the outer peripheral surface of the exposed portion143will be denoted as protruded surface1431.

Moreover, an outer peripheral surface of the exposed portion143is formed by the protruded surface1431, a second slant surface1432, and a second distal-end outer-peripheral surface1433continuously arranged from the proximal end side Art toward the distal end side Ar1as illustrated inFIG.24toFIG.26.

The protruded surface1431is a surface that linearly extends from a position abutting on the second step portion145toward the distal end side Ar1along the center axis Ax.

The second slant surface1432is a surface in which a diameter dimension gradually decreases from the position abutting on the protruded surface1431toward the distal end side Ar1.

The second distal-end outer-peripheral surface1433is a surface that linearly extends from a position abutting on the second slant surface1432toward the distal end side Ar1along the center axis Ax.

In the present embodiment, an inner diameter dimension of the end portion on the distal end side Ar1is smaller than the outer dimension of the hook portion1012in the first direction Ar3.

An outer diameter dimension at a distal end portion140having the second distal-end outer-peripheral surface1433(FIG.24toFIG.26) is smaller than an outer diameter dimension at the engaging portion141corresponding to a proximal end portion. Moreover, an outer diameter dimension at the distal end portion140is smaller than an outer dimension of the hook portion1012in the first direction Ar3. The distal end portion140is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4D or the like.

In the cap11D explained above, a slit146(FIG.24toFIG.26) that is cut linearly along the center axis Ax from a distal end of the exposed portion143toward the proximal end side Ar2is arranged on an end side in the first direction Ar3. This slit146corresponds to the first slit.

A width dimension of this slit146is a little larger than the outer dimension of the hook portion1012in the second direction Ar4.

At an end portion of the sheath8D on the distal end side Ar1, unlike the sheath8explained in the embodiment described above, the pair of engagement opening portions811and the positioning notch portion812are not provided.

In a manufacturing method of the treatment instrument2D according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101into the inside of the cap11D from the proximal end side Ar2of the cap11D. The operator makes the hook portion1012protrude out from the distal end side Ar1of the cap11D by moving the cap11D toward the proximal end side Ar2while putting the point of the hook portion1012in the slit146. Moreover, the operator moves the cap11D to the proximal end side Ar2, and inserts the engaging portion141into the inside of the sheath8D. The operator crimps the sheath8D to be deformed in a direction of shrinking the diameter of the sheath8D by using a not illustrated jig, and fits a deformed portion851(FIG.24,FIG.26) in the ring-shaped concave portion1411. Thus, the cap11D is attached to the sheath8D.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned between the protruded surface1431and the first slant surface1422, that is, on the first distal-end outer-peripheral surface1423as illustrated inFIG.26. In the present embodiment, a diameter dimension at the protruded surface1431is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.26. Moreover, the diameter dimension at the protruded surface1431may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8D and the outer peripheral surface of the cap11D, straddling a boundary between the sheath8D and the cap11D. Moreover, in the sheath8D and the cap11D, a portion corresponding to the engaging portion141and the first slant surface1422is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4D according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIG.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2E. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4E. Furthermore, the cap11according to the present embodiment will be denoted as cap11E. Because the sheath8according to the present embodiment is same as the sheath8D explained in the embodiment described above with respect toFIGS.24-26, it will be denoted as sheath8D.

The sheath8D and the cap11E correspond to a cover member. Moreover, the cap11E corresponds to a tubular portion.

FIG.27toFIG.29are diagrams illustrating a distal end portion of the treatment-instrument main unit4E according to the present embodiment. Specifically,FIG.27andFIG.28are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4E. WhileFIG.27illustrates a state in which the tube TU is removed,FIG.28illustrates a state in which the tube TU is attached.FIG.29is a cross-section of the distal end portion of treatment-instrument main unit4E cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11E is made from a resin material, such as PEEK, having electric insulation. This cap11E is, as illustrated inFIG.27orFIG.28, divided into two pieces, a first and a second caps11E1and11E2, at a plane including the point of the hook portion1012and the center axis Ax as a boundary. These first and the second caps11E1,11E2have shapes symmetric about the plane. In a state in which the first and the second caps11E1and11E2are assembled, the cap11E includes an engaging portion151(FIG.29), a connecting portion152(FIG.27,FIG.29), and a distal end portion153as illustrated inFIG.27toFIG.29.

The engaging portion151has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion151is a little smaller than an inner diameter dimension of the sheath80.

On an outer peripheral surface of this engaging portion151, as illustrated inFIG.29, a ring-shaped concave portion1511that has a ring shape about the center axis and that is recessed toward the center axis Ax is arranged.

The connecting portion152is a portion connecting an end portion of the engaging portion151on the distal end side Art and an end portion of the distal end portion153on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax. In the connecting portion152, the end portion on the proximal end side Ar2connected to the engaging portion151has an outer diameter larger than the engaging portion151. That is, on an outer peripheral surface of the cap11E, a first step portion154(FIG.27,FIG.29) is arranged between the connecting portion152and the engaging portion151.

Moreover, the outer peripheral surface of the connecting portion152is formed by a proximal-end outer-peripheral surface1521, a slant surface1522, and a distal-end outer-peripheral surface1523continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated in.FIG.27toFIG.29.

The proximal-end outer-peripheral surface1521is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the first step portion154.

The slant surface1522is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the proximal-end outer-peripheral surface1521.

The distal-end outer-peripheral surface1523is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on e slant surface1522.

The distal end portion153has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of connecting portion152on the distal end side Ar1. This distal end portion153has a larger outer diameter dimension than the distal-end outer-peripheral surface1523. That is, on the outer peripheral surface of the cap11E, a second step portion155(FIG.27,FIG.29) is arranged between the distal end portion153and the connecting portion152. Hereinafter, for convenience of explanation, an outer peripheral surface of the distal end portion153will be denoted as protruded surface1531.

The protruded surface1531is a surface that substantially linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the second step portion155.

An outer diameter dimension at the distal end portion153is smaller than an outer diameter dimension of the engaging portion151corresponding to a proximal end portion. Moreover, an outer diameter dimension at the distal end portion153is smaller than an outer dimension of the hook portion1012in the first direction Ar3. The distal end portion153is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4E or the like.

In a manufacturing method of the treatment instrument2E according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator assembles the first and the second caps11E1and11E2in a state in which the pillar portion1011is positioned between the first and the second caps11E1and11E2. In this state, the hook portion1012protrudes out from the distal end side Ar1of the cap11E in which the first and second caps11E1and11E2are assembled. The operator then moves the cap11E toward the proximal end side Ar2, to insert the engaging portion151into the inside of the sheath8D. The operator crimps the sheath8D to be deformed in a direction of shrinking the diameter of the sheath8D by using a not illustrated jig, and fits a deformed portion851(FIG.27,FIG.29) in the ring-shaped concave portion1511. Thus, the cap11E is attached to the sheath8D.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned between the protruded surface1531and the slant surface1522, that is, on the distal-end outer-peripheral surface1523as illustrated inFIG.29. In the present embodiment, a diameter dimension at the protruded surface1531is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.29. Moreover, the diameter dimension at the protruded surface1531may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8D and the outer peripheral surface of the cap11E, straddling a boundary between the sheath8D and the cap11E. Moreover, in the sheath8D and the cap11E, a portion corresponding to the engaging portion151and the slant surface1522is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4E according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Moreover, the cap11E is constituted of two pieces of parts, the first and the second caps11E1and11E2. Therefore, at step S3, a process of inserting the end effector101into the inside of the cap11E is not necessary, and assembly of the cap11E can be easily performed.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2F, Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4F. The sheath8according to the present embodiment will be denoted as sheath8F. Furthermore, the cap11according to the present embodiment will be denoted as cap11F.

The sheath8F and the cap11F correspond to a cover member. Moreover, the cap11F corresponds to a tubular portion.

FIG.30toFIG.32are diagrams illustrating a distal end portion of the treatment-instrument main unit4F according to the present embodiment. Specifically,FIG.30andFIG.31are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4F. WhileFIG.30illustrates a state in which the tube TU is removed,FIG.31illustrates a state in which the tube TU is attached.FIG.32is a cross-section of the distal end portion of the treatment-instrument main unit4F cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11F is made from a resin material, such as PEEK, having electric insulation. This cap11E includes an engaging portion161, a connecting portion162, and an exposed portion163as illustrated inFIG.30toFIG.32.

The engaging portion161has a substantially a cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion161is a little larger than an outer diameter dimension of an end portion of the sheath8F on the distal end side Ar1. Moreover, an inner diameter dimension of the engaging portion161is a little larger than an outer dimension of the hook portion1012in the first direction Ar3.

On an inner peripheral surface of this engaging portion161, as illustrated inFIG.32, a ring-shaped concave portion1611that has a ring shape about the center axis and that is recessed toward a direction away from the center axis Ax is arranged.

The connecting portion162is a portion connecting an end portion of the engaging portion161on the distal end side Ar1and an end portion of the exposed portion163on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax. In the present embodiment, an inner diameter dimension of the connecting portion162and an inner diameter dimension of the engaging portion161are substantially the same.

Moreover, the outer peripheral surface of the connecting portion162is formed by a first slant surface1621and a first distal-end outer-peripheral surface1622continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.30orFIG.32.

The first slant surface1621is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the engaging portion161.

The first distal-end outer-peripheral surface1622is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the first slant surface1621.

The exposed portion163has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion162on the distal end side Ar1. In this exposed portion163, an end portion on the proximal end side Ar2connected to the connecting portion162has a larger outer diameter dimension than the first proximal-end outer-peripheral surface1622. That is, on the outer peripheral surface of the cap11F, a step portion164(FIG.30,FIG.32) is arranged between the exposed portion163and the connecting portion162. Hereinafter, for convenience of explanation, a surface abutting on the step portion164on the outer peripheral surface of the exposed portion163will be denoted as protruded surface1631.

Moreover, an outer peripheral surface of the exposed portion163is formed by the protruded surface1631, a second slant surface1632, and a second distal-end outer-peripheral surface1633continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.30toFIG.32.

The protruded surface1631is a surface that linearly extends from a position abutting on the step portion164toward the distal end side Ar1along the center axis Ax.

The second slant surface1632is a surface in which a diameter dimension gradually decreases from the position abutting on the protruded surface1631toward the distal end side Ar1.

The second distal-end outer-peripheral surface1633is a surface that substantially linearly extends from a position abutting on the second slant surface1632toward the distal end side Ar1along the center axis Ax.

In the present embodiment, an inner diameter dimension of an end portion on the distal end side Ar1in the exposed portion163is smaller than the outer dimension of the hook portion1012in the first direction Ar3.

An outer diameter dimension at a distal end portion160(FIG.30toFIG.32) having the second distal-end outer-peripheral surface1633is smaller than an outer diameter dimension of the engaging portion161corresponding to a proximal end portion. Moreover, an outer diameter dimension at the distal end portion160is smaller than an outer dimension of the hook portion1012in the first direction Ar3. The distal end portion160is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4or the like.

In the cap11F explained above, a slit165(FIG.30toFIG.32) that is cut linearly along the center axis from a distal end of the exposed portion163toward the proximal end side Art is arranged on an end side in the first direction Ar3. This slit165corresponds to the first slit.

A width dimension of this slit165is a little larger an the outer dimension of the hook portion1012in the second direction Ar4.

At an end portion of the sheath8F on the distal end side Ar1, an outer diameter dimension and an inner diameter dimension gradually decrease toward the distal end side Ar1as illustrated inFIG.30orFIG.32. In the present embodiment, the inner diameter dimension of the end portion on the distal end side Ar1is smaller than the outer dimension of the hook portion1012in the first direction Ar3. In the end portion on the distal end side Ar1, a slit861(FIG.30) that pierces through from an outer peripheral surface to an inner peripheral surface and extends toward the proximal end side Ar2from a distal end of the sheath8F, to avoid interference with the hook portion1012when step S2is performed is arranged.

In a manufacturing method of the treatment instrument2F according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101into the inside of the cap11F from the proximal end side Ar2of the cap11F. The operator makes the hook portion1012protrude out from the distal end side Ar1of the cap11F by moving the cap11F toward the proximal end side Ar2while putting the point of the hook portion1012in the slit165. Moreover, the operator moves the cap11F to the proximal end side Ar2, and inserts an end portion of the sheath8F on the distal end side Ar1into the inside of the engaging portion161. The operator crimps the sheath8F to be deformed in a direction of expanding the diameter of the sheath8F by using a not illustrated jig, and fits a deformed portion862(FIG.32) in the ring-shaped concave portion1611. Thus, the cap11F is attached to the sheath8F.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned between the protruded surface1631and the first slant surface1621, that is, on the first distal-end outer-peripheral surface1622as illustrated inFIG.32. In the present embodiment, a diameter dimension at the protruded surface1631is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.32. Moreover, the diameter dimension at the protruded surface1631may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8F and the outer peripheral surface of the cap11F, straddling a boundary between the sheath8F and the cap11F. Moreover, in the sheath8F and the cap11F, a portion corresponding to the engaging portion161and the first slant surface1621is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4F according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2G. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4G. Furthermore, the cap11according to the present embodiment will be denoted as cap11G. Because the sheath8according to the present embodiment is substantially the same as the sheath8A explained in the embodiment described above with respect toFIGS.17-19, it will be denoted as sheath8A.

The sheath8A and the cap11G correspond to a cover member. Moreover, the cap11G corresponds to a tubular portion.

FIG.33toFIG.35are diagrams illustrating a distal end portion of the treatment-instrument main unit4G according to the present embodiment.FIG.36is a diagram illustrating a first cap11G1. Specifically,FIG.33andFIG.34are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4G. WhileFIG.33illustrates a state in which the tube TU is removed,FIG.34illustrates a state in which the tube TU is attached.FIG.35is a cross-section of the distal end portion of the treatment-instrument main unit4G cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11G is made from a resin material, such as PEEK, having electric insulation. This cap11G is, as illustrated inFIG.33,FIG.34, orFIG.36, divided into two pieces, a first and a second caps11G1and11G2, at a plane including the point of the hook portion1012and the center axis Ax as a boundary. These first and the second caps11G1,11G2have shapes symmetric about the plane. In a state in which the first and the second caps11G1and11G2are assembled, the cap11G includes an engaging portion171(FIG.33,FIG.35,FIG.36), a connecting portion172(FIG.33,FIG.35,FIG.36), and a distal end portion173as illustrated inFIG.33toFIG.36.

The engaging portion171has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion171is a little smaller than an inner diameter dimension of the sheath8A.

On an outer peripheral surface of this engaging portion171, a pair of convex portions1711respectively protruding in a direction away from the center axis Ax are arranged as illustrated inFIG.33orFIG.36. These pair of the convex portions1711are arranged respectively in the first and the second caps11G1and11G2, and is positioned at rotationally symmetric positions by 180° about the center axis Ax.

The connecting portion172is a portion connecting an end portion in the engaging portion171on the distal end side Ar1and an end portion in the distal end portion153on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax. In the connecting portion172, an end portion on the proximal end side Ar2connected to the engaging portion171has an outer diameter dimension larger than the engaging portion171. That is, on an outer peripheral surface of the cap11G, a first step portion174(FIG.35,FIG.36) is arranged between the connecting portion.172and the engaging portion171.

Moreover, the outer peripheral surface of the connecting portion172is formed by a proximal-end outer-peripheral surface1721, a slant surface1722, and a distal-end outer-peripheral surface1723continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.35toFIG.36.

The proximal-end outer-peripheral surface1721is a surface that linearly extends toward the distal end side Ar1along the center axis from a position abutting on the first step portion174.

The slant surface1722is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the proximal-end outer-peripheral surface1721.

The distal-end outer-peripheral surface1723is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the slant surface1722.

The distal end portion173has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion172on the distal end side Ar1. This distal end portion173has a larger outer diameter dimension than the distal-end outer-peripheral surface1723. That is, on the outer peripheral surface of the cap11G, a second step portion175(FIG.33,FIG.35,FIG.36) is arranged between the distal end portion173and the connecting portion172. Hereinafter, for convenience of explanation, the outer peripheral surface of the distal end portion173will be denoted as protruded surface1731.

The protruded surface1731is a surface that substantially linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the second step portion175.

An outer diameter dimension at the distal end portion173is smaller than an outer diameter dimension of the engaging portion171corresponding to a proximal end portion. Moreover, the outer diameter dimension at the distal end portion173is smaller than the outer dimension of the hook portion1012in the first direction Ar3. The distal end portion173is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4G, or the like.

In a manufacturing method of the treatment instrument2G according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator assembles the first and the second caps11G1and11G2in a state in which the pillar portion1011is positioned between the first and the second caps11G1and11G2. In this state, the hook portion1012protrudes out from the distal end side Ar1of the cap11G in which the first and the second caps11G1and11G2are assembled. The operator then moves the cap11G toward the proximal end side Ar2, to insert the engaging portion171into the inside of the sheath8A. The cap11G is attached to the sheath8A as the convex portion1711is engaged with the engagement opening portion822. That is, the cap11G is attached to the sheath8A by a snap-fit mechanism.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned between the protruded surface1731and the slant surface1722, that is, on the distal-end outer-peripheral surface1723as illustrated inFIG.35. In the present embodiment, a diameter dimension at the protruded surface1731is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.35. Moreover, the diameter dimension at the protruded surface1731may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8A and the outer peripheral surface of the cap11G, straddling a boundary between the sheath8A and the cap11F. Moreover, in the sheath BF and the cap11G, a portion corresponding to the engaging portion171and the slant surface1722is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4G according to the present embodiment explained above is adopted, effects similar to those of the embodiments described above with respect toFIGS.1-29are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2H, Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4H. Furthermore, the cap11according to the present embodiment will be denoted as cap11H. Because the sheath8according to the present embodiment is substantially the same as the sheath8A explained in the embodiment described above with respect toFIGS.17-19, it will be denoted as sheath8A.

The sheath8A and the cap11H correspond to a cover member. Moreover, the cap11H corresponds to a tubular portion.

FIG.37toFIG.39are diagrams illustrating a distal end portion of the treatment-instrument main unit4H according to the present embodiment. Specifically,FIG.37andFIG.38are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4H. WhileFIG.37illustrates a state in which the tube TU is removed,FIG.38illustrates a state in which the tube TU is attached.FIG.39is a cross-section of the distal end portion of the treatment-instrument main unit4H cut along a plane including the point of the hook portion1012and the center axis Ax.

The cap11H is made from a resin material, such as PEEK, having electric insulation. This cap11H is, as illustrated inFIG.37orFIG.38, divided into two pieces, a first and a second caps11H1and11H2, at a plane including the point of the hook portion1012and the center axis Ax as a boundary. These first and the second caps11H1,11H2have shapes symmetric about the plane. In a state in which the first and the second caps11H1and11H2are assembled, the cap11H includes an engaging portion181(FIG.37,FIG.39), a connecting portion182(FIG.37,FIG.39), and a distal end portion183as illustrated inFIG.37toFIG.39.

The engaging portion181includes an engaging-portion main unit1811and a pair of arm portions1812.

The engaging-portion main unit1811has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging-portion main unit1811is substantially the same as the outer diameter dimension of the sheath8A.

The pair of the arm portions1812are arranged respectively in the first and the second caps11H1and11H2, and are positioned at rotationally symmetric positions about the center axis Ax by 180°. More specifically, the pair of the arm portions1812oppose to each other from a proximal end of the engaging-portion main unit1811and protrude toward the proximal end side Ar2, and is capable of elastic deformation in a direction of becoming close to and apart from each other, from a proximal end on the distal end side Ar1as a base point. A separation distance between surfaces opposing to each other in these in these pair of the arm portions1812is substantially the same as a separation distance between outer surfaces of the pair of the flat portions821in the sheath8A. In these pair of the arm portions1812, convex portions (not illustrated) are arranged respectively on surfaces opposing to each other on the proximal end side Ar2.

The connecting portion182is a portion connecting an end portion in the engaging portion181on the distal end side Ar1and an end portion in the distal end portion183on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax.

Moreover, the outer peripheral surface of the connecting portion182is formed by a slant surface1821and a distal-end outer-peripheral surface1822continuously arranged from the proximal end side Ar2toward the distal end side Ar1as illustrated inFIG.37toFIG.39.

The slant surface1821is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the engaging portion181.

The distal-end outer-peripheral surface1822is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the slant surface1321.

The distal end portion183has a substantially cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion182on the distal end side Ar1. This distal end portion183has a larger outer diameter dimension than the distal-end outer-peripheral surface1822. That is, on the outer peripheral surface of the cap11H, a step portion184(FIG.37toFIG.39) is arranged between the distal end portion183and the connecting portion182. Hereinafter, for convenience of explanation, the outer peripheral surface of the distal end portion183will be denoted as protruded surface1831.

The protruded surface1831is a surface that substantially linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the step portion184.

An outer diameter dimension at the distal end portion183is smaller than an outer diameter dimension at the engaging-portion main unit1811corresponding to a proximal end portion. Moreover, the outer diameter dimension at the distal end portion183is smaller than the outer dimension of the hook portion1012in the first direction Ar3. The distal end portion183is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4H, or the like.

In a manufacturing method of the treatment instrument2H according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S9according to the present embodiment, an operator assembles the first and the second caps11H1and11H2in a state in which the pillar portion1011and the sheath8A are positioned between the first and the second caps11H1and11H2, and engages respective convex portions (not illustrated) in the pair of the arm portions1812with the engagement opening portion822, The cap11H is attached to the sheath8A as the tube TU is attached by step S4.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned between the protruded surface1831and the slant surface1821, that is, on the distal-end outer-peripheral surface1822as illustrated inFIG.38orFIG.39. In the present embodiment, a diameter dimension at the protruded surface1831is substantially the same as an outer diameter dimension of the tube TU at the distal end as illustrated inFIG.39. Moreover, the diameter dimension at the protruded surface1831may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8A and the outer peripheral surface of the cap11H, straddling a boundary between the sheath8A and the cap11F. Moreover, in the sheath8A and the cap11H, a portion corresponding to the pair of the arm portions1812and the slant surface1821is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4H according to the present embodiment explained above is adopted, effects similar to those of the embodiments described above with respect toFIGS.1-29are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the sheath8and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2I. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4I. Furthermore, the sheath8according to the present embodiment will be denoted as sheath8I. Moreover, the cap11according to the present embodiment will be denoted as cap11I.

The sheath8I and the cap11I correspond to a cover member. Moreover, the cap11I corresponds to a tubular portion.

FIG.40toFIG.41are diagrams illustrating a distal end portion of the treatment-instrument main unit4I according to the present embodiment.FIG.42andFIG.43are diagrams illustrating the cap11I1. Specifically,FIG.40andFIG.41are diagrams illustrating an external view of the distal end portion of the treatment-instrument main unit4I. WhileFIG.40illustrates a state in which the tube TU is removed,FIG.41illustrates a state in which the tube TU is attached.FIG.42is a diagram illustrating the cap11I before a pair of living hinges11I3,11I4are bent.FIG.43is a diagram illustrating the cap11I after the pair of the living hinges11I3,11I4are bent.

The cap11I is made from a resin material, such as PEEK, having electric insulation. This cap11I includes a first and a second caps11I1,11I2that are joined by the pair of living hinges11I3,11I4as illustrated inFIG.42. These first and the second caps11I1,11I2have shapes symmetric about the plane including the point of the hook portion1012and the center axis Ax as a boundary. In a state in which the first and the second caps11I1and11I2are assembled, the cap11I includes an engaging portion191(FIG.40,FIG.42,FIG.43), a connecting portion192(FIG.40,FIG.42,FIG.43), and an exposed portion193as illustrated inFIG.40toFIG.43.

The engaging portion191has a substantially cylindrical shape coaxial with the center axis Ax. In the present embodiment, an outer diameter dimension of the engaging portion191is a little smaller than an inner diameter dimension of the sheath8I. On an outer peripheral surface of the engaging portion191, a pair of engagement protrusions1911are arranged as illustrated inFIG.40FIG.42, orFIG.43.

The pair of the engagement protrusions1911are arranged respectively in the first and the second caps11I1and11I2. More specifically, the pair of the engagement protrusions1911respectively protrude in a direction away from the center axis Ax from the outer peripheral surface of the engaging portion191, and linearly extend toward the distal end side Ar1from a proximal end of the engaging portion191while opposing to each other.

The connecting portion192is a portion connecting an end portion in the engaging portion191on the distal end side Ar1and an end portion in the exposed portion193on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax. In the connecting portion192, an outer diameter dimension is larger than the engaging portion191. That is, on an outer peripheral surface of the cap11I, a first step portion194(FIG.40,FIG.42,FIG.43) is arranged between the connecting portion192and the engaging portion191.

The exposed portion193has a substantially cylindrical shape surrounding the center axis and is arranged at an end portion of the connecting portion192on the distal end side Ar1. In this exposed portion193, an end portion on the proximal end side Ar2connected to the connecting portion192has a larger outer diameter dimension than the connecting portion192. That is, on the outer peripheral surface of the cap11I, a second step portion195(FIG.40toFIG.43) is arranged between the exposed portion193and the connecting portion192. Hereinafter, for convenience of explanation, a surface abutting on the second step portion195on the outer peripheral surface of the exposed portion193will be denoted as protruded surface1931.

Moreover, the outer peripheral surface of the exposed portion193is formed, as illustrated inFIG.40toFIG.43, by the protruded surface1931, a slant surface1932, and a distal-end outer-peripheral surface1933arranged continuously from the proximal end side Ar2toward the distal end side Ar1.

The protruded surface1931is a surface that linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the second step portion195.

The slant surface1932is a surface in which a diameter dimension decreases toward the distal end side Ar1from a position abutting on the protruded surface1931.

The distal-end outer-peripheral surface1933is a surface that substantially linearly extends toward the distal end side Ar1along the center axis Ax from a position abutting on the slant surface1932.

An outer diameter dimension of a distal end portion190(FIG.40,FIG.41,FIG.43) having the distal-end outer-peripheral surface1933is smaller than an outer diameter dimension n the engaging portion191corresponding to a proximal end portion. Moreover, the outer diameter dimension in the distal end portion190is smaller than an outer dimension of the hook portion1012in the first direction Ar3. The distal end portion190is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4I, or the like.

In an end portion of the sheath8I on the distal end side Ar1, as illustrated inFIG.40, a pair of engagement notch portions871linearly cut along the center axis Ax from the distal end toward the proximal end side Ar2, and with which the pair of the engagement protrusions1911are engaged are arranged. This engagement notch portion871includes a narrow portion8711that is positioned on the distal end side Ar1, and a wide portion8712that is positioned on the proximal end side Ar2, and that has a larger width than the narrow portion8711.

In a manufacturing method of the treatment instrument21according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator bends a pair of living hinges11E3,11E4, to assemble the first and the second caps11I1and11I2in a state in which the pillar portion1011is positioned inside the cap11I (upper side inFIG.42). In this state, the hook portion1012protrudes out from the distal end side Ar1of the cap11I in which the first and the second caps11I1,11I2are assembled. The operator moves the cap11I to the proximal end side Ar2, and inserts the engaging portion191into the inside of the sheath8I while putting the pair of the engagement protrusions1911in the engagement notch portions871. The cap11I is attached to the sheath8I as the pair of the engagement protrusions1911are engaged with the wide portions8712in the engagement notch portions871.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned on the outer peripheral surface of the connecting portion192, In the present embodiment, a diameter dimension at the protruded surface1931is substantially the same as an outer diameter dimension of the tube TU at the distal end. Moreover, the diameter dimension at the protruded surface1931may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8I and the outer peripheral surface of the cap11I, straddling a boundary between the sheath8I and the cap11I. Moreover, in the sheath8I and the cap11I, a portion corresponding to the engaging portion191is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4I according to the present embodiment explained above is adopted, effects similar to those of the embodiments described above with respect toFIGS.1-29are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above in a structure of the distal end portion of the treatment-instrument main unit4(structure of the vibration transmission member10and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2J. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4J. Furthermore, the vibration transmission member10according to the present embodiment will be denoted as vibration transmission member10J. Moreover, the cap11according to the present embodiment will be denoted as cap11J.

The sheath8and tie cap11J correspond to a cover member. Moreover, the cap11J corresponds to a tubular portion.

FIG.44is a diagram illustrating a distal end portion of the treatment-instrument main unit4J according to the present embodiment.FIG.44, for convenience of explanation, the tube TU is illustrated with an alternate long and short dash line.FIG.45andFIG.46are diagrams illustrating a distal end portion of the vibration transmission member10J. Specifically,FIG.45illustrates the vibration transmission member10J viewed along the second direction Ar4.FIG.46illustrates the vibration transmission member10J along the first direction Ar3.

The vibration transmission member10J differs from the vibration transmission member10explained in the embodiment described above in a shape of the end effector101. Hereinafter, for convenience of explanation, the end effector according to the present embodiment will be denoted as end effector101J.

The end effector101J includes, as illustrated inFIG.44toFIG.46, a pillar portion1013that extends along the center axis Ax and a spatula portion1014that is arranged at an end portion of the pillar portion1013on the distal end side Ar1.

The spatula portion1014has a larger width dimension than a width dimension (outer dimension in the first direction Ar3) of the pillar portion1013, and is curved along the second direction Ar4as it approaches the distal end Ar1.

The cap11J is made from a resin material, such as PEEK, PTFE, and PEA, having electric insulation. This cap11J includes, as illustrated inFIG.44, an engaging portion201, a connecting portion202, and a distal end portion203.

The engaging portion201has a shape similar to the engaging portion111explained in the embodiment described above. That is, the engaging portion201includes a pair of claw portions2011(FIG.44) similar to the pair of the claw portions1112explained in the embodiment described above. In the present embodiment, an inner diameter dimension of the engaging portion201is a little larger than a width dimension of the spatula portion1014.

The connecting portion202is a portion connecting an end portion of the engaging portion201on the distal end side Ar1and an end portion of the distal end portion203on the proximal end side Ar2, and has a substantially cylindrical shape surrounding the center axis Ax in the connecting portion.202, the end portion on the proximal end side Ar2connected to the engaging portion201has an outer diameter larger than the enraging portion201. That is, on an outer peripheral surface of the cap11J, a first step portion204(FIG.44) is arranged between the connecting portion202and the engaging portion201.

In this connecting portion202, a substantially center portion in the direction toward the center axis Ax is smaller in outer dimension (thickness dimension) in the second direction Ar4than other portions. The thickness dimension of the connecting portion202gradually increases from the substantially center portion toward the distal end side Ar1and the proximal end side Ar2, Moreover, in the connecting portion202, the substantially center portion has an outer dimension in the first direction Ar3(width dimension) smaller than other portions. The width dimension of the connecting portion202gradually increases from the substantially the center portion toward the distal end side Ar1and the proximal end side Ar2.

Hereinafter, the substantially center portion, the outer dimensions in the first and the second directions Ar3, Ar4of which are smallest in the connecting portion202will be denoted as intermediate portion205(FIG.44).

The outer dimension in the first direction Ar1in the intermediate portion205is smaller than the outer dimension in the first direction Ar3in other portions in the cap11J, and is smaller than the width dimension of the spatula portion1014. The intermediate portion205is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4J, or the like.

In the present embodiment, an inner dimension of the intermediate portion205is as follows.

Namely, the inner dimension in the first direction Ar3in the intermediate portion205is smaller than the width dimension of the spatula portion1014. Moreover, the inner dimension in the second direction Ar4in the intermediate portion205is larger than the thickness dimension (outer dimension in the second direction Ar4) of the spatula portion1014.

On the other hand, in the connecting portion202, portions other than the intermediate portion205has an inner dimension enabling insertion of the spatula portion1014.

In the connecting portion202explained above, a slit206(FIG.44) that is arranged over the intermediate portion205, and that linearly extends along the center axis Ax is arranged on both end sides in the first direction Ar3. This slit206corresponds to the first slit.

A width dimension of this slit206is a little larger than the thickness dimension of the spatula portion1014.

The distal end portion203has a cylindrical shape surrounding the center axis Ax, and is arranged at an end portion of the connecting portion202on the distal end side Ar1. This distal end portion203has respective outer diameter dimensions in the first and the second directions Ar3, Ar4larger than the distal end portion of the connecting portion202on the distal end side Ar1. That is, on the outer peripheral surface of the cap11J, a second step portion207(FIG.44) is arranged between the distal end portion203and the connecting portion202. Hereinafter, for convenience of explanation, an outer peripheral surface of the distal end portion203will be denoted as protruded surface2031.

In the present embodiment, the distal end portion203has an inner dimension enabling insertion of the spatula portion1014.

The outer dimension of the distal end portion.203in the second direction Ar4is smaller than an outer dimension of the engaging portion201corresponding to a proximal end portion. The distal end portion203is made thin together with the intermediate portion205, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4J.

In a manufacturing method of the treatment instrument2J according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101J into the inside of the cap11J from the proximal end side Ar2of the cap11. The operator moves the cap11J to the proximal end side Ar2while putting an end portion of the spatula portion1014on the first direction Ar2in the slit206, to make the spatula portion1014protrude out from the distal end side Ar1of the cap11J. Moreover, the operator moves the cap11J to the proximal end side Ar2, to insert the engaging portion201into the inside of the sheath8. The cap11J is attached to the sheath6as the claw portion2011engages with the engagement opening portion811. That is, the cap11J is attached to the sheath8by a snap-fit mechanism.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned on the outer peripheral surface of the connecting portion202. In the present embodiment, respective diameter dimensions of the protruded surface2031in the first and the second directions Ar3, Ar4are substantially the same as respective outer diameter dimensions of the tube TU at the distal end in the first and the second directions Ar3, Ar4. Moreover, the respective diameter dimensions of the protruded surface2031in the first and the second directions Ar3, Ar4may be equal to or smaller than the respective outer diameter dimensions of the tube TU in the first and the second directions Ar3, Ar4at the distal end, or may be equal to or larger than the respective outer diameter dimensions of the tube TU in the first and the second directions Ar3, Ar4at distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8and the outer peripheral surface of the cap11J, straddling a boundary between the sheath8and the cap11J. Moreover, in the sheath8and the cap11J, a portion corresponding to the engaging portion201is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4J according to the embodiment explained above is adopted, effects similar to those of the embodiment described above with respect toFIGS.1-16are obtained.

Next, another exemplary embodiment will be explained.

In the following explanation, identical reference symbols are assigned to components identical to those of the embodiments described above, and detailed explanation thereof will be omitted or simplified.

The present embodiment differs from the embodiment described above with respect toFIGS.1-16in a structure of the distal end portion of the treatment-instrument main unit4(structure of the vibration transmission member10and the cap11).

Hereinafter, for convenience of explanation, the treatment instrument2according to the present embodiment will be denoted as treatment instrument2K. Moreover, the treatment-instrument main unit4according to the present embodiment will be denoted as treatment-instrument main unit4K. Furthermore, the cap11according to the present embodiment will be denoted as cap11K. Because the vibration transmission member10according to present embodiment has a shape similar to that of the vibration transmission member10J explained in the embodiment described above with respect toFIGS.44-46, it will be denoted as vibration transmission member10J.

The sheath8and the cap11K correspond to a cover member. Moreover, the cap11K corresponds to a tubular portion.

FIG.47andFIG.48are diagrams illustrating a distal end portion of the treatment-instrument main unit4K according to the present embodiment. Specifically,FIG.47is a diagram illustrating a state in which the spatula portion1014is inserted into inside of the cap11K.FIG.48is a diagram illustrating an external view of the treatment-instrument main unit4K.

The cap11K is made from a resin material, such as PTFE or PFA, having electric insulation. This cap11K includes, as illustrated inFIG.47orFIG.48, a first member211and a second member212.

The first member211is arranged on the proximal end side Ar2relative to the second member212. This first member211includes an engaging portion213having a shape similar to the engaging portion201explained in the embodiment described above with respect toFIGS.44-46. That is, the engaging portion213includes a pair of claw portions2131similar to the pair of the claw portions2011explained in the embodiment described above.

The second member212is joined to the first member211swingably along the second direction Ar4by a joint portion214(FIG.47) that extends toward the distal end side Ar1from an end portion of the engaging portion213on the distal end side Ar1. This second member212includes a connecting portion215and a distal end portion216as illustrated inFIG.47.

The connecting portion215has a cylindrical shape coaxial with the center axis and is connected to an end portion of the joint portion214on the distal end side Ar1. In the present embodiment, an inner diameter dimension of the connecting portion215is smaller than the width dimension of the spatula portion1014.

The distal end portion216has a substantially cylindrical shape coaxial with the center axis Ax, and is arranged at an end portion of the connecting portion215on the distal end side Ar1. This distal end portion216has a larger outer diameter dimension than the connecting portion215. That is, on an outer peripheral surface of the second member212, a step portion217(FIG.47,FIG.48) is arranged between the distal end portion216and the connecting portion.215, Hereinafter, for convenience of explanation, an outer peripheral surface of the distal end portion216will be denoted as protruded surface2161.

In the present embodiment, an inner diameter dimension of the distal end portion216is smaller than the width dimension of the spatula portion1014.

An outer diameter dimension of the distal end portion216is smaller than an outer diameter dimension of the engaging portion213corresponding to the proximal end portion. An outer dimension of the distal end portion216in the first direction Ar3is smaller than the width dimension of the spatula portion1014. The distal end portion216is made thin, and thereby acquires a function of providing a field of view for an operator that uses the treatment-instrument main unit4K, or the lik.

In a manufacturing method of e treatment instrument2K according to the present embodiment, step S3is different from the manufacturing method (FIG.8) of the treatment instrument2explained in the embodiment described above.

At step S3according to the present embodiment, an operator inserts the end effector101J into the inside of the engaging portion213from the proximal end side Art of the engaging portion213as illustrated inFIG.47. Moreover, because the cap11K is made from a relatively flexible material, such as PTFE or PFA, the operator inserts the end effector101J into the inside of the connecting portion215from the proximal end side of the connecting portion215while deforming the cap11K. Thus, the spatula portion1014protrudes from the distal end side Ar1of the distal end portion216. As the end effector101J is inserted thereinside, the second member212moves until a center axis of the second member212coincides with the center axis Ax from an upper side to a lower side inFIG.47, following a curved shape of the spatula portion1014. The cap11K is attached to the sheath8as the claw portion2131engages with the engagement opening portion811. That is, the cap11K is attached to the sheath8by a snap-fit mechanism.

At step S4, in a state in which the tube TU is attached, the distal end of the tube TU is positioned on an outer-peripheral surface of the connecting portion215as illustrated inFIG.48. In the present embodiment, a diameter dimension at the protruded surface2161is substantially the same as an outer diameter dimension of the tube TU at the distal end. Moreover, the diameter dimension at the protruded surface2161may be equal to or smaller than the outer diameter dimension of the tube TU at the distal end, or may be equal to or larger than the outer diameter dimension of the tube TU at the distal end.

As described above, the tube TU is arranged at a position enabling to cover both the outer peripheral surface of the sheath8and the outer peripheral surface of the cap11K, straddling a boundary between the sheath8and the cap11K. Moreover, in the sheath8and the cap11K, a portion corresponding to the engaging portion213is an overlap area that overlaps in a radial direction. The tube TU covers the overlap area.

Also when the treatment-instrument main unit4K according to the present embodiment explained above is adopted, effects similar to those of the embodiment described above are obtained.

Embodiments to implement the disclosure have so far been explained, but the disclosure is not to be limited only to the embodiments described above.

In the embodiments described above, a treatment instrument according to the disclosure is configured to apply both an ultrasonic energy and a hi frequency energy to a target site, but it is not limited thereto, and may be configured to apply at least either energy out of an ultrasonic energy, a high frequency energy, and a thermal energy. “Applying a thermal energy to a target site” means that propagating heat generated by a heater or the like to a target site.

In the embodiments described above, the caps11,11A,11B, and11D to11K are adopted as a tubular portion, but not limited thereto, a sheath may be adopted. That is, without using the caps11,11A,11B, and11D to11K, a distal end portion of a sheath may be formed in a shape similar to the caps11,11A,11B, and11D to11K.

In the embodiments described above, step S2and step S3may be performed in the inverse order.

In the embodiment described above with respect toFIGS.1-16, the cap11is structured without arranging the first and the second slits116,117, and the cap11is constituted of an elastic member. At step S3, the end effector101is inserted into the inside of the cap11while deforming the cap11, and makes the end effector101protrude out from the distal end side Ar1of the cap11.

According to the cover member and the treatment instrument according to the disclosure, a field of view can be acquired.

It should be noted that the present technology can have the following configurations.

A treatment instrument including:

a tubular sheath that extends from a distal end to a proximal end to determine a longitudinal axis direction;

a tubular cap that is attached to a distal end of the sheath;

an end effector that protrudes from a distal end of the cap, the end effector being configured to perform treatment on a living tissue; and

a tube that is arranged at a position at which the tube covers both of an outer peripheral surface of the sheath and an outer peripheral surface of the cap across a boundary between the sheath and the cap, the tube being configured to contract in a radial direction perpendicular to the longitudinal axis direction.

The treatment tool according to Appendix 1, in which

the sheath and the cap include overlap regions where the sheath and the cap overlap with each other in the radial direction, and

the tube is configured to cover the overlap regions.

The treatment instrument according to Appendix 2, in which

the outer peripheral surface of the cap includes a reduced diameter portion whose dimension in the radial direction decreases toward a distal end of the cap in the overlap region, and

the tube covers the reduced diameter portion.

The treatment instrument according to Appendix 3, in which

the outer peripheral surface of the cap includes a protruded portion that is arranged between the distal end of the cap and the reduced diameter portion, the protruded portion jutting out outward in the radial direction, and

the distal end of the cap is located between the protruded portion and the reduced diameter portion.

The treatment instrument according to Appendix 4, in which

a dimension of the protruded portion in the radial direction is equal to or less than a dimension of an outer peripheral surface of a distal end of the tube in the radial direction.

The treatment instrument according to Appendix 4, in which

a dimension of the protruded portion in the radial direction is equal to or larger than a dimension of an outer peripheral surface of a distal end of the tube in the radial direction.

The treatment instrument according to Appendix 2, in which

the cap is detachably attached to the sheath.

The treatment instrument according to Appendix 1, in which

the cap is made of an electrically insulating resin material.

The treatment instrument according to Appendix 4, in which

the outer peripheral surface of the cap has a dimension in the radial direction that decreases from the protruded portion toward the distal end of the cap.

The treatment instrument according to Appendix 1, in which

the cap includes a slit for preventing interference with the end effector.

The treatment instrument according to Appendix 1, further including:

a vibration transmission member inserted into the sheath and the cap and transmitting ultrasonic vibration along the longitudinal axis direction, the end effector being arranged at a distal end of the vibration transmission member.

A tubular cap used for a treatment instrument including an end effector configured to treat a living tissue, the cap including:

an engaging portion configured to engage with a distal end of a tubular sheath extending from a distal end toward a proximal end to define a longitudinal axis direction,

an outer peripheral surface of the cap including a reduced diameter portion whose dimension in a radial direction perpendicular to the longitudinal axis direction decreases from the engaging portion toward a distal end of the cap,

an outer surface of the engaging portion and the reduced diameter portion being arranged at positions straddling a boundary between the sheath and the cap and being covered together with an outer peripheral surface of the sheath by a tube configured to contract in the radial direction.

The cap according to Appendix 12, in which the engaging portion is a region that overlaps the sheath in the radial direction.

The cap according to Appendix 13, in which the outer peripheral surface of the cap includes a protruded portion that is arranged between the distal end of the cap and the reduced diameter portion, the protruded portion jutting out outward in the radial direction, and

the distal end of the cap is located between the protruded portion and the reduced diameter portion.

The cap according to Appendix 14, in which

a dimension of the protruded portion in the radial direction is equal to or less than a dimension of an outer peripheral surface of a distal end of the tube in the radial direction.

The cap according to Appendix 14, in which a dimension of the protruded portion in the radial direction is equal to or larger than a dimension of an outer peripheral surface of a distal end of the tube in the radial direction.

The cap according to Appendix 12, in which

the cap is made of an electrically insulating resin material.

The cap according to Appendix 14, in which

the outer peripheral surface of the cap has a dimension in the radial direction that decreases from the protruded portion toward the distal end of the cap.

The cap according to Appendix 12, further including

a slit for preventing interference with the end effector.

A method of manufacturing a treatment instrument, the method including:

inserting a shaft into a tubular sheath that extends from a distal end to a proximal end to determine a longitudinal axis direction, the shaft being provided with an end effector at a distal end of the shaft, the end effector being configured to treat a living tissue;

attaching the tubular cap to a distal end of the sheath;

arranging a tube at a position at which the tube covers both of an outer peripheral surface of the sheath and an outer peripheral surface of the cap across a boundary between the sheath and the cap; and

contracting the tube in a radial direction perpendicular to the longitudinal axis direction.