Endoscopic surgical device and overtube

1. An endoscopic surgical device comprising:

an endoscope that is configured to observe an inside of a body cavity;

a treatment tool that is configured to inspect or treat an affected part within the body cavity; and

an overtube that is configured to guide the endoscope and the treatment tool into the body cavity,

wherein the overtube includes

an overtube body that is configured to pass through a body wall and is configured to be inserted into the body cavity,

an endoscope insertion passage that is provided inside the overtube body and allows the endoscope to be inserted therethrough so as to be movable forward and backward,

a treatment tool insertion passage that is provided inside the overtube body and allows the treatment tool to be inserted therethrough so as to be movable forward and backward,

an interlocking member which is configured to be movable forward and backward inside the overtube body, has an endoscope-coupled part to be coupled to the endoscope inserted through the endoscope insertion passage and a treatment tool-coupled part to be coupled to the treatment tool inserted through the treatment tool insertion passage, and has a dead zone where the forward and backward movement of either one of the endoscope and the treatment tool does not interlock with the movement of the other, and a sensing zone where the forward and backward movement of either one of the endoscope and the treatment tool interlocks with the movement of the other, and

a side surface opening that is formed to pass through a side wall of the overtube body, allows an inner cavity of the overtube body and the inside of the body cavity to communicate with each other when the overtube body is inserted into the body cavity, and sends a fluid into the body cavity through the inner cavity of the overtube body, and

wherein the side surface opening is configured to be openable and closable by the forward and backward movement of the interlocking member.

2. The endoscopic surgical device according to claim 1 , further comprising:

an inner needle that includes a first elongated shaft part inserted through the endoscope insertion passage and a second elongated shaft part inserted through the treatment tool insertion passage, and that is assembled into the overtube body in a state where respective distal end parts of the first shaft part and the second shaft part are made to protrude from the overtube body when being inserted into the body cavity,

wherein the interlocking member is positioned at a position that faces the side surface opening in a state where the inner needle has been assembled into the overtube body, and the side surface opening is closed by one wall surface of the interlocking member.

3. The endoscopic surgical device according to claim 2 ,

wherein the first shaft part or the second shaft part is provided with an engagement part that engages with the interlocking member, and

wherein the interlocking member is positioned at a position that aces the side surface opening by the engagement part of the first shaft part or the second shaft part being engaged therewith, in a state where the inner needle has been assembled into the overtube body.

4. The endoscopic surgical device according to claim 3 ,

wherein the inner needle includes a head part that links a base end of the first shaft part and a base end of the second shaft part, and a fixing mechanism that is provided at the head part and detachably fixes the head part to the overtube, and

wherein the interlocking member is arranged at a position that faces the side surface opening when the head part has been fixed to the overtube by the fixing mechanism.

5. The endoscopic surgical device according to claim 3 ,

wherein the first shaft part or the second shaft part includes a smaller-diameter part that is arranged on a distal end side, and a larger-diameter part that is connected to a base end side of the smaller-diameter part,

wherein the engagement part is constituted by a stepped part formed at a boundary position between the smaller-diameter part and the larger-diameter part, and

wherein the interlocking member includes a hole that is larger than an external diameter of the smaller-diameter part and is smaller than an external diameter of the larger-diameter part, and an abutment part that is a peripheral part of the hole and against which the stepped part abuts.

6. The endoscopic surgical device according to claim 3 ,

wherein the engagement part includes a frictional engagement part that frictionally engages with the interlocking member.

7. The endoscopic surgical device according to claim 1 ,

wherein the side surface opening is provided on a distal end side of the overtube body, and is closed by one wall surface of the interlocking member when the interlocking member has moved to a foremost position of a movable range thereof.

8. The endoscopic surgical device according to claim 1 ,

wherein the interlocking member includes a slider member that is coupled to the endoscope and moves forward and backward integrally with the endoscope, and a sleeve member that is coupled to the treatment tool and moves forward and backward integrally with the treatment tool, and

wherein a range where the sleeve member is movable forward and backward with respect to the slider member is limited.

9. The endoscopic surgical device according to claim 1 ,

wherein a following formula is satisfied when a fixing force for fixing the endoscope-coupled part to the endoscope is defined as F 1 and a fixing force for the treatment tool-coupled part to the treatment tool is defined as F 2

F1>F2.

10. The endoscopic surgical device according to claim 1 , further comprising:

a first valve member that is provided in the endoscope insertion passage and secures airtightness within the body cavity; and

a second valve member that is provided in the treatment tool insertion passage and secures airtightness within the body cavity,

wherein following formulas are satisfied when a fixing force for fixing the endoscope-coupled part to the endoscope is defined as F 1 , a fixing force for fixing the treatment tool-coupled part to the treatment tool is defined as F 2 , and a frictional force that the endoscope receives from the first valve member when the endoscope moves forward and backward is defined as F 3

F 1 >F 3

F2>F3.

11. An endoscopic surgical device comprising:

an endoscope that is configured to observe an inside of a body cavity;

a treatment tool that is configured to inspect or treat an affected part within the body cavity; and

an overtube that is configured to guide the endoscope and the treatment tool he body cavity,

wherein the overtube includes

an overtube body that is configured to pass through a body wall and is configured to be inserted into the body cavity,

an endoscope insertion passage that is provided inside the overtube body and allows the endoscope to be inserted therethrough so as to be movable forward and backward,

a treatment tool insertion passage that is provided inside the overtube body and allows the treatment tool to be inserted therethrough so as to be movable forward and backward,

an interlocking member which is configured to be movable forward and backward inside the overtube body, has an endoscope-coupled part to be coupled to the endoscope inserted through the endoscope insertion passage and a treatment tool-coupled part to be coupled to the treatment tool inserted through the treatment tool insertion passage, and has a dead zone where the forward and backward movement of either one of the endoscope and the treatment tool does not interlock with the movement of the other, and a sensing zone where the forward and backward movement of either one of the endoscope and the treatment tool interlocks with the movement of the other,

a side surface opening that is formed to pass through a side wall of the overtube body, allows an inner cavity of the overtube body and the inside of the body cavity to communicate with each other when the overtube body is inserted into the body cavity, and sends a fluid into the body cavity through the inner cavity of the overtube body,

an inner needle that includes a first elongated shaft part inserted through the endoscope insertion passage and a second elongated shaft part inserted through the treatment tool insertion passage, and that is assembled in to the overtube body in a state where respective distal end parts of the first shaft part and the second shaft part are made to protrude from the overtube body when being inserted into the body cavity, and

a shutter member that is arranged inside the overtube body, is movable in engagement with the inner needle, and is movable between an open position where the side surface opening is open and a closed position where the side surface opening is closed.

12. The endoscopic surgical device according to claim 11 ,

wherein the inner needle includes a head part that links a base end of the first shaft part and a base end of the second shaft part, and a fixing mechanism that is provided at the head part and detachably fixes the head part to the overtube, and

wherein the shutter member is located at the closed position when the head part has been fixed to the overtube by the fixing mechanism.

13. An overtube comprising:

an overtube body that is configured to pass through a body wall and is configured to be is inserted into a body cavity;

an endoscope insertion passage that is provided inside the overtube body and allows an endoscope for observing the inside of the body cavity to be inserted therethrough so as to be movable forward and backward;

a treatment tool insertion passage that is provided inside the overtube body and allows a treatment tool for inspecting or treating an affected part within the body cavity to be inserted therethrough so as to be movable forward and backward;

an interlocking member which is configured to be movable forward and backward inside the overtube body, has an endoscope-coupled part to be coupled to the endoscope inserted through the endoscope insertion passage and a treatment tool-coupled part to be coupled to the treatment tool inserted through the treatment tool insertion passage, and has a dead zone where the forward and backward movement of either one of the endoscope and the treatment tool does not interlock with the movement of the other, and a sensing zone where the forward and backward movement of either one of the endoscope and the treatment tool interlocks with the movement of the other, and

a side surface opening that is formed to pass through a side wall of the overtube body, allows an inner cavity of the overtube body and the inside of the body cavity to communicate with each other when the overtube body is inserted into the body cavity, and sends a fluid into the body cavity through the inner cavity of the overtube body,

wherein the side surface opening is configured to be openable and closable by the forward and backward movement of the interlocking member.

14. The overtube according to claim 13 , further comprising:

an inner needle that includes a first elongated shaft part inserted through the endoscope insertion passage and a second elongated shaft part inserted through the treatment tool insertion passage, and that is assembled into the overtube body in a state where respective distal end parts of the first shaft part and the second shaft part are made to protrude from the overtube body when being inserted into the body cavity,

wherein the interlocking member is positioned at a position that faces the side surface opening in a state where the inner needle has been assembled into the overtube body, and the side surface opening is closed by one wall surface of the interlocking member.

15. The overtube according to claim 14 ,

wherein the first shaft part or the second shaft part is provided with an engagement part that engages with the interlocking member, and

wherein the interlocking member is positioned at a position that faces the side surface opening by the engagement part of the first shaft part or the second shaft part being engaged therewith, in a state where the inner needle has been assembled into the overtube body.

16. The overtube according to claim 15 ,

wherein the inner needle includes a head part that links a base end of the first shaft part and a base end of the second shaft part, and a fixing mechanism that is provided at the head part and detachably fixes the head part to the overtube, and

wherein the interlocking member is arranged at a position that faces the side surface opening when the head part has been fixed to the overtube by the fixing mechanism.

17. The overtube according to claim 15 ,

wherein the first shaft part or the second shaft part includes a smaller-diameter part that is arranged on a distal end side, and a larger-diameter part that is connected to a base end side of the smaller-diameter part,

wherein the engagement part is constituted by a stepped part formed at a boundary position between the smaller-diameter part and the larger-diameter part, and

wherein the interlocking member includes a hole that is larger than an external diameter of the smaller-diameter part and is smaller than an external diameter of the larger-diameter part, and an abutment part that is a peripheral part of the hole and against which the stepped part abuts.

18. The overtube according to claim 15 ,

wherein the engagement part includes a frictional engagement part that frictionally engages with the interlocking member.

19. The overtube according to claim 13 ,

wherein the side surface opening is provided on a distal end side of the overtube body, and is closed by one wall surface of the interlocking member when the interlocking member has moved to a foremost position of a movable range thereof.