Ligation device, ligation system, and storage medium

Abstract

Provided are a ligation device, a ligation system, and a storage medium, with which it is possible to ligate a body to be ligated with a thread by pulling the thread with a force of an appropriate magnitude. The ligation device is provided with: a gripping member that grips a portion of a thread wound around a body to be ligated and that moves in a direction away from the body to be ligated; a first motor that drives the gripping member; and a controller that controls the driving of the first motor. The controller drives the first motor so that the gripping member moves rearward in a state in which the gripping member grips the thread partially hooked on the body to be ligated (S109). The controller acquires a parameter correlated with a force at the time of pulling the thread by moving the gripping member rearward (S113). The controller determines whether to stop the movement of the gripping member on the basis of the temporal change rate of the force identified on the basis of the parameter (S115), and if it is determined to stop the gripping member (S115: YES), the controller stops the drive of the first motor (S117).

Description

Ligating device, ligating system, and storage medium

[0001] The present invention relates to a ligation device, a ligation system, and a storage medium for ligating an object to be ligated with a thread.

[0002] Ligation devices that ligate an object to be ligated with a thread have been proposed. The ligation device described in Patent Document 1 presses a loop of the thread against the object to be ligated while wrapping the thread around the object. The ligation device then tightens the loop to form a knot, thereby ligating the object to be ligated.

[0003] The magnitude of the force applied to the suture when tightening the loop is preferably adjusted so that the suture can properly ligate the target tissue. In response to this, for example, Patent Document 2 discloses a robot-assisted surgery system that uses a force sensor to measure the force applied to a surgical instrument operated by an operator and outputs a sound corresponding to the measurement result. The operator can perform surgery while recognizing the force applied to the surgical instrument based on the sound output from the robot-assisted surgery system.

[0004] Special table No. 8-252257 Publication No. 2013-533063

[0005] The optimal conditions for ligating the body to be ligated vary depending on the conditions at the time of ligation (such as the size and hardness of the body to be ligated, and the pressure inside the body to be ligated.) Therefore, even if the force pulling the suture is measured using the technology described in Patent Document 2, the optimal conditions for ligating the body to be ligated are unknown, and the ligation device is therefore unable to pull the suture with an appropriate amount of force to ligate the body to be ligated.

[0006] An object of the present invention is to provide a ligation device, a ligation system, and a storage medium that are capable of ligating an object to be ligated with a thread by pulling the thread with an appropriate amount of force.

[0007] A ligation device according to a first aspect of the present invention comprises a first gripping member that grips a portion of the suture wound around a body to be ligated and moves in a first direction away from the body to be ligated, a first motor that drives the first gripping member, and at least one controller that is electrically connected to the first motor and controls the driving of the first motor, wherein the controller drives the first motor so that the first gripping member moves in the first direction while the first gripping member is gripping the suture, a portion of which is hooked on the body to be ligated, acquires a parameter that is correlated with the force used when moving the first gripping member in the first direction to pull the suture, determines whether or not to stop the movement of the first gripping member based on the time rate of change of the force identified based on the acquired parameter, and stops driving the first motor when it is determined that the first gripping member should be stopped.

[0008] In a first aspect, the ligation device ligates the object to be ligated with the suture by moving the first gripping member gripping the suture in a first direction. Here, the drive conditions of the first gripping member for properly ligating the object to be ligated with the suture are related to the time rate of change of the force when pulling the suture. Therefore, the ligation device determines the timing to stop the movement of the first gripping member based on the time rate of change of the force when pulling the suture. This allows the ligation device to pull the suture with an appropriate amount of force, thereby properly ligating the object to be ligated with the suture.

[0009] A second aspect of the present invention provides a ligation system including a ligation device including a first gripping member that grips a portion of a suture wound around an object to be ligated and moves in a first direction away from the object to be ligated, a first motor that drives the first gripping member, and at least one controller that controls the drive of the first motor, wherein the controller drives the first motor to move the first gripping member in the first direction while the first gripping member is gripping the suture, a parameter that correlates with the force exerted when the first gripping member is moved in the first direction to pull the suture, determines whether to stop the movement of the first gripping member based on a time rate of change of the force determined based on the parameter, and stops the drive of the first motor if it is determined that the first gripping member should be stopped.

[0010] A third aspect of the present invention relates to a storage medium having stored therein a program executable by at least one controller, the program causing the controller to drive a first motor so that a first gripping member gripping a portion of a suture wound around an object to be ligated moves in a first direction away from the object to be ligated, to acquire a parameter correlated with a force exerted when the first gripping member is moved in the first direction to pull the suture, to determine whether or not to stop the movement of the first gripping member based on a time rate of change of the force determined based on the acquired parameter, and to stop driving the first motor if it is determined that the first gripping member should be stopped. According to the third aspect, it is possible to achieve an effect similar to that of the first aspect.

[0011] A perspective view of the ligation device 1 and a partially enlarged perspective view showing the state where the cartridge 7 has detached from the mounting portion 28. A cross-sectional view taken along line II-II of FIG. 1 as viewed from the arrow direction, and a partially enlarged cross-sectional view showing the state of the mounting portion 28 from which the cartridge 7 has detached. A cross-sectional view taken along line III-III of FIG. 1 as viewed from the arrow direction, and a partially enlarged cross-sectional view showing the state of the mounting portion 28 from which the cartridge 7 has detached. A cross-sectional view taken along line IV-IV of FIG. 1 as viewed from the arrow direction. A perspective view of the loop forming portion 2B. A perspective view of the cartridge 7. A right side view of the cartridge 7. A front view of the cartridge 7. A bottom view of the cartridge 7. A cross-sectional view taken along line X-X of FIG. 6 as viewed from the arrow direction. A cross-sectional view taken along line XI-XI of FIG. 7 as viewed from the arrow direction. A cross-sectional view taken along line XII-XII of FIG. 7 as viewed from the arrow direction. A perspective view of the gripping body 4, the pusher 5, and the drive unit 8. A rear view of the drive unit 8. A perspective view of the ligation gripping member 4A and the first drive mechanism 8A. A perspective view of the rearrangement gripping member 4B and the second drive mechanism 8B. A perspective view of the pusher 5 and the third drive mechanism 8C. A perspective view of the first rods 41, 43. A side view of the first rods 41, 43. A perspective view of the second rods 42, 44. A side view of the second rods 42, 44. A cross-sectional view taken along line XXII-XXII of FIG. 21 as viewed from the arrow direction. A perspective view of the first rods 41, 43 and the second rods 42, 44. A side view of the first rods 41, 43 and the second rods 42, 44 in the released state. A side view of the first rods 41, 43 and the second rods 42, 44 in the semi-gripping state. A side view of the first rods 41, 43 and the second rods 42, 44 in the fully-gripping state. A plan view of the tongue member 6. A perspective view of the tongue member 6. A block diagram showing the electrical configuration of the robot R and the ligation device 1. A flowchart showing the ligation process. A flowchart showing the ligation process, which is a continuation of FIG. 30. A flowchart showing the tightening process. A graph showing the current value, the first derivative value of the current value, and the second derivative value of the current value obtained from the motor driver Fb1. A view showing the initial state of the ligation process. A view showing the first step of the ligation process. A view showing the second step of the ligation process. A view showing the third step of the ligation process. A view showing the fourth step of the ligation process. A view showing the fifth step of the ligation process.1 is a diagram showing a sixth step of the ligating process; a diagram showing a seventh step of the ligating process; a diagram showing a ninth step of the ligating process; a diagram showing a tenth step of the ligating process; a diagram showing an eleventh step of the ligating process; a diagram showing a twelfth step of the ligating process; a diagram showing a thirteenth step of the ligating process; a diagram showing a state of the ligation target body S around which the thread T is wound; a diagram showing a fourteenth step of the ligating process; a diagram showing a state of the ligation target body S around which the thread T is wound; a diagram showing a fifteenth step of the ligating process; a diagram showing a sixteenth step of the ligating process; a diagram showing a seventeenth step of the ligating process; a diagram showing how the thread T1 moves along the reel member 73; a diagram showing how the thread T1 is wound around the reel member 73; a diagram showing an eighteenth step of the ligating process; a diagram showing a nineteenth step of the ligating process; a flowchart showing a rearrangement process; a diagram showing a first step of the rearrangement process; a diagram showing a second step of the rearrangement process. 10A to 10C are diagrams showing a third step of the rearrangement process, a fourth step of the rearrangement process, a fifth step of the rearrangement process, a sixth step of the rearrangement process, and a seventh step of the rearrangement process.

[0012] An embodiment of a ligation device 1 according to the present invention will be described with reference to the drawings. The referenced drawings are used to explain technical features that can be adopted by the present invention. The configurations of the device described are merely illustrative examples and are not intended to be limiting. The top, bottom, bottom left, top right, bottom right, and top left in Fig. 1 correspond to the top, bottom, front, back, left, and right of the ligation device 1, respectively.

[0013] <Overview of Ligation Device 1> The ligation device 1 is a device for ligating a body S to be ligated with a thread T. The body S to be ligated is, for example, a part of a living body, such as a blood vessel. The ligation device 1 is used by being connected to a surgical support robot R that performs surgery using minimally invasive techniques.

[0014] The ligation device 1 includes a main body 2A, a loop forming portion 2B, and a jaw member 3 shown in FIG. 1, a gripping body 4 and a pusher 5 shown in FIG. 13, a tongue member 6 shown in FIG. 27, and a drive unit 8 shown in FIG. 13.

[0015] <Main body 2A> As shown in Figures 1 to 3, the main body 2A has a cylindrical shape and extends in the front-to-rear direction. The jaw member 3, which will be described later, is supported at the front end of the main body 2A. The jaw member 3 is rotatable about a first axis C1 that extends in the up-down direction. The following description will be given assuming that the main body 2A and the jaw member 3 are arranged in a straight line in the front-to-rear direction.

[0016] 4, a plurality of insertion holes are formed inside the main body 2A. Specifically, a first hole 21, a second hole 22A, a third hole 22B, a fourth hole 23A, a fifth hole 23B, a sixth hole 24A, a seventh hole 24B, an eighth hole 25A, a ninth hole 25B, and a tenth hole 26 are formed inside the main body 2A.

[0017] The first hole 21 is disposed in the center of the main body 2A in the left-right direction. As shown in FIG. 2 , the first hole 21 includes an extension portion 21A, a first branch portion 21B, and a second branch portion 21C. The extension portion 21A extends rearward from the front end of the main body 2A. The first branch portion 21B extends rearward from the rear end of the extension portion 21A. The second branch portion 21C extends diagonally downward and rearward from the rear end of the extension portion 21A, then bends rearward and extends rearward again. The first hole 21 branches into the first branch portion 21B and the second branch portion 21C at the rear end of the extension portion 21A. A portion of the ligation grasping member 4A and a portion of the pusher 5 are inserted into the first branch portion 21B. A portion of the repositioning grasping member 4B is inserted into the second branch portion 21C.

[0018] The second hole 22A, the third hole 22B, the fourth hole 23A, the fifth hole 23B, the sixth hole 24A, the seventh hole 24B, the eighth hole 25A, the ninth hole 25B, and the tenth hole 26 shown in FIG. 4 extend in the front-to-rear direction.

[0019] The second hole 22A and the third hole 22B are arranged in the center of the main body 2A in the up-down direction. The second hole 22A is arranged to the right of the first hole 21. The third hole 22B is arranged to the left of the first hole 21. A third operating wire (not shown) is inserted through the second hole 22A and the third hole 22B. The fourth hole 23A is arranged to the right of the second branch portion 21C. The fifth hole 23B is arranged to the left of the second branch portion 21C. The loop-shaped rotating belt 230 shown in FIG. 2 is inserted through the fourth hole 23A and the fifth hole 23B.

[0020] The sixth hole 24A is located to the right of the second hole 22A. The seventh hole 24B is located to the left of the third hole 22B. A second operating wire (not shown) is inserted through the sixth hole 24A and the seventh hole 24B. In the main body 2A, the jaw member 3 rotates relative to the main body 2A in response to operation of the second operating wire.

[0021] The eighth hole 25A is located on the left side of the first branch portion 21B. The ninth hole 25B is located on the left side of the second branch portion 21C. The eighth hole 25A and the ninth hole 25B are aligned in the vertical direction. A fourth operating wire (not shown) is inserted through the eighth hole 25A and the ninth hole 25B. The tenth hole 26 is located on the right side of the second branch portion 21C and to the left of the fourth hole 23A. A first operating wire (not shown) is inserted through the tenth hole 26.

[0022] 2 and 3, the loop forming unit 2B is disposed inside the main body 2A, behind the jaw members 3. The loop forming unit 2B forms a loop in the yarn T in the extension portion 21A of the first hole 21. The loop forming unit 2B includes a first loop axis 46 and a second loop axis 56.

[0023] 5, the first loop shaft 46 includes a first support base 46A, a first separating base 46B, a second separating base 46C, a first separating wall 461B, a second separating wall 462B, a third separating wall 461C, a fourth separating wall 462C, and a first gear 46D. The second loop shaft 56 includes a second support base 56A, a third separating base 56B, a fourth separating wall 56C, a fifth separating wall 561B, a sixth separating wall 562B, a seventh separating wall 561C, an eighth separating wall 562C, and a second gear 56D.

[0024] The first support base 46A and the second support base 56A are circular plates and are perpendicular to the vertical direction. The first support base 46A and the second support base 56A are aligned in the front-to-rear direction. The first support base 46A is disposed behind the second support base 56A. The first support base 46A is rotatable about a fourth axis C4 that passes through the center and extends in the vertical direction. The second support base 56A is rotatable about a fifth axis C5 that passes through the center and extends in the vertical direction.

[0025] A first groove 463 is formed on the side of the first support base 46A. The third operating wire extends from the rear to the front of the first support base 46A, wraps around the first groove 463, changes direction, and extends rearward. A first gear 46D is provided on the underside of the first support base 46A. A second gear 56D is provided on the underside of the second support base 56A. The first gear 46D and the second gear 56D mesh with each other. In response to operation of the third operating wire, the first support base 46A and the second support base 56A rotate in unison.

[0026] When viewed from above, if the first support base 46A rotates clockwise, the second support base 56A rotates counterclockwise. Hereinafter, this rotation direction will be referred to as the "first rotation direction R1." When viewed from above, if the first support base 46A rotates counterclockwise, the second support base 56A rotates clockwise. Hereinafter, this rotation direction will be referred to as the "second rotation direction R2." In the following description, unless otherwise specified, the terms "clockwise direction" and "counterclockwise direction" refer to the rotation directions assumed when viewed from above.

[0027] The first and second spacing blocks 46B and 46C are provided on the upper surface of the first support block 46A. The first and second spacing blocks 46B and 46C are spaced apart in the radial direction about the fourth axis C4. A second groove 460A is formed between the first and second spacing blocks 46B and 46C. The third and fourth spacing blocks 56B and 56C are provided on the upper surface of the second support block 56A. The third and fourth spacing blocks 56B and 56C are spaced apart in the radial direction about the fifth axis C5. A third groove 560A is formed between the third and fourth spacing blocks 56B and 56C.

[0028] The first and second partition walls 461B and 462B protrude upward from the first partition base 46B. The first and second partition walls 461B and 462B are spaced apart in the circumferential direction about the fourth axis C4. A fourth groove 460B is formed between the first and second partition walls 461B and 462B. The third and fourth partition walls 461C and 462C protrude upward from the second partition base 46C. The third and fourth partition walls 461C and 462C are spaced apart in the circumferential direction about the fourth axis C4. A fifth groove 460C is formed between the third and fourth partition walls 461C and 462C. The upper ends of the first partition wall 461B, the second partition wall 462B, the third partition wall 461C, and the fourth partition wall 462C are inclined upward from the clockwise end to the opposite end.

[0029] The fifth partition wall 561B and the sixth partition wall 562B protrude upward from the third partition base 56B. The fifth partition wall 561B and the sixth partition wall 562B are spaced apart in the circumferential direction about the fifth axis C5. A sixth groove 560B is formed between the fifth partition wall 561B and the sixth partition wall 562B. The seventh partition wall 561C and the eighth partition wall 562C protrude upward from the fourth partition base 56C. The seventh partition wall 561C and the eighth partition wall 562C are spaced apart in the circumferential direction about the fifth axis C5. A seventh groove 560C is formed between the seventh partition wall 561C and the eighth partition wall 562C. The upper ends of the fifth partition wall 561B, the sixth partition wall 562B, the seventh partition wall 561C, and the eighth partition wall 562C are inclined upward from the end in the counterclockwise direction to the opposite end.

[0030] As shown in Fig. 5, when the first loop shaft 46 rotates and the second separating table 46C is positioned to the right of the first separating table 46B, the second loop shaft 56 rotates in conjunction with the first separating table 46B, and the fourth separating table 56C is positioned to the left of the third separating table 56B. Hereinafter, the rotation position shown in Fig. 5 will be referred to as the "first rotation position." The position where the first loop shaft 46 and the second loop shaft 56 are rotated 90 degrees in the first rotation direction R1 from the first rotation position will be referred to as the "second rotation position." The position where the first loop shaft 46 and the second loop shaft 56 are rotated 180 degrees from the first rotation position will be referred to as the "third rotation position."

[0031] When the first loop shaft 46 and the second loop shaft 56 are disposed in the first rotation position or the third rotation position, the second groove 460A and the third groove 560A extend in the front-rear direction, and the fourth groove 460B, the fifth groove 460C, the sixth groove 560B, and the seventh groove 560C extend in the left-right direction. When the first loop shaft 46 and the second loop shaft 56 are disposed in the second rotation position, the second groove 460A and the third groove 560A extend in the left-right direction, and the fourth groove 460B, the fifth groove 460C, the sixth groove 560B, and the seventh groove 560C extend in the front-rear direction.

[0032] The loop forming unit 2B can form the first loop P1 and the second loop P2 shown in FIG. 35 and the like by winding the yarn T around the first loop shaft 46 and the second loop shaft 56. The first loop P1 is formed on the first loop shaft 46, and the second loop P2 is formed on the second loop shaft 56. Furthermore, by rotating the first loop shaft 46 and the second loop shaft 56 with the first loop P1 and the second loop P2 formed, the loop forming unit 2B can remove the first loop P1 and the second loop P2 from the first loop shaft 46 and the second loop shaft 56 while maintaining the state in which the first loop P1 and the second loop P2 are formed on the yarn T.

[0033] 1, the jaw member 3 is provided at the front end of the main body 2A. The jaw member 3 includes a jaw main body 20A, a first jaw 3A, and a second jaw 3B.

[0034] The jaw body 20A has a cylindrical shape and extends in the front-to-rear direction. The diameter of the jaw body 20A is the same as the diameter of the main body 2A. The rear end of the jaw body 20A is rotatably supported by the main body 2A. A first jaw 3A and a second jaw 3B are provided at the front end of the jaw body 20A. The first jaw 3A and the second jaw 3B hold the body to be ligated S shown in FIG. 35 etc.

[0035] 1, the first jaw 3A extends forward from the front end of the main body 2A. The width of the first jaw 3A in the left-right direction is smaller than the width of the jaw main body 20A in the left-right direction.

[0036] The first jaw 3A and the jaw main body 20A have a mounting portion 28 to which a cartridge 7, described below, is attached. The portion of the mounting portion 28 that is provided on the jaw main body 20A is referred to as the first portion mounting portion 28A. The first portion mounting portion 28A is recessed downward from the upper surface of the jaw main body 20A. The portion of the mounting portion 28 that is provided on the first jaw 3A is referred to as the second portion mounting portion 32A. The second portion mounting portion 32A penetrates between the upper and lower surfaces of the first jaw 3A. The left-right width of the second portion mounting portion 32A is smaller than the left-right width of the first portion mounting portion 28A.

[0037] As shown in Figures 2 and 3, a pulley 27 is provided at the bottom of the first partial mounting portion 28A. The pulley 27 is plate-shaped and perpendicular to the vertical direction. A mounting hole 27A is formed in the center of the pulley 27. The mounting hole 27A has a regular hexagonal cross section and penetrates in the vertical direction. A protrusion 72B of the cartridge 7, which will be described later, is fitted into the mounting hole 27A. A rotating belt 230 is wound around the side of the pulley 27. The pulley 27 rotates in response to the rotation of the rotating belt 230. Hereinafter, the pulley 27 and the rotating belt 230 will be referred to as the "transmission mechanism 29."

[0038] 2, a first jaw through-hole 33 is formed near the front end of the first jaw 3A. The first jaw through-hole 33 passes through the first jaw 3A in the up-down direction. The side surface of the first jaw through-hole 33 is formed by the front surface of the cartridge 7 when attached to the attachment portion 28 and the side surface of the second partial attachment portion 32A.

[0039] 1 and 2, an eleventh hole 32B is formed in the jaw main body 20A and rearward of the first portion mounting portion 28A. The front end of the eleventh hole 32B communicates with the first portion mounting portion 28A. The eleventh hole 32B extends rearward from the portion communicating with the mounting portion 28A to the rear end of the jaw main body 20A. The rear end of the eleventh hole 32B is located forward of the front end of the extension portion 21A of the first hole 21 provided in the main body 2A.

[0040] The second jaw 3B extends forward from the front end of the main body 2A below the first jaw 3A, then bends diagonally upward and forward, and extends further. The left-right width of the second jaw 3B is smaller than the left-right width of the jaw main body 20A and is the same as that of the first jaw 3A.

[0041] The rear end of the second jaw 3B is rotatably supported on the front end of the main body 2A. A seventh axis C7 extends in the left-right direction along the rotation center of the second jaw 3B. In response to rotation about the seventh axis C7, the second jaw 3B moves between a close position (see FIGS. 1 and 2) in contact with the front end of the first jaw 3A and a distant position spaced downward from the front end of the first jaw 3A. The second jaw 3B moves between the close position and the distant position in response to operation of the fourth operating wire.

[0042] With the second jaw 3B positioned in the close position, a gap is formed between a portion of the first jaw 3A excluding the portion in contact with the second jaw 3B and a portion of the second jaw 3B excluding the portion in contact with the first jaw 3A. The object to be ligated S is held by the first jaw 3A and the second jaw 3B while being positioned in this gap. The region in which the object to be ligated S held by the first jaw 3A and the second jaw 3B is positioned is referred to as the "holding region Sp."

[0043] As shown in Fig. 2, a twelfth hole 31A is formed in the second jaw 3B. The twelfth hole 31A extends diagonally downward and rearward from the portion that contacts the first jaw 3A when the jaw is positioned in the close position, then bends rearward and extends rearward to the rear end of the second jaw 3B. The twelfth hole 31A penetrates the front end of the second jaw 3B in the up-down direction. The twelfth hole 31A is an example of a second-jaw through-hole.

[0044] A thirteenth hole 31B is formed in the jaw body 20A below the pulley 27 of the first partial mounting portion 28A. The thirteenth hole 31B extends rearward from the front end of the jaw body 20A. The front end of the thirteenth hole 31B is located rearward of the rear end of the twelfth hole 31A provided in the second jaw 3B. A tongue member 6 shown in FIG. 27, which will be described later, is located in the twelfth hole 31A and the thirteenth hole 31B.

[0045] <Cartridge 7> The cartridge 7 is detachably attached to the attachment portion 28 of the jaw member 3. As shown in Fig. 6, the cartridge 7 has a first partial body 7A and a second partial body 7B.

[0046] The first partial body 7A is shaped like a rectangular parallelepiped that is elongated in the front-to-rear direction. The second partial body 7B is rod-shaped and extends forward from near the upper end of the front surface 700F of the first partial body 7A. The left-to-right width of the second partial body 7B is smaller than the left-to-right width of the first partial body 7A. The up-to-down width of the second partial body 7B is smaller than the up-to-down width of the first partial body 7A. The top surfaces of the first partial body 7A and the second partial body 7B are arranged on the same plane. The first partial body 7A is attached to the first partial attachment portion 28A of the attachment portion 28 shown in FIG. 1. The second partial body 7B is attached to the second partial attachment portion 32A of the attachment portion 28 shown in FIG. 1.

[0047] A protruding portion 700P that protrudes downward is provided on a portion of the underside 700S of the first partial main body 7A near the front end. As shown in Fig. 7, a bobbin B is provided on the protruding portion 700P. A thread T is wound around the bobbin B. As shown in Fig. 2, the bobbin B is positioned rearward of the holding region Sp where the body S to be ligated is held by the first jaw 3A and the second jaw 3B. The bobbin B is supported rotatably about a third axis C3 that extends in the left-right direction.

[0048] As shown in Fig. 10, a 14th hole 7H is formed in protruding portion 700P below bobbin B. When cartridge 7 is attached to attachment portion 28 of jaw member 3, 14th hole 7H is located between 12th hole 31A of second jaw 3B and 13th hole 31B of jaw body 20A shown in Fig. 2. 12th hole 31A, 13th hole 31B, and 14th hole 7H are aligned in a straight line in the front-to-rear direction.

[0049] As shown in Fig. 6, the first partial main body 7A has a storage recess 71 extending downward from the upper surface 700U. The cross-sectional shape of the storage recess 71 is circular. As shown in Fig. 10 and Fig. 11, the storage recess 71 has a collection section 71A and a first storage section 71B, each of which has a different inner diameter.

[0050] The first storage section 71B is located below the collection section 71A. The inner diameter of the first storage section 71B is uniform in the vertical direction. The inner diameter of the first storage section 71B is larger than the inner diameter of the collection section 71A. The side surface 70B of the first storage section 71B extends along the vertical direction. A groove 711 is formed on the side surface 70B, extending spirally around an axis that passes through the center of the storage recess 71 and extends in the vertical direction. A plurality of protrusions 710 that protrude inward are formed in the area sandwiched between the grooves 711 in the vertical direction. The protrusion direction of the protrusions 710 is perpendicular to the vertical direction.

[0051] A transmission through-hole 71C communicating with the lower surface 700S of the first partial main body 7A is formed in the bottom surface 70C of the accommodation recess 71.

[0052] A reel member 73 is housed in the housing recess 71. The reel member 73 extends downward from the upper end of the collection section 71A to the lower end of the first housing section 71B. The reel member 73 is a double spring including a first coil spring 73A and a second coil spring 73B.

[0053] The first coil spring 73A and the second coil spring 73B have the same diameter. The first coil spring 73A and the second coil spring 73B have the same diameter in the vertical direction. The centers of the first coil spring 73A and the second coil spring 73B coincide at the position of the second axis C2. The second axis C2 extends in the vertical direction. The first coil spring 73A and the second coil spring 73B have wires 730. The wires 730 of the first coil spring 73A are arranged at equal intervals in the vertical direction. The wires 730 of the second coil spring 73B are arranged at equal intervals in the vertical direction. The wires 730 of the first coil spring 73A and the second coil spring 73B are arranged alternately in the vertical direction. The intervals in the vertical direction between the wires 730 of the first coil spring 73A and the second coil spring 73B are uniform. The wire 730 is inclined with respect to the direction in which the second axis C2 extends.

[0054] The diameters of the first coil spring 73A and the second coil spring 73B are the same as the inner diameter of the collection section 71A and smaller than the inner diameter of the first storage section 71B. The reel member 73 contacts the inner wall 70A that forms the collection section 71A. The reel member 73 and the side surface 70B of the first storage section 71B are spaced apart in the radial direction about the second axis C2.

[0055] The rotating body 72 is connected to the lower end of the reel member 73. The rotating body 72 has a support plate 72A and a protrusion 72B.

[0056] The support plate 72A is a circular plate that is perpendicular to the vertical direction. The lower surface of the support plate 72A near the peripheral edge contacts the bottom surface 70C of the accommodation recess 71 from above. The lower end of the reel member 73 is connected to the upper surface of the support plate 72A.

[0057] The protrusion 72B protrudes downward from the lower surface of the support plate 72A. In other words, the protrusion 72B protrudes in the opposite direction from the reel member 73 across the support plate 72A in the vertical direction. As shown in FIG. 9, the shape of the protrusion 72B is a hexagonal prism. The protrusion 72B is inserted into a transmission through-hole 71C provided in the bottom surface 70C of the accommodating recess 71. As shown in FIG. 7, the protrusion 72B protrudes downward from the lower surface 700S of the first partial main body 7A.

[0058] The rotating body 72 is rotatably supported on the bottom surface 70C of the accommodation recess 71. The rotating body 72 rotates about a sixth axis C6 extending in the vertical direction. As shown in Figure 10, the position of the sixth axis C6 coincides with the position of the second axis C2 passing through the center of the reel member 73.

[0059] The protrusion 72B fits into the mounting hole 27A of the pulley 27 shown in Fig. 3 when the cartridge 7 is mounted on the mounting portion 28 of the jaw member 3 shown in Fig. 2. When the pulley 27 rotates in response to the rotation of the rotary belt 230, the rotating body 72 rotates about the sixth axis C6. In addition, as the rotating body 72 rotates, the reel member 73 connected to the support plate 72A also rotates about the second axis C2.

[0060] As shown in FIGS. 6 and 8, the first partial main body 7A is provided with a first communication hole 76A, a second communication hole 76B, and a third communication hole 76C.

[0061] As shown in FIG. 6 , the first communication hole 76A extends forward from the rear surface 700B of the first partial main body 7A and communicates with the storage recess 71. The first communication hole 76A is a rectangular hole that is long in the vertical direction. A first circular portion 761 with curved sides is provided below the upper end of the first communication hole 76A. The left-right width of the first circular portion 761 is greater than the left-right width of the portion of the first communication hole 76A excluding the first circular portion 761. As shown in FIG. 10 , the first circular portion 761 connects to the inner wall 70A of the collection section 71A of the storage recess 71.

[0062] As shown in FIG. 8 , the second communication hole 76B extends rearward from the front surface 700F of the first partial main body 7A and communicates with the storage recess 71. The second communication hole 76B is a rectangular hole that is long in the vertical direction. A second circular portion 762 with curved sides is provided below the upper end of the second communication hole 76B. The left-right width of the second circular portion 762 is greater than the left-right width of the portion of the second communication hole 76B excluding the second circular portion 762. As shown in FIG. 10 , the second circular portion 762 connects to the inner wall 70A of the collection section 71A of the storage recess 71.

[0063] The first communication hole 76A and the second communication hole 76B are aligned in the front-rear direction. The first circular portion 761 of the first communication hole 76A and the second circular portion 762 of the second communication hole 76B are aligned in a straight line in the front-rear direction. As shown in FIG. 11 , the first communication hole 76A and the second communication hole 76B are positioned so as to overlap with the second axis C2 and the sixth axis C6 in the front-rear direction.

[0064] As shown in FIG. 6, the third communication hole 76C extends downward from the upper surface 700U of the first partial main body 7A and communicates with the second communication hole 76B.

[0065] As shown in Figures 10 and 12, a winding yarn cutter 77 is provided in front of the reel member 73 and behind the bobbin B. The winding yarn cutter 77 is plate-shaped and perpendicular to the front-to-rear direction. The winding yarn cutter 77 extends rightward from the left end of the first partial main body 7A. The winding yarn cutter 77 overlaps with the reel member 73 in the left-to-right direction. A blade 77A of the winding yarn cutter 77 protrudes toward the portion of the storage recess 71 that communicates with the second communication hole 76B. The blade 77A extends in the up-down direction. As shown in Figure 11, the blade 77A is located leftward of the second axis C2 and the sixth axis C6 in the left-to-right direction.

[0066] 8 and 9 , the second partial main body 7B has an upper plate 78U, a right plate 78R, and a left plate 78L. The upper plate 78U is perpendicular to the up-down direction. The right plate 78R extends downward from the right end of the upper plate 78U. The left plate 78L extends downward from the left end of the upper plate 78U. A portion of an area 780 surrounded by the upper plate 78U, right plate 78R, and left plate 78L overlaps in the front-to-rear direction with the first circular portion 761 of the first communicating hole 76A and the second circular portion 762 of the second communicating hole 76B.

[0067] A gripping suture cutter 79 is provided near the front end of the upper plate 78U of the second partial body 7B. The gripping suture cutter 79 cuts the suture gripped by the ligature gripping member 4A. As shown in FIG. 2, when the cartridge 7 is attached to the jaw members 3, the gripping suture cutter 79 is located rearward of the first jaw through-hole 33 of the first jaw 3A. As shown in FIGS. 9 and 10, the blade 79A of the gripping suture cutter 79 protrudes toward an area 780 surrounded by the upper plate 78U, right plate 78R, and left plate 78L.

[0068] <Gripping body 4> At least a portion of the gripping body 4 is disposed within the main body 2A. The gripping body 4 is movable in the front-rear direction relative to the main body 2A. The gripping body 4 grips the suture T and moves rearward, thereby drawing the suture T into the main body 2A. As shown in FIG. 13 , the gripping body 4 includes a ligating gripping member 4A and a rearrangement gripping member 4B. The ligating gripping member 4A and the rearrangement gripping member 4B have the same shape. As shown in FIG. 14 , the ligating gripping member 4A is disposed above the rearrangement gripping member 4B. The ligating gripping member 4A is disposed inside a pusher 5, which will be described later.

[0069] As shown in Fig. 15, the ligation grasping member 4A has a first rod 41 and a second rod 42. The first rod 41 has a cylindrical shape and extends in the front-to-rear direction. The second rod 42 is disposed in a through hole within the first rod 41. The second rod 42 has a rod shape, more specifically, a cylindrical shape, and extends in the front-to-rear direction. As shown in Fig. 16, the repositioning grasping member 4B has a first rod 43 and a second rod 44. The first rod 43 and the second rod 44 correspond to the first rod 41 and the second rod 42 of the ligation grasping member 4A shown in Fig. 15. Details of the first rods 41, 43 and the second rods 42, 44 will be described later.

[0070] The ligation grasping member 4A is movable in the forward and backward directions along the extension portion 21A and the first branch portion 21B of the first hole 21 of the main body 2A shown in Figure 2, the eleventh hole 32B of the jaw main body 20A, and the first circular portion 761 of the first communicating hole 76A of the cartridge 7 shown in Figure 10, the second circular portion 762 of the second communicating hole 76B, and the recovery portion 71A of the storage recess 71.

[0071] The rearrangement gripping member 4B is movable in the front-rear direction along the extension portion 21A and the second branch portion 21C of the first hole 21 of the main body 2A shown in Fig. 2, the eleventh hole 32B of the jaw main body 20A, and the first circular portion 761 of the first communication hole 76A of the cartridge 7 shown in Fig. 10, the second circular portion 762 of the second communication hole 76B, and the recovery portion 71A of the storage recess 71. Hereinafter, the trajectory that the rearrangement gripping member 4B passes through when it moves as shown in Fig. 2 will be referred to as a "movement trajectory U."

[0072] 2 and 10, the movement locus U intersects with the reel member 73 disposed in the accommodating recess 71 of the cartridge 7. The first accommodating portion 71B of the accommodating recess 71 of the cartridge 7 is spaced downward from the movement locus U. The blade 79A of the gripping thread cutter 79 of the cartridge 7 is disposed opposite the second jaw 3B across the movement locus U in the up-down direction. The blade 79A protrudes toward the movement locus U.

[0073] <First rods 41, 43 and second rods 42, 44> The first rods 41, 43 have the same configuration. The second rods 42, 44 have the same configuration. In the following, the first rod 41 and the second rod 42 will be described as an example, and a description of the first rod 43 and the second rod 44 will be omitted.

[0074] 18 and 19, the first rod 41 has a cylindrical body 45. An eighth axis C8 passing through the center of the cylindrical body 45 extends in the front-rear direction.

[0075] A first notch 40 is provided in the front end 45F of the cylindrical body 45. The first notch 40 has a first one-side notch 461 and a first other-side notch 462. The first one-side notch 461 and the first other-side notch 462 are each recessed portions formed in the front end 45F and extend linearly rearward. The first one-side notch 461 and the first other-side notch 462 face each other in a direction perpendicular to the eighth axis C8. The widths of the first one-side notch 461 and the first other-side notch 462 at their connection portions with the front end 45F increase toward the front. As shown in FIG. 18 , the thickness of the cylindrical body 45 is denoted as "D1." The thickness D1 is greater than the thickness of the thread T.

[0076] As shown in Figures 20 and 21, the second rod 42 has a cylindrical body 47. A ninth axis C9 passing through the center of the cylindrical body 47 extends in the front-rear direction. The diameter of the cylindrical body 47 is the same as the inner diameter of the cylindrical body 45 of the first rod 41, 43. A second notch 48 is provided in the front end portion 47F of the cylindrical body 47. The second notch 48 has a first partial notch 480 and a second partial notch 481.

[0077] The first partial notch 480 is a recess formed in the front end portion 47F and extends linearly rearward. The first partial notch 480 is connected in a direction perpendicular to the ninth axis C9. The width of the first partial notch 480 at the connection portion with the front end portion 47F increases toward the front. The length of the first partial notch 480 in the front-rear direction is equal to the length of the first notch 40 of the first rod 41, 43 in the front-rear direction.

[0078] 21 and 22 , the second partial cutout 481 is provided at the rear end of the first partial cutout 480. The second partial cutout 481 has a first notch 481A and a second notch 481B. The first notch 481A and the second notch 481B face each other in a direction perpendicular to the ninth axis C9. The first notch 481A and the second notch 481B each extend clockwise from the rear end of the first partial cutout 480 along the circumferential direction centered on the ninth axis C9 as viewed from the front.

[0079] 23 , the second rod 42 is disposed inside the first rod 41. The front end 45F of the first rod 41 and the front end 47F of the second rod 42 are positioned in the front-to-rear direction. The eighth axis C8 of the first rod 41 and the ninth axis C9 of the second rod 42 are positioned in the same direction. The second rod 42 is rotatable about the ninth axis C9 relative to the first rod 41.

[0080] The extending direction of the first notch 40 of the first rod 41 coincides with the extending direction of the first partial notch 480 of the second rod 42. On the other hand, the extending direction of the first notch 40 of the first rod 41 is perpendicular to the extending direction of the second partial notch 481 of the second rod 42.

[0081] 24, 25, and 26 differ in the positional relationship between the first rod 41 and the second rod 42. The state shown in Fig. 24 is called the "released state." The state shown in Fig. 25 is called the "half-gripped state." The state shown in Fig. 26 is called the "fully-gripped state."

[0082] 24 , the first notch 40 of the first rod 41 and the first partial notch 480 of the second rod 42 overlap in the radial direction centered on the eighth axis C8 and the ninth axis C9. In the released state, the thread T can be inserted into the first notch 40 and the first partial notch 480, and the thread T can be removed from the first notch 40 and the first partial notch 480.

[0083] The semi-gripped state shown in Fig. 25 indicates a state in which the second rod 42 has been rotated approximately 45 degrees counterclockwise as viewed from the front from the released state shown in Fig. 24. In this state, the first notch 40 of the first rod 41 and a portion of the second partial notch 481 of the second rod 42 overlap in the radial direction centered on the eighth axis C8 and the ninth axis C9. The first partial notch 480 of the second rod 42 is covered by the cylindrical body 45 of the first rod 41.

[0084] After the thread T is inserted into the first notch 40 and the first partial notch 480 in the released state, when the state changes from the released state to the semi-held state, the thread T is positioned at the bottom of the first notch 40 of the first rod 41 and the second partial notch 481 of the second rod 42. The thread T is covered from the front by a portion of the second rod 42, and therefore cannot be detached from the first rod 41 and the second rod 42. Note that in the semi-held state, the cross-sectional area of ​​the region formed by the bottom of the first notch 40 of the first rod 41 and the second partial notch 481 of the second rod 42 is larger than the cross-sectional area of ​​the thread T. Therefore, the thread T is movable relative to the first rod 41 and the second rod 42.

[0085] The fully gripped state shown in Figure 26 indicates a state in which the second rod 42 has been rotated approximately 45 degrees counterclockwise as viewed from the front from the semi-gripped state shown in Figure 25. In this state, the bottom of the first notch 40 of the first rod 41 and a part of the tip of the second partial notch 481 of the second rod 42 overlap in the radial direction centered on the eighth axis C8 and the ninth axis C9. Note that the first partial notch 480 of the second rod 42 and the part of the second partial notch 481 excluding their tip portions are covered by the cylindrical body 45 of the first rod 41.

[0086] When the state changes from the open state to the fully gripped state after the thread T has been inserted into the first notch 40 and the first partial notch 480 in the released state, the thread T is gripped by the tip ends of the first notch 40 and the second partial notch 481. Therefore, the thread T becomes immovable relative to the first rod 41 and the second rod 42.

[0087] <Pusher 5> The pusher 5 shown in Fig. 17 is at least partially disposed within the main body 2A. The pusher 5 is movable in the front-rear direction relative to the main body 2A. By moving forward, the pusher 5 pushes the first loop P1 and the second loop P2 of the yarn T formed in the loop forming section 2B forward from the main body 2A.

[0088] The pusher 5 has a cylindrical shape and extends in the front-rear direction. The ligation grasper member 4A shown in Fig. 15 is disposed inside the pusher 5. A tenth axis C10 passing through the center of the pusher 5 coincides with the eighth axis C8 and the ninth axis C9 passing through the center of the ligation grasper member 4A. A front end 51 of the pusher 5 is inclined with respect to a plane perpendicular to the tenth axis C10.

[0089] The pusher 5 is movable in the front-rear direction along the extension portion 21A and the first branch portion 21B of the first hole 21 of the main body 2A shown in Fig. 2, the eleventh hole 32B of the jaw main body 20A, and the first circular portion 761 of the first communicating hole 76A of the cartridge 7 shown in Fig. 10, the second circular portion 762 of the second communicating hole 76B, and the recovery portion 71A of the storage recess 71. In addition, the pusher 5 is movable in the front-rear direction relative to the ligation grasping member 4A arranged therein.

[0090] <Tongue member 6> The tongue member 6 is disposed inside the jaw member 3. The tongue member 6 shown in FIG. 27 moves in the front-rear and up-down directions. The tongue member 6 passes the yarn T unwound from the bobbin B through the twelfth hole 31A of the second jaw 3B of the jaw member 3 shown in FIG. 2 and guides the yarn T toward the first jaw through-hole 33 of the first jaw 3A. The movement direction of the tongue member 6 at this time is defined as the "first movement direction Y1." The direction opposite to the first movement direction Y1 is referred to as the "second movement direction Y2." In FIG. 27, the upward direction corresponds to the first movement direction Y1, and the downward direction corresponds to the second movement direction Y2. The direction extending along the first movement direction Y1 and the second movement direction Y2 is referred to as the "extension direction Y."

[0091] The tongue member 6 has a flexible plate body 60. The shape of the plate body 60 is a rectangle that is long in the extension direction Y and perpendicular to the up-down direction. The base of the tongue member 6, i.e., the upstream end 60B, which is the upstream end of the plate body 60 in the first movement direction Y1, extends in the left-right direction. A plurality of round holes 60H are formed in the portion of the plate body 60 between the center in the extension direction and the upstream end 60B. The left end 60L and the right end 60R of the plate body 60 each extend in the extension direction Y. The left end 60L has a left curved portion 601 at its downstream end in the first movement direction Y1. The right end 60R has a right curved portion 602 at its downstream end in the first movement direction Y1.

[0092] A first inclined portion 61, a second inclined portion 62, a slit 63, and a capture portion 64 are formed at the tip of the tongue member 6, i.e., the downstream end in the first moving direction Y1 of the plate body 60.

[0093] The first inclined portion 61 extends linearly from the left curved portion 601 at the left end 60L to the right and upstream in the first movement direction Y1. The right end of the first inclined portion 61 is located to the right of the center position Qc of the plate body 60 in the left-right direction. A virtual line Q1 extending along the first inclined portion 61 is defined. The direction extending along the virtual line Q1 intersects with the extension direction Y.

[0094] A first curved portion 603 is connected to the right end of the first inclined portion 61. The first curved portion 603 curves from the end connected to the first inclined portion 61 to the opposite end, upstream in the first movement direction Y1, and further extends while curving leftward.

[0095] The second inclined portion 62 extends linearly from the right curved portion 602 at the right end 60R to the left and upstream in the first moving direction Y1. The left end of the second inclined portion 62 is located near the center position Qc of the plate body 60. The second inclined portion 62 intersects with the imaginary line Q1. A imaginary line Q2 extending along the second inclined portion 62 is defined. The direction extending along the imaginary line Q2 intersects with the drawing direction Y and the imaginary line Q1. A portion of the second inclined portion 62 faces the first curved portion 603 upstream in the first moving direction Y1. The distance between the second inclined portion 62 and the first curved portion 603 is denoted as "D2." The distance D2 is smaller than the thickness of the yarn T.

[0096] The slit 63 connects to the upstream end of the second inclined portion 62 in the first moving direction Y1. The slit 63 extends from the connecting portion with the second inclined portion 62 toward the upstream side in the first moving direction Y1 along the drawing direction Y. The left-right position of the slit 63 coincides with the center position Qc of the plate body 60. The spacing between the slits 63 is denoted as "D3." The spacing D3 is smaller than the thickness of the yarn T. The spacing D3 is smaller than the spacing D2.

[0097] The capturing portion 64 is connected to the end of the first curved portion 603 opposite to the end connected to the first inclined portion 61. The capturing portion 64 is recessed downstream in the first movement direction Y1. The capturing portion 64 is positioned downstream in the first movement direction Y1 with respect to the slit 63. An opening 604 is formed at the upstream end of the capturing portion 64 in the first movement direction Y1. The opening 604 opens upstream in the first movement direction Y1. The width of the opening 604 is referred to as "D4". The width D4 is greater than the spacing D3 of the slit 63.

[0098] The portion of the plate body 60 near the downstream end in the first moving direction Y1, where the first inclined portion 61, the second inclined portion 62, the slit 63, and the capture portion 64 are provided, is referred to as the "downstream end portion 60F."

[0099] A first operating wire is connected to a plurality of round holes 60H in the tongue member 6. The tongue member 6 moves in a first movement direction Y1 or a second movement direction Y2 in response to an operation of the first operating wire. The tongue member 6 is movable along the thirteenth hole 31B of the jaw body 20A shown in FIG. 2, the fourteenth hole 7H of the cartridge 7 shown in FIG. 10, and the twelfth hole 31A of the second jaw 3B shown in FIG. 2.

[0100] When the tongue member 6 moves in the first movement direction Y1 while the second jaw 3B is in the close position, the plate body 60 bends as shown in Fig. 28. The downstream end 60F of the plate body 60 protrudes from the tip of the second jaw 3B shown in Fig. 2 and moves toward the first jaw through-hole 33 of the first jaw 3A. The downstream end 60F of the plate body 60 is inserted into the first jaw through-hole 33 of the first jaw 3A.

[0101] When the tongue member 6 has moved the furthest in the first movement direction Y1, the downstream end 60F of the plate body 60 faces rearward. As shown in Figure 28, the forward-most portion of the plate body 60 is referred to as the "upstream end Q3." The upstream end Q3 is located forward of the downstream-most portion of the plate body 60 in the first movement direction Y1, i.e., the downstream end 60F.

[0102] Hereinafter, the position of the tongue member 6 that has moved the furthest in the first movement direction Y1 will be referred to as the "protruding position." The position of the tongue member 6 that has moved the furthest in the second movement direction Y2 will be referred to as the "retracted position." When the tongue member 6 is positioned in the retracted position, the plate body 60 extends linearly in the front-to-rear direction. In addition, the downstream end 60F of the plate body 60 is located rearward of the 14th hole 7H of the cartridge 7.

[0103] <Robot connection part 9> As shown in Fig. 1 , the robot connection part 9 covers the rear end part of the main body 2A. The robot connection part 9 has a cylindrical shape. The main body 2A passes rearward past the front end part of a side surface 91 of the robot connection part 9 and extends to the rear end part of the side surface 91. The gripper 4 and the pusher 5 pass through the main body 2A and extend rearward beyond the rear end part of the side surface 91.

[0104] A disk Rr of the robot R is connected to the upper end of the robot connection part 9. A plurality of robot motors MR built into the robot R are connected to the disk Rr. The rotation axes of the plurality of robot motors MR extend into the robot connection part 9. The robot R operates the first operation wire, the second operation wire, the third operation wire, the fourth operation wire, and the rotating belt 230 by rotating the plurality of robot motors MR.

[0105] <Drive unit 8> As shown in Fig. 1, the drive unit 8 is connected to the rear end of the side surface 91 of the robot connection part 9. The drive unit 8 has a cylindrical case 804. The case 804 houses the first drive mechanism 8A, second drive mechanism 8B, and third drive mechanism 8C shown in Figs. 13 to 17, and the first motor Ma1, first auxiliary motor Ma2, second motor Mb1, second auxiliary motor Mb2, third motor Mc1, and third auxiliary motor Mc2 shown in Fig. 29.

[0106] The first drive mechanism 8A shown in Fig. 15 moves the first rod 41 and the second rod 42 of the ligation grasping member 4A in the front-rear direction and rotates the second rod 42. The second drive mechanism 8B shown in Fig. 16 moves the first rod 43 and the second rod 44 of the rearrangement grasping member 4B in the front-rear direction and rotates the second rod 44. The third drive mechanism 8C shown in Fig. 17 moves the pusher 5 in the front-rear direction and rotates it.

[0107] <First drive mechanism 8A> As shown in FIG. 15, the first drive mechanism 8A has a first screw shaft Xa1, a first auxiliary shaft Xa2, a first grip support portion 80A, as well as a first motor Ma1 and a first auxiliary motor Ma2 shown in FIG. 29.

[0108] The first screw shaft Xa1 has a rod shape with a circular cross section. A male thread is formed on the side surface of the first screw shaft Xa1. The male thread extends spirally in the front-to-rear direction. The first screw shaft Xa1 is disposed diagonally downward to the right with respect to the first auxiliary shaft Xa2 and extends parallel to the first auxiliary shaft Xa2. The first auxiliary shaft Xa2 is a D-cut shaft with a D-shaped cross section. The first screw shaft Xa1 rotates when the first motor Ma1 is driven. The first auxiliary shaft Xa2 rotates when the first auxiliary motor Ma2 is driven.

[0109] The first gripping support portion 80A supports the first rod 41 and the second rod 42. The first gripping support portion 80A has a support base 81A, a first main gear 81B, and a first follower gear 81C.

[0110] The support base 81A supports the first rod 41, the first main gear 81B, and the first driven gear 81C. The support base 81A has a first through hole 811, a second through hole 812, and a third through hole 813. A female thread is formed on the inner surface of the first through hole 811. The female thread extends spirally in the front-to-rear direction. A first screw shaft Xa1 is inserted into the first through hole 811. The male thread of the first screw shaft Xa1 and the female thread of the first through hole 811 mesh with each other. A first auxiliary shaft Xa2 is inserted into the second through hole 812. The rear end of the first rod 41 is connected to the periphery of the third through hole 813 and to the front surface of the support base 81A.

[0111] The first main gear 81B is a spur gear with teeth provided only on approximately half of its circumferential area. The rotation axis of the first main gear 81B extends in the front-rear direction. A gear through-hole 81H with a D-shaped cross section is formed in the center of the first main gear 81B. The second through-hole 812 and the gear through-hole 81H are aligned in a straight line in the front-rear direction. The first auxiliary shaft Xa2 is inserted through the gear through-hole 81H. The first main gear 81B is movable in the front-rear direction relative to the first auxiliary shaft Xa2. The cross-sectional shape of the first auxiliary shaft Xa2 is also D-shaped. Therefore, the first main gear 81B rotates in response to the rotation of the first auxiliary shaft Xa2.

[0112] The first slave gear 81C is a spur gear. The rotation axis of the first slave gear 81C extends in the front-to-rear direction. The first slave gear 81C is provided at the rear end of the second rod 42. The second rod 42 extends forward from the first slave gear 81C. The second rod 42 passes through the third through-hole 813 and is inserted into the through-hole of the first rod 41. The first slave gear 81C meshes with the first main gear 81B. The first slave gear 81C rotates in accordance with the rotation of the first main gear 81B.

[0113] <Operation of First Drive Mechanism 8A> When the ligation device 1 moves the first rod 41 and the second rod 42 of the ligation grasping member 4A in the front-rear direction, the ligation device 1 drives the first motor Ma1 to rotate the first screw shaft Xa1. The first through-hole 811 receives a forward or rearward force in response to the rotation of the first screw shaft Xa1, and moves in the front-rear direction. In this case, the support base 81A in which the first through-hole 811 is formed moves in the front-rear direction in response to the movement of the first through-hole 811. The ligation grasping member 4A moves in the front-rear direction together with the first rod 41 and the second rod 42.

[0114] Furthermore, when rotating the second rod 42 relative to the first rod 41 of the ligation grasping member 4A, the ligation device 1 drives the first auxiliary motor Ma2 to rotate the first auxiliary shaft Xa2. In response to the rotation of the first auxiliary shaft Xa2, the first main gear 81B and the first driven gear 81C rotate. In response to the rotation of the first driven gear 81C, the second rod 42 also rotates. As a result, the second rod 42 rotates relative to the first rod 41 in the ligation grasping member 4A.

[0115] As described above, the first drive mechanism 8A moves the first rod 41 and the second rod 42 of the ligation grasping member 4A together in the front-to-rear direction in response to rotation of the first screw shaft Xa1 by driving the first motor Ma1. Furthermore, the first drive mechanism 8A rotates the second rod 42 relative to the first rod 41 in response to rotation of the first auxiliary shaft Xa2 by driving the first auxiliary motor Ma2.

[0116] <Second drive mechanism 8B> As shown in Figure 16, the second drive mechanism 8B has a second screw shaft Xb1, a second auxiliary shaft Xb2, a second grip support portion 80B, as well as a second motor Mb1 and a second auxiliary motor Mb2 shown in Figure 29.

[0117] The second screw shaft Xb1 has a rod shape with a circular cross section. A male thread is formed on the side surface of the second screw shaft Xb1. The male thread extends spirally in the front-to-rear direction. The second screw shaft Xb1 is disposed to the right of the second auxiliary shaft Xb2 and extends parallel to the second screw shaft Xb1. The second auxiliary shaft Xb2 is a D-cut shaft with a D-shaped cross section. The second screw shaft Xb1 is rotated by being driven by the second motor Mb1. The second auxiliary shaft Xb2 is rotated by being driven by the second auxiliary motor Mb2.

[0118] The second gripping support portion 80B supports the first rod 43 and the second rod 44. The configuration of the second gripping support portion 80B is the same as that of the first gripping support portion 80A shown in FIG.

[0119] The second grip support part 80B has a support base 82A, a first main gear 82B, and a first slave gear 82C. The support base 82A, the first main gear 82B, and the first slave gear 82C correspond to the support base 81A, the first main gear 81B, and the first slave gear 81C of the first grip support part 80A shown in Fig. 15. A first through hole 821, a second through hole 822, and a third through hole 823 formed in the support base 82A correspond to the first through hole 811, the second through hole 812, and the third through hole 813 formed in the support base 81A shown in Fig. 15, respectively.

[0120] The second screw shaft Xb1 is inserted through the first through hole 821. The male thread of the second screw shaft Xb1 meshes with the female thread of the first through hole 821. The second auxiliary shaft Xb2 is inserted through the second through hole 822. The rear end of the first rod 43 is connected to the periphery of the third through hole 823 and to the front surface of the support base 82A.

[0121] The second through-hole 822 and the gear through-hole 82H of the first main gear 82B are aligned in a straight line in the front-to-rear direction. The second auxiliary shaft Xb2 is inserted through the gear through-hole 82H. The first main gear 82B is movable in the front-to-rear direction relative to the second auxiliary shaft Xb2. The first main gear 82B rotates in response to the rotation of the second auxiliary shaft Xb2.

[0122] The first slave gear 82C is provided at the rear end of the second rod 44. The second rod 44 extends forward from the first slave gear 82C. The second rod 44 passes through the third through-hole 823 and is inserted into the through-hole of the first rod 43. The first slave gear 82C meshes with the first main gear 82B. The first slave gear 82C rotates in response to the rotation of the first main gear 82B.

[0123] <Operation of the Second Drive Mechanism 8B> The operation of the second drive mechanism 8B when moving the first rod 43 and the second rod 44 of the rearrangement gripping member 4B in the front-to-rear direction is the same as the operation of the first drive mechanism 8A shown in Fig. 15. The second drive mechanism 8B moves the first rod 43 and the second rod 44 of the rearrangement gripping member 4B together in the front-to-rear direction in response to rotation of the second screw shaft Xb1 by driving of the second motor Mb1. Furthermore, the second drive mechanism 8B rotates the second rod 44 relative to the first rod 43 in response to rotation of the second auxiliary shaft Xb2 by driving of the second auxiliary motor Mb2.

[0124] <Third drive mechanism 8C> As shown in Figure 17, the third drive mechanism 8C has a third screw shaft Xc1, a third auxiliary shaft Xc2, and a pusher support portion 80C, as well as a third motor Mc1 and a third auxiliary motor Mc2 shown in Figure 29.

[0125] The third screw shaft Xc1 has a rod shape with a circular cross section. A male thread is formed on the side surface of the third screw shaft Xc1. The male thread extends spirally in the front-to-rear direction. The third screw shaft Xc1 is located diagonally downward to the left of the third auxiliary shaft Xc2 and extends parallel to the third screw shaft Xc1. The third auxiliary shaft Xc2 is a D-cut shaft with a D-shaped cross section. The third screw shaft Xc1 rotates when driven by the third motor Mc1. The third auxiliary shaft Xc2 rotates when driven by the third auxiliary motor Mc2.

[0126] The pusher support portion 80C supports the pusher 5. The configuration of the pusher support portion 80C is common to the first grip support portion 80A shown in FIG. 15 and the second grip support portion 80B shown in FIG.

[0127] The pusher support portion 80C has a support base 83A, a second main gear 83B, and a second slave gear 83C. The support base 83A, the second main gear 83B, and the second slave gear 83C correspond to the support base 81A, the first main gear 81B, and the first slave gear 81C of the first grip support portion 80A shown in Fig. 15. A first through hole 831, a second through hole 832, and a third through hole 833 formed in the support base 83A correspond to the first through hole 811, the second through hole 812, and the third through hole 813 formed in the support base 81A shown in Fig. 15, respectively.

[0128] The third screw shaft Xc1 is inserted through the first through hole 831. The male thread of the third screw shaft Xc1 meshes with the female thread of the first through hole 831. The third auxiliary shaft Xc2 is inserted through the second through hole 832.

[0129] The second through-hole 832 and the gear through-hole 83H of the second main gear 83B are aligned in a straight line in the front-to-rear direction. The third auxiliary shaft Xc2 is inserted through the gear through-hole 83H. The second main gear 83B is movable in the front-to-rear direction relative to the third auxiliary shaft Xc2. The second main gear 83B rotates in response to the rotation of the third auxiliary shaft Xc2.

[0130] The second secondary gear 83C is provided at the rear end of the pusher 5. The pusher 5 extends forward from the second secondary gear 83C. The pusher 5 extends forward through the third through-hole 833. The second secondary gear 83C meshes with the second primary gear 83B. The second secondary gear 83C rotates in response to the rotation of the second primary gear 83B.

[0131] <Operation of Third Drive Mechanism 8C> The operation of the third drive mechanism 8C when moving the pusher 5 in the front-to-rear direction is the same as the operation of the first drive mechanism 8A shown in Fig. 15. The third drive mechanism 8C moves the pusher 5 in the front-to-rear direction in response to rotation of the third screw shaft Xc1 by driving of the third motor Mc1. The third drive mechanism 8C also rotates the pusher 5 in response to rotation of the third auxiliary shaft Xc2 by driving of the third auxiliary motor Mc2.

[0132] 14 , the positions of the first grip support portion 80A and the second grip support portion 80B are different from each other in the up-down direction and the left-right direction. Therefore, when the first grip support portion 80A and the second grip support portion 80B move in the front-rear direction, the first grip support portion 80A and the second grip support portion 80B do not come into contact with each other. Therefore, the first grip support portion 80A can move further forward than the second grip support portion 80B, and the second grip support portion 80B can move further forward than the first grip support portion 80A.

[0133] When viewed from the rear, the ligation grasping member 4A and the pusher 5 are arranged coaxially. The eighth axis C8 of the first rod 41, the ninth axis C9 of the second rod 42, and the tenth axis C10 of the pusher 5 are arranged on the same straight line. A portion of the first grip support portion 80A and the pusher support portion 80C overlap in directions (up-down and left-right directions) perpendicular to the front-to-rear direction. The pusher support portion 80C is arranged forward of the first grip support portion 80A. Movement of the first grip support portion 80A forward of the pusher support portion 80C is restricted by the rear surface of the pusher support portion 80C contacting the front surface of the first grip support portion 80A.

[0134] On the other hand, the positions of the second grip support portion 80B and the pusher support portion 80C are different from each other in the up-down and left-right directions. Therefore, when the second grip support portion 80B and the pusher support portion 80C move forward and backward, they do not come into contact with each other. Therefore, the second grip support portion 80B can move further forward than the pusher support portion 80C, and the pusher support portion 80C can move further forward than the second grip support portion 80B.

[0135] 29 , the robot R has a controller 96, a memory 97, a motor driver Fr, a plurality of robot motors MR, an encoder Zr, an input unit 98A, and an output unit 98B. The ligation device 1 has motor drivers Fa1, Fa2, Fb1, Fb2, Fc1, and Fc2, first motors Ma1 and Mb1, first auxiliary motors Ma2 and Mb2, third motor Mc1, third auxiliary motor Mc2, and encoders Za1, Za2, Zb1, Zb2, Zc1, and Zc2.

[0136] The controller 96 is a CPU (Central Processing Unit) and controls the ligation device 1 so that the ligation device 1 ligates the object S with the suture T. The controller 96 is electrically connected to the memory 97, the motor drivers Fr, Fa1, Fa2, Fb1, Fb2, Fc1, Fc2, the encoders Zr, Za1, Za2, Zb1, Zb2, Zc1, Zc2, the input unit 98A, and the output unit 98B.

[0137] The memory 97 includes volatile and nonvolatile storage devices, and stores a ligation program executed by the controller 96 and various setting information.

[0138] The motor driver Fr is electrically connected to the robot motor MR. The encoder Zr detects the rotation speed of the robot motor MR. The motor driver Fa1 is electrically connected to the first motor Ma1. The encoder Za1 detects the rotation speed of the first motor Ma1. The motor driver Fa2 is electrically connected to the first auxiliary motor Ma2. The encoder Za2 detects the rotation speed of the first auxiliary motor Ma2. The motor driver Fb1 is electrically connected to the second motor Mb1. The encoder Zb1 detects the rotation speed of the second motor Mb1. The motor driver Fb2 is electrically connected to the second auxiliary motor Mb2. The encoder Zb2 detects the rotation speed of the second auxiliary motor Mb2. The motor driver Fc1 is electrically connected to the third motor Mc1. The encoder Zc1 detects the rotation speed of the third motor Mc1. The motor driver Fc2 is electrically connected to the third auxiliary motor Mc2. The encoder Zc2 detects the rotation speed of the third auxiliary motor Mc2.

[0139] The motor driver Fr applies a DC voltage to the robot motor MR in response to a signal received from the controller 96, thereby driving the robot motor MR. The motor driver Fr also obtains the current value of the current flowing through the robot motor MR and the number of rotations of the robot motor MR detected by the encoder Zr, and sends these to the controller 96.

[0140] The motor driver Fa1 applies a DC voltage to the first motor Ma1 in response to a signal received from the controller 96, thereby driving the first motor Ma1. The motor driver Fa1 also obtains the current value of the current flowing through the first motor Ma1 and the rotation speed of the first motor Ma1 detected by the encoder Za1, and sends these to the controller 96. The motor driver Fa2 applies a DC voltage to the first auxiliary motor Ma2 in response to a signal received from the controller 96, thereby driving the first auxiliary motor Ma2. The motor driver Fa2 also obtains the current value of the current flowing through the first auxiliary motor Ma2 and the rotation speed of the first auxiliary motor Ma2 detected by the encoder Za2, and sends these to the controller 96.

[0141] The motor driver Fb1 applies a DC voltage to the second motor Mb1 in response to a signal received from the controller 96, thereby driving the second motor Mb1. The motor driver Fb1 also obtains the current value of the current flowing through the second motor Mb1 and the rotation speed of the second motor Mb1 detected by the encoder Zb1, and sends these to the controller 96. The motor driver Fb2 applies a DC voltage to the second auxiliary motor Mb2 in response to a signal received from the controller 96, thereby driving the second auxiliary motor Mb2. The motor driver Fb2 also obtains the current value of the current flowing through the second auxiliary motor Mb2 and the rotation speed of the second auxiliary motor Mb2 detected by the encoder Zb2, and sends these to the controller 96.

[0142] The motor driver Fc1 applies a DC voltage to the third motor Mc1 in response to a signal received from the controller 96, thereby driving the third motor Mc1. The motor driver Fc1 also obtains the current value of the current flowing through the third motor Mc1 and the rotation speed of the third motor Mc1 detected by the encoder Zc1, and sends these to the controller 96. The motor driver Fc2 applies a DC voltage to the third auxiliary motor Mc2 in response to a signal received from the controller 96, thereby driving the third auxiliary motor Mc2. The motor driver Fc2 also obtains the current value of the current flowing through the third auxiliary motor Mc2 and the rotation speed of the third auxiliary motor Mc2 detected by the encoder Zc2, and sends these to the controller 96.

[0143] The input unit 98A is a button, a touch panel, a keyboard, etc. for inputting various information to the robot R. The output unit 98B is a display for displaying various information.

[0144] <Ligation Process> The ligation process will be described in which the controller 96 of the robot R controls the ligation device 1 to ligate the object S to be ligated with the suture T. In the following description, the act of the controller 96 driving the motor by sending a signal to the driver will be referred to as "the controller 96 driving the motor." As shown in Figure 30, the ligation process is started with the ligation device 1 in an initial state (S11). The initial state is as follows:

[0145] As shown in FIG. 34 , the second jaw 3B is positioned in the proximal position. When the first ligation process is performed after replacing the cartridge 7, the tongue member 6 is positioned in the retracted position. The downstream end 60F of the tongue member 6 is positioned rearward of the 14th hole 7H of the cartridge 7 and in the 13th hole 31B in the jaw body 20A. At this time, the suture T is not held by the tongue member 6. On the other hand, when the second or subsequent ligation process is performed after replacing the cartridge 7, the tongue member 6 is positioned in the intermediate position. The intermediate position is the position of the tongue member 6 when the downstream end 60F is positioned in the 12th hole 31A of the second jaw 3B. At this time, the suture T is captured by the capturing portion 64 of the tongue member 6.

[0146] The ligating and grasping member 4A and the pusher 5 are disposed over the extension portion 21A and first branch portion 21B of the first hole 21, as well as the first circular portion 761, the recovery portion 71A, the second circular portion 762, and part of the region 780 of the cartridge 7 shown in FIG. 10 . The front ends of the ligating and grasping member 4A and the pusher 5 are located near the first jaw through-hole 33. The front end of the ligating and grasping member 4A protrudes slightly forward beyond the front end of the pusher 5. The ligating and grasping member 4A is in a released state. The repositioning grasping member 4B is disposed in the second branch portion 21C of the first hole 21. The repositioning grasping member 4B is in a fully grasping state.

[0147] The suture T unwound from the bobbin B passes through the twelfth hole 31A of the second jaw 3B, the first circular portion 761, the recovery portion 71A, and the second circular portion 762 of the cartridge 7, and the extension portion 21A and second branch portion 21C of the first hole 21. The tip of the suture T is gripped by the rearrangement gripping member 4B in the full gripping state. The first loop shaft 46 and the second loop shaft 56 of the loop forming portion 2B are positioned at the third rotation position. A first loop P1 is formed on the first loop shaft 46, and a second loop P2 is formed on the second loop shaft 56. The ligation gripping member 4A and the pusher 5 are inserted through the first loop P1 and the second loop P2. For ease of understanding, FIGS. 34 to 63 show the first loop P1 and the second loop P2 disengaged from the first loop shaft 46 and the second loop shaft 56.

[0148] The main body 2A of the ligation device 1 is positioned posterior to the body S to be ligated inside the body. The controller 96 drives the robot motor MR to operate the fourth operating wire to move the second jaw 3B from the close position to the distant position (S13). As shown in FIG. 35 , the second jaw 3B moves from the close position to the distant position (arrow Y11). In this state, the main body 2A moves forward toward the body S to be ligated. The body S to be ligated is positioned between the first jaw 3A and the second jaw 3B.

[0149] Next, the controller 96 drives the robot motor MR to operate the fourth operating wire to move the second jaw 3B from the distant position to the close position (S15). As shown in FIG. 36, the second jaw 3B moves from the distant position to the close position (arrow Y12). The object to be ligated S is sandwiched between the first jaw 3A and the second jaw 3B and positioned in the holding area Sp. The suture T is positioned below the object to be ligated S.

[0150] Next, the controller 96 drives the robot motor MR to operate the first operating wire in order to move the tongue member 6 to the protruding position in the first movement direction Y1 shown in FIGS. 27 and 28 (S17).

[0151] Here, when the first ligation process is performed after replacing the cartridge 7, the tongue member 6 moves from the retracted position to the protruding position. As the tongue member 6 moves, the first inclined portion 61 of the tongue member 6 shown in FIG. 27 comes into contact with a portion of the thread T that extends between the bobbin B and the object to be ligated S. As shown in FIG. 27 , the thread T is guided upstream in the first movement direction Y1 along the first inclined portion 61. The thread T leaves the first inclined portion 61 and then comes into contact with the second inclined portion 62. The thread T is guided upstream in the first movement direction Y1 along the first inclined portion 61. The thread T enters the slit 63 connected to the second inclined portion 62 and is clamped by the slit 63 from both the left and right sides.

[0152] On the other hand, when the second or subsequent ligation process is performed after replacing the cartridge 7, the tongue member 6 moves from the intermediate position to the protruding position. At this time, the suture T, which is captured by the capturing portion 64 of the tongue member 6, moves upstream in the first movement direction Y1 and enters the slit 63 as the tongue member 6 moves. The suture T is clamped on both the left and right sides by the slit 63.

[0153] The tongue member 6, with the suture T clamped therein, further moves in the first movement direction Y1 toward the protruding position. As shown in FIG. 37 , the downstream end 60F of the tongue member 6 is inserted through the first jaw through-hole 33 of the first jaw 3A and protrudes upward (arrow Y13). The downstream end 60F of the tongue member 6 faces forward relative to the ligation grasping member 4A. The tongue member 6 lifts the suture T clamped by the slit 63 upward. At this time, the portion of the suture T extending between the tongue member 6 and the ligation target body S enters the first notch 40 and the first partial notch 480 of the ligation grasping member 4A in the released state shown in FIG. 24 .

[0154] Next, the controller 96 drives the first auxiliary motor Ma2 to rotate the second rod 42 of the ligation grasping member 4A to change from the released state to the semi-gripped state (S19). As shown in Fig. 38, the second rod 42 of the ligation grasping member 4A rotates relative to the first rod 41 (arrow Y14), and the ligation grasping member 4A enters the semi-gripped state. The portion of the suture T extending between the tongue member 6 and the object to be ligated S is movably held by the first rod 41 and second rod 42 of the ligation grasping member 4A, which is now in the semi-gripped state.

[0155] Next, the controller 96 drives the robot motor MR to operate the first operating wire to move the tongue member 6 from the protruding position to the intermediate position (S21). As shown in FIG. 39 , the tongue member 6 moves in the second movement direction Y2 to the intermediate position (arrow Y15). At this time, the thread T comes off the slit 63. The thread T enters the catching portion 64, which is located upstream of the slit 63 in the second movement direction Y2, in other words, downstream of the first movement direction Y1, and is caught by the catching portion 64. Therefore, even if the thread T comes off the slit 63, it does not come off the tongue member 6.

[0156] Next, the controller 96 drives the first motor Ma1 and the third motor Mc1 to move the ligating and grasping member 4A and the pusher 5 rearward (S23). As shown in FIG. 39 , the ligating and grasping member 4A and the pusher 5 move rearward (arrow Y16). The front ends of the ligating and grasping member 4A and the pusher 5 are positioned rearward of the cartridge 7 and forward of the loop forming unit 2B. Note that the ligating and grasping member 4A is in a semi-gripped state, and the suture T is movable relative to the first rod 41 and the second rod 42. Therefore, as the ligating and grasping member 4A moves rearward, the suture T is unwound from the bobbin B. The suture T is wound around the object S to be ligated.

[0157] Next, the controller 96 drives the first auxiliary motor Ma2 to rotate the second rod 42 of the ligating grasping member 4A to change from the partial grasping state to the full grasping state (S25). As shown in Figure 40, the second rod 42 of the ligating grasping member 4A rotates relative to the first rod 41 (arrow Y17), and the ligating grasping member 4A enters the full grasping state. The portion of the suture T that has been unwound from the bobbin B is held immovably by the first rod 41 and second rod 42 of the ligating grasping member 4A, which is now in the full grasping state.

[0158] Next, the controller 96 drives the robot motor MR to operate the first operating wire in order to move the tongue member 6 from the intermediate position to the protruding position (S27). As the tongue member 6 moves, the portion of the suture T that extends between the bobbin B and the ligation grasping member 4A moves from the capturing portion 64 of the tongue member 6 toward the slit 63 and is clamped by the slit 63. The tongue member 6, with the suture T clamped therein, moves further toward the protruding position.

[0159] As shown in FIG. 41 , the downstream end 60F of the tongue member 6 is inserted through the first jaw through-hole 33 of the first jaw 3A and protrudes upward (arrow Y18). The suture T is clamped in the slit 63. The tongue member 6 lifts the suture T clamped in the slit 63 upward. At this time, the portion of the suture T extending between the tongue member 6 and the ligature gripping member 4A is pressed from below against the blade 79A of the gripping suture cutter 79 of the cartridge 7. Note that the ligature gripping member 4A is in a fully gripping state, and the suture T is immovable relative to the first rod 41 and the second rod 42. Furthermore, the suture T is clamped in the slit 63 of the tongue member 6, and the suture T is immovable relative to the tongue member 6. Therefore, the portion extending between the tongue member 6 and the ligature gripping member 4A is cut by the gripping suture cutter 79 (S27).

[0160] Of the thread T, the thread T1 that has been cut and separated from the bobbin B side is held by the rearrangement holding member 4B at a first end ta on one side. The thread T1 extends forward from the first end ta, wraps around the ligation target S, extends rearward, bends at the portion held by the ligation holding member 4A, extends forward, and reaches a second end tb on the other side. The thread T1 is wound around the ligation target S.

[0161] Next, the controller 96 drives the first auxiliary motor Ma2 to rotate the second rod 42 of the ligating grasping member 4A to change from the fully gripped state to the semi-gripped state (S29). As shown in Fig. 41, the second rod 42 of the ligating grasping member 4A rotates relative to the first rod 41 (arrow Y19), and the ligating grasping member 4A enters the semi-gripped state. The portion of the suture T1 extending between the second end tb cut in step S27 and the portion wound around the ligation target S is held by the first rod 41 and the second rod 42 of the ligating grasping member 4A, which is now in the semi-gripped state.

[0162] Next, the controller 96 drives the robot motor MR to operate the first operating wire to move the tongue member 6 from the protruding position to the intermediate position (S31). As shown in Figure 42, the tongue member 6 moves in the second movement direction Y2 to the intermediate position (arrow Y20). The thread T falls out of the slit 63 and is captured by the capture portion 64.

[0163] Next, the controller 96 drives the first motor Ma1 and the third motor Mc1 to move the ligature grasping member 4A and the pusher 5 rearward (S33). As shown in FIG. 42 , the ligature grasping member 4A and the pusher 5 move rearward (arrow Y21). The front ends of the ligature grasping member 4A and the pusher 5 move rearward behind the loop forming section 2B. Note that the ligature grasping member 4A is in a semi-gripped state, allowing the suture T1 to move relative to the first rod 41 and the second rod 42. Therefore, as the ligature grasping member 4A and the pusher 5 move rearward, the second end tb of the suture T1 passes rearward through the first loop P1 and the second loop P2 and moves to a position close to the first rod 41 and the second rod 42 of the ligature grasping member 4A.

[0164] Next, the controller 96 drives the first auxiliary motor Ma2 to rotate the second rod 42 of the ligating grasping member 4A to change from the partial grasping state to the full grasping state (S35). As shown in Figure 43, the second rod 42 of the ligating grasping member 4A rotates relative to the first rod 41 (arrow Y22), and the ligating grasping member 4A changes to the full grasping state. The vicinity of the second end tb of the suture T1 is held by the first rod 41 and the second rod 42 of the ligating grasping member 4A, which is now in the full grasping state.

[0165] Next, the controller 96 drives the first motor Ma1 and the third motor Mc1 to slightly move the ligation gripping member 4A and the pusher 5 forward (S37). As shown in FIG. 44, the ligation gripping member 4A and the pusher 5 move slightly forward (arrow Y23). The front ends of the ligation gripping member 4A and the pusher 5 approach the loop forming unit 2B from behind. This releases the tension between the portion of the suture T1 wound around the object S and the second end tb.

[0166] Next, the controller 96 drives the robot motor MR to operate the third operating wire in order to drive the loop forming unit 2B (S39). As shown in Figure 45, the first loop shaft 46 and the second loop shaft 56 rotate 360 ​​degrees in the first rotation direction R1 from the third rotation position. The first loop P1 disengages from the first loop shaft 46, and the second loop P2 disengages from the second loop shaft 56.

[0167] Next, as shown in Fig. 31, the controller 96 drives the first motor Ma1 and the third motor Mc1 to move the ligation grasping member 4A and the pusher 5 forward (S41). As shown in Fig. 46, the ligation grasping member 4A and the pusher 5 move forward (arrow Y24). The front ends of the ligation grasping member 4A and the pusher 5 move to the vicinity of the ligation target body S. At this time, the pusher 5 moves the first loop P1 and the second loop P2 to the vicinity of the ligation target body S. Fig. 47 shows the first loop P1 and the second loop P2 positioned near the ligation target body S.

[0168] The controller 96 also drives the second motor Mb1 to move the rearwardly repositioning and gripping member 4B (S43). As shown in FIG. 46, the rearwardly repositioning and gripping member 4B moves (arrow Y25). This suppresses slack in the yarn T1 due to the movement of the first loop P1 and the second loop P2. Next, the controller 96 executes a tightening step to tighten the first loop P1 and the second loop P2 (S45).

[0169] The tightening process will be described with reference to Figure 32. The controller 96 drives the second motor Mb1 to move the rearward gripping member 4B (S101). The controller 96 receives and acquires from the motor driver Fb1 the value of the current flowing through the second motor Mb1 in response to the driving of the second motor Mb1 by the motor driver Fb1 (S103).

[0170] The controller 96 determines whether the acquired current value is equal to or less than a predetermined threshold value Th0 (S105). If the current value flowing through the second motor Mb1 is greater than the predetermined threshold value Th0 (S105: YES), there is a high possibility that some abnormality has occurred in the ligation device 1. Therefore, if the controller 96 determines that the acquired current value is greater than the predetermined threshold value Th0 (S105: NO), it causes the output unit 98B to display a screen notifying the occurrence of an error (S107). The controller 96 then terminates the tightening process and the ligation process.

[0171] When the controller 96 determines that the acquired current value is equal to or less than the predetermined threshold value Th0 (S105: YES), the controller 96 drives the second motor Mb1 to continue moving the rearward of the rearrangement gripping member 4B (S109). Note that the vicinity of the second end tb of the suture T1 is held by the first rod 41 and the second rod 42 of the ligation gripping member 4A, which is in the full-holding state. The rearrangement gripping member 4B is also in the full-holding state, and the first end ta of the suture T1 is held by the first rod 43 and the second rod 44. Therefore, as the rearward movement of the rearrangement gripping member 4B pulls the suture T1, tightening the first loop P1 and the second loop P2.

[0172] The controller 96 selects a determination condition for whether or not to stop the rearward movement of the rearrangement gripping member 4B that started in S109 based on the setting information stored in the memory 97 (S111). The setting information is stored in the memory 97 by being input in advance by the user via the input unit 98A of the robot R. The selectable determination condition is any one of the following determination conditions G1 to G8. Details of the determination conditions G1 to G8 are as follows:

[0173] The first graph in Figure 33 shows the change over time in the value of the current flowing to the second motor Mb1 when the rearrangement gripping member 4B moves rearward. As such, the current value increases as the time passes while the rearrangement gripping member 4B moves. The current value flowing to the second motor Mb1 correlates with the magnitude of the force with which the rearrangement gripping member 4B moves rearward and pulls the thread T1. In other words, as the movement of the rearrangement gripping member 4B gradually tightens the first loop P1 and the second loop P2, the force with which the rearrangement gripping member 4B pulls the thread T1 also gradually increases. Therefore, the vertical axis of the first graph can be replaced with the force with which the rearrangement gripping member 4B pulls the thread T1. In the following explanation, the vertical axis of the first graph will be replaced with force.

[0174] The force change trend includes an initial state H1, an intermediate state H2, and a final state H3. In the initial state H1, the force changes at a constant rate of increase. In the intermediate state H2, the rate of increase of the force increases. In the final state H3, the force changes at a constant rate of increase. Note that the rate of increase of the force in the final state H3 is greater than the rate of increase of the force in the initial state H1.

[0175] The second graph in Figure 33 shows the change over time in the first derivative, which is the value obtained by first differentiating the time change of the force in the first graph. The first state H11, second state H12, and third state H13 in the second graph correspond to the initial state H1, intermediate state H2, and final state H3 in the first graph, respectively. The third graph in Figure 33 shows the change over time in the second derivative, which is the value obtained by second-differentiating the time change of the force in the first graph. The fourth state H21, fifth state H22, and sixth state H23 in the third graph correspond to the initial state H1, intermediate state H2, and final state H3 in the first graph, respectively.

[0176] In the determination conditions G1 to G3, the determination is made based on a first derivative value obtained by differentiating the time change of the force once, while in the determination conditions G4 to G8, the determination is made based on a second derivative value obtained by differentiating the time change of the force twice.

[0177] In the judgment condition G1, when the state changes from the first state H11 to the second state H12, it is judged that the rearward movement of the rearward gripping member 4B is to be stopped. More specifically, when the state changes from a state in which the first derivative value fluctuates within a range within a predetermined first percentage W1 (%) of the moving average value of the first derivative value to a state in which the first derivative value fluctuates within a range greater than the first percentage W1 (%), the controller 96 judges that the state has changed from the first state H11 to the second state H12. When the controller 96 determines that the state has changed from the first state H11 to the second state H12, it determines that the rearward movement of the rearward gripping member 4B is to be stopped.

[0178] In the judgment condition G2, if, after a change from the first state H11 to the second state H12, the first differential value becomes larger than a predetermined first threshold value Th1 with respect to a value statistically derived from the first differential value in the first state H11, the controller 96 judges that the rearward movement of the rearward gripping member 4B should be stopped. More specifically, if, after a change to the second state H12, the first differential value becomes larger than the first threshold value Th1 with respect to the moving average value of the first differential value in the first state H11, the controller 96 judges that the rearward movement of the rearward gripping member 4B should be stopped.

[0179] In the judgment condition G3, when the state changes from the second state H12 to the third state H13, it is judged that the rearward movement of the rearward gripping member 4B is to be stopped. More specifically, when, after the state changes to the second state H12, the state changes to one in which the first differential value fluctuates within a range of a first ratio W1 (%) with respect to the moving average value of the first differential value, the controller 96 judges that the state has changed from the second state H12 to the third state H13. When it is determined that the state has changed from the second state H12 to the third state H13, the controller 96 judges that the rearward movement of the rearward gripping member 4B is to be stopped.

[0180] In the judgment condition G4, when the state changes from the fourth state H21 to the fifth state H22, it is judged that the rearward movement of the rearward gripping member 4B is to be stopped. More specifically, when the state changes from a state in which the second derivative value fluctuates within a range within a predetermined second percentage W2 (%) of the moving average value of the second derivative value to a state in which the second derivative value fluctuates within a range greater than the second percentage W2 (%), the controller 96 judges that the state has changed from the fourth state H21 to the fifth state H22. When the controller 96 determines that the state has changed from the fourth state H21 to the fifth state H22, it determines that the rearward movement of the rearward gripping member 4B is to be stopped.

[0181] In the judgment condition G5, if, after a change from the fourth state H21 to the fifth state H22, the second differential value becomes larger than a value statistically derived from the second differential value in the fourth state H21 by a predetermined second threshold value Th2 or more, it is judged that the rearward movement of the rearward gripping member 4B is to be stopped. More specifically, if, after a change to the fifth state H22, the second differential value becomes larger than the moving average value of the second differential value in the fourth state H21 by the second threshold value Th2 or more, the controller 96 judges that the rearward movement of the rearward gripping member 4B is to be stopped.

[0182] In the judgment condition G6, if the second differential value becomes a maximum after the state changes from the fourth state H21 to the fifth state H22, it is judged that the rearward movement of the rearward gripping member 4B should be stopped. More specifically, the controller 96 detects, as a maximum point, a point at which the value obtained by differentiating the second differential value becomes 0 after the state changes to the fifth state H22. When the controller 96 detects a maximum point, it judges that the rearward movement of the rearward gripping member 4B should be stopped.

[0183] In the judgment condition G7, if the second differential value becomes smaller than the maximum value of the maximum point by a predetermined third threshold value Th3 or more after the state changes from the fourth state H21 to the fifth state H22, it is judged that the rearward movement of the rearrangement gripping member 4B should be stopped. More specifically, if the controller 96 detects a maximum point after the state changes to the fifth state H22, it identifies the maximum value of the maximum point. If the second differential value becomes smaller than the identified maximum value by the third threshold value Th3 or more, the controller 96 judges that the rearward movement of the rearrangement gripping member 4B should be stopped.

[0184] In the judgment condition G8, if the state changes from the fifth state H22 to the sixth state H23, it is judged that the rearward movement of the rearward gripping member 4B is to be stopped. More specifically, if, after the state changes to the fifth state H22, the state changes to one in which the second differential value fluctuates within a range of a second ratio W2 (%) with respect to the moving average value of the second differential value, the controller 96 judges that the state has changed from the fifth state H22 to the sixth state H23. If the controller 96 determines that the state has changed from the fifth state H22 to the sixth state H23, it determines that the rearward movement of the rearward gripping member 4B is to be stopped.

[0185] As shown in FIG. 32 , after selecting one of the judgment conditions G1 to G9 in S111, the controller 96 receives and acquires from the motor driver Fb1 the current value flowing through the second motor Mb1 in response to the drive of the second motor Mb1 by the motor driver Fb1 (S113). Based on the acquired current value, the controller 96 determines whether or not to stop the rearward movement of the rearrangement gripping member 4B in accordance with one of the judgment conditions G1 to G9 selected in S111 (S115). If the controller 96 determines not to stop the rearward movement of the rearrangement gripping member 4B (S115: NO), the process returns to S113 and repeats. In this case, as shown in FIG. 46 , the rearrangement gripping member 4B moves rearward (arrow Y25). This tightens the first loop P1 and the second loop P2.

[0186] If the controller 96 determines that the rearward movement of the rearrangement gripping member 4B should be stopped (S115: YES), it stops driving the second motor Mb1 in order to stop the movement of the rearrangement gripping member 4B (S117).

[0187] As shown in Fig. 31, the controller 96 then drives the first motor Ma1 to move the ligation grasping member 4A backward (S47). As shown in Fig. 48, the ligation grasping member 4A moves backward (arrow Y26). The controller 96 also drives the second motor Mb1 to move the rearrangement grasping member 4B forward (S47). As shown in Fig. 48, the rearrangement grasping member 4B moves forward (arrow Y27).

[0188] The movement of the ligation gripping member 4A and the rearrangement gripping member 4B extends the first loop P1 shown in Fig. 47. As shown in Fig. 49, a new first loop P11 is formed in the portion of the thread T1 between the second loop P2 and the first end ta. As a result, a man's knot K is formed, and the body S is ligated with the thread T1.

[0189] Next, the controller 96 drives the first auxiliary motor Ma2 to rotate the second rod 42 of the ligating grasp member 4A to change from the fully gripped state to the released state (S49). As shown in Figure 50, the second rod 42 of the ligating grasp member 4A rotates relative to the first rod 41 (arrow Y28), and the ligating grasp member 4A enters the released state. The vicinity of the second end tb of the suture T1 is released from the first rod 41 and the second rod 42 of the ligating grasp member 4A.

[0190] Next, the controller 96 drives the first motor Ma1 and the third motor Mc1 to move the ligature grasping member 4A and the pusher 5 rearward (S51). As shown in Figure 51, the ligature grasping member 4A and the pusher 5 move rearward (arrow Y29). The ligature grasping member 4A and the pusher 5 are disposed in the first branch portion 21B of the first hole 21.

[0191] Next, the controller 96 drives the robot motor MR to rotate the rotary belt 230 in order to cut the portion of the suture T1 from the portion wound around the ligation target object S to the first end ta and store the portion in the first storage portion 71B of the cartridge 7 (S53). The pulley 27 of the transmission mechanism 29 provided in the first portion mounting portion 28A of the jaw body 20A rotates in response to the rotation of the rotary belt 230. Accordingly, as shown in FIG. 52 , the rotating body 72 of the cartridge 7 mounted in the mounting hole 27A of the pulley 27 also rotates, and the reel member 73 connected to the rotating body 72 rotates (arrow Y30).

[0192] 53 , the thread T1 in contact with the reel member 73 is guided along the wires 730 of the first coil spring 73A and the second coil spring 73B. As a result, the thread T1 moves from the collection section 71A toward the first storage section 71B in the storage recess 71 of the cartridge 7. The thread T1 moves downward away from the movement trajectory U of the rearrangement gripping member 4B. More specifically, as the reel member 73 rotates, the thread T1 moves downward toward the connection points between the first coil spring 73A and the second coil spring 73B and the support plate 72A.

[0193] The first end ta of the yarn T1 is pulled forward as the yarn T1 moves from the collection section 71A toward the first storage section 71B in the storage recess 71. In response to this, the controller 96 drives the second motor Mb1 to move the rearrangement gripping member 4B forward (S55). As shown in Figure 52, the rearrangement gripping member 4B holding the first end ta of the yarn T1 moves forward (arrow Y31).

[0194] The reel member 73 continues to rotate even after the thread T1 has moved to the bottom end of the reel member 73. In this case, as shown in FIG. 54 , the thread T1 is wound onto the bottom end of the reel member 73. When the winding of the thread T1 onto the reel member 73 begins, the portion of the thread T1 that extends from the portion wound around the ligation target S toward the reel member 73 moves leftward from the center in the left-right direction of the cartridge 7. The thread T1 comes into contact with the winding thread cutter 77 of the cartridge 7 and is cut by the blade 77A (S57). The winding thread cutter 77 cuts off the portion of the thread T1 that extends from the knot K toward the first end ta from the knot K. Hereinafter, the portion of the thread T1 that has been cut off from the knot K will be referred to as thread T11.

[0195] After the yarn T1 is cut by the winding yarn cutter 77 of the cartridge 7, the controller 96 drives the second auxiliary motor Mb2 to rotate the second rod 44 of the rearrangement gripping member 4B to change from the fully gripped state to the released state (S59). As shown in Figure 55, the second rod 44 of the rearrangement gripping member 4B rotates relative to the first rod 43 (arrow Y32), and the rearrangement gripping member 4B enters the released state. The vicinity of the first end ta of the yarn T11 is released from the first rod 43 and the second rod 44 of the rearrangement gripping member 4B.

[0196] The controller 96 continues to rotate the pulley 27 of the jaw body 20A, and continues to rotate the reel member 73 of the cartridge 7 (arrow Y33). As a result, the yarn T11 is completely wound onto the reel member 73 (S61). The wound yarn T11 is stored in the first storage section 71B of the storage recess 71. The volume of the first storage section 71B is adjusted to be at least twice the total volume of the yarn T11 wound onto the reel member 73 through the above process, but not greater than the total volume of the yarn T wound around the bobbin B in an uncompressed state.

[0197] Next, the controller 96 drives the robot motor MR to operate the third operating wire (S63) in order to rotate the first loop shaft 46 and the second loop shaft 56. As shown in Fig. 56, the first loop shaft 46 and the second loop shaft 56 rotate 180 degrees in the second rotation direction R2 from the third rotation position toward the first rotation position.

[0198] Next, the controller 96 drives the robot motor MR to operate the fourth operating wire to move the second jaw 3B from the close position to the distant position (S65). As shown in Figure 56, the second jaw 3B moves from the close position to the distant position (arrow Y34). The ligated body S, which has been ligated with the thread T1, is removed from the jaw members 3.

[0199] Next, the controller 96 drives the robot motor MR to operate the fourth operating wire in order to move the second jaw 3B from the distant position to the close position (S67). As shown in Fig. 56, the second jaw 3B moves from the distant position to the close position (arrow Y35).

[0200] <Repositioning Step> After the ligation step in which the object S to be ligated is ligated with the suture T, the repositioning step in which the ligation device 1 is returned to its initial state will be described.

[0201] As shown in Fig. 57, the controller 96 drives the second motor Mb1 to move the rearrangement gripping member 4B forward (S71). As shown in Fig. 58, the rearrangement gripping member 4B moves forward (arrow Y51). The rearrangement gripping member 4B is disposed over the extension portion 21A and second branch portion 21C of the first hole 21, as well as the first circular portion 761, the collection portion 71A, the second circular portion 762, and part of the region 780 of the cartridge 7 shown in Fig. 10. The front end of the rearrangement gripping member 4B reaches the vicinity of the first jaw through-hole 33 of the first jaw 3A.

[0202] Next, the controller 96 drives the robot motor MR to operate the first operating wire in order to move the tongue member 6 from the intermediate position to the protruding position (S73). During the process of the tongue member 6 moving in the first movement direction Y1, the thread T captured by the capturing portion 64 enters the slit 63 and is clamped by the slit 63.

[0203] The tongue member 6, while holding the thread T, further moves in the first movement direction Y1 toward the protruding position. As shown in Figure 59, the downstream end 60F of the tongue member 6 is inserted into the first jaw through-hole 33 of the first jaw 3A and protrudes upward (arrow Y53). The tongue member 6 lifts the thread T held by the slit 63 upward. At this time, the tip of the thread T enters the first notch 40 and the first partial notch 480 of the released repositioning gripping member 4B. The downstream end 60F of the tongue member 6 faces forward relative to the repositioning gripping member 4B.

[0204] Next, the controller 96 drives the second auxiliary motor Mb2 to rotate the second rod 44 of the rearrangement gripping member 4B to change from the released state to the fully gripped state (S75). As shown in Figure 59, the second rod 44 of the rearrangement gripping member 4B rotates relative to the first rod 43 (arrow Y54), and the rearrangement gripping member 4B enters the fully gripped state. The tip of the yarn T is held immovably by the first rod 43 and the second rod 44 of the rearrangement gripping member 4B, which is now in the fully gripped state.

[0205] Next, the controller 96 drives the robot motor MR to operate the first operating wire to move the tongue member 6 from the protruding position to the intermediate position (S77). As shown in Figure 60, the tongue member 6 moves in the second movement direction Y2 to the intermediate position (arrow Y55). The thread T leaves the slit 63 and is captured by the capturing portion 64.

[0206] Next, the controller 96 drives the second motor Mb1 to move the rearwardly relocating and gripping member 4B (S79). As shown in FIG. 61 , the rearwardly relocating and gripping member 4B moves (arrow Y56). The front end of the rearwardly relocating and gripping member 4B is positioned rearwardly of the loop forming unit 2B. Note that the rearwardly relocating and gripping member 4B is in a fully gripping state, and the yarn T cannot move relative to the first rod 43 and the second rod 44. Therefore, as the rearwardly relocating and gripping member 4B moves, the yarn T is unwound from the bobbin B.

[0207] Next, the controller 96 drives the robot motor MR to drive the loop former 2B and operate the third operating wire (S81). As shown in Fig. 62, the first loop shaft 46 and the second loop shaft 56 rotate 90 degrees in the first rotation direction R1 from the first rotation position to the second rotation position. As a result, the yarn T arranged along the second groove 460A moves to the fourth groove 460B and the fifth groove 460C, and the yarn T arranged along the third groove 560A moves to the sixth groove 560B and the seventh groove 560C.

[0208] Next, the controller 96 drives the second motor Mb1 to move the rearwardly repositioning and gripping member 4B (S83). As shown in Figure 63, the rearwardly repositioning and gripping member 4B moves (arrow Y57). The front end of the rearwardly repositioning and gripping member 4B reaches the second branch portion 21C of the first hole 21.

[0209] Next, the controller 96 drives the second motor Mb1 to move the rearrangement gripping member 4B forward (S85). The rearrangement gripping member 4B moves slightly forward (arrow Y58). The controller 96 also drives the robot motor MR to drive the loop forming unit 2B and manipulates the third operating wire (S87). As shown in FIG. 63 , the first loop shaft 46 and the second loop shaft 56 rotate 270 degrees in the second rotation direction R2 from the second rotation position toward the third rotation position. As a result, as shown in FIG. 64 , a first loop P1 is formed on the first loop shaft 46, and a second loop P2 is formed on the second loop shaft 56.

[0210] Next, the controller 96 drives the third motor Mc1 to move the pusher 5 forward (S89). The front end of the pusher 5 protrudes forward beyond the ligation grasping member 4A. Next, the controller 96 drives the first motor Ma1 and the third motor Mc1 to move the ligation grasping member 4A and the pusher 5 forward (S91). As shown in FIG. 64 , the ligation grasping member 4A and the pusher 5 pass through the first loop P1 formed on the first loop shaft 46 of the loop forming unit 2B and the second loop P2 formed on the second loop shaft 56.

[0211] The controller 96 also drives the third auxiliary motor Mc2 to alternately rotate the pusher 5 each time the front end of the pusher 5 passes the suture T forming the first loop P1 and the second loop P2 (S93). As shown in FIG. 64, the pusher 5 alternately rotates 180 degrees to one side and the other side about the tenth axis C10 (arrow Y60). This allows the pusher 5 to move forward without getting caught on the first loop P1 and the second loop P2. After passing through the first loop P1 and the second loop P2, the front ends of the ligation gripping member 4A and the pusher 5 reach the vicinity of the front end of the main body 2A. This returns the ligation device 1 to its initial state.

[0212] <Actions and Effects of the Present Embodiment> The ligation device 1 forms a knot K in the suture T and ligates the ligation target object S by moving the relocation holding member 4B holding the suture T backward. Here, the drive conditions of the relocation holding member 4B for properly ligating the ligation target object S with the suture T are related to the time rate of change of force when pulling the suture T. Therefore, the ligation device 1 determines the timing to stop the movement of the relocation holding member 4B based on the time rate of change of force when pulling the suture T by the relocation holding member 4B (S115). This allows the ligation device 1 to pull the suture T with the relocation holding member 4B with an appropriate amount of force, thereby enabling the ligation target object S to be properly ligated with the suture T.

[0213] In the determination conditions G1 to G3, the timing to stop the movement of the rearrangement grasping member 4B is determined based on a first differential value obtained by differentiating the change in force with time once. In this case, the ligation device 1 can appropriately determine the drive condition of the rearrangement grasping member 4B required to pull the suture T with an appropriate force based on the first differential value.

[0214] In the determination conditions G4 to G8, the timing to stop the movement of the rearrangement grasping member 4B is determined based on the second differential value obtained by differentiating the change in force over time twice. In this case, the ligation device 1 can appropriately determine the drive conditions of the rearrangement grasping member 4B required to pull the suture T with an appropriate force based on the second differential value.

[0215] The applicant measured the force used by several doctors when they actually pulled the suture T to ligate the ligation target body S with the suture T. The results revealed that several doctors tended to pull the suture T with a force corresponding to the intermediate state H2 in the first graph shown in FIG. 33 . In other words, it is presumed that the optimal force when pulling the suture T to ligate the ligation target body S with the suture T is the force corresponding to the intermediate state H2 in the first graph shown in FIG. 33 . In response to this, the controller 96 determines whether or not to stop the rearward movement of the repositioning gripping member 4B based on the determination conditions G1 to G8, thereby enabling the suture T to be pulled with a force corresponding to the intermediate state H2 in the first graph. Therefore, the controller 96 can perform ligation of the ligation target body S using the ligation device 1 under appropriate conditions.

[0216] The ligation device 1 moves the first loop P1 and the second loop P2 formed by the loop forming unit 2B toward the ligation target body S using the pusher 5 (S41). Next, after the first loop P1 and the second loop P2 have moved toward the ligation target body S, the ligation device 1 moves the rearwardly the rearrangement gripping member 4B gripping the first end ta of the suture T to tighten the first loop P1 and the second loop P2 (S45). Next, the ligation device 1 moves the ligation gripping member 4A rearwardly to form a knot K from the first loop P1 and the second loop P2 (S47). Next, the ligation device 1 cuts the suture T using the wound suture cutter 77 of the cartridge 7 (S57). The controller 96 can appropriately control the movement conditions of the rearrangement gripping member 4B when the ligation device 1 tightens the first loop P1 and the second loop P2 during a series of operations to ligate the ligation target object S with the thread T.

[0217] <Modifications> The present invention is not limited to the above-described embodiment, and various modifications are possible. A controller may be built into the ligation device 1. The ligation device 1 may execute the ligation step by having its built-in controller execute the processes shown in Figures 30 to 32. Furthermore, the ligation device 1 may execute the rearrangement step by having its built-in controller execute the process shown in Figure 57.

[0218] Separate controllers may be provided for the ligation process and the rearrangement process. Furthermore, the ligation process may be performed by multiple controllers, and the rearrangement process may be performed by multiple controllers. The controller is not limited to a CPU, but may also be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system on chip (SoC), or the like.

[0219] The controller 96 may acquire a parameter other than the current value flowing through the second motor Mb1 as a parameter correlated with the magnitude of the force exerted when the rearrangement gripping member 4B moves rearward to pull the suture T1. For example, the controller 96 may acquire the number of rotations of the second motor Mb1 detected by the encoder Zb1 instead of the current value. The controller 96 may determine the magnitude of the force exerted when the rearrangement gripping member 4B moves rearward to pull the suture T1 based on the acquired number of rotations. The controller 96 may determine whether or not to stop the rearward movement of the rearrangement gripping member 4B during ligation based on the determined magnitude of the force. Furthermore, for example, the ligation device 1 may include a sensor that directly measures the magnitude of the force exerted when the rearrangement gripping member 4B moves rearward to pull the suture T1. The controller 96 may determine whether or not to stop the rearward movement of the rearrangement gripping member 4B during ligation based on the magnitude of the force measured by the sensor.

[0220] The controller 96 selected one of the determination conditions G1 to G8 for determining whether or not to stop the rearward movement of the rearrangement gripping member 4B based on the setting information stored in the memory 97. Alternatively, the controller 96 may determine an appropriate determination condition from among the determination conditions G1 to G8 based on the patient's age, sex, the part of the body where the blood vessel is located, the hardness of the blood vessel, the diameter of the blood vessel, the thickness of the blood vessel, the flow pressure of the blood flowing through the blood vessel, the state of arteriosclerosis, the state of vascular stenosis, the state of thrombus formation, etc.

[0221] The determination based on the first derivative value obtained by differentiating the time change of the force once may be made based on a condition other than the determination conditions G1 to G3. The determination based on the second derivative value obtained by differentiating the time change of the force twice may be made based on a condition other than the determination conditions G4 to G8. The controller 96 may make the determination based on the nth derivative value obtained by differentiating the time change of the force n times (n is an integer equal to or greater than 3).

[0222] The ligation device 1 may be a device that only performs the action of pulling and tightening the suture T wound around the ligation target S. In this case, at least one of the formation of the first loop P1 and the second loop P2 by the loop forming unit 2B, the movement of the first loop P1 and the second loop P2 by the pusher 5, and the cutting of the suture T by the wound suture cutter 77 may be achieved by a separate device.

[0223] <Others> The rearrangement gripping member 4B is an example of a "first gripping member" in the present invention. Rear is an example of a "first direction" in the present invention. The ligation gripping member 4A is an example of a "second gripping member" in the present invention. The winding suture cutter 77 is an example of a "cutter" in the present invention.

[0224] 1: Ligating device 2B: Loop forming section 4B: Rearrangement gripping member 5: Pusher 77: Winding thread cutter 96: Controller 97: Memory H11: First state H12: Second state H13: Third state H21: Fourth state H22: Fifth state H23: Sixth state Zb1: Encoder

Claims

1. A ligation device comprising: a first gripping member that grips a portion of the thread wound around an object to be ligated and moves in a first direction away from the object to be ligated; a first motor that drives the first gripping member; and at least one controller that is electrically connected to the first motor and controls the driving of the first motor, wherein the controller: drives the first motor so that the first gripping member moves in the first direction while the first gripping member is gripping the thread, a portion of which is hooked on the object to be ligated; acquires a parameter that is correlated with the force when the first gripping member is moved in the first direction and the thread is pulled; determines whether or not to stop the movement of the first gripping member based on the time rate of change of the force identified based on the acquired parameter; and stops the driving of the first motor when it is determined that the first gripping member should be stopped.

2. The ligation device according to claim 1, characterized in that the controller, in making the judgment, determines whether or not to stop the movement of the first gripping member based on a first differential value obtained by differentiating the change in the force with respect to time once.

3. The ligation device according to claim 2, characterized in that the controller determines to stop the movement of the first gripping member when, in the determination, the state changes from a first state in which the first differential value changes within a range within a predetermined first ratio to a second state in which the first differential value changes within a range greater than the first ratio.

4. The ligation device according to claim 2, characterized in that, in the determination, the controller determines to stop movement of the first gripping member when the state changes from a first state in which the first derivative value changes within a range within a predetermined first ratio to a second state in which the first derivative value changes within a range greater than the first ratio, and further, after the change to the second state, the first derivative value becomes greater than a value statistically derived from the first derivative value in the first state by a predetermined first threshold value or more.

5. The ligation device according to claim 2, characterized in that, in the determination, the controller determines to stop the movement of the first gripping member when the state changes from a first state in which the first differential value changes within a range within a predetermined first ratio to a second state in which the first differential value changes within a range greater than the first ratio, and further, after changing to the second state, changes to a third state in which the first differential value changes within a range within the first ratio.

6. The ligation device according to claim 1, characterized in that the controller, in making the judgment, determines whether or not to stop the movement of the first gripping member based on a second differential value obtained by twice differentiating the change in the force over time.

7. The ligation device according to claim 6, characterized in that the controller determines to stop the movement of the first gripping member when the state changes from a fourth state in which the second differential value changes within a range within a predetermined second ratio to a fifth state in which the second differential value changes within a range greater than the second ratio.

8. The ligation device according to claim 6, characterized in that the controller, in making the determination, determines to stop the movement of the first gripping member when the state changes from a fourth state in which the second derivative value changes within a range smaller than a predetermined second ratio to a fifth state in which the second derivative value changes within a range larger than the second ratio, and further when, after the change to the fifth state, the second derivative value becomes larger than a value statistically derived from the second derivative value in the fourth state by a predetermined second threshold value or more.

9. The ligation device according to claim 6, characterized in that the controller, in making the judgment, judges to stop the movement of the first gripping member when the state changes from a fourth state in which the second differential value changes within a range within a predetermined second ratio to a fifth state in which the second differential value changes within a range greater than the second ratio, and when the second differential value becomes maximum after changing to the fifth state.

10. The ligation device according to claim 6, characterized in that the controller, in making the judgment, judges to stop the movement of the first gripping member when the state changes from a fourth state in which the second differential value changes within a range within a predetermined second ratio to a fifth state in which the second differential value changes within a range greater than the second ratio, the second differential value reaches a maximum after the change to the fifth state, and further, after the second differential value reaches a maximum, the second differential value becomes smaller than the maximum by a predetermined third threshold value or more.

11. The ligation device according to claim 6, characterized in that the controller determines to stop the movement of the first gripping member when, in the determination, the state changes from a fourth state in which the second differential value changes within a range within a predetermined second ratio to a fifth state in which the second differential value changes within a range greater than the second ratio, and further, after changing to the fifth state, the state changes to a sixth state in which the second differential value changes within a range within the second ratio.

12. A device further comprising: a loop forming unit that forms a loop in the thread; a pusher that moves the loop formed by the loop forming unit toward the body to be ligated; a second gripping member that grips a portion of the thread and moves in the first direction; a second motor that drives the second gripping member; and a cutter that cuts the thread, wherein the controller causes the loop forming unit to form the loop by wrapping a portion of the thread extending toward one end, the portion of the thread having a part hooked on the body to be ligated, the portion extending toward the other end of the thread, around the portion of the thread extending toward the other end; causes the pusher to move the loop formed by the loop forming unit toward the body to be ligated; and after the pusher has moved the loop toward the body to be ligated, drives the first motor so that the first gripping member gripping the portion of the thread extending toward the other end moves in the first direction to tighten the loop; 2. The ligation device according to claim 1, wherein, after the first gripping member moves in the first direction, the second motor is driven so that the second gripping member gripping the portion of the suture extending toward the one end moves in the first direction, thereby forming a knot from the loop; and after the knot is formed, the cutter cuts the portion of the suture between the portion gripped by the first gripping member and the knot.

13. A ligation system comprising: a ligation device including a first gripping member that grips a portion of the thread wound around the object to be ligated and moves in a first direction away from the object to be ligated, and a first motor that drives the first gripping member; and at least one controller that controls the driving of the first motor, wherein the controller: drives the first motor so that the first gripping member moves in the first direction while the first gripping member is gripping the thread, a portion of which is hooked on the object to be ligated; acquires a parameter that is correlated with the force when the first gripping member is moved in the first direction and the thread is pulled; determines whether or not to stop the movement of the first gripping member based on the time rate of change of the force identified based on the acquired parameter; and stops the driving of the first motor when it is determined that the first gripping member should be stopped.

14. A storage medium storing a program executable by at least one controller, wherein the program causes the controller to: drive a first motor so that a first gripping member gripping a portion of the thread wound around the object to move in a first direction away from the object to be ligated; acquire a parameter correlated with the force when the first gripping member is moved in the first direction to pull the thread; determine whether or not to stop the movement of the first gripping member based on the time rate of change of the force identified based on the acquired parameter; and stop driving the first motor when it is determined that the first gripping member should be stopped.

Images