Medical device

Abstract

A medical device (10) suppresses the movement of a surface of the heart (300) of a living person (P) by being brought into contact with the heart (300). The medical device (10) comprises a pair of attachment parts (58) which are attached to the heart (300) by suction, and also comprises first and second arm parts (141, 142) which are supported by a shaft (12) and which can be opened and closed. The first and second arm parts (141, 142) constitute a distal end part of the medical device (10).

Description

Medical Devices

[0001] The present invention relates to medical devices.

[0002] Japanese Patent Application Laid-Open Publication No. 2023-73318 discloses a medical device for controlling the beating of the human heart. The medical device includes a pair of arms attached to the rails of a sternal retractor and a pair of contact portions provided at the tips of the arms. During thoracotomy, the pair of contact portions are inserted into the living body through an opening, and the ends of the pair of contact portions are brought into contact with the surface of the heart to control the movement of the surface due to the beating of the heart.

[0003] Japanese Patent Application Laid-Open No. 2023-73318

[0004] In thoracotomy, a small opening is made near the incision to reduce the burden on the living body, a shaft is inserted into the living body through the opening, and a medical device is attached to the tip of the shaft. In this case, after the shaft is inserted into the living body through the opening with a cap attached to the tip, it is necessary to remove the cap inside the living body and attach a medical device (stabilizer) to the tip of the shaft.

[0005] However, the process of removing the cap inside the body and attaching the medical device to the tip of the shaft is cumbersome, and there is also the risk of accidentally dropping the cap inside the body (surgical field) after removing it inside the body, which necessitates the additional task of retrieving the dropped cap from the body (surgical field), which would not normally be required.

[0006] The present invention aims to solve the above-mentioned problems.

[0007] (1) An aspect of the present invention is a medical device that suppresses movement of the surface of an organ of a living body by contacting the organ, the medical device comprising: a shaft that is inserted into the living body; and a pair of openable and closable arm portions supported by the shaft, which constitute the tip of the medical device and have a pair of suction portions that suction the organ.

[0008] According to this medical device, the pair of arms can be opened and closed, and thus can be inserted into the living body through an opening in the living body when the pair of arms is closed. Therefore, unlike a structure in which a cap is removed from the tip of the shaft inside the living body and a medical device (stabilizer) is attached to the tip of the shaft, it is possible to prevent the cap from falling into the surgical field.

[0009] (2) In the medical device described in (1) above, the shaft may have a cylindrical outer rod, an inner rod inserted into the inner cavity of the outer rod, and a support structure provided at the tip of the inner rod and supporting the pair of arm portions so that they can be opened and closed, the outer rod and the inner rod may be relatively movable in the axial direction of the outer rod, and the outer rod may have an arm accommodating space that can accommodate at least the base ends of the pair of arm portions when the pair of arm portions are closed.

[0010] With this configuration, the pair of arm portions are accommodated in the arm accommodating space of the outer rod in a closed state, so that when the pair of arm portions are inserted into the living body, the insertion resistance of the pair of arm portions is effectively suppressed.

[0011] (3) In the medical device described in (2) above, at a first position where the outer rod has moved distally relative to the inner rod, the pair of arm sections may be in a closed state, with the tips of the arm sections rotated in a direction approaching each other, with the support portion of the support structure as a fulcrum, and at a second position where the outer rod has moved proximally relative to the inner rod, the pair of arm sections may be in an open state, with the tips of the pair of arm sections rotated away from each other, with the support portion of the support structure as a fulcrum.

[0012] With this configuration, the arm portion is inserted into the living body in a first position where the arm portion is closed, and then rotated inside the living body to a second position where the arm portion is open, thereby enabling the arm portion to be easily inserted into the living body while also being able to maintain the surface of the organ.

[0013] (4) The medical device described in (3) above may further include an operating portion provided at the base end of the outer rod for opening and closing the pair of arms.

[0014] With this configuration, the pair of arms can be easily opened and closed by operating the operating portion.

[0015] (5) In the medical device described in (4) above, the operating portion may move the outer rod in the axial direction relative to the inner rod.

[0016] With this configuration, by operating the operating portion, the outer rod can be easily moved in the axial direction relative to the inner rod.

[0017] (6) In the medical device described in (3) above, when the outer rod is moved from the second position toward the tip relative to the inner rod in the open state of the arm portions, the arm portions may be in a closed state in which the tips of the pair of arm portions rotate in a direction approaching each other, with the support portion of the support structure as a fulcrum.

[0018] With this configuration, when the arm portion is removed from the living body after treatment, the arm portion can be closed and removed in a compact state.

[0019] (7) In the medical device described in (3) above, the outer rod may have a slit portion that opens to the distal end surface of the outer rod and extends from the distal end surface toward the proximal end, and when at least the proximal ends of the pair of arm portions are accommodated in the arm accommodating space of the outer rod, a protrusion provided on the support structure may be inserted into the slit portion, and when the arm portions are placed in the open state by moving the outer rod in the proximal end direction relative to the inner rod, the protrusion on the support structure may be released from the slit portion.

[0020] With this configuration, when the outer rod and the inner rod are moved relative to each other in the axial direction by operating the operating portion, the support structure can be guided in the axial direction of the outer rod by the slit portion.

[0021] (8) In the medical device described in (7) above, the support structure may include a first support member provided at the tip of the inner rod, a second support member provided so as to be movable relative to the first support member in the axial direction, and a protrusion provided on the outer wall of the second support member and protruding radially outward, and after the entire pair of arm portions protrude from the tip opening of the outer rod and the pair of arm portions are in an open state, when the outer rod is moved in the tip direction relative to the inner rod with the protrusion and the tip surface of the outer rod facing each other in the axial direction, the protrusion abuts against the tip of the outer rod, and the second support member moves relative to the first support member in the tip direction, thereby closing the pair of arm portions.

[0022] With this configuration, the pair of arm portions can be protruded in the tip direction from the tip of the outer rod, and then the tip of the outer rod can be pressed against the protrusion, thereby moving the second support member in a direction away from the first support member and closing the arm portions.

[0023] (9) In the medical device described in (2) above, the support structure may include a first support member provided at the tip of the inner rod, a second support member provided so as to be movable relative to the first support member in the axial direction, a protrusion provided on the outer wall of the second support member protruding radially outward, and an arm lock portion that releasably restricts the opening and closing movement of the arm portions when the pair of arm portions is in an open state, and the arm lock portion may include a first suction member provided on the first support member and a second suction member provided on the second support member and capable of being adsorbed to the first suction member, and when the pair of arm portions is in an open state, the first suction member and the second suction member are adsorbed to each other, and relative movement between the first support member and the second support member in the axial direction may be restricted.

[0024] With this configuration, the arm lock portion effectively maintains the pair of arms in an open state.

[0025] (10) In the medical device described in (9) above, the outer rod may have a slit portion that opens to the distal end surface of the outer rod and extends from the distal end surface in a proximal direction, and in a first position where the pair of arm portions are in a closed state, the protrusion is inserted into the slit portion of the outer rod, and in a second position where the arm portions are in an open state, the protrusion is released from the slit portion and positioned distal to the distal end surface of the outer rod, and when the outer rod moves distally from the second position relative to the inner rod with the protrusion and the distal end surface of the outer rod facing each other in the axial direction, the protrusion may come into contact with the distal end surface of the outer rod and push the protrusion in the distal direction, thereby releasing the suction state between the first suction member and the second suction member.

[0026] With this configuration, when storing the arm portion in the outer rod after surgery, the open state of the arm portion set by the arm lock portion can be released and closed by bringing the tip of the outer rod into contact with the protrusion. The user can recognize that the tip of the outer rod has come into contact with the protrusion, and can effectively confirm that the arm portion has been stored in the arm storage space of the outer rod.

[0027] (11) In the medical device described in (9) above, at least one of the first attraction member and the second attraction member may be a magnet.

[0028] With this configuration, by configuring at least one of the first attraction member and the second attraction member from a magnet, it is possible to effectively restrict the relative movement of the first support member and the second support member.

[0029] (12) In the medical device described in (2) above, a movable mechanism is provided at the tip of the inner rod and supports the support structure so that it can tilt relative to the tip of the inner rod, and the movable mechanism may be a joint structure that includes a spherical engaging protrusion provided on either the support structure or the inner rod, and an engaging recess provided on the other of the support structure or the inner rod and with which the engaging protrusion is rotatably engaged.

[0030] With this configuration, the movable mechanism tilts the support structure at the tip of the inner rod, thereby allowing the pair of arms to effectively abut against the desired abutment site on the organ.

[0031] (13) In the medical device described in (12) above, a rotation lock portion may be provided that restricts the rotational movement of the support structure relative to the inner rod by the movable mechanism, and the rotation lock portion may include a locking member that prevents the rotation of the engaging convex portion relative to the engaging recess by biasing the engaging recess and the engaging convex portion in a direction that brings them closer to each other.

[0032] With this configuration, the pair of arms are tilted relative to the tip of the inner rod by the movable mechanism so that they abut against the abutment area of ​​the organ, and the rotational movement of the support structure is locked by the locking member of the rotation lock section, thereby effectively maintaining the abutment state of the arms against the abutment area of ​​the organ.

[0033] (14) In the medical device described in (1) above, the tip of the arm portion may have a curved portion that is curved so as to be convex toward the tip.

[0034] This configuration reduces the insertion resistance and burden on the living body when the arm portion is inserted into the living body.

[0035] According to the present invention, in a medical device that suppresses movement of the surface of an organ by contacting it with the organ of a living body, the device includes a pair of openable and closable arms supported by a shaft and equipped with a pair of suction parts that suction the organ. This allows the pair of arms to be inserted into the living body through an opening in the living body when the pair of arms is closed. Therefore, unlike a structure in which a cap is removed from the tip of the shaft and a stabilizer is attached to the tip of the shaft inside the living body, it is possible to prevent the cap from falling into the surgical field.

[0036] FIG. 1 is an explanatory diagram showing a state in which a medical device according to an embodiment of the present invention is in use. FIG. 2 is a plan view of the medical device of FIG. 1. FIG. 3 is an external perspective view showing the distal end of the medical device. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a plan view showing the initial state of the medical device with the first and second arm sections housed. FIG. 6 is an exploded perspective view of the distal end of the medical device shown in FIG. 3. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 2. FIG. 8 is an explanatory diagram of the support structure of the first and second arm sections in an open state. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 5. FIG. 10 is an explanatory diagram of the support structure of the first and second arm sections in a closed state. FIG. 11 is a plan view showing a state in which the outer rod of the medical device shown in FIG. 5 has been moved in the proximal direction. FIG. 12 is a perspective view showing a state in which portions of the first and second arm sections are housed in the outer rod. FIG. 13 is a plan view showing the distal end of the medical device of FIG. 12.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a medical device according to the present invention will be described below with reference to the accompanying drawings.

[0038] 1, the medical device 10 according to this embodiment is a stabilizer that is brought into contact with an organ (e.g., a heart 300) of a human body (hereinafter, referred to as living body P) to hold the heart 300 in a desired position and to suppress movement of the surface of the heart 300. As shown in Fig. 1, during thoracotomy (e.g., coronary artery bypass surgery), the distal end of the medical device 10 is incised adjacent to an incision 302 in the living body P and inserted into the living body through an opening 304 that is smaller than the incision 302.

[0039] As shown in FIG. 2 , the medical device 10 includes a shaft 12 , first and second arm portions 141 and 142 , and an operating portion 16 .

[0040] The shaft 12 is inserted into a living body (see FIG. 1). The shaft 12 includes an outer rod 18, an inner rod 20, and a support structure 22 that supports the first and second arm portions 141, 142 so that they can open and close.

[0041] As shown in FIG. 3 , the outer rod 18 is formed in a cylindrical shape having an inner cavity 181 (see FIG. 3 ). The outer rod 18 is provided with a tip opening 182, a slit portion 24, and a base end opening 183. The tip opening 182 opens at the tip of the outer rod 18. The tip opening 182 and the inner cavity 181 are in communication. The slit portion 24 opens at a tip end surface 184 of the outer rod 18. The slit portion 24 extends from the tip end surface 184 of the outer rod 18 in the base end direction. As shown in FIG. 4 , the slit portion 24 penetrates the outer wall of the outer rod 18 in the thickness direction. A pair of slit portions 24 are provided circumferentially spaced apart from each other on the outer rod 18. Note that the number of slit portions 24 is not limited to a pair. It is sufficient that one or more slit portions 24 are provided.

[0042] As shown in Fig. 4, the tip end of the outer rod 18 has an arm accommodating space 26. The arm accommodating space 26 is part of the inner cavity 181 at the tip end of the outer rod 18. As shown in Fig. 5, when the first and second arm portions 141, 142 are in a closed state, the arm accommodating space 26 can accommodate at least the base ends of the first and second arm portions 141, 142.

[0043] As shown in Fig. 4, the inner rod 20 is inserted into the inner cavity 181 of the outer rod 18. The inner rod 20 and the outer rod 18 are relatively movable in the axial direction of the outer rod 18. The inner rod 20 includes a cylindrical first rod 201 and a cylindrical second rod 202. The length of the first rod 201 along the axial direction is longer than the length of the outer rod 18 along the axial direction. The base end of the first rod 201 is positioned further proximally than the base end of the outer rod 18 (see Fig. 2).

[0044] As shown in FIG. 2 , a collar member 28 is provided on the first rod 201. The collar member 28 is formed in an annular shape that covers the outer periphery of the first rod 201. The collar member 28 is provided so as to be movable in the axial direction relative to the first rod 201. When the inner rod 20 is inserted into the inner cavity 181 of the outer rod 18, the collar member 28 is positioned in a proximal direction relative to the proximal end of the outer rod 18. A proximal end of a connecting member 30 is connected to the collar member 28. The connecting member 30 is, for example, a wire member. The collar member 28 and the support structure 22 are connected by the connecting member 30. The connecting member 30 is inserted into the inner cavity 181 of the outer rod 18.

[0045] As shown in FIG. 5, when the base ends of the first and second arm portions 141, 142 are accommodated in the arm accommodating space 26, the base end of the outer rod 18 and the collar member 28 are spaced apart in the axial direction.

[0046] The second rod 202 is inserted into the first rod 201. The diameter of the second rod 202 is smaller than the diameter of the first rod 201. The length of the second rod 202 along the axial direction is longer than the length of the first rod 201 along the axial direction. The base end of the second rod 202 is positioned further proximally than the base end of the first rod 201 (see FIG. 2 ).

[0047] As shown in FIG. 2 , the support structure 22 is provided at the tip of the inner rod 20. The support structure 22 supports the first and second arm portions 141, 142 so that they can open and close. The support structure 22 includes a first support member 32, a second support member 34, and an arm lock portion 36. As shown in FIG. 5 , when portions of the first and second arm portions 141, 142 are housed in the arm housing space 26 of the outer rod 18, the support structure 22 is housed in the inner cavity 181 of the outer rod 18. As shown in FIG. 2 , when the first and second arm portions 141, 142 are disposed in the distal direction from the tip of the outer rod 18, the support structure 22 is exposed from the tip of the outer rod 18.

[0048] The first support member 32 is provided at the tip end portion of the inner rod 20. As shown in FIG. 6 , the first support member 32 includes a base portion 321 and a pair of support pieces 322 that protrude in the tip direction relative to the base portion 321. The base portion 321 is provided at the base end portion of the first support member 32. The base portion 321 is disk-shaped and perpendicular to the axial direction of the first support member 32. The base portion 321 has a first accommodating portion 323. The first accommodating portion 323 is a hole that opens in the tip surface of the base portion 321 facing in the tip direction. A plurality of first accommodating portions 323 are provided spaced apart in the circumferential direction of the base portion 321.

[0049] The outer peripheral surface of the base portion 321 has grooves 324 recessed radially inward. The grooves 324 extend in the axial direction of the base portion 321. A plurality of grooves 324 are provided spaced apart in the circumferential direction of the base portion 321. The connecting member 30 is inserted into the grooves 324 (see FIG. 5 ).

[0050] The pair of support pieces 322 are formed parallel to the axial direction of the first support member 32. The pair of support pieces 322 face each other and are parallel. Each support piece 322 includes a first pin groove 381 and a first pin hole 401. The first pin groove 381 extends from the distal end of the support piece 322 toward the proximal end. The first pin hole 401 is disposed at a distance from the proximal end of the first pin groove 381 in the proximal end direction. Each first pin groove 381 and each first pin hole 401 penetrates the support piece 322 in the thickness direction. A first pin member 421 is inserted into each first pin hole 401. The first pin member 421 is supported by the pair of support pieces 322 while inserted into the first pin hole 401. A second pin member 422 is inserted into each first pin groove 381.

[0051] As shown in FIG. 2 , the second support member 34 is movable relative to the first support member 32 in the axial direction of the inner rod 20 .

[0052] 6 , the second support member 34 includes an annular portion 341, a pair of protruding portions 342 extending distally from the annular portion 341, and a pair of protrusions 343. The annular portion 341 is provided at the base end of the second support member 34. The annular portion 341 has an annular shape centered on the axis of the second support member 34. The distal end of the connecting member 30 is connected to the base end of the annular portion 341. The annular portion 341 is disposed distally relative to the base portion 321 of the first support member 32.

[0053] The base end of the annular portion 341 has second accommodating portions 344. The second accommodating portions 344 are recessed portions that are recessed from the base end of the annular portion 341 toward the tip end. A plurality of second accommodating portions 344 are provided spaced apart in the circumferential direction of the annular portion 341. As shown in FIG. 7 , the first accommodating portions 323 and the second accommodating portions 344 face each other in the circumferential direction of the first and second support members 32, 34. The number of first accommodating portions 323 and the number of second accommodating portions 344 are the same.

[0054] As shown in FIG. 6 , the pair of overhanging portions 342 are formed parallel to the axial direction of the second support member 34. The pair of overhanging portions 342 are arranged parallel to and facing each other. The overhanging portion 342 includes a second pin hole 402 and a second pin groove 382. The second pin hole 402 is arranged at the tip portion of the overhanging portion 342. The second pin groove 382 is arranged further proximally than the second pin hole 402. The second pin groove 382 extends along the axial direction of the second support member 34. Each second pin hole 402 and each second pin groove 382 penetrates the overhanging portion 342 in the thickness direction.

[0055] The inner surface of each protruding portion 342 has a guide groove 345 recessed radially outward. The guide groove 345 is provided at a position facing the second pin groove 382 and the second pin hole 402. The support piece 322 of the first support member 32 is inserted into the guide groove 345 (see FIG. 7 ). When the first support member 32 and the second support member 34 move relative to each other in the axial direction, the support piece 322 is guided along the guide groove 345.

[0056] 8 , in a plan view of the medical device 10, the first pin holes 401 and the second pin grooves 382 are arranged in the same position, and the first pin grooves 381 and the second pin holes 402 are arranged in the same position. Ends of the second pin members 422 inserted into the first pin grooves 381 of the first support member 32 are inserted into the second pin holes 402 of each protruding portion 342. Ends of the first pin members 421 inserted into the first pin holes 401 of the first support member 32 are inserted into each second pin groove 382.

[0057] As shown in Fig. 6, a pair of protrusions 343 are provided on the outer peripheral surface of the annular portion 341. The protrusions 343 protrude outward from the outer peripheral surface of the annular portion 341. The protrusions 343 extend from the base end of the second support member 34 (annular portion 341) toward the tip end. The pair of protrusions 343 are spaced apart in the circumferential direction of the annular portion 341 (see Fig. 7).

[0058] 9 , with the base ends of the first and second arm portions 141, 142 housed in the arm housing space 26 of the outer rod 18, the protrusion 343 provided on the support structure 22 is inserted into the slit portion 24. When the first and second arm portions 141, 142 are housed, the protrusion 343 is inserted into the slit portion 24, thereby preventing contact between the protrusion 343 and the outer wall (tip surface 184) of the outer rod 18.

[0059] 2, when the first and second arm portions 141, 142 are in an open state, the arm lock portion 36 releasably restricts the opening and closing movement of the first and second arm portions 141, 142. As shown in Fig. 6, the arm lock portion 36 includes a first suction member 441 provided on the first support member 32 and a second suction member 442 provided on the second support member 34 and capable of being attracted to the first suction member 441.

[0060] The first attraction member 441 has a plurality of first magnets M1. The plurality of first magnets M1 are housed in the first housing portion 323 of the first support member 32. The first magnets M1 are exposed in the first housing portion 323 in the distal end direction.

[0061] The second attraction member 442 has a plurality of second magnets M2. The plurality of second magnets M2 are housed in the second housing portion 344 of the second support member 34. The second magnets M2 are exposed in the second housing portion 344 in the proximal direction.

[0062] 2, when the first support member 32 and the second support member 34 move toward each other and the first and second arm portions 141, 142 are open, the first magnet M1 and the second magnet M2, which face each other, come into contact with each other due to magnetic force. When the base portion 321 of the first support member 32 and the annular portion 341 of the second support member 34 are in contact with each other, relative movement between the first support member 32 and the second support member 34 in the axial direction is restricted.

[0063] The first and second attraction members 441, 442 are not limited to being composed of the first and second magnets M1, M2. At least one of the first and second attraction members 441, 442 may be a magnet. For example, one of the first and second attraction members 441, 442 may be a magnet, and the other of the first and second attraction members 441, 442 may be a metal member. Furthermore, the first and second attraction members 441, 442 are not limited to being composed of magnets. For example, at least one of the first and second attraction members 441, 442 may be an attraction structure (such as a suction cup) that can attract the first support member 32 and the second support member 34 to each other in the axial direction.

[0064] 4, the tip end of the inner rod 20 is further provided with a movable mechanism 46. The movable mechanism 46 supports the support structure 22 so that it can tilt relative to the tip end of the inner rod 20. The movable mechanism 46 is a joint structure 461 that includes an engaging protrusion 48 provided on the support structure 22 and an engaging recess 50 with which the engaging protrusion 48 is rotatably engaged.

[0065] The engaging protrusion 48 is provided at the base end of the first support member 32. The engaging protrusion 48 is spherical and protrudes in the base end direction from the base portion 321. The engaging recess 50 includes a first ball support portion 521 and a second ball support portion 522 that support the engaging protrusion 48.

[0066] The first ball support portion 521 is provided at the tip of the first rod 201. The first ball support portion 521 has an open end portion 54 that opens toward the tip. The open end portion 54 of the first rod 201 can be deformed radially outward via a notch (not shown). A portion of the engaging protrusion 48 of the support structure 22 is inserted into the open end portion 54. When the engaging protrusion 48 is inserted into the open end portion 54, the base end side of the engaging protrusion 48 is held rotatably relative to the open end portion 54.

[0067] The second ball support portion 522 is provided at the tip of the second rod 202. The second ball support portion 522 is formed in a cylindrical shape that covers the first ball support portion 521 and the engaging protrusion 48. The second ball support portion 522 has an engaging recess 50. The engaging recess 50 is provided inside the second ball support portion 522. The inner surface of the second ball support portion 522 is a substantially spherical surface that can abut against the circumferential surface of the engaging protrusion 48. The tip side of the engaging protrusion 48 is held in the engaging recess 50. The engaging protrusion 48 is rotatably held between the second ball support portion 522 and the open end 54 of the first ball support portion 521.

[0068] That is, the movable mechanism 46 of the inner rod 20 supports the support structure 22 rotatably relative to the tip of the inner rod 20. The rotation range of the support structure 22 is 360° around the axis of the inner rod 20.

[0069] Note that the configuration is not limited to the one in which the engaging protrusion 48 of the movable mechanism 46 is provided on the support structure 22 and the engaging recess 50 is provided on the tip end of the inner rod 20. For example, the tip end of the inner rod 20 may be provided with an engaging protrusion 48 that protrudes in the tip direction, and the base end of the support structure 22 may be provided with an engaging recess 50 that can engage with the engaging protrusion 48.

[0070] As shown in Fig. 2, the first and second arm portions 141, 142 constitute the distal end of the medical device 10. The first and second arm portions 141, 142 are supported by the shaft 12 so as to be openable and closable. Each of the first and second arm portions 141, 142 includes a pair of suction portions 58 that suction-hold the heart 300 (see Fig. 1), a pair of rods 60 that support the suction portions 58, and an arm holder 62 that holds the rods 60. In a plan view of the medical device 10 shown in Fig. 2, the first arm portion 141 and the second arm portion 142 are symmetrically shaped and arranged symmetrically with respect to the axis L of the outer rod 18.

[0071] 4, the first arm portion 141 and the second arm portion 142 are disposed in the up-down direction centered on the axis L of the outer rod 18. Below, a case will be described in which the first arm portion 141 is disposed below the axis L of the outer rod 18 and the second arm portion 142 is disposed above the axis L of the outer rod 18.

[0072] As shown in FIG. 2 , each suction portion 58 is provided at the tip of each of the first and second arm portions 141 and 142. Each suction portion 58 has a shape that is narrower in width than in length. The suction portion 58 is gradually widened from the base end toward the tip. The tip of each suction portion 58 includes a curved portion 64 that curves convexly toward the tip. Each suction portion 58 has a contact surface 66 that contacts the surface of the heart 300 (see FIG. 1 ). The contact surface 66 is flat and has multiple suction ports 68. The multiple suction ports 68 are arranged along the longitudinal direction of the suction portion 58. Each of the multiple suction ports 68 is connected to a suction source (not shown) via a tube 70 attached to the suction portion 58. Vacuum fluid is supplied from the suction source to each suction port 68 through the tube 70. Note that only one suction port 68 may be provided.

[0073] The rod 60 is provided along the longitudinal direction of the suction portions 58 of the first and second arm portions 141, 142. The tip end of the rod 60 is inserted into and connected to the suction portions 58. The base end of the rod 60 is connected to the arm holder 62. The suction portions 58 are provided rotatable relative to the rod 60 around the axis of the rod 60.

[0074] 6, the arm holder 62 is provided at the base ends of the first and second arm portions 141, 142. The arm holder 62 of the first arm portion 141 and the arm holder 62 of the second arm portion 142 are disposed between a pair of support pieces 322 of the first support member 32 (see FIG. 4).

[0075] The base end of the rod 60 is inserted into the arm holder 62. The base end of the rod 60 is inserted so as to fit along the side surface of the arm holder 62. The extending direction of the rod 60, the side surface of the arm holder 62, and the extending direction of the suction portion 58 are substantially parallel. The base end of the arm holder 62 has a holder hole 621, and as shown in FIG. 8, a first pin member 421 of the support structure 22 is inserted into the holder hole 621. The holder hole 621 penetrates the arm holder 62 in the thickness direction of the arm holder 62. The arm holder 62 is rotatable around the first pin member 421 supported by the support piece 322 of the first support member 32 as a fulcrum. As shown in FIG. 6, the arm holder 62 further has a holder groove 622. The holder groove 622 is positioned distally of the holder hole 621. The holder groove 622 penetrates the arm holder 62 in the thickness direction and is inclined from the holder hole 621 toward the side surface toward the tip. That is, the holder groove 622 is inclined with respect to the side surface of the arm holder 62. The second pin members 422 of the support structure 22 are inserted into the holder grooves 622. As shown in Figure 8, the second pin members 422 inserted into the holder grooves 622 of the arm holder 62 are inserted into each first pin groove 381.

[0076] In a plan view of the medical device 10, the holder groove 622 of the arm holder 62 in the first arm section 141 and the holder groove 622 of the arm holder 62 in the second arm section 142 intersect with each other. The holder grooves 622 intersect symmetrically with respect to the first and second pin grooves 381, 382. The first pin hole 401, the holder hole 621, and the second pin groove 382 are arranged in the same position, and the first pin groove 381, the holder groove 622, and the second pin hole 402 are arranged in the same position.

[0077] As shown in Figure 5, at a first position where the outer rod 18 has moved toward the tip relative to the inner rod 20, the tips of the first and second arm portions 141, 142 have rotated in directions approaching each other with the first pin member 421 of the support structure 22 as a fulcrum, thereby placing the first and second arm portions 141, 142 in a closed state.

[0078] As shown in Figure 2, at a second position where the outer rod 18 is moved in the base end direction relative to the inner rod 20, the first and second arm portions 141, 142 are in an open state, with the tips of the first and second arm portions 141, 142 rotated away from each other with the first pin member 421 of the support structure 22 as a fulcrum.

[0079] The medical device 10 further includes a rotation lock portion 72 that restricts the rotation of the support structure 22 relative to the distal end of the inner rod 20 by the movable mechanism 46. As shown in FIG. 4 , the rotation lock portion 72 includes a locking member 721. The locking member 721 biases the engaging recess 50 and the engaging protrusion 48 in directions that bring them closer to each other in the axial direction of the inner rod 20, thereby preventing the engaging protrusion 48 from rotating relative to the engaging recess 50. The locking member 721 is a second ball support portion 522. The locking member 721 is movable in the axial direction by the second rod 202.

[0080] The rotation locking portion 72 has a movement restricting portion 74 that restricts relative movement between the first rod 201 and the second rod 202 that has the locking member 721. The movement restricting portion 74 has a first threaded portion 741 that is provided on the inner circumferential surface of the first rod 201, and a second threaded portion 742 that is formed on the outer circumferential surface of the second rod 202 and that is screwed into the first threaded portion 741.

[0081] By rotating the first rod 201 and the second rod 202 relative to each other, the second rod 202 can be moved axially relative to the first rod 201. When the second rod 202 is moved proximally relative to the first rod 201, the engaging recess 50 pushes the engaging protrusion 48 toward the distal end of the first rod 201. When the engaging protrusion 48 is clamped between the locking member 721 and the distal end of the first rod 201, the rotation of the first rod 201 and the support structure 22 by the movable mechanism 46 is restricted, and a locked state is established in which rotation of the first and second arm portions 141, 142 including the support structure 22 is prevented. Note that the medical device 10 is not limited to a configuration including the rotation lock portion 72. For example, the support structure 22 and the first and second arm portions 141, 142 may be brought into contact with the surface of the heart 300 while remaining rotatable, without providing the rotation lock portion 72.

[0082] The operating unit 16 is provided at the base end of the shaft 12. The operating unit 16 has a housing 16A, a first operating member 161, and a second operating member 162. The housing 16A is cylindrical, and the base end of the shaft 12 is inserted into it. A slide groove 16B is formed on the outer surface of the housing 16A. The slide groove 16B is provided at the tip end of the housing 16A. The slide groove 16B extends in the axial direction of the housing 16A. Inside the housing 16A, the inner rod 20 is fixed to a fixing portion 16C. The first operating member 161 is operated by a user to open and close the first and second arm portions 141, 142. A portion of the first operating member 161 is disposed outside the housing 16A. A portion of the first operating member 161 is inserted into the slide groove 16B and is connected to the base end of the outer rod 18 through the slide groove 16B. When the user operates the first operating member 161, the first operating member 161 moves along the slide groove 16B, and moves the outer rod 18 in the axial direction relative to the inner rod 20. By moving the first operating member 161 in the axial direction relative to the inner rod 20, the outer rod 18 can be moved in the axial direction.

[0083] The second operating member 162 can rotate the second rod 202 relative to the first rod 201. The second operating member 162 is a rotating body rotatably provided at the base end of the housing 16A. The center of the second operating member 162 is fixed to the second rod 202. The second operating member 162 and the second rod 202 can rotate integrally. When a user operates the second operating member 162, the second rod 202 rotates relative to the first rod 201 around the axis of the second rod 202. It should be noted that the medical device 10 is not limited to a configuration including the operating unit 16. For example, a user may grasp the outer rod 18 and manually move the outer rod 18 axially relative to the inner rod 20.

[0084] Next, a method of using the medical device 10 will be described.

[0085] As shown in Figure 5, the medical device 10 before use (initial state) is in a first position where the outer rod 18 has moved toward the tip relative to the inner rod 20, and is in a closed state where the tips of the first and second arm portions 141, 142 have rotated toward each other with the first pin member 421 of the support structure 22 as a fulcrum, and the base ends of the first and second arm portions 141, 142 are accommodated in the arm accommodating space 26 of the outer rod 18.

[0086] First, the distal end of the medical device 10 is inserted through an opening 304 made adjacent to the incision 302 in the living body P shown in Fig. 1 . After the distal end of the medical device 10 is inserted to a desired position in the heart 300 (organ) inside the living body, the user operates the first operating member 161 of the operating unit 16 to pull the outer rod 18 in the proximal direction relative to the inner rod 20. As shown in Fig. 11 , as the outer rod 18 moves in the proximal direction, the first and second arm portions 141, 142 and the support structure 22 are exposed in the distal direction of the outer rod 18. At this time, until the proximal end of the outer rod 18 abuts against the collar member 28 (see Fig. 2 ), the first support member 32 and the second support member 34 are spaced apart in the axial direction, and the first and second arm portions 141, 142 are maintained in a closed state.

[0087] Further operation of the first operating member 161 moves the outer rod 18 further in the proximal direction relative to the inner rod 20 to the second position, as shown in Figure 4. At the second position, the proximal end of the outer rod 18 abuts against the collar member 28 and pushes the collar member 28 in the proximal direction. As the collar member 28 moves in the proximal direction together with the outer rod 18, the connecting member 30 is pulled in the proximal direction together with the collar member 28. The second support member 34 connected to the connecting member 30 moves toward the first support member 32. At this time, the first support member 32 does not move in the proximal direction.

[0088] In this second position, as shown in FIG. 8 , the first and second arm sections 141, 142 are in an open state, with the tips of the first and second arm sections 141, 142 pivoting away from each other around the first pin member 421 of the support structure 22 as a fulcrum. Specifically, as the second support member 34 moves toward the proximal end, the second pin member 422 moves toward the proximal end along the first pin groove 381 of the support piece 322, and the second pin member 422 moves toward the proximal end in the holder groove 622. As a result, the proximal end of the arm holder 62 of the first arm section 141 and the proximal end of the arm holder 62 of the second arm section 142 pivot toward each other around the first pin member 421 as a fulcrum. The tip of the first arm section 141 and the tip of the second arm section 142 pivot away from each other. The medical device 10 is in an open state in which the first arm portion 141 and the second arm portion 142 are spaced apart by a predetermined angle. In the plan view of the medical device 10 shown in Figure 2, the first arm portion 141 and the second arm portion 142 open in a V-shape so that the distance between the first arm portion 141 and the second arm portion 142 increases toward the distal end.

[0089] At this time, the annular portion 341 of the second support member 34 abuts against the base portion 321 of the first support member 32, causing the first magnet M1 and the second magnet M2 to come into contact with each other due to magnetic force. Relative movement in the axial direction between the first support member 32 and the second support member 34 is restricted, and the first and second arm portions 141, 142 are maintained in the open state.

[0090] The movable mechanism 46 allows the support structure 22 to rotate freely relative to the inner rod 20, and then the abutment surfaces 66 of the suction portions 58 of the first and second arm portions 141, 142 are brought into contact with the surface of the heart 300. When the first and second arm portions 141, 142 abut against the surface of the heart 300, the movable mechanism 46 causes the first and second arm portions 141, 142 to change their posture so that they move along the surface. At this time, the support structure 22 rotates in the circumferential direction relative to the tip of the inner rod 20. The suction portions 58 of the first arm portion 141 and the second arm portion 142 press against the surface of the heart 300. By rotating each suction portion 58 relative to the rod 60, the abutment surfaces 66 of each suction portion 58 can be brought into closer contact with the surface of the heart 300.

[0091] After the first and second arm portions 141, 142 are brought into contact with the surface of the heart 300, the user operates the second operating member 162 of the operating unit 16, thereby causing the rotation lock portion 72 to restrict the rotation of the support structure 22 by the movable mechanism 46. By rotating the second rod 202 via the second operating member 162, the first threaded portion 741 and the second threaded portion 742 are threadedly engaged with each other, causing the second rod 202 to move in the proximal direction relative to the first rod 201. The engaging recess 50 pushes the engaging protrusion 48 of the first support member 32 toward the tip of the first rod 201. The engaging protrusion 48 is clamped between the lock member 721 and the tip of the first rod 201. The rotation of the first rod 201 and the support structure 22 by the movable mechanism 46 is restricted, and a locked state is established in which rotation of the first and second arm portions 141, 142, including the support structure 22, is prevented. That is, the rotation of the first and second arm portions 141, 142 is prevented with the contact surfaces 66 of the first and second arm portions 141, 142 in contact with the surface of the heart 300. This fixes the orientation of the first and second arm portions 141, 142 relative to the shaft 12.

[0092] Negative pressure fluid is supplied from a suction source (not shown) through a tube 70 to each suction port 68 of the first and second arm portions 141, 142. The negative pressure fluid supplied to the suction port 68 causes the suction portions 58 of the first and second arm portions 141, 142 to suck the surface of the heart 300. At the distal end of the medical device 10, movement of the surface of the heart 300 due to pulsation is suppressed.

[0093] After the thoracotomy on the living body P is completed, the medical device 10 is removed from the living body. After the supply of negative pressure fluid to the suction portion 58 is stopped, the second operating member 162 of the operating unit 16 is rotated in the opposite direction to that used to lock the rotation lock portion 72, thereby releasing the locked state of the movable mechanism 46 by the rotation lock portion 72. The rotation of the second rod 202 moves the engagement recess 50 away from the engagement protrusion 48, allowing the engagement protrusion 48 to rotate between the engagement recess 50 and the tip of the first rod 201.

[0094] Next, the user moves the outer rod 18 in the distal direction relative to the inner rod 20 using the first operating member 161. At this time, as shown in Fig. 12, the slit portion 24 of the outer rod 18 and the protrusion 343 of the second support member 34 are positioned at positions that are offset in the circumferential direction of the shaft 12 when viewed from the axial direction of the shaft 12. Therefore, the protrusion 343 and the distal end surface 184 of the outer rod 18 face each other. This is because the first and second arm portions 141, 142 are rotated by the movable mechanism 46, and the support structure 22 rotates in the circumferential direction relative to the outer rod 18 together with the first and second arm portions 141, 142, causing the protrusion 343 and the slit portion 24 to be offset in the circumferential direction.

[0095] As shown in Fig. 12, the tip of the outer rod 18 comes into contact with the protrusion 343 of the second support member 34. When the outer rod 18 is further moved in the tip direction, the tip surface 184 of the outer rod 18 presses the protrusion 343 in the tip direction, causing the second support member 34 to move in the tip direction relative to the first support member 32. With this movement of the second support member 34, as shown in Fig. 13, the first magnet M1 and the second magnet M2 move away from each other, and the restriction on the movement of the second support member 34 relative to the first support member 32 is released. In other words, when the first and second arm portions 141, 142 are in the open state, the restriction on the opening and closing of the first and second arm portions 141, 142 by the arm lock portion 36 is released.

[0096] Due to the relative movement of the second support member 34 toward the distal end with respect to the first support member 32, the distal ends of the first and second arm portions 141, 142 rotate about the first pin member 421 as a fulcrum so as to approach each other. The first and second arm portions 141, 142 close to a closed state. The base ends of the first and second arm portions 141, 142 are accommodated in the arm accommodating space 26 through the distal end opening 182 of the outer rod 18. Note that, when viewed from the axial direction of the shaft 12, if the slit portion 24 of the outer rod 18 and the protrusion 343 of the second support member 34 are aligned in the circumferential direction of the shaft 12, the protrusion 343 moves toward the proximal end along the slit portion 24, so that the proximal ends of the first and second arm portions 141, 142 are accommodated in the distal end opening 182 of the outer rod 18, and the rods 60 of the first and second arm portions 141, 142 abut against the inner wall of the outer rod 18, thereby being accommodated in a closed state.

[0097] With the first and second arm portions 141 and 142 closed, the distal end of the medical device 10 is removed to the outside of the living body P through the opening 304 .

[0098] This embodiment has the following advantages.

[0099] As shown in Figure 1, the medical device 10 comprises a shaft 12 to be inserted into a living body P, and first and second arm portions 141, 142 that are openable and closable and supported by the shaft 12 and have a pair of suction portions 58 that suction the heart 300 (organ), and the first and second arm portions 141, 142 form the tip portion of the medical device 10.

[0100] As a result, the first and second arm units 141, 142 can be opened and closed, and therefore, with the first and second arm units 141, 142 closed, the first and second arm units 141, 142 can be inserted into the living body P through the opening 304 provided in the living body P. Therefore, unlike a structure in which a cap is removed from the tip of the shaft inside the living body and a stabilizer is attached to the tip of the shaft, it is possible to avoid the cap falling into the surgical field.

[0101] As shown in Fig. 2, the shaft 12 has a cylindrical outer rod 18, an inner rod 20 inserted into an inner cavity 181 of the outer rod 18, and a support structure 22 provided at the tip of the inner rod 20. The support structure 22 supports the first and second arm portions 141, 142 so that they can open and close, and as shown in Fig. 5, the outer rod 18 has an arm accommodating space 26 that can accommodate the base ends of the first and second arm portions 141, 142 when the first and second arm portions 141, 142 are closed.

[0102] As a result, the first and second arm portions 141, 142 are accommodated in the arm accommodating space 26 of the outer rod 18 in a closed state, and therefore, when the first and second arm portions 141, 142 are inserted into the living body, the insertion resistance of the first and second arm portions 141, 142 is effectively suppressed.

[0103] As shown in Figure 5, at a first position where the outer rod 18 has moved toward the tip end relative to the inner rod 20, the first and second arm portions 141, 142 are in a closed state where the tips of the first and second arm portions 141, 142 rotate in directions approaching each other, with the support portion (first pin member 421) of the support structure 22 as a fulcrum.At a second position where the outer rod 18 has moved toward the base end relative to the inner rod 20 as shown in Figure 2, the first and second arm portions 141, 142 are in an open state where the tips of the first and second arm portions 141, 142 rotate so as to move away from each other.

[0104] This allows the first and second arm portions 141, 142 to be inserted into the living body at a first position in which they are closed, and then the first and second arm portions 141, 142 to be rotated inside the living body to be in an open second position, thereby achieving both ease of insertion of the first and second arm portions 141, 142 into the living body and the ability to maintain the surface of the heart 300.

[0105] 2, an operating unit 16 (first operating member 161) is provided at the base end of the outer rod 18 and performs the opening and closing operation of the first and second arm units 141, 142. As a result, by operating the operating unit 16, the opening and closing operation of the first and second arm units 141, 142 can be easily performed.

[0106] The operating portion 16 moves the outer rod 18 in the axial direction relative to the inner rod 20. Thus, by operating the operating portion 16, the outer rod 18 can be easily moved in the axial direction relative to the inner rod 20.

[0107] As shown in Figure 2, when the first and second arm portions 141, 142 are in an open state, when the outer rod 18 is moved from the second position toward the tip relative to the inner rod 20 as shown in Figure 11, the tips of the first and second arm portions 141, 142 rotate in directions approaching each other, resulting in a closed state of the first and second arm portions 141, 142. Therefore, when the first and second arm portions 141, 142 are removed from the living body after surgery, the first and second arm portions 141, 142 can be closed and removed in a compact state.

[0108] As shown in Fig. 2, the outer rod 18 has a slit portion 24 that opens in a tip surface 184 of the outer rod 18 and extends from the tip surface 184 toward the base end. As shown in Fig. 9, with the base ends of the first and second arm portions 141, 142 housed in the arm housing space 26 of the outer rod 18, a protrusion 343 provided on the support structure 22 is inserted into the slit portion 24. When the first and second arm portions 141, 142 are opened, the protrusion 343 of the support structure 22 is released from the slit portion 24.

[0109] As a result, when the outer rod 18 and the inner rod 20 are moved relative to each other in the axial direction by operating the operating portion 16 , the support structure 22 can be guided in the axial direction of the outer rod 18 by the slit portion 24 .

[0110] 6 , the support structure 22 includes a first support member 32 provided at the tip end of the inner rod 20, a second support member 34 provided so as to be movable axially relative to the first support member 32, and a protrusion 343 provided on the outer wall of the second support member 34 and protruding radially outward. After the entire first and second arm portions 141, 142 protrude from the tip opening 182 of the outer rod 18 to be in an open state, when the outer rod 18 is moved in the tip direction relative to the inner rod 20 with the protrusion 343 and the tip face 184 of the outer rod 18 facing each other in the axial direction, the protrusion 343 comes into contact with the tip of the outer rod 18, and the second support member 34 moves in the tip direction relative to the first support member 32, thereby closing the first and second arm portions 141, 142.

[0111] 2, the support structure 22 has an arm locking portion 36 that releasably restricts the opening and closing operation of the first and second arm portions 141, 142 when the first and second arm portions 141, 142 are in an open state. The arm locking portion 36 includes a first suction member 441 provided on the first support member 32, and a second suction member 442 provided on the second support member 34 and capable of being attracted to the first suction member 441.

[0112] As a result, when the first and second arm portions 141, 142 are in the open state, the first suction member 441 and the second suction member 442 are attracted to each other, and by restricting the relative axial movement between the first support member 32 and the second support member 34, the open state of the first and second arm portions 141, 142 is effectively maintained.

[0113] 12 , when the outer rod 18 moves in the distal direction relative to the inner rod 20 from the second position in which the first and second arm portions 141, 142 are open, with the protrusion 343 and the distal end surface 184 of the outer rod 18 facing each other in the axial direction, the protrusion 343 comes into contact with the distal end surface 184 of the outer rod 18 and pushes the protrusion 343 in the distal direction. As the outer rod 18 moves, the adsorbed state between the first adsorbing member 441 and the second adsorbing member 442 is released.

[0114] As a result, when storing the first and second arm portions 141, 142 in the outer rod 18 after surgery, the open state of the first and second arm portions 141, 142 held by the arm lock portion 36 can be released and closed by bringing the tip of the outer rod 18 into contact with the protrusion 343. The user can recognize that the protrusion 343 has come into contact with the tip of the outer rod 18 without directly seeing it, and can effectively confirm that the first and second arm portions 141, 142 have been stored in the arm storage space 26 of the outer rod 18.

[0115] 6, the first attraction member 441 and the second attraction member 442 are the first and second magnets M1 and M2, respectively. By configuring the first and second attraction members 441 and 442 from the first and second magnets M1 and M2, the relative movement of the first support member 32 and the second support member 34 can be effectively restricted.

[0116] As shown in Fig. 4, the movable mechanism 46 is provided at the tip of the inner rod 20 and supports the support structure 22 rotatably relative to the tip of the inner rod 20. The movable mechanism 46 is a joint structure 461 that includes a spherical engaging protrusion 48 provided on the support structure 22 and an engaging recess 50 provided on the inner rod 20 and with which the engaging protrusion 48 is rotatably engaged.

[0117] As a result, by using the movable mechanism 46 to rotate the support structure 22 at the tip of the inner rod 20, the first and second arm portions 141, 142 can be effectively abutted against the desired abutment site on the heart 300.

[0118] The rotation lock portion 72 restricts the rotation of the support structure 22 relative to the inner rod 20 by the movable mechanism 46. The rotation lock portion 72 includes a lock member 721 that biases the engagement recess 50 and the engagement protrusion 48 in directions that bring them closer to each other, thereby preventing the engagement protrusion 48 from rotating relative to the engagement recess 50.

[0119] As a result, the first and second arm portions 141, 142 are rotated relative to the tip of the inner rod 20 by the movable mechanism 46 so that they abut against the abutment portion of the heart 300, and the rotational movement of the support structure 22 is locked by the locking member 721 of the rotation lock portion 72, thereby effectively maintaining the abutment state of the first and second arm portions 141, 142 against the surface of the heart 300.

[0120] 3, the distal ends of the first and second arm portions 141, 142 are provided with curved portions 64 that are curved so as to be convex toward the distal ends, thereby reducing the insertion resistance and burden on the living body P when the first and second arm portions 141, 142 are inserted into the living body.

[0121] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

Claims

1. A medical device that suppresses the movement of the surface of an organ by contacting the organ of a living body, the medical device comprising: a shaft inserted into the living body; and a pair of arm portions that constitute a tip portion of the medical device, have a pair of suction portions for sucking the organ, and are supported by the shaft and can be opened and closed.

2. The medical device according to claim 1, wherein the shaft has a cylindrical outer rod, an inner rod inserted into the lumen of the outer rod, and a support structure provided at the tip of the inner rod for supporting the pair of arm portions so as to be openable and closable, the outer rod and the inner rod are relatively movable in the axial direction of the outer rod, and the outer rod has an arm accommodation space capable of accommodating at least a base end portion of the pair of arm portions in a state where the pair of arm portions are closed.

3. The medical device according to claim 2, wherein in a first position where the outer rod moves in the tip direction with respect to the inner rod, a closed state of the arm portions is formed in which the tips of the pair of arm portions rotate in a direction approaching each other with the support portion of the support structure as a fulcrum, and in a second position where the outer rod moves in the base end direction with respect to the inner rod, an open state of the arm portions is formed in which the tips of the pair of arm portions rotate so as to be separated from each other with the support portion of the support structure as a fulcrum.

4. The medical device according to claim 3, further comprising an operation portion provided at a base end portion of the outer rod for performing an opening and closing operation of the pair of arm portions.

5. The medical device according to claim 4, wherein the operation portion moves the outer rod in the axial direction with respect to the inner rod.

6. The medical device according to claim 3, wherein in an open state of the arm portions, when the outer rod is moved in the tip direction with respect to the inner rod from the second position, a closed state of the arm portions is formed in which the tips of the pair of arm portions rotate in a direction approaching each other with the support portion of the support structure as a fulcrum.

7. The medical device according to claim 3, wherein the outer rod has a slit portion that opens to the front end surface of the outer rod and extends in the proximal end direction from the front end surface, and in a state where at least the proximal end portions of the pair of arm portions are accommodated in the arm accommodation space of the outer rod, a protrusion provided on the support structure is inserted into the slit portion, and the protrusion of the support structure detaches from the slit portion in a state where the arm portion is in the open state by moving the outer rod in the proximal end direction with respect to the inner rod. Medical device.

8. The medical device according to claim 7, wherein the support structure includes a first support member provided at the distal end portion of the inner rod, a second support member provided so as to be axially relatively movable with respect to the first support member, and a protrusion provided on the outer wall of the second support member and protruding radially outward. After the entire pair of arm portions protrude from the distal end opening of the outer rod and the pair of arm portions are in the open state, when the outer rod is moved in the distal end direction with respect to the inner rod in a state where the protrusion and the front end surface of the outer rod face each other in the axial direction, the protrusion abuts against the distal end of the outer rod, and the second support member moves relative to the first support member in the distal end direction, so that the pair of arm portions are in the closed state. Medical device.

9. The medical device according to claim 2, wherein the support structure includes a first support member provided at the distal end portion of the inner rod, a second support member provided so as to be axially relatively movable with respect to the first support member, a protrusion provided on the outer wall of the second support member and protruding radially outward, and an arm lock portion that can restrict the opening and closing operation of the arm portion in the open state of the pair of arm portions. The arm lock portion includes a first adsorption member provided on the first support member and a second adsorption member provided on the second support member and capable of adsorbing to the first adsorption member. In the open state of the pair of arm portions, the first adsorption member and the second adsorption member are adsorbed to each other, and the relative movement in the axial direction between the first support member and the second support member is restricted. Medical device.

10. In the medical device according to claim 9, the outer rod has a slit portion that opens at the tip surface of the outer rod and extends in the proximal direction from the tip surface. In the first position where the pair of arm portions are in the closed state, the protrusion is inserted into the slit portion of the outer rod. In the second position where the arm portions are in the open state, the protrusion is detached from the slit portion and is disposed on the tip side of the tip surface of the outer rod. When the outer rod moves in the tip direction with respect to the inner rod from the second position in a state where the protrusion and the tip surface of the outer rod face each other in the axial direction, the protrusion abuts against the tip surface of the outer rod and pushes the protrusion in the tip direction, thereby releasing the adsorption state between the first adsorption member and the second adsorption member. A medical device.

11. In the medical device according to claim 9, at least one of the first adsorption member and the second adsorption member is a magnet. A medical device.

12. In the medical device according to claim 2, a movable mechanism is provided at the tip of the inner rod and supports the support structure so as to be tiltable with respect to the tip of the inner rod. The movable mechanism includes a spherical engagement convex portion provided on either the support structure or the inner rod, and an engagement concave portion provided on the other of the support structure and the inner rod, and the engagement convex portion is rotatably engaged therewith. It is a joint structure provided with. A medical device.

13. In the medical device according to claim 12, it has a rotation lock portion that regulates the rotation operation of the support structure with respect to the inner rod by the movable mechanism. The rotation lock portion includes a lock member that prevents the rotation of the engagement convex portion with respect to the engagement concave portion by urging the engagement concave portion and the engagement convex portion in a direction approaching each other. A medical device.

14. In the medical device according to claim 1, the tip of the arm portion includes a curved portion that is curved so as to be convex toward the tip. A medical device.

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