Medical device

Abstract

This medical device (10) is provided with an operation unit (100), a first jaw (250a) and a second jaw (250b) that are provided at the distal end of a shaft member (230), and a power transmission member (300). The operation unit (100) has a first operation lever (102a) and a second operation lever (102b). When a user rotates the first operation lever (102a) and the second operation lever (102b) with respect to a casing (20), the power transmission member moves along the axial direction of the shaft member. With this movement, the first jaw and the second jaw are opened and closed.

Description

Medical Devices

[0001] The present invention relates to a medical device for harvesting biological tissue.

[0002] In coronary artery bypass surgery, a blood vessel that bypasses the diseased area is connected to the artery. This blood vessel is harvested, for example, from the patient's leg using an endoscopic blood vessel harvesting system.

[0003] The endoscopic blood vessel harvesting system includes a medical device equipped with a blood vessel harvesting instrument. The blood vessel harvesting instrument may have a configuration having first and second jaws that can be opened and closed, as described in Japanese Patent Nos. 6840749 and 6855457. In this configuration, the first and second jaws are switched from an open state to a closed state inside the patient's body, thereby clamping a blood vessel between the first and second jaws. The blood vessel harvesting instrument is then moved outside the patient's body, and the blood vessel clamped between the first and second jaws is removed from the body. In this case, the biological tissue harvested by the medical device is a blood vessel.

[0004] In the medical device disclosed in Japanese Patent No. 6840749, a casing containing an ultrasonic transducer assembly is provided with a first jaw and a first ring portion into which a user inserts their finger. Meanwhile, the second jaw and the second ring portion are provided on a shank that is rotatably connected to the casing. Therefore, when a user inserts their fingers through the first and second ring portions to open and close the first and second jaws, the shank and the casing may swing in accordance with the movement of the user's finger.

[0005] In addition, the ring portion into which the user inserts his or her finger is positioned close to the first and second jaws, so with this medical device, the first and second jaws cannot be inserted deep into the patient's body.

[0006] The medical device described in Japanese Patent No. 6855457 is capable of inserting a first jaw and a second jaw deep into a patient's body. In this medical device, the first jaw and the second jaw are opened and closed by simultaneously pushing two levers toward a cylindrical casing. This requires the user to grasp the casing and simultaneously press the two levers with two fingers, which makes it difficult to smoothly open and close the first jaw and the second jaw.

[0007] The present invention aims to solve the above-mentioned problems.

[0008] (1) One aspect of the present invention is a medical device including an operating unit operated by a user, a shaft member extending distally from the operating unit, and first and second jaws provided at the distal end of the shaft member in an openable and closable manner. The operating unit includes a casing, a first operating lever rotatable relative to the casing and having a first annular finger hook portion formed with a first finger hole through which the user inserts a finger, and a second operating lever rotatable relative to the casing and having a second annular finger hook portion formed with a second finger hole through which the user inserts a finger different from the finger inserted into the first finger hole. The first operating lever and the second operating lever face each other via the casing.

[0009] The medical device includes a power transmission member that is movable along the axial direction of the shaft member and that rotates at least one of the first jaw and the second jaw so that the first jaw and the second jaw open and close in association with the axial movement relative to the shaft member. The power transmission member moves in the axial direction relative to the shaft member in conjunction with the rotation of the first operating lever and the second operating lever relative to the casing.

[0010] The user inserts his or her fingers into the first and second operating levers and holds (grapples) the casing in the palm of his or her hand, and then moves his or her fingers to apply a rotational force to the first and second operating levers, thereby opening and closing the first and second jaws. This makes it easy for the user to apply force to their hand and move their fingers, improving the operability of the medical device.

[0011] (2) In the medical device described in the above item (1), when the first operating lever rotates so that the first finger hook approaches the casing and when the second operating lever rotates so that the second finger hook approaches the casing, the power transmission member may move toward the distal end along the axial direction of the shaft member, and the first jaw and the second jaw may be in a closed state. On the other hand, when the first operating lever rotates so that the first finger hook moves away from the casing and when the second operating lever rotates so that the second finger hook moves away from the casing, the power transmission member may move toward the proximal end along the axial direction of the shaft member, and the first jaw and the second jaw may be in an open state.

[0012] In this case, the open / closed states of the first and second operating levers match the open / closed states of the first and second jaws, so that the user can easily recognize that the first and second jaws have changed from an open state to a closed state, for example, by operating the first and second operating levers from an open state to a closed state.

[0013] (3) In the medical device described in (1) or (2), the first and second operating levers may have rotation centers provided at the base end of the casing. The first and second operating levers may rotate such that the first and second finger hooks move closer to or farther from the casing than the rotation center.

[0014] In this case, the user can easily rotate the first operating lever and the second operating lever.

[0015] (4) In the medical device described in item (1) or (2), the operating unit may include a first toggle mechanism coupled to the casing, the first operating lever, and the power transmission member, and a second toggle mechanism coupled to the casing, the second operating lever, and the power transmission member. The first toggle mechanism may have a first link and a second link rotatably coupled to each other. Here, the first link may have a first end rotatably coupled to the casing and a second end rotatably coupled to the second link, and the second link may have a third end rotatably coupled to the second end and a fourth end rotatably coupled to the power transmission member. The first operating lever may be coupled to a coupling point between the second end and the third end.

[0016] The second toggle mechanism may include a third link and a fourth link rotatably connected to each other. Here, the third link may have a fifth end rotatably connected to the casing and a sixth end rotatably connected to the fourth link, and the fourth link may have a seventh end rotatably connected to the sixth end and an eighth end rotatably connected to the power transmission member. The second operating lever may be connected to a connection point between the sixth end and the seventh end.

[0017] The power transmission member, together with the first and second links, constitutes a first toggle mechanism, and the power transmission member, together with the third and fourth links, constitutes a second toggle mechanism, so that the user can easily move the power transmission member by rotating the first and second operating levers with a small force.

[0018] (5) The medical device according to any one of items (1) to (4) above may further include a cutter for excising biological tissue. In this aspect, the operating unit may include a cutter-moving operating member on the casing for moving the cutter along the axial direction of the shaft member. The cutter-moving operating member may be located distally of the first fingerhold or the second fingerhold. Here, the casing may have a first side surface and a second side surface located on opposite sides of the axis of the casing, the first operating lever may be located on the first side surface, the second operating lever may be located on the second side surface, and the cutter-moving operating member may be located on the first side surface or the second side surface.

[0019] Since the cutter can cut the biological tissue, it is easy to collect the biological tissue. Furthermore, while holding the casing in the palm of the user's hand, the user can easily touch the cutter movement operating member with the fingers that are not inserted in the first finger hole or the second finger hole. Therefore, the user can easily move the cutter.

[0020] (6) In the medical device described in the above item (5), the cutter movement operating member may be a lever. In this aspect, one end of the lever may be connected to the casing via a support member on a distal side of the first finger hook or the second finger hook, the lever may be rotatable around the support member as a rotation center such that the other end, that is, a free end, of the lever approaches or moves away from the casing, and the cutter may move toward the distal end along the axial direction of the shaft member by rotating the lever so that the free end of the lever approaches the casing.

[0021] As described above, the user can easily touch the lever with a finger that is not inserted in either the first or second finger hole. Furthermore, one end of the lever facing the tip of the casing is connected to the casing, and the other end facing the base end of the casing is located closer to the tip of the casing than the first or second finger hook. Therefore, the user can easily rotate the lever by pushing the other end of the lever toward the casing with a finger. This allows the user to easily move the cutter.

[0022] (7) In the medical device according to any one of items (1) to (4), the first jaw and the second jaw may have a first electrode and a second electrode, respectively, for cauterizing biological tissue. In this aspect, the operation unit may have a changeover switch in the casing that switches between energizing and de-energizing the first electrode and the second electrode, the changeover switch being located distally of the first finger rest or the second finger rest, the casing having a first side surface and a second side surface that are located opposite each other with respect to an axis of the casing, the first operating lever being disposed on the first side surface, the second operating lever being disposed on the second side surface, and the changeover switch being disposed on the first side surface or the second side surface.

[0023] By passing current between the first and second electrodes, it is possible to cauterize biological tissue sandwiched between the first and second jaws. Therefore, for example, if the biological tissue is a blood vessel, it is possible to quickly stop bleeding when sampling the blood vessel. Furthermore, while holding the casing in the palm of the user's hand, the user can easily touch the selector switch with a finger that is not inserted in either the first or second finger hole. Therefore, the user can easily switch between energizing and de-energizing the first and second electrodes.

[0024] (8) In the medical device described in the above item (7), the changeover switch may be movable toward the distal end or the proximal end along the axial direction of the shaft member.

[0025] With this configuration, the user can easily switch between energizing and de-energizing the first electrode and the second electrode by moving the changeover switch along the axial direction of the casing toward the tip or base end with a finger that is not inserted in the first finger hole and is not inserted in the second finger hole.

[0026] (9) The medical device according to any one of items (1) to (4) above may include a cutter for excising biological tissue, and the first jaw and the second jaw may have a first electrode and a second electrode for cauterizing the biological tissue, respectively. In this aspect, the operation unit may include, on the casing, a changeover switch for switching between energizing and de-energizing the first electrode and the second electrode, and a cutter movement operating member for moving the cutter along the axial direction of the casing, the changeover switch may be located distally of the first finger hook or the second finger hook, and the cutter movement operating member may be located distally of the first finger hook or the second finger hook. The casing may have a first side surface and a second side surface located opposite each other with respect to an axis of the casing, the first operating lever may be located on the first side surface, the second operating lever may be located on the second side surface, the changeover switch may be located on one of the first side surface and the second side surface, and the cutter movement operating member may be located on the other of the first side surface and the second side surface.

[0027] With this configuration, the biological tissue can be excised with the cutter, making it easy to collect the biological tissue. In addition, since the biological tissue sandwiched between the first jaw and the second jaw can be cauterized, for example, if the biological tissue is a blood vessel, it is possible to quickly stop bleeding when collecting the blood vessel.

[0028] Furthermore, while holding the casing in the palm of the hand, the user can individually touch the cutter movement operating member or the selector switch with the fingers that are not inserted in the first finger hole and the second finger hole, thereby enabling the user to easily move the cutter and easily switch between energizing and deenergizing the first electrode and the second electrode.

[0029] (10) In the medical device described in any one of items (7) to (9) above, the casing may have an insertion hole at its base end for passing a first power line electrically connected to the first electrode and a second power line electrically connected to the second electrode.

[0030] The base end of the casing is a location that is not touched by the user's fingers or palm. Therefore, by passing the first power line and the second power line through the insertion holes formed in the above location, the first power line and the second power line are prevented from interfering with the user's operation of the medical device.

[0031] (11) In the medical device described in any one of items (1) to (10) above, the operating unit may have, inside the casing, a stopper located on the proximal side of the proximal end of the power transmission member that stops the movement of the power transmission member toward the proximal end of the casing.

[0032] When the power transmission member abuts against the stopper, the opening (or closing) of the first jaw and the second jaw is stopped. Therefore, for example, excessive opening of the first jaw and the second jaw is prevented, and it is easy to insert the first jaw and the second jaw into the body of a living organism.

[0033] (12) In the medical device described in any one of items (1) to (11) above, the operating section may have a coil spring inside the casing that urges the power transmission member toward the distal end.

[0034] For example, after the first and second operating levers are rotated from the closed state to the open state by the user's operation, when the user removes their fingers from the first and second finger holes, the coil springs elastically push the power transmission member, causing the first and second operating levers to change from the open state to the closed state. Therefore, the user does not need to operate the first and second operating levers to return them from the open state to the closed state.

[0035] (13) In the medical device described in the above item (11), the first jaw and the second jaw may have a first electrode and a second electrode, respectively, for cauterizing biological tissue, the stopper may have a through hole for passing a first power line electrically connected to the first electrode and a second power line electrically connected to the second electrode, and the casing may have an insertion hole, located closer to the base end than the base end of the stopper, for passing the first power line and the second power line.

[0036] With this configuration, the first power line and the second power line can be passed through the through-hole of the stopper and into the insertion hole formed on the proximal end of the stopper. Therefore, even though the stopper is provided inside the casing, the first power line and the second power line can be exposed from inside the casing to the outside.

[0037] (14) In the medical device described in any one of items (1) to (13) above, the shaft member may be hollow, and a portion of the power transmission member may be inserted inside the shaft member so as to be movable relative to the shaft member.

[0038] Since a portion of the power transmission member is inserted inside the shaft member, the medical device can be made smaller.

[0039] According to the present invention, the user can open and close the first jaw and the second jaw by moving their fingers, thereby improving the operability of the medical device.

[0040] FIG. 1 is a schematic overall side view of a medical device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the medical device. FIG. 3 is a schematic perspective view of the operating unit, with the second half of the casing not shown. FIG. 4 is an enlarged side view of the main parts of the operating unit, with the periphery of a cutter-moving operating member enlarged. FIG. 5 is an enlarged side view of the main parts of the operating unit, with the periphery of a selector switch enlarged. FIG. 6 is an enlarged perspective view of the main parts of the distal end of the medical device. FIG. 7 is an enlarged perspective view of the main parts, with the shaft member in FIG. 6 not shown. FIG. 8 is a schematic side view of the first jaw and the second jaw in an open state. FIG. 9 is a side view of the main parts of the operating unit when the first operating lever and the second operating lever are closed. FIG. 10 is an enlarged side view of the main parts of the operating unit when the selector switch shown in FIG. 5 is operated. FIG. 11 is an enlarged side view of the main parts of the operating unit when the cutter-moving operating member shown in FIG. 4 is operated. FIG. 12 is a schematic side view showing the first jaw and the second jaw in a closed state and the cutter advanced.

[0041] Hereinafter, the term "distal end" refers to the direction of each component that approaches biological tissue when the biological tissue is harvested. The term "base end" refers to the direction opposite to the distal end of each component. For example, in the medical device 10 shown in FIG. 1 , the first jaw 250 a and the second jaw 250 b are located more distally than the shaft member 230, and the operating unit 100 is located more proximal than the shaft member 230.

[0042] Furthermore, the "axial direction" is the direction connecting the distal end and the proximal end, and is the direction along the central axis C of the shaft member 230. The "distal end (or distal direction)" is the direction (or direction) toward the biological tissue when the biological tissue is sampled, in the axial direction. The "proximal end (or proximal direction)" is the direction (or direction) opposite to the distal end, in the axial direction, and is the direction (or direction) away from the biological tissue when the biological tissue is sampled. As can be seen from FIG. 1 , the direction (axial direction) in which the central axis C of the shaft member 230 extends is parallel to the direction in which the axis of the casing 20 extends.

[0043] Fig. 1 is a schematic overall side view of a medical device 10 according to this embodiment. Fig. 2 is an exploded perspective view of the medical device 10. The medical device 10 includes an operating section 100, a shaft member 230, a power transmission member 300, a first jaw 250a, and a second jaw 250b.

[0044] The operating unit 100 has a casing 20. As shown in FIG. 1, the casing 20 has a generally oval shape when viewed in a width direction perpendicular to the axial direction and thickness direction. The casing 20 has a first side surface 22a and a second side surface 22b located on opposite sides of the axis of the casing 20. Here, the width direction is a horizontal direction perpendicular to the axial direction. When a user views the operating unit 100 from the base end to the tip end, the user's right hand side is defined as the right, and the user's left hand side is defined as the left. The thickness direction is a direction connecting the first side surface 22a and the second side surface 22b. The "upward direction" is one direction in the thickness direction, and is the direction from the first side surface 22a to the second side surface 22b. The "downward direction" is one direction in the thickness direction, opposite to the upward direction, and is the direction from the second side surface 22b to the first side surface 22a.

[0045] The base end of the casing 20 has a base end dome portion 24, and the tip end of the casing 20 has a tip end dome portion 26. As shown in Figure 2, the base end dome portion 24 has an insertion hole 28, and the tip end dome portion 26 has a first fixing hole 30. The insertion hole 28 and the first fixing hole 30 extend along the axial direction.

[0046] The casing 20 has a first half 32a and a second half 32b. The first half 32a and the second half 32b are shaped as if the casing 20 were divided in half along the thickness direction at the center in the width direction. Therefore, as shown in FIG. 3 , when the second half 32b is removed from the first half 32a, the base end dome portion 24, the insertion hole 28, the tip end dome portion 26, and the first fixing hole 30 are divided in half. However, in the following, for simplicity and ease of understanding, the names of the components of the first half 32a and the second half 32b will be the same as those of the casing 20. That is, the first half 32a and the second half 32b each have the base end dome portion 24, the insertion hole 28, the tip end dome portion 26, and the first fixing hole 30.

[0047] FIG. 3 is a schematic perspective view of the operating unit 100, with the second half 32b not shown. As shown in FIGS. 2 and 3 , the first half 32a and the second half 32b each have an outer plate 34 and an inner plate 36 in addition to the base dome portion 24 and the tip dome portion 26. Specifically, the base dome portion 24 and the tip dome portion 26 are connected to each other via the outer plate 34. The outer plate 34 extends along the axial direction. The base dome portion 24 and the tip dome portion 26 protrude inward of the casing 20 in the width direction from the base end and tip end of the outer plate 34, respectively, in the axial direction. Therefore, the base dome portion 24 and the tip dome portion 26 are bent at approximately 90° with respect to the outer plate 34.

[0048] An inner plate portion 36 is connected to the end of the tip dome portion 26 facing inward in the width direction of the casing 20. The inner plate portion 36 extends from the tip end toward the base end so as to be aligned parallel to the outer plate portion 34. The outer plate portion 34 and the inner plate portion 36 are slightly spaced apart in the width direction. This space forms a gap 38 between the outer plate portion 34 and the inner plate portion 36. Here, the axial length of the inner plate portion 36 is shorter than the axial length of the outer plate portion 34. Therefore, an internal space 40 is formed in the first half 32a, surrounded by the base end face of the inner plate portion 36, the base end inner surface of the outer plate portion 34, and the inner surface of the base dome portion 24. The internal space 40 is in communication with the gap 38.

[0049] A first slit 42 and a second slit 44 are formed at the base end of the outer plate portion 34. The first slit 42 and the second slit 44 extend axially toward the tip end. The first slit 42 and the second slit 44 communicate only with the internal space 40 and do not communicate with the gap 38.

[0050] The inner plate portion 36 has a first connection hole 46 and a second connection hole 48 near the base end, and a support hole 50 and an engagement hole 52 near the distal dome portion 26. The first connection hole 46 and the second connection hole 48 are formed in positions that are line-symmetrical with respect to the center of the thickness of the casing 20. The support hole 50 and the engagement hole 52 are also line-symmetrical with respect to the center of the thickness of the casing 20. However, while the support hole 50 is a circular hole formed near the first side surface 22a, the engagement hole 52 is an elongated hole formed near the second side surface 22b. The first connection hole 46, the second connection hole 48, the support hole 50, and the engagement hole 52 penetrate the inner plate portion 36 in the width direction. The outer plate portion 34 is cut out at locations corresponding to the first connection hole 46, the second connection hole 48, the support hole 50, and the engagement hole 52 (see FIG. 2).

[0051] As described above, the inner surface of the distal dome portion 26 has the first fixing hole 30 extending along the axial direction. The inner surface of the inner plate portion 36 has the first guide hole 54, the second guide hole 56, and the second fixing hole 58 extending along the axial direction. The first guide hole 54, the second guide hole 56, the second fixing hole 58, and the first fixing hole 30 are aligned in this order axially from the base end to the tip end. The first guide hole 54 and the first fixing hole 30 are connected via the second guide hole 56 and the second fixing hole 58. When the first half 32a is viewed axially, the first guide hole 54, the second guide hole 56, the second fixing hole 58, and the first fixing hole 30 have a generally semicircular shape that opens inward in the width direction. The inner diameter of the first guide hole 54 is larger than the inner diameter of the second guide hole 56. Due to this difference in inner diameter, a step 80 is formed at the boundary between the first guide hole 54 and the second guide hole 56. Furthermore, the inner diameter of the first fixing hole 30 is smaller than the inner diameter of the second fixing hole 58 .

[0052] The inner surface of the inner plate portion 36 is cut out in a stepped shape below and above the first guide hole 54. As a result, a first slide hole 60 is formed below the first guide hole 54, and a second slide hole 62 is formed above the first guide hole 54. Furthermore, a third slide hole 64 is connected to the tip of the second slide hole 62. The first slide hole 60, the second slide hole 62, and the third slide hole 64 extend along the axial direction. The depth of the third slide hole 64 in the width direction is greater than the depths of the first slide hole 60 and the second slide hole 62 in the width direction.

[0053] A switch box 70 is positioned and fixed in the inner plate portion 36 on the proximal side of the engagement hole 52. The switch box 70 has a button 72 on its top surface. A first accommodating hole 74 is formed in the inner plate portion 36 further proximal side than the switch box 70. A first return spring 76 is accommodated in the first accommodating hole 74.

[0054] The second half 32b has a shape that is symmetrical to the shape of the first half 32a with the axis of the casing 20 as the center of symmetry. Therefore, with regard to the components of the second half 32b, the same components as those of the first half 32a are given the same names and reference numerals, and detailed descriptions thereof will be omitted.

[0055] The power transmission member 300 has a shaft-side slider 302 and a driven shaft 320. The driven shaft 320 will be described later.

[0056] The shaft-side slider 302 has a block portion 304 having a substantially rectangular parallelepiped shape and a sleeve portion 306 having a substantially cylindrical shape. The block portion 304 faces the base end, and the sleeve portion 306 faces the tip end. The entire block portion 304 and the entire sleeve portion 306 are housed within the casing 20. The block portion 304 is disposed in the internal space 40. The block portion 304 has a third connection hole 308 and a fourth connection hole 310 extending along the width direction. The third connection hole 308 overlaps with the first slit 42 in the width direction. The fourth connection hole 310 overlaps with the second slit 44 in the width direction. The sleeve portion 306 extending along the axial direction is slidably inserted into the first guide hole 54. A first opening 312 facing the first side surface 22a of the casing 20 and a second opening 314 facing the second side surface 22b of the casing 20 are formed on the side surface of the sleeve portion 306. The first opening 312 and the second opening 314 extend along the axial direction.

[0057] The operating unit 100 has a first operating lever 102a and a second operating lever 102b. The first operating lever 102a has a ring-shaped first finger hook 104a at its tip. A first finger hole 106a is formed in the first finger hook 104a. The first operating lever 102a further has a first tab 108a provided at its tip end near the first finger hook 104a and a pair of second tabs 110a provided at its base end away from the first finger hook 104a. The first tab 108a and the pair of second tabs 110a face the first side surface 22a of the casing 20. A fifth connection hole 112a is formed in the first tab 108a. A sixth connection hole 114a is formed in each of the pair of second tabs 110a.

[0058] The second operating lever 102b has a ring-shaped second finger hook 104b at its tip. A second finger hole 106b is formed in the second finger hook 104b. The first operating lever 102a and the second operating lever 102b face each other via the casing 20. Specifically, the first operating lever 102a and the second operating lever 102b are in a rotationally symmetrical positional relationship with the central axis C of the shaft member 230 as the center of symmetry.

[0059] The second operating lever 102b further has a third tab portion 108b provided at the tip end near the second finger hook 104b and a pair of fourth tab portions 110b provided at the base end away from the second finger hook 104b. The third tab portion 108b and the pair of fourth tab portions 110b face the casing 20. A seventh connection hole 112b is formed in the third tab portion 108b. An eighth connection hole 114b is formed in each of the pair of fourth tab portions 110b.

[0060] The operating unit 100 has a first toggle mechanism 120a and a second toggle mechanism 120b. The first toggle mechanism 120a is connected to the casing 20, the first operating lever 102a, and a shaft-side slider 302 that constitutes the power transmission member 300. Specifically, the first toggle mechanism 120a has a pair of left and right first links 122a and a pair of left and right second links 122b. The left first link 122a and the left second link 122b are rotatably connected to each other. The right first link 122a and the right second link 122b are rotatably connected to each other. Each of the pair of first links 122a has a first end 124a and a second end 124b. A pin-shaped first engaging protrusion 126a is provided at the first end 124a, and a pin-shaped second engaging protrusion 126b is provided at the second end 124b. Each of the pair of second links 122b has a third end 124c and a fourth end 124d, and a first connecting hole 128a is formed in the third end 124c. The first connecting hole 128a overlaps with the fifth connecting hole 112a in the width direction. A second connecting hole 128b is formed in the fourth end 124d. The fourth end 124d of the second link 122b is interposed between the second tab portion 110a of the first operating lever 102a and the block portion 304 of the shaft-side slider 302 in the width direction. Therefore, the sixth connecting hole 114a of the second tab portion 110a, the second connecting hole 128b of the fourth end 124d, and the third connecting hole 308 of the block portion 304 overlap in the width direction.

[0061] The first engaging protrusion 126a at the first end 124a of the first link 122a is rotatably engaged with the first connecting hole 46 formed in the casing 20. The second engaging protrusion 126b at the second end 124b of the first link 122a is rotatably engaged with the first connecting hole 128a at the third end 124c of the second link 122b and the fifth connecting hole 112a of the first tab portion 108a of the first operating lever 102a. A pin-shaped first connecting member (e.g., a bolt) (not shown) is passed through the first slit 42 of the first half 32a, the third connecting hole 308, the second connecting hole 128b, the sixth connecting hole 114a, and the first slit 42 of the second half 32b. A retaining member (e.g., a nut) is attached to the first connecting member. However, the fourth end 124d and the second tab portion 110a are rotatable relative to the block portion 304.

[0062] The second toggle mechanism 120b is connected to the casing 20, the second operating lever 102b, and the shaft-side slider 302. Specifically, the second toggle mechanism 120b has a pair of left and right third links 122c and a pair of left and right fourth links 122d. The left third link 122c and the left fourth link 122d are rotatably connected to each other. The right third link 122c and the right fourth link 122d are rotatably connected to each other. Each of the pair of third links 122c has a fifth end 124e and a sixth end 124f, with a pin-shaped third engagement protrusion 126c provided at the fifth end 124e and a pin-shaped fourth engagement protrusion 126d provided at the sixth end 124f. Each of the pair of fourth links 122d has a seventh end 124g and an eighth end 124h, and a third connection hole 128c is formed in the seventh end 124g. The third connection hole 128c overlaps with the seventh connection hole 112b in the width direction. A fourth connection hole 128d is formed in the eighth end 124h. The eighth end 124h of the fourth link 122d is interposed between the fourth tab portion 110b of the second operating lever 102b and the block portion 304 of the shaft-side slider 302 in the width direction. Therefore, the eighth connection hole 114b of the fourth tab portion 110b, the fourth connection hole 128d of the eighth end 124h, and the fourth connection hole 310 of the block portion 304 overlap in the width direction.

[0063] The third engaging protrusion 126c at the fifth end 124e of the third link 122c is rotatably engaged with the second connecting hole 48 formed in the casing 20. The fourth engaging protrusion 126d at the sixth end 124f of the third link 122c is rotatably engaged with the third connecting hole 128c at the seventh end 124g of the fourth link 122d and the seventh connecting hole 112b of the third tab portion 108b of the second operating lever 102b. A pin-shaped second connecting member (e.g., a bolt) (not shown) is passed through the second slit 44 of the first half 32a, the fourth connecting hole 310, the fourth connecting hole 128d, the eighth connecting hole 114b, and the second slit 44 of the second half 32b. A retaining member (e.g., a nut) is attached to the second connecting member. However, the eighth end 124 h and the fourth tab portion 110 b are rotatable relative to the block portion 304 .

[0064] The base end of the driven shaft 320 is inserted into the tip of the sleeve portion 306 of the shaft-side slider 302. Therefore, when the shaft-side slider 302 moves axially toward the tip or base end, the driven shaft 320 moves integrally with the shaft-side slider 302.

[0065] In the illustrated example, the driven shaft 320 is housed in the hollow interior of the shaft member 230. As the user operates the first operating lever 102a and the second operating lever 102b, power is transmitted to the driven shaft 320 via the shaft-side slider 302. As a result, the driven shaft 320 moves within the shaft member 230. In this manner, in this embodiment, the driven shaft 320 is housed within the shaft member 230 so as to be able to move.

[0066] A cylindrical spacer 130 is attached to the base end of the shaft member 230. The outer diameter of the cylindrical spacer 130 is slightly larger than the outer diameter of the shaft member 230. The cylindrical spacer 130 is fitted into the second fixing hole 58, and the shaft member 230 is fitted into the first fixing hole 30. Because the outer diameter of the cylindrical spacer 130 is larger than the inner diameters of the first fixing hole 30 and the second guide hole 56, the cylindrical spacer 130 is prevented from falling out of the second fixing hole 58 and the second guide hole 56 via the first fixing hole 30. Therefore, the shaft member 230 is also prevented from coming out of the first fixing hole 30. As can be seen from this, the cylindrical spacer 130 prevents the shaft member 230 from coming out of the first fixing hole 30.

[0067] The medical device 10 includes a cutter 150 (see FIG. 1). As shown in FIGS. 2 and 3, the operating section 100 has a cutter moving mechanism 152 for moving the cutter 150 along the axial direction of the shaft member 230. The cutter moving mechanism 152 includes a cutter moving operating member 154 shown in FIGS. 2 to 4.

[0068] In the illustrated example, the cutter movement operating member 154 is a lever 155 provided on the first side surface 22a of the casing 20. However, the cutter movement operating member 154 is not limited to the lever 155. For example, the cutter movement operating member 154 may be a slide switch. Alternatively, the cutter movement operating member 154 may be disposed on the second side surface 22b of the casing 20.

[0069] The lever 155 has a first triangular piece 156a and a second triangular piece 156b that form a substantially triangular shape when viewed in the width direction. Each of the first triangular piece 156a and the second triangular piece 156b has a support end 158, a free end 160, and a restrained end 162. A support hole 153 that overlaps with the support hole 50 of the casing 20 is formed in the support end 158. The support end 158 is rotatably connected to the support holes 50 and 153 via support members (e.g., bolts and nuts) (not shown). The free end 160 is exposed from the first side surface 22a of the casing 20. A curved wall portion 164 that curves and extends in the width direction is provided between the support end 158 and the free end 160. The curved wall portion 164 of the first triangular piece 156a and the curved wall portion 164 of the second triangular piece 156b are connected to form a semi-cylindrical push portion 166.

[0070] A pair of arc-shaped slits 168 are formed near the restraint end 162. The restraint end 162 is passed through the gap 38 and exposed to the second side surface 22b of the casing 20, but is covered by the changeover switch 200 provided on the second side surface 22b. Therefore, it is not visible from outside the casing 20.

[0071] The cutter movement mechanism 152 further includes a cutter-side slider 170 and a wire 180. The cutter-side slider 170 has a first columnar portion 172 extending axially and a second columnar portion 174 extending in the thickness direction. A pair of ejector pins 176 are provided at the tip of the first columnar portion 172. The pair of ejector pins 176 extend widthwise, are passed through a pair of arc-shaped slits 168, and are inserted into the third slide hole 64 of the first half 32a and the third slide hole 64 of the second half 32b, respectively. In other words, the restraining end 162 of the lever 155 (cutter movement operating member 154) restrains the pair of ejector pins 176 that are passed through the pair of arc-shaped slits 168, respectively.

[0072] The second pillar portion 174 is inserted into the sleeve portion 306 of the shaft-side slider 302. The lower end of the second pillar portion 174 is exposed from the first opening 312 and is inserted into the first slide hole 60. The upper end of the second pillar portion 174 is exposed from the second opening 314 and is inserted into the second slide hole 62 together with the first pillar portion 172. The second pillar portion 174 is not constrained by the sleeve portion 306. Based on this non-constraint, movement of either the shaft-side slider 302 or the cutter-side slider 170 within the casing 20 is prevented from causing the other of the shaft-side slider 302 or the cutter-side slider 170 to move.

[0073] The second columnar portion 174 holds the base end of the wire 180. The tip of the wire 180 is passed through the inside of the sleeve portion 306 and the driven shaft 320 and is connected to the base end of the cutter 150. Therefore, when the cutter-side slider 170 moves within the casing 20, the wire 180 and the cutter 150 move integrally in the same direction as the cutter-side slider 170.

[0074] A second return spring (not shown) is housed inside the casing 20. This second return spring biases the cutter side slider 170 toward the base end.

[0075] As shown in Fig. 6, the first jaw 250a has a first electrode 270a, and the second jaw 250b has a second electrode 270b. As shown in Fig. 5, the operation unit 100 has a changeover switch 200 that switches between energizing and de-energizing the first electrode 270a and the second electrode 270b. The changeover switch 200 is provided on the second side surface 22b of the casing 20. That is, in the illustrated medical device 10, the lever 155 (cutter movement operating member 154) and the changeover switch 200 are positioned symmetrically with respect to the axis of the casing 20. When the lever 155 (cutter movement operating member 154) is located on the second side surface 22b, the changeover switch 200 may be located on the first side surface 22a. The changeover switch 200 may be a lever.

[0076] In the illustrated example, the changeover switch 200 is a slide switch that can move along the axial direction. The changeover switch 200 has a nose portion 202, a roof portion 204, and legs 206. The nose portion 202 protrudes from the tip of the roof portion 204 and extends along the axial direction. The tip of the nose portion 202 has a pair of cover portions 208 that protrude downward and cover a portion of the outer surface of the casing 20 in the width direction. Each of the pair of cover portions 208 has an engagement protrusion 210 on its inner surface facing the casing 20. The engagement protrusion 210 slidably engages with the engagement hole 52, thereby preventing the changeover switch 200 from slipping out of the casing 20. The nose portion 202 further has an inclined surface 212 formed on its inner surface facing the casing 20. The inclined surface 212 is a surface that slopes upward from the tip to the base end. When the nose portion 202 is at its most distal position, the inclined surface 212 is spaced apart from the button 72 of the switch box 70 .

[0077] The legs 206 extend downward from the ceiling surface inside the roof portion 204. The lower ends of the legs 206 are inserted into the first accommodating holes 74. The first return spring 76 housed in the first accommodating holes 74 urges the selector switch 200 toward the tip via the legs 206. The interior of the roof portion 204 is hollow enough to accommodate the restraining end 162 of the cutter movement operating member 154.

[0078] As shown in FIGS. 2 and 3 , the base-end dome portion 24 further has a second housing hole 82 that communicates with the internal space 40 and the insertion hole 28. As shown in FIG. 2 , the operating unit 100 has a stopper 86 housed in the second housing hole 82. In the illustrated example, the stopper 86 also serves as a coil spring 88. The coil spring 88 biases the power transmission member 300 (the shaft-side slider 302 or the driven shaft 320) toward the tip. Alternatively, the stopper 86 may be a collar member. In this case, it is preferable to house the coil spring 88 separately from the stopper 86 within the casing 20. The coil spring 88 has a through-hole 90 extending in the axial direction.

[0079] As shown in Figure 6, the shaft member 230 has a pair of first extending portions 232. The pair of first extending portions 232 extend from the tip of the shaft member 230 along the axial direction of the shaft member 230. A pair of first notched grooves 234 is formed between the pair of first extending portions 232. The pair of first notched grooves 234 are arranged at positions 180° apart from each other in the circumferential direction. The pair of first notched grooves 234 extend along the axial direction of the shaft member 230.

[0080] A pair of support holes 236 are formed in each of the pair of first extending portions 232. The support holes 236 extend along the width direction of the casing 20 and penetrate the first extending portions 232. The centers of the pair of support holes 236 are offset by 90° in the circumferential direction of the shaft member 230 from the centers of the pair of first notched grooves 234. Both axial ends of the rotating shaft 220, which will be described later, are fitted into the pair of support holes 236, respectively. Based on this fitting, the rotating shaft 220 is positioned and fixed relative to the shaft member 230.

[0081] As shown in FIG. 7 , in which the shaft member 230 is not shown, the driven shaft 320 has a pair of second extending portions 322. The pair of second extending portions 322 extend from the tip of the driven shaft 320 along the axial direction of the driven shaft 320. A pair of second notched grooves 324 is formed between the pair of second extending portions 322. The pair of second notched grooves 324 are arranged at positions 180° apart from each other in the circumferential direction. The pair of second notched grooves 324 extend along the axial direction of the driven shaft 320. The pair of second extending portions 322 are covered by the pair of first extending portions 232. The pair of second notched grooves 324 overlap with the pair of first notched grooves 234.

[0082] A pair of guide grooves 326 and a pair of pin mounting holes 328 are formed in the pair of second extending portions 322, respectively. The pair of guide grooves 326 extend along the axial direction of the driven shaft 320 and penetrate from the outer surface to the inner surface of the pair of second extending portions 322. The pair of pin mounting holes 328 are located closer to the base end than the pair of guide grooves 326. The pair of pin mounting holes 328 are circular through holes that penetrate from the outer surface to the inner surface of the pair of second extending portions 322. The centers of the pair of guide grooves 326 and the pair of pin mounting holes 328 are shifted by 90° in the circumferential direction of the driven shaft 320 from the center of the pair of second cutout grooves 324.

[0083] The cylindrical rotating shaft 220 is inserted into each of the pair of guide grooves 326. The rotating shaft 220 moves within the guide grooves 326 relative to the driven shaft 320 in accordance with the axial displacement of the first jaw 250a and the second jaw 250b. Note that, as described above, the ends of the rotating shaft 220 are fitted into the pair of support holes 236 formed in the pair of first extending portions 232 of the shaft member 230.

[0084] Ends of the opening / closing pin 222 are inserted into the pair of pin mounting holes 328. The opening / closing pin 222 is a pin fixed to the tip of the driven shaft 320. When the first jaw 250a and the second jaw 250b are displaced along the axial direction, the opening / closing pin 222 is displaced relative to the first jaw 250a and the second jaw 250b.

[0085] 6 to 8, the first jaw 250a integrally includes a first support portion 252a and a first base end portion 254a that is continuous with the base end side of the first support portion 252a. The first support portion 252a has a first notch 256a.

[0086] The first jaw 250a supports a first main body 258a made of a plate-shaped insulator and a first electrode 270a. The first main body 258a and the first electrode 270a are supported by the first support 252a in a stacked state. The first main body 258a is interposed between the first support 252a and the first electrode 270a, and electrically insulates the first support 252a from the first electrode 270a.

[0087] The first body portion 258a has a spacer 260 that protrudes toward the second support portion 252b. A portion of the spacer 260 is exposed from a first electrode-side slit 262a formed in the first electrode 270a and protrudes toward the second support portion 252b. A first cutter groove 264a is formed in the spacer 260. The first cutter groove 264a extends in the axial direction of the first jaw 250a and guides the axial movement of the cutter 150. The spacer 260 is interposed between the cutter 150 inserted in the first cutter groove 264a and the first electrode 270a, electrically insulating the cutter 150 from the first electrode 270a.

[0088] 6 and 7 , a first power line 272a is electrically connected to the first electrode 270a. Specifically, the tip of the first power line 272a is passed through a first notch 256a formed in the first support portion 252a and then inserted into a first pierced hole 274a formed in the first body portion 258a. A portion of the surface of the first electrode 270a facing the first body portion 258a is exposed in the first pierced hole 274a. The first power line 272a is joined to the portion of the first electrode 270a exposed in the first pierced hole 274a.

[0089] The portion of the tip of the first power line 272a that is exposed from the first notch 256a is disposed along the first base end 254a. In the illustrated example, a recessed groove 276 is formed in the first base end 254a, and the tip of the first power line 272a is inserted into the recessed groove 276. The base end side of the first power line 272a is passed through, for example, the hollow interior of the driven shaft 320 and exposed from the hollow interior of the driven shaft 320 inside the casing 20. The base end side of the first power line 272a is further passed through the through-hole 90 of the coil spring 88 (stopper 86) and the insertion hole 28 of the base-end dome portion 24 of the casing 20, exposed outside the casing 20, and connected to a predetermined power supply device.

[0090] A first bearing hole 278a and a first slide groove 280a are formed in the first base end portion 254a. The rotary shaft 220 is rotatably passed through the first bearing hole 278a.

[0091] The position and shape of the second jaw 250b are rotationally symmetric to the position and shape of the first jaw 250a, with the center of rotation being the central axis C of the shaft member 230. Therefore, for the components of the second jaw 250b that correspond to the components of the first jaw 250a, the names will be changed from "first" to "second" and the reference numerals will be changed from "a" to "b", and detailed descriptions will be omitted.

[0092] A second cutter groove 264b and a second electrode side slit 262b are formed in the second main body portion 258b and the second electrode 270b, respectively. The second electrode side slit 262b overlaps the first cutter groove 264a. The second electrode side slit 262b is wider than the first cutter groove 264a. Therefore, when the cutter 150 moves into the first cutter groove 264a, the side surface of the cutter 150 is prevented from contacting the inner surface of the second electrode side slit 262b. In other words, the side surface of the cutter 150 and the side surface of the second electrode side slit 262b are not in contact with each other. This non-contact provides electrical insulation between the cutter 150 and the second electrode 270b.

[0093] 6 and 7 , the tip of the second power line 272b is passed through a second notch 256b formed in the second support portion 252b, and then inserted into a second pierced hole 274b formed in the second main body portion 258b to be electrically connected to the second electrode 270b. The base end side of the second power line 272b is passed through, for example, the hollow interior of the driven shaft 320 and exposed from the hollow interior of the driven shaft 320 inside the casing 20. The base end side of the second power line 272b is further passed through a through-hole 90 of the coil spring 88 (stopper 86) and the insertion hole 28 of the base-end dome portion 24 of the casing 20, exposed outside the casing 20, and connected to a predetermined power supply device.

[0094] 7 , when the first base end 254a of the first jaw 250a and the second base end 254b of the second jaw 250b are inserted into the second notched groove 324 of the driven shaft 320 and sandwiched between the pair of second extending portions 322, the first bearing hole 278a and the second bearing hole 278b overlap with the pair of guide grooves 326. The rotating shaft 220 is passed through one of the pair of support holes 236, one of the pair of guide grooves 326, the first bearing hole 278a, an elongated hole 151 (described later) formed in the cutter 150, the second bearing hole 278b, the other of the pair of guide grooves 326, and the other of the pair of support holes 236. In this way, the first base end 254a of the first jaw 250a and the second base end 254b of the second jaw 250b are connected via the rotating shaft 220.

[0095] When the first base end 254a of the first jaw 250a and the second base end 254b of the second jaw 250b are sandwiched between the pair of second extension portions 322 of the driven shaft 320, the pair of pin mounting holes 328 overlap with predetermined positions of the first sliding groove 280a and the second sliding groove 280b. Therefore, the opening / closing pin 222 is passed through one of the pair of pin mounting holes 328, the first sliding groove 280a, the elongated hole 151, the second sliding groove 280b, and the other of the pair of pin mounting holes 328. As will be described later, the first jaw 250a and the second jaw 250b open and close as the opening / closing pin 222 moves relative to the first sliding groove 280a and the second sliding groove 280b.

[0096] The cutter 150 is disposed between the first base end 254a and the second base end 254b. The cutter 150 extends along the axial direction of the shaft member 230 and the driven shaft 320. In an initial state, the cutter 150 is located on the base end side. Here, the operating unit 100 is provided with the cutter movement operating member 154 as described above. When the user operates the cutter movement operating member 154, the cutter 150 advances toward the tip in the axial direction or retreats toward the base end in the axial direction.

[0097] 6 to 8, the cutter 150 has an elongated hole 151 that penetrates along the thickness direction of the cutter 150. The rotary shaft 220 and the opening / closing pin 222 are passed through the elongated hole 151.

[0098] The medical device 10 according to this embodiment is basically configured as described above. Next, we will explain blood vessel harvesting using the medical device 10. Note that the user in the following description is, for example, a medical professional, typically a doctor.

[0099] To harvest a blood vessel such as a branch blood vessel BV (see FIG. 12 ) from within the patient's body, the medical device 10 and the imaging device are inserted into the patient's body. The medical device 10 is brought close to the target branch blood vessel BV, and the first jaw 250a and the second jaw 250b are placed in the open state shown in FIG. 8 . Specifically, the user inserts, for example, their little finger into the first finger hole 106a (see FIGS. 1 to 3 ) of the first operating lever 102a and their thumb into the second finger hole 106b of the second operating lever 102b. The user then moves their thumb (first finger rest 104a) and little finger (second finger rest 104b) in directions away from each other. As a result, the first operating lever 102a rotates around a pin-shaped first connecting member (not shown) inserted into the third connecting hole 308, and the second operating lever 102b rotates around a pin-shaped second connecting member (not shown) inserted into the fourth connecting hole 310. The rotation directions of the first operating lever 102a and the second operating lever 102b are directions in which the first finger hook 104a and the second finger hook 104b move away from the casing 20, respectively.

[0100] The rotation of the first operating lever 102a and the second operating lever 102b as described above causes the power transmission member 300 (the shaft-side slider 302 and the driven shaft 320) to move integrally toward the base end side because the first operating lever 102a and the shaft-side slider 302 are connected via the first toggle mechanism 120a, and the second operating lever 102b and the shaft-side slider 302 are connected via the second toggle mechanism 120b.

[0101] Here, the opening / closing pin 222 (see FIGS. 7 and 8 ) is immovable with respect to the driven shaft 320. Therefore, the opening / closing pin 222 moves toward the distal end relative to the first slide groove 280a of the first jaw 250a and the second slide groove 280b of the second jaw 250b. In other words, the first jaw 250a and the second jaw 250b are displaced toward the proximal end relative to the second notched groove 324. With this relative movement, the first jaw 250a and the second jaw 250b rotate around the rotating shaft 220. That is, the first support portion 252a of the first jaw 250a and the second support portion 252b of the second jaw 250b move away from each other. Therefore, the first jaw 250a and the second jaw 250b are in the open state shown in FIG. 8 .

[0102] As described above, when the user rotates the first operating lever 102a and the second operating lever 102b in a direction that opens the first finger hook 104a and the second finger hook 104b, the first jaw 250a and the second jaw 250b move relatively toward the base end and enter an open state. At this time, the coil spring 88 is pressed by the block portion 304 of the shaft-side slider 302 and compressed. The coil spring 88 also stops the movement of the block portion 304 within the casing 20. This stops the rotation of the first operating lever 102a and the second operating lever 102b, and also stops the rotation of the first jaw 250a and the second jaw 250b.

[0103] At this point, the cutter 150 is retracted to its most rearward position on the proximal side. While observing with the imaging device, the user places the first jaw 250a and the second jaw 250b in the open state near a predetermined branch blood vessel BV.

[0104] Next, as shown in FIG. 9 , the user moves the first support portion 252a of the first jaw 250a and the second support portion 252b of the second jaw 250b toward each other, thereby changing the first jaw 250a and the second jaw 250b to a closed state. Specifically, the user moves the thumb (first finger hook 104a) and the little finger (second finger hook 104b) toward each other. This causes the first operating lever 102a to rotate around a pin-shaped first connecting member (not shown) inserted into the third connecting hole 308, and the second operating lever 102b to rotate around a pin-shaped second connecting member (not shown) inserted into the fourth connecting hole 310. The rotation directions of the first operating lever 102a and the second operating lever 102b are directions in which the first finger hook 104a and the second finger hook 104b approach the casing 20, respectively.

[0105] As the first operating lever 102a and the second operating lever 102b rotate as described above, the power transmission member 300 (the shaft-side slider 302 and the driven shaft 320) moves integrally toward the distal end. Therefore, the open-close pin 222 moves toward the proximal end relative to the first sliding groove 280a of the first jaw 250a and the second sliding groove 280b of the second jaw 250b. In other words, the first jaw 250a and the second jaw 250b are displaced toward the distal end relative to the second notched groove 324. This relative movement causes the first jaw 250a and the second jaw 250b to rotate around the rotating shaft 220. That is, the first support portion 252a of the first jaw 250a and the second support portion 252b of the second jaw 250b approach each other. Therefore, the first jaw 250a and the second jaw 250b are in the closed state shown in FIG. 12 .

[0106] As described above, when the user rotates the first operating lever 102a and the second operating lever 102b in the closing direction, the first jaw 250a and the second jaw 250b move toward the distal end relative to the shaft member 230 and enter a closed state. As a result, the branch blood vessel BV (see FIG. 12) is sandwiched between the first support portion 252a and the second support portion 252b. Note that while FIG. 12 shows a state in which the cutter 150 has moved to the distal end, at the time the branch blood vessel BV is sandwiched between the first support portion 252a and the second support portion 252b, the cutter 150 has not moved from the position shown in FIG. 8 and is located at the proximal end.

[0107] At this point, the spacer 260 exposed from the first electrode slit 262a comes into contact with the second electrode 270b. As a result of this contact, the first electrode 270a and the second electrode 270b are slightly spaced apart from each other. In addition, the first cutter groove 264a and the second cutter groove 264b face each other.

[0108] Next, while maintaining the first jaw 250a and the second jaw 250b in a closed state, the user operates the changeover switch 200 provided on the operation unit 100, for example, as shown in FIG. 10 . The changeover switch 200 is biased toward the distal end by the first return spring 76 via the leg 206. In this state, the inclined surface 212 of the changeover switch 200 is not in contact with the button 72 of the switch box 70. In this state, the user hooks the roof portion 204 of the changeover switch 200 with, for example, their index finger and pulls it toward the proximal end. As a result, the changeover switch 200 moves toward the proximal end while compressing the first return spring 76 with the leg 206. As described above, because the engagement protrusion 210 of the nose portion 202 is engaged with the engagement hole 52, the changeover switch 200 is guided by the engagement hole 52 and moves smoothly toward the proximal end.

[0109] As the selector switch 200 moves toward the proximal end, the inclined surface 212 comes into contact with the button 72. This causes a high-frequency current to be supplied to the first electrode 270a and the second electrode 270b via the first power line 272a and the second power line 272b (see FIGS. 6 and 7). As a result, the branch blood vessel BV (see FIG. 12) sandwiched between the first support portion 252a and the second support portion 252b is cauterized, thereby stopping bleeding.

[0110] The user then releases the index finger from the roof portion 204 (see FIG. 10). Accordingly, the first return spring 76, which has been compressed by the leg portion 206, expands, and biases the selector switch 200 toward the tip via the leg portion 206. This causes the selector switch 200 to move toward the tip and return to its original position (see FIG. 5). At this time, the engaging protrusion 210 of the nose portion 202 is again guided into the engaging hole 52.

[0111] Next, while maintaining the first jaw 250a and the second jaw 250b in a closed state, the user operates the cutter movement operating member 154 as shown in FIG. 11 . Specifically, the user uses their ring finger to push the push portion 166 of the cutter movement operating member 154 up toward the second side surface 22b. This causes the cutter movement operating member 154 to rotate around the bolt or the like inserted into the support hole 50 as the rotation center. The rotation direction of the cutter movement operating member 154 is the direction in which the free end 160 approaches the first side surface 22a of the casing 20.

[0112] At the restraining end 162 of the cutter movement operating member 154, a pair of ejector pins 176 of the cutter-side slider 170 are inserted into a pair of arc-shaped slits 168, respectively. Therefore, when the cutter movement operating member 154 rotates as described above, the pair of ejector pins 176 are pushed toward the tip by the inner surfaces of the pair of arc-shaped slits 168. As a result, the cutter-side slider 170 moves toward the tip while sliding within the first slide hole 60, the second slide hole 62, and the third slide hole 64. As described above, the second columnar portion 174 of the cutter-side slider 170 is not restrained by the sleeve portion 306 of the shaft-side slider 302, and therefore the shaft-side slider 302 is prevented from moving in response to movement of the cutter-side slider 170 within the casing 20.

[0113] Therefore, the cutter 150 is pushed out by the wire 180 connected to the cutter 150 and the cutter slider 170, and is inserted into the first cutter groove 264a and the second cutter groove 264b while moving from the proximal position shown in Fig. 8 to the distal position shown in Fig. 12. The cutter 150 advances along the first cutter groove 264a and the second cutter groove 264b, and cuts the branch blood vessel BV sandwiched between the first support portion 252a and the second support portion 252b. If necessary, the medical device 10 may be advanced further inside the patient's body to cut another branch blood vessel or to dissect surrounding tissue.

[0114] After the desired range of branch blood vessels has been cut, the medical device 10 and the imaging device are removed from the patient's body, completing the main steps of blood vessel harvesting.

[0115] When the user releases his / her finger from the push portion 166, the cutter side slider 170 is urged toward the base end by the second return spring inside the casing 20. As a result, the cutter side slider 170 moves toward the base end, and the cutter side slider 170 and the cutter movement operating member 154 (lever 155) return to their original positions shown in FIG.

[0116] This embodiment has the following advantages.

[0117] 1 , the medical device 10 includes an operating unit 100 operated by a user, a shaft member 230 extending distally from the operating unit 100, and a first jaw 250a and a second jaw 250b provided at the distal end of the shaft member 230 in an openable and closable manner. The operating unit 100 includes a casing 20, a first operating lever 102a, and a second operating lever 102b. The first operating lever 102a includes a first annular finger hook 104a having a first finger hole 106a formed therein. The second operating lever 102b includes a second annular finger hook 104b having a second finger hole 106b formed therein. The first finger hole 106a is a hole through which a user inserts a finger, and the second finger hole 106b is a hole through which a user inserts a finger different from the finger inserted into the first finger hole 106a. The first operating lever 102a and the second operating lever 102b are rotatable relative to the casing 20 and face each other with the casing 20 interposed therebetween.

[0118] The medical device 10 includes a power transmission member 300. The power transmission member 300 is movable along the axial direction of the shaft member 230, and rotates the first jaw 250a or the second jaw 250b as it moves along the axial direction relative to the shaft member 230. This rotation causes the first jaw 250a and the second jaw 250b to open and close.

[0119] That is, the power transmission member 300 moves in the axial direction relative to the shaft member 230 in conjunction with the rotational movement of the first operating lever 102a and the second operating lever 102b relative to the casing 20. Based on this movement, the first jaw 250a and the second jaw 250b open and close.

[0120] In this way, the user can insert their fingers into the first operating lever 102a and the second operating lever 102b, hold the casing 20 in their palm (gripping it), and then move their fingers to apply a rotational force to the first operating lever 102a and the second operating lever 102b, thereby opening and closing the first jaw 250a and the second jaw 250b. This makes it easier for the user to apply force to their hand and move their fingers, improving the operability of the medical device 10.

[0121] 3 , 7 , 9 , and 12 , in the above-described embodiment, as the first operating lever 102a rotates so that the first finger hook 104a approaches the casing 20 and the second operating lever 102b rotates so that the second finger hook 104b approaches the casing 20, the power transmission member 300 moves toward the tip along the axial direction of the shaft member 230. Furthermore, the first jaw 250a and the second jaw 250b are in a closed state. Meanwhile, as the first operating lever 102a rotates so that the first finger hook 104a moves away from the casing 20 and the second operating lever 102b rotates so that the second finger hook 104b moves away from the casing 20, the power transmission member 300 moves toward the base end along the axial direction of the shaft member 230. Furthermore, the first jaw 250a and the second jaw 250b are in an open state.

[0122] As described above, in the above-described aspect, when both the first operating lever 102a and the second operating lever 102b are in a closed state approaching the casing 20, the first jaw 250a and the second jaw 250b are in a closed state. Also, when both the first operating lever 102a and the second operating lever 102b are in an open state away from the casing 20, the first jaw 250a and the second jaw 250b are in an open state. That is, the open / closed states of the first operating lever 102a and the second operating lever 102b match the open / closed states of the first jaw 250a and the second jaw 250b. Therefore, the user can easily recognize that the first jaw 250a and the second jaw 250b have changed from an open state to a closed state, for example, by operating the first operating lever 102a and the second operating lever 102b from an open state to a closed state.

[0123] 9 , the rotation center of the first operating lever 102a (the first connecting member, not shown, inserted into the third connecting hole 308) is provided at the base end of the casing 20, and the rotation center of the second operating lever 102b (the second connecting member, not shown, inserted into the fourth connecting hole 310) is provided at the base end of the casing 20. The first operating lever 102a rotates such that the first finger hook 104a moves closer to or away from the casing 20 on the tip side of the rotation center. Similarly, the second operating lever 102b rotates such that the second finger hook 104b moves closer to or away from the casing 20 on the tip side of the rotation center.

[0124] In this case, the user can insert his or her fingers into the first finger rest 104a and the second finger rest 104b, and then move his or her fingers to easily rotate the first operating lever 102a and the second operating lever 102b.

[0125] 2 and 3 , the operating unit 100 includes a first toggle mechanism 120a connected to the casing 20, the first operating lever 102a, and the power transmission member 300, and a second toggle mechanism 120b connected to the casing 20, the second operating lever 102b, and the power transmission member 300. The first toggle mechanism 120a has a first link 122a and a second link 122b that are rotatably connected to each other. The first link 122a has a first end 124a rotatably connected to the casing 20 and a second end 124b rotatably connected to the second link 122b. The second link 122b has a third end 124c rotatably connected to the second end 124b and a fourth end 124d rotatably connected to the power transmission member 300. The first operating lever 102a is connected to the connecting point between the second end 124b and the third end 124c.

[0126] The second toggle mechanism 120b has a third link 122c and a fourth link 122d that are rotatably connected to each other. The third link 122c has a fifth end 124e that is rotatably connected to the casing 20 and a sixth end 124f that is rotatably connected to the fourth link 122d. The fourth link 122d has a seventh end 124g that is rotatably connected to the sixth end 124f and an eighth end 124h that is rotatably connected to the power transmission member 300. The second operating lever 102b is connected to the connection between the sixth end 124f and the seventh end 124g.

[0127] In other words, the power transmission member 300 constitutes the first toggle mechanism 120a together with the first link 122a and the second link 122b, and constitutes the second toggle mechanism 120b together with the third link 122c and the fourth link 122d. Therefore, the user can easily move the power transmission member 300 by rotating the first operating lever 102a and the second operating lever 102b with a small force.

[0128] 1, 6, 7, 8, and 12, the medical device 10 includes a cutter 150 that excises biological tissue such as a branch blood vessel BV. The operating unit 100 has a cutter movement operating member 154 in the casing 20 for moving the cutter 150 along the axial direction of the shaft member 230. The cutter movement operating member 154 is located closer to the distal end than the first finger rest 104a or the second finger rest 104b.

[0129] Here, the casing 20 has a first side surface 22a and a second side surface 22b located on opposite sides of the axis of the casing 20. The first operating lever 102a is disposed on the first side surface 22a. The second operating lever 102b is disposed on the second side surface 22b. The cutter movement operating member 154 is disposed on the first side surface 22a (or the second side surface 22b).

[0130] Since biological tissue such as branch blood vessels BV can be excised by the cutter 150, it is easy to collect biological tissue. Furthermore, while holding the casing 20 in the palm of the user's hand, the user can easily touch the cutter movement operating member 154 with the fingers that are not inserted in the first finger hole 106a or the second finger hole 106b. Therefore, the user can easily move the cutter 150.

[0131] In one aspect, the cutter movement operating member 154 is a lever 155 shown in Figures 4 and 11. One end of the lever 155 is connected to the casing 20 via a support member on the tip side of the first finger hook 104a or the second finger hook 104b. The lever 155 is rotatable around the support member as the center of rotation such that a free end 160, which is the other end of the lever 155, moves toward or away from the casing 20. By rotating the lever 155 so that the free end 160 of the lever 155 moves toward the casing 20, the cutter 150 moves toward the tip along the axial direction of the shaft member 230.

[0132] As described above, the user can easily touch the lever 155 with a finger that is not inserted in either the first finger hole 106a or the second finger hole 106b. Furthermore, one end of the lever 155 (support end 158) facing the tip of the casing 20 is connected to the casing 20, and the other end (free end 160) facing the base end of the casing 20 is located closer to the tip of the casing 20 than the first finger hook 104a or the second finger hook 104b. Therefore, the user can easily rotate the lever 155 by pressing the other end of the lever 155 toward the casing 20 with a finger. This allows the user to easily move the cutter 150.

[0133] 6 to 8 and 12, the first jaw 250a and the second jaw 250b have a first electrode 270a and a second electrode 270b, respectively, for cauterizing biological tissue. The operation unit 100 has a changeover switch 200 in the casing 20 that switches between energizing and de-energizing the first electrode 270a and the second electrode 270b. The changeover switch 200 is located closer to the distal end than the first finger rest 104a or the second finger rest 104b.

[0134] The casing 20 has a first side surface 22a and a second side surface 22b located on opposite sides of the axis of the casing 20. The first operating lever 102a is disposed on the first side surface 22a. The second operating lever 102b is disposed on the second side surface 22b. The changeover switch 200 is disposed on the second side surface 22b (or the first side surface 22a).

[0135] By passing current between the first electrode 270a and the second electrode 270b, it is possible to cauterize biological tissue sandwiched between the first jaw 250a and the second jaw 250b. Therefore, if the biological tissue is a blood vessel, it is possible to quickly stop bleeding when sampling the blood vessel. Furthermore, while holding the casing 20 in the palm of the user's hand, the user can easily touch the selector switch 200 with a finger that is not inserted in the first finger hole 106a or the second finger hole 106b. Therefore, the user can easily switch between energizing and de-energizing the first electrode 270a and the second electrode 270b.

[0136] As can be seen with reference to FIGS. 5 and 10, the changeover switch 200 is movable along the axial direction of the shaft member 230 toward the distal end or the proximal end.

[0137] According to this configuration, the user can easily switch between energizing and de-energizing the first electrode 270a and the second electrode 270b by moving the changeover switch 200 along the axial direction of the casing 20 toward the tip or base end with a finger that is not inserted in the first finger hole 106a and not inserted in the second finger hole 106b.

[0138] When both the cutter movement operating member 154 and the changeover switch 200 are provided in the casing 20, the changeover switch 200 is arranged on one of the first side surface 22a and the second side surface 22b, and the cutter movement operating member 154 is arranged on the other of the first side surface 22a and the second side surface 22b.

[0139] With this configuration, the user can individually touch the cutter movement operating member 154 or the changeover switch 200 with the fingers that are not inserted in the first finger hole 106a or the second finger hole 106b while holding the casing 20 in the palm of their hand. This allows the user to easily move the cutter 150 and easily switch between energizing and deenergizing the first electrode 270a and the second electrode 270b.

[0140] The casing 20 has an insertion hole 28 at its base end for passing a first power line 272a electrically connected to the first electrode 270a and a second power line 272b electrically connected to the second electrode 270b.

[0141] The base end of the casing 20 is a location that is not touched by the user's fingers or palm, which prevents the first power line 272 a and the second power line 272 b from interfering with the user's operation of the medical device 10.

[0142] The operating unit 100 has a stopper 86 inside the casing 20 , on the proximal side of the proximal end of the power transmission member 300 , which stops the movement of the power transmission member 300 toward the proximal end of the casing 20 .

[0143] The opening operation (or closing operation) of first jaw 250a and second jaw 250b is stopped when power transmission member 300 abuts against stopper 86. Therefore, for example, excessive opening of first jaw 250a and second jaw 250b is prevented, making it easy to insert first jaw 250a and second jaw 250b into the body of a living organism.

[0144] The operating portion 100 has a coil spring 88 inside the casing 20 that biases the power transmission member 300 in the distal direction.

[0145] For example, after the first operating lever 102a and the second operating lever 102b are rotated from the closed state to the open state by the user's operation, when the user removes their fingers from the first finger hole 106a and the second finger hole 106b, the coil spring 88 elastically pushes the power transmission member 300. As a result, the first operating lever 102a and the second operating lever 102b change from the open state to the closed state. Therefore, the user does not need to perform any operation to return the first operating lever 102a and the second operating lever 102b from the open state to the closed state.

[0146] 6 to 9, the first jaw 250a and the second jaw 250b have a first electrode 270a and a second electrode 270b, respectively, for cauterizing biological tissue. As shown in Fig. 2, the coil spring 88, which also serves as the stopper 86, has a through-hole 90 for passing a first power line 272a (see Figs. 6 and 7) electrically connected to the first electrode 270a and a second power line 272b electrically connected to the second electrode 270b. The casing 20 has an insertion hole 28, located closer to the proximal end of the stopper 86 than the proximal end, for passing the first power line 272a and the second power line 272b.

[0147] The first power line 272 a and the second power line 272 b can be passed through the through-hole 90 of the stopper 86 and into the insertion hole 28 formed at a more proximal end than the stopper 86. Therefore, even though the stopper 86 is provided inside the casing 20, the first power line 272 a and the second power line 272 b can be exposed from the inside of the casing 20 to the outside.

[0148] 2 and 3 , the shaft member 230 is hollow. Most of the driven shaft 320, which is a part of the power transmission member 300, is inserted inside the shaft member 230. The driven shaft 320 is capable of moving relative to the shaft member 230.

[0149] By inserting a portion of the power transmission member 300 inside the shaft member 230, the medical device 10 can be made smaller.

[0150] Modifications of the present invention will be described below.

[0151] The mechanism that converts the rotational movement of the first operating lever 102a and the second operating lever 102b into the linear movement of the power transmission member 300 may be a mechanism other than the first toggle mechanism 120a and the second toggle mechanism 120b. Examples of such a mechanism include a gear mechanism and a belt mechanism.

[0152] The rotation centers of the first operating lever 102a and the second operating lever 102b may be located closer to the tip than the first finger rest 104a and the second finger rest 104b, respectively.

[0153] The rotation direction (opening / closing direction) of the first operating lever 102a and the second operating lever 102b may be different from the opening / closing direction of the first jaw 250a and the second jaw 250b. For example, the first operating lever 102a and the second operating lever 102b may open and close along the left and right (width direction), and the first jaw 250a and the second jaw 250b may open and close along the up and down (thickness direction).

[0154] In the above embodiment, a configuration in which both the first jaw 250a and the second jaw 250b rotate has been exemplified, but a configuration in which only one of the first jaw 250a and the second jaw 250b rotates may also be used. For example, a configuration in which the first jaw 250a is fixed in position and the second jaw 250b is rotatable relative to the first jaw 250a may also be used. In this way, it is not essential that both the first jaw 250a and the second jaw 250b rotate.

[0155] 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 comprising: an operating section operated by a user; a shaft member extending from the operating section in a distal direction; and a first jaw and a second jaw provided at the distal end of the shaft member in an openable and closable manner, wherein the operating section comprises: a casing; a first operating lever rotatable relative to the casing and having a first annular finger hook portion formed with a first finger hole into which the user inserts a finger; and a second operating lever rotatable relative to the casing and having a second annular finger hook portion formed with a second finger hole into which the user inserts a finger other than the finger inserted into the first finger hole, wherein the first operating lever and the second operating lever face each other via the casing; and the medical device comprises a power transmission member movable along the axial direction of the shaft member and configured to rotate at least one of the first jaw or the second jaw so that the first jaw and the second jaw open and close as the medical device moves in the axial direction relative to the shaft member, A medical device, wherein the power transmission member moves in the axial direction relative to the shaft member in conjunction with the pivoting movement of the first operating lever and the second operating lever relative to the casing.

2. A medical device as described in claim 1, wherein, as the first operating lever rotates so that the first finger hook approaches the casing and the second operating lever rotates so that the second finger hook approaches the casing, the power transmission member moves along the axial direction of the shaft member toward the tip and the first jaw and the second jaw are in a closed state; and as the first operating lever rotates so that the first finger hook moves away from the casing and the second operating lever rotates so that the second finger hook moves away from the casing, the power transmission member moves along the axial direction of the shaft member toward the base end and the first jaw and the second jaw are in an open state.

3. A medical device according to claim 1 or 2, wherein the center of rotation of the first operating lever and the second operating lever is provided at the base end of the casing, and the first operating lever and the second operating lever rotate so that the first finger hook portion and the second finger hook portion move away from or towards the casing on the tip side of the center of rotation.

4. In the medical device according to claim 1 or 2, the operating section comprises: a first toggle mechanism connected to the casing, the first operating lever, and the power transmission member; and a second toggle mechanism connected to the casing, the second operating lever, and the power transmission member, the first toggle mechanism having a first link and a second link rotatably connected to each other, the first link having a first end rotatably connected to the casing and a second end rotatably connected to the second link, the second link having a third end rotatably connected to the second end and a fourth end rotatably connected to the power transmission member, the first operating lever being connected to a connection point between the second end and the third end, the second toggle mechanism having a third link and a fourth link rotatably connected to each other, the third link having a fifth end rotatably connected to the casing and a sixth end rotatably connected to the fourth link, the fourth link has a seventh end rotatably connected to the sixth end and an eighth end rotatably connected to the power transmission member, and the second operating lever is connected to a connection point between the sixth end and the seventh end.

5. A medical device as described in claim 1, comprising a cutter for excising biological tissue, wherein the operating section has a cutter moving operating member on the casing for moving the cutter along the axial direction of the shaft member, the cutter moving operating member being located distally of the first finger hook portion or the second finger hook portion, the casing having a first side and a second side located opposite each other with respect to the axis of the casing, the first operating lever being disposed on the first side, the second operating lever being disposed on the second side, and the cutter moving operating member being disposed on the first side or the second side.

6. A medical device as described in claim 5, wherein the cutter moving operating member is a lever, one end of the lever is connected to the casing via a support member on the tip side of the first finger hook portion or the second finger hook portion, the lever is rotatable around the support member as a rotation center so that the other end, which is a free end, of the lever moves closer to or away from the casing, and the cutter moves along the axial direction of the shaft member toward the tip when the lever rotates so that the free end of the lever approaches the casing.

7. A medical device as described in claim 1, wherein the first jaw and the second jaw respectively have a first electrode and a second electrode for cauterizing biological tissue, the operating section has a change-over switch in the casing for switching between passing current or not passing current between the first electrode and the second electrode, the change-over switch being located distally of the first finger hook portion or the second finger hook portion, the casing having a first side and a second side located opposite each other with respect to an axis of the casing, the first operating lever being disposed on the first side, the second operating lever being disposed on the second side, and the change-over switch being disposed on the first side or the second side.

8. A medical device according to claim 7, wherein the changeover switch is movable along the axial direction of the shaft member toward the distal end or proximal end.

9. A medical device according to claim 1, comprising a cutter for excising biological tissue, wherein the first jaw and the second jaw respectively have a first electrode and a second electrode for cauterizing the biological tissue, wherein the operating section comprises a change-over switch for switching between energizing and stopping energization between the first electrode and the second electrode, and a cutter moving operating member for moving the cutter along the axial direction of the casing, on the casing, wherein the change-over switch is located further distal than the first finger hook or the second finger hook, and the cutter moving operating member is located further distal than the first finger hook or the second finger hook, the casing has a first side and a second side located opposite each other with respect to the axis of the casing, the first operating lever is disposed on the first side, and the second operating lever is disposed on the second side, the change-over switch is disposed on one of the first side and the second side, and the cutter moving operating member is disposed on the other of the first side and the second side.

10. A medical device according to any one of claims 7 to 9, wherein the casing has an insertion hole at its base end for passing a first power line electrically connected to the first electrode and a second power line electrically connected to the second electrode.

11. A medical device as described in claim 1, wherein the operating portion has, inside the casing, a stopper located proximal to the proximal end of the power transmission member, for stopping the movement of the power transmission member toward the proximal end of the casing.

12. A medical device according to claim 1, wherein the operating section has a coil spring inside the casing for urging the power transmission member in the distal direction.

13. A medical device according to claim 11, wherein the first jaw and the second jaw respectively have a first electrode and a second electrode for cauterizing biological tissue, the stopper has a through hole for passing a first power line electrically connected to the first electrode and a second power line electrically connected to the second electrode, and the casing has an insertion hole for passing the first power line and the second power line on the proximal side of the proximal end of the stopper.

14. A medical device according to claim 1, wherein the shaft member is hollow, and a portion of the power transmission member is inserted inside the shaft member so as to be movable relative to the shaft member.

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