Medical device

Abstract

To provide a medical device capable of taking an intravascular object into a drive shaft while efficiently cutting off the object.SOLUTION: A medical device 10 comprises: a drive shaft 20 having a tip 25 and rotatable about an axis X; and a blade surface part 40 which is provided at the tip 25 and rotated by the rotation of the drive shaft 20 to cut off an object. The blade surface part 40 comprises a hollow body 41 having a peripheral surface 41a. The body 41 includes: an opening 42 provided in the peripheral surface 41a to make the internal hollow and the outside communicate with each other; and a blade surface 43 sharp toward the rotation direction of the opening 42.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a medical device for removing an object from a biological lumen. [Background technology]

[0002] Methods for treating stenosis caused by intravascular plaque, thrombus, etc. include expanding the blood vessel with a balloon and placing a mesh or coil stent in the blood vessel to support the blood vessel. However, these methods are difficult to use to treat stenosis that has hardened due to calcification or that occurs at a branching point of the blood vessel. One method that can be used to treat such cases is to remove the plaque, thrombus, or other stenotic material by cutting it.

[0003] For example, Patent Document 1 describes a device in which a cutting tip for cutting an object is provided at the tip of a rotating drive shaft. This device rotates the drive shaft, cutting an object with the cutting tip and taking it into the drive shaft. In addition, a side hole is provided on the side of the cutting tip, and an object can also be taken into the drive shaft through the side hole. This device has a housing at the hand side that has an ejection port that applies suction force. The object taken into the drive shaft is moved toward the base end. The object then moves into the housing through the ejection hole of the drive shaft and is ejected from the ejection port. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 141922 Summary of the Invention [Problem to be solved by the invention]

[0005] In large blood vessels, especially veins, the blood flow velocity is low, making large clots more likely to form. To capture a large object into the drive shaft, the object must be efficiently cut into small pieces.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a medical device that can efficiently cut an object inside a blood vessel while taking it into the inside of a drive shaft. [Means for solving the problem]

[0007] One aspect of the medical device (1) according to the present invention that achieves the above-mentioned object includes a shaft having a tip portion that can rotate around an axis, and a blade surface portion that is provided at the tip portion and rotates with the rotation of the shaft to cut an object, the blade surface portion having a hollow main body portion with a peripheral surface, the main body portion including an opening provided at the peripheral surface that connects the hollow interior with the outside, and a blade surface that is sharp in the direction of rotation of the opening.

[0008] Another aspect of the (10) medical device according to the present invention that achieves the above-mentioned object includes a shaft having a tip portion that can rotate around an axis, and a blade surface portion that is provided at the tip portion and rotates with the rotation of the shaft to cut an object, the blade surface portion having a main body portion with a space inside, the main body portion having an opening that opens so that the object can be taken into the space and has a pair of opening edges that are parallel or non-parallel to the axial direction of the shaft, one of the pair of opening edges being a sharp blade surface. [Effects of the Invention]

[0009] The medical devices (1) and (10) configured as described above have a sharp blade surface at the opening that connects the inside and outside of the main body that forms the blade surface portion. As a result, by rotating the shaft, the object located at the opening can be cut into small pieces with the blade surface and taken into the inside of the main body, thereby efficiently cutting and removing the object.

[0010] (2) In the medical device of (1) above, the main body may be cylindrical, which allows the opening of the medical device to be wide from the distal end to the proximal end, making it easier to take in an object.

[0011] (3) In the medical device of (1) above, the main body may be frustoconical, which allows the outer diameter of the main body at the distal end of the medical device to be reduced, making it easier to insert the distal end of the medical device into a blood vessel.

[0012] (4) In any of the medical devices (1) to (3) above, the blade surface may extend in a direction non-parallel to the axial direction of the shaft, thereby making it easier for the blade surface to cut an object because the blade surface is angled with respect to the rotational direction of the shaft.

[0013] (5) In any of the medical devices (1) to (4) above, the blade surface may be provided so as to be inclined in a circumferential direction around the shaft toward the base end of the shaft in a direction opposite to the rotation direction, thereby making it easier for the blade surface to cut an object caught at the distal end portion of the opening of the medical device.

[0014] (6) In the medical device of (5) above, the blade surface may be provided so as to extend in the circumferential direction around the shaft in one direction as viewed from the distal end of the shaft, in the other direction toward the proximal end of the shaft. This allows the medical device to cut an object from the distal end toward the proximal end as the shaft rotates, thereby enabling the object to be cut more reliably.

[0015] (7) In the medical device of (6) above, the blade surface may be spirally shaped along a circumferential direction around the shaft toward the base end of the shaft, thereby making it easier for the medical device to cut an object with the spiral-shaped blade surface.

[0016] (8) In any of the medical devices (1) to (3) above, the blade surface may extend in a direction parallel to the axial direction of the shaft. This ensures that the circumferential position of the blade surface is constant along the axial direction of the medical device, thereby preventing the blade surface from coming into contact with a blood vessel wall or the like.

[0017] (9) In any of the medical devices (1) to (8) above, the opening may have a notch that separates the leading edge of the opening from the tip of the blade surface, and the tip of the blade surface may have a sharp edge. This allows the sharp edge formed at the tip of the blade surface of the medical device to pierce an object, thereby more reliably cutting the object.

[0018] (11) In the medical device of (10) above, the blade surface may be provided so as to be inclined in a circumferential direction around the axis toward the base end of the axis in a direction opposite to the rotation direction of the shaft, thereby making it easier for the blade surface to cut an object caught at the distal end portion of the opening of the medical device.

[0019] (12) In the medical device of (10) or (11) above, the opening may have a notch that separates the leading edge of the opening from the tip of the blade surface, and the tip of the blade surface may have a sharp edge. This allows the sharp edge formed at the tip of the blade surface of the medical device to pierce an object, thereby more reliably cutting the object. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a front view showing the medical device and the drive device according to the present embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing the proximal end of a medical device. [Figure 3] FIG. 1 is a front view showing the distal end of a medical device. [Figure 4] FIG. 4 is a cross-sectional view of the AA end of FIG. [Figure 5] 4A is a BB end view of FIG. 3, and FIG. 4B is a CC end view of FIG. [Figure 6] FIG. 4 is a front view of FIG. 3 rotated 90 degrees around the axis of the shaft. [Figure 7] 1A and 1B are front views showing the operating handle, outer tube, and drive shaft, in which FIG. 1A shows the state in which the distal end of the sheath is straight, and FIG. 1B shows the state in which the distal end of the sheath is curved by operating the operating handle. [Figure 8] 10A and 10B are diagrams showing a state in which the distal end of a medical device is rotating within a blood vessel, showing the medical device in a front view and the blood vessel in a cross-sectional view. [Figure 9] FIG. 10 is a front view showing a modified example of the cylindrical cutting surface portion. [Figure 10] FIG. 10 is a front view showing a modified example of a truncated cone-shaped cutting surface portion. [Figure 11] FIG. 10 is a cross-sectional view showing a modified example of the blade surface portion in which the angle of the blade surface is changed. [Figure 12] FIG. 10 is a front view of a blade surface portion according to a modified example having blade surfaces on both sides of an opening. [Figure 13] 12. (a) is an AA end view of FIG. 12, and (b) is a BB end view of FIG. [Figure 14] FIG. 10 is a front view of a blade surface portion according to another modified example having blade surfaces on both sides of the opening. [Figure 15] 14A is an AA end view of FIG. 14, and FIG. 14B is a BB end view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the size and proportions of the components in the drawings may be exaggerated for the sake of explanation and may differ from the actual size and proportions.

[0022] The medical device 10 according to this embodiment is inserted into a blood vessel and used in treatments such as acute lower limb ischemia and deep vein thrombosis to cut and remove objects such as thrombi and plaque. In this specification, the side of the device that is inserted into the blood vessel is referred to as the "distal side," and the side that is operated by the operator is referred to as the "proximal side." Note that the objects to be removed are not necessarily limited to thrombi and plaque, and may include any object that may be present in a biological lumen.

[0023] 1 and 2, the medical device 10 is coupled to and driven by a driving device 200 that generates driving force and suction force. The medical device 10 comprises a long, rotatably driven drive shaft 20, an outer tube 30 that houses the drive shaft 20 and is covered by a sheath 31, and a distal end portion 25 having a cutting edge 40 for cutting an object. The medical device 10 further comprises an inner tube 35 disposed inside the drive shaft 20, and a proximal shaft 90 fixed to the proximal end of the drive shaft 20. The medical device 10 further comprises a housing 60 that rotatably houses the proximal end of the drive shaft 20, an operating handle 80 that allows the surgeon to operate the outer tube 30, and a rotation input portion 110 that receives rotational force from the driving device 200.

[0024] The drive shaft 20 transmits rotational force to a distal end 25 having a cutting surface 40. The drive shaft 20 is formed with an aspiration lumen 21 (inner cavity) for moving the cut object toward the proximal end. The drive shaft 20 includes a drive shaft main body 22, a drive shaft proximal end 23 fixed to the proximal end, and an auxiliary member 24. The drive shaft 20 passes through an outer tube 30. The proximal end of the drive shaft 20 is located inside the housing 60. The proximal end of the drive shaft 20 is connected to a proximal shaft 90. The drive shaft 20 has an opening 42 at its distal end 25, through which the aspiration lumen 21 opens. The opening 42 is an entrance through which debris, which is the object to be aspirated and formed by cutting, enters. The drive shaft 20 has a proximal opening 26 at its proximal end. The proximal opening 26 is an exit through which debris that has entered the interior of the drive shaft 20 through the opening 42 is expelled. The proximal end opening 26 is formed by removing a portion of the drive shaft 20 in the circumferential direction. The proximal end opening 26 is formed at the proximal end of the drive shaft 20, penetrating the inner and outer wall surfaces of the drive shaft 20. Therefore, the proximal end opening 26 opens laterally (in a direction perpendicular to the central axis X of the drive shaft 20). A distal end edge 26a of the proximal end opening 26 is formed substantially perpendicular to the central axis X. A proximal end edge 26b of the proximal end opening 26 is formed as an arc that convex toward the proximal end. By providing the proximal end opening 26 with a cutting edge that is sharp in the rotation direction, an object positioned at the proximal end opening 26 can be cut with the cutting edge and finely fragmented by the rotation of the drive shaft 20, and then discharged outside the housing 60, thereby efficiently cutting and removing the object.

[0025] The drive shaft body 22 is flexible and has the property of being able to transmit rotational power acting from the base end side to the tip end side.

[0026] The drive shaft proximal end 23 has a generally cylindrical shape and is formed with a proximal end opening 26. The distal end of the drive shaft proximal end 23 is fixed to and covers the outer circumferential surface of the drive shaft 20. The drive shaft proximal end 23 is rotatably supported by a first bearing 67 and a second bearing 68 disposed inside the housing 60. This allows the drive shaft 20 to rotate smoothly at high speed. The shape of the drive shaft 20 is not particularly limited as long as it can transmit rotational power and has an inner lumen and a proximal end opening 26.

[0027] An auxiliary member 24, whose length along the central axis X is shorter than that of the drive shaft base end 23, is fixed to and covers the outer peripheral surface of the drive shaft base end 23. The auxiliary member 24 has a generally cylindrical shape. An opening having a shape generally identical to that of the base end opening 26 is formed in the auxiliary member 24 at a position overlapping the base end opening 26. The distal end surface of the auxiliary member 24 abuts against a first bearing 67 that supports the drive shaft base end 23. The proximal end surface of the auxiliary member 24 abuts against a second bearing 68 that supports the drive shaft base end 23. Therefore, the auxiliary member 24 properly maintains the positions of the first bearing 67 and the second bearing 68 relative to the drive shaft base end 23. The auxiliary member 24 also reinforces the drive shaft base end 23 where the base end opening 26 is formed. The auxiliary member 24 is not necessarily provided.

[0028] The distal end of proximal shaft 90 enters the lumen of drive shaft proximal end 23 from the proximal end side and is fixed to drive shaft proximal end 23. A rotation input portion 110 that receives a rotational force from drive device 200 is fixed to the proximal end of proximal shaft 90. The proximal end of proximal shaft 90 protrudes from housing 60 toward the proximal end side.

[0029] The material of drive shaft body 22 is not particularly limited, but suitable materials include stainless steel, Ta, Ti, Pt, Au, W, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as ETFE, PEEK (polyether ether ketone), polyimide, etc. Also, the drive shaft body may be made of multiple materials, and a reinforcing member such as a wire may be embedded in the body.

[0030] The constituent materials of drive shaft base end portion 23, auxiliary member 24, and base end shaft 90 are not particularly limited, but suitable materials include stainless steel, Ta, Ti, Pt, Au, W, and shape memory alloys. The constituent materials of drive shaft base end portion 23, auxiliary member 24, and base end shaft 90 may also be resins such as engineering plastics, such as PEEK (polyether ether ketone).

[0031] 2, the rotation input part 110 is a substantially cylindrical member fixed to the base end of the drive shaft 20. The rotation input part 110 is a member that is coupled to the rotation drive shaft 221 of the drive device 200 and receives rotational power. The base end of the rotation input part 110 is provided with a fitting recess 111 into which the rotation drive shaft 221 fits.

[0032] As shown in Fig. 2, the inner pipe 35 is a flexible pipe body that is disposed inside the drive shaft 20. The inner pipe 35 prevents the inner circumferential surface of the drive shaft 20 from being damaged by debris flowing inside the drive shaft 20. The inner pipe 35 may be fixed to the inner circumferential surface of the drive shaft 20, but does not have to be fixed thereto. Note that the inner pipe 35 does not necessarily have to be provided.

[0033] 2, the housing 60 has a first section 61 located on the distal end side, a second section 62 located approximately in the center, a third section 63 located on the proximal end side, and a fourth section 64. The housing 60 further has a discharge port 70 to which a suction tube 231 of the drive device 200, which will be described later, can be connected. The housing 60 defines an internal space 65 by assembling these components. The internal space 65 communicates with a passage 71 of the discharge port 70 and with the suction tube 231 of the drive device 200, which is connected to the discharge port 70. A first bearing 67 and a second bearing 68 are disposed inside the housing 60, and each support the drive shaft 20 rotatably relative to the housing 60.

[0034] Fourth portion 64 carries a seal 69 disposed between third portion 63 and proximal shaft 90. Seal 69 seals interior space 65 while allowing proximal shaft 90 to rotate.

[0035] The proximal end opening 26 of the drive shaft 20 is located in the internal space 65. Therefore, the negative pressure acting on the discharge port 70 from the suction tube 231 acts on the inside of the drive shaft 20 from the proximal end opening 26.

[0036] 2, the discharge port 70 has a generally cylindrical shape, with one end located on the exterior side of the housing 60 and the other end communicating with the internal space 65 of the housing 60. The discharge port 70 has a passage 71 formed therein that passes through from one end to the other end.

[0037] As shown in FIG. 1, the drive device 200 includes a drive unit 220 that generates a rotational force and a suction unit 230 that generates a suction force.

[0038] The driving unit 220 includes a rotary drive shaft 221 and a first motor 222 that rotates the rotary drive shaft 221. The rotation speed of the first motor 222 is not particularly limited, but is, for example, 5,000 to 200,000 rpm.

[0039] The suction unit 230 includes a suction tube 231, a pump 232, a second motor 233, and a waste fluid pack 235. The suction tube 231 can be connected to the discharge port 70 of the medical device 10. The pump 232 is driven by the second motor 233 to apply negative pressure to the suction tube 231. The pump 232 also discharges the fluid sucked through the suction tube 231 into the waste fluid pack 235.

[0040] It should be noted that the configuration of the drive device 200 is not limited to the above example. For example, the mechanism that generates the rotational force and the mechanism that generates the suction force may be separate devices.

[0041] As shown in Figures 1 and 3, the cutting edge 40 provided at the distal end 25 of the drive shaft 20 is a component that cuts and reduces objects such as thrombi, plaque, and calcified lesions. "Cutting" refers to applying force to an object in contact with it to reduce the object. The shape and form of the object after cutting are not limited.

[0042] 3, the distal end portion 25 of the drive shaft 20 includes a cutting surface portion 40 and a flexible portion 50 disposed on the proximal side of the cutting surface portion 40. The most distal end portion 28 of the distal end portion 25 has a bullet-like shape with an outer diameter that decreases toward the tip.

[0043] The blade surface portion 40 includes a hollow, cylindrical main body portion 41 having a lumen 45. The lumen 45 is in communication with the suction lumen 21 of the drive shaft 20. The main body portion 41 has an outer peripheral surface 41a extending in the circumferential direction about the axis X of the drive shaft 20. An opening 42 is provided on the outer peripheral surface 41a, connecting the hollow interior of the main body portion 41 with the outside. The opening 42 is open so that an object can be taken into the lumen 45, which is a space. The opening 42 forms a pair of opening edges: a first opening edge 42a that is substantially parallel to the axis X of the drive shaft 20, and a second opening edge 42b that faces the first opening edge 42a and is non-parallel to the axis X. One of the pair of opening edges, the second opening edge 42b, forms a sharp blade surface 43. The first opening edge 42a is not blade-shaped. The first opening edge 42a and the second opening edge 42b are connected via a distal opening edge 42c on the distal side of the opening 42. The first opening edge 42a and the second opening edge 42b are connected via a proximal opening edge 42d on the proximal side of the opening 42.

[0044] The blade surface 43 extends in a direction non-parallel to the axial direction X of the drive shaft 20. The blade surface 43 extends in a circumferential direction about the axis X so that the distance from the first opening edge 42a increases toward the proximal end of the axis X. In FIG. 3, the drive shaft 20 rotates counterclockwise as viewed from the distal end. The blade surface 43 is spirally provided in a clockwise direction in the circumferential direction about the axis X toward the proximal end of the axis X, which is the opposite direction to the rotation direction of the drive shaft 20 as viewed from the distal end. The opening 42 has a notch 44 that separates the distal opening edge 42c of the opening 42 from the tip of the blade surface 43, and the tip of the blade surface 43 has a sharp end 43c. The notch 44 is a U-shaped groove that smoothly extends from the distal opening edge 44a, which is the distal opening edge 42c, to the proximal opening edge 44b. However, the shape is not limited to the above as long as the sharp end 43c is formed.

[0045] As shown in FIG. 4( a), the blade surface 43 is positioned so as to face the direction in which the opening 42 rotates as the drive shaft 20 rotates. The blade surface 43 has a sharp shape that can cut an object, with a first surface 43 a that forms the edge of the opening 42 and a second surface 43 b that forms the circumferential surface 41 a of the main body 41 intersecting at an acute angle. Therefore, when the drive shaft 20 rotates, the blade surface 40 can cut an object located in the opening 42. The cut object is taken into the lumen 45 of the main body 41. Alternatively, as shown in FIG. 4( b), the first surface 43 a that forms the edge of the opening 42 and the second surface 43 c that forms the inner circumferential surface 41 b of the main body 41 may intersect at an acute angle to form the blade surface 43. This allows the object to be cut while minimizing the impact on the inner wall of the blood vessel.

[0046] As shown in FIG. 5(a), which is a BB end view of FIG. 3, and FIG. 5(b), which is a CC end view of FIG. 3, the blade surface 43 may be configured such that the angle between the first surface 43a and the second surface 43b increases from the distal end to the proximal end, i.e., approaches an obtuse angle. This allows the distal portion of the blade surface 43 to have a sharp shape and be able to reliably cut an object. On the other hand, the proximal portion of the blade surface 43 has a shape that is less likely to injure tissue, since the angle between the first surface 43a and the second surface 43b is close to an obtuse angle. However, the blade surface 43 may have the same sharp cross-sectional shape from the distal end to the proximal end.

[0047] As shown in Figure 3, a flexible section 50 that is more flexible than other sections of the drive shaft 20 is provided proximal to the opening 42 of the drive shaft 20. The flexible section 50 is formed by providing a slit in the drive shaft 20 that extends in a meandering spiral shape along the circumferential direction and has a plurality of uneven shapes. However, since it is sufficient for the flexible section 50 to be more flexible than other sections of the drive shaft 20, it may be made flexible by a configuration other than the slit shape shown in Figure 3.

[0048] 6, tip end 25 of drive shaft 20 has a shape in which tip end portion 28 is asymmetric with respect to axis X. Therefore, the center of gravity of tip end portion 28 is eccentric from axis X, and tip end position 28a is away from axis X.

[0049] The operating handle 80 has a handle 81 that is held by the surgeon and an operating unit 82 that is rotatably provided at the distal end of the handle 81. As shown in FIG. 7( a), the outer tube 30 extending distally from the operating handle 80 is covered by a sheath 31. The distal end 31a of the sheath 31 is linear together with the outer tube 30 and the drive shaft 20. As shown in FIG. 7( b), by rotating the operating unit 82 of the operating handle 80, the distal end 31a of the sheath 31 is curved. As a result, the drive shaft 20 and the outer tube 30 are bent in the direction of the curve of the distal end 31a, and the distal end 25 of the drive shaft 20 can be directed in another direction. In another embodiment, the distal end of the outer tube 30 may be shaped in advance to bend in one direction and be linear when covered by the sheath 31. In this case, by rotating the operating unit 82 of the operating handle 80, the sheath 31 moves proximally, exposing the distal end of the outer tube 30. This allows the outer tube 30 to bend in a pre-configured direction, and the distal end 25 of the drive shaft 20 to point in a different direction.

[0050] A tube 85 is connected to the operating handle 80, and a three-way stopcock 86 is connected to the end of the tube 85. The tube 85 communicates with the interior of the operating handle 80. The suction lumen 21 of the drive shaft 20 is open within the operating handle 80. This allows fluid to be injected into the suction lumen 21 or fluid to be sucked out of the suction lumen 21 via the three-way stopcock 86.

[0051] A method of using the medical device 10 to cut and aspirate an object in a blood vessel will be described. The surgeon first positions the distal end of the medical device 10 near the lesion. Next, the surgeon connects the rotary drive shaft 221 of the drive device 200 to the rotary input unit 110. Subsequently, the surgeon connects the suction tube 231 to the discharge port 70. After this, the surgeon activates the drive device 200. This starts rotation of the rotary drive shaft 221 and suction of the suction tube 231. The rotary drive shaft 221 rotates the rotary input unit 110. This causes the proximal shaft 90 fixed to the rotary input unit 110 to rotate, and the drive shaft 20 rotates together with the proximal shaft 90. As described above, the rotation of the drive shaft 20 causes the blade surface 43 facing the rotation direction at the opening 42 to cut the object, and the severed blood vessel is taken into the lumen 45 of the main body 41.

[0052] As shown in FIG. 8 , when the drive shaft 20 rotates within a blood vessel 300, the distal end 25 of the drive shaft 20 bends at the flexible portion 50 so that the most distal end 28, whose center of gravity is eccentric from the axis X, faces outward, rotating like a swinging head. Note that the bent portion 50 is shaded in FIG. 8 . This allows the opening 42 of the blade surface 40 to swing over a wide range within the blood vessel 300, enabling efficient cutting of objects. When the rotation speed of the drive shaft 20 is low and the drive shaft 20 does not encounter significant resistance from the blood vessel wall or other objects, the period of rotation of the distal end 25 of the drive shaft 20 and the period of orbital revolution of the distal end 25 of the drive shaft 20 are the same. The opening 42, which includes the blade surface 43, is positioned so that it faces the opposite side of the axis X from the center of gravity of the most distal end 28. Therefore, during rotation of the drive shaft 20, the opening 42 always faces the center of rotation of the drive shaft 20. This prevents the blade surface 43 from facing the blood vessel wall. However, opening 42 may be positioned so as to face the same side as the center of gravity of distal end portion 28, in which case opening 42 can always face the blood vessel wall. Depending on the rotation speed of drive shaft 20, the state of contact with the blood vessel wall, or the state of twisting, the rotation period of the distal end of drive shaft 20 may be faster than the revolution period. In this case, opening 42 will face in various directions within blood vessel 300 while cutting the object.

[0053] The suction tube 231 applies negative pressure to the suction lumen 21 of the drive shaft 20 via the discharge port 70 and the internal space 65 of the housing 60. As a result, the material cut by the blade surface 43 of the blade surface portion 40 becomes debris, which is taken into the inner cavity 45 of the main body portion 41 and moves through the suction lumen 21 of the drive shaft 20 toward the proximal end.

[0054] The sucked debris passes through the proximal end of the drive shaft body 22 and reaches the proximal opening 26, which is a side hole. The debris that reaches the proximal opening 26 is discharged from the proximal opening 26 into the internal space 65 of the housing 60. The debris discharged into the internal space 65 is discharged into the suction tube 231 via the discharge port 70.

[0055] The debris discharged to the outside from the discharge port 70 reaches the pump 232 through the suction tube 231. The debris that reaches the pump 232 is discharged into the waste fluid pack 235. After cutting of the lesion and suction of the debris are completed, the surgeon stops the operation of the drive device 200. This stops the rotation of the drive shaft 20 and stops the suction of the pump 232. This stops the cutting of the object by the blade surface portion 40 and the discharge of the debris. Thereafter, the medical device 10 is removed from the blood vessel, completing the treatment.

[0056] Modified examples of the blade surface portion will be described. As shown in Fig. 9(a), an opening 130 formed in the cylindrical main body 41 may have a first opening edge 130a and a second opening edge 130b extending in a direction parallel to the axis X of the drive shaft 20, and a blade surface 131 may be formed on the second opening edge 130b. As shown in Fig. 9(b), an opening 132 formed in the cylindrical main body 41 may have a first opening edge 132a extending in a direction parallel to the axis X of the drive shaft 20 and a second opening edge 132b extending in a direction non-parallel to the axis X, and a blade surface 133 may be formed on the second opening edge 132b. As shown in Fig. 9(c), an opening 134 formed in the cylindrical main body 41 may have a first opening edge 134a and a second opening edge 134b extending in a direction parallel to the axis X of the drive shaft 20, and a blade surface 135 and a notch 136 may be formed on the second opening edge 134b. The notch 136 is continuous in a curved shape from the notch distal edge 136a to the notch proximal edge 136b. In this case, the tip of the second opening edge 134b intersects with the notch proximal edge 136b of the notch 136 to form an end 135a. The end 135a forms an acute angle where the blade surface 135 intersects with the notch proximal edge 136b.

[0057] As shown in Fig. 10(a), the main body 46 may have a truncated cone shape with an outer diameter that decreases toward the tip. The opening 140 may have a first opening edge 140a and a second opening edge 140b that extend in a direction non-parallel to the axis X of the drive shaft 20, and a blade surface 141 and a notch 142 may be formed on the second opening edge 140b. The notch 142 is curved and continues from the notch distal edge 142a to the notch proximal edge 142b. In this case, the tip of the second opening edge 140b intersects with the notch proximal edge 142b of the notch 142, forming a sharp end 141a. 10(b), main body 46 formed in a truncated cone shape may have a first opening edge 144a extending in a direction non-parallel to axis X of drive shaft 20 and a second opening edge 144b extending in a direction parallel to axis X, and blade surface 145 may be formed on second opening edge 144b. As shown in FIG. 10(c), main body 46 formed in a truncated cone shape may have a first opening edge 146a and a second opening edge 146b extending in a direction non-parallel to axis X of drive shaft 20, and blade surface 147 may be formed on second opening edge 146b.

[0058] As shown in FIG. 11 , the blade surface 43 is formed so as to face in the circumferential direction of the main body portion 41, but the blade surface portion 40 may have a blade surface 43′ that faces more toward the outer periphery of the main body portion 41 in the circumferential direction. In this case, the blade surface 43′ is more likely to cut an object positioned in the opening 42. Alternatively, the blade surface portion 40 may have a blade surface 43″ that faces more toward the inner periphery of the main body portion 41 in the circumferential direction. In this case, the blade surface 43″ is less likely to come into contact with the blood vessel wall.

[0059] While the above-described embodiment and modified examples have been described with a blade surface on one side of the opening, blade surfaces may be provided on both sides of the opening, as shown in FIG. 12 . For example, as shown in FIG. 12 , an opening 150 formed in a cylindrical main body 41 has a first opening edge 150a and a second opening edge 150b, each extending in a direction non-parallel to the axis X of the drive shaft 20. A first blade surface 155 and a first notch 154 are formed on the first opening edge 150a. A second blade surface 151 and a second notch 152 are formed on the second opening edge 150b. The first notch 154 extends in a curved manner from a first notch distal edge 154a to a first notch proximal edge 154b. In this case, a sharp first end 155a is formed on the distal side of the first opening edge 150a as the intersection of the first notch 154 and the first notch proximal edge 154b. The first end 155a forms an acute angle where the first blade surface 155 and the first cutout proximal edge 154b intersect. The second cutout 152 is continuous in a curved shape from the second cutout distal edge 152a to the second cutout proximal edge 152b. In this case, a sharp second end 151a is formed on the distal side of the second opening edge 150b as an intersection with the second cutout proximal edge 152b of the second cutout 152. The second end 151a forms an acute angle where the second blade surface 151 and the second cutout proximal edge 152b intersect.

[0060] 13, which shows the AA end surface and the BB end surface in FIG. 12, in the AA end surface, the first notch 154 and the second notch 152 are positioned symmetrically with respect to a plane that vertically crosses the central axis X in a front view. In the BB end surface, the first end 155a and the second end 151a are positioned symmetrically with respect to a plane that vertically passes through the central axis X in a front view. In the modified example of the blade surface portion shown in FIGS. 12 and 13, the drive shaft 20 is periodically reversed, so that the first blade surface 155 or the second blade surface 151 facing in the rotation direction cuts an object, and the cut object is taken into the lumen 45 of the main body 41.

[0061] An embodiment in which blade surfaces are provided on both sides of the opening may be as shown in Figure 14. That is, the opening 160 formed in the cylindrical main body 41 has a first opening edge 160a and a second opening edge 160b that extend in a direction non-parallel to the axis X of the drive shaft 20. A first blade surface 165 and a first cutout 164 are formed on the first opening edge 160a. The first opening edge 160a and the second opening edge 160b extend spirally at a constant distance from each other in the circumferential direction. A second blade surface 161 and a second cutout 162 are formed on the second opening edge 160b. The first cutout 164 is curved from a distal edge 164a of the first cutout to a proximal edge 164b of the first cutout. In this case, a sharp first end 165a is formed on the distal end side of the first opening edge 160a as an intersection with the first notch proximal edge 164b of the first cutout 164. The first end 165a forms an acute-angled end where the first blade surface 165 and the first notch proximal edge 164b intersect. The second cutout 162 is curved from the second notch distal edge 162a to the second notch proximal edge 162b. In this case, a sharp second end 161a is formed on the proximal end side of the second opening edge 160b as an intersection with the second notch distal edge 162a of the second cutout 162. The second end 161a forms an acute-angled end where the second blade surface 161 and the second notch distal edge 162a intersect.

[0062] The AA end surface and the BB end surface in Figure 14 are shown in Figure 15. At the AA end surface, a sharp first end 165a is formed in the direction of clockwise rotation (direction of the arrow) around the central axis X. At the BB end surface, a sharp second end 161a is formed in the direction of counterclockwise rotation (direction of the arrow) around the central axis X. In the modified example of the blade surface portion shown in Figures 13 and 14, the drive shaft 20 is periodically reversed, so that the first blade surface 165 or the second blade surface 161 facing the rotation direction cuts an object, and the cut object is taken into the lumen 45 of the main body 41.

[0063] As described above, the medical device 10 according to the present embodiment (1) includes a drive shaft 20 having a distal end portion 25 and rotatable about an axis X, and a blade surface portion 40 attached to the distal end portion 25 and configured to rotate with rotation of the drive shaft 20 to cut an object, the blade surface portion 40 comprising a hollow main body portion 41 having a circumferential surface 41a, the main body portion 41 including an opening 42 formed in the circumferential surface 41a to connect the hollow interior to the outside, and a blade surface 43 sharpened in the direction of rotation of the opening 42. The medical device 10 configured in this manner includes a sharp blade surface 43 at the opening 42 that connects the inside and outside of the main body portion 41 that forms the blade surface portion 40. As the drive shaft 20 rotates, the blade surface 43 can cut and shred an object located at the opening 42 and introduce it into the main body portion 41, thereby enabling the object to be efficiently cut and removed.

[0064] (2) In the medical device 10 described in (1) above, the main body 41 may be cylindrical. This allows the opening 42 of the medical device 10 to be wide open from the distal end to the proximal end, making it easier to take in an object.

[0065] (3) In the medical device 10 described in (1) above, the main body 46 may be frustoconical. This allows the outer diameter of the distal end of the main body 46 of the medical device 10 to be reduced, making it easier to insert the distal end of the medical device 10 into a blood vessel.

[0066] (4) In the medical device 10 of any of (1) to (3) above, the blade surface 43 may extend in a direction non-parallel to the axial direction X of the drive shaft 20. This makes it easier for the medical device 10 to cut an object with the blade surface 43, since the blade surface 43 is angled with respect to the rotation direction of the drive shaft 20.

[0067] (5) In the medical device 10 of any of (1) to (4) above, the blade surface 43 may be provided so as to be inclined in the circumferential direction about the axis X in the opposite direction to the rotational direction toward the base end side of the axis X. This allows the medical device 10 to easily cut an object caught in the distal end portion of the opening 42 with the blade surface 43.

[0068] (6) In the medical device 10 described in (5) above, the blade surface 43 may be provided in a circumferential direction about the axis X, such that when the medical device 10 rotates in one direction around the axis X as viewed from the distal end in the direction of the axis X, the blade surface 43 extends in the other direction around the axis X toward the proximal end. This allows the medical device 10 to cut an object from the distal end toward the proximal end as the drive shaft 20 rotates, thereby more reliably cutting the object.

[0069] (7) In the medical device 10 described in (6) above, the blade surface 43 may be spiral in the circumferential direction around the axis X, extending in a direction around the other side toward the base end of the axis X. This allows the medical device 10 to more easily cut an object with the spiral-shaped blade surface 43.

[0070] (8) In the medical device 10 of any of (1) to (3) above, the blade surface 131 may extend in a direction parallel to the axial direction X of the drive shaft 20. This allows the circumferential position of the blade surface 131 in the medical device 10 to be constant along the axial direction X, thereby preventing the blade surface 131 from coming into contact with a blood vessel wall or the like.

[0071] (9) In the medical device 10 of any of (1) to (8) above, the opening 42 may have a notch 44 that separates the distal edge of the opening 42 from the tip of the blade surface 43, and the tip of the blade surface 43 may have a sharp end 43c. This allows the medical device 10 to pierce an object with the sharp end 43c formed at the tip of the blade surface 43, thereby more reliably cutting the object.

[0072] The medical device (10) according to this embodiment includes a drive shaft (20) having a tip (25) and rotatable about an axis (X), and a blade surface (40) provided on the tip (25) and rotating with the rotation of the drive shaft (20) to cut an object, the blade surface (40) having a main body (41) with a space therein, the main body (41) having an opening (42) that is open so that an object can be taken into the space and has a pair of opening edges (42a, 42b) that are parallel or non-parallel to the axis (X) direction of the drive shaft (20), and one of the pair of opening edges (42a, 42b) is a sharp blade surface (43).

[0073] (11) In the medical device 10 described in (10) above, the blade surface 43 may be provided so as to be inclined in the circumferential direction about the axis X toward the base end of the axis X in the opposite direction to the rotation direction of the drive shaft 20. This allows the medical device 10 to easily cut an object caught in the distal end portion of the opening 42 with the blade surface 43.

[0074] (12) In the medical device 10 of (10) or (11) above, the opening 42 may have a notch 44 that separates the leading edge of the opening 42 from the tip of the blade surface 43, and the tip of the blade surface 43 may have a sharp edge 43c. This allows the medical device 10 to pierce an object with the sharp edge 43c formed at the tip of the blade surface 43, thereby more reliably cutting the object.

[0075] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical spirit of the present invention. For example, the biological lumen into which the medical device 10 is inserted is not limited to a blood vessel, but may be, for example, a vascular tract, a ureter, a bile duct, a fallopian tube, a hepatic duct, etc. Furthermore, the medical device 10 and the driving device 200 may be integrally configured.

[0076] Furthermore, the suction force may be generated by the drive shaft instead of the suction unit 230 connected to the discharge port 70. If the drive shaft has the structure of an archimedes screw pump, it can generate suction force by rotating. In this case, the discharge port 70 can discharge debris even if it is not connected to the suction unit 230 that generates the suction force. [Explanation of symbols]

[0077] 10 Medical Devices 20 Drive shaft 21 suction lumens 25 Tip 26 Proximal opening 28 Cutting edge section 30 outer tube 31 Sheath 35 Inner tube 40 Blade surface part 41 Main body 41a Circumferential surface 42 Opening 42a First opening edge 42b Second opening edge 43 Blade surface 43a end 44 Notch 45 Lumen 50 Flexible part 60 Housing 80 Operating handle 110 Rotation input section 200 Drive Devices

Claims

1. a shaft having a tip and rotatable about an axis; a blade surface portion provided at the tip portion and rotating with rotation of the shaft to cut an object, The blade surface portion includes a hollow main body portion having a peripheral surface, The medical device includes an opening provided on the circumferential surface of the main body portion that connects the hollow interior with the outside, and a blade surface that is sharp in the rotational direction of the opening.

2. The medical device of claim 1 , wherein the body portion is cylindrical.

3. The medical device of claim 1 , wherein the body portion is frustoconical.

4. The medical device of claim 1 , wherein the cutting edge extends along a direction non-parallel to the axial direction of the shaft.

5. The medical device according to claim 1 , wherein the blade surface is provided so as to be inclined in a circumferential direction around the shaft toward the base end of the shaft in a direction opposite to the rotation direction.

6. 6. The medical device according to claim 5, wherein the blade surface is arranged so that when rotating in one direction around the axis as viewed from the axial tip side, the blade surface extends along the other direction around the axis toward the base end side of the axis.

7. The medical device according to claim 6 , wherein the blade surface is spiral in a circumferential direction around the shaft toward the base end side of the shaft.

8. The medical device according to claim 1 , wherein the cutting edge extends along a direction parallel to the axial direction of the shaft.

9. the opening has a notch that separates a leading edge of the opening from the most distal end of the blade surface, The medical device of claim 1 , wherein the cutting edge has a sharpened edge at a leading edge of the cutting surface.

10. a shaft having a tip and rotatable about an axis; a blade surface portion provided at the tip portion and rotating with rotation of the shaft to cut an object, The blade surface portion includes a main body portion having a space therein, the main body portion includes an opening that is open so that the object can be taken into the space and has a pair of opening edges that are parallel or non-parallel to the axial direction of the shaft, A medical device, wherein at least one of the pair of opening edges is a sharp blade surface.

11. The medical device according to claim 10 , wherein the blade surface is provided so as to be inclined in a circumferential direction around the axis toward the base end side of the axis in a direction opposite to the rotation direction of the shaft.

12. the opening has a notch that separates a leading edge of the opening from the most distal end of the blade surface, The medical device of claim 10 or 11, wherein the cutting edge has a sharp edge at the most distal end of the cutting surface.

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