Medical device

Abstract

To provide a medical device which suctions substances in a living body lumen, suppresses accumulation of the substance in the device, and effectively discharges the substance.SOLUTION: A medical device for removing substances inside a living body lumen includes a rotatable drive shaft 20 having a lumen, a cutting part which is fixed to a distal part of the drive shaft for cutting the substance, a rotatable proximal shaft which is arranged in a part closer to a proximal side than the drive shaft, a connecting part 100 which connects the proximal shaft and the drive shaft and can transmit torque of the proximal shaft to the drive shaft, and a housing which rotatably houses the connecting part, and in which a discharge port for discharging the cut substance to the outside is formed. The connecting part includes a spiral site and a central passage P which is surrounded by the spiral site and communicates with the lumen of the drive shaft.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Methods for treating stenosis caused by plaque or thrombus in blood vessels include expanding blood vessels 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 treat stenosis that has hardened due to calcification or that occurs at the branching part of blood vessels. One method that can treat such cases is to cut and remove the stenosis such as plaque or thrombus.

[0003] For example, Patent Document 1 describes a device in which an operating head for cutting an object is fixed to the distal part of a drive shaft. This device can cut an object with the operating head by rotating the drive shaft. This device has a housing with an exhaust port for applying suction force at hand. The debris formed by cutting is sucked into the lumen from the distal opening of the drive shaft and moved to the proximal side. The debris then moves from the proximal opening of the drive shaft into the housing and is discharged from the exhaust port. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application No. 2018 / 0353199 Summary of the Invention [Problem to be solved by the invention]

[0005] Debris tends to wrap around the drive shaft as it rotates within the housing, and if debris blocks the proximal opening of the drive shaft, the debris remains within the housing and is difficult to expel through the exhaust port.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a medical device that can suck up objects in a biological lumen, prevent the objects from remaining within the device, and effectively expel the objects. [Means for solving the problem]

[0007] The medical device of the present invention, which achieves the above-mentioned objective, is a medical device for removing objects within a biological lumen, and comprises a rotatable drive shaft having an inner lumen, a cutting section fixed to a distal portion of the drive shaft and cutting objects, a rotatable proximal shaft arranged proximal to the drive shaft, a connection section connecting the proximal shaft and the drive shaft and capable of transmitting the rotational force of the proximal shaft to the drive shaft, and a housing that rotatably accommodates the connection section and has an exhaust port formed therein for exhausting the cut object to the outside, wherein the connection section has a spiral-shaped portion and a central passage surrounded by the spiral-shaped portion and communicating with the inner lumen of the drive shaft. Effect of the Invention

[0008] In the medical device configured as described above, objects flowing proximally through the inner cavity of the drive shaft are less likely to become entangled with the rotating connection. This prevents the proximal opening of the drive shaft from being completely blocked by objects. Thus, the medical device can suck in objects from the body lumen, prevent the objects from remaining in the device, and effectively expel the objects. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view showing a medical device and a drive device according to the first embodiment. [Diagram 2] 1 is a cross-sectional view showing a proximal portion of a medical device according to a first embodiment. [Diagram 3]1A and 1B are partially transparent views of the vicinity of a connection portion of a medical device according to a first embodiment, where (A) is a plan view, (B) is a cross-sectional view taken along line AA in (A), and (C) is a cross-sectional view taken along line BB in (A). [Figure 4] 1 is a cross-sectional view showing a distal portion of a medical device according to a first embodiment. [Diagram 5] FIG. 11 is a partially see-through view of the vicinity of a connection portion of a medical device according to a second embodiment, where (A) is a plan view and (B) is a cross-sectional view taken along line CC of (A). [Figure 6] FIG. 11 is a partially see-through plan view showing the vicinity of a connection portion of a medical device according to a third embodiment. [Figure 7] 13A and 13B are diagrams showing a modified example of a connection portion, in which (A) is a plan view and (B) is a cross-sectional view taken along line EE of (A). [Figure 8] 13A and 13B are diagrams showing another modified example of the connection portion, in which (A) is a plan view and (B) is a cross-sectional view taken along line FF in (A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the size and ratio of each component in the drawings may be exaggerated for the sake of explanation and may differ from the actual size and ratio.

[0011] First Embodiment The medical device 10 according to the first embodiment is inserted into a blood vessel in acute lower limb ischemia or deep vein thrombosis, and is used in a procedure for destroying and removing objects such as thrombus, plaque, atheroma, and calcified lesions. 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 hand is referred to as the "proximal side." Note that the objects to be removed are not necessarily limited to thrombus, plaque, atheroma, and calcified lesions, and may be any object that may exist in a biological lumen.

[0012] As shown in Figs. 1 and 2, the medical device 10 is coupled to and driven by a driving device 200 that generates a driving force and a suction force. The medical device 10 includes a long drive shaft 20 that is rotatably driven, an outer tube 30 that houses the drive shaft 20, and a cutting section 40 that cuts an object. The medical device 10 further includes an inner tube 50 that is disposed inside the drive shaft 20, a proximal shaft 90 that is disposed proximal to the drive shaft 20, and a connection section 100 that connects the proximal shaft 90 to the drive shaft 20. The medical device 10 further includes a housing 60 that rotatably holds a proximal section of the drive shaft 20, and a rotation input section 110 that receives a rotational force from the drive device 200.

[0013] The drive shaft 20 transmits the rotational force to the cutting part 40. The drive shaft 20 is formed with an aspiration lumen 21 (inner cavity) for moving the cut object to the proximal side. The drive shaft 20 includes a long drive shaft body 22 and an auxiliary member 23 fixed to the proximal part of the drive shaft body 22. The drive shaft 20 passes through an outer tube 30, and the cutting part 40 is fixed to the distal part. The proximal part of the drive shaft 20 is located inside the housing 60. The drive shaft 20 is connected to a proximal shaft 90 via a connecting part 100. The drive shaft 20 has a distal opening 26 at its distal end, where the aspiration lumen 21 opens. The distal opening 26 is an entrance through which debris, which is an object to be cut and sucked, enters. The drive shaft 20 has a proximal opening 25 at its proximal end. The proximal opening 25 is an exit through which debris that has entered the inside of the drive shaft 20 from the distal opening 26 is discharged. The proximal opening 25 opens toward the proximal side.

[0014] The drive shaft body 22 is flexible and has the property of being able to transmit rotational power acting from the proximal side to the distal side. The drive shaft body 22 is rotatably supported inside the housing 60 by a first bearing 67, which will be described later. Therefore, the drive shaft body 22 can rotate smoothly at high speed.

[0015] The auxiliary member 23 has a cylindrical shape, and the proximal portion of the drive shaft body 22 is inserted from the opening on the distal side. Furthermore, the auxiliary member 23 has the connection portion 100 inserted from the opening on the proximal side. The inner diameter of the auxiliary member 23 is approximately the same as the outer diameter of the drive shaft body 22. Therefore, the drive shaft body 22 fits inside the auxiliary member 23. Therefore, the drive shaft body 22 and the auxiliary member 23 are stably connected. The proximal end surface 27 of the auxiliary member 23 is the proximal end surface of the drive shaft 20, and is ring-shaped. The proximal end surface 27 of the auxiliary member 23 is the surface of the auxiliary member 23 on the proximal side facing the axial direction. Note that the drive shaft body 22 may be connected to the connection portion 100 without the auxiliary member 23. That is, the drive shaft 20 may be constituted by the drive shaft body 22, and may not have the auxiliary member 23.

[0016] A rotation input portion 110 that receives a rotational force from the drive device 200 is fixed to a proximal portion of the proximal shaft 90. The proximal portion of the proximal shaft 90 protrudes from the housing 60 to the proximal side. The proximal shaft 90 is rotatably supported inside the housing 60 by a second bearing 68, which will be described later. For this reason, the proximal shaft 90 can rotate smoothly at high speed.

[0017] As shown in Figures 2 and 3, the connection part 100 is a member that connects the drive shaft 20 on the distal side and the proximal shaft 90 on the proximal side. The connection part 100 is connected to the drive shaft 20 without blocking the proximal opening 25 of the drive shaft 20 that opens toward the proximal side. The connection part 100 extends toward the proximal side from the drive shaft 20 to which it is connected. Note that, although the connection part 100 is formed integrally with the proximal shaft 90 in this embodiment, it may be formed separately from the proximal shaft 90.

[0018] The connecting part 100 has a generally cylindrical shape, and one spiral groove 101 is formed on the outer circumferential surface. The connecting part 100 includes a spiral proximal part 104 located on the proximal side and having a large outer diameter, and a spiral distal part 105 located on the distal side of the spiral proximal part 104 and having a smaller outer diameter than the spiral proximal part 104. A step part 106 in which the outer diameter changes in a step-like manner is formed between the spiral distal part 105 and the spiral proximal part 104. The step part 106 abuts against the proximal end face 27 of the drive shaft 20. The shape of the end face of the step part 106 of the connecting part 100 abutting against the proximal end face 27 of the drive shaft 20 is different from the shape of the proximal end face 27 of the drive shaft 20. The cross-sectional shape of the connecting part 100 on the surface where the proximal end face 27 of the drive shaft 20 is located is different from the shape of the proximal end face 27. Therefore, the connection part 100 can be fixed to the proximal part of the drive shaft 20 without blocking the axial opening of the proximal opening 25 of the drive shaft 20. The surface on which the proximal end surface 27 of the drive shaft 20 is located is preferably a flat surface, but may not be a flat surface, and may be, for example, a curved surface or a bent surface. The connection part 100 may be formed with a constant outer diameter without being divided into the spiral proximal part 104 and the spiral distal part 105. For example, the connection part 100 may be formed with an outer diameter that can enter the proximal opening 25 without including the step part 106. In this case, the connection part 100 does not include the step part 106 (end surface) that abuts against the proximal end surface 27, and enters the proximal opening 25 and is fixed to the drive shaft 20.

[0019] The distal end surface 107 of the spiral distal portion 105 abuts against the proximal end surface 28 of the drive shaft body 22 inside the auxiliary member 23. Note that the distal end surface 107 of the spiral distal portion 105 and the proximal end surface 28 of the drive shaft body 22 do not have to abut against each other.

[0020] The outer diameter of the proximal spiral portion 104 is approximately the same as the outer diameter of the auxiliary member 23, but may not be the same. The outer diameter of the distal spiral portion 105 is approximately the same as the inner diameter of the auxiliary member 23. Therefore, the distal spiral portion 105 fits into the inner cavity of the auxiliary member 23, and the distal spiral portion 105 is stably connected to the auxiliary member 23. The step portion 106 abuts against the proximal end surface 27 of the auxiliary member 23. This allows the connection portion 100 and the auxiliary member 23 to be stably connected in the axial direction. Note that the connection portion 100 is formed separately from the auxiliary member 23, but may be formed integrally with the auxiliary member 23. That is, the auxiliary member 23, which is a part of the drive shaft 20, may be formed integrally with the connection portion 100. Even in this case, a cylindrical shape having a proximal opening 25 can be specified as the auxiliary member 23. That is, the drive shaft 20 is formed from the proximal end of the portion in which the inner wall surface is formed over 360 degrees and surrounds the entire internal space. The proximal opening 25 opens in the axial direction from the proximal end of the portion where the inner wall surface is formed over 360 degrees. Therefore, the proximal surface 28 of the auxiliary member 23 can be located inside the member that is integrally formed.

[0021] Furthermore, when drive shaft 20 does not have auxiliary member 23, the proximal end surface of drive shaft 20 is proximal end surface 28 of drive shaft body 22 and is ring-shaped. The cross-sectional shape of connection part 100 in the plane where proximal end surface 28 of drive shaft body 22 is located (the shape of distal end surface 107) is different from the shape of proximal end surface 28.

[0022] The spiral groove 101 is formed on the outer circumferential surface of the connecting part 100, spiraling from the distal end surface 107 of the connecting part 100 toward the proximal side. The spiral groove 101 communicates with the suction lumen 21 of the drive shaft 20 at the distal end surface 107 of the connecting part 100. The spiral groove 101 does not need to be formed to the proximal end surface of the connecting part 100, but may be formed to the proximal end surface. The spiral direction of the spiral groove 101 is the direction in which an object inside the spiral groove 101 receives a force toward the proximal side when the connecting part 100 rotates due to a rotational force transmitted from the drive device 200. For example, when viewed from the proximal side to the distal side, if the rotation direction of the connecting part 100 is clockwise, the winding direction of the spiral groove 101 of the connecting part 100 is clockwise toward the distal side. When viewed from the proximal side to the distal side, when the rotation direction of the connection part 100 is counterclockwise, the winding direction of the spiral groove 101 of the connection part 100 is counterclockwise toward the distal side. The depth H of the spiral groove 101 from the outer circumferential surface of the connection part 100 toward the central axis X is not particularly limited, but is, for example, greater than the distance R from the outer circumferential surface of the connection part 100 to the central axis X. As a result, in the axis-orthogonal cross section (cross section perpendicular to the central axis X) of the connection part 100, a central passage P (see the two-dot chain line in FIG. 3) is formed that extends linearly along the central axis X of the connection part 100. That is, a central passage P that surrounds the central axis X is formed at the center of the connection part 100, and no material of the connection part 100 exists on the central axis X. Therefore, the suction lumen 21 of the drive shaft 20 and the central passage P of the connection part 100 communicate linearly along the central axis X. The depth H of the spiral groove 101 may be equal to or less than the distance R of the connection portion 100 .

[0023] The helical angle θ of the helical groove 101 with respect to the central axis X is not particularly limited, but is, for example, 1 to 89°, preferably 10 to 60°, and more preferably 20 to 50°. If the angle θ is too close to 90°, it becomes difficult for debris to pass through the helical groove 101. If the angle θ is too close to 0°, the force of the rotating helical groove 101 to transport debris to the proximal side becomes weak. The helical angle θ may change along the central axis X of the connection part 100. For example, the helical angle θ may be close to 0° on the distal side of the connection part 100 and closer to 90° toward the proximal side. This allows the helical groove 101 to move debris smoothly.

[0024] The material of the drive shaft body 22 is not particularly limited, but suitable materials include, for example, stainless steel, Ta, Ti, Pt, Au, W, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluoropolymers such as ETFE, PEEK (polyether ether ketone), polyimide, etc. Also, the drive shaft body 22 may be made of a plurality of materials, and a reinforcing member such as a wire may be embedded in the body.

[0025] The constituent materials of the auxiliary member 23, the connection part 100, and the proximal shaft 90 are not particularly limited, and for example, stainless steel, Ta, Ti, Pt, Au, W, shape memory alloys, etc. may be suitably used. The constituent materials of the auxiliary member 23, the connection part 100, and the proximal shaft 90 may be resins such as engineering plastics such as polyether ether ketone (PEEK).

[0026] 2, the rotation input unit 110 is a substantially cylindrical member fixed to the proximal end of the drive shaft 20. The rotation input unit 110 is a member that is coupled to the rotation drive shaft 221 of the drive device 200 to receive rotational power. The proximal portion of the rotation input unit 110 is provided with a fitting recess 111 into which the rotation drive shaft 221 fits.

[0027] As shown in Figs. 2 and 4, the inner tube 50 is a flexible tube and is disposed inside the drive shaft 20. The inner tube 50 prevents the inner peripheral surface of the drive shaft 20 from being damaged by debris flowing inside the drive shaft 20. The inner tube 50 may be fixed to the inner peripheral surface of the drive shaft 20, but may not be fixed. The radius R1 of the outer peripheral surface of the inner tube 50 is greater than the distance D from the central axis X to the closest part of the connection part 100 at the distal end surface 107 of the connection part 100, as shown in Fig. 3(C). In addition, the distance D is greater than the radius R2 of the inner peripheral surface of the drive shaft body 22. Therefore, a part of the distal end surface 107 of the connection part 100 is located radially inward from the inner peripheral surface of the drive shaft body 22. Therefore, when the inner tube 50 moves proximally inside the inside of the suction lumen 21, the proximal end surface of the inner tube 50 comes into contact with the distal end surface 107 of the connection part 100. This prevents the inner pipe 50 from entering the spiral groove 101 of the connection portion 100. It is to be noted that the inner pipe 50 does not necessarily have to be provided.

[0028] As shown in FIGS. 1, 2 and 4, the outer tube 30 includes an outer tube body 31 that rotatably houses the drive shaft 20, and a distal tube 32 that is fixed to the side surface of the distal portion of the outer tube body 31.

[0029] The outer tube body 31 is a flexible tubular body, and a proximal portion is fixed to the housing 60. A distal portion of the outer tube body 31 is located proximal to the cutting portion 40. The distal tube 32 is a flexible tubular body, and is fixed to the outer circumferential surface of the distal portion of the outer tube body 31. The distal tube 32 has a guidewire lumen 33 into which a guidewire can be inserted.

[0030] As shown in Figs. 1 and 4, the cutting part 40 is a member that cuts and reduces objects such as thrombus, plaque, and calcified lesions. Therefore, "cutting" means applying a force to an object in contact with it to reduce the size of the object. The method of applying the force in cutting and the shape and form of the object after cutting are not limited. The cutting part 40 has the strength to cut the above-mentioned objects. The cutting part 40 is fixed to the outer circumferential surface of the distal part of the drive shaft 20. The proximal end surface of the cutting part 40 may be fixed to the distal end surface of the drive shaft 20. The cutting part 40 is a cylinder that protrudes distally from the drive shaft 20. The distal end of the cutting part 40 is provided with a sharp blade 41. The shape of the blade 41 is not particularly limited. The cutting part 40 may have a large number of minute abrasive grains instead of the blade 41.

[0031] As shown in Figures 1 and 2, the housing 60 has a first portion 61 located on the distal side, a second portion 62 located approximately in the center, and a third portion 63 located on the proximal side.

[0032] The first portion 61 is connected to a distal portion of the second portion 62. A first seal portion 64 that seals the internal space is disposed between the first portion 61 and the second portion 62. The first portion 61 defines a first internal space 65 through which the drive shaft 20 rotatably passes. A proximal portion of the outer tube body 31 is fixed to an inner circumferential surface on the distal side of the first internal space 65.

[0033] The second part 62 is located proximal to the first part 61. The second part 62 has a second internal space 66 through which the drive shaft 20, the connection part 100 and the proximal shaft 90 rotatably pass. The second part 62 has an exhaust port 69 to which a suction tube 231 of the drive device 200 described later can be connected. The flow path of the exhaust port 69 communicates with the second internal space 66. A first bearing 67 and a second bearing 68 are arranged on the inner peripheral surface of the second internal space 66. The inner peripheral surface of the first bearing 67 is in contact with the outer peripheral surface of the proximal part of the drive shaft 20. The inner peripheral surface of the second bearing 68 is in contact with the outer peripheral surface of the distal part of the proximal shaft 90. Therefore, the drive shaft 20, the connection part 100 and the proximal shaft 90 are rotatably supported by the first bearing 67 and the second bearing 68, and can rotate smoothly at high speed. The positions at which the first bearing 67 and the second bearing 68 are arranged are not limited. For example, the first bearing 67 and / or the second bearing 68 may be fixed to the outer circumferential surface of the connection part 100. Also, the first bearing 67 and / or the second bearing 68 may not be provided.

[0034] The third portion 63 is connected to a proximal portion of the second portion 62. The third portion 63 has a third internal space 71 through which the proximal shaft 90 rotatably passes. A second seal portion 70 that seals the second internal space 66 is disposed between the second portion 62 and the third portion 63. The second seal portion 70 contacts the outer circumferential surface of the proximal shaft 90 to seal between the second portion 62 and the proximal shaft 90.

[0035] The proximal opening 25 of the drive shaft 20 is located in the second internal space 66. Therefore, the negative pressure acting on the discharge port 69 from the suction tube 231 acts on the inside of the drive shaft 20 from the proximal opening 25. The first seal portion 64 and the second seal portion 70 suppress the negative pressure in the first internal space 65 and the second internal space 66 from escaping. At least a part of the junction portion 72 where the flow path of the discharge port 69 connects to the second internal space 66 is preferably in the range S where the spiral groove 101 exists in the axial direction of the connection portion 100, as shown in FIG. 3(A). The junction portion 72 is a portion of the inner surface forming the flow path of the discharge port 69 that connects to the inner surface forming the second internal space 66. The junction portion 72 is preferably close to the proximal opening 25. The junction portion 72 may partially overlap the proximal opening 25 in the axial direction of the connection portion 100. Also, it is preferable that at least a portion of the confluence 72 is located proximal to the proximal opening 25 of the drive shaft 20 in the axial direction of the connection part 100. The position of the confluence 72 is not limited to the above-mentioned range. Also, the position of the proximal opening 25 of the drive shaft 20 is not particularly limited as long as negative pressure from the exhaust port 69 can act thereon.

[0036] Next, the driving device 200 will be described. As shown in FIG. 1, the drive device 200 includes a drive section 220 that generates a rotational force, and a suction section 230 that generates a suction force.

[0037] 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.

[0038] 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 69 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 to the waste fluid pack 235.

[0039] 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.

[0040] Next, a method of using the medical device 10 according to the first embodiment will be described taking as an example a case where a lesion such as a thrombus or a calcified lesion in a blood vessel is destroyed and aspirated.

[0041] First, the surgeon inserts a guidewire (not shown) into a blood vessel and reaches the vicinity of the lesion. Next, the surgeon inserts the proximal end of the guidewire into the guidewire lumen 33 of the medical device 10. Thereafter, the surgeon uses the guidewire as a guide to reach the vicinity of the lesion.

[0042] Next, the surgeon connects the rotary drive shaft 121 of the drive device 200 to the rotary input unit 110 as shown in FIG. 2. Next, the surgeon connects the suction tube 231 to the exhaust port 69. After this, the surgeon operates the drive device 200. This starts the rotation of the rotary drive shaft 121 and the suction of the suction tube 231. The rotary drive shaft 121 rotates the rotary input unit 110. This causes the proximal shaft 90 fixed to the rotary input unit 110 to rotate, and the connection unit 100, the drive shaft 20, and the cutting unit 40 to rotate together with the proximal shaft 90. The rotating cutting unit 40 cuts the lesion in the blood vessel.

[0043] The suction tube 231 applies negative pressure to the second internal space 66 through the exhaust port 69. Thus, negative pressure is applied to the suction lumen 21 of the drive shaft 20 from the proximal opening 25 located in the second internal space 66. Therefore, as shown in FIG. 4, the lesion cut by the blade 41 of the cutting portion 40 becomes debris and moves inside the cutting portion 40 toward the proximal end. The debris is sucked into the suction lumen 21 from the distal opening 26 of the drive shaft 20.

[0044] The aspirated debris passes through the proximal end of the drive shaft body 22 and reaches the helical groove 101 of the distal helical portion 105 inside the auxiliary member 23, as shown in FIGS. 2 and 3. The debris inside the helical groove 101 receives a proximal force from the wall surface of the rotating helical groove 101 and is pushed proximally. As a result, some of the debris moves smoothly proximally through the helical groove 101 of the distal helical portion 105 and moves to the helical groove 101 of the proximal helical portion 104. Also, some of the debris may be released directly into the second internal space 66 from the proximal opening 25 that opens proximally, without passing through the helical groove 101 of the proximal helical portion 104.

[0045] The helical groove 101 of the helical proximal part 104 is not covered by the auxiliary member 23. Therefore, the helical groove 101 of the helical proximal part 104 is not covered by the auxiliary member 23 and is open to the radially outward. The debris that has moved to the helical groove 101 of the helical proximal part 104 moves from the helical groove 101 to the radially outward direction of the helical proximal part 104 and moves to the second internal space 66 surrounding the connection part 100. The debris that has moved to the second internal space 66 surrounding the connection part 100 passes through the junction 72, enters the flow path of the discharge port 69, and is discharged to the suction tube 231. At this time, the debris is smoothly discharged from the helical groove 101 to the second internal space 66, so it is difficult for it to wrap around the connection part 100 having the helical groove 101. Therefore, the proximal opening 25 and the helical groove 101, which are the debris discharge ports, are difficult to be blocked by the debris. Therefore, the debris is less likely to remain in the second internal space 66, and flows smoothly to be discharged from the discharge port 69 to the outside. Moreover, the junction 72 is in the range S in which the spiral groove 101 exists in the axial direction of the connection part 100. Furthermore, at least a part of the junction 72 is located proximal to the proximal opening 25. Therefore, the debris discharged from the proximal opening 25 and the spiral groove 101 to the second internal space 66 can effectively move to the discharge port 69 through the adjacent junction 72. Therefore, the debris is less likely to remain in the second internal space 66, and flows smoothly to be discharged from the discharge port 69 to the outside.

[0046] In addition, a hollow central passage P is formed at the center of the connection part 100, surrounding the central axis X. Therefore, the debris flowing through the suction lumen 21 can smoothly enter the spiral groove 101 of the connection part 100. As a result, the debris is less likely to clog the spiral groove 101, and flows smoothly and is discharged to the outside from the discharge port 69. The discharged debris reaches the pump 232 through the suction tube 231. The debris that reaches the pump 232 is discharged to the waste liquid pack 235 as shown in FIG. 1. After the cutting of the lesion and the suction of the debris are completed, the surgeon stops the operation of the driving device 200. This stops the rotation of the driving shaft 20 and stops the suction of the pump 232. This stops the cutting by the cutting part 40 and the discharge of the debris. After this, the medical device 10 is removed from the blood vessel, and the treatment is completed.

[0047] As described above, the medical device 10 according to the first embodiment is a medical device 10 for removing objects from a biological lumen, and includes a rotatable drive shaft 20 having an inner cavity, a cutting section 40 fixed to a distal portion of the drive shaft 20 for cutting objects, a proximal shaft 90 arranged proximal to the drive shaft 20 and rotatable, a connection section 100 connecting the proximal shaft 90 and the drive shaft 20 and capable of transmitting the rotational force of the proximal shaft to the drive shaft 20, and a housing 60 rotatably housing the connection section 100 and having an exhaust port 69 formed therein for exhausting the cut object to the outside, the drive shaft 20 having a proximal opening 25 at a proximal end surface 27 that opens in the axial direction (direction along the central axis X) and discharges the cut object, and the cross-sectional shape of the connection section 100 at the plane where the proximal end surface 27 is located is different from the shape of the proximal end surface 27. At least a portion of the object discharged from the proximal opening 25 is discharged directly into the internal space of the housing 100 while moving in the axial direction, without passing through the inside of the connection portion 100 .

[0048] In the medical device 10 configured as described above, debris, which is an object formed by cutting with the cutting unit 40 and flows proximally through the inner cavity of the drive shaft 20, is discharged through the proximal opening 25 that opens in the axial direction, and is therefore unlikely to wrap around the rotating connection unit 100. In particular, when the proximal opening (discharge port) of the drive shaft, which is a tubular body, is a side hole penetrating the side wall surface of the tubular body, the debris discharged from the side hole is likely to wrap around the rotating drive shaft. Compared to this case, the medical device 10 can significantly reduce the wrapping of debris. Therefore, even if debris wraps around the connection unit 100, the debris wrapped around due to rotation is unlikely to block the proximal opening 25 that opens in the axial direction. In other words, the proximal opening 25 that opens in the axial direction is likely to form a gap in the axial direction even if debris wraps around it, so that the proximal opening of the drive shaft 20 is prevented from being completely blocked by debris. Therefore, the medical device 10 can suck up debris formed by cutting the lesion, suppress the debris from accumulating in the device, and effectively discharge the debris. In addition, since the connecting part 100 has a shape different from that of the proximal part of the drive shaft 20, it is easy to make the shape of the connecting part 100 not hinder the release of debris from the proximal opening 25 while connecting the proximal shaft 90 and the drive shaft 20. In other words, the connecting part 100 can be freely designed without depending on the shape of the drive shaft 20, and therefore can be made into a shape suitable for the release of debris from the proximal opening 25.

[0049] Furthermore, the connection part 100 is not cylindrical as a whole. Therefore, even when the connection part 100 is connected to the drive shaft 20, which has a cylindrical shape and has a proximal opening 25, the proximal opening 25 is likely to maintain a state in which it is open in the axial direction. Since the connection part 100 does not form an internal space surrounded by a cylindrical shape, an object released in the axial direction from the proximal opening 25 is likely to be released directly into the internal space of the housing 100 without entering the internal space of the connection part 100.

[0050] Furthermore, the connecting part 100 abuts against the proximal end surface 27 of the drive shaft 20. This allows the connecting part 100 to be connected to the drive shaft 20 without entering the inner cavity of the drive shaft 20. This allows the inner cavity of the drive shaft 20 to be wide. This makes it easier for debris to be efficiently discharged from the inner cavity of the drive shaft 20. Note that in the case where the drive shaft 20 does not have the auxiliary member 23, the proximal end surface of the drive shaft 20 may be the proximal end surface 28 of the drive shaft body 22.

[0051] Moreover, the connection part 100 has a spiral groove 101 extending in a spiral shape on the outer circumferential surface. As a result, the spiral groove 101 of the rotating connection part 100 applies a force toward the proximal side to the debris inside, thereby assisting the movement of the debris to the proximal side. As a result, the debris moves along the spiral groove 101, and is urged to be discharged by receiving a force from the spiral groove 101. Therefore, the debris is less likely to be wound around the rotating connection part 100. Therefore, the medical device 10 can suppress the retention of debris in the proximal opening 25 by the spiral groove 101, and can effectively discharge the debris. The connection part 100 having the spiral groove 101 extending in a spiral shape on the outer circumferential surface may be formed, for example, by twisting a substantially plate-shaped member.

[0052] Also, there is one spiral groove 101, and the depth H of the spiral groove 101 in the direction from the outer circumferential surface of the connection part 100 toward the central axis X of the connection part 100 may exceed the distance R from the outer circumferential surface of the connection part 100 to the central axis X. As a result, unlike the case where there are two or more spiral grooves 101, the connection part 100 has a hollow central passage P that extends linearly along the central axis X. Therefore, the connection part 100 can secure a wide flow path continuing from the inner cavity of the drive shaft 20 while assisting the movement of debris toward the proximal side by the spiral groove 101. Therefore, the debris can flow smoothly through the spiral groove 101 of the connection part 100 without clogging. Therefore, the debris is easily discharged well from the inner cavity of the drive shaft 20 and the spiral groove 101 of the connection part 100.

[0053] The drive shaft 20 also has a drive shaft body 22 extending proximally from the cutting portion 40, and a tubular auxiliary member 23 surrounding the outer circumferential surface of the proximal portion of the drive shaft body 22 and the distal portion of the connection portion 100. This improves the fixing force of the connection portion 100 to the drive shaft body 22. The auxiliary member 23 is also disposed so as to surround the drive shaft body 22 and the connection portion 100, so that a wide flow path through which the debris flows can be secured. This makes it easier for the debris to be released from the lumen of the drive shaft 20.

[0054] Furthermore, a part of the connection part 100 is inserted inside the drive shaft 20, and in an axially orthogonal cross section (cross section perpendicular to the central axis X) at the site where the connection part 100 of the drive shaft 20 is inserted, the flow path area of ​​the drive shaft 20 is equal to or larger than the area occupied by the connection part 100. This makes it difficult for the movement of debris flowing through the inner cavity of the drive shaft 20 to be hindered by the connection part 100 disposed inside the drive shaft 20. Therefore, the debris is less likely to accumulate in the suction lumen 21, and is easily discharged. The flow path area of ​​the drive shaft 20 may be smaller than the area occupied by the connection part 100.

[0055] <Second embodiment> 5, the medical device 10 according to the second embodiment differs from the first embodiment only in the structure of the connection part 120. Note that parts having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0056] The connecting part 120 has two spiral grooves 121 and 122. Therefore, the part of the connecting part 120 where the spiral grooves 121 and 122 are formed has a twisted plate shape. The distal part of the connecting part 120 arranged inside the auxiliary member 23 has a protruding part 123 whose outer diameter gradually decreases toward the distal side on the central axis X of the connecting part 120. That is, the connecting part 120 has, at the distal part, the protruding part 123 that protrudes toward the distal side and becomes thinner. As a result, the material constituting the connecting part 120 decreases toward the distal side, and inevitably, a wide passage through which the debris can pass is secured. Therefore, the debris flowing toward the proximal side through the inner cavity of the drive shaft 20 easily passes through the protruding part 123. Therefore, the debris is less likely to wind around the rotating protruding part 123. Therefore, the medical device 10 can suppress the retention of the debris formed by cutting the lesion and effectively discharge the debris. It should be noted that the distal end of protrusion 123 may or may not enter suction lumen 21 of drive shaft 20 .

[0057] In addition, the distal portion of connection part 120 is generally plate-shaped, and both surfaces (bottom surfaces of spiral grooves 121, 122) arranged in the plate thickness direction of connection part 120 are arranged along the central axis X of drive shaft 20. As a result, debris flowing through the inner cavity of drive shaft 20 toward the proximal side flows along the surface of connecting part 120, which is a rotating plate, and is therefore unlikely to wrap around connecting part 120.

[0058] <Third embodiment> As shown in Fig. 6, the medical device 10 according to the third embodiment differs from the first embodiment only in the structure of the connection part 130. Note that parts having the same functions as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0059] The connecting part 130 has two spiral grooves 131 and 132, as in the second embodiment. The distal part of the connecting part 130 disposed inside the auxiliary member 23 has a recess 133 recessed toward the proximal side. The connecting part 130 has a recess 133 recessed toward the proximal side on the central axis X of the connecting part 130. As a result, the material constituting the connecting part 130 decreases toward the distal side, and a passage through which the debris can pass is inevitably secured widely. Therefore, the debris flowing toward the proximal side through the inner cavity of the drive shaft 20 easily passes through the recess 133. Therefore, the debris is less likely to be wound around the rotating recess 133. Therefore, the medical device 10 can suppress the retention of the debris formed by cutting the lesion and effectively discharge the debris. The most distal end of the connecting part 130 may contact the proximal end surface 28 of the drive shaft body 22, but it is not necessary for the contact to be made.

[0060] 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 concept of the present invention. For example, the biological lumen into which the medical device 10 is inserted is not limited to a blood vessel, and may be, for example, a vascular tract, a ureter, a bile duct, an oviduct, a hepatic duct, or the like. The medical device 10 and the driving device 200 may be integrally configured. As in the modified example shown in FIG. 7, the connecting portion 140 may be a flat plate. As in the modified example shown in FIG. 8, the connecting portion 150 may be a member whose cross section perpendicular to the axis is shaped like a cross. That is, the connecting portion 150 has a plurality of flat plate shapes.

[0061] The connecting part may be a member formed of one or more wires wound in a spiral shape into a cylindrical shape. The wires may be solid or hollow. The cutting part may not be provided. And the object moving on the drive shaft may be cut by the rotation of the connecting part.

[0062] Also, the suction force may be generated by the drive shaft or the connection part, instead of the suction part 230 connected to the discharge port 69. If the drive shaft and / or the connection part have the structure of an archimedes screw pump, the suction force can be generated by rotating. In this case, the discharge port 69 can discharge the debris even if it is not connected to the suction part 230 that generates the suction force.

[0063] This application is based on Japanese Patent Application No. 2019-160859 filed on September 4, 2019, the disclosures of which are hereby incorporated by reference in their entirety. [Explanation of symbols]

[0064] 10 Medical Devices 20 Drive shaft 21 Suction lumen 22 Drive shaft body 23 Auxiliary Materials 25 Proximal opening 26 Distal opening 27 Proximal end face of drive shaft 40 Cutting part 60 Housing 69 Exhaust port 72 Junction 90 Base end shaft 100, 120, 130 Connection 101, 121, 122, 131, 132 spiral groove 123 Protrusion S range X center axis

Claims

1. 1. A medical device for removing an object from a biological lumen, comprising: a rotatable drive shaft having an internal bore; a cutting portion fixed to a distal portion of the drive shaft for cutting an object; a rotatable proximal shaft disposed proximally of the drive shaft; a connection portion that connects the proximal shaft and the drive shaft and is capable of transmitting a rotational force of the proximal shaft to the drive shaft; a housing that rotatably accommodates the connecting portion and has a discharge port formed therein for discharging the cut object to the outside, A medical device, wherein the connector has a helical shaped portion and a central passageway surrounded by the helical shaped portion and in communication with an inner lumen of the drive shaft.

2. The medical device of claim 1, wherein the connection portion has a spiral groove extending spirally on its outer peripheral surface, and the depth of the spiral groove in a direction from the outer peripheral surface of the connection portion toward the central axis of the connection portion exceeds the distance from the outer peripheral surface of the connection portion to the central axis.

3. The medical device according to claim 1 or 2, wherein the direction in which the spiral-shaped portion winds toward the distal side when viewed from the proximal side corresponds to the direction of rotation of the connecting portion.

4. The medical device according to any one of claims 1 to 3, wherein a proximal end of the spiral-shaped portion formed in the connecting portion is located distal to the proximal end of the connecting portion.

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