Rail-based atherectomy system with abrasive elements

Abstract

A rail-based atherectomy system includes a hand-held driver having a motor. An elongated flexible drive shaft has a proximal end portion and a distal end portion. The proximal end portion is drivingly coupled to the motor. The distal end portion defines an axis of rotation. An abrasive element is fixedly disposed on the distal end portion of the elongated flexible drive shaft. The abrasive element includes a first flat side, a second flat side, a front tapered end portion having a front end, and a rear tapered end portion having a rear end. The first flat side and the second flat side are on opposite sides of the axis of rotation.

Description

[0001] Cross-references to related applications

[0002] none. Technical Field

[0003] This invention relates to an atherectomy system, and more specifically, to an orbital atherectomy system with abrasive elements. Background Technology

[0004] Coronary artery disease can be caused, for example, by atherosclerosis. Atherosclerosis occurs when fat, cholesterol, and / or other substances build up in the walls of blood vessels, forming hard structures called occlusions, such as plaques and / or atherosclerotic (stenotic) lesions. Over time, these occlusions may increase in size, causing the blood vessels to become essentially blocked and / or completely blocked, resulting in chronic total occlusion (CTO).

[0005] Rotational atherectomy is a technique used to grind up, for example, calcified arterial lesions. Rotational atherectomy devices and rotational atherectomy procedures can also be referred to as rotational angioplasty devices and / or rotational angioplasty procedures. One type of rotational atherectomy device is known as a track-type atherectomy device, such as the Diamondback offered by Cardiovascular Systems, Inc. (“CSI”). Peripheral orbital atherosclerotic plaque removal device.

[0006] Rotary atherosclerotic plaque resection devices may include abrasive elements attached to a rotatable, elongated, flexible drive shaft. The abrasive element may be referred to as a bristle, crown, and / or bead. The rotatable, elongated, flexible drive shaft can be delivered to the desired location on a guidewire and / or through a sheath. The drive shaft can rotate at high speeds (e.g., between 20,000 and 160,000 rpm). As the abrasive element rotates, it can be advanced over a narrowed lesion, causing the abrasive element to contact the occluded plaque. In this way, the abrasive element engages the diseased lesion surface and grinds the plaque into very small particles. These small particles can be absorbed by the body or captured using an embolization protection device.

[0007] There is a need in the art for an atherosclerotic plaque resection system with an abrasive element that can better engage occluders with small initial pore sizes, such as occluders with an initial opening through which only a guidewire can pass. Summary of the Invention

[0008] The present invention provides an atherosclerotic plaque resection system with an abrasive element capable of engaging occluders with a small initial aperture, such as occluders with an initial opening through which only a guidewire can pass.

[0009] In one embodiment, the invention relates to a track-type atherosclerotic plaque resection system comprising a handheld actuator with a motor. An elongated flexible drive shaft has a proximal portion and a distal portion. The proximal portion is drivably coupled to the motor. The distal portion defines an axis of rotation. An abrasive element is fixedly disposed on the distal portion of the elongated flexible drive shaft. The abrasive element includes a first flat side, a second flat side, a front tapered end portion having a front end, and a rear tapered end portion having a rear end. The first flat side and the second flat side are located on opposite sides of the axis of rotation.

[0010] In another embodiment, the invention relates to a track device comprising an elongated flexible drive shaft and a grinding element. The elongated flexible drive shaft has a proximal portion and a distal portion. The proximal portion is configured to be drivably coupled to a motor. The distal portion defines an axis of rotation. The grinding element is fixedly disposed on the distal portion of the elongated flexible drive shaft. The grinding element includes a first flat side, a second flat side, a front tapered end portion having a front end, and a rear tapered end portion having a rear end. The first flat side and the second flat side are located on opposite sides of the axis of rotation.

[0011] In another form, the invention relates to an abrasive element for use in a track-type atherosclerotic plaque resection system. The abrasive element, for example, a body, includes a rotation axis, a first flat side, a second flat side, a front tapering portion having a front end, and a rear tapering portion having a rear end, wherein the first flat side and the second flat side are located on opposite sides of the rotation axis.

[0012] One advantage of this invention is that the flat sides of the grinding element are designed to have lower mass and less front surface area contact during grinding, while maintaining the same overall cross-sectional diameter. The lower mass and smaller contact area of ​​the grinding element help reduce the power required by the motor to bring the system to full speed.

[0013] Another advantage of the invention is that, when the grinding element rotates at high speed, it follows an orbital motion path rather than a concentric motion. In at least some embodiments, the orbital motion is characterized by a cantilever and is enhanced by the non-uniform mass distribution of the grinding element with its flat sides.

[0014] Another advantage is that, due to the track motion, the track device (i.e., the slender, flexible drive shaft and the grinding element) creates a cavity in the occlusion with a diameter larger than the outer diameter of the grinding element.

[0015] Another advantage is that the track device of the present invention provides a smooth response for the user during activation and propulsion through obstructions.

[0016] Another advantage of the grinding element embodiment provided by the present invention is that the grinding element can have an intermediate section between two tapered portions, wherein the length of the intermediate section can be changed or eliminated as desired to optimize the weight and balance of the track device.

[0017] In embodiments where the grinding element is mounted on the distal end of a slender, flexible drive shaft, another advantage over existing track-type atherosclerotic plaque resection devices is that this design is better able to engage occlusions with small initial lumens or complete occlusions, requiring only the guidewire to partially pass through the occlusion. Attached Figure Description

[0018] The above and other features and advantages of the present invention, as well as the ways of implementing these features and advantages, will become more apparent from the following description of embodiments of the present invention taken in conjunction with the accompanying drawings, and the present invention will be better understood, wherein:

[0019] Figure 1 This is a schematic perspective view of an embodiment of a track-type atherosclerotic plaque removal system configured according to one aspect of the invention, having a handheld driver coupled to a track device having an elongated flexible drive shaft and abrasive elements.

[0020] Figure 2 Is Figure 1 The circle cut off at point 2-2 Figure 1 An enlarged perspective view of a portion of the track device, showing a grinding element coupled to the distal portion of an elongated flexible drive shaft according to an embodiment of the invention, wherein the grinding element is proximal to the distal end of the elongated flexible drive shaft.

[0021] Figure 3 yes Figure 1 and Figure 2 Side view of the grinding element.

[0022] Figure 4 yes Figure 1-3 End view of the grinding element.

[0023] Figure 5 It shows that it is applicable to and Figure 1 An enlarged side view of another embodiment of the track device used with a handheld driver, wherein the distal end of the elongated flexible drive shaft terminates at or near the front end of the grinding element.

[0024] Figure 6 yes Figure 5 End view of the track device.

[0025] Figure 7This is a side view of another embodiment of the grinding element, which can replace... Figure 1-6 The grinding element in any embodiment.

[0026] Figure 8 yes Figure 7 End view of the grinding element.

[0027] Figure 9 yes Figure 5 A variant of the track device embodiment, wherein the distal end of the grinding element has a rounded front end.

[0028] Figure 10 yes Figure 9 End view of the track device.

[0029] Figure 11 yes Figure 9 and Figure 10 A variant of the track device embodiment, wherein the grinding element is longitudinally asymmetrical.

[0030] Figure 12 yes Figure 11 End view of the track device.

[0031] In several views, corresponding reference numerals denote corresponding parts. The examples listed herein illustrate embodiments of the invention, and such examples should not be construed as limiting the scope of the invention in any way. Detailed Implementation

[0032] Now refer to the attached diagram, and more specifically to... Figure 1 and Figure 2 The image shows a track-type atherosclerotic plaque removal system 10 according to an embodiment of the present invention.

[0033] The track-type atherosclerotic plaque resection system 10 includes a handheld actuator 12 configured to rotate a track assembly 14 at high speeds (e.g., 20,000–160,000 rpm). The track assembly 14 includes an elongated flexible drive shaft 16 and an abrasive element 18. The elongated flexible drive shaft 16 is flexible enough to adapt to the curvature of the vascular system. The abrasive element 18 is disposed on and fixedly (i.e., non-removably or non-detachably) attached to the elongated flexible drive shaft 16. In this embodiment, the track assembly 14 allows a guidewire 20 to pass axially through and rotate about the guidewire. Those skilled in the art will recognize that lubricant or saline solution can be supplied through the elongated flexible drive shaft 16 to cool / lubricate the coil shaft / guidewire interface, as is known in the art. With the grinding element 18 in contact with the occlusion, the high-speed rotation of the track device 14 grinds (e.g., abrades) the occlusion, such as calcified plaques and / or atherosclerotic (stenotic) lesions in a blood vessel, to reduce at least a portion of the occlusion to small particles. When the grinding element 18 rotates at high speed, it follows an orbital motion path rather than a concentric motion.

[0034] The handheld driver 12 may include a motor 22, such as a direct current (DC) motor, motor controller circuitry 24, and a user interface 26. An internal battery power supply 28 is electrically connected to the motor 22, motor controller circuitry 24, and user interface 26. Electrical power can be supplied to the motor 22, motor controller circuitry 24, and user interface 26 via the internal battery power supply 28. In this embodiment, the internal battery power supply 28 includes a rechargeable or replaceable battery 28-1. Alternatively, a non-internal power source, such as an AC wall socket, may supply electrical power to the handheld driver 12.

[0035] User interface 26 may be, for example, a touchscreen or panel with physical or virtual buttons, for providing user input commands to motor controller circuit 24. Motor controller circuit 24 includes processing circuitry and power circuitry to receive user input commands, execute program instructions, and provide power and operating signals to motor 22. Such user input commands may include, for example, selectable speed commands, motor acceleration and / or torque distribution commands, and / or rotation direction commands.

[0036] The track assembly 14, including an elongated flexible drive shaft 16 and a grinding element 18, is configured to extend into a patient's blood vessel, such as an artery. In this embodiment, the elongated flexible drive shaft 16 may be, for example, an elongated, tightly wound metal coil. Alternatively, the elongated flexible drive shaft 16 may be a flexible metal or polymer tube. The elongated flexible drive shaft 16 includes a proximal portion 16-1, a distal portion 16-2, a distal end 16-3, and an elongated lumen 16-4, such as an elongated guidewire lumen. The distal end 16-3 is the distal terminus of the distal portion 16-2 of the elongated flexible drive shaft 16.

[0037] The proximal portion 16-1 of the elongated flexible drive shaft 16 is, for example, directly or indirectly drivably connected via a gear train, i.e., connected to the rotatable motor shaft 22-1 of the motor 22. In this embodiment, the distal portion 16-2 may constitute, for example, 0.5% to 10% of the total length of the elongated flexible drive shaft 16. The distal portion 16-2 of the elongated flexible drive shaft 16 defines a rotation axis 30 about which the grinding element 18 rotates in conjunction with the elongated flexible drive shaft 16.

[0038] The elongated lumen 16-4 is configured, for example, in size and shape to accommodate the guidewire 20. The elongated lumen 16-4 is configured to slidably receive the guidewire 20 such that an elongated flexible drive shaft 16 carrying the abrasive element 18 can be axially advanced on and rotated about the guidewire 20 and the axis of rotation 30. In this embodiment, the distal portion 16-2 of the elongated flexible drive shaft 16 and the abrasive element 18 can be longitudinally advanced on the guidewire 20 and into the patient's blood vessel to engage occlusions in the vessel. Alternatively, in some embodiments, a track-type atherosclerotic plaque resection system 10 can be used without the guidewire 20, wherein, for example, a sheath (not shown) can be used to introduce the track device 14 into the patient's blood vessel.

[0039] Also refer to Figure 3 and Figure 4 The image shows a side view and an end view of the grinding element 18 separately. The grinding element 18 of the track assembly 14 is fixedly disposed on (i.e. disposed thereon and fixedly attached thereto) the distal portion 16-2 of the elongated flexible drive shaft 16. This fixed attachment of the grinding element 18 to the distal portion 16-2 of the elongated flexible drive shaft 16 can be achieved, for example, by welding or by adhesive.

[0040] exist Figure 1 and Figure 2 In one embodiment, the grinding element 18 is coupled to a location on the distal portion 16-2 of the elongated flexible drive shaft 16, proximal to the distal end 16-3 of the elongated flexible drive shaft 16. Figure 1 and Figure 2In one embodiment, the grinding element 18 may be coupled to the elongated flexible drive shaft 16, for example, at a position ranging from 8 mm to 25 mm proximal to the distal end 16-3 of the elongated flexible drive shaft 16.

[0041] exist Figure 1-6 In each of the embodiments shown, the abrasive element 18 is configured to be symmetrical about a rotation axis 30, configured to have a non-uniform mass distribution about the rotation axis 30, and / or configured to have a center of mass located on the rotation axis 30. According to one aspect of the invention, in this embodiment, the abrasive element 18 includes a first flat side 32, a second flat side 34, a front tapered end portion 36 having a front end 36-1, a rear tapered end portion 38 having a rear end 38-1, an intermediate section 40 between the front tapered end portion 36 and the rear tapered end portion 38, and an elongated opening 42. As used herein, the term "flat side" refers to a plane, which may include surface irregularities such as noticeable bumps, pits, or ridges, or alternatively may be smooth.

[0042] The elongated opening 42 of the grinding element 18 is configured, for example, in size and shape to receive at least a portion of the elongated flexible drive shaft 16. The grinding element 18 is fixedly attached to the distal portion 16-2 of the elongated flexible drive shaft 16 at the elongated opening 42, for example, by welding or by adhesive.

[0043] The abrasive element 18 has an outer surface 18-1 comprising a first flat side 32, a second flat side 34, a front tapered end portion 36, a rear tapered end portion 38, and an intermediate section 40, wherein at least a portion of the outer surface 18-1 is roughened, for example, by including abrasive particles 44 (indicated by dots in the figures). In this embodiment, each of the first flat side 32, the second flat side 34, the front tapered end portion 36, the rear tapered end portion 38, and the intermediate section 40 may include abrasive particles 44. However, in some applications, it may be desirable that some portions of the outer surface 18-1, such as the first flat side 32 and the second flat side 34, may be without abrasive particles 44. As a further alternative, in some applications, it may be desirable that the first flat side 32 and the second flat side 34 have a reduced or increased amount of abrasive particles 44 compared to the rest of the abrasive element 18.

[0044] The abrasive particles 44 may be, for example, diamond particles present in an adhesive abrasive coating applied to form an outer surface 18-1 on a body substrate (e.g., a metal or polymer body) defined by a first flat side 32, a second flat side 34, a front tapered end portion 36, a rear tapered end portion 38, and an intermediate section 40. Alternatively, the abrasive element 18 may be formed of a compressed or bonded material having abrasive particles 44 exposed at the outer surface 18-1.

[0045] The first flat side 32 and the second flat side 34 are located on opposite sides of the rotation axis 30 and face each other, that is, the first flat side 32 and the second flat side 34 face opposite directions. The intermediate section 40 has convex side surfaces 40-1 and 40-2 that are diametrically opposed at a diameter of 40-3, and these convex side surfaces are circumferentially located between the first flat side 32 and the second flat side 34 that face each other.

[0046] The first flat side 32 and the second flat side 34 can be substantially parallel, and in this embodiment, the first flat side 32 and the second flat side 34 are parallel. As used herein, the term "substantially parallel" means including parallelism and a range of permissible variations from parallelism to plus or minus three degrees. Specifically, refer to... Figure 3 and Figure 4 The longitudinal length 46 of each of the first flat side 32 and the second flat side 34 is less than the total longitudinal length 48 of the grinding element 18. The total longitudinal length 48 of the grinding element 18 may be, for example, between approximately 1 mm and 15 mm. In one embodiment, for example, the total longitudinal length 48 of the grinding element 18 may be 8 mm.

[0047] In this embodiment, the front tapered portion 36 and the rear tapered portion 38 of the abrasive element 18 taper in opposite directions along the axis of rotation 30. Furthermore, the front tapered portion 36 and the rear tapered portion 38 of the abrasive element 18 may be axially (longitudinally) symmetrical, for example, symmetrical with respect to a plane orthogonal to the axis of rotation 30. In this embodiment, each of the front tapered portion 36 and the rear tapered portion 38 of the abrasive element 18 is at least partially defined by a tapered surface, wherein each tapered surface abuts and transitions to a first flat side 32 and a second flat side 34. The forward-facing front tapered portion 36 allows access into a reduced-diameter opening in an occlusion of the blood vessel (e.g., a stenotic lesion or plaque), for example, where the opening only needs to be substantially large enough to accommodate the diameter of the guidewire 20. The rearward-facing rear tapered portion 38 of the abrasive element 18 allows for the application of a lower withdrawal force during the retraction of the track device 14 during the procedure.

[0048] Reference Figure 3 The taper angle 50 of the front tapered end portion 36 of the grinding element 18 relative to the rotation axis 30 can be, for example, in the range of 10 degrees to 75 degrees, and the taper angle 52 of the rear tapered end portion 38 of the grinding element 18 relative to the rotation axis 30 can be, for example, in the range of -10 degrees to -75 degrees. Therefore, referring to... Figure 4 The diameter 53 of each of the front tapered end portion 36 at the front end 36-1 and the rear tapered end portion 38 at the rear end 38-1 is smaller than the diameter 40-3 of the middle section 40.

[0049] exist Figure 1 and Figure 2 In the embodiments shown, reference is also made to Figure 3 and Figure 4 The tapered end portion 36 of the abrasive element 18 terminates proximally to the distal end 16-3 of the elongated flexible drive shaft 16. In other words, a sub-portion 16-5 of the distal end portion 16-2 of the elongated flexible drive shaft 16 extends distally from the front end 36-1 of the tapered end portion 36 of the abrasive element 18. When the abrasive element 18 rotates at high speed, it undergoes an orbital motion path rather than a concentric motion, which is enhanced by the non-uniform mass distribution of the abrasive element 18 resulting from the presence of a first flat side 32 and a second flat side 34. The orbital motion of the abrasive element 18 creates an opening in the occlusion of the blood vessel, which is larger than the maximum diameter of the abrasive element 18 itself, for example, a diameter of 40-3.

[0050] Figure 5 and Figure 6 Another embodiment utilizing an elongated flexible drive shaft 16 and a grinding element 18 is shown, which together form an alternative track device 54. The track device 54 can replace... Figure 1 and Figure 2 The track device 14.

[0051] exist Figure 5 and Figure 6 In the illustrated track device 54, the distal end 16-3 of the elongated flexible drive shaft 16 terminates at or near the front end 36-1 of the tapered front portion 36 of the grinding element 18. As the grinding element 18 rotates, it follows a track motion path rather than a concentric motion. The track motion of the grinding element 18 on the elongated flexible drive shaft 16 configured as the track device 54 is characterized by cantilevering, which is reinforced by the non-uniform mass distribution of the grinding element 18 caused by the first flat side 32 and the second flat side 34.

[0052] The insertion depth 56 of the elongated flexible drive shaft 16 into the abrasive element 18, measured from the rear end 38-1, can vary during assembly to manipulate the amplitude of the orbital movement of the abrasive element 18, wherein a smaller insertion depth 56 results in a larger amplitude of orbital movement. The orbital movement of the abrasive element 18 creates an opening in the occlusion that is larger than the maximum diameter of the abrasive element 18 itself, for example, a diameter of 40-3.

[0053] Figure 7 and Figure 8 Another embodiment of the configuration for the grinding element 58 is shown, which can replace the grinding element with... Figure 1-6 The grinding element 18 in any of the foregoing embodiments. The main difference between the overall structure of the grinding element 58 and the overall structure of the grinding element 18 is that the grinding element 18 omits the intermediate section 40 (e.g., compared to...). Figure 3 and Figure 5 ).exist Figure 7 and Figure 8 In the embodiment shown, the grinding element 58 is configured to be symmetrical about the rotation axis 30, configured to have a non-uniform mass distribution about the rotation axis 30, and / or configured to have a centroid located on the rotation axis 30.

[0054] exist Figure 7 and Figure 8 In one embodiment, the polishing element 58 includes a first flat side 62, a second flat side 64, a front tapered end portion 66 having a front end 66-1, a rear tapered end portion 68 having a rear end 68-1, and an elongated opening 70. The front tapered end portion 66 of the polishing element 58 transitions directly into the rear tapered end portion 68 of the polishing element 58 to form a crown apex 72 with curvatures 72-1, 72-2 opposite to the diameter at a diameter 72-3, for example at the longitudinal midpoint of the polishing element 58.

[0055] The elongated opening 70 of the grinding element 58 is configured in size and shape, for example, to receive at least a portion of, for example, an elongated flexible drive shaft 16. The grinding element 58 may be fixedly attached to the distal portion 16-2 of the elongated flexible drive shaft 16 at the elongated opening 70, for example, by welding or by adhesive.

[0056] The abrasive element 58 has an outer surface 58-1 comprising a first flat side 62, a second flat side 64, a front tapered end portion 66, and a rear tapered end portion 68, wherein at least a portion of the outer surface 58-2 is roughened, for example, by including abrasive particles 44 (indicated by dots in the figures). In this embodiment, each of the first flat side 62, the second flat side 64, the front tapered end portion 66, and the rear tapered end portion 68 may include abrasive particles 44. However, in some applications, it may be desirable that some portions of the outer surface 58-1, such as the first flat side 62 and the second flat side 64, may be free of abrasive particles 44. As a further alternative, in some applications, it may be desirable that the first flat side 62 and the second flat side 64 have a reduced or increased amount of abrasive particles 44 compared to the rest of the abrasive element 18.

[0057] The abrasive particles 44 may be, for example, diamond particles present in an adhesive abrasive coating applied to form an outer surface 58-1 on a body substrate (e.g., a metal or polymer body) defined by a first flat side 62, a second flat side 64, a front tapered end portion 66, and a rear tapered end portion 68. Alternatively, the abrasive element 58 may be formed of a compressed material having abrasive particles 44 exposed at the outer surface 58-1.

[0058] The first flat side 62 and the second flat side 64 are located on opposite sides of the rotation axis 30 and face each other, that is, the first flat side 62 and the second flat side 64 face opposite directions. The diameter-relative curvatures 72-1 and 72-2 of the crown apex 72 are located circumferentially between the opposing first flat side 62 and the second flat side 64.

[0059] The first flat side 62 and the second flat side 64 can be substantially parallel, and in this embodiment, the first flat side 62 and the second flat side 64 are parallel. Specifically, referring to... Figure 7 and Figure 8 The longitudinal length 74 of each of the first flat side 62 and the second flat side 64 is less than the total longitudinal length 76 of the grinding element 58. The total longitudinal length 76 of the grinding element 58 may be, for example, between approximately 1 mm and 15 mm. In one embodiment, for example, the total longitudinal length 76 of the grinding element 58 may be 8 mm.

[0060] In this embodiment, the anterior tapered portion 66 and the posterior tapered portion 68 of the abrasive element 58 taper in opposite directions along the axis of rotation 30. Furthermore, the anterior tapered portion 66 and the posterior tapered portion 68 of the abrasive element 58 may be axially symmetrical. In this embodiment, each of the anterior tapered portion 66 and the posterior tapered portion 68 of the abrasive element 58 is at least partially defined by a tapered surface, wherein each tapered surface abuts and transitions to a first flat side 62 and a second flat side 64. The forward-facing anterior tapered portion 66 allows access into a reduced-diameter opening in an occlusion of the blood vessel (e.g., a stenotic lesion or plaque), for example, where the opening only needs to be substantially large enough to accommodate the diameter of the guidewire 20 (see also...). Figure 1 and Figure 2 (For reference only). The rearward-facing tapered end portion 68 of the grinding element 58 allows for the application of a lower retraction force during the retraction of the track device during the procedure.

[0061] Reference Figure 7 The taper angle 78 of the front tapered end portion 66 of the grinding element 58 relative to the rotation axis 30 can be, for example, in the range of 10 degrees to 75 degrees, and the taper angle 80 of the rear tapered end portion 68 of the grinding element 58 relative to the rotation axis 30 can be, for example, in the range of -10 degrees to -75 degrees. Therefore, the diameter 82 of each of the front tapered end portion 66 at the front end 66-1 and the rear tapered end portion 68 at the rear end 68-1 is smaller than the diameter 72-3 of the crown apex 72.

[0062] Figure 9 and Figure 10An embodiment utilizing an elongated flexible drive shaft 16 and a grinding element 118 is shown, which together form an alternative track device 154. The track device 154 can replace... Figure 1 and Figure 2 Track device 14. Track device 154 is Figure 5 and Figure 6 A variant of the orbital device 54.

[0063] For example, in grinding element 18 (see, for example, see...) Figure 1-6 As in the embodiment described above, the abrasive element 118 includes a first flat side 32, a second flat side 34, a rear tapered end portion 38 having a rear end 38-1, an intermediate section 40, and an elongated opening 42. However, the abrasive element 118 also includes a front tapered end portion 136 having a rounded front end 136-1 and a guide wire opening 136-2 located on the rotation axis 30. The intermediate section 40 is located between the front tapered end portion 136 and the rear tapered end portion 38. The guide wire opening 136-2 is sized and shaped to slidably receive the guide wire 20.

[0064] In this embodiment, the tapered end portion 136 of the abrasive element 118 is at least partially defined by a tapered surface, which abuts and transitions to a first flat side 32 and a second flat side 34. The taper angle 150 of the tapered end portion 136 of the abrasive element 118 relative to the axis of rotation 30 can be, for example, in the range of 10 degrees to 75 degrees. The circular tip 136-1 has a circular, for example, hemispherical surface. The circular tip 136-1 can provide additional benefits when entering the occlusion through the circular surface, which opens a smooth transition from the guidewire 20 to the tapered surface of the tapered end portion 136.

[0065] The insertion depth 156 of the elongated flexible drive shaft 16, measured from the rear end 38-1, into the grinding element 118 can be varied during assembly to manipulate the amplitude of the orbital movement of the grinding element 118, wherein a smaller insertion depth 156 results in a larger amplitude of orbital movement. The orbital movement of the grinding element 118 creates an opening in the occlusion that is larger than the maximum diameter of the grinding element 118 itself, for example, a diameter of 40-3.

[0066] The orbital motion of the grinding element 118 on the elongated flexible drive shaft 16 configured as the track device 154 is characterized by cantilever, which is reinforced by the non-uniform mass distribution of the grinding element 118 caused by the first flat side 32 and the second flat side 34.

[0067] Figure 11 and Figure 12An embodiment utilizing an elongated flexible drive shaft 16 and a grinding element 218 is shown, which together form an alternative track device 254. The track device 254 can replace... Figure 1 and Figure 2 Track device 14. Track device 254 is Figure 9 and Figure 10 A variant of the orbital device 154.

[0068] In this embodiment, the grinding element 218 has a longitudinally asymmetrical configuration, including a first flat side 232, a second flat side 234, and a front tapered end portion 136 having a front end 136-1 (see also...). Figure 9 It has a rear end portion 238 with a rear end 238-1, an intermediate section 240 between the front tapered end portion 136 and the rear end portion 238, and an elongated opening 242.

[0069] The elongated opening 242 of the grinding element 218 is configured in size and shape, for example, to receive at least a portion of, for example, an elongated flexible drive shaft 16. The grinding element 218 is fixedly attached to the distal portion 16-2 of the elongated flexible drive shaft 16 at the elongated opening 242, for example, by welding or by adhesive.

[0070] The abrasive element 218 has an outer surface 218-1 comprising a first flat side 232, a second flat side 234, a front tapered end portion 136, a rear end portion 238, and an intermediate section 240, wherein at least a portion of the outer surface 218-1 is roughened, for example, by including abrasive particles 44 (indicated by dots in the figures). In this embodiment, each of the first flat side 232, the second flat side 234, the front tapered end portion 136, the rear end portion 238, and the intermediate section 240 may include abrasive particles 44. However, in some applications, it may be desirable that some portions of the outer surface 218-1, such as the first flat side 232 and the second flat side 234, may be without abrasive particles 44. As a further alternative, in some applications, it may be desirable that the first flat side 232 and the second flat side 234 have a reduced or increased amount of abrasive particles 44 compared to the rest of the abrasive element 218.

[0071] The abrasive particles 44 may be, for example, diamond particles present in an adhesive abrasive coating applied to form an outer surface 218-1 on a body substrate (e.g., a metal or polymer body) defined by a first flat side 232, a second flat side 234, a front tapered end portion 136, a rear end portion 238, and an intermediate section 240. Alternatively, the abrasive element 218 may be formed of a compressed or bonded material having abrasive particles 44 exposed at the outer surface 218-1.

[0072] The first flat side 232 and the second flat side 234 are located on opposite sides of the rotation axis 30 and face each other, that is, the first flat side 232 and the second flat side 234 face opposite directions and may be substantially the same. The intermediate section 240 has convex side surfaces 240-1 and 240-2 that are diametrically opposed at a diameter of 240-3, and these convex side surfaces are circumferentially located between the first flat side 232 and the second flat side 234 that face each other.

[0073] The first flat side 232 and the second flat side 234 may be substantially parallel, and in this embodiment, the first flat side 232 and the second flat side 234 are parallel. The longitudinal length of each of the first flat side 232 and the second flat side 234 is less than the total longitudinal length of the grinding element 218. The total longitudinal length of the grinding element 218 may be, for example, between approximately 1 mm and 15 mm. In one embodiment, for example, the total longitudinal length of the grinding element 218 may be 8 mm.

[0074] In this embodiment, the front tapered end portion 136 and the rear end portion 238 of the grinding element 218 face opposite directions along the rotation axis 30. Furthermore, the front tapered end portion 136 and the rear end portion 238 of the grinding element 218 are axially (longitudinally) asymmetrical.

[0075] In this embodiment, the tapered end portion 136 of the grinding element 218 is at least partially defined by a tapered surface, which abuts and transitions to a first flat side 232 and a second flat side 234. The taper angle 150 of the tapered end portion 136 of the grinding element 218 relative to the axis of rotation 30 can be, for example, in the range of 10 degrees to 75 degrees.

[0076] The rear end portion 238 of the abrasive element 218 has a circular, for example, hemispherical surface that abuts and transitions to the first flat side 232 and the second flat side 234. The forward-facing tapering end portion 136 allows access into a reduced-diameter opening in a vascular occlusion (e.g., a stenotic lesion or plaque), where the opening only needs to be substantially large enough to accommodate the diameter of the guidewire 20. The rearward-facing rear end portion 238 of the abrasive element 218 allows for the application of a lower retraction force during the retraction of the track device 254 during the procedure.

[0077] The insertion depth 256 of the elongated flexible drive shaft 16, measured from the rear end 238-1, into the grinding element 218 can be varied during assembly to manipulate the amplitude of the orbital movement of the grinding element 218, wherein a smaller insertion depth 256 results in a larger amplitude of orbital movement. The orbital movement of the grinding element 218 creates an opening in the occlusion that is larger than the maximum diameter of the grinding element 218 itself, for example, diameter 240-3.

[0078] The orbital motion of the grinding element 218 on the elongated flexible drive shaft 16 configured as the track device 254 is characterized by cantilever, which is reinforced by the non-uniform mass distribution of the grinding element 218 caused by the first flat side 232 and the second flat side 234.

[0079] The following items are also related to this invention:

[0080] In one embodiment, the present invention relates to a track-type atherosclerotic plaque resection system. The track-type atherosclerotic plaque resection system may include a handheld actuator, an elongated (flexible) drive shaft, and an abrasive element. The handheld actuator may have a motor. The elongated flexible drive shaft may have a proximal portion and a distal portion. The proximal portion may be drivably coupled to or configured to be drivably coupled to the motor. The distal portion defines a rotation axis. The abrasive element may be (fixedly) disposed on the distal portion of the elongated flexible drive shaft. The abrasive element may include a first flat side, a second flat side, a front tapered end portion having a front end, and a rear (tapered) end portion having a rear end. The first flat side and the second flat side are located on opposite sides of the rotation axis / on opposite circumferential sides of the abrasive element.

[0081] According to any embodiment, the abrasive element may have an outer surface including a first flat side, a second flat side, a front tapered end portion, and a rear (tapered) end portion. At least a portion of the outer surface includes abrasive particles.

[0082] According to any embodiment, the first flat side and the second flat side may be (substantially) parallel.

[0083] According to any embodiment, the longitudinal length of each of the first flat side and the second flat side may be less than the total longitudinal length of the grinding element.

[0084] According to some embodiments, the front tapering end portion and the rear (tapering) end portion of the grinding element taper in opposite directions along the axis of rotation.

[0085] According to the embodiment having a front tapered end portion and a rear tapered end portion, the cone angle of the front tapered end portion of the grinding element relative to the axis of rotation can be in the range of 10 degrees to 75 degrees, and the cone angle of the rear tapered end portion of the grinding element relative to the axis of rotation can be in the range of -10 degrees to -75 degrees.

[0086] According to any embodiment, the grinding element may be configured to be symmetrical about a rotation axis, configured to have a non-uniform mass distribution about a rotation axis, and configured to have a centroid located on the rotation axis.

[0087] According to any embodiment, the distal portion of the elongated flexible drive shaft includes the distal end of the elongated flexible drive shaft. According to some embodiments, the front tapered portion of the grinding element may terminate at a position proximal to the distal end of the elongated flexible drive shaft. Furthermore, according to other embodiments, a sub-portion of the distal portion of the elongated flexible drive shaft may extend distally from the front tapered portion of the grinding element.

[0088] According to some embodiments, the grinding element may include an intermediate section between a front tapered end portion and a rear (tapered) end portion. The intermediate section may have convex side surfaces that are diametrically opposed, the convex side surfaces being circumferentially located between a first flat side and a second flat side facing each other.

[0089] According to some embodiments, the front tapered portion of the grinding element may have a front end, the elongated flexible drive shaft may have a distal end at the distal end of the distal portion of the elongated flexible drive shaft, and the distal end of the elongated flexible drive shaft may terminate at or near the front end of the front tapered portion of the grinding element.

[0090] According to some embodiments, the front tapered end portion of the polishing element can directly transition into the rear (tapered) end portion of the polishing element.

[0091] According to an embodiment having a front tapered end portion and a rear tapered end portion, each of the front tapered end portion and the rear tapered end portion of the grinding element may be at least partially defined by a tapered surface. Each tapered surface may abut and transition to a first flat side and a second flat side.

[0092] According to any embodiment, the grinding element may include an elongated opening configured to receive an elongated flexible drive shaft. The grinding element may be securely attached to the distal portion of the elongated flexible drive shaft at the elongated opening by welding or by adhesive.

[0093] According to any embodiment, the embodiment may optionally include a guidewire, and wherein an elongated flexible drive shaft may have an elongated guidewire lumen configured to slidably receive the guidewire. The elongated flexible drive shaft may be configured to advance axially on the guidewire and rotate about the guidewire.

[0094] In another embodiment, the present invention relates to a track device that may include an elongated flexible drive shaft and an abrasive element, and optionally a track-type atherosclerotic plaque resection system including the aforementioned sections. The elongated flexible drive shaft may have a proximal portion and a distal portion. The proximal portion may be configured to be drivably coupled to a motor. The distal portion may define a rotation axis. The abrasive element may be fixedly disposed on the distal portion of the elongated flexible drive shaft. The abrasive element includes a first flat side, a second flat side, a front tapered end portion having a front end, and a rear (tapered) end portion having a rear end. The first flat side and the second flat side are located on opposite sides of the rotation axis.

[0095] According to any embodiment, the abrasive element may have an outer surface including a first flat side, a second flat side, a front tapered end portion, and a rear (tapered) end portion. At least a portion of the outer surface includes abrasive particles.

[0096] According to any embodiment, the first flat side and the second flat side may be (substantially) parallel.

[0097] According to any embodiment, the longitudinal length of each of the first flat side and the second flat side may be less than the total longitudinal length of the grinding element.

[0098] According to an embodiment having a front tapered end portion and a rear tapered end portion, the front tapered end portion and the rear tapered end portion of the grinding element tapere in opposite directions along the axis of rotation.

[0099] According to the embodiment having a front tapered end portion and a rear tapered end portion, the cone angle of the front tapered end portion of the grinding element relative to the axis of rotation can be in the range of 10 degrees to 75 degrees, and the cone angle of the rear tapered end portion of the grinding element relative to the axis of rotation can be in the range of -10 degrees to -75 degrees.

[0100] According to any embodiment, the grinding element may be configured to be symmetrical about a rotation axis, configured to have a non-uniform mass distribution about a rotation axis, and configured to have a centroid located on the rotation axis.

[0101] According to any embodiment, the distal portion of the elongated flexible drive shaft includes the distal end of the elongated flexible drive shaft. According to some embodiments, the front tapered portion of the grinding element may terminate at a position proximal to the distal end of the elongated flexible drive shaft. Furthermore, according to other embodiments, a sub-portion of the distal portion of the elongated flexible drive shaft extends distally from the front tapered portion of the grinding element.

[0102] According to some embodiments, the grinding element may include an intermediate section between a front tapered end portion and a rear (tapered) end portion. The intermediate section may have convex side surfaces that are diametrically opposed, the convex side surfaces being circumferentially located between a first flat side and a second flat side facing each other.

[0103] According to some embodiments, the front tapered portion of the grinding element may have a front end, the elongated flexible drive shaft may have a distal end at the distal end of the distal portion of the elongated flexible drive shaft, and the distal end of the elongated flexible drive shaft may terminate at or near the front end of the front tapered portion of the grinding element.

[0104] According to some embodiments, the front tapered end portion of the polishing element transitions directly to the rear (tapered) end portion of the polishing element.

[0105] According to an embodiment having a front tapered end portion and a rear tapered end portion, each of the front tapered end portion and the rear tapered end portion of the grinding element may be at least partially defined by a tapered surface. Each tapered surface may abut and transition to a first flat side and a second flat side.

[0106] According to any embodiment, the grinding element may include an elongated opening configured to receive an elongated flexible drive shaft. The grinding element may be securely attached to the distal portion of the elongated flexible drive shaft at the elongated opening by welding or by adhesive.

[0107] According to any embodiment, the embodiment may optionally include a guidewire, and wherein the elongated flexible drive shaft may have an elongated guidewire lumen configured to slidably receive the guidewire. The elongated flexible drive shaft may be configured to advance axially on the guidewire and rotate about the guidewire.

[0108] In another embodiment, the present invention relates to an abrasive element for use in and / or configuration for use in a track-type atherosclerotic plaque resection system. The abrasive element may include a rotation axis, a first flat side, a second flat side, a front end portion having a front end, and a rear end portion having a rear end. The first flat side and the second flat side are located on opposite sides of the rotation axis.

[0109] According to some embodiments, at least one of the front end portion and the back end portion may be circular.

[0110] According to some embodiments, the grinding element can be longitudinally symmetrical.

[0111] According to some embodiments, the grinding element may be longitudinally asymmetrical.

[0112] As used herein, and unless otherwise stated or supplemented by the context of their use, the terms “basically,” “approximately,” and other degree words are relative modifiers intended to indicate permissible variations with respect to the modified feature, having more physical or functional characteristics than its opposite, and being close to or approximating such physical or functional characteristics.

[0113] While the invention has been described with reference to at least one embodiment, further modifications can be made to the invention within the spirit and scope of this disclosure. Therefore, this application is intended to cover any variations, uses, or adaptations of the invention using the general principles of the invention. Furthermore, this application is intended to cover such deviations from the disclosure within the known or customary practice in the field to which this invention pertains and within the limitations of the appended claims.

Claims

1. A track-type atherosclerotic plaque resection system, comprising: A handheld driver having a motor; An elongated flexible drive shaft having a proximal portion and a distal portion, the proximal portion being drivably coupled to the motor, and the distal portion defining a rotation axis; and A grinding element is fixedly disposed on the distal portion of the elongated flexible drive shaft, wherein the grinding element includes a first flat side, a second flat side, a front tapered end portion having a front end, a rear tapered end portion having a rear end, and an intermediate section between the front tapered end portion and the rear tapered end portion, wherein... The first flat side and the second flat side are located on opposite sides of the rotation axis. The maximum width of the grinding element extends from the first flat side to the second flat side. The intermediate section has convex side surfaces that are diametrically opposed, the convex side surfaces being circumferentially located between the first flat side and the second flat side facing the ground, the diametrically opposed convex side surfaces defining a constant diameter along the length of the intermediate section, and The diameter of each of the front tapering portion at the front end and the rear tapering portion at the rear end is smaller than the constant diameter of the intermediate section.

2. The track-type atherosclerotic plaque resection system according to claim 1, wherein, The abrasive element has an outer surface, which includes a first flat side, a second flat side, a front tapered end portion, and a rear tapered end portion, wherein at least a portion of the outer surface includes abrasive particles.

3. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The first flat side and the second flat side are substantially parallel.

4. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The longitudinal length of each of the first flat side and the second flat side is less than the total longitudinal length of the grinding element.

5. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The front tapering end portion and the rear tapering end portion of the grinding element taper in opposite directions along the axis of rotation.

6. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The front tapered end portion of the grinding element has a cone angle relative to the axis of rotation ranging from 10 degrees to 75 degrees, and the rear tapered end portion of the grinding element has a cone angle relative to the axis of rotation ranging from -10 degrees to -75 degrees.

7. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The grinding element is configured as follows: Symmetric about the axis of rotation The mass distribution around the axis of rotation is non-uniform, and It has a center of mass located on the axis of rotation.

8. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The distal portion of the elongated flexible drive shaft includes the distal end of the elongated flexible drive shaft, and wherein the front tapering portion of the grinding element terminates at a position proximal to the distal end of the elongated flexible drive shaft.

9. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, A sub-portion of the distal portion of the elongated flexible drive shaft extends distally from the front tapering portion of the grinding element.

10. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein: The tapered end portion of the grinding element has a front end. The elongated flexible drive shaft has a distal end at the distal end of the distal portion of the elongated flexible drive shaft, and The distal end of the elongated flexible drive shaft terminates at or near the front end of the tapered portion of the grinding element.

11. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The front tapered end portion of the abrasive element transitions directly into the rear tapered end portion of the abrasive element.

12. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, Each of the front tapered end portion and the rear tapered end portion of the abrasive element is at least partially defined by a tapered surface, wherein each tapered surface abuts and transitions to the first flat side and the second flat side.

13. The track-type atherosclerotic plaque resection system according to claim 1 or 2, wherein, The abrasive element includes an elongated opening configured to receive the elongated flexible drive shaft, the abrasive element being fixedly attached to the distal portion of the elongated flexible drive shaft at the elongated opening by welding or by adhesive.

14. The track-type atherosclerotic plaque resection system according to claim 1 or 2, comprising a guidewire, and wherein, The elongated flexible drive shaft has an elongated guidewire lumen configured to slidably receive the guidewire, and the elongated flexible drive shaft is configured to advance axially on the guidewire and rotate about the guidewire.

15. A track device, comprising: An elongated flexible drive shaft having a proximal portion and a distal portion, the proximal portion being configured to be drivably coupled to a motor, and the distal portion defining a rotation axis; and A grinding element is fixedly disposed on the distal portion of the elongated flexible drive shaft, wherein the grinding element includes a first flat side, a second flat side, a front tapered end portion having a front end, a rear tapered end portion having a rear end, and an intermediate section between the front tapered end portion and the rear tapered end portion, wherein... The first flat side and the second flat side are located on opposite sides of the rotation axis. The maximum width of the grinding element extends from the first flat side to the second flat side. The intermediate section has convex side surfaces that are diametrically opposed, the convex side surfaces being circumferentially located between the first flat side and the second flat side facing the ground, the diametrically opposed convex side surfaces defining a constant diameter along the length of the intermediate section, and The diameter of each of the front tapering portion at the front end and the rear tapering portion at the rear end is smaller than the constant diameter of the intermediate section.

16. The track device according to claim 15, wherein, The abrasive element has an outer surface, which includes a first flat side, a second flat side, a front tapered end portion, and a rear tapered end portion, wherein at least a portion of the outer surface includes abrasive particles.

17. The track device according to claim 15 or 16, wherein, The first flat side and the second flat side are substantially parallel.

18. The track device according to claim 15 or 16, wherein, The longitudinal length of each of the first flat side and the second flat side is less than the total longitudinal length of the grinding element.

19. The track device according to claim 15 or 16, wherein, The front tapering end portion and the rear tapering end portion of the grinding element taper in opposite directions along the axis of rotation.

20. The track device according to claim 15 or 16, wherein, The front tapered end portion of the grinding element has a cone angle relative to the axis of rotation ranging from 10 degrees to 75 degrees, and the rear tapered end portion of the grinding element has a cone angle relative to the axis of rotation ranging from -10 degrees to -75 degrees.

21. The track device according to claim 15 or 16, wherein, The grinding element is configured as follows: Symmetric about the axis of rotation The mass distribution around the axis of rotation is non-uniform, and It has a center of mass located on the axis of rotation.

22. The track device according to claim 15 or 16, wherein, The distal portion of the elongated flexible drive shaft includes the distal end of the elongated flexible drive shaft, and wherein the front tapering portion of the grinding element terminates at a position proximal to the distal end of the elongated flexible drive shaft.

23. The track device according to claim 15 or 16, wherein, A sub-portion of the distal portion of the elongated flexible drive shaft extends distally from the front tapering portion of the grinding element.

24. The track device according to claim 15 or 16, wherein: The tapered end portion of the grinding element has a front end. The elongated flexible drive shaft has a distal end at the distal end of the distal portion of the elongated flexible drive shaft, and The distal end of the elongated flexible drive shaft terminates at or near the front end of the tapered portion of the grinding element.

25. The track device according to claim 15 or 16, wherein, The front tapered end portion of the abrasive element transitions directly into the rear tapered end portion of the abrasive element.

26. The track device according to claim 15 or 16, wherein, Each of the front tapered end portion and the rear tapered end portion of the abrasive element is at least partially defined by a tapered surface, wherein each tapered surface abuts and transitions to the first flat side and the second flat side.

27. The track device according to claim 15 or 16, wherein, The grinding element includes an elongated opening configured to receive the elongated flexible drive shaft, the grinding element being fixedly attached to the distal portion of the elongated flexible drive shaft at the elongated opening by welding or by adhesive.

28. The track device according to claim 15 or 16, comprising a guide wire, and wherein, The elongated flexible drive shaft has an elongated guidewire lumen configured to slidably receive the guidewire, and the elongated flexible drive shaft is configured to advance axially on the guidewire and rotate about the guidewire.

29. An abrasive element for use in a track-type atherosclerotic plaque resection system, comprising a rotation axis, a first flat side, a second flat side, a front end portion having a front end, a rear end portion having a rear end, and an intermediate section between the front end portion and the rear end portion, wherein, The first flat side and the second flat side are located on opposite sides of the rotation axis. The maximum width of the grinding element extends from the first flat side to the second flat side. The intermediate section has convex side surfaces that are diametrically opposed, the convex side surfaces being circumferentially located between the first flat side and the second flat side facing the ground, the diametrically opposed convex side surfaces defining a constant diameter along the length of the intermediate section, and The diameter of each of the front portion at the front end and the rear portion at the rear end is smaller than the constant diameter of the intermediate section.

30. The grinding element according to claim 29, wherein, At least one of the front end portion and the rear end portion is circular.

31. The grinding element according to claim 29 or 30, wherein, The grinding element is longitudinally symmetrical.

32. The grinding element according to claim 29 or 30, wherein, The grinding element is longitudinally asymmetrical.

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