阅读说明：本技术 用于在旋转医疗装置的驱动轴中产生轨道运动的装置和方法 (Device and method for generating an orbital motion in a drive shaft of a rotary medical device ) 是由 约瑟夫·P·希金斯 凯拉·J·艾彻尔斯 杰弗里·R·斯通 于 2019-10-08 设计创作，主要内容包括：描述了允许实现大于静止直径的工作直径并在高速旋转期间激发流体循环的装置、方法和系统。驱动轴的阻力系数增加,并且在一些实施例中质量增加。除了其它优点之外,具有与偏心元件集成和/或附接到其上的偏心元件的所得驱动轴将以低于实现轨道运动所需的旋转速度的旋转速度实现轨道运动,而不增加阻力系数。以相对较低的旋转速度在流体流量和/或流体搅动上的伴随增加是再一优点。因此,这些特征可以允许使用较小直径的研磨元件,这在小的和/或高度曲折的血管中是有利的。(Devices, methods, and systems are described that allow for achieving a working diameter greater than a resting diameter and exciting fluid circulation during high speed rotation. The drag coefficient of the drive shaft increases and in some embodiments the mass increases. Among other advantages, the resulting drive shaft having an eccentric element integrated with and/or attached to the eccentric element will achieve orbital motion at a rotational speed that is lower than the rotational speed required to achieve orbital motion without increasing the drag coefficient. The concomitant increase in fluid flow and/or fluid agitation at relatively low rotational speeds is a further advantage. Thus, these features may allow for the use of smaller diameter abrasive elements, which may be advantageous in small and/or highly tortuous vessels.)

1. A rotary medical device having a prime mover operatively rotatably connected to a drive shaft, the drive shaft having an axis of rotation and being adapted to achieve a working diameter greater than its rest diameter during high speed rotation, the rotary medical device comprising:

a grinding element operably attached to the drive shaft and comprising a center of mass radially offset from an axis of rotation of the drive shaft;

a surface defect formed on at least a portion of an exterior surface of the drive shaft, wherein the surface defect is formed proximal and distal to the abrasive element, and wherein the surface defect is adapted to increase a drag coefficient of the drive shaft.

2. The rotating medical device of claim 1, further comprising a polymeric cover layer covering at least a portion of an exterior surface of the drive shaft to adjust a drag coefficient of the drive shaft.

3. The rotational medical device of claim 1, wherein the surface defects are formed by a laser device.

4. A rotary medical device having a drive shaft and an operatively connected prime mover adapted to rotate the drive shaft and an abrasive element connected to the drive shaft, the drive shaft having an outer diameter and an axis of rotation, the rotary medical device comprising:

a proximal spring resistance element surrounding the drive shaft and comprising an outer diameter greater than an outer diameter of the drive shaft.

5. The rotational medical device of claim 4, further comprising:

a distal spring resistance element surrounding the drive shaft and comprising an outer diameter greater than an outer diameter of the drive shaft.

6. The rotary medical device of claim 4, wherein the abrasive element comprises an eccentric crown and a center of mass radially spaced from the rotational axis of the drive shaft, and wherein the proximal spring resistance element comprises a center of mass located on the rotational axis of the drive shaft.

7. The rotary medical device of claim 5, wherein the abrasive element comprises an eccentric crown, and wherein the proximal spring resistance element and the distal spring resistance element both comprise a center of mass located on the rotational axis of the drive shaft.

8. The rotary medical device of claim 5, wherein a center of mass of at least one of the proximal spring resistance element and the distal spring resistance element is radially spaced from an axis of rotation of the drive shaft.

9. The rotary medical device of claim 8, wherein the centers of mass of the eccentric crowns, the proximal spring resistance element, and the distal spring resistance element lie on the same longitudinal plane.

10. The rotary medical device of claim 8, wherein a center of mass of the abrasive element is rotationally spaced from a center of mass of the proximal spring resistance element.

11. The rotary medical device of claim 9, wherein a center of mass of the abrasive element is rotationally spaced from a center of mass of the distal spring resistance element.

12. The rotary medical device of claim 5, wherein the abrasive element is longitudinally spaced from at least one of the proximal and distal spring resistance elements.

13. The rotary medical device of claim 4, wherein the grinding element is longitudinally spaced from the proximal spring resistance element.

14. The rotary medical device of claim 4, wherein the grinding element is not longitudinally spaced from the proximal spring resistance element.

15. The rotary medical device of claim 5, wherein the grinding element is not longitudinally spaced from the distal spring resistance element.

16. The rotary medical device of claim 4, wherein the abrasive element comprises a length less than a length of the proximal spring resistance element.

17. The rotary medical device of claim 5, wherein the proximal spring resistance element and the distal spring resistance element each comprise a mass.

18. A rotary medical device having a drive shaft and an operatively connected prime mover adapted to rotate the drive shaft and an abrasive element having a center of mass and attached to the drive shaft, the drive shaft having an outer diameter and an axis of rotation, the rotary medical device comprising:

a proximal spring resistance element partially encircling the drive shaft such that a portion of the drive shaft is not encircled and, in combination with the portion of the drive shaft that is not encircled, comprises an outer diameter that is greater than the outer diameter of the drive shaft alone.

19. The rotational medical device of claim 17, further comprising:

a distal spring resistance element partially encircling the drive shaft such that a portion of the drive shaft is not encircled and, in combination with the portion of the drive shaft that is not encircled, includes an outer diameter that is greater than an outer diameter of the drive shaft.

20. The rotary medical device of claim 18, wherein the abrasive element is an eccentric crown, and wherein the centers of mass of the eccentric crown, proximal spring resistance element, and distal spring resistance element are all radially spaced from the axis of rotation of the drive shaft.

21. The rotary medical device of claim 19, wherein the centers of mass of the eccentric crowns, the proximal spring resistance element, and the distal spring resistance element lie on the same longitudinal plane.

22. The rotary medical device of claim 19, wherein a center of mass of the eccentric crown is rotationally spaced from a center of mass of the proximal spring resistance element.

23. The rotary medical device of claim 19, wherein a center of mass of the abrasive element is rotationally spaced from a center of mass of the distal spring resistance element.

24. The rotary medical device of claim 18, wherein the abrasive element is longitudinally spaced from at least one of the proximal and distal spring resistance elements.

25. The rotary medical device of claim 17, wherein the grinding element is longitudinally spaced from the proximal spring resistance element.

26. The rotary medical device of claim 17, wherein the grinding element is not longitudinally spaced from the proximal spring resistance element.

27. The rotary medical device of claim 18, wherein the grinding element is not longitudinally spaced from the distal spring resistance element.

28. A rotary medical device having a drive shaft and an operatively connected prime mover adapted to rotate the drive shaft and an abrasive element having a center of mass and attached to the drive shaft, the drive shaft having an outer diameter and an axis of rotation, the rotary medical device further comprising:

at least one proximal resistance element comprising a center of mass and operatively attached to the drive shaft proximal to the abrasive element; and at least one distal resistance element comprising a center of mass and operatively attached to the drive shaft distal to the abrasive element.

29. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element comprise symmetrical paddle wheels comprising a plurality of radial protrusions protruding radially away from the drive shaft.

30. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element comprise asymmetric paddle wheels comprising a plurality of radial protrusions protruding radially away from the drive shaft.

31. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element comprise asymmetric paddle wheels comprising a plurality of radial protrusions protruding radially away from the drive shaft, wherein at least one of the radial protrusions comprises a curved portion at a distal end.

32. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element are non-rotatably operatively attached to the drive shaft.

33. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element are rotatably operatively attached to the drive shaft.

34. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element each comprise one or more balls operably attached to the drive shaft.

35. The rotary medical device of claim 28, wherein the at least one proximal resistance element and the at least one distal resistance element each comprise one or more loops operably attached to the drive shaft.

36. An eccentric abrasive crown for a rotational atherectomy device having a prime mover operatively and rotationally connected with a drive shaft, wherein the abrasive crown is attached to the drive shaft, the eccentric abrasive crown comprising:

a body portion operatively connected with the drive shaft; and a hydrofoil extension extending radially away from the body portion and the drive shaft, wherein the hydrofoil extension includes a bend portion and is adapted to bend against the body portion to achieve a delivery position and extend to achieve a working position.

37. The eccentric abrasive crown of claim 36 wherein said bent portion of said hydrofoil extension includes a hinge.

38. The eccentric abrasive crown of claim 37 wherein said hinge is biased to achieve said working position.

39. The eccentric abrasive crown of claim wherein said hydrofoil extension comprises a shape memory material biased to achieve said working position.

Technical Field

The present invention relates to drive shafts for rotating medical devices, including but not limited to orbital atherectomy devices and systems.

Background

Rotating medical devices require a drive shaft that rotates at a high rotational speed. For rotational atherectomy devices, it is known that adding an abrasive element to the drive shaft will achieve orbital motion during high speed rotation, where the abrasive element has a center of mass that is radially offset from the longitudinal axis of the drive shaft. One of the features of the orbital motion is that the grinding elements obtain a working diameter during high speed rotation that is greater than the resting diameter of the grinding elements. In these known systems, the abrasive elements having a radially offset center of mass are referred to as "eccentric". In known devices, such eccentricity in the radial offset centroid is achieved using the geometric asymmetry of the abrasive element, the asymmetric mounting of the abrasive element to the drive shaft, and/or moving the centroid of the symmetric abrasive element by, for example, inserting a plug of high density material into the abrasive element and/or removing some material from the abrasive element.

Fig. 1 shows a prior art device 100 that includes a drive shaft 20 that is symmetrical along its length. Mounted at the distal end of the drive shaft 20 is a symmetrical and concentric burr 12, wherein the burr 12 includes a center of mass C located on the rotational axis a of the drive shaft 20. The drive shaft translates within the lumen of the catheter 13 and is connected at the proximal end to a prime mover located within the handle 10. The guide wire 15 is shown translating through the lumen of the drive shaft 20 and through the lumen defined by the burr 12. In this case, there is no asymmetry or eccentricity, and the drive shaft 20 will not thereby realize an orbital rotary motion unless disturbed by hitting an asymmetric object (such as a lesion). Thus, the static diameter of the drive shaft and the burr will effectively be the same as the undisturbed working diameter of the drive shaft and the burr during high speed rotation.

As shown in fig. 2 and 3, the technique was developed to form an enlarged and abrasive coated portion of a drive shaft in which the wire turns of the drive shaft have been stretched by a shaping mandrel, as is well known in the art. The enlarged portion of the drive shaft may be symmetrical and concentric, in which case the centre of mass will lie on the axis of rotation of the drive shaft and will not orbit. Alternatively, the enlarged portion of the drive shaft may be asymmetric and eccentric with a center of mass spaced radially from the axis of rotation of the drive shaft. This eccentricity causes the eccentric enlarged drive shaft portion to orbit, with the working diameter described by the enlarged portion being greater than its rest diameter.

Thus, similar to fig. 1, fig. 2 also provides a handle 10, an elongated flexible drive shaft 20, and an elongated catheter 13 extending distally from the handle 10. The enlarged diameter portion 28 is formed by the wire turns of the drive shaft 20. The drive shaft 20 is formed or constructed from helically wound wire turns. As is well known in the art, the drive shaft 20 may include one layer of helically coiled wire or two layers of helically coiled wire turns or wires, as is well known in the art. In some cases, embodiments of two layers of wire turns may include oppositely wound coils, and in other cases, two layers of wire turns or wires may be wound in the same direction. All such embodiments are within the scope of the present invention.

Fig. 2 also provides a guide wire 15 and a fluid supply line 17 for introducing a cooling and/or lubricating solution. A pair of fiber optic cables 25 may be provided to monitor the rotational speed and the handle may include a control knob 11 to advance and/or retract the drive shaft.

Fig. 3 illustrates one embodiment of the enlarged drive shaft portion 28 of fig. 2 in a cut-away perspective view. Here, the enlarged wire turns or wires 41 of the drive shaft 20 are visible, as is the exemplary abrasive coating 24 adhered to the drive shaft. As mentioned above, the center of mass of enlarged portion 28 may be on the axis of rotation a, and thus concentric and not suitable for creating an orbital motion during high speed rotation. Alternatively, the center of mass of the enlarged portion 28 may be radially spaced from the rotational axis a of the drive shaft 20 and thus adapted to achieve orbital motion during high speed rotation.

Fig. 4 provides another alternative known in the art, wherein the crown 28A is mounted to the drive shaft 20. As shown, the crown 28A is eccentric and/or mounted eccentrically to the drive shaft 28A to provide a center of mass C located radially away from the rotational axis a of the drive shaft 20. As with the eccentric embodiment discussed above in connection with fig. 3 and 4, during high speed rotation of the drive shaft 20, the eccentric crown 28A will be urged into orbital motion, wherein it describes a working diameter greater than its resting diameter during rotation. As will be appreciated by those skilled in the art, the centroid C position can be manipulated by modifying multiple elements, including but not limited to providing a hollow chamber 30 within the crown 28A. If present, the size and/or shape of the hollow chamber 30 may be varied to manipulate the centroid C location.

Fig. 5 shows a final exemplary prior art embodiment, in which the required eccentricity to produce the orbital motion is provided by the pre-curved section 28B of the drive shaft 20. This arrangement radially spaces the centroid C of the pre-bend section and accompanying abrasive section 24, which may be an abrasive coating as shown or a burr or crown attached thereto, from the axis of rotation a of the drive shaft 20. Thus, the high speed rotation of the drive shaft 20 will result in a trajectory of the grinding section 24 having a working diameter greater than its rest diameter.

Fig. 6 shows a cross-sectional view of a wire turn or wire 41 of a prior art drive shaft 20 and a lumen L defined therethrough. Generally, such prior art devices are symmetrical and concentric about the axis of rotation, and thus the center of mass at any point along the length of the drive shaft will be located on the axis of rotation of the drive shaft and will not induce or achieve orbital motion if not more.

It is desirable to provide a mechanism for achieving orbital motion and/or enhanced fluid flow at rotational speeds significantly lower than that permitted by known devices.

Various embodiments of the present invention address these problems, among others.

Further, we realize that the following patents and applications, each of which is assigned to Cardiovasular Systems, Inc. and which is incorporated herein in its entirety, may include Systems, methods, and/or apparatus that may be used with various embodiments of the presently disclosed subject matter:

U.S. Pat. No. 5, 9,468,457, "ATHERECTOMY DEVICE WITH ECCENTRIC CROWN";

U.S. Pat. No. 9,439,674, "ROTATONAL ATHERECTOMY DEVICE WITH EXCHANGEABLE DRIVE SHAFT AND MESHING GEARS";

U.S. Pat. No. 4, 9,220,529, "ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR";

U.S. Pat. No. 4, 9,119,661, "ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR";

U.S. Pat. No. 4, 9,119,660, "ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR";

U.S. Pat. No. 9,078,692, "ROTATONAL ATHERECTOMY SYSTEM";

U.S. Pat. No.6,295,712, "ROTATONAL ATHERECTOMY SYSTEM";

U.S. Pat. nos. 6,494,890, "ECCENTRIC ROTATIONAL ATHERECTOMY DEVICE";

U.S. Pat. No.6,132,444, "ECCENTRIC DRIVE SHAFT FOR ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE";

U.S. Pat. No. 3, 6,638,288, "ECCENTRIC DRIVE SHAFT FOR ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE";

U.S. Pat. No. 5,314,438, "ABRASIVE DRIVE SHAFT DEVICE FOR ROTATONAL ATHERECTOMY";

U.S. Pat. No.6,217,595, "ROTATONAL ATHERECTOMY SYSTEM";

U.S. Pat. No. 5,5,554,163, "ATHERECTOMY DEVICE";

U.S. Pat. No. 5,7,507,245, "ROTATONAL ANGIOPLASTY DEVICE WITH ABRASIVE CROWN";

U.S. Pat. No.6,129,734, "ROTATONAL ATHERECTOMY DEVICE WITH RADIALLY EXPANDABLE PRIME MOVER COUPLING";

U.S. patent application 11/761,128, "ECCENTRIC ABRADING HEAD FOR HIGH-SPEED rotation outside recording DEVICES";

U.S. patent application 11/767,725, "SYSTEM, APPATUS AND METHOD FOR OPENING AN OCCLED LESION";

U.S. patent application 12/130,083, "ECCENTRIC ABRADING ELEMENT FOR HIGH-SPEED rotation outside recording DEVICES";

U.S. patent application 12/363,914, "Multi-Material ABRADING HEAD FOR ATHERECTOMY DEVICES HAVING LATERALLY DISPLACED CENTER OF MASS";

U.S. patent application 12/578,222, "ROTATONAL ATHERECTOMY DEVICE WITH PRE-CURVED DRIVE SHAFT";

U.S. patent application 12/130,024, "ECCENTRIC ABRADING AND CUTTING HEAD FOR HIGH-SPEED rotation outside recording DEVICES";

U.S. patent application 12/580,590, "ECCENTRIC ABRADING AND CUTTING HEAD FOR HIGH-SPEED rotation outside recording DEVICES";

U.S. patent application 29/298,320, "ROTATONAL ATHERECTOMY ABRASIVE CROWN";

U.S. patent application 29/297,122, "ROTATONAL ATHERECTOMY ABRASIVE CROWN";

U.S. patent application 12/466,130, "BIDIRECTIONAL EXPANDABLE HEAD FOR ROTATIONARY DEVICE"; and

U.S. patent application 12/388,703, "ROTATONAL ATHERECTOMY SEGMENTED ABRADING HEAD AND METHOD TO IMPROVE ABRADING EFFICIENCY".

Disclosure of Invention

Devices, methods, and systems are described that allow for achieving a working diameter greater than a resting diameter and exciting fluid circulation during high speed rotation. The drag coefficient of the drive shaft increases and in some embodiments the mass increases. Among other advantages, the resulting drive shaft having an eccentric element integrated with and/or attached to the eccentric element will achieve orbital motion at a rotational speed that is lower than the rotational speed required to achieve orbital motion without increasing the drag coefficient. The concomitant increase in fluid flow and/or fluid agitation at relatively low rotational speeds is a further advantage. In fact, the increased fluid agitation ultimately increases the lumen orbiting frequency of the rotating system and has a much faster rate of increase than known orbiting systems when orbiting is achieved over a wide range of rotational speeds. Thus, these features may allow for the use of smaller diameter abrasive elements, which may be advantageous in small and/or highly tortuous vessels.

The drag coefficient may be increased by a variety of mechanisms, including but not limited to the following:

enhancing or adjusting the surface roughness of the outwardly facing surface of the drive shaft, such as wires forming the structure of the drive shaft;

a resistance element is added along and in combination with a drive shaft adapted to achieve orbital motion via an eccentric abrasive element (such as a crown) or by other means, including but not limited to those disclosed in co-pending application filed on even date herewith, i.e., U.S. application No.16/594834, the disclosure of which is incorporated herein by reference in its entirety.

When eccentric abrasive elements are present, these added resistance elements may be placed proximal and/or distal to the eccentric abrasive elements, and may include springs, coiled wire masses, paddles or paddle wheels or braids, balls, loops, etc., and may be fixed to the drive shaft or may be free to rotate.

The figures and the detailed description that follow more particularly exemplify these and other embodiments of the invention.

Drawings

Fig. 1 is a cross-sectional view of a prior art device.

Fig. 2 is a perspective view of a prior art device.

Fig. 3 is a perspective cut-away view of a prior art device.

Fig. 4 is a cross-sectional view plus a cutaway view of a prior art device.

Fig. 5 is a cross-sectional view plus a cutaway view of a prior art device.

Fig. 6 is a cross-sectional view of a prior art drive shaft with a guide wire.

Fig. 7 is a cross-sectional view of one embodiment of the present invention.

Fig. 8A is a cross-sectional view of one embodiment of the present invention.

Fig. 8B is a cross-sectional view of one embodiment of the present invention.

Fig. 8C is an end view along the axis of rotation of the drive shaft of the present invention showing an exemplary location of the center of mass.

Fig. 9 is an illustration of a working example of an embodiment of the present invention.

Fig. 10A is a front view of one embodiment of the present invention.

Fig. 10B is a front view of one embodiment of the present invention.

Fig. 10C is a front view of one embodiment of the present invention.

FIG. 11 is a cross-sectional view of one embodiment of the present invention.

FIG. 12 is an illustration of an example of the operation of one embodiment of the present invention.

Fig. 13 is a cross-sectional view of one embodiment of the present invention.

Fig. 14 is a cross-sectional view of one embodiment of the present invention.

Fig. 15A is a perspective view of one embodiment of the present invention.

Fig. 15B is a perspective view of one embodiment of the present invention.

Detailed Description

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Various embodiments of a rotary drive shaft for a rotary medical device, such as a rotational atherectomy system, are provided. Each embodiment produces an orbital motion that results from features integrated with the drive shaft, rather than from an attached grinding element.

First, it should be understood that, as used herein and defined herein, the word "eccentricity" and variants thereof refer to: (1) a difference in position between the geometric center of the drive shaft and the axis of rotation of the drive shaft, or (2) a difference in position between the center of mass of the drive shaft and the axis of rotation of the drive shaft.

Further, it should be understood that, as used herein and defined herein, the term "orbital motion" refers to an orbital element, such as a drive shaft, that achieves a working diameter that is greater than its resting diameter, and wherein orbital motion is caused by an eccentric element, such as a mass or eccentric abrasive element, mounted on or in or along the drive shaft, in some embodiments integrated in, along, or on a wire turn or wire of the drive shaft. The resulting motion of the drive shaft during the orbital motion may also be referred to as a standing wave having a predictable, customizable length and shape.

Mechanism for increasing the coefficient of resistance of a drive shaft rotating in a fluid

1. Modifying or adjusting surface roughness

It is well known that the drag coefficient of a surface can be modified or adjusted to increase and/or decrease the surface roughness and can be measured by reference to, inter alia, the resulting reynolds number. For example, if the Reynolds number is 4x10⁴To 4x10⁵In a range of (a), a smoother surface may result in a higher resistance coefficient. At 4x10⁵Above the reynolds number of (a), a rougher surface may result in a higher resistance coefficient. In general, surface roughness will increase the drag coefficient of a streamlined object in turbulent flow environments. For objects such as cylinders or spheres, an increase in surface roughness may increase or decrease the drag coefficient, depending on the reynolds number.

For example, a laser or other device may be used to create a surface defect 150 on at least a portion of the outer surface of the drive shaft 20, including an exemplary eccentric portion embodied as an abrasive element in the form of an eccentric crown 28A as shown in fig. 7 and fig. 4. In general, the surface defects may include pits or depressions in the exterior surface. Alternatively, some or all of the existing surface defects may be smoothed by applying a cover layer 160, such as a polymeric protective layer or sheath (shown in dashed lines in fig. 7). Based on the reynolds number at which the drive shaft 20 of the present subject matter spins and orbits in a fluid, such as water, the drag coefficient may be increased, which one of skill will recognize will increase the tendency of the rotating drive shaft to achieve orbital motion.

Increasing the drag coefficient of the drive shaft 20 rotating in the fluid through the mechanisms described herein will be, among other things:

1. enhanced rotational movement of the fluid about the rotating drive shaft 20 in the environment of the rotating drive shaft 20 as compared to a drive shaft 20 having a lower coefficient of resistance;

2. due to the enhanced fluid circulation of item 1 above (which would tend to move the drive shaft 20 away from its axis of rotation a and into orbital motion), orbital motion is achieved at a lower rotational speed than a drive shaft with a lower coefficient of resistance;

3. due to the increased pressure gradient driven by the enhanced fluid circulation of item 1 above, orbital motion is achieved at a lower rotational speed than a drive shaft 20 having a lower coefficient of resistance.

2. Resistance elements are added along the shaft to increase its drag coefficient.

Typically, a resistance element may be added to the outside of the rotating drive shaft to increase its coefficient of resistance as it rotates within the fluid. In some cases, as shown in fig. 8, the resistance element may include at least one spring 200 having an outer diameter D1 that is greater than the outer diameter D2 of the drive shaft 20 to which the at least one spring 200 is attached. The spring 200 in this embodiment is preferably highly flexible so that the stiffness of the drive shaft does not increase significantly. Further, the spring may be relatively light, such that the mass increase due to the spring is minimal. Thus, this embodiment increases the drag coefficient primarily by increasing the diameter and surface "roughness" of the spring.

Thus, fig. 8 provides a proximal spring 200P secured to the drive shaft 20, which is proximal with respect to the eccentric abrasive element shown as eccentric crown 28A operably attached to the drive shaft 20. Further, an optional distal spring 200D is shown secured to the drive shaft 20 distal to the eccentric crown 28A. In both cases, the springs 200P, 200D are shown longitudinally spaced from the eccentric crown 28A. However, it should be understood that one or both of the springs 200P, 200D may contact the eccentric crown 28A and thus not be spaced therefrom. Additionally, the springs 200P and 200D are shown circumferentially surrounding the drive shaft 20 when operatively connected therewith. In general, springs 200P and 200D may be concentric, i.e., center of mass C_PAnd C_DWill lie on the axis of rotation a of the drive shaft 20 along the length of the springs 200P and/or 200D and the centre of mass C of the eccentric crown will be radially offset from the axis of rotation a.

Alternatively, one or both of the springs 200P, 200D may be partially circumferentially wound around the drive shaft 20. In this case, the center of mass of the partially enclosed spring will be radially offset from the axis of rotation of the drive shaft along the length of the partially enclosed spring. FIG. 8B shows an exemplary drive shaft and center of mass C with partially wound proximal and distal springs 200P and 200D_P、C_DAnd the position of the center of mass C of the eccentric crown 28A. It is also noteworthy that the outer diameter D3 of the drive shaft 20 plus the partially wound springs 200P, 200D is greater than the outer diameter D2 of the drive shaft. FIG. 8B illustrates an exemplary device, wherein center of mass C, C_PAnd C_DAlong the same longitudinal plane (i.e., at centroid position C, C)_PAnd C_DThere is no rotational angle therebetween).

Those skilled in the art will appreciate that the embodiment of FIG. 8A may be modified by adding the mass of the springs 200P, 200D in a radially asymmetric distribution, thereby modifying the center of mass C_PAnd C_DOne or both are radially displaced from the rotational axis a of the drive shaft 20. Centroid C, C_PAnd C_DMay be along the same longitudinal plane, i.e., at centroid C, C_PAnd C_DThere is no rotation angle between the positions.

FIG. 8C illustrates the centroid C, C of either of the embodiments shown in FIGS. 8A and 8B_PAnd C_DExemplary locations of (a). Here, exemplary rotation angles α and β are set at: (1) eccentric crown center of mass C and proximal spring center of mass C_PAnd (2) an eccentric crown center of mass C and a distal spring center of mass C_DBetween the positions of (a) and (b). In these embodiments, centroid C, C_PAnd C_DMay be longitudinally and rotationally spaced apart, in combination with increased diameters D1 and/or D3, to assist in exciting orbital motion at a lower rotational speed than an unmodified drive shaft.

Thus, in certain embodiments, the abrasive elements (e.g., crowns) need not be eccentric, but rather may be concentric with a center of mass on the rotational axis of the drive shaft 20, with the center of mass C being radially offset and in some cases rotationally separated_PAnd/or C_DIn conjunction with the increased drag coefficient discussed above, the drive shaft 20 is driven off-axis and into orbital motion.

Finally, as shown, it is generally preferred that the springs 200P, 200D comprise a length greater than the length of the eccentric abrasive element (i.e., eccentric crown 28A) to maximize or optimize the resulting increase in resistance. In other embodiments, one or both of the springs 200P, 200D may be of equal length or may comprise different lengths. Further, the length of the springs 200P and/or 200D may be equal to or less than the length of the eccentric crown 28A or eccentric abrasive element.

The embodiment shown in fig. 8A will be discussed further below.

Working example 1

The proximal spring 200P and the distal spring 200D of fig. 8A are placed on the proximal side and the distal side of the 1.25mm eccentric crown 28A along the rotating drive shaft 20 shown in fig. 8 (modified device) and then rotated at various speeds. The known rotary drive shaft 20 without spring and the 1.25mm eccentric crown 28A then rotate at the same speed (unmodified device). At the tested rotational speeds, the orbital frequency of the two sets of conditions was monitored.

Fig. 9 shows the measurement results of working example 1.

Unmodified devices (i.e., devices without springs) are not capable of orbital motion at relatively low speeds (1000Hz) or moderate rotational speeds (1500Hz), and are only capable of very low frequency orbital motion at a specified high speed of 2000 Hz.

On the other hand, at all test speeds, the modified device produced orbital motion and was at a higher orbital frequency. The data shows a linear relationship between rotational speed and orbital frequency.

One of the most important conclusions based on these data is that the addition of springs 200P, 200D of relatively low mass but with an outer diameter D1 greater than the outer diameter D2 of the drive shaft 20 increases the drag coefficient of the drive shaft 20, which in turn results in an orbital motion at a significantly lower rotational speed and a significantly greater orbital frequency than the unmodified drive shaft and eccentric crown combination.

Thus, the resistance element used herein may include an increase in diameter over the diameter of the drive shaft 20 as a mechanism to achieve an increased coefficient of resistance and thus an orbital motion with a higher frequency at a lower rotational speed than is possible in known devices or systems.

There are many possible mechanisms to increase the drag coefficient of the drive shaft, and this may depend on increasing the outer diameter of the drive shaft and/or the increase in mass and/or the relative position of the resulting centroid as in the working example. Additional exemplary resistance elements that may be added to the drive shaft to increase the coefficient of resistance are as follows.

Adding a resistance element non-rotatably fixed to a shaft

An exemplary resistance element may be added to the drive shaft 20 having arms or radial projections 302 that extend radially outward as illustrated in fig. 10A-10C as an exemplary paddle wheel 300 (fig. 10A). However, any resistance element, including radial projections, which may be straight and/or curved and/or cupped, will serve to increase the coefficient of resistance to further enhance fluid circulation.

Fig. 10A provides a set of symmetrical radial projections 302, wherein the center of mass C will be on the rotational axis a of the drive shaft 20 when attached to the drive shaft. In this case, the coefficient of resistance and the resulting impulse of the drive shaft 20 into orbital motion is due to the increased fluid flow during rotation. Adjacent radial projections 302 are equally spaced about the drive shaft 20. Alternatives may include unequal spacing between adjacent radial projections 302.

Fig. 10B includes an asymmetric distribution of the radial projections 302 about the paddle wheel resistance element 320 such that the center of mass C is now radially offset from the nominal or stationary rotational axis a of the drive shaft, thereby facilitating orbital motion in addition to enhanced fluid flow.

Finally, fig. 10C provides an exemplary set of cup-shaped or curved radial protrusions 330 that may be distributed symmetrically or asymmetrically about the drive shaft 20, with the center of mass positioned on or radially away from the drive shaft axis of rotation a, respectively.

In the embodiment of fig. 10A-10C, further asymmetry, and thus a radially displaced centroid with respect to the axis of rotation a, may be achieved by modifying some of the radial projection lengths so that they are not all equal and/or increasing the mass of one or more of the radial projections.

The embodiment of fig. 10A-10C may be non-rotatably secured to the drive shaft 20. One or more of these resistance elements may be fixed to the drive shaft 20. When the eccentric abrasive element is attached to the drive shaft, one or more resistance elements may be secured to the proximal and/or distal side of the eccentric abrasive element. When the drive shaft includes an eccentricity derived from other means, such as the drive shaft wire structure itself or a mass plug inserted in the wire, the resistance element may be similarly fixed proximal and/or distal to the eccentric region integrated into the drive shaft 20.

Alternatively, a resistance element comprising a radial protrusion may be formed from the outer surface of the single wire 41 of the drive shaft 20, with the resistance element extending therefrom. As described above, the radially projecting resistance elements may permanently extend radially away from the drive shaft 20, or may include an offset flat profile until the drive shaft 20 rotates at a threshold speed, which causes the resistance elements to extend radially and affect the resistance coefficient.

The adjustment of the resistance coefficient may be made by the surface area of the individual radial projections of the resistance elements, the number of radial projections on each resistance element, the shape and/or curvature of the radial projections. Further, the radial protrusion may be adapted to achieve a working configuration whereby the radial protrusion is biased to rest substantially flat against the outer surface of the drive shaft 20 and/or to coil around the drive shaft 20. Rotation of the drive shaft 20 may then move the radial projections into their working positions to achieve the working configuration.

Adding a resistance element rotatably operatively attached to a shaft

Such an embodiment for adding or adjusting to optimize the drag coefficient is similar to the embodiment of fig. 10A-10C, except that the radially protruding embodiment may be rotatably operatively attached to the drive shaft 20.

2C. increasing mass and outside diameter along drive shaft

Adding mass along the drive shaft 20 will increase the centrifugal force which will keep the standing wave of the drive shaft about the rail in place and enhance the amplitude or working diameter of the deflection about the rail shaft 20. The greater the orbit diameter or deflection, the more fluid is circulated for rotation, thus producing orbital motion at a lower rotational speed than an unmodified known drive shaft. An exemplary mechanism for increasing the quality for the purpose is as follows:

a coiled wire or wire mass element attached to a shaft having an eccentric crown.

In addition to the eccentric crowns, a resistance element comprising a coiled wire or wire mass or spring 200 (e.g., a wrap spring) may be placed over or around at least a portion of the drive shaft 20 at a point distal and/or proximal of the eccentric crown 28A. In all cases, the applicant has found that by placing the mass or spring 200 in the vicinity of the eccentric crown 28A, the best results are obtained. Most preferably, at least the proximal and/or distal mass or spring is in touching contact with the eccentric crown. Fig. 11 illustrates such a configuration, wherein the exemplary proximal spring 200P includes a length that is longer than the length of the eccentric crown 28A attached to the drive shaft 20. In this illustrative example, no distal resistance element or spring 200D is attached. The proximal spring 200P may include a length at least more than twice the length of the eccentric crown 28A, and as shown in fig. 11, may include a length 5 times or more the length of the eccentric crown 28A. The resistance element shown as spring 200P may also take the form of a coiled wire mass or other similar structure.

Working example 2

As seen in fig. 11, in contrast to the drive shaft 20 that includes only the eccentric crown 28A (unmodified device), the proximal spring 200P is placed on the drive shaft 20 proximal to and spaced apart from the eccentric crown 28A (modified device).

The results of working example 2 are shown in graphical form in fig. 12.

The unmodified device achieves a very low orbit frequency (about 20Hz) with a very slow, low growth rate at a rotational speed of about 700Hz, and a maximum orbit frequency of about 90Hz at a rotational speed of about 1850 Hz.

On the other hand, the modified device reached a winding frequency slightly higher than 50Hz at the lowest rotational speed of about 700Hz and showed a certain higher growth rate on the winding frequency than the unmodified device. The modified device reaches a winding frequency slightly above 200Hz at a rotational speed of about 1850 Hz.

As can be seen, the addition of proximal resistance element 200P increases the orbit frequency at any given rotational speed and causes a lower rotational speed of orbital motion than the unmodified device.

Coiled wire or wire mass element attached to a drive shaft without an eccentric crown

The coiled wire or wire coil or spring resistance element may be partially wound around the drive shaft 20 and/or may include an eccentric or asymmetric radial mass distribution as described above to provide the necessary eccentricity by moving the local center of mass C radially away from the axis of rotation and to enable orbital motion during high speed spinning. In either case, the material of the resistance element may preferably be a dense material such as tungsten, i.e. denser than the material of the drive shaft, which may be stainless steel. Alternatively, a medium density material, such as stainless steel, or even a relatively low density material, such as titanium (less dense than the material of the drive shaft) may be used. In this embodiment, at least some of the exterior surfaces of the wires or filaments of the resistance element and/or the wire turns or wires 41 of the drive shaft may be coated with an abrasive material.

In other embodiments, the addition of mass to the resistance elements and the increased outer diameter will be sufficient to cause orbital motion, particularly when the resistance elements are longitudinally spaced apart.

Braided mass elements disposed on a drive shaft having an eccentric crown

Another resistance element including a mass may include a braided structure at least partially wrapped around the drive shaft proximal and/or distal to the eccentric crown. As with the spring 200 embodiment, the braided resistance element may be concentric and have a center of mass on the rotational axis of the drive shaft, or may be eccentric and include an asymmetric mass may be introduced by an eccentric or asymmetric radial mass distribution in the braided element or by partial wrapping of the drive shaft 20.

Braided mass elements disposed on a drive shaft without an eccentric crown

The woven mass resistance element may be partially wrapped around the drive shaft 20 to provide the necessary eccentricity by moving the local center of mass C radially away from the axis of rotation and to be able to cause orbital motion during high speed spin selection, as described above. In this case, an eccentric abrasive element or crown 28A, for example, may not be required. In this embodiment, at least some of the outer surfaces of the wire turns or wires 41 of the braided body of the braided mass element and/or the drive shaft may be coated with an abrasive material.

As noted above, in certain embodiments, the addition of mass to the braided mass resistance elements and the increased outer diameter will be sufficient to cause orbital motion, particularly when more than one braided resistance element is provided and the braided resistance elements are longitudinally spaced.

For the reasons described herein, this and all embodiments discussed herein may cause the drive shaft 20 to orbit if desired or with the aid of an eccentric grinding element (such as eccentric crown 28A).

Ball arranged on a drive shaft with an eccentric crown

Alternatively, as shown in fig. 13, one or more balls may be attached to the drive shaft proximal and distal to the exemplary eccentric abrasive element (eccentric crown 28A). The ball adjacent to crown 28A may be in touching contact with crown 28A or may be spaced from crown 28A. When more than one ball is disposed proximal and/or distal to the crown 28A, adjacent balls may touch or may be spaced apart. Adjacent beads are not fixed to each other, thereby maintaining flexibility. The number of balls proximal to the eccentric crown 28A may be equal to or may be different from the number of balls distal to the eccentric crown 28A. As shown, equal mass beads are used, although unequal mass beads may also be used. Further, in fig. 13, 6 proximal and 5 distal beads are shown, wherein all of the beads have equal mass, so that the overall distal mass of all distal beads is greater than the overall proximal mass of all proximal beads.

Ball arranged on a drive shaft without an eccentric crown

Similar to the other embodiments described above, the proximal and/or distal balls may be eccentric (by mass or mounting or geometric configuration), or concentric, and accordingly create a center of mass located away from or on the axis of rotation of the drive shaft. In either case, the drive shaft 20 may be caused to orbit without the need for or with the aid of an eccentric abrasive element, such as the exemplary crown 28A, for the reasons described herein.

As with the other resistance elements discussed herein, the ball may be non-rotatably or rotatably operatively attached to the drive shaft. The beads may be spherical or non-concentric in geometry.

Low profile girdle for placement on a drive shaft with/without eccentric crown

Fig. 14 shows a modification to fig. 13 in which a ring is used instead of a ball. All other features, alternatives and functions described in connection with fig. 13 apply to the modified collar of fig. 14.

Articulated hydrofoil for increasing the coefficient of resistance of a rotating drive shaft and having a delivery configuration and a working configuration

Finally, fig. 15A and 15B illustrate another application of the fluid dynamic principle for forcing a rotating grinding element attached to a rotating drive shaft to spin off concentric rotation and drive the grinding element into orbital motion, wherein the working diameter depicted during high speed rotation is larger than its resting diameter. Thus, fig. 15 shows a hydrofoil abrasive element that, when attached to the drive shaft 20 and rotated at a threshold rotational speed, will induce orbital motion. The maximum diameter of the hydrofoil abrasive element can be reduced for delivery through a sheath or delivery catheter and to accommodate smaller and/or tortuous vessels by providing a point of inflection (e.g., a hinge as shown, allowing the hydrofoil extension to fold around the body of the hydrofoil abrasive element). Once delivered out of the delivery catheter or sheath lumen, the foil extension element may be caused to expand by rotating the drive shaft in a first rotational direction. Once the hydrofoil extension is expanded by the force of the fluid and rotated in the fluid and secured to the operating position, the drive shaft may be rotated in a second opposite rotational direction, wherein the fluid dynamics cause orbital motion. Alternatively, the foil extension hinge may be biased to expand to the operative position.

Alternatively, the hydrofoil extension may comprise a shape memory material that is biased to expand to an operative position such that the hydrofoil extension may be retracted within the lumen of the delivery catheter or sheath for delivery in a low profile, and then upon delivery out of the lumen of the catheter or sheath, the hydrofoil extension will be biased to expand to allow rotation and cause orbital motion. The hydrofoil extension may be re-retracted for withdrawal by moving the hydrofoil abrasive element proximally into the catheter or sheath lumen.

The description of the embodiments set forth herein and their applications are to be understood as illustrative, and not as limiting the scope of the disclosure. The features of the various embodiments may be combined with other embodiments and/or features thereof within the metes and bounds of the disclosure. Variations and modifications of the embodiments disclosed herein are possible in light of the present disclosure, and practical alternatives to and equivalents of the various elements of the embodiments will be understood and become apparent to those of ordinary skill in the art upon study of the present disclosure. Such changes and modifications may be made to the embodiments disclosed herein without departing from the scope and spirit of the present invention. Accordingly, all alternatives, variations, modifications, and the like as may occur to those of ordinary skill in the art are deemed to be within the metes and bounds of the disclosure.