阅读说明：本技术 带金属内层和聚合物护套的驱动轴 (Drive shaft with metal inner layer and polymer jacket ) 是由 P·L·格罗特 M·D·坎布朗恩 J·P·希金斯 J·R·斯通 于 2020-03-05 设计创作，主要内容包括：本发明公开了包括用于高速旋转医疗手术(例如,动脉粥样硬化切除)的驱动轴的装置和系统的各种实施例。一般地,驱动轴被配置成用于传递扭矩并启动与其附接的工具(例如研磨头)的旋转,并且被聚合物护套覆盖。在某些实施例中,允许聚合物护套响应于驱动轴的旋转而旋转,使得聚合物护套在其近端处不固定。驱动轴的各种实施例可以包含近侧和/或远侧止动件,在包括近侧和远侧止动件的实施例中,该近侧和/或远侧止动件能够使聚合物护套在止动件之间纵向运动,或在仅包含远侧止动件的实施例中,纵向运动至远侧止动件。除了或代替聚合物护套,本公开描述的装置和系统的各种实施例可任选地包含驱动轴内的金属内衬。(Various embodiments of devices and systems including drive shafts for high-speed rotational medical procedures (e.g., atherectomy) are disclosed. Generally, the drive shaft is configured to transmit torque and initiate rotation of a tool (e.g., a grinding bit) attached thereto, and is covered by a polymer jacket. In certain embodiments, the polymer sheath is allowed to rotate in response to rotation of the drive shaft such that the polymer sheath is not fixed at its proximal end. Various embodiments of the drive shaft may incorporate proximal and/or distal stops that enable the polymer sheath to move longitudinally between the stops in embodiments that include proximal and distal stops, or to the distal stop in embodiments that only incorporate a distal stop. Various embodiments of the devices and systems described in the present disclosure may optionally include a metal liner within the drive shaft in addition to or in place of the polymer jacket.)

1. A medical device, comprising:

a rotary drive shaft; and

a polymer jacket partially surrounding the rotary drive shaft,

wherein the polymer jacket does not rotate in response to rotation of the rotating drive shaft, and wherein the polymer jacket is fixed in a longitudinal position.

2. The medical device of claim 1, further comprising a flexible metal liner within a lumen defined by the rotary drive shaft.

3. The medical device of claim 2, further comprising the flexible metal liner being rotationally and longitudinally fixed in position.

4. The medical device of claim 2, further comprising the flexible metal liner adapted for rotation and/or longitudinal movement independent of the drive shaft.

5. The medical device of claim 4, wherein the flexible metal liner is adapted for longitudinal movement independent of the drive shaft, wherein the drive shaft includes an inner distal stop extending from an inner surface of a distal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the inner distal stop limits longitudinal movement of the flexible metal liner distally to the inner distal stop.

6. The medical device of claim 5, wherein the drive shaft further includes an internal proximal stop extending from an inner surface of a proximal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the internal proximal stop and the internal distal stop limit longitudinal movement of the flexible metal liner between the internal proximal stop and the internal distal stop.

7. A medical device, comprising:

a rotary drive shaft; and

a polymer jacket partially surrounding the rotary drive shaft,

wherein the polymer jacket is configured to rotate and/or move longitudinally independently of the drive shaft in response to rotation of the drive shaft.

8. The medical device of claim 7, further comprising a flexible metal liner within the lumen of the rotary drive shaft.

9. The medical device of claim 8, further comprising the flexible metal liner rotationally and longitudinally fixed in position.

10. The medical device of claim 8, further comprising the flexible metal liner adapted for rotation and/or longitudinal movement independent of the drive shaft.

11. The medical device of claim 8, further comprising the flexible metal liner adapted to rotate and/or move longitudinally independently of the drive shaft and the polymer sheath.

12. The medical device of claim 11, wherein the flexible metal liner is adapted for longitudinal movement independent of the drive shaft, wherein the drive shaft includes an inner distal stop extending from an inner surface of a distal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the inner distal stop limits longitudinal movement of the flexible metal liner distally to the inner distal stop.

13. The medical device of claim 12, wherein the drive shaft further includes an internal proximal stop extending from an inner surface of a proximal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the internal proximal stop and the internal distal stop limit longitudinal movement of the flexible metal liner between the internal proximal stop and the internal distal stop.

14. The medical device of claim 7, wherein the polymer sheath is adapted to move longitudinally independently of the drive shaft, wherein the drive shaft includes an outer distal stop extending radially outward from an outer surface of a distal portion of the drive shaft, and wherein the outer distal stop limits longitudinal movement of the polymer sheath distally to the outer distal stop.

15. The medical device of claim 14, wherein the drive shaft further includes an outer proximal stop extending radially outward from an outer surface of the proximal portion of the drive shaft, and wherein the outer proximal stop and the outer distal stop limit longitudinal movement of the polymeric sheath between the outer proximal stop and the outer distal stop.

16. A rotational atherectomy device, comprising:

a prime mover having a prime mover drive shaft operably connected thereto;

a rotary drive shaft;

a grinding head disposed on the rotary drive shaft; and

a polymer sheath partially surrounding the rotary drive shaft, wherein a distal end of the polymer sheath is proximal to the abrading head,

wherein the polymer jacket is configured to rotate and/or move longitudinally independently of the drive shaft in response to rotation of the drive shaft.

17. The rotational atherectomy device of claim 16, further comprising a flexible metal liner within the lumen of the rotational drive shaft.

18. The rotational atherectomy device of claim 17, further comprising the flexible metal liner being rotationally and longitudinally fixed in position.

19. The rotational atherectomy device of claim 17, further comprising a flexible metal liner adapted to rotate and/or move longitudinally independently of the drive shaft.

20. The rotational atherectomy device of claim 17, further comprising a flexible metal liner adapted to rotate and/or move longitudinally independently of the drive shaft and the polymer sheath.

21. The rotary atherectomy device of claim 20, wherein the flexible metal liner is adapted to move longitudinally independently of the drive shaft, wherein the drive shaft includes an inner distal stop extending from an inner surface of a distal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the inner distal stop limits longitudinal movement of the flexible metal liner distally to the inner distal stop.

22. The rotational atherectomy device of claim 21, wherein the drive shaft further comprises an inner proximal stop extending from an inner surface of a proximal portion of the drive shaft into the lumen defined by the drive shaft, and wherein the inner proximal stop and the inner distal stop limit longitudinal movement of the flexible metal liner between the inner proximal stop and the inner distal stop.

23. The rotational atherectomy device of claim 16, wherein the polymer sheath is adapted to move longitudinally independently of the drive shaft, wherein the drive shaft includes an outer distal stop extending radially outward from an outer surface of the distal portion of the drive shaft, and wherein the outer distal stop limits longitudinal movement of the polymer sheath distally to the outer distal stop.

24. The rotational atherectomy device of claim 23, wherein the drive shaft further comprises an outer proximal stop extending radially outward from an outer surface of the proximal portion of the drive shaft, and wherein the outer proximal stop and the outer distal stop limit longitudinal movement of the polymeric sheath between the outer proximal stop and the outer distal stop.

Technical Field

The present disclosure relates to drive shafts used in medical device surgery. And more particularly to a drive shaft for use in rotary atherectomy and thrombectomy procedures.

Background

Various techniques and instruments have been developed for removing or repairing tissue in arteries and similar body passageways. A common goal of such techniques and instruments is to remove atherosclerotic plaque in a patient's artery. Atherosclerosis is characterized by the accumulation of fatty deposits (atheroma) in the intimal layer (endothelium) of a patient's blood vessels. Typically, atherosclerotic material initially deposited as relatively soft, cholesterol-rich material hardens into calcified atherosclerotic plaques over time. This atheroma restricts blood flow and is therefore often referred to as a stenotic lesion or stenosis, and the obstructive material is referred to as stenotic material. These stenoses, if left untreated, can lead to angina, hypertension, myocardial infarction, stroke, and the like.

Rotational atherectomy has become a common technique for removing such stenotic material. This procedure is most often used to initiate the opening of calcified lesions in coronary arteries. In most cases, rotational atherectomy is not used alone, but is followed by balloon angioplasty, and instead, stents are subsequently placed very frequently to help maintain patency of the open artery. For non-calcified lesions, balloon angioplasty procedures alone are most often used to open the artery, and a stent is typically placed to maintain the patency of the open artery. However, studies have shown that a significant proportion of patients undergoing balloon angioplasty and having a stent placed in an artery experience stent restenosis, most often due to the development of a blockage of the stent over time due to the overgrowth of scar tissue within the stent. In this case, atherectomy is the preferred method of removing excess scar tissue from the stent (balloon angioplasty is not very effective within the stent), thereby restoring patency to the artery.

Various rotational atherectomy devices have been developed in an attempt to remove stenotic material. Such devices typically include a drive shaft on which the abrading head is disposed, and a handle that includes a rotary drive mechanism and is coupled to a proximal portion of the drive shaft. Known drive shafts for use with rotary atherectomy devices typically include a wire wrap, typically a stainless steel metal structure, and may be covered by a polymer coating or sheath that is longitudinally fixed relative to the drive shaft. The polymer coating or polymer jacket helps contain the fluid within and/or around the drive shaft during rotation and, to some extent, helps the drive shaft maintain a working diameter as close as possible to its resting diameter during rotation of the drive shaft. The polymer coating will rotate with the drive shaft while the polymer jacket will typically not rotate. In other words, in an atherectomy device comprising a polymer sheath covering the drive shaft, the drive shaft may rotate within the polymer sheath while the polymer sheath remains stationary relative to the handle.

Although a polymer jacket longitudinally fixed in place in such known systems may help the rotating drive shaft maintain a diameter near its resting diameter during high speed rotation as compared to a system that does not include a polymer jacket, applicants have discovered that such known polymer jackets can be improved. For example, known fixed position polymer jackets may not adequately mitigate radial misalignment of the drive shaft and other problems that may arise during high speed rotation of the drive shaft, such as undesirable vibrations and/or standing waves in the drive shaft during high speed rotation. Radial deflection of the drive shaft during high speed rotation, unwanted vibrations, and/or standing waves in the drive shaft may deflect the abrading head from its intended path of travel, which in turn may reduce the efficiency of the abrading head in removing occlusive material and/or cause complications from uncontrolled contact of the abrading head with the vessel wall.

Accordingly, a rotary medical device (e.g., a rotary atherectomy device) comprising a drive shaft and a polymer sheath to address these issues is desired. Such a device would provide improved performance over known rotational medical devices by, for example, increasing the efficiency of rotational surgery and reducing the associated risk of complications. Further, in some embodiments, applicants have discovered that a smooth metallic inner layer can be used to provide improved performance of the rotating medical device.

Various embodiments of the present invention address these problems, among others. It should be noted that these problems may arise in devices configured for rotational surgery other than atherectomy, where these problems are likewise addressed by various embodiments of the present invention.

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

U.S. Pat. No. 9,468,457, "ATHERECTOMY device with eccentric CROWN (ATHERECTOMY DEVICE WITH ECCENTRIC CROWN)";

U.S. Pat. No. 9,439,674, "Rotary ATHERECTOMY device with EXCHANGEABLE drive shaft and meshing gears (ROTATONAL ATHERECTOMY DEVICE WITH EXCHANGEABLE DRIVE SHAFT AND MESHING GEARS)";

U.S. Pat. No. 9,220,529, "rotating ATHERECTOMY device with Motor (ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR)";

U.S. Pat. No. 9,119,661, "rotating ATHERECTOMY device with Motor (ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR)";

U.S. Pat. No. 9,119,660, "rotating ATHERECTOMY device with Motor (ROTATONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR)";

U.S. Pat. No. 9,078,692, "ROTATIONAL ATHERECTOMY System (ROTATONAL ATHERECTOMY SYSTEM)";

U.S. Pat. No. 6,295,712, "ROTATIONAL ATHERECTOMY DEVICE (ROTATONAL ATHERECTOMY DEVICE)";

U.S. Pat. No. 6,494,890, "eccentric rotating atherectomy device (ECCENTRIC ROTATIONAL ATHERECTOMY DEVICE)";

U.S. Pat. No. 6,132,444, "eccentric drive shaft FOR ATHERECTOMY device and METHOD of MANUFACTURE (ECCENTRIC DRIVE SHAFT FOR ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE)";

U.S. Pat. No. 6,638,288, "eccentric drive shaft FOR ATHERECTOMY device and METHOD of MANUFACTURE (ECCENTRIC DRIVE SHAFT FOR Atherrectomy DEVICE AND METHOD FOR manual)";

U.S. Pat. No. 5,314,438, "grinding drive shaft device FOR ROTATIONAL ATHERECTOMY" (ABRASIVE DRIVE SHAFT DEVICE FOR ROTATIONAL ATHERECTOMY) ";

U.S. Pat. No. 6,217,595, "ROTATIONAL ATHERECTOMY DEVICE (ROTATONAL ATHERECTOMY DEVICE)";

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

U.S. Pat. No. 7,507,245, "ROTATIONAL atherectomy device with ABRASIVE CROWN (ROTATINAL ANGIOPLASTY DEVICE WITH ABRASIVE CROWN)";

U.S. patent No. 6,129,734, "rotary ATHERECTOMY device with radially EXPANDABLE PRIME MOVER COUPLING (rotanal ATHERECTOMY DEVICE WITH RADIALLY ex pandable PRIME MOVER coating)";

U.S. patent application No. 11/761,128, "eccentric abrading head for high SPEED ROTATIONAL ATHERECTOMY DEVICES (ECCENTRIC ABRADING HEAD FOR HIGH-SPEED rotation ATHERECTOMY DEVICES)";

U.S. patent application No. 11/767,725, "SYSTEM, device AND METHOD FOR OPENING AN occlusive LESION" (SYSTEM, APPARATUS AND METHOD FOR occluding AN optically affected LESION) ";

U.S. patent application No. 12/130,083, "eccentric abrasive elements for high SPEED ROTATIONAL ATHERECTOMY DEVICES (ECCENTRIC ABRADING ELEMENT FOR HIGH-SPEED rotation ATHERECTOMY DEVICES)";

U.S. patent application No. 12/363,914, "MULTI-MATERIAL ABRADING HEAD FOR ATHERECTOMY device with lateral center OF MASS (MULTI-MATERIAL ABRADING HEAD FOR ATHERECTOMY device DEVICES HAVING LATERALLY DISPLACED CENTER OF MASS)";

U.S. patent application No. 12/578,222, "rotary ATHERECTOMY device with pre-CURVED drive shaft (rotatinonal ATHERECTOMY DEVICE WITH PRE-CURVED DRIVE SHAFT)";

U.S. patent application No. 12/130,024, "eccentric abrading and cutting head for high SPEED ROTATIONAL ATHERECTOMY DEVICES (ECCENTRIC ABRADING AND CUTTING HEAD FOR HIGH-SPEED rotation ATHERECTOMY DEVICES)";

U.S. patent application No. 12/580,590, "eccentric abrading and cutting head for high SPEED ROTATIONAL ATHERECTOMY DEVICES (ECCENTRIC ABRADING AND CUTTING HEAD FOR HIGH-SPEED rotation ATHERECTOMY DEVICES)";

U.S. patent application No. 29/298,320, "rotaspecific ATHERECTOMY abrading CROWN (rotatypical ablative CROWN)";

U.S. patent application No. 29/297,122, "rotaspecific ATHERECTOMY abrading CROWN (rotatypical ablative CROWN)";

U.S. patent application No. 12/466,130, "BIDIRECTIONAL EXPANDABLE HEAD FOR rotating ATHERECTOMY DEVICE (BIDIRECTIONAL EXPANDABLE HEAD FOR rotating DEVICE)"; and

U.S. patent application No. 12/388,703, "rotating ATHERECTOMY dissecting ABRADING HEAD AND METHOD for increasing ABRADING EFFICIENCY" (ROTATONAL (R) ATHERECTOMY SEGMENTED ABRADING HEAD AND METHOD TO IMPROVE ABRADING EFFICIENCY) ".

Disclosure of Invention

Various embodiments are disclosed that include a drive shaft for use in high-speed rotational medical procedures (e.g., atherectomy). Generally, the drive shaft is configured to transmit torque and initiate rotation of a tool, such as a grinding element (also referred to herein as a "grinding bit"), attached thereto and covered by a polymer jacket. In certain embodiments, the polymeric sheath is not fixed at its proximal end, thus allowing it to rotate in response to rotation of the drive shaft. Various embodiments of the drive shaft may incorporate proximal and/or distal external stops that enable the polymer sheath to move longitudinally between the stops in embodiments that include proximal and distal external stops, or to the distal external stop in embodiments that include only a distal stop. Various embodiments of the devices and systems discussed herein may optionally include a metal liner within the drive shaft in addition to or in place of the polymer jacket. In certain embodiments, the metal liner is not fixed at its proximal end, thus allowing rotation in response to rotation of the drive shaft. Some embodiments that include a metal liner may also include proximal and/or distal internal stops that enable longitudinal movement of the metal liner therebetween in embodiments that include proximal and distal internal stops, or to the distal stop in embodiments that include only a distal stop.

Embodiments of the present invention may address the problems associated with known rotary devices by providing a rotatable, longitudinally movable polymer jacket about a drive shaft that minimizes unwanted radial deflection of the drive shaft and suppresses vibration as compared to the fixed polymer jacket of known rotary devices. Additionally, or alternatively, features of embodiments of the present invention may better reduce or eliminate unwanted vibrations and/or standing waves in the drive shaft during high speed rotation as compared to the fixed polymer jackets of known rotating devices.

One embodiment is a medical device comprising: a rotary drive shaft; and a polymer jacket partially surrounding the rotating drive shaft, wherein the polymer jacket does not rotate in response to rotation of the rotating drive shaft, and wherein the polymer jacket is fixed in a longitudinal position.

Another embodiment is a medical device comprising: a rotary drive shaft; and a polymer jacket partially surrounding the rotating drive shaft, wherein the polymer jacket is configured to rotate and/or move longitudinally independent of the drive shaft in response to rotation of the drive shaft.

Another embodiment is a rotational atherectomy device comprising: a prime mover having a prime mover drive shaft operably connected thereto; a rotary drive shaft; the system includes a rotatable drive shaft, a polymeric sheath disposed on the rotatable drive shaft, and a polymeric sheath partially surrounding the rotatable drive shaft, wherein a distal end of the polymeric sheath is proximal to the abrading head, wherein the polymeric sheath is configured to rotate and/or move longitudinally independent of the drive shaft in response to rotation of the drive shaft.

The description of the invention and its applications as set forth herein are illustrative and are not intended to limit the scope of the invention. The features of the various embodiments may be combined with other embodiments within the concept of the invention. Variations and modifications of the embodiments disclosed herein are possible, and practical alternatives to and equivalents of the various elements of the embodiments will be understood by those skilled in the art upon study of this patent document. These and other changes and modifications may be made to the embodiments disclosed herein without departing from the scope and spirit of the present invention.

Drawings

FIG. 1 is a perspective view of one embodiment of a known rotational atherectomy device and system;

FIG. 2 is a partial schematic view and partial longitudinal cross-sectional view of one known embodiment of a rotary medical device and system, the cross-section being generally parallel to a longitudinal axis A;

FIG. 3 is a longitudinal cross-sectional view of one embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis A;

FIG. 4 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis A;

FIG. 5 is an axial cross-sectional view of the embodiment of FIGS. 3 and 4, the cross-section being generally perpendicular to the longitudinal axis A;

FIG. 6 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis A;

FIG. 7 is an axial cross-sectional view of the embodiment of FIG. 6, the cross-section being generally perpendicular to the longitudinal axis A;

FIG. 8 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis A; and

fig. 9 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis a.

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. It should also be understood that while one or more embodiments described herein are described or illustrated as including each of a proximal stop, a distal stop, and a metal liner, embodiments including less than all of these features are also contemplated and are within the scope of the present disclosure.

Figures 1-9 show various embodiments of known devices and devices of the present invention. Although the embodiments are shown separately, one skilled in the art will appreciate that aspects of one or more of the illustrated embodiments may be combined.

FIG. 1 illustrates one known embodiment of a rotational atherectomy device that may incorporate the present invention. The device comprises a handle portion 10, an elongated flexible drive shaft 20 having an enlarged abrading head 28, and an elongated catheter 13 extending distally from the handle portion 10. The drive shaft 20 is comprised of helical coils as is known in the art and the grinding bit 28 is fixedly attached thereto. Known drive shafts, such as drive shaft 20, are made of multi-wound coils, wherein the coils may comprise any suitable metallic material. The inherent structure of the known coil allows for spaces to be left between the wires. These spaces allow fluid, such as saline and/or water or other fluid, to pass through the inner diameter of the drive shaft coil to provide a cooling and/or lubricating effect to the interface of the drive shaft coil and the guidewire 15.

Generally, in known constructions, a coupling (typically comprising a seamless metal tube) is attached to the proximal end of the coil drive shaft and the drive shaft of the handle portion 10, wherein the drive shaft of the handle portion 10 is driven by a prime mover, thereby providing a connection between the prime mover (e.g., a turbine or an electric motor) and the drive shaft 20. However, other suitable drive shaft configurations may be used within the scope of compatibility with embodiments of the present invention without departing from the scope and spirit of the present invention.

With continued reference to figure 1, the catheter 13 has an inner lumen in which most of the length of the drive shaft 20 is disposed, except for the enlarged abrading head 28 and a short segment distal to the abrading head 28. The drive shaft 20 also defines a lumen that allows the drive shaft 20 to be advanced and rotated over the guidewire 15. A fluid supply tube 17 may be provided for introducing a cooling and lubricating solution (typically saline or another biocompatible fluid) into the catheter 13.

The handle portion 10 desirably houses a turbine (or similar rotational drive mechanism) for rotating the drive shaft 20 at high speed. Handle portion 10 may generally be connected to a power source, such as compressed air delivered through tube 16. A pair of optical cables 25 may also be provided, alternatively one optical cable may be used for monitoring the rotational speed of the turbine and drive shaft 20. Handle portion 10 also desirably includes a control knob 11 for advancing and retracting the turbine and drive shaft 20 relative to the catheter 13 and the body of handle portion 10.

FIG. 2 is a partial schematic view and a partial longitudinal cross-sectional view of one known embodiment of a rotating medical device, the cross-section being generally parallel to the longitudinal axis A. It should be noted that any one or more of the features, functions, and advantages described herein with respect to the rotational medical device of fig. 1 may optionally be included in the rotational medical device of fig. 2, and vice versa. It should also be noted that like reference numerals refer to generally similar features in the rotating medical devices of fig. 1 and 2. For example, the drive shaft 20 is generally the same in the rotating medical devices of fig. 1 and 2.

The rotary medical device shown in fig. 2 includes a drive shaft 20, the drive shaft 20 including a wire or wire coil operatively connected to a prime mover 30, such as a turbine, pneumatic device, or electric motor. The reservoir 32 is operatively and fluidly connected to the system and provides an outer polymer jacket 22 fixed at a longitudinal location at the proximal end of the drive shaft 20 and extending distally to the distal end of the turns of the drive shaft 20, wherein the polymer jacket 22 and the turns of the drive shaft 20 typically terminate at the same location. That is, in the embodiment of fig. 2, the polymer jacket 22 covers the entirety of the drive shaft 20. The drive shaft 20 is independent of the polymer jacket 22 and rotates therein. Generally, the polymer jacket 22 helps contain fluid within and/or around the drive shaft 20 during rotation and further helps the drive shaft 20 maintain a working diameter as close as possible to its resting diameter. In other words, the polymer jacket 22 helps minimize unwanted radial excursions through the compliant turns of the drive shaft 20, keeping the drive shaft 20 as aligned as possible with the stationary nominal axis of rotation a.

Fig. 3 is a longitudinal cross-sectional view of one embodiment of the invention, the cross-section being generally parallel to the longitudinal axis a. In FIG. 3, the prime mover 30 and reservoir 32 components shown in FIG. 2 have been omitted, but may be considered part of the system of FIG. 3. A drive shaft 40 comprising a wire turn is provided, partially covered by an outer polymeric sheath 42, which is fixed at its proximal end. One or more features of the drive shaft 40 and the polymeric jacket 42 may be substantially similar to corresponding features of the drive shaft 20 and the polymeric jacket 22 of the embodiment of fig. 2, such as the turns of the drive shaft 20 and/or the composition of the materials forming the drive shaft 20 and the polymeric jacket 22. The polymer jacket 42 does not rotate, and thus the drive shaft 40 independently rotates within the polymer jacket 42. The embodiment of fig. 3 differs from the embodiment of fig. 2 in that the distal section 46 of the drive shaft 40 is exposed and not covered by the polymer jacket 42. The distal section 46 may include a tool, such as a rotational burr; such as a grinding bit (not shown), or other tool.

Alternatively, the polymer sheath 42 may not be fixed at its proximal end. In this alternative embodiment of fig. 3, the polymer jacket 42 is allowed to rotate in response to rotation of the drive shaft 40, but the polymer jacket 42 and the drive shaft 40 themselves are not connected. Drive shaft 40 may include a proximal atraumatic stop 48P and a distal atraumatic stop 48D, which may include smooth atraumatic ridges over the outer surface of drive shaft 40. The polymer jacket 42 is thus longitudinally constrained between the stops 48P and 48D, which may prevent any longitudinal movement of the polymer jacket 42 or may allow some longitudinal movement, depending on the distance between the stops 48P and 48D relative to the length of the polymer jacket 42. More alternatively, only distal stop 48D may be provided, wherein polymer sheath 42 is free to move distally to distal stop 48D. More alternatively, proximal stop 48P and/or distal stop 48D may each include more than one protuberance, with a plurality of proximal protuberances and/or a plurality of distal protuberances radially spaced from one another about the circumference of a respective proximal or distal segment of drive shaft 40. In all cases of the present embodiment, the polymer jacket 42 is free to rotate during rotation of the drive shaft 40, but need not rotate at the same speed as the drive shaft 40.

This arrangement of polymer sheath 42 free to rotate during rotation of drive shaft 40, discussed above, helps maintain the outer diameter of drive shaft 40 at a working diameter near its resting diameter during rotation, adding a further resonance reduction or mitigation feature when polymer sheath 42 is properly positioned between proximal stop 48P and distal stop 48D with or without longitudinal movement of polymer sheath 42 therebetween. For example, allowing the polymer sheath 42 to translate and rotate longitudinally between the proximal stop 48P and the distal stop 48D is allowing the polymer sheath 42 to translate and/or rotate longitudinally to help reduce any unwanted vibration and/or standing wave problems that may occur during high speed rotation of the drive shaft 40. That is, allowing polymer sheath 42 to translate and rotate longitudinally between proximal stop 48P and distal stop 48D is allowing polymer sheath 42 to rotate and/or slide to a natural position to help minimize or eliminate these potential problems.

In addition to the advantages described above, the arrangement of FIG. 3 provides additional stability and support for a guidewire (not shown, but well known to those skilled in the art; e.g., guidewire 15 shown in FIG. 1) that may extend through the lumen of drive shaft 40. It is well known that vibrations and other forces, in addition to the drive shaft, may adversely affect the guidewire, particularly at its distal end. The polymer jacket 42 also serves to dampen vibrations and other forces applied to the guidewire in known devices while dampening radial deflection of the drive shaft 40.

Fig. 4 is a longitudinal cross-sectional view of another embodiment of the invention, the cross-section being generally parallel to the longitudinal axis a. In particular, the embodiment of fig. 4 is a variation of the embodiment of fig. 3. A drive shaft 50 comprising wire turns and proximal and distal stops 58P, 58D is provided and partially covered by a polymer jacket 52, leaving proximal and distal sections 54, 56 of the drive shaft 50 exposed. One or more features and advantages of drive shaft 50, proximal and distal stops 58P, 58D, and polymer sheath 52 may be substantially similar to the corresponding features and advantages of drive shaft 40, stops 48P and 48D, and polymer sheath 42 in the embodiment of fig. 3. Fig. 4 shows proximal stop 58P and distal stop 58D spaced apart by a distance greater than the longitudinal length of polymer sheath 52, thereby allowing polymer sheath 52 to move a predetermined length of longitudinal travel in response to rotation and associated radial movement of drive shaft 50, thereby providing drive shaft 50 and the same benefits discussed above for the guidewire.

Fig. 5 is an axial cross-sectional view of the embodiment of fig. 3 and 4, the cross-section being generally perpendicular to the longitudinal axis a. As shown in fig. 5, an outer polymer jacket 52 surrounds the inner turns of the drive shaft 50. A small circumferential space (not shown) may be defined between the drive shaft 50 and the polymer jacket 52, which may enable independent rotation of the drive shaft 50 and the polymer jacket 52.

Fig. 6-9 illustrate various embodiments of the rotational medical device of the present invention, wherein the rotational medical device comprises a smooth metal liner within a drive shaft. As described below, the metal liner may be used with or without a polymer jacket. When used with a polymer jacket, the polymer jacket and metal liner may optionally be longitudinally fixed and not connected to the drive shaft so that neither the polymer jacket nor the metal liner rotates, or may be configured so that one or both of the polymer jacket and the metal liner rotate independently of the drive shaft.

Fig. 6 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis a. A drive shaft 60 comprising a wire turn is provided and the drive shaft 60 is partially covered by a polymeric sheath 62 such that a distal section 66 and a proximal section 67 of the drive shaft 60 are exposed. Drive shaft 60 includes a proximal stop 68P and a distal stop 68D. One or more features and advantages of the drive shaft 60, stops 68P and 68D, and polymer jacket 62 may be substantially similar to the corresponding features and advantages of the drive shaft, stops, and polymer jacket of the embodiment of fig. 3-5. The embodiment of fig. 6 adds a smooth metal liner 64 within the turns of the drive shaft 60 to the embodiment of fig. 4 and 5.

The smooth metal liner 64 is flexible and not attached to the drive shaft 60. As shown in fig. 6, drive shaft 60 further includes an inner proximal stop 70P and an inner distal stop 70D. Alternatively, the internal stop of the drive shaft 60 may comprise only the distal internal stop 70D. The internal stops 70P and 70D comprise ridges that extend radially inward from the inner surface of the drive shaft 60 into the internal cavity defined by the drive shaft 60. In some cases, inner proximal stop 70P and/or inner distal stop 70D may each include one or more protuberances, a plurality of proximal protuberances and/or a plurality of distal protuberances radially spaced from one another about an inner circumference of the respective proximal or distal section 67, 66 of drive shaft 60. In any such case, the metal liner 64 is free to move within the drive shaft 60 between the inner proximal stop 70P and/or the inner distal stop 70D, or between the proximal end of the drive shaft 60 and the inner distal stop 70D, in a manner similar to that described above in connection with the polymer sheath and drive shaft of the embodiment of fig. 3-5. Thus, the metal liner 64 is allowed to move longitudinally within a predetermined distance. If proximal stopper 70P and distal stopper 70D are used, the distance between proximal stopper 70P and distal stopper 70D may be greater than, or equal to, the length of metal liner 64 to define the desired longitudinal stroke length of metal liner 64.

The metal liner 64 will help prevent fluid flow into/out of the lumen defined by the drive shaft 60 and will also provide the advantages of the rotatable/longitudinally translatable polymer jacket related to those discussed above with respect to resonance, vibration, etc., thereby helping to maintain the integrity of the drive shaft 60 and the guidewire that will translate within the metal liner 64 and/or rotate relative to the metal liner 64. In some embodiments, the stiffness of the metal liner 64 may be different (e.g., greater) than the stiffness of the polymer jacket 62 and/or other polymer jackets discussed above in order to provide a desired degree of flexibility to a device containing the metal liner 64.

Fig. 7 is an axial cross-sectional view of the embodiment of fig. 6, the cross-section being generally perpendicular to the longitudinal axis a. As shown in fig. 7, an outer polymer jacket 62 surrounds the inner turns of the drive shaft 60. A small circumferential space (not shown) may be defined between the metal liner 64 and the drive shaft 60, which may enable independent rotation of the drive shaft 60 and the metal liner 64. A small circumferential space (not shown) may be defined between the drive shaft 60 and the polymer jacket 62, which may enable independent rotation of the drive shaft 60 and the polymer jacket 62.

Fig. 8 is a longitudinal cross-sectional view of another embodiment of the invention, the cross-section being generally parallel to the longitudinal axis a. A drive shaft 80 comprising a wire turn is provided, the drive shaft 80 being partially covered by a polymeric sheath 82 such that a distal section 86 and a proximal section 87 of the drive shaft 60 are exposed. Drive shaft 80 includes a proximal stop 88P and a distal stop 88D. One or more features and advantages of the drive shaft 80, stops 88P and 88D, and polymer jacket 82 may be substantially similar to the corresponding features and advantages of the drive shaft and polymer jacket of the embodiment of fig. 3-5. The embodiment of fig. 8 adds a smooth metal liner 84 within the turns of the drive shaft 80 to the embodiment of fig. 4 and 5.

The smooth metal liner 84 is flexible and may be fixed at its proximal end. Unlike the embodiment of fig. 6, drive shaft 80 does not include internal proximal and/or distal stops to allow longitudinal movement of metal liner 84 therebetween. With metallic liner 84 fixed at its proximal end, metallic liner 84 does not rotate and, therefore, drive shaft 80 and polymer jacket 82 rotate independently on metallic liner 84. Alternatively, the lubricious metal liner 84 may not be fixed at its proximal end. In this case, the metal liner 84 may freely rotate within the drive shaft 80 during rotation of the drive shaft 80.

Fig. 9 is a longitudinal cross-sectional view of another embodiment of the present invention, the cross-section being generally parallel to the longitudinal axis a. A drive shaft 90 comprising a wire turn is provided, the drive shaft 90 being partially covered by a polymeric sheath 92, leaving a distal section 96 and a proximal section 97 of the drive shaft 90 exposed. The embodiment of fig. 9 adds a smooth metal liner 94 within the turns of the drive shaft 90 to the embodiment of fig. 2. One or more features and advantages of the drive shaft 90 and the polymer jacket 92 are substantially similar to the corresponding features and advantages of the drive shaft and polymer jacket of the embodiment of fig. 2.

The smooth metal liner 94 is flexible and not connected to the drive shaft 90. As shown in fig. 9, drive shaft 90 further includes an inner proximal stop 100P and an inner distal stop 100D. Alternatively, the inner stop of the drive shaft 90 may comprise only the distal inner stop 100D. Similar to the inner stops 70P and 70D of the embodiment of fig. 6, the inner stops 100P and 100D include protuberances extending radially inward from the inner surface of the drive shaft 90 into the internal cavity defined by the drive shaft 90. In some cases, the internal proximal stop 100P and/or the internal distal stop 100D can each include one or more protuberances, a plurality of proximal protuberances and/or a plurality of distal protuberances radially spaced from one another about an inner circumference of the respective proximal section 97 or distal section 96 of the drive shaft 90. In any such case, the metal liner 94 is free to move within the drive shaft 90 between the inner proximal stop 100P and/or the inner distal stop 100D, or between the proximal end of the drive shaft 90 and the inner distal stop 100D, in a manner similar to that described above in connection with the polymer sheath and drive shaft of the embodiment of fig. 3-5. Thus, the metal liner 94 is allowed to move longitudinally within a predetermined distance. If proximal stopper 100P and distal stopper 100D are used, the distance between proximal stopper 100P and distal stopper 100D may be greater than, or equal to, the length of metal liner 94 to define the desired longitudinal stroke length of metal liner 94. Accordingly, the metal liner may provide any or all of the advantages described above with respect to the metal liner 64 of the embodiment of fig. 6.

Unlike the embodiment of fig. 8, the drive shaft 80 does not include external proximal and/or distal stops to allow the polymer sheath 92 to move longitudinally therebetween. With polymer jacket 82 fixed at its proximal end, the polymer jacket does not rotate, and thus drive shaft 90 and metal liner 94 rotate independently within polymer jacket 92. Alternatively, the polymer sheath 92 may not be fixed at its proximal end. In this case, the polymer jacket 92 may freely rotate on the drive shaft 90 during rotation of the drive shaft 90. The polymer jacket 92 of the embodiment of fig. 9 may provide one or more of the advantages of the polymer jacket of fig. 2-8.

The description of the invention and its applications as set forth herein are illustrative and are not intended to limit the scope of the invention. The features of the various embodiments may be combined with other embodiments within the concept of the invention. Variations and modifications of the embodiments disclosed herein are possible, and practical alternatives to and equivalents of the various elements of the embodiments will be understood by those skilled in the art upon study of this patent document. These and other changes and modifications may be made to the embodiments disclosed herein without departing from the scope and spirit of the present invention.