EP4687760A1

EP4687760A1 - Catheter apparatus and methods

Info

Publication number: EP4687760A1
Application number: EP24720664.2A
Authority: EP
Inventors: Daniel HUANE; Andrew Stephen ENGLISH; Catherine CULLEN; Niall TIERNEY
Original assignee: Medtronic Inc
Current assignee: Medtronic Inc
Priority date: 2023-03-24
Filing date: 2024-03-22
Publication date: 2026-02-11
Also published as: WO2024206139A1

Abstract

Catheter apparatus includes a capsule bearing with a distal end portion attached to a proximal end portion of the capsule. The catheter apparatus further includes a shaft bearing attached to a distal end portion of a shaft. The capsule and the capsule bearing are configured to rotate together about a rotational axis relative to the shaft and the shaft bearing. A relative axial movement between the capsule bearing and the shaft bearing in a direction of the rotational axis is limited. In further aspects, methods of assembling a catheter apparatus comprise rotatably attaching a capsule bearing to a shaft bearing.

Description

CATHETER APPARATUS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The application claims the benefit of U.S. Provisional Application No. 63/454,534, filed March 24, 2023, and U.S. Provisional Application No. 63/568,081, filed March 21, 2024, the entire contents of which are incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to catheter apparatus and methods and, more particularly, to catheter apparatus comprising a capsule that rotates about a rotational axis relative to a shaft and methods of assembling catheter apparatus.

BACKGROUND

[0003] A human heart includes four heart valves that determine the pathway of blood flow through the heart: the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are atrioventricular valves, which are positioned between the atria and the ventricles, while the aortic and pulmonary valves are semilunar valves, which are positioned in the arteries leaving the heart. Ideally, native leaflets of a heart valve move apart from each other when the valve is in an open position, and include coaptation edges that meet or “coapf ’ when the valve is in a closed position. Valves may develop stenosis in which a valve does not open properly, and/or insufficiency or regurgitation in which retrograde blood flow occurs because a valve does not close properly. Stenosis and insufficiency may occur simultaneously in the same valve. The effects of valvular dysfunction vary, with insufficiency or regurgitation typically having severe physiological consequences for the patient.

[0004] It is known to provide prosthetic heart valves comprising valve leaflets and a valve skirt supported by an annular frame that can be delivered percutaneously using a catheter-based delivery system to replace a native heart valve. Known catheter apparatus that function as a catheter-based delivery system for the prosthetic heart valve comprises a capsule configured to retain the prosthetic heart valve in a collapsed or crimped orientation while advancing the prosthetic heart valve through the venous or arterial vasculature to the treatment site. To properly orient the prosthetic heart valve and/or to avoid torsional energy building up on the catheter-based delivery system, the capsule can be rotated relative to the shaft of the catheter apparatus. Once the prosthetic valve is positioned at the treatment site, for instance within a defective native heart valve, the annular frame may be released from the capsule and mechanically expanded to hold the prosthetic heart valve firmly in place while the valve skirt and valve leaflets are deployed to functionally replace the native heart valve. Alternatively, the capsule can be retracted and a self-expanding frame can gradually expand into position at the treatment site or a balloon may be employed to expand the frame at the treatment site.

[0005] There is a need for catheter apparatus that avoid undesired contact between the capsule bearing and the shaft. There is a further need for catheter apparatus and methods that provide for simplified assembly.

SUMMARY

[0006] The following presents a simplified summary of the disclosure to provide a basic understanding of some aspects described in the detailed description.

[0007] In aspects, a catheter apparatus comprises a capsule comprising a proximal end portion. The catheter apparatus further comprises a capsule bearing comprising a proximal end portion comprising a collar, a distal end portion attached to the proximal end portion of the capsule, and an outer circumferential recess defined between the distal end portion and the collar. The catheter apparatus further comprises a shaft bearing comprising an inner circumferential surface received within the outer circumferential recess. The capsule bearing is configured to rotate relative to the shaft bearing about a rotational axis of the capsule bearing, and a relative axial movement between the capsule bearing and the shaft bearing in a direction of the rotational axis is limited. The catheter apparatus further comprises a shaft comprising a distal end portion attached to the shaft bearing. The capsule and the capsule bearing are configured to rotate together about the rotational axis relative to the shaft and the shaft bearing.

[0008] In further aspects, a method of assembling a catheter apparatus comprises rotatably attaching a capsule bearing to a shaft bearing. The method comprises positioning an inner circumferential surface of the shaft bearing within an outer circumferential recess of the capsule bearing. The capsule bearing comprises a proximal end portion and a distal end portion. The capsule bearing is rotatable relative to the shaft bearing about a rotational axis of the capsule bearing and an axial movement of the capsule bearing relative to the shaft bearing in a direction of the rotational axis is limited. The method further comprises attaching a proximal end portion of a capsule to the distal end portion of the capsule bearing. The method still further comprises attaching a distal end portion of a shaft to the shaft bearing. The method assembles the catheter apparatus such that the capsule and the capsule bearing are configured to rotate together relative to the shaft and the shaft bearing.

[0009] Additional features and advantages of the aspects disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from that description or recognized by practicing the aspects described herein, including the detailed description which follows, the claims, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description present aspects intended to provide an overview or framework for understanding the nature and character of the aspects disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various aspects of the disclosure, and together with the description explain the principles and operations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features, aspects and advantages are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0011] FIG. 1 is a partial perspective view of portions of catheter apparatus in accordance with aspects of the disclosure;

[0012] FIG. 2 is an enlarged view of a portion of the catheter apparatus taken at view 2 of FIG. 1;

[0013] FIG. 3 is a cross-sectional view of a first embodiment of the catheter apparatus taken along line 3-3 of FIG. 2;

[0014] FIGS 4-7 illustrate steps of assembling the catheter apparatus of FIG. 3; [0015] FIG. 8 is a cross-sectional view of a second embodiment of the catheter apparatus taken along line 3-3 of FIG. 2;

[0016] FIG. 9 illustrates a perspective exploded view of a shaft bearing and a capsule bearing of the second embodiment of the catheter apparatus of FIG. 8 prior to assembly;

[0017] FIG. 10 illustrates a perspective view of the capsule bearing being rotatably coupled to the shaft bearing of FIG. 9;

[0018] FIG. 11 is a cross-sectional view of a third embodiment of the catheter apparatus taken along line 3-3 of FIG. 2;

[0019] FIG. 12 illustrates a perspective exploded view of a shaft bearing and a capsule bearing of the third embodiment of the catheter apparatus of FIG. 11 prior to assembly;

[0020] FIGS. 13 illustrates steps of assembling the shaft bearing being and the capsule bearing of the third embodiment of the catheter apparatus of FIGS. 11-12;

[0021] FIG. 14 is a cross-sectional view of the capsule bearing being rotatably coupled to the shaft bearing along line 14-14 of FIG. 10;

[0022] FIG. 15 is a cross-sectional view of the capsule bearing being rotatably coupled to the shaft bearing of FIGS. 11-13; and

[0023] FIG. 16 illustrates steps of attaching the shaft bearing of FIGS. 14-15 with the shaft of the catheter apparatus of FIGS. 8 and 11.

DETAILED DESCRIPTION

[0024] Aspects will now be described more fully hereinafter with reference to the accompanying drawings in which example aspects are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the aspects set forth herein.

[0025] Unless otherwise indicated, for the delivery system the terms "distal" and "proximal" are used in the following description with respect to a position or direction relative to the treating clinician. "Distal" and "distally" are positions distant from or in a direction away from the clinician, and "proximal" and "proximally" are positions near or in a direction toward the clinician. [0026] Diseases associated with heart valves, such as those caused by damage or a defect, can include stenosis and valvular insufficiency or regurgitation. For example, valvular stenosis causes the valve to become narrowed and hardened which can prevent blood flow to a downstream heart chamber from occurring at the proper flow rate and may cause the heart to work harder to pump the blood through the diseased valve. Valvular insufficiency or regurgitation occurs when the valve does not close completely, allowing blood to flow backwards, thereby causing the heart to be less efficient. A diseased or damaged valve, which can be congenital, age-related, drug-induced, or in some instances, caused by infection, can result in an enlarged, thickened heart that loses elasticity and efficiency. Some symptoms of heart valve diseases can include weakness, shortness of breath, dizziness, fainting, palpitations, anemia and edema, and blood clots which can increase the likelihood of stroke or pulmonary embolism. Symptoms can often be severe enough to be debilitating and/or life threatening.

[0027] Heart valve prostheses have been developed for repair and replacement of diseased and/or damaged heart valves. Such heart valve prostheses can be percutaneously delivered and deployed at the site of the diseased heart valve through catheter-based delivery systems. Such heart valve prostheses generally include a frame or stent and a prosthetic valve mounted within the frame. Such heart valve prostheses are delivered in a radially compressed or crimped configuration so that the heart valve prosthesis can be advanced through the patient’s vasculature. To properly orient the prosthetic heart valve and/or to avoid torsional energy building up on the catheter-based delivery system, the capsule can be rotated relative to the shaft of the catheter apparatus. Once positioned at the treatment site, the heart valve prosthesis is expanded to engage tissue at the diseased heart valve region to, for instance, hold the heart valve prosthesis in position.

[0028] FIG. 1 illustrates embodiments of a catheter apparatus 101 in accordance with aspects of the disclosure. The catheter apparatus 101 can comprise a flexible shaft 103 attached to a handle 105 at a proximal end 107 of the shaft 103. A distal end portion 109 of the shaft 103 can be attached to a capsule 111 by a rotational joint 301, 801, 1101. As shown schematically, the capsule 111 can house a collapsed or crimped prosthetic heart valve 113. In some embodiments, a retainer 117 may comprise a tab that interfaces with a corresponding structure of the prosthetic heart valve 113. A support rod 119 (not shown in FIGS. 3, 8 and 11 for simplicity) can extend through a central opening in the prosthetic heart valve 113 with the support rod 119 being attached to the retainer and a distal portion of the support rod 119 being attached to a conical tip 121 that can seal the distal end 123 of the capsule 111 with the crimped or collapsed prosthetic heart valve 113 loaded within the interior area of the capsule 111. The handle 105 can comprise an actuator designed to be engaged by a clinician to rotate the capsule 111 about a rotational axis 303, 803 (see FIGS. 3, 8 and 11) of a capsule bearing 305, 805. For example, as shown in FIG. 1, a knob 115 may be rotated to cause a corresponding rotation of the capsule 111 relative to the shaft 103. In operation, the capsule 111 loaded with the collapsed or crimped prosthetic heart valve 113 can be advanced through the patient’s vasculature while optionally rotating the knob 115 to rotate the capsule 111 together with the loaded prosthetic heart valve 113 about the rotational axis 303, 803 to release torsional energy that may otherwise be stored in the distal portions of the catheter apparatus 101 as the capsule 111 navigates through twists and/or turns in the patient’s vasculature. In further aspects, once the capsule 111 approaches the treatment site, the knob 115 may be rotated to change the rotational position of the prosthetic heart valve 113 relative to the treatment site until a desired rotational orientation of the prosthetic heart valve 113 relative to the treatment site is achieved. An actuator (not shown) on the handle 105 can then be engaged by the clinician to retract the capsule 111 relative to the prosthetic heart valve 113 such that the prosthetic heart valve 113 gradually self-expands as the capsule 111 retracts and released from the retainer 117 for proper installation at the treatment site. Although disclosed as a knob 115, in further embodiments, rotation of the capsule 111 may be achieved by other mechanisms including but not limited to a threaded or screw connection, a lever, or a rotatable wheel.

[0029] FIGS. 3, 8, and 11 illustrate alternative embodiments of rotational joints 301, 801, 1101 incorporating aspects of the disclosure. The capsule bearings 305, 805 can comprise a proximal end portion 307a, 807a and a distal end portion 307b, 807b attached to a proximal end portion 125 of the capsule 111. For example, the distal end portion 307b, 807b of the capsule bearing 305, 805 can be positioned within an inner passage 127 of the proximal end portion 125 of the capsule 111. In some embodiments, the capsule 111 can comprise a circular cylindrical capsule where the diameter of the inner passage 127 is approximately equal to the outer diameter of a circular cylindrical portion of the capsule bearing 305, 805 inserted into the inner passage 127. In the illustrated embodiment, the circular cylindrical portion of the capsule bearing 305, 805 can be inserted into the inner passage 127 until a proximal end surface 129 (see FIG. 7) abuts a shoulder 309, 809 of the capsule bearing 305, 805. In some embodiments, the capsule 111 can be fixedly attached to the capsule bearing 305, 805. In some embodiments, a press fit, crimping, and/or adhesive can be used to fixedly attach the capsule 111 to the capsule bearing 305, 805. In another embodiment, as shown in FIG.

2, the capsule proximal end of the capsule 111 can be welded to the shoulder 309, 809 of the capsule bearing 305, 805 as shown by weld seam 201. Consequently, the capsule 111 and the capsule bearing 305, 805 can be fixedly attached to one another so that the capsule 111 and the capsule bearing 305, 805 can be rotated together as a unit about the rotational axis 303, 803.

[0030] In some embodiments, the proximal end portion 307a, 807a of the capsule bearings 305, 805 can comprise a collar 313, 813. Furthermore, the capsule bearings 305, 805 of the rotational joints 301, 801, 1101 can each further comprise an outer circumferential recess 311, 811 defined between the distal end portion 307b, 807b of the capsule bearing 305, 805 and the collar 313, 813 of the proximal end portion 307a, 807a of the capsule bearing 305, 805. The outer circumferential recess 311, 811 can be rotationally symmetrical about the rotational axis 303, 803. For example, as shown, the outer circumferential recess 311, 811 can comprise a circular cylindrical base surface although conical or other rotationally symmetrical surface configurations may be provided in further embodiments.

[0031] As illustrated in FIGS. 3, 8, and 11, the rotational joints 301, 801, 1101 can each further include a shaft bearing 315, 815, 1115 comprising an inner circumferential surface 317, 817, 1117 received within the outer circumferential recess 311, 811. The inner circumferential surface 317, 817, 1117 can also be a rotationally symmetrical surface about the rotational axis 303, 803. The inner circumferential surface 317, 817, 1117 of each shaft bearing 315, 815, 1115 can match the base surface of the outer circumferential recess 311, 811. For instance, both the inner circumferential surface 317, 817, 1117 each shaft bearing and corresponding base surface of the outer circumferential recess 311, 811 of the capsule bearing 305, 805 can comprise a geometrically similar circular cylindrical surfaces, conical surfaces, or other rotationally symmetrical surfaces. In some embodiments, the geometrical cylindrical surfaces can be provided with a clearance sufficient to permit rotation of the surfaces relative to one another along the rotational axis 303, 803. For example, as illustrated, an inner diameter of the inner circumferential surface 317, 817, 1117 of each shaft bearing 315, 815, 1115 can be slightly larger than an outer diameter of a corresponding circular cylindrical base surface of the outer circumferential recess 311, 811 of the capsule bearing 305, 805 to provide enough clearance to permit free relative rotation of the geometrically similar surfaces about the rotational axis 303, 803.

[0032] A length of the inner circumferential surface 317, 817 and portions of the shaft bearing 315, 815, 1115 defining the inner circumferential surface 317, 817 that extend within the outer circumferential recess 311, 811 in the direction 304, 804 of the rotational axis 303, 803 can be slightly less than the corresponding length of the outer circumferential recess 311, 811 in the direction 304, 804 of the rotational axis 303, 803 to provide a slight clearance in the direction 304, 804 of the rotational axis 303, 803. Providing slight clearance in the direction 304, 804 permits free rotation of the capsule bearing 305, 805 relative to the shaft bearing 315, 815, 1115 about the rotational axis 303, 803 of the capsule bearing 305, 805. Furthermore, providing only a slight clearance in the direction 304, 804 limits a relative axial movement between the capsule bearing 305, 805 and the shaft bearing 315, 815, 1115 in the direction 304, 804 of the rotational axis 303, 803. Limiting the relative axial movement can help limit axial movement of the capsule 111 relative to the shaft 103, thereby providing for more accurate placement of the capsule 111 to deploy the crimped or collapsed prosthetic heart valve 113 from the capsule 111 at the correct location of the treatment site.

[0033] The shaft 103 comprises a distal end portion 109 that can be attached to the shaft bearing 315, 815, 1115. In some embodiments, the distal end portion of the shaft can be directly attached to the shaft bearing. Alternatively, as shown, the distal end portion 109 of the shaft 103 can be attached to the shaft bearing 315, 815,1115 indirectly by an attachment sleeve 133. As shown in FIGS. 3, 8 and 11, the attachment sleeve 133 can accommodate a difference in outer diameters between the shaft 103 and the shaft bearing 315, 815, 1115. In some embodiments, as shown in FIG. 6, the attachment sleeve 133 can comprise a cylindrical portion 601 and a proximally tapered portion 602. A proximal portion of the shaft bearing 315, 815, 1115 can be positioned within an inner passage 604 of the cylindrical portion 601 of the attachment sleeve 133. In some embodiments, the cylindrical portion 601 of the attachment sleeve 133 can comprise a circular cylindrical portion where the inner diameter of the inner passage 604 of the circular cylindrical portion of the attachment sleeve 133 is approximately equal to an outer diameter of a circular cylindrical proximal portion of the shaft bearing 315, 815, 1115 that is inserted into the inner passage 604. In the illustrated embodiment, the circular cylindrical proximal portion of the shaft bearing 315, 815, 1115 can be inserted such that an outer circumferential surface of the shaft bearing 315, 815, 1115 is received within the inner passage 604 and advanced until a distal end surface 608 of the cylindrical portion 601 of the attachment sleeve 133 abuts a shoulder 319, 819, 1119 of the shaft bearing 315, 815, 1115. In some embodiments, the cylindrical portion 601 of the attachment sleeve 133 can be fixedly attached to the shaft bearing 315, 815, 1115. In some embodiments, a press fit, crimping, and/or adhesive can be used to fixedly attach the attachment sleeve 133 to the shaft bearing 315, 815, 1115. In another embodiment, as shown in FIG. 2, the shoulder of the shaft bearing 315, 815, 1115 can be welded to the distal end of the attachment sleeve 133 as shown by weld seam 203.

[0034] As further illustrated, the proximally tapered portion 602 tapers as it extends from the cylindrical portion 601 in the direction 304, 804 of the rotational axis 303, 803. The proximally tapered portion 602 receives an outer circumferential surface 104 of the shaft 103. In some embodiments, the outer circumferential surface of the shaft bearing 315, 815, 1115 comprises an outer circular circumferential surface and the outer circumferential surface 104 of the shaft 103 can comprise an outer circular circumferential surface. As shown, the outer diameter of the outer circular circumferential surface of the shaft bearing 315, 815, 1115 can be greater than an outer diameter of the outer circumferential surface of the shaft 103. Thus, the attachment sleeve 133 comprises a cylindrical portion 601 and a proximally tapered portion 602 that permits attachment of the shaft bearing 315, 815, 1115 to the distal end portion 109 of the shaft 103 even though the distal end portion 109 of the shaft 103 comprises a smaller outer diameter than the outer diameter of the shaft bearing 315, 815, 1115.

[0035] To simplify manufacture of the attachment sleeve 133, as shown in FIG. 6, the proximally tapered portion 602 of the attachment sleeve 133 can comprise a plurality of protrusions 609 extending from the cylindrical portion 601 of the attachment sleeve 133 and radially arranged about the rotational axis 303, 803. For example, initially, the attachment sleeve 133 may comprise a single tubular segment with the same inner diameter throughout the length of the attachment sleeve 133. A plurality of slots 611 can be cut into a proximal portion of the attachment sleeve to extend through the proximal end of the sleeve to form the protrusions 609 that extend parallel to the rotational axis. The protrusions can thereafter be crimped or otherwise bent to the tapered configuration shown in FIG. 6. The slots 611 allow for tapering of a sleeve made from metal or other material without buckling or otherwise damaging the tapered portion of the sleeve.

[0036] As mentioned previously, the cylindrical portion 601 of the attachment sleeve 133 can be fixedly attached to the shaft bearing 315, 815, 1115 (e.g., by welding). Furthermore, the proximal end of the proximally tapered portion 602 of the attachment sleeve 133 can be fixedly attached to the distal end portion 109 of the shaft 103. For instance, as indicated by weld seam 205, the proximal end of the proximally tapered portion 602 of the attachment sleeve 133 can be welded to the outer circumferential surface 104 of the distal end portion 109 of the shaft 103. Once welded, in some embodiments (e.g., see FIG. 3), the distal end 321 of the distal end portion 109 of the shaft 103 can be spaced from a proximal end 408a of the capsule bearing 305 in the direction 304 of the rotational axis 303 to prevent contact between the distal end 321 of the distal end portion 109 of the shaft 103 and the proximal end 408a of the capsule bearing 305 when the capsule bearing 305 and the capsule 111 rotate together about the rotational axis 303 relative to the shaft 103, the attachment sleeve 133, and the shaft bearing 315.

[0037] As shown in FIGS. 8 and 11, in some embodiments, the shaft bearing 815, 1115 can comprise an inner circumferential recess 825, 1125 rotatably receiving the collar 313, 813 of the proximal end portion 307a, 807a of the capsule bearing 305, 805. Thus, two recesses can be provided to provide further stability and limit relative axial movement in the direction 304, 804 of the rotational axis 303, 803. Indeed, as discussed above with reference to the rotational joints 801, 1101 of FIGS. 8 and 11, the capsule bearing 305, 805 can comprise an outer circumferential recess 311, 811 receiving the inner circumferential surface 817, 1117 of the shaft bearing 815, 1115 and the shaft bearing 815, 1115 can comprise the inner circumferential recess 825, 1125 rotatably receiving the collar 313, 813 of the proximal end portion 307a, 807a of the capsule bearing 305, 805.

[0038] As further shown in FIGS. 8 and 11, the shaft bearing 815, 1115 can comprise a proximal flange 827, 1127 comprising a proximal end of the shaft bearing 815, 1115. The proximal flange 827, 1127 can be axially positioned between the collar 313, 813 of the capsule bearing 305, 805 and the distal end 321 of the distal end portion 109 of the shaft 103. As further illustrated, the inner circumferential recess 825, 1125 of the shaft bearing 815, 1115 can be axially positioned between inner circumferential surface 817, 1117 of the shaft bearing 815, 1115 and the proximal flange 827, 1127 of the shaft bearing 815, 1115. In such embodiments, the proximal flange 827, 1127 can prevent the collar 313, 813 of the capsule bearing 305, 805 from contacting the distal end 321 of the distal end portion 109 of the shaft 103. Rather, as the proximal flange 827, 1127 is part of the shaft bearing 815, 1115, there is no relative rotation between the proximal flange 827, 1127 and the shaft 103 since the shaft 103 and the shaft bearing 815, 1115 are fixedly attached together by the attachment sleeve 133.

[0039] As shown in FIG. 3, the shaft bearing 315 of the rotational joint 301 can comprise a single component as a ring that is at least partially received within the outer circumferential recess 311 of the capsule bearing 305. Alternatively, the shaft bearing comprises two or more components. For instance, as shown in FIGS. 8 and 11, the shaft bearing 815, 1115 of the rotational joint 801, 1101 can comprise a first portion 816a, 1115a attached to a second portion 816b, 1115b. In some embodiments, the first portion and the second portion are attached to one another along at least one plane that is coincident or parallel with the rotational axis. For example, as illustrated in FIGS. 8-10 and 14, in one embodiment, the shaft bearing 815 can comprise a first portion 816a and a second portion 816b that are attached together (e.g., by welding) along a plane 901 that is coincident or parallel with the rotational axis 803. As illustrated, the welding can occur at two locations (e g., with weld seams 821a, 821b) that are both coincident with the plane 901. In some embodiments, the first portion 816a and second portion 816b are identical although different configurations may be provided in further embodiments. Providing identical portions can be beneficial to save costs and inventory space.

[0040] The first portion 816a will now be described with the understanding that such description can equally apply to the second portion 816b since the first portion 816a is identical to the second portion 816b in the illustrated embodiment of the shaft bearing 815. Referring to FIG. 9, the first and second portions 816a, 816b can each comprise a semi-cylindrical circular surface 818a. Once the first and second portions 816a, 816b are attached together along the plane 901, the two semi-cylindrical surfaces 818a of the first and second portions 816a, 816b can form the integral cylindrical circular surface 818. Any excess portions of the weld seams 821a, 821b can be machined to provide a smooth transition between the first and second portions 816a, 816b to allow insertion of the of the proximal end of the rotational joint 801 into the inner passage 604 of the attachment sleeve 133 for a snug fit between the integral cylindrical circular surface 818 and the interior surface cylindrical portion defining the inner passage 604.

[0041] The first and second portions 816a, 816b can each further include an inner semi-circular surface 817a, and a semi-circular proximal flange 827a. The inner semicircular surfaces 817a of the first and second portions 816a, 816b can cooperate with one another to form the inner circumferential surface 817. Furthermore, the semi-circular proximal flanges 827a of the first and second portions 816a, 816b can cooperate with one another to form the circular proximal flange 827. As further illustrated in FIG. 9, the first and second portions 816a, 816b can each further include an inner semi-circular cylindrical recess 825a axially positioned between the semi-circular proximal flange 827a and the inner semi-circular surface 817a. The inner semi-circular cylindrical recesses 825a of the first and second portions 816a, 816b can cooperate with one another to form the inner circular cylindrical recess 825.

[0042] In some embodiments, the first portion and the second portion are attached to one another along a plane extending perpendicular to the rotational axis. For example, as illustrated in FIGS. 11-13 and 15, in one embodiment, the shaft bearing 1115 can comprise a first portion 1115a and a second portion 1115b that are attached together (e.g., by welding) along a plane 1121 that extends perpendicular with the rotational axis 303. The welding can occur at one or more locations that are coincident with the plane. For example, as shown, the welding can occur along a weld seam 1123 that can comprise the illustrated continuous circular weld seam although a plurality of intermittent or equally spaced weld seams can be arranged along the circular path within the plane 1121.

[0043] As shown in FIGS. 12-13, the first portion 1115a of the shaft bearing 1115 can comprise a ring including a circular cylindrical inner surface 1201 that can be slightly greater than equal to the outer diameter of an outer circular cylindrical surface 1203 of the capsule bearing 305 forming the base of the outer circumferential recess 311. The first portion 1115a can further comprises a first circular segment comprising a first outer cylindrical surface 1205 and a second segment with a second outer cylindrical surface 1207 being slightly larger than the first outer cylindrical surface 1205 to form the shoulder 1119 of the shaft bearing 1115. The second portion 1115b of the shaft bearing 1115 can comprise an end cap including a circular shroud 1210 comprising a circular cylindrical inner surface 1211 defining a cavity 1209 configure to receive the collar 313 of the capsule bearing 305. The circular cylindrical inner surface 1211 of the second portion 1115b of the shaft bearing 1115 that can be slightly greater than equal to the outer diameter of an outer circular cylindrical surface 1213 of the collar 313 of the capsule bearing 305.

[0044] As discussed previously, the capsule bearing 805 of the rotational joint 801 illustrated in FIGS. 8-10 and 14 can comprise a single component comprising a single monolithic body. In alternative embodiments, the capsule bearing can comprise two or more components that are attached together to function as the capsule bearing. For example, as shown in the embodiment of FIGS. 3-7 and the embodiment of FIGS. 11-13 and 15, the distal end portion 307b of the capsule bearing 305 can comprise a ring (see FIG. 6) receiving a segment 603 of a sleeve 605 of the capsule bearing 305 extending from the collar 313 of the capsule bearing 305. An outer circumferential surface 607 of the sleeve 605 defines the base of outer circumferential recess 311 of the capsule bearing 305 between the ring and the collar 313 of the capsule bearing 305. The ring 307b and the sleeve 605 can be attached together. For example, as shown, a distal end of the ring can be welded to a distal end of segment 603 of the sleeve 605. For instance, as shown, the welding can occur along a weld seam 306 that can comprise the illustrated circular weld seam although a plurality of intermittent or equally spaced weld seams can be arranged along the circular path of the interface at the distal end of the capsule bearing 305 between the ring and the segment 603 of the sleeve 605.

[0045] In further embodiments, as shown in FIGS. 3, 8 and 11, the catheter apparatus 101 can further comprise a torque coil 135 inserted through a lumen 106 of the shaft 103. A distal end portion of the torque coil 135 is attached to the capsule bearing 305, 805 and a proximal end portion of the torque coil 135 can be operably connected to an actuator (e.g., knob 115) of the handle 105. The torque coil 135 is rotatable relative to the shaft 103. In operation, a clinician can rotate the knob 115 to cause a corresponding rotation of the torque coil 135 relative to the shaft 103 and the shaft bearing 315, 815, 1115 that is fixedly attached to the shaft 103. The torque coil 135 will rotate together with the capsule bearing 305, 805 fixedly attached to the torque coil 135 and the capsule 111 fixedly attached to the capsule bearing 305, 805. As such, the clinician may rotate the knob 115 to cause the capsule 111 to rotate relative to the shaft 103 to release torque that may otherwise build up when navigating through the vasculature to the treatment site and/or to properly orient the crimped prosthetic heart valve at the treatment site before deploying the prosthetic heart valve from the capsule 111 approaches the treatment site. The torque coil can comprise a wide range of configurations. In some embodiments, as shown, the torque coil can comprise a wound coil of wire. As such, the coil of wire is free to bend along the elongated axis of the shaft. At the same time, the coils facilitate transmission of torque from the knob 115 to the capsule 111 to facilitate rotation of the capsule 111 in response to torque being applied to the torque coil by rotating the knob 115

[0046] A distal end 137 of the torque coil 135 can be positioned within an inner passage 402, 802 of the capsule bearing 305, 805. With reference to FIGS. 4 and 8, the inner passage 402, 802 of the capsule bearing 305, 805 extends from a proximal opening 406a, 806a at a proximal end 408a, 808a of the proximal end portion 307a, 807a of the capsule bearing 305, 805 to a distal opening 406b, 806b at a distal end 408b, 808b of the distal end portion 307b, 807b of the capsule bearing 305, 805. In some embodiments, inner passage 402, 802 of the capsule bearing 305, 805 can be dimensioned to prevent a movement of the distal end 137 of the torque coil 135 through the inner passage 402, 802 of the capsule bearing 305, 805 during assembly. In some embodiments, the movement can be from within the inner passage 402, 802 in a direction from the proximal opening 406a, 806a toward the distal opening 406b, 806b. For example, the inner passage 402, 802 can be dimensioned to function as a stop to allow a sufficient length of a distal end portion of the torque coil 135 to be inserted into the inner passage 402, 802 without the distal end 137 of the torque coil 135 exiting the distal opening 406b, 806b. Inserting a sufficient length of the distal end portion of the torque coil 135 into the inner passage 402, 802 of the capsule bearing 305, 805 can help limit or prevent bending stresses near the fixation location (e.g., weld location) of the torque coil 135 to the capsule bearing 305, 805. Thus, minimizing or preventing bending of a distal segment of the torque coil 135 within the inner passage 402, 802 of the capsule bearing 305, 805 can reduce possible failure of the fixed attachment between the capsule bearing 305, 805 and the torque coil 135 by limiting or preventing bending stresses near the fixation location.

[0047] In further embodiments, inner passage 402, 802 of the capsule bearing 305, 805 can be dimensioned to prevent a movement of the distal end 137 of the torque coil 135 through the inner passage 402, 802 of the capsule bearing 305, 805 during assembly in a direction from the distal opening 406b, 806b toward the proximal opening 406a, 806a. For example, in some embodiments, as described below, the inner passage 402, 802 may be dimensioned at the distal opening 406b, 806b to prevent insertion of the distal end 137 of the torque coil 135 through the distal opening 406b, 806b. As such, in some embodiments, the inner passage 402, 802 can be dimensions to prevent inadvertent installation of the torque coil 135 through the distal opening of the inner passage when proper installation of the torque coil 135 can only be achieved by inserting the distal end 137 of the torque coil 135 through the proximal opening of the inner passage 402, 802. In some embodiments, as described above, the inner passage 402, 802 can be dimensioned to: prevent the distal end 137 of the torque coil 135 from exiting the distal opening 406b, 806b when inserting the distal end of the torque coil into the inner passage during assembly; provide a predetermined length of the torque coil 135 within the inner passage 402, 802 that is sufficient to avoid bending stresses at the fixed attachment location; and/or avoid inserting the distal end 137 of the torque coil 135 into the wrong opening of the inner passage 402, 802 during assembly.

[0048] As illustrated, in some embodiments, the capsule bearing 305, 805 comprises a protrusion 330, 830 extending into the inner passage 402, 802 that dimensions the inner passage 402, 802 to prevent the movement of the distal end 137 of the torque coil 135 past the protrusion 330, 830 during assembly. In some embodiments, the protrusion can comprise one or a plurality of spaced protrusions that extend radially inwardly toward the rotational axis 303, 803 of the capsule bearing 305, 805. In some embodiments, one protrusion can at least partially define the distal opening 406b, 806b at the distal end 408b, 808b of the capsule bearing 305, 805 although the protrusion can be axially spaced from the distal opening in further embodiments. In some embodiments, a plurality of protrusions may be axially or circumferentially spaced relative to the rotational axis 303, 803. For example, a plurality of protrusions may be circumferentially spaced apart to circumscribe the rotational axis 303, 803 while at least partially defining the distal opening 406b, 806b at the distal end 408b, 808b of the capsule bearing 305, 805.

[0049] As shown in the illustrated embodiment, the distal end portion 307b, 807b of the capsule bearing 305, 805 can comprise the protrusion 330, 830. Furthermore, in some embodiments the protrusion 330, 830 can comprise an inwardly extending circumferential flange that circumscribes (e.g., continuously circumscribes) the rotational axis 303, 803 of the capsule bearing 305, 805. As illustrated, the inwardly extending circumferential flange can comprise a circular inner edge 331, 831 facing the rotational axis 303, 803 of the capsule bearing 305, 805. The circular inner edge 331, 831 can comprise a continuous edge with a center coincident with the rotational axis 303, 803 and comprising a diameter “DI”. As shown in FIGS. 1 and 8, the protrusions 330, 830 can comprise a shoulder 138, 838 that can provide a seat for the distal end 137 of the torque coil 135 and therefore act as a stop to facilitate insertion of a predetermined length of the distal end portion of the torque coil 135 into the inner passage 402, 802 of the capsule bearing 305, 805 during assembly.

[0050] As shown, in some embodiments, the inwardly extending circumferential flange can be positioned at the distal end 408b, 808b of the capsule bearing 305, 805 wherein the circular inner edge 331, 831 of the inwardly extending circumferential flange defines the distal opening 406b, 806b of the capsule bearing 305, 805. The outer diameter of the torque coil 135 can be greater than the diameter “DI” of the circular inner edge 331, 831 wherein inwardly extending circumferential flange acts as an axial stop against the distal end 137 of the torque coil 135 axially advancing within the inner passage 402, 802 during assembly. Indeed, the inwardly extending circumferential flange of the protrusion 330, 830 provides the shoulder 138, 838 of the protrusion 330, 830 as a circular surface circumscribing the rotational axis 303, 803. The circular surface can face a direction of the rotational axis 303, 803 (e.g., perpendicular to the rotational axis) towards the proximal end portion 307a, 807a of the capsule bearing 305, 805. As shown, once assembled, in some embodiments, the distal end 137 of the torque coil 135 can abut the protrusion 330, 830 by abutting the shoulder 138, 838 of the protrusion 330,830.

[0051] As shown, the torque coil 135 comprises an inner surface 139 defining a coil lumen 141. In some embodiments, the inner surface 139 of the torque coil 135 can define a circular opening 143 into the coil lumen 141 at the distal end 137 of the torque coil 135. The circular opening 143 can comprise a diameter “D2” as illustrated, for example, in FIG. 3. As shown, in some embodiments, the diameter “DI” of the circular inner edge 331, 831 of the inwardly extending circumferential flange can be substantially equal to the diameter “D2” of the circular opening 143 of the torque coil 135. Providing the diameter “DI” substantially equal to the diameter “D2” can facilitate a smooth transition between the coil lumen 141 and the inner passage 402, 802 and can provide an ideal transition for fixedly attaching the distal end 137 of the torque coil 135 within the inner passage 402, 802 of the capsule bearing 305, 805. For example, as shown, the distal end 137 of the torque coil 135 can be butt welded with the protrusion 330, 830 (e.g., inwardly extending circumferential flange) by way of a weld seam 145.

[0052] Methods of assembling the catheter apparatus 101 in accordance with aspects of the disclosure will now be described. In some embodiments, the method can begin by assembling the rotational joint 301, 801, 1101. For example, in some embodiments, the method can begin by assembling the rotational joint 301 of FIG. 3. The rotational joint 301 can be assembled by rotatably attaching the capsule bearing 305 the shaft bearing 315 by positioning the inner circumferential surface 317 of the shaft bearing 315 within the outer circumferential recess 311 of the capsule bearing 305. The capsule bearing 305 can therefore be rotatable relative to the shaft bearing 315 about the rotational axis 303 of the capsule bearing 305. Furthermore, once rotatably attached, an axial movement of the capsule bearing 305 relative to the shaft bearing 315 in the direction 304 of the rotational axis 303 is limited. More specifically, as shown in FIGS. 4-5, example methods of assembling the rotational joint 301 can begin with axially aligning the shaft bearing 315 with the sleeve 605. In some embodiments, the shaft bearing 315 can be moved relative to the sleeve 605 in the direction 304 of the rotational axis 303 such that the sleeve 605 is slidably inserted through the interior of the shaft bearing 315. The shaft bearing 315 can be inserted until an end surface 501 of the shaft bearing 315 abuts a shoulder 503 of the collar 313. Once positioned as shown in FIG. 3, the shaft bearing 315 is rotatably received over the sleeve 605 with the outer circumferential surface 607 of the sleeve 605 being rotatably and slidably positioned against the inner circumferential surface 317 of the shaft bearing 315. Next, as shown in FIG. 5, the distal end portion 307b of the capsule bearing 305 (e.g., the ring) can be axially aligned with the sleeve 605 while the sleeve 605 of the capsule bearing 305 is inserted through the interior of the shaft bearing 1115. In some embodiments, the ring 307b of the capsule bearing 305 can be moved relative to the sleeve 605 in the direction 304 of the rotational axis 303 such that the sleeve 605 of the capsule bearing 305 is inserted through the interior area of the ring 307b of the capsule bearing 305. In some embodiments, as shown in FIG. 6, an end surface 603a of the segment 603 can be positioned flush relative to the end surface 601a of the ring 307b.

[0053] A weld seam 306 can be applied to the interface between the end surfaces 601a, 603a to weld the distal end of the ring 307b to the distal end of the sleeve 605 to fixedly attach the ring 307b to the sleeve 605 of the capsule bearing 305. Once fixedly attached, the rotational joint 301 is fully assembled wherein the shaft bearing 315 is trapped within the outer circumferential recess 311 of the capsule bearing 305. Furthermore, once attached, the outer circumferential surface 607 of the sleeve 605 of the capsule bearing 305 defines a circumferential base of the outer circumferential recess 311 of the capsule bearing 305. The capsule bearing 305 is thereafter rotatable relative to the shaft bearing 315 about the rotational axis of 303 of the capsule bearing 305 and an axial movement of the capsule bearing 305 relative to the shaft bearing 315 in the direction 304 of the rotational axis 303 is limited. Indeed, a close tolerance may be provided between the length of the outer circumferential recess 311 of the capsule bearing 305 and the length of the shaft bearing 315 in the direction 304 of the rotational axis 303 to minimize relative axial movement while allowing rotation of the capsule bearing 305 relative to the shaft bearing 315.

[0054] In another embodiment, the method of assembling the catheter apparatus 101 can begin by assembling the rotational joint 801 of FIG 8. As shown in FIGS. 9-10, the method can include rotatably attaching the capsule bearing 805 the shaft bearing 815 by positioning the inner circumferential surface 817 of the shaft bearing 815 within the outer circumferential recess 811 of the capsule bearing 805. As shown in FIG. 8, in some embodiments, rotatably attaching the capsule bearing 805 to the shaft bearing 815 can further comprise positioning the collar 813 of the capsule bearing 805 within an inner circumferential recess 825 of the shaft bearing 815.

[0055] FIGS. 9-10 illustrate example steps to assemble the rotational joint 801 of FIG. 8. In some embodiments, positioning the collar 813 of the capsule bearing 805 within the inner circumferential recess 825 of the shaft bearing 815 can comprise attaching the first portion 816a of the shaft bearing 815 to the second portion 816b of the shaft bearing 815. The two portions 816a, 816b can be positioned together such that the inner semi-circular surfaces 817a of the two portions 816a, 816b of the shaft bearing 815 are trapped within the outer circumferential recess 811 of the capsule bearing 805. Furthermore, positioning the two portions 816a, 816b together can trap the collar 813 within the two inner semi-circular cylindrical recesses 825a of the two portions 816a, 816b of the shaft bearing 815. Once positioned together, two facing surfaces 829a of the two portions 816a, 816b can face one another and, in some embodiments, abut one another. Furthermore, once positioned together, the two facing surfaces 829b of the two portions 816a, 816b can also face one another and, in some embodiments, abut one another. Once positioned together, the facing surfaces 829a, 829b of the two portions 816a, 816b of the shaft bearing 815 can extend along at least one plane 901 that is coincident or parallel with the rotational axis 803 of the capsule bearing 805. For instance, although not shown, in some embodiments, the facing surfaces 829a, 829b of the first portion 816a can extend along a first plane and the facing surfaces 829a, 829b of the second portion 816b can extend along a second plane parallel to the first plane and the rotational axis 803 of the capsule bearing 805. In the illustrated embodiment, it will be appreciated that the facing surfaces 829a, 829b of the two portions 816a, 816b can both be coincident with one another and the rotational axis 803 of the capsule bearing 805. As the facing surfaces 829a, 829b of the two portions 816a, 816b are all coincident with the plane 901 and the rotational axis 803, the facing surfaces 829a of the two portions 816a, 816b abut one another along the plane 901 and the facing surfaces 829b of the two portions 816a, 816b also abut one another along the plane 901.

[0056] Once the facing surfaces 829a, 829b of the two portions 816a, 816b are positioned adjacent one another (e.g., abut one another), the method can comprise attaching the first portion 816a of the shaft bearing 815 to the second portion 816b of the shaft bearing 815 along at least one plane 901 that is coincident or parallel with the rotational axis 803 of the capsule bearing 805. In some embodiments, attaching can be carried out by welding the first portion 816a of the shaft bearing 815 to the second portion 816b of the shaft bearing 815. For in stance, the welding can occur at two locations (e.g., with weld seams 821a, 821b) that are both coincident with the plane 901. Once rotatably attached, the capsule bearing 805 can be rotatable relative to the shaft bearing 815 about the rotational axis 803 of the capsule bearing 805. Furthermore, once rotatably attached, an axial movement of the capsule bearing 805 relative to the shaft bearing 815 in the direction 804 of the rotational axis 803 is limited.

[0057] In another embodiment, the method of assembling the catheter apparatus 101 can begin by assembling the rotational joint 1101 of FIG 11. As shown in FIGS. 12-13, the method can include rotatably attaching the capsule bearing 305 to the shaft bearing 1115 by positioning the inner circumferential surface 1201 of the shaft bearing 1115 within the outer circumferential recess 311 of the capsule bearing 305. Rotatably attaching the capsule bearing 305 to the shaft bearing 1115 further comprises positioning the collar 313 of the capsule bearing 305 within the inner circumferential recess 1125 of the shaft bearing 1115. More specifically, as shown in FIGS. 12-13, example methods of assembling the rotational joint 1101 can begin with axially aligning the first portion 1115a of the shaft bearing 1115 with the sleeve 605 of the capsule bearing 305. In some embodiments, the first portion 1115a of the shaft bearing 1115 can be moved relative to the sleeve 605 in the direction 304 of the rotational axis 303 such that the sleeve 605 is slidably inserted through the interior of the first portion 1115a of the shaft bearing 1115. The first portion 1115a can be inserted until an end surface 1301 of the first portion 1115a of the shaft bearing 1115 abuts the shoulder 503 of the collar 313. Once positioned as shown in FIG. 13, the first portion 1115a of the shaft bearing 1115 is rotatably received over the sleeve 605 with the outer circumferential surface 607 of the sleeve 605 being rotatably and slidably positioned against the circular cylindrical inner surface 1201 of the first portion 1115a of the shaft bearing 1115. Next, the distal end portion 307b of the capsule bearing 305 comprising the ring can be axially aligned with the sleeve 605 while the sleeve 605 of the capsule bearing 305 is inserted through the interior of the first portion 1115a of the shaft bearing 1115. In some embodiments, the ring 307b of the capsule bearing 305 can be moved relative to the sleeve 605 in the direction 304 of the rotational axis 303 such that the sleeve 605 of the capsule bearing 305 is inserted through the interior area of the ring 307b of the capsule bearing 305. In some embodiments, as shown in FIG. 13, an end surface 603a of the segment 603 can be positioned flush relative to the end surface 601a of the ring 307b.

[0058] As shown in FIG. 13, a weld seam 306 can be applied to the interface between the end surfaces 601a, 603a to weld the distal end of the ring 307b to the distal end of the sleeve 605 to fixedly attach the ring 307b to the sleeve 605 of the capsule bearing 305. Once fixedly attached, the first portion 1115a of the shaft bearing 1115 is trapped within the outer circumferential recess 311 of the capsule bearing 305. Furthermore, once attached, the outer circumferential surface 607 of the sleeve 605 of the capsule bearing 305 defines a circumferential base of the outer circumferential recess 311 of the capsule bearing 305. The capsule bearing 305 is thereafter rotatable relative to the first portion 1115a of the shaft bearing 1115 about the rotational axis of 303 of the capsule bearing 305 and an axial movement of the capsule bearing 305 relative to the first portion 1115a of the shaft bearing 1115 in the direction 304 of the rotational axis 303 is limited. Indeed, a close tolerance may be provided between the length of the outer circumferential recess 311 of the capsule bearing 305 and the length of the first portion 1115a of the shaft bearing 1115 in the direction 304 of the rotational axis 303 to minimize relative axial movement while allowing rotation of the capsule bearing 305 relative to the first portion 1115a of the shaft bearing 1115.

[0059] As further shown in FIG. 13, The second portion 1115b of the shaft bearing 1115 can be aligned along the rotational axis 303 with the subassembly of the first portion 1115a of the shaft bearing 1115 rotatably attached to the capsule bearing 305. In some embodiments, the subassembly can then be moved relative to the second portion 1115b in the direction 304 of the rotational axis 303 until the end surface 1301 of the first portion 1115a is positioned adjacent (e.g., abuts) a facing end surface 1303 of the second portion 1115b. The subassembly can then be attached to the second portion 1115b such that the collar 313 of the capsule bearing 305 is positioned within the circular cylindrical inner surface 1211. As shown in FIG. 15, in some embodiments, the first portion 1115a of the shaft bearing 1115 can be attached to the second portion 1115b of the shaft bearing 1115 along the plane 1121 that can be perpendicular to the rotational axis 303 of the capsule bearing 305. In some embodiments, the facing end surfaces 1301, 1303 of the first and second portions 1115a, 1115b can abut one another and extend coincident with the plane 1121. The first and second portions 1115a, 1115b can then be fixedly attached to one another, for example, with the circumferential weld seam 1123 that circumscribes the rotational axis 303 of the capsule bearing 305. The capsule bearing 305 can therefore be rotatable relative to the shaft bearing 1115 about the rotational axis 303 of the capsule bearing 305. Furthermore, once rotatably attached, an axial movement of the capsule bearing 305 relative to the shaft bearing 1115 in the direction 304 of the rotational axis 303 is limited.

[0060] Assembly of the catheter apparatus 101 can thereafter continue with using one of the assembled rotational joints 301, 801, 1101 to attach the proximal end portion 125 of the capsule 111 to the distal end portion 109 of the shaft 103. For instance, the shaft bearing 315, 815, 1115 and the distal end portion of the shaft 103 can be attached together with the attachment sleeve 133. For example, with reference to FIGS. 6-7 the method of assembling can comprise inserting an outer cylindrical surface of the shaft bearing 315 into the cylindrical portion 601 of the attachment sleeve 133 until the distal end surface 608 of the cylindrical portion 601 of the attachment sleeve 133 abuts the shoulder 319 of the shaft bearing 315. Likewise, with reference to FIGS. 14-16, the method of assembling can comprise inserting the outer cylindrical surface of the shaft bearing 815, 1115 into the cylindrical portion 601 of the attachment sleeve 133 until the distal end surface 608 of the cylindrical portion 601 of the attachment sleeve 133 abuts the shoulder 819, 1119 of the shaft bearing 815, 1115. Next, the cylindrical portion 601 of the attachment sleeve 133 can be welded to the shaft bearing 315, 815, 1115 as illustrated by the weld seam 203.

[0061] Referring to FIGS. 6 and 16, attaching the shaft bearing 315, 815, 1115 to the distal end portion 109 of the shaft 103 can further comprise inserting an outer circumferential surface 104 of the shaft 103 into the interior of the proximally tapered portion 602 of the attachment sleeve 133 extending from the cylindrical portion 601 of the attachment sleeve 133. The proximally tapered portion 602 of the attachment sleeve 133 can then be welded to the outer circumferential surface 104 of the shaft 103 as indicated by weld seam 205 in FIGS. 8 and 11.

[0062] In the embodiment shown in FIG. 3, the proximally tapered portion 602 of the attachment sleeve 133 can be welded to the outer circumferential surface 104 of the shaft 103 such that the distal end 321 of the distal end portion 109 of the shaft 103 is axially spaced a distance from the proximal end 408a of the capsule bearing 305. The space between the distal end 321 and the proximal end 408a allows the capsule bearing 305 to rotate relative to the shaft 103 without the proximal end 408a of the capsule bearing 305 contacting the distal end 321 of the distal end portion 109 of the shaft 103. In the embodiments shown in FIGS. 8 and 11, the shaft bearings 815, 1115 can comprise the proximal flange 827, 1127 that blocks contact between the proximal end 408a of the capsule bearing 305 and the distal end 321 of the distal end portion 109 of the shaft 103. As there is no relative rotation between the shaft bearing 815, 1115 and the shaft 103, the flange 827, 1127 can protect the distal end 821 of the shaft 103 from being damaged by rotational contact and/or undesired frictional contact that may resist rotation of the capsule 111 relative to the shaft 103 in use.

[0063] The method further comprises inserting the distal end 137 of a torque coil 135 through the proximal opening 406a, 806a and into the inner passage 402, 802 of the capsule bearing 305, 805. Furthermore, in some embodiments, the protrusion 330, 830 at least partially defines the distal opening 406b, 806b to prevent insertion of the distal end 137 of the torque coil 135 into the distal opening 406b, 806b. As such, the distal end 137 of the torque coil 135 can be reliably inserted through the proximal opening 406a, 806a and then further inserted toward the distal opening 406b, 806b until the distal end 137 of the torque coil 135 abuts the protrusion 330, 830 that prevents the distal end 137 of the torque coil 135 from exiting the distal opening 406b, 806b of the capsule bearing 305, 805

[0064] As shown, the protrusion 330, 830 can comprise the illustrated inwardly extending circumferential flange wherein the circular inner edge 331, 831 of the inwardly extending circumferential flange defines the distal opening 406b, 806b of the capsule bearing 305, 805. Fixedly attaching the distal end 137 of the torque coil 135 to the capsule bearing 305, 805 is therefore simplified since the distal end 137 is positioned adjacent the distal opening 406b, 806b. Indeed, the method can comprise fixedly attaching the torque coil 135 to the capsule bearing 305, 805 while the distal end 137 of the torque coil 135 abuts against the protrusion 330, 830. The distal opening 406b, 806b can therefore be used as an access opening to fixedly attach (e.g., by welding) the torque coil 135 to the capsule bearing 305, 805. Abutting the distal end 137 of the torque coil 135 with the protrusion 330, 830 can align the inner surface 139 of the torque coil 135 to be substantially flush with the circular inner edge 331, 831 of the inwardly extending circumferential flange. Such alignment can facilitate welding wherein a circumferential weld seam 145 can be provided to circumferentially fixedly attached the distal end 137 of the torque coil 135 to the inwardly extending circumferential flange while the inner surface 139 of the torque coil 135 is substantially flush with the circular inner edge 331, 831 of the inwardly extending circumferential flange and while the distal end 137 of the torque coil 135 abuts the protrusion 330, 830. As shown, the circumferential weld seam 145 can be provided by butt welding the distal end 137 of the torque coil 135 with the inwardly extending circumferential flange.

[0065] Methods can further comprise attaching the proximal end portion 125 of the capsule 111 to the distal end portion 307b, 807b of the capsule bearing 305, 805. For example, as shown in FIGS. 7 and 11, the proximal end portion 125 of the capsule 111 can be axially aligned with the distal end portion 307b of the capsule bearing 305 along the rotational axis 303. The capsule 111 can then be moved in the direction 304 relative to the capsule bearing 305 such that the distal end portion 307b of the capsule bearing 305 is received within the inner passage 127 of the proximal end portion 125 of the capsule 111. The capsule 111 can be moved relative to the distal end portion 307b until the proximal end surface 129 of the capsule 111 abuts the shoulder 309 of the distal end portion 307b. The proximal end portion 125 of the capsule 111 can then be attached to the distal end portion 307b of the capsule bearing 305 by welding the proximal end portion of the capsule 111 to the distal end portion 307b of the capsule bearing 305 as indicated by weld seam 201.

[0066] Referring to the embodiment of FIG. 8, the proximal end portion 125 of the capsule 111 can be axially aligned with the distal end portion 807b of the capsule bearing 805 along the rotational axis 803. The capsule 111 can then be moved in the direction 804 relative to the capsule bearing 805 such that the distal end portion 807b of the capsule bearing 805 is received within the inner passage 127 of the proximal end portion 125 of the capsule 111. The capsule 111 can be moved relative to the distal end portion 807b until the proximal end surface 129 of the capsule 111 abuts the shoulder 809 (see FIG. 14) of the distal end portion 807b. The proximal end portion 125 of the capsule 111 can then be attached to the distal end portion 807b of the capsule bearing 805 by welding the proximal end portion of the capsule 111 to the distal end portion 807b of the capsule bearing 805 as indicated by weld seam 201.

[0067] The various embodiments of the rotational joints 301, 801, 1101 can simplify assembly and provide benefits once assembled. For instance, the attachment sleeve 133 can allow attachment between a capsule 111 and the shaft 103 with different outer diameters. Furthermore, as shown in FIG. 3, the attachment sleeve 133 can permit spacing of the distal end 321 of the shaft 103 from the proximal end 408a of the capsule bearing 305; thereby avoiding rotatable engagement between the capsule bearing and the shaft 103 that may damage the end of the shaft and/or cause undesired resistance in rotation due to frictional contact between the distal end 321 of the shaft and the proximal end 408a of the capsule bearing 305. Furthermore, as shown in FIG. 8, the capsule bearing 805 may be formed as a one-piece member that can simplify fabrication. Furthermore, in some embodiments, as shown in FIG. 3, the distal end portion 307b of the capsule bearing 305 may be substantially identical to the shaft bearing 315. The geometric similarity may be beneficial to reduce inventory space and can be particularly useful in embodiments where the distal end portion 307b of the capsule bearing is made from the same material as the shaft bearing 315. However, geometric similarity may cause errors in assembly due to confusion between the two substantially identical components. For instance, problems may occur due to improper installation when the components are made from different materials or have other characteristics that are not visually apparent during assembly. For example, there may be a desire to fabricate the shaft bearing 315 from a first material (e.g., stainless steel) and the capsule bearing from another material (e.g., niobium). To avoid such confusion, in some embodiments, the capsule bearing 805 can comprise a single monolithic member as shown in FIG. 8. Still further, the embodiments of the rotational joints 801, 1101 can provide the shaft bearing 815, 1115 with flanges 827, 1127, that can avoid rotational contact between the distal end 321 of the shaft 103 and the proximal end of the capsule bearing 305, 805.

[0068] In accordance with the disclosure, non-limiting aspects of the disclosure will now be described. Various combinations of the aspects can be provided in accordance with the disclosure.

[0069] Aspect 1. A catheter apparatus comprises a capsule and a capsule bearing. The capsule bearing comprises a distal end portion attached to a proximal end portion of the capsule. The capsule bearing further comprises an outer circumferential recess defined between the distal end portion of the capsule bearing and a collar of the capsule bearing. The catheter apparatus further comprises a shaft bearing comprising an inner circumferential surface received within the outer circumferential recess of the capsule bearing. The capsule bearing is configured to rotate relative to the shaft bearing about a rotational axis of the capsule bearing, and a relative axial movement between the capsule bearing and the shaft bearing in a direction of the rotational axis is limited. The catheter apparatus further comprises a shaft comprising a distal end portion attached to the shaft bearing. The capsule and the capsule bearing are configured to rotate together about the rotational axis relative to the shaft and the shaft bearing.

[0070] Aspect 2. The catheter apparatus of Aspect 1, wherein the distal end portion of the capsule bearing is positioned within an inner passage of the proximal end portion of the capsule. [0071] Aspect 3. The catheter apparatus of any one of Aspects 1-2, further comprising an attachment sleeve attaching the distal end portion of the shaft to the shaft bearing.

[0072] Aspect 4. The catheter apparatus of Aspect 3, wherein the attachment sleeve comprises a cylindrical portion receiving an outer circumferential surface of the shaft bearing and a proximally tapered portion extending from the cylindrical portion. The proximally tapered portion receives an outer circumferential surface of the shaft.

[0073] Aspect 5. The catheter apparatus of Aspect 4, wherein the outer circumferential surface of the shaft bearing comprises an outer circular circumferential surface and the outer circumferential surface of the shaft comprises an outer circular circumferential surface. An outer diameter of the outer circular circumferential surface of the shaft bearing is greater than an outer diameter of the outer circumferential surface of the shaft.

[0074] Aspect 6. The catheter apparatus of any one of Aspects 4-5, wherein the proximally tapered portion of the attachment sleeve comprises a plurality of protrusions extending from the cylindrical portion of the attachment sleeve and radially arranged about the rotational axis.

[0075] Aspect 7. The catheter apparatus of Aspects 4-6, wherein the cylindrical portion of the attachment sleeve is welded to the shaft bearing and the proximally tapered portion of the attachment sleeve is welded to the shaft.

[0076] Aspect 8. The catheter apparatus of any one of Aspects 1-7, wherein the distal end portion of the shaft is axially spaced from the proximal end portion of the capsule bearing in the direction of the rotational axis. The capsule bearing is configured to rotate about the rotational axis relative to the shaft bearing without the proximal end portion of the capsule bearing contacting the distal end portion of the shaft.

[0077] Aspect 9. The catheter apparatus of any one of Aspects 1-7, wherein the shaft bearing comprises an inner circumferential recess rotatably receiving the collar of the capsule bearing.

[0078] Aspect 10. The catheter apparatus of Aspect 9, wherein the shaft bearing comprises a proximal flange comprising a proximal end of the shaft bearing. The proximal flange is axially positioned between the collar of the capsule bearing and the distal end portion of the shaft. The proximal flange prevents the collar of the capsule bearing from contacting the distal end portion of the shaft.

[0079] Aspect 11. The catheter apparatus of Aspect 10, wherein the inner circumferential recess of the shaft bearing is axially positioned between inner circumferential surface of the shaft bearing and the proximal flange of the shaft bearing.

[0080] Aspect 12. The catheter apparatus of any one of Aspect 9-11, wherein the shaft bearing comprises a first portion attached to a second portion.

[0081] Aspect 13. The catheter apparatus of Aspect 12, wherein the first portion of the shaft bearing is welded to the second portion of the shaft bearing.

[0082] Aspect 14. The catheter apparatus of any one of Aspects 12-13, wherein the first portion of the shaft bearing and the second portion of the shaft bearing are attached to one another along a plane extending perpendicular to the rotational axis.

[0083] Aspect 15. The catheter apparatus of Aspect 1-14, wherein the distal end portion of the capsule bearing comprises a ring receiving a segment of a sleeve of the capsule bearing extending from the collar of the capsule bearing. An outer circumferential surface of the sleeve defines the outer circumferential recess of the capsule bearing between the ring and the collar of the capsule bearing.

[0084] Aspect 16. The catheter apparatus of Aspect 15, wherein a distal end of the ring is welded to a distal end of the segment of the sleeve.

[0085] Aspect 17. The catheter apparatus of any one of Aspects 12-13, wherein the first portion and the second portion are attached to one another along at least one plane that is coincident or parallel with the rotational axis.

[0086] Aspect 18. The catheter apparatus of any one of Aspects 12-13 and 17, wherein the first portion and second portion are identical.

[0087] Aspect 19. The catheter apparatus of any one of Aspects 1-18, further comprising a torque coil extending through a lumen of the shaft. A distal end of the torque coil is positioned within an inner passage of the capsule bearing. The inner passage of the capsule bearing extends from a proximal opening at a proximal end of the proximal end portion of the capsule bearing to a distal opening at a distal end of the distal end portion of the capsule bearing. The inner passage of the capsule bearing is dimensioned to prevent a movement of the distal end of the torque coil through the inner passage of the capsule bearing during assembly.

[0088] Aspect 20. The catheter apparatus of Aspect 19, wherein the movement is from within the inner passage in a direction from the proximal opening toward the distal opening.

[0089] Aspect 21. The catheter apparatus of any one of Aspects 19-20, wherein the capsule bearing comprises a protrusion extending into the inner passage that dimensions the inner passage to prevent the movement of the distal end of the torque coil past the protrusion during assembly.

[0090] Aspect 22. The catheter apparatus of Aspect 21, wherein the distal end portion of the capsule bearing comprises the protrusion.

[0091] Aspect 23. The catheter apparatus of any one of Aspects 21-22, wherein the protrusion comprises an inwardly extending circumferential flange that circumscribes the rotational axis of the capsule bearing.

[0092] Aspect 24. The catheter apparatus of Aspect 23, wherein the inwardly extending circumferential flange comprises a circular inner edge facing the rotational axis of the capsule bearing.

[0093] Aspect 25. The catheter apparatus of Aspect 24, wherein the circular inner edge of the inwardly extending circumferential flange defines the distal opening of the capsule bearing.

[0094] Aspect 26. The catheter apparatus of any one of Aspects 24-25, wherein the torque coil comprises an inner surface defining a coil lumen. The inner surface of the torque coil defines a circular opening into the coil lumen at the distal end of the torque coil. A diameter of the circular opening of the torque coil is substantially equal to a diameter of the circular inner edge of the inwardly extending circumferential flange.

[0095] Aspect 27. The catheter apparatus of any one of Aspects 21-26, wherein the distal end of the torque coil abuts the protrusion.

[0096] Aspect 28. The catheter apparatus of any one of Aspects 19-27, wherein the torque coil is fixedly attached within the inner passage of the capsule bearing.

[0097] Aspect 29. A method of assembling a catheter apparatus comprises rotatably attaching a capsule bearing to a shaft bearing. The method comprises positioning an inner circumferential surface of the shaft bearing within an outer circumferential recess of the capsule bearing. The capsule bearing is rotatable relative to the shaft bearing about a rotational axis of the capsule bearing and an axial movement of the capsule bearing relative to the shaft bearing in a direction of the rotational axis is limited. The method further comprises attaching a proximal end portion of a capsule to a distal end portion of the capsule bearing. The method still further comprises attaching a distal end portion of a shaft to the shaft bearing. The method assembles the catheter apparatus such that the capsule and the capsule bearing are configured to rotate together relative to the shaft and the shaft bearing.

[0098] Aspect 30. The method of Aspect 29, wherein attaching the proximal end portion of the capsule to the distal end portion of a capsule bearing comprises positioning the distal end portion of the capsule bearing within an inner passage of the proximal end portion of the capsule.

[0099] Aspect 31. The method of any one of Aspects 29-30, wherein attaching the proximal end portion of the capsule to the distal end portion of the capsule bearing comprises welding the proximal end portion of the capsule to the distal end portion of the capsule bearing.

[00100] Aspect 32. The method of any one of Aspects 29-31, wherein attaching the distal end portion of the shaft to the shaft bearing comprises attaching an attachment sleeve to the distal end portion of the shaft and attaching the attachment sleeve to the shaft bearing.

[00101] Aspect 33. The method of Aspect 32, wherein attaching the distal end portion of the shaft to the shaft bearing with the attachment sleeve comprises inserting an outer cylindrical surface of the shaft bearing into a cylindrical portion of the attachment sleeve and inserting an outer circumferential surface of the shaft into a proximally tapered portion of the attachment sleeve extending from the cylindrical portion of the attachment sleeve.

[00102] Aspect 34. The method of Aspect 33, wherein attaching the distal end portion of the shaft to the shaft bearing with the attachment sleeve comprises welding the proximally tapered portion of the attachment sleeve to the outer circumferential surface of the shaft and welding the cylindrical portion of the attachment sleeve to the shaft bearing.

[00103] Aspect 35. The method of any one of Aspects 39-34, wherein attaching the distal end portion of the shaft to the shaft bearing axially spaces a distal end of the distal end portion of the shaft from a proximal end of the capsule bearing. The capsule bearing is configured to rotate relative to the shaft without the proximal end of the capsule bearing contacting the distal end of the distal end portion of the shaft.

[00104] Aspect 36. The method of any one of Aspects 29-34, wherein rotatably attaching the capsule bearing to the shaft bearing further comprises positioning a collar of the capsule bearing within an inner circumferential recess of the shaft bearing.

[00105] Aspect 37. The method of Aspect 36, wherein positioning the collar of the capsule bearing within the inner circumferential recess of the shaft bearing comprises attaching a first portion of the shaft bearing to a second portion of the shaft bearing.

[00106] Aspect 38. The method of Aspect 37, wherein attaching the first portion of the shaft bearing to the second portion of the shaft bearing occurs along a plane that is perpendicular to the rotational axis of the capsule bearing.

[00107] Aspect 39. The method of any one of Aspects 29-38, wherein the distal end portion of the capsule bearing comprises a ring. The method further comprises inserting a segment of a sleeve of the capsule bearing into an interior area of the ring, and attaching the ring to the sleeve of the capsule bearing. An outer circumferential surface of the sleeve of the capsule bearing defines a circumferential base of the outer circumferential recess of the capsule bearing.

[00108] Aspect 40. The method of Aspect 39, wherein a distal end of the ring is welded to a distal end of the sleeve of the capsule bearing to attach the ring to the sleeve of the capsule bearing.

[00109] Aspect 41. The method of Aspect 37, wherein attaching the first portion of the shaft bearing to the second portion of the shaft bearing occurs along at least one plane that is coincident or parallel with the rotational axis of the capsule bearing.

[00110] Aspect 42. The method of any one of Aspects 37-41, wherein attaching the first portion of the shaft bearing to the second portion of the shaft bearing comprises welding the first portion of the shaft bearing to the second portion of the shaft bearing.

[00111] Aspect 43. The method of any one of Aspects 29-42, wherein the capsule bearing comprises an inner passage extending from a proximal opening at a proximal end of the proximal end portion of the capsule bearing to a distal opening at a distal end of the distal end portion of the capsule bearing. The method further comprises inserting a distal end of a torque coil through the proximal opening and into the inner passage of the capsule bearing. The method further comprises continuing to insert the distal end of the torque coil toward the distal opening until the distal end of the torque coil abuts a protrusion that prevents the distal end of the torque coil from exiting the distal opening of the capsule bearing.

[00112] Aspect 44. The method of Aspect 43, further comprising, fixedly attaching the torque coil to the capsule bearing after the distal end of the torque coil is abutted against the protrusion.

[00113] Aspect 45. The method of any one of Aspects 43-44, wherein the protrusion comprises an inwardly extending circumferential flange.

[00114] Aspect 46. The method of any one of Aspects 43-45, wherein the distal end portion of the capsule bearing comprises the protrusion.

[00115] Aspect 47. The method of any one of Aspects 43-46, wherein the protrusion at least partially defines the distal opening to prevent insertion of the distal end of the torque coil into the distal opening.

[00116] Aspect 48. The method of any one of Aspects 43-47, wherein the protrusion comprises an inwardly extending circumferential flange comprising a circular inner edge that circumscribes the rotational axis of the capsule bearing. The torque coil comprises an inner surface defining a coil lumen, and the inner surface of the torque coil defines a circular opening into the coil lumen at the distal end of the torque coil. The abutting the distal end of the torque coil with the protrusion aligns the inner surface of the torque coil to be substantially flush with the circular inner edge of the inwardly extending circumferential flange.

[00117] Aspect 49. The method of Aspect 48, further comprising butt welding the distal end of the torque coil to the inwardly extending circumferential flange while the inner surface of the torque coil is substantially flush with the circular inner edge of the inwardly extending circumferential flange and while the distal end of the torque coil abuts the protrusion.

[00118] Aspect 50. The method of any one of Aspects 48-49, wherein the circular inner edge of the inwardly extending circumferential flange defines the distal opening of the capsule bearing.

[00119] It should be understood that while various aspects have been described in detail relative to certain illustrative and specific examples thereof, the present disclosure should not be considered limited to such, as numerous modifications and combinations of the disclosed features are possible without departing from the scope of the following claims.

Claims

What is claimed is:

1. A catheter apparatus (101) comprising: a capsule (111) comprising a proximal end portion (125); a capsule bearing (305, 805) comprising a proximal end portion (307a, 807a) comprising a collar (313, 813), a distal end portion (307b, 807b) attached to the proximal end portion (125) of the capsule (111), and an outer circumferential recess (311, 811) defined between the distal end portion (307b, 807b) and the collar (313, 813); a shaft bearing (315, 815, 1115) comprising an inner circumferential surface (317, 817, 1117) received within the outer circumferential recess (311, 811), wherein the capsule bearing (305, 805) is configured to rotate relative to the shaft bearing (315, 815, 1115) about a rotational axis (303, 803) of the capsule bearing (305, 805), and a relative axial movement between the capsule bearing (305, 805) and the shaft bearing (315, 815, 1115) in a direction (304, 804) of the rotational axis (303, 803) is limited; and a shaft (103) comprising a distal end portion (109) attached to the shaft bearing (315, 815, 1115), wherein the capsule (111) and the capsule bearing (305, 805) are configured to rotate together about the rotational axis (303, 803) relative to the shaft (103) and the shaft bearing (315, 815, 1115).

2. The catheter apparatus (101) of claim 1, wherein the distal end portion (109) of the shaft (103) is axially spaced from the proximal end portion (307a, 807a) of the capsule bearing (305, 805) in the direction (304, 804) of the rotational axis (303, 803), wherein the capsule bearing (305, 805) is configured to rotate about the rotational axis (303, 803) relative to the shaft bearing (315, 815, 1115) without the proximal end portion (307a, 807a) of the capsule bearing (305, 805) contacting the distal end portion (109) of the shaft (103).

3. The catheter apparatus (101) of any one of claims 1-2, wherein the shaft bearing (815, 1115) comprises an inner circumferential recess (825, 1125) rotatably receiving the collar (313, 813) of the capsule bearing (305, 805).

4. The catheter apparatus (101) of any one of claims 1-3, further comprising a torque coil (135) extending through a lumen (106) of the shaft (103), and a distal end (137) of the torque coil (135) is positioned within an inner passage (402, 802) of the capsule bearing (305, 805), wherein the inner passage (402, 802) of the capsule bearing (305, 805) extends from a proximal opening (406a, 806a) at a proximal end (408a, 808a) of the proximal end portion (307a, 807a) of the capsule bearing (305, 805) to a distal opening (406b, 806b) at a distal end (408b, 808b) of the distal end portion (307b, 807b) of the capsule bearing (305, 805), wherein the inner passage (402, 802) of the capsule bearing (305, 805) is dimensioned to prevent a movement of the distal end (137) of the torque coil (135) through the inner passage (402, 802) of the capsule bearing (305, 805) during assembly.

5. The catheter apparatus (101) of claim 4, wherein the capsule bearing (305, 805) comprises a protrusion (330, 830) extending into the inner passage (402, 802) that dimensions the inner passage (402, 802) to prevent the movement of the distal end (137) of the torque coil (135) past the protrusion (330, 830) during assembly.

6. The catheter apparatus (101) of claim 5, wherein the protrusion (330, 830) comprises an inwardly extending circumferential flange that circumscribes the rotational axis (303, 803) of the capsule bearing (305, 805).

7. The catheter apparatus (101) of claim 6, wherein the inwardly extending circumferential flange comprises a circular inner edge (331, 831) facing the rotational axis (303, 803) of the capsule bearing (305, 805).

8. The catheter apparatus (101) of claim 7, wherein the circular inner edge (331, 831) of the inwardly extending circumferential flange defines the distal opening (406b, 806b) of the capsule bearing (305, 805).

9. The catheter apparatus (101) of any one of claims 7-8, wherein the torque coil (135) comprises an inner surface (139) defining a coil lumen (141), the inner surface at the distal end (137) of the torque coil (135), and a diameter of the circular opening (143) of the torque coil (135) is substantially equal to a diameter of the circular inner edge (331, 831) of the inwardly extending circumferential flange.

10. A method of assembling a catheter apparatus (101) comprising: rotatably attaching a capsule bearing (305, 805) to a shaft bearing (315, 815, 1115) comprising positioning an inner circumferential surface (317, 817, 1117) of the shaft bearing (315, 815, 1115) within an outer circumferential recess (311 , 811 ) of the capsule bearing (305, 805), wherein the capsule bearing (305, 805) comprises a proximal end portion (307a, 807a) and a distal end portion (307b, 807b), the capsule bearing (305, 805) is rotatable relative to the shaft bearing (315, 815, 1115) about a rotational axis (303, 803) of the capsule bearing (305, 805), and an axial movement of the capsule bearing (305, 805) relative to the shaft bearing (315, 815, 1115) in a direction (304, 804) of the rotational axis (303, 803) is limited; attaching a proximal end portion (125) of a capsule (111) to the distal end portion (307b, 807b) of the capsule bearing (305, 805); and attaching a distal end portion (109) of a shaft (103) to the shaft bearing (315, 815, 1115), wherein the capsule (111) and the capsule bearing (305, 805) are configured to rotate together relative to the shaft (103) and the shaft bearing (315, 815, 1115).

11. The method of claim 10, wherein attaching the distal end portion (109) of the shaft (103) to the shaft bearing (315, 815, 1115) axially spaces the distal end portion (109) of the shaft (103) from the proximal end portion (307a, 807a) of the capsule bearing (305, 805), wherein the capsule bearing (305, 805) is configured to rotate relative to the shaft (103) without the proximal end portion (307a, 807a) of the capsule bearing (305, 805) contacting the distal end portion (109) of the shaft (103).

12. The method of any one of claims 10-11, wherein the capsule bearing (305, 805) comprises an inner passage (402, 802) extending from a proximal opening (406a, 806a) at a proximal end (408a, 808a) of the proximal end portion (307a, 807a) of the capsule bearing (305, 805) to a distal opening (406b, 806b) at a distal end (408b, 808b) of the distal end portion (307b, 807b) of the capsule bearing (305, 805), the method further comprising inserting a distal end (137) of a torque coil (135) through the proximal opening (406a, 806a) and into the inner passage (402, 802) of the capsule bearing (305, 805), and continuing to insert the distal end (137) of the torque coil (135) toward the distal opening (406b, 806b) until the distal end (137) of the torque coil (135) abuts a protrusion (330, 830) that prevents the distal end (137) of the torque coil (135) from exiting the distal opening (406b, 806b) of the capsule bearing (305, 805).

13. The method of claim 12, wherein the protrusion (330, 830) comprises an inwardly extending circumferential flange comprising a circular inner edge (331, 831) that circumscribes the rotational axis (303, 803) of the capsule bearing (305, 805), wherein the torque coil (135) comprises an inner surface (139) defining a coil lumen (141), the inner surface (139) of the torque coil (135) defining a circular opening (143) into the coil lumen (141) at the distal end (137) of the torque coil (135), wherein abutting the distal end (137) of the torque coil (135) with the protrusion (330, 830) aligns the inner surface (139) of the torque coil (135) to be substantially flush with the circular inner edge (331, 831) of the inwardly extending circumferential flange.

14. The method of claim 13, further comprising butt welding the distal end (137) of the torque coil (135) to the inwardly extending circumferential flange while the inner surface (139) of the torque coil (135) is substantially flush with the circular inner edge (331, 831) of the inwardly extending circumferential flange and while the distal end (137) of the torque coil (135) abuts the protrusion (330, 830).

15. The method of any one of claims 13-14, wherein the circular inner edge (331, 831) of the inwardly extending circumferential flange defines the distal opening (406b, 806b) of the capsule bearing (305, 805).