Patent Application
20170224956
This disclosure relates to elongate medical devices such as sheaths, catheters, scopes, and the like that are configured for medical clinical use, and specifically where it is desired for a portion of the elongate medical device to follow along a curve to match a portion of the anatomy through which the device is desired to be extended, as well as to allow the catheter to deflect in order for the distal tip to be directed in a specific desired direction or orientation, such as to allow for observing or interacting with different parts of the anatomy.
A first representative embodiment of the disclosure is provided. The embodiment includes an elongate catheter. The elongate catheter includes an elongate sheath extending between a distal end portion and a proximal end portion, and a first lumen that extends though the sheath between the distal end portion and the proximal end portion. The distal end portion is configured to be repositionable between a first configuration where the distal end portion extends along a longitudinal axis that extends through the proximal end portion, and a first arcuate configuration where the distal end portion curves arcuately away from the longitudinal axis. The distal end portion comprises a plurality of rigid segments that are disposed in series and in a consistent orientation therealong and within the sheath, the plurality of rigid segments each include a top edge and a bottom edge and an inner cavity disposed therethrough, wherein the plurality of rigid segments are disposed such that the top edge of a second rigid segment of the plurality of rigid segments is disposed below the bottom edge of a first rigid segment of the plurality of rigid segments, wherein the first rigid segment is disposed closer to a distal tip of the catheter than the second rigid segment, and wherein the first lumen extends through the inner cavity of each of the plurality of rigid segments. The catheter further comprises a first wire disposed through the sheath and fixed with respect to a distal tip of the catheter, the first wire extending outboard of each of the plurality of rigid segments, wherein the catheter is configured such that a proximal longitudinal force applied to the first wire urges the distal end portion toward the first arcuate configuration, wherein two or more neighboring rigid segments pivot with respect to each other as the distal end repositions between the first orientation and the first arcuate configuration.
Another representative embodiment of the disclosure is provided. The embodiment includes a method of constructing an elongate catheter. The method includes the steps of forming a lumen that extends from a distal end portion to a proximal end portion, the distal end portion comprising a distal tip portion at a distal end of the distal end portion. The method includes the step of sliding a plurality of rigid segments over the lumen along a portion of the length of the lumen proximate to and proximal of the distal tip portion, and disposing the plurality of rigid segments in close proximity to each other such that a top edge of a second segment of the plurality of rigid segments is proximate to and facing a bottom edge of a first segment of the plurality of rigid segments, disposing a sleeve around the plurality of rigid segments. The method includes the step of aligning a wire from the distal end portion of the inner catheter and to a proximal tip of the proximal end portion of the inner catheter, the wire disposed outboard of each of the plurality of rigid segments. The method includes the steps of disposing an outer sheath around the sleeve and the wire. The method includes the steps of fixing a distal portion of the wire with respect to the distal tip portion of the inner catheter.
Advantages of the present disclosure will become more apparent to those skilled in the art from the following description of the preferred embodiments of the disclosure that have been shown and described by way of illustration. As will be realized, the disclosed subject matter is capable of other and different embodiments, and its details are capable of modification in various respects. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
Turning now to
The catheter may extend from a distal tip 15 to a proximal end portion 14. The proximal end portion 14 may include one or more hubs (not shown) that provide convenient portions for accessing or connecting to one or more of the various lumens, discussed below, through the catheter 10, as well as the interacting with other operable portions of the catheter. For example, the catheter 10 may include one or more optical lenses or sensors at or proximate to the distal tip 13, and the catheter may include an output connector or port to allow for interaction with the optical lenses or sensors, such as through an optical fiber or via other communication from the lens or sensor, such as an eye piece for direct viewing, or a connector to pass signal from the optical lens or sensor to a remote viewing means, such as TV or monitor, computer, or the like. Ports may additionally be provided to allow for flushing, suction, illumination, etc. through the catheter 10 and at a location proximate to the distal tip (and/or proximate to another portion of the catheter). Ports may also be provided to allow tools to be provided through one or more lumens of the catheter for use at a location proximate to the distal tip (or another location), such as laser fibers, baskets, forceps, needles, or the like. A schematic cross-sectional view of a potential proximal end portion 14 is depicted in
An end view of the distal tip portion 15 is depicted in
As mentioned herein, the distal ends of the one or more pull wires 53, 55 are fixed with respect to the distal tip portion 15, either fixed directly to the distal tip portion, or fixed to a fastener that is aligned with the distal tip portion. In one embodiment depicted in
As depicted in
The catheter 10 includes a sheath 20 that extends between the distal tip portion 15, through the distal end portion 12, and through the proximal end portion 14. The sheath 20 provides the outer surface of the catheter 10 and is formed from a strong and flexible material.
In some embodiments, the sheath 20 may include multiple coaxial layers, including an outer layer, as well as a woven layer 28 that extends along the entire or a portion of the length of the catheter. The woven layer 28 may consist of braided filaments of Stainless Steel or other medical grade metals, or polymer filaments. The woven layer may be beneficial to provide for added torqueability along the length of the sheath, i.e. to allow a rotation of the proximal end portion 14 of the catheter to transmit the rotational force to the distal tip, rather than causing the catheter to significantly twist along its axis. The woven layer 28 may be formed from a woven mesh, or braid that is formed as a tube and attached to the outer layer of the sheath, such as via co-extrusion of the woven layer with the outer layer. The sheath 20 may be formed separately from the body of the catheter and slid onto the body after the body has been assembled, and retained longitudinally and rotationally in place upon the body, such as by heat shrink lamination, otherwise known as heat shrunk, mechanically crimping, adhesive, or via other methods.
The catheter 10 includes a proximal end portion 14, a distal end portion 12, and a distal tip portion 15. The proximal end portion 14 may be a generally elongate portion that is formed with one or more lumens extending therethrough, as discussed below, and extends from the distal end portion 12 to the hubs (discussed above) at the proximal end of the catheter. The proximal end portion 14 may be configured to extend in a relatively straight orientation along its length with a longitudinal axis 1001 extending therethrough. The proximal end portion 14 may be flexible such that the proximal end portion 14 may be curved at one or more portions along its length without kinking the outer surface or any of the lumens that are disposed through the proximal end portion 14. The proximal end portion 14 may additionally include a steering mechanism that is manipulated by the user to urge the distal end portion 12 to translate between an elongate, relatively straight configuration and an arcuate configuration, discussed above. The proximal end portion 14 may include lumens to allow pull wires, or other structures, to pass therethrough such that the manipulation of the pull wires causes movement of the distal end portion 12 as desired, and the proximal end portion 14 may include one or more mechanisms to allow the user to control the motion of the distal end portion remotely from the proximal end portion 14. The term “wire” is used in this specification and claims for the sake convenience. One of ordinary skill in the art will understand that the term “wire” can include any elongate structure that is capable of being pulled in tension without any substantial elongation, and includes, a metal wire, a chain, a rope, a suture, a flexible cannula, or the like.
The proximal end portion 14 is stiffer than the distal end portion 12 of the catheter such that, as the as the pull wires 53, 55 of the catheter 10 are pulled proximally, the distal end portion 12 curves away from the longitudinal axis 1001 of the proximal end portion 14, while the proximal end portion is maintained relatively straight and aligned with the longitudinal axis.
The distal end portion 12 extends from the proximal end portion 12 to the distal tip 15. As discussed in further detail below, the distal end portion 14 is repositionable between a first configuration (
The distal end portion 12 of the catheter includes a single lumen 40, or in other embodiments two or more lumens 40, 42 that are configured to allow tools or devices to pass through and ultimately to and through apertures in the distal tip portion 15 of the catheter. In addition to lumens for tools, the distal end portion 12 may include dedicated lumens for aspiration/suction, a fiber optic line or visual data transfer, and in some embodiments a dedicated lumen for each pull wire 53, 55, discussed below.
The catheter 10 may include one or more pull wires 53, 55 that extend along the length of the catheter from the proximal end portion 14 and through the distal end portion 12. In some embodiments, distal ends of the pull wires 53, 55 may be fixed to the distal tip portion 15 of the catheter, while in other embodiments, distal ends of the pull wires 53, 55 may be fixed to the distal end portion 12 of the catheter. In embodiments where a single pull wire 53 is provided, the distal end portion 12 of the catheter can bend in a single direction away from the straight configuration when the pull wire 53 is manipulated. In other embodiments where two pull wires 53, 55 are provided, normally on opposite sides of the catheter, the distal end portion 12 can bend in two opposite directions when the opposite pull wires 535, 55 are manipulated. In other embodiments three or more pull wires may be provided. In these embodiments, the pull wires may be provided in pairs that are disposed on opposite sides of the plurality of rigid segments 60, as discussed below. For example,
As best shown in
In some embodiments, each of the rigid segments 60 may be formed with the same geometry, while in other embodiments, each of the rigid segments may be formed with the same cross-sectional profile, but may be formed with differing heights. As discussed below, providing rigid segments 60 with differing heights may allow for the distal end portion 12 to bend at different curvatures. For example, a portion of the distal end portion 12 with rigid segments that are relatively shorter than a second portion of the distal end portion 12 that have rigid segments 60 that are longer is able to curve at a larger angle, because the bending occurs at the intersection 130 (
In some embodiments, the profile of the top and bottom edges 72, 82 may be the same for all rigid segments 60, while in other embodiments, the profile of the top and bottom edges 72, 82 may be different, such as with a different depth for the concave portion 74, 84 upon the top and/or bottom edges 72, 82 of different rigid segments. As discussed below and as depicted in
In some embodiments, the rigid segments each include a single concave portion 74, 84 on the respective top and bottom edges 72, 82, while in other embodiments each rigid segment 60 includes two concave portions 74, 84 on each respective edge. In some embodiments, the concave portions 74, 84 are disposed on opposite sides of each rigid segment 60, while in other embodiments, the concave portions may be disposed at different relative locations with respect to each other, such as 90 degrees to each other (in embodiments where it is desired to allow the catheter to curve with respect to the longitudinal axis in two directions that are perpendicular to each other. For the sake of simplicity, the position of the two concave portions on opposite sides of the rigid segment 60 from each other, while one of ordinary skill will understand that the concave portions can be positioned at different relative positions with a thorough review and understanding of the subject specification and figures. In some embodiments, three or more concave portions may be provided, with the concave portions evenly distributed about the circumference of the rigid segment, or at other desired spacing relationships.
The top edge 72 and the bottom edge 82 of each rigid segment 60 additionally includes two or more end portions 76, 86 that are disposed between or adjacent to the concave portions 74, 84. In embodiments where the rigid segments 60 include two concave portions 74, 84 on the respective top and bottom edges 72, 82, the end portions 76, 86 are disposed to contact an end of each concave portion. The end portions 76, 86 may include center portions 76a, 86a that extend to the highest (and lowest) longitudinal positions of the edge portions 76, 86. The center portions 76a, 86a may be positioned substantially perpendicular to the longitudinal axis 1002 through the open cavity 69 and parallel to the side walls. The end portions 76, 86 may be curved along their length, with the curve extending through the center portions 76a, 86a. The end portions 76, 86 may be curved along their length with a curve arranged such that adjacent rigid segments 60 have rolling, and in some embodiments continuous contact as the rigid segments 60 pivot with respect to each other. In some embodiments, the end portions 76, 86 may curve toward the concave portions 74, 84 and may be include continuous curvature therebetween. In embodiments where the top and bottom edges 72, 82 each only include a single concave portion 74, 84, the end portion 76, 86 may wrap around a significant portion of the top edge and bottom edge 72, 82, i.e. for example around about between 200 to 270 degrees of the circumference of the rigid segment, with the concave portion around about 45 to 90 degrees of the circumference, and in some embodiments curved portions 76b, 86b disposed between the center portions 76a, 86a and the concave portion 74, 84.
In some embodiments depicted in
b are detail views of a rigid segment 60, which is configured to allow two lumens 44, 46 to pass through. The lumens, each have a radius of variable R (diameter X) (specifically, when referring to lumens 44, 46 in this context, the radius includes the radius of the lumen 44 itself as well as the wall thickness of the wall of the cannula or tube (40, 42 that forms the lumen, now shown in
In one representative embodiment, the rigid elements 60 may be constructed with a wall thickness of 0.010 inches, and an outer diameter of 0.096 inches (in an embodiment where the rigid elements 60 are cylindrical). The top and bottom edges 72, 86 may be formed with a curvature with a radius of 0.1 inches along its length, or through the center portions 76a, 86a of the end portions 76, 86 and through a portion end portions 76, 86 as the end portions extend toward the concave portions 74, 84. The height of the rigid segments 60 may be 0.01 inches, with the scallop being 0.012 inches (e.g. the vertical distance between the height at the center portion 76a to the lowest point of the concave portion. One of ordinary skill in the art will understand that in some embodiments, the dimensions of the rigid elements (and the remainder of the catheter) may be scaled upward or downward as desired, with limitations due to manufacturability and strength on the low end, and limitations based upon size and weight on the upper end. The specific sizing of components will be readily understood by one of ordinary skill in the art upon a thorough review of the subject specification.
As depicted in
In some embodiments as shown in
As depicted in
A possible method of manufacture of the catheter 10 discussed herein is provided, and can be understood with reference to
Next, in embodiments where the lumens in the proximal end portions are formed without cannula, cannula may be connected to each lumen and extend distally from the lumens at the distal end of the proximal end portion. Alternatively, a body that forms the inner lumens 44, 46 through the distal end portion can be formed (using known techniques) and is aligned with the distal end of the proximal end portion 14, such that the lumens are aligned through the distal end portion 12, and the proximal end portion 14.
Next, a plurality of rigid segments 60 are threaded over the lumens (i.e. the cannula e.g. 40, 44 defining the lumens, or the body of defining the lumens) until the proximal most rigid segments rests upon the distal end of the proximal end portion 14. Additional rigid segments 60 are then individually threaded until all of the desired rigid segments 60 have been threaded. In some embodiments, the rigid segments 60 may be allowed to contact each other at the respective top and bottom edges 72, 82 of the neighboring adjacent rigid segments 60, and specifically the end portions 76, 86 of the those edges. In other embodiments, some or all of the neighboring adjacent rigid segments 60 may be maintained at a spaced relationship from each other, and tooling may be provided, such a comb-like structure with legs that extend between adjacent segments 60 to maintain the spacing. The rigid segments 60 are aligned such that each of the first concave segments 74, 84 (upon the respective top and bottom edges 72, 82) are aligned facing the concave segment on the opposite edge of the adjacent rigid segment, with the first concave segments 74, 84 all in radial alignment with each other along the length of the distal end portion 12. In embodiments, where the top and bottom edges 72, 82 include two or more concave surfaces, then the rigid segments are aligned such that the all of the second concave surfaces 74, 84 (as well as further additional concave surfaces) on the respective top and bottom edges 72, 82 are also in radial alignment and facing each other and in closely adjacent each other.
When all of the desired rigid segments 60 have been threaded over the lumens, a sleeve 68 is threaded over the desired rigid segments 60 and when in place may be fixed to the outer surface of all of the rigid elements 60 (such as by heat shrinking or adhesive, or the like) to closely fit with an maintain the desired longitudinal alignment between neighboring adjacent rigid segments 60. Alternatively, a sheet may be wrapped around the rigid segments 60 and fixed along a seam to form a sleeve, and then heat shrunk or otherwise fixed to the rigid segments 60 to maintain alignment therewith.
Next, a distal tip 15 is fixed to the distal end of the distal end portion 12. The distal tip 15 is aligned such that the appropriate lenses and apertures on the distal tip are aligned with the lumens that extend through the distal end portion 12 and the proximal end portion 14, such as to align a lens on the distal tip with a light fiber or sensor that is provided to view an image proximate to the distal tip 15 of the catheter, and apertures are provided to allow tools and the like (as well as fluids, gas, or suction) items to pass from the lumens and therethrough.
Next, one or more pull wires 53, 55 are fixed with respect to the distal tip 15, such as directly to the distal tip, or to structure within the distal end portion 12 (e.g. to the distal most rigid segment 60) and threaded through the distal end portion 12, and proximal end portion 14 so that it/they may be manipulated by the user from the proximal end portion 14, normally outside of the patient. The pull wires 53, 55 may be threaded through cannula (e.g. 50, 54) or lumens formed in the body of the catheter, or through a combination of the two.
Next an outer sheath is disposed around the length of the catheter 10, at least along the distal end portion 12, and the proximal end portions 14. The outer sheath 20 maybe heat shrunk or otherwise fixed to the components of the distal end portion 12 and/or to the proximal end portion 14.
While the preferred embodiments of the disclosure have been described, it should be understood that the disclosure is not so limited and modifications may be made without departing from the disclosure. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
This application claims priority from U.S. Provisional Application No. 62/293,549, filed on Feb. 10, 2016, the entirety of which is hereby fully incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62293549 | Feb 2016 | US |
