The present invention relates to the field of surgery and more particularly, to articulating surgical devices and methods of accessing targeted tissue using an articulating device.
This invention pertains to an articulating arthroscopic or endoscopic device. In arthroscopy, the number of portals through the patient's skin are kept to a minimum to reduce patient scarring and improve speed of patient recovery. The locations may not be preferable for accessing all portions of the tissue to be treated within the joint and therefore some devices may be selectively articulable or have a pre-bent or angled end. Portals are preferably limited in size using a 5.0 mm cannula however, restricting the ability for a pre-bent device to be inserted therethrough. This restriction to a smaller cannula size also tends to compromise rigidity of an articulated shaft and typical articulating shafts may flex and not hold their shape when in contact with tissue. The surgeon therefore may have to use a fixed device for treating a tissue in one mode such as bulk tissue removal that may do much of the heavy lifting, and articulating devices may be brought in for precise tissue removal or removal in locations that could not be reached with a fixed device. Therefore, there is a need for a device that may articulate and be sufficiently rigid to hold its shape during use.
Articulating portions of these shafts may include a plurality of transverse cuts or cutouts through the shaft(s) and arranged along at least a portion of the length of the shaft(s). These cutouts may expand and contract during articulation. In some applications, the plurality of cutouts may be covered by a thin and flexible sheath. Sheath may electrically isolate a portion of the shaft for energy-based devices for example. An example of a device distal end 100 with a sheath 120 may be seen in
For a detailed description of example embodiments, reference will now be made to the accompanying drawings in which:
Generally, this disclosure describes a surgical device having an articulating tubular member with cuts or slots therethrough, configured to direct articulation. The device may be sized to fit down a 5.0 mm cannula, and articulate to enable access to joint anatomies. Articulation may be achieved by a flexible portion including at least one cutout that is configured to provide improved shaft bending strength and torsional rigidity when in the fully articulated configuration compared to other articulating devices.
This disclosure also describes an articulating surgical device that includes a thin flexible sheath covering at least some of the cutouts. A sleeve liner that may include angular cuts may be coaxially disposed over the cutouts to limit migration of the thin flexible sheath into the radial cutouts during articulation. The liner may define a thin-walled, high melting point tubing that fits between the insulation sheath and metallic shaft that stretches or slides when the device articulates. The surgical device may be an RF device wherein the tubular member may be electrically coupled as an electrode and wherein the sheath limits exposure of the tubular external surface and thereby the electrode location and size.
A first example embodiment of a surgical instrument may include a handle and an elongate shaft assembly extending distally from the handle. The elongate shaft has a longitudinal axis. The elongated shaft assembly is articulable between a fully flexed configuration and a lesser flexed configuration. The elongated shaft assembly includes a tubular member including a flexible or articulable portion with a first preferential bending direction. There is also an elongate member coaxially disposed within the tubular member and directly coupled to the tubular member at a location distal the flexible portion. Axial tension on the elongate member may articulate the shaft assembly. The flexible portion is defined by a plurality of cutouts, through the thickness of the tubular member. Each cutout defines a cutout longitudinal axis. Each cutout includes a tapered opening portion defined by a pair of linear edges facing each other. Linear edges may be defined by which side of the cutout they are located. For example, the pair of linear edges may be termed a proximal linear edge and a distal linear edge. At least one of the plurality of cutouts define an asymmetrical shape about its corresponding cutout longitudinal axis, the asymmetric shape configured to increase a circumferential length of contact between the pair of linear edges, when the flexible portion is in the fully flexed configuration.
In some embodiments, at least one of the cutouts defines a keyhole shape with a bulbous closed end, the bulbous closed end asymmetrical about its cutout longitudinal axis. The bulbous closed end may define a proximal concave surface and a distal concave surface, which are continuous with each other, and wherein the distal concave surface defines a tighter radius of curvature than the proximal concave surface. The bulbous closed end may define a maximum axial width that is less than 50% larger than a maximum axial length of tapered opening portion when the instrument is in a lesser flexed configuration. In the fully flexed configuration, the proximal linear edge and distal linear edge of each of the plurality of cutouts may align with each other to form a smooth curved shaft surface, free of terracing. The cutout asymmetrical shape may be configured to rotate the distal edge towards the proximal edge so that they align once engaged. The plurality of cutouts tapered opening portions each define an angular opening when the shaft is in a less articulated configuration, and in a neutral or non-articulated configuration a distal-most cutout of the plurality of cutouts has a smaller angular opening than all of the remaining plurality of cutouts.
Another embodiment of a surgical instrument disclosed herein may include a handle and an elongate shaft assembly extending distally from the handle. The elongated shaft assembly includes a tubular member including an articulable portion defined by at least one cutout through a wall of the tubular member. An elongate member is also coaxially located along the tubular member and coupled to the tubular member at a position distal to the articulable portion. Actuation of the elongate member flexes the articulable portion and angularly offsets a distal end of the tubular member relative to a proximal end of the elongate shaft. The at least one cutout defines a longitudinal axis transverse a shaft longitudinal axis, wherein the at least one cutout defines an asymmetrical shape about the cutout longitudinal axis. The asymmetrical shape is shaped to increase a length of circumferential contact between a proximal and distal circumferential edge of each cutout when the distal end is flexed at a maximum angular offset.
In some embodiments, the at least one cutout defines a keyhole shape with a bulbous closed end, the bulbous closed end defining a concave proximal surface and a concave distal surface facing the concave proximal surface and different in radius of curvature to the concave proximal surface. The concave proximal surface may define a larger radius of curvature than the concave distal surface. The asymmetrical shape may be configured to form a continuous uninterrupted curve along the articulable portion when the distal end is flexed at the maximum offset angle. The at least one cutout may comprise at least two cutouts, each of the at least two cutouts defining an angular opening and wherein when angular opening of the distal-most cutout of the at least two cutouts is formed with a smaller angular opening than all remaining cutouts.
Another example additional surgical instrument embodiment is disclosed herein, including a handle and an elongated shaft assembly extending distally from the handle. The elongate shaft assembly includes a tubular member having an articulable portion defined by a plurality of axially spaced cutouts through the tubular member. The elongate shaft assembly also includes a sheath, coaxial with the tubular member and covering the tubular member including covering the articulable portion. The elongate shaft member also includes a liner disposed between the sheath and tubular member, along the articulable portion. The liner includes at least one discontinuity through a thickness of the liner, configured to permit the articulable portion to articulate while concomitantly blocking migration of the sheath into the cutouts.
In some embodiments, the discontinuity may include a helical cut around and along a portion of the liner. The discontinuity may comprise a helical cut having an axial gap length, the axial gap length configured to increase liner flexibility while concomitantly blocking migration of the sheath into the radial cutouts. The axial gap length may be formed by axially stretching or extending the liner. The tubular member may be electrically conductive and the sheath may be an electrical insulator, configured to limit an exposed electrically conductive outer surface of the tubular member. The liner may be a Nylon sleeve. Substantially each revolution of the helical cut may occur within a respective distance along a length of the articulable portion including at least two of the plurality of cutouts. Substantially each revolution of the helical cut may occur within a respective distance along an axial length of the articulable portion so as to cover at least three of the plurality of radial cut outs.
An additional example embodiment is disclosed that may include a handle and an elongated shaft assembly extending distally from the handle. The elongated shaft assembly may include a tubular member with a flexible portion defined by a plurality of radial cutouts through the tubular member, axially spaced along the tubular member. The radial cutouts may open and close while flexing. The elongated shaft assembly may also include a sheath coaxial with the tubular member and covering the tubular member including covering the flexible portion. The elongated shaft assembly may also include a sleeve or liner coaxially disposed between the sheath and tubular member and along the flexible portion. A spiral cut may extend along and around a portion of the sleeve, the spiral cut and sleeve generally configured to permit the flexible portion of the tubular member to articulate, wherein the radial cutouts expand and contract while concomitantly limiting migration of the sheath into the radial cutouts.
In some example embodiments, the sleeve may be stretched or formed to include at least one elongate axial gap. This may be formed by stretching the sleeve such that the spiral cut edges move away from each other. The axial gap may be configured to increase sleeve flexibility while maintaining a block for migration of the sheath into the radial cutouts. In some example embodiments, the tubular member is electrically conductive and the sheath is an electrical insulator, configured to limit an exposed electrically conductive outer surface of the tubular member. In some example embodiments, the sleeve comprises Nylon. In some example embodiments, substantially each revolution of the spiral cut occurs within a respective distance along an axial length of the flexible portion of three of the plurality of radial cutouts. In some example embodiments substantially each revolution of the spiral cut occurs within a respective distance along an axial length of the flexible portion of two of the plurality of radial cut outs.
A further example embodiment of a surgical instrument may include a handle and an elongated shaft assembly extending distally from the handle. The elongated shaft assembly may include a tubular member having a flexible portion defined by a plurality of transverse cutouts through the tubular member, axially spaced along the tubular member. The elongated shaft assembly may also include a sheath coaxial with the tubular member and covering the flexible portion and a sleeve disposed between the sheath and tubular member and along the flexible portion. The sleeve may flex, stretch, and permit the flexible portion of the tubular member to articulate while concomitantly limiting migration of the sheath in between the transverse cutouts.
In some example embodiments, the tubular member may be electrically conductive and the sheath is an electrical insulator, configured to limit an exposed electrically conductive outer surface of the tubular member. In some example embodiments, the sleeve may define a thin-walled high temperature sleeve. In some example embodiments, the sleeve may include a plurality of incisions orientated at an angle to a longitudinal axis of the sleeve to increase flexibility of the sleeve while concomitantly limiting migration of the sheath in between the transverse cutouts. In some example embodiments, the sleeve may include a single elongate helical cut configured to increase flexibility of the sleeve while concomitantly limiting migration of the sheath in between the transverse cutouts. In some example embodiments each revolution of the single helical cut may occurs within a respective distance along a length of the flexible portion of three of the plurality of transverse cuts. In some example embodiments, each revolution of the helical cut occurs within a respective distance along the length of the flexible portion of two of the plurality of transverse cutouts. In some example embodiments, the helical cut may include axial openings to further increase flexibility of the sleeve while concomitantly limiting migration of the sheath in between the radial cutouts.
Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, companies that design and manufacture electrosurgical systems may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection or through an indirect connection via other devices and connections.
Reference to a singular item includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “an,” “said” and “the” include plural references unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement serves as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Lastly, it is to be appreciated that unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. “Ablation” shall mean removal of tissue based on tissue interaction with a plasma.
“Mode of ablation” shall refer to one or more characteristics of an ablation. Lack of ablation (i.e., a lack of plasma) shall not be considered an “ablation mode.”
“Active electrode” shall mean an electrode of an electrosurgical wand which produces an electrically-induced tissue-altering effect when brought into contact with, or close proximity to, a tissue targeted for treatment.
“Return electrode” shall mean an electrode of an electrosurgical wand which serves to provide a current flow path for electrical charges with respect to an active electrode, and/or an electrode of an electrical surgical wand which does not itself produce an electrically-induced tissue-altering effect on tissue targeted for treatment.
The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is
Before the present invention is described in detail, it is to be understood that this invention is not limited to particular variations set forth herein as various changes or modifications may be made to the invention described and equivalents may be substituted without departing from the spirit and scope of the invention. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the present invention. All such modifications are intended to be within the scope of the claims made herein.
Methods recited herein may be carried out in any order of the recited events, which is logically possible, as well as the recited order of events. Furthermore, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. In addition, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein.
All existing subject matter mentioned herein (e.g., publications, patents, patent applications and hardware) is incorporated by reference herein in its entirety except insofar as the subject matter may conflict with that of the present invention (in which case what is present herein shall prevail). The referenced items are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.
Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “an,” “said” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Last, it is to be appreciated that unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The inventors have recognized that it may be desirable to provide an articulable elongated shaft assembly with sufficient rigidity in an articulated configuration. Such rigidity may help to maintain a distal tip of the elongated shaft assembly in a desired position and/or orientation during a surgical procedure and/or avoid excessive deflection of the shaft assembly when a force is applied to the distal tip. For example, the distal tip may be pressed into contact with a surface when deploying a fastener into tissue, and the rigidity of the elongated shaft assembly may limit the deflection of the tip to be less than a desired threshold deflection for a predetermined force applied to the distal tip. As a further example the distal tip may be used to elevate or move tissue to gain better access and electrosurgically treat a target tissue, and the rigidity of the elongated shaft assembly may limit the deflection of the tip while elevating tissue.
As used herein, the term “distal direction” within a surgical device may refer to a direction that extends along a longitudinal axis of the surgical device towards a distal end of the surgical device where a desired operation is performed. Correspondingly, a “proximal direction” may refer to a direction that is directed in an opposite direction relative to the distal direction such that it may be directed along the longitudinal axis of the surgical device away from the surgical device's distal end where the desired operation is performed.
According to some embodiments, an elongated shaft assembly extends distally from a handle of a surgical instrument. The elongated shaft assembly includes an articulable portion that may articulate in at least one direction between a first position, which may correspond to a non-articulated configuration, to a second position, which may correspond to a fully articulated configuration in which the distal tip is oriented at an angle (e.g., an articulation angle) relative to a portion of the elongated shaft assembly located proximal to the articulable portion. When in the first position, a longitudinal axis passing through the articulable portion may be aligned with a longitudinal axis of the proximal portion of the elongated shaft assembly. Correspondingly, when in the fully articulated configuration, the distal tip of the elongated shaft assembly, and the longitudinal axis of the articulable portion, is oriented at an articulation angle relative to the longitudinal axis of the proximal portion. In the fully articulated configuration a substantial portion of the edges of cutouts along the device shaft are in contact with each other. In one embodiment, the articulation angle of the fully articulated configuration may be between 15 degrees and 90 degrees though it should be understood that the current disclosure is not limited to any particular range of articulation angles. Moreover, in some embodiments, the articulable portion may be movable to one or more additional articulated positions between the non-articulated (i.e., straight) configuration and the fully articulated configuration.
The surgical devices described herein may be made out of any desirable material or combination of materials. In some instances, the surgical devices described herein may be made from materials that are either sterilized and/or are sterilizable using any appropriate method including, but not limited to, heat, radiation, and/or pressure. Moreover, the materials may be capable of either being sterilized before, during, or after assembly and packaging to maintain sterility.
In some embodiments, a surgical instrument may include an elongated shaft assembly including a first articulating shaft and a second articulating shaft coaxially arranged relative to the first articulating shaft. The first and second articulating shafts may include flexible portions that form an articulable portion of the elongated shaft assembly, and the first and second articulating shafts are axially fixed relative to one another at a location distally located relative to the articulable portion. Proximal portions of the first and second articulating shafts may be axially displaceable relative to one another to move the articulable portion of the elongated shaft assembly between the first and second positions. For example, the proximal portions of the first and second articulating shafts may be displaced relative to one another to selectively place the first and second articulating shafts in opposing states of tension and/or compression. As discussed in more detail below, such tensile and/or compressive forces may be transmitted through a suitable structure in the articulable portion to apply and/or release a bending moment in the first and second articulating shafts, thereby moving the articulable portion between the non-articulated and articulated configurations. In some embodiments, the bending moment causes the articulable portion to move from the non-articulated configuration, which may correspond to a relaxed configuration of the elongated shaft assembly, to the articulated configuration. However, it should be understood that the current disclosure is not limited to embodiments in which a bending moment causes movement towards an articulated configuration. For example, in some embodiments, the fully articulated configuration may correspond to a relaxed (i.e., stress-free) state for the elongated shaft assembly, and application of a bending moment (or other suitable stresses) may cause the elongated shaft assembly to move toward the non-articulated (i.e., straight) configuration.
In some embodiments, a surgical instrument may include an articulation control operable by a user to selectively move an articulable portion of an elongated shaft assembly of the device between non-articulated and fully articulated configurations. The articulable portion of an elongated shaft assembly may be formed by one or more flexible portions of the associated shafts that permit articulation. For example, the flexible portions of the shafts may include a plurality of cutouts extending substantially in a transverse direction across a diameter of the shafts and arranged along at least a portion of the length of the various shafts comprising the elongated shaft assembly to provide a desired flexibility. It may be beneficial to provide a desired rigidity of the elongated shaft assembly while still permitting articulation of an articulable portion of the elongated shaft assembly. Accordingly, in some embodiments, the specific dimension and arrangement of the cuts, spines, and/or other suitable features of at least first articulating shaft of the elongated shaft assembly may be selected to provide the desired stiffness. In one embodiment, the spines may have a tapered configuration with distal portions of the spines being narrower than proximal portions thereof. This may provide an increased bending stiffness of the elongated shaft assembly at a proximal end of the spines and increased flexibility of the assembly at the distal end. Such a configuration may permit the distal end of the articulating shaft assembly to have enough flexibility to articulate to a desired articulated position while also becoming progressively stiffer at the proximal end of the articulable portion. Without being bound by theory, such a configuration may help to avoid undesired deflection of an elongated shaft assembly during use, for instance, when a user presses a distal end of the shaft assembly against a surface to deploy a fastener into tissue.
In addition to the above, the inventors have recognized that the number, size, and/or spacing of the cuts in the shafts of an articulable portion of an elongated shaft assembly may influence the resulting stiffness of the elongated shaft assembly in the non-articulated and/or articulated configurations. For example, the inventors have found that articulating shafts having increased numbers of cuts and smaller cut sizes in the articulable portion may provide for enhanced stiffness while still permitting a desired amount of articulation of the articulable portion. Accordingly, in some embodiments the number of cuts, the cut size, and/or cut spacing may be selected to provide a desired stiffness for the elongated shaft assembly. Specific sizings and spacings of the cuts are discussed in more detail below in regards to specific embodiments.
As noted above, an elongated shaft assembly may include first and second articulating shafts that are placed in opposing states of tension and compression when an articulable portion of the elongated shaft assembly is in an articulated configuration. In some embodiments, the articulating shaft that is placed in the compressive state may include a plurality of cuts that are sized and shaped such that opposing sides of each of the cuts come into contact with one another when the articulable portion is fully articulated. For example, the inventors have appreciated that such configurations may impart additional stability and/or rigidity to a distal portion of the elongated shaft assembly when in the articulated configuration.
Turning to the figures, specific non-limiting embodiments are described in further detail. It should be understood that the various systems, components, features, and methods described relative to these embodiments may be used either individually and/or in any desired combination as the disclosure is not limited to only the specific embodiments described herein.
The articulable portion 8 of the elongated shaft assembly may be moved between at least a first position, such as an unarticulated position, and second position, such as a fully articulated position, using articulation control 10. In this example, control 10 may be rotated around the longitudinal axis of the instrument 2. Depending on the embodiment, the articulable portion 8 may be moved to one or more preselected articulation angles, or the articulable portion 8 may be adjusted to one or more arbitrary (i.e. not preselected) articulation angles.
The elongated shaft assembly may include an inner shaft 32 and an outer shaft 34, the inner shaft 32 extending within the outer shaft 34. As described herein, the shafts (32, 34) are constructed and arranged to move the articulable portion 8 between the non-articulated position and the one or more articulated positions. Shafts (32, 34) of the elongated shaft assembly may be arranged coaxially relative to one another and both shafts may define an elongate lumen along their respective axes, at least along the articulable portion. Although a particular arrangement of shafts is shown in the figures, it should be understood that other arrangements also might be suitable. For example, in an alternative embodiment, the inner shaft 32 may be a flexible pull rod with no lumen or cutouts.
As illustrated, the articulable portion 8 may include a plurality of cutouts (40, 42), which define one or more spines extending along a length of the shafts (32, 34). Seen both in
The inner and outer shafts 32 and 34 may be attached to one another at an attachment point 62, which is preferably located distally from the articulable portion 8. This may axially fix the inner and outer shafts to one another at the attachment point 62. In the depicted embodiment, the attachment point 62 is located adjacent a distal end of the inner shaft 32, and the outer shaft may extend distally further than the inner shaft 32. The two shafts 32, 34 may be attached in any suitable manner, such as with an adhesive, one or more fasteners, one or more pins, one or more welds, and/or any other appropriate form of connection.
Due to the distal attachment 62 of the two shafts 32, 34, application of axial forces and/or displacements to corresponding proximal portions of the inner and outer shafts 32, 34 may place these shafts in a state of tension and/or compression. For example, a proximally directed force and displacement applied to a proximal portion of the inner articulating shaft 32 may create a tensile stress in the inner shaft 32. Similarly, application of a corresponding distally directed force and displacement to a proximal portion of the outer shaft 34 may create a compressive stress in the outer articulating shaft. These opposing tensile and compressive stresses may be transmitted through the opposing spines 44 and 46 of the respective shafts, which are both offset from a neutral bending axis of the overall elongated shaft assembly. This creates a bending moment in the articulating shafts, which causes the articulating shafts to bend and move the elongated shaft assembly toward an articulated position.
Proximally and distally directed forces and displacements may be applied to the shafts, respectively, via any suitable articulation control system. For example, a surgical instrument may include an articulation control 10 to selectively move an articulable portion 8 of an elongated shaft assembly between the non-articulated and articulated positions. Depending on the particular embodiment, the articulation control may be coupled to articulating shafts (32, 34) of the elongated shaft assembly via any suitable structure to control the articulation. For example, control 10 may be operatively coupled to the inner shaft 32, and actuation of the control 10 may axially retract the inner shaft 32 proximally, while the outer shaft 34 remains fixed and stationary.
Now moving on to
Each of the outer shaft cutouts 42 may define a keyhole shape having a longitudinal axis Lc transverse the longitudinal axis L of the shaft 34. The keyhole shape includes a tapered or angled opening portion 42a extending from the inner-side 35 and terminating with a rounded or bulbous closed end 42b. Closed end 42b may also be described as a kidney bean shaped end 42b. End 42b is configured to isolate the bending stress to one point within each cut 42. Angled opening portion 42a defines a linear tapered opening, tapering to a smaller opening as the opening portion 42a extends away from inner radial side 35 and towards the rounded end 42b. Keyhole shaped cutout 42 is not symmetrical about the longitudinal axis Lc. Keyhole shaped cutout 42 is not mirror image about a vertical plane normal to the instrument longitudinal axis L and extending along longitudinal axis Lc.
Angled opening 42a is defined by a distal edge 43a and proximal edge 43b that may be linear. Angled portion 42a may taper uniformly and may taper at angle θ that is split evenly either side of axis Lc. Angled opening defines a longer distal edge 43a than the proximal edge 43b. The distal edge length of tapered opening 42a may extend further in a direction traverse the longitudinal axis L and thereby remove a larger arc segment of the tubular shaft annular wall. For example, with reference to the view shown in
Each cutout 42 defines a maximum opening width D1 along the side 35, defined in the least articulated orientation, which may be a straight configuration. Rounded closed end 42b defines a maximum axial dimension D2. D2 may preferably be larger than Dl1 However, so as place a plurality of cutouts 42 in close succession, and evenly distribute the articulated curve along the curve length, D2 is preferably less than 50% greater than D1. As shown, D2 is approximately 30% larger than D1. For a shaft that is 0.20 inches in outer diameter, D2 may be approximately 0.052 inches, while D1 may be 0.04 inches for example.
As way of comparison,
Another key characteristic shown in
Furthermore, the angles (θ) of each cutout 42 may be different from each other. In some instances, there may be stress concentrations in the proximal-most and distal-most cutouts. Therefore the angle (θ) is the proximal-most and distal-most cutouts 42 may be smaller than the intermediate cutouts 42. The bend angle in those proximal-most and distal-most cutouts 42 is reduced and the middle cuts are widened to maintain the same overall bend angle of the shaft when fully articulated. Furthermore reducing the angle (θ) of the most distal cutout 42 is also useful because it can be difficult to fully close due to its proximity to the weld point 62. It is preferable that all of the cutouts must completely close when fully articulated to have edge on edge or in most cases metal on metal contact to maximize its torsional rigidity. Therefore, the plurality of cutouts are configured for a specific target bend angle of the fully articulated portion for maximum stiffness and torsion resistance. For example, these geometries were developed for shafts with maximum angles between 30 degrees and 70 degrees. A 30-40 degree shaft may mimic a fixed angle device, as described herein. The 70-degree shaft may be used as a continuously articulating device, meaning that the surgeon may often change the degree of articulation during use.
Returning to
In some embodiments, articulable portion 8 may also include a coiled or slotted liner 850, as shown in at least
As explained earlier, a sheath 120 over an articulable portion 8 may be required as part of the instrument's function, for example to electrically isolate a shaft and/or limit debris and ingress through the cut outs 842. However, the sheath 120 is preferably flexible to minimally influence articulation and this flexibility may inherently allow migration of the sheath 120 into the cutouts 842. Therefore, the inventors have developed a liner 850 for placing coaxially between the shaft 842 and sheath 120 to limit sheath migration. The liner is a thin sleeve to evade adding bulk or diameter to the device, and has a stiffness configured to resist migration of both itself and the sheath 120 into the cutouts 842. Making the liner stiffer to avoid migration however may hinder articulation as disclosed herein. Therefore, the liner 850 includes discontinuities in the form of slots or cuts through the liner thickness, configured to increase the liner's flexibility during articulation. Slots or cuts may be orientation to maintain a barrier to sheath migration into cutouts 842. Slots or cuts may be orientated at a non-zero angle to both a longitudinal axis and transverse axis of the liner 850. In some embodiments sheath may be a heat shrink, and therefore the process of shrinking sheath may naturally form sheath 120 to the shape and cuts along liner 850.
As shown in
While the inventors envision a range of spiral cut angles, widths and spacings, in order to reduce exposure to the cutouts 842, spiral cut 860 may preferably be defined by the axial distance along the liner 850 each full revolution the spiral cut 860 makes, which is indicated as distance W in
Advantageously this liner 250 may reduce migration of a sheath in an electrosurgical instrument wherein the electrical energy is insulated by a sheath along portions of the instrument. Instrument may be monopolar or bipolar and may be used to treat tissue using energy such as but not limited to cutting, coagulating, ablating and heating. An example electrosurgical instrument may include a Coblation wand, such as a wand described in U.S. Pat. No. 10,420,601, herein incorporated by reference in its entirety and commonly owned.
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.
Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
This application claims benefit to U.S. Provisional Application No. 62/962036 filed Jan. 16, 2020, titled “Articulating Shaft of a Surgical Device”, and incorporated by reference in its entirety. This application also claims benefit to U.S. Provisional Application No. 62/967,300, filed Jan. 28, 2020, titled “Articulating Shaft Liner of a Surgical Device”, incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/013811 | 1/18/2021 | WO |
Number | Date | Country | |
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62962036 | Jan 2020 | US | |
62967300 | Jan 2020 | US |