System and apparatus for wire guidance of a joint

Abstract

To provide an improved steering mechanism for a medical instrument including an endoscope.SOLUTION: A steering assembly for a medical device may include a handle having a recess and first and second wire guides disposed within the recess. At least one of the first or second wire guides may be secured in the recess to prevent rotation of the first or second wire guide within the recess. The first and second wire segments may be configured to advance a sheath coupled to the steering assembly in first and second directions. The first wire segment may pass through a first gap between the first wire guide and the second wire guide. The second wire segment may pass through a second gap between the first wire guide and the second wire guide. Neither the first gap nor the second gap may occupy an overlapping space.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to steering mechanisms for medical instruments, including endoscopes. In particular, the present disclosure relates to systems and methods for wire guidance in joints. [Background technology]

[0002] The handles of endoscopes house multiple components (e.g., steering components) that are separate from one another. Arranging such components within the handle has required the use of chains or similar components. Such components increase manufacturing costs by increasing part and assembly costs, making them unsuitable for use in manufacturing disposable devices. Therefore, there is a need for a simple, cost-effective steering assembly for an endoscope or other medical instrument. Summary of the Invention

[0003] In one example, a steering assembly of a medical device may include a handle having a recess and first and second wire guides disposed within the recess. At least one of the first or second wire guides may be secured to the recess to prevent rotation of the first or second wire guide within the recess. The first and second wire segments may be configured to advance a sheath coupled to the steering assembly in first and second directions. The first wire segment may pass through a first gap between the first and second wire guides. The second wire segment may pass through a second gap between the first and second wire guides. Neither the first gap nor the second gap may occupy an overlapping space.

[0004] Any example of a steering assembly described herein may have any of the following shapes. The steering assembly may further include a third wire guide and third and fourth wire segments configured to advance the sheath in third and fourth directions. The third wire segment may pass through a third gap between the second and third wire guides. The fourth wire may pass through a fourth gap between the second and third wire guides. The first and second gaps may be offset from one another. The first and second wire segments may be configured to control left-right movement of a sheath coupled to the steering assembly. The third and fourth wire segments may be configured to control up-down movement of a sheath coupled to the steering assembly. None of the first, second, third, or fourth gaps may occupy overlapping spaces. The first wire guide may include a first opening for accommodating a first axis component. The second wire guide may include a second opening for accommodating a second axis component. The third wire guide may include a third opening for accommodating a third axis component. The first, second, and third openings may each have a different diameter. The first and second wire guides may all be secured to the recesses to prevent rotation relative to the recesses when disposed therein. The first, second, and third wire guides may all be disposed within the recesses. The first, second, and third wire guides may all be secured to the recesses to prevent rotation relative to the recesses when disposed therein. The steering assembly may further include a first pulley coupled to the first and second wire segments. The first pulley may be disposed between the first and second wire guides. The second pulley may be coupled to the third and fourth wire segments. The second pulley may be disposed between the second and third wire guides. The thickness of the first pulley may maintain the first and second gaps. The thickness of the second pulley may maintain the third and fourth gaps. The first wire guide may have first and second offset surfaces that define first portions of the first and second gaps, respectively.The second wire guide may have third and fourth offset surfaces that define second portions of the first and second gaps, respectively. The first wire guide may have a first step surface extending from the first offset surface to the second offset surface. The second wire guide may have a second step surface extending from the third offset surface to the fourth offset surface. The first and second step surfaces may define third portions of the first and second gaps, respectively.

[0005] In a further example, a steering assembly of a medical device may include a handle and first, second, and third wire guides disposed within the handle. At least one of the first, second, or third wire guides may be constrained by an axis. The first and second wire segments may be configured to control movement of a sheath coupled to the handle in first and second directions, and the third and fourth wire segments may be configured to control movement of the sheath in third and fourth directions. The first wire segment may pass through a first gap between the first and second wire guides. The second wire segment may pass through a second gap between the first and second wire guides. The third wire segment may pass through a third gap between the second and third wire guides. The fourth wire segment may pass through a fourth gap between the second and third wire guides.

[0006] Any example of a steering assembly described herein may have any of the following shapes: None of the first, second, third, or fourth gaps may occupy overlapping spaces; The first and second gaps may be offset from one another. In another example, a steering assembly for a medical device may include first, second, and third wire guides disposed within a handle and a first pulley having first and second wires. The first pulley may be disposed between the first and second wire guides. The second pulley may have third and fourth wires. The second pulley may be disposed between the second and third wire guides. The first, second, and third wire guides and the first and second pulleys may be stacked together to completely contain the first, second, third, and fourth wire segments in separate compartments.

[0007] Any example of the steering assembly described herein may further include a handle. The handle may include a recess. The first, second, and third wire guides may all be secured to the recess to prevent rotation relative to the recess when positioned therein.

[0008] It will be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not limiting of the invention as claimed. As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to include a non-exclusive inclusion, such that a process, method, article, or device comprising a list of elements does not include only those elements, but may also include other elements not expressly listed or inherent in such process, method, article, or device. The term "exemplary" is used in the sense of "example," rather than "ideal." As used herein, the term "proximal" means closer to the operator, and the term "distal" means farther from the operator. Although endoscopes are referenced herein, references to endoscopes or endoscopy should not be construed as limiting the applicability of the disclosed handles and other embodiments. For example, the disclosed embodiments may be used with duodenoscopes, bronchoscopes, ureteroscopes, colonoscopes, catheters, diagnostic or therapeutic tools or devices, or other types of medical equipment.

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of the present disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. [Figure 1B] FIG. 1B is a perspective view of a handle component of the medical device of FIG. 1A. [Figure 2] 1B is a cross-sectional view of a portion of the medical device of FIG. 1A. [Figure 3] FIG. 1B is a perspective view of the medical device of FIG. 1A in a partially assembled state. [Figure 4A] FIG. 2 is a diagram showing a first wire guide. [Figure 4B] FIG. 2 is a diagram showing a first wire guide. [Figure 4C] FIG. 2 is a diagram showing a first wire guide. [Figure 4D] FIG. 2 is a diagram showing a first wire guide. [Figure 5A] 1B is a perspective view of a partially assembled handle component of the medical device of FIG. 1A. FIG. [Figure 5B] 1B is a perspective view of a partially assembled handle component of the medical device of FIG. 1A. FIG. [Figure 6A] FIG. 10 is a diagram showing a second wire guide. [Figure 6B] FIG. 10 is a diagram showing a second wire guide. [Figure 6C] FIG. 10 is a diagram showing a second wire guide. [Figure 6D] FIG. 10 is a diagram showing a second wire guide. [Figure 7A] 1B is a perspective view of a partially assembled handle component of the medical device of FIG. 1A. FIG. [Figure 7B] 1B is a perspective view of a partially assembled handle component of the medical device of FIG. 1A. FIG. [Figure 8A] FIG. 10 is a diagram showing a third wire guide. [Figure 8B] FIG. 10 is a diagram showing a third wire guide. [Figure 8C]FIG. 10 is a diagram showing a third wire guide. [Figure 9] 1B is a perspective view of a partially assembled handle component of the medical device of FIG. 1A. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The handle of an endoscope (e.g., the operating section of the endoscope) may include components used by an operator when performing a procedure with the endoscope. For example, the handle of an endoscope may include steering components or assemblies that may be used to deflect the distal end of the endoscope's sheath. These steering components or assemblies may include, for example, pulleys, drums, and / or wires. The wires of the steering assembly may pass distally from the handle (e.g., the handle) into the endoscope's sheath (e.g., the insertion section) and through the sheath toward the distal end of the sheath. The wires may be used to deflect the distal end of the sheath in one or more directions. For example, the sheath may include joints that allow movement in various directions (e.g., 90-360 degrees of movement). Alternatively, the sheath may include any other mechanism or structure that may be used to achieve movement of the distal end of the sheath. To effectively deflect the distal end of the sheath, it may be important to prevent the wires of the steering assembly from crossing each other. It may also be important to minimize friction between the drum and pulley or between the drum and pulley and optimize control of the drum and pulley or between the drum and pulley. It may also be desirable to utilize relatively inexpensive and easy to assemble components, or components that are relatively inexpensive or easy to assemble. Accordingly, aspects of the present disclosure relate to wire guides for positioning and housing wires, drums, and / or pulleys within an endoscope.

[0012] FIG. 1 illustrates a device 10. The device 10 may be an endoscope, duodenoscope, bronchoscope, ureteroscope, colonoscope, catheter, or other type of medical instrument. The device 10 may include a handle 12. The handle 12 may have any of the shapes described in U.S. Provisional Patent Application No. 06530-0876-00600, filed on the same day, entitled "Chambered Handle for a Medical Device," the entire disclosure of which is incorporated herein by reference. The device 10 may also include a sheath 14 or other type of tool that may be inserted into a body cavity of a subject during a medical procedure. The proximal end of the sheath 14 may be coupled to the handle 12. The sheath 14 may include a distal end 16. A distal tip 18 may be the most distal feature of the distal end 16. The distal tip 18 may include various components such as an elevator, air / water / suction openings, working channel openings, optics (e.g., a camera and / or lens), lighting devices (e.g., light emitting diodes), etc. Proximal to the distal tip 18 may be an articulation portion 20. The articulation portion 20 may include a mechanism configured to facilitate deflection of the distal end 16 in one or more directions (e.g., upward, downward, leftward, and / or rightward, perpendicular to the longitudinal axis of the device 10).

[0013] An umbilicus 24 may extend from the handle 12. The umbilicus 24 may be used to connect the device 10 to components such as a controller (e.g., for providing light control, including a camera, video, light source, or other light control), air and water supply or intake, and / or suction.

[0014] The handle 12 may include a number of components used by an operator to control the device 10 before, during, or after a procedure involving the device 10. For example, the handle 12 may include a steering component 30. The steering component 30 may be used to control the deflection of the articulation 20. The steering component 30 may be part of a steering assembly 100 (see FIG. 2 ), which is described in more detail below. For example, the steering component 30 may include two knobs 32, 34 used to deflect the distal end 16 of the sheath 14. For example, one of the knobs 32, 34 may be used to deflect the distal end 16 of the sheath 14 left and right, and the other of the knobs 32, 34 may be used to deflect the distal end 16 of the sheath 14 up and down. The steering component 30 may also include locking mechanisms 36, 38 that may be used to prevent or limit movement of the distal end 16 in the left and right and / or up and down directions when in a locked position. For example, locking mechanism 36 may be a knob that can be operated to prevent movement of knob 32, thereby preventing side-to-side deflection of distal end 16. Locking mechanism 38 may be a lever that can be operated to prevent movement of knob 34, thereby preventing vertical deflection of distal end 16. Any other suitable shape can be used to prevent movement of knobs 32, 34.

[0015] The handle 12 may also include multiple ports and / or valves. For example, the handle 12 may include a working channel port 40 that may be used to pass an instrument or other device through the working channel of the sheath 14. The working channel port 40 may be housed within a port housing 42. The port 40 may include a valve to prevent leakage. The handle 12 may also include fluidics components, such as valves 52 for providing air, water, and / or suction. The valves 52 may be connected to tubes in the umbilicus 24, the handle 12, and / or the sheath 14 such that pressing the valves 52, 54 enables the corresponding function. For example, one of the valves 52 may be used to provide air and / or water. Another of the valves 52 may be used to provide suction and may be connected to the working channel extending from the working channel port 40.

[0016] The handle 12 may also include other components, such as an elevator lever 60 that may be used to move an elevator (not shown) up or down at the distal tip 18 of the sheath 14. For example, an elevator lever 60 may be included when the device 10 is a duodenoscope.

[0017] The longitudinal axis of device 10 is the axis extending through handle 12 and sheath 14, and the longitudinal direction is the direction along the longitudinal axis. The radial direction is the direction perpendicular to the longitudinal axis.

[0018] FIG. 1B shows the body 70 of the handle 12 without many of the components used to operate the device 10 attached. The body 70 may include a first recess 80. The first recess 80 may have a wall 82 surrounding part, but not all, of the first recess 80. The first recess 80 may be open at its distal end and on the exterior of the body 70. The first recess 80 may have a rounded proximal-most side or end 84, which may be semicircular or U-shaped. An inner surface 83 (which may be the bottom surface) of the first recess 80 may extend from the open distal end to the rounded proximal-most end 84, opposite the open exterior. The inner surface 83 may be parallel or substantially parallel to the longitudinal axis of the body 70 and / or device 10. The first recess 80 may have two side surfaces 86 extending between the open distal end and the rounded proximal-most side 84. As used herein, the outward direction is the direction extending from the inner surface 83 through the open exterior of the first recesses 80, and the inward direction is the opposite direction. Alternatively, the first recesses 80 may have walls 82 surrounding other subsets of the first recesses 80. The first recesses 80 may include second recesses 88 that may be recessed deeper than the first recesses 80 relative to the open exterior of the first recesses 80. For example, the second recesses 88 may be recessed from the inner surface 83.

[0019] The wall 82 may have a uniform height or a varying height as measured radially along the body 70. The ridge 90 may extend around a portion of the circumference of the first recess 80. For example, the ridge 90 of the first recess 80 may extend around the curved proximal-most side 84. The ridge 90 may also extend along a portion of the side surface 86 of the first recess 80. For example, the ridge 90 may extend along a portion of the straight side of the first recess 80 that is closer to the umbilicus 24.

[0020] As shown in FIG. 2 , the cable steering assembly 100 may be mounted within, disposed on, or otherwise attached to the handle 12. For example, the cable steering assembly 100 may be housed within the first recess 80. The cable steering assembly 100 may include a shaft assembly 120, which may include one or more shafts, as described in further detail below. The cable steering assembly may also include two wire pairs 122, 124 for providing flexure at the distal end 16 of the sheath 14. Each wire pair 122, 124 may include two separate wires, each of which may terminate in a ferrule and be secured in a slot in a pulley (as described in further detail below). Alternatively, each wire pair 122, 124 may include a pair of wire segments formed by a single wire wound around a spool or pulley. The first wire pair 122 may control movement in one direction, such as left and right. The second wire pair 124 may control movement in another direction, such as up and down. The configuration of wire pairs 122, 124 is exemplary only, as alternative structures may be used, and wire pairs 122, 124 may be omitted if other types of mechanisms are used to deflect distal end 16 of sheath 14.

[0021] The first wire pair 122 may include a first wire (or wire segment) 132 and a second wire (or wire segment) 134. Proximal movement of the first wire 132 may deflect the distal end 16 of the sheath 14 in a first direction (e.g., to the right). Proximal movement of the second wire 134 may deflect the distal end 16 of the sheath 14 in a second direction (e.g., to the left), opposite the first direction. Proximal movement of the first wire 132 may be accompanied by distal movement of the second wire 134. Proximal movement of the second wire 134 may be accompanied by distal movement of the first wire 132. The first wire 132 and the second wire 134 may be moved proximally or distally, for example, by rotating the knob 32 or by actuating an alternative mechanism, such as another component of the steering component 30. Rotating the knob 32 in a first direction may cause deflection in a first direction, and rotating the knob 32 in a second direction may cause deflection in a second direction.

[0022] The second wire pair 124 may include a third wire 136 and a fourth wire 138. Proximal movement of the third wire 136 may deflect the distal end 16 of the sheath 14 in a third direction (e.g., downward). Proximal movement of the fourth wire 138 may deflect the distal end 16 of the sheath 14 in a fourth direction (e.g., upward), opposite the third direction. Proximal movement of the third wire 136 may be accompanied by distal movement of the fourth wire 138. Proximal movement of the fourth wire 138 may be accompanied by distal movement of the third wire 136. The third wire 136 and the fourth wire 138 may be moved proximally or distally, for example, by rotating the knob 34 or by actuating an alternative mechanism, such as another component of the steering component 30. Rotating the knob 34 in a first direction may cause deflection in a third direction, and rotating the knob 34 in a second direction may cause deflection in a fourth direction.

[0023] As shown in FIG. 2 , the first wire 132 and the second wire 134 may be spaced apart and maintained substantially parallel to one another in the first recess 80 of the handle 12 by the first wire guide 142 and / or the second wire guide 144. As described in more detail below, the interaction between the first wire guide 142 and the second wire guide 144 may facilitate spacing the first wire 132 and the second wire 134 relative to one another. The third wire 136 and the fourth wire 138 may be spaced apart and maintained substantially parallel to one another in the first recess 80 of the handle 12 by the second wire guide 144 and / or the third wire guide 146. As described in more detail below, the interaction between the second wire guide 144 and the third wire guide 146 may facilitate spacing the third wire 136 and the fourth wire 138 relative to one another. 2, the second wire guide 144 may help space the second wire pair 124 from the first wire pair 122. The second wire guide 144 may keep the first wire 132 substantially parallel to the third wire 136 in the first recess 80. The second wire guide 144 may also keep the second wire 134 substantially parallel to the fourth wire 138 in the first recess 80.

[0024] Wire guides 142, 144, and 146 may keep wires 132, 134, 136, and 138 apart. For example, wire guides 142, 144, and 146 may be positioned to space wires 132, 134, 136, and 138 from one another and maintain their position on their respective pulleys. In other words, wire guides 142, 144, and 146 may form a barrier to prevent wires 132, 134, 136, and 138 from contacting one another. This may help prevent wires 132, 134, 136, and 138 from crossing, which could impede advancement of distal end 16 of sheath 14. Furthermore, this may help ensure that the wires remain in the proper position relative to the pulleys.

[0025] 3 shows the first recess 80 and ridge 90 separated from the other components of the handle 12. A shaft 172 of the steering component 30 may be secured to the body of the handle 12. For example, the shaft 172 may be secured to the body of the handle 12 using a washer or a flange 174. The flange 174 may have a shape complementary to the second recess 88 such that a keyed relationship exists between the flange 174 and the second recess 88. The keyed relationship between the flange 174 and the second recess 88 may minimize or completely prevent rotation of the flange 174 within the second recess 88.

[0026] 4A-4D show embodiments of the first wire guide 142. FIG. 4A shows a front view of the first wire guide 142. FIGS. 4B and 4C show perspective views of the first wire guide 142. FIG. 4D shows a bottom view of the first wire guide 142. FIGS. 5A and 5B show the first wire guide 142 positioned within the first recess 80. The first wire guide 142 may have an outer periphery that complements the shape of the first recess 80. For example, as shown in FIG. 4A, the proximal-most portion or side 180 of the first wire guide 142 may have a rounded shape. The radius of curvature of the proximal-most side 180 of the first wire guide 142 may be the same as or slightly smaller than the radius of curvature of the proximal-most side 84 of the first recess 80. The first wire guide 142 may have a fixed relationship with the first recess 80 to minimize or prevent rotation of the first wire guide 142 relative to the first recess 80. As also shown in FIG. 4A , the first wire guide may include a distal-most side 182, which may be straight. The first wire guide 142 may also include a first side 184 and a second side 186, both of which may extend between the proximal-most side 180 and the distal-most side 182. The first and second sides 184, 186 may be shaped to mate with the wall 86 of the first recess 80. For example, the first and second sides 184, 186 may be straight. The shape of the first wire guide 142 may aid in quick installation of the first wire guide 142 because the wire guide 142 is not symmetrical and must be placed so that the curved most proximal side 180 of the first wire guide 142 is adjacent to the most proximal side 84 of the first recess 80.

[0027] The first wire guide 142 may have an opening 190. The opening 190 may have a rounded shape (e.g., circular). The opening 190 may be sized to have a diameter approximately the same as or slightly larger than the diameter of the shaft 172. The opening 190 may be located closer to the proximal-most side 184 than to the distal-most side 182. The opening in any of the wire guides disclosed herein may be constrained by interaction between the opening in the wire guide and the shaft 172 (or other axis or shaft).

[0028] The first wire guide 142 may have a first side 192 and a second side 194, both of which may extend from a proximal-most side 180 to a distal-most side 182. Figure 4B particularly illustrates an embodiment of the first side 192. Figure 4C particularly illustrates an embodiment of the second side 194.

[0029] The first wire guide 142 may have a proximal portion 196. The proximal portion 196 may have a washer-type shape. For example, the proximal portion 196 may include the opening 190 and may include a portion of the first wire guide 142 that is concentric with the opening 190.

[0030] The first wire guide 142 may also have a first distal portion 202 and a second distal portion 204. The first distal portion 202 may extend from the first side 184 toward the second side 186, but may terminate before the second side 186. The second distal portion 204 may extend from the second side 186 toward the first side 184, but may terminate before the first side 184. For example, the first distal portion 202 and the second distal portion 204 may each terminate midway or approximately midway between the first side 184 and the second side 186, although other dimensions are contemplated. The first distal portion 202 and the second distal portion 204 may each have a thickness that exceeds the thickness of the proximal portion 196. In other words, the distance between the first side 192 and the second side 194 may be greater at each of the first distal portion 202 and the second distal portion 204 than at the proximal portion 196. As shown in FIG. 4B, the first distal portion 202 and the second distal portion 204 may be raised or protruding relative to the proximal portion 196 of the first side 192.

[0031] 4B , the first distal portion 202 may be more raised relative to the proximal portion 196 than the second distal portion 204. The first distal portion 202 may be thicker than the second distal portion 204. In other words, the distance between the first side 192 and the second side 194 may be greater at the first distal portion 202 than at the second distal portion 204.

[0032] FIG. 4D shows a bottom view of the first wire guide 142 to illustrate the distal-most side 182. Along the distal-most side 182, the second side 194 may be flat. Along the distal-most side 182, the first side 192 may be staggered such that there is a first flat portion 206 (along the first distal portion 202) and a second flat portion 208 (along the second distal portion 204), and there may be a step 210 between the first flat portion 206 and the second flat portion 208. The first flat portion 206 and the second flat portion 208 may be offset from each other. The first flat portion 206 and the second flat portion 208 may be substantially parallel to each other. The step 210 may form a boundary between the first flat portion 206 and the second flat portion 208. The step 210 may be substantially perpendicular to both the first flat portion 206 and the second flat portion 208.

[0033] On the first side 192, the first distal portion 202 may have a proximal edge 212, and the second distal portion 204 may have a proximal edge 214. The proximal edges 212, 214 of the first and second distal portions 202, 204 may each be adjacent to the proximal portion 196. The proximal edges 212, 214 may each be a segment of the same circle or may have a rounded, concave shape. The proximal edges 212, 214 may have the same or similar shape when viewed from the front of the first side 192, as shown in FIG. 4A , but the proximal edges 212, 214 may have different thicknesses. For example, the proximal edge 212 may be thicker than the proximal edge 214. The difference in thickness between the proximal edge 212 and the proximal edge 214 may correspond to the difference in thickness between the first distal portion 202 and the second distal portion 204.

[0034] 4C , the first distal portion 202 may be hollow such that the first distal portion 202 includes a recess 230 on the second side 194. The recess 230 may have an inner wall 232 that follows the contours of the first distal portion 202. The fact that the first distal portion 202 may be hollow may result in reduced manufacturing costs and weight of the first wire guide 142. The recess 230 may maintain a consistent thickness of the wall of the first wire guide 142 to facilitate molding or other manufacturing techniques for the first wire guide 142. Alternatively, the recess 230 may have any of the characteristics of the recess 430 described below with respect to the third wire guide 146. The recess 230 or another portion of the first wire guide 142 may also include an indicator 234. The indicator 234 may indicate, for example, the orientation of the wire guide 142 within the handle 12. For example, indicator 234 may be, for example, a first symbol "B" or any other suitable symbol to indicate that first wire guide 142 is the bottom wire guide adjacent inner surface 83 of recess 80. Alternatively, other indicators may be used.

[0035] FIG. 5A shows the first wire guide 142 installed within the recess 80. FIG. 5B shows the first pulley 250 mounted adjacent to (above) the first side 192 of the first wire guide 142. As used herein, the terms "above" or "upper" refer to an outward direction toward the open exterior of the recess 80. The terms "below" or "lower" refer to an inward direction toward the inner surface 83. The first wire guide 142 may be positioned within the first recess 80 such that the second side 194 of the first wire guide 142 is adjacent to the inner surface 83 of the first recess 80. The first side 192 may face the open exterior of the first recess 80. The shaft 172 may extend through the opening 190. For example, the first wire guide 142 may be positioned such that the axis 172 is aligned with the opening 190, and then the first wire guide 142 may be advanced along the axis 172 until it rests on the inner surface 83 of the first recess 80. The first pulley 250 may be adjacent to the first wire guide 142, or there may be a gap between the first pulley 250 and the first wire guide 142. The first pulley 250 may have a spool shape. The first pulley 250 may have an outer diameter such that the first pulley 250 is aligned with the proximal portion 196 of the first wire guide 144 and adjacent the proximal edges 212, 214. For example, the diameter of the proximal portion 196 may be substantially equal to the diameter of the first pulley 250. The first wire pair 122 (the first wire 132 and the second wire 134) may be wound around the first pulley 250. As described above, the first wire pair 122 may be a single continuous wire or may include separate wires. The first pulley 250 may be attached to a first pulley shaft 252, which may be a component of the shaft assembly 120 and may be coaxial with the shaft 172. The first pulley shaft 252 may be fixed relative to the first pulley 250 such that rotation of the first pulley shaft 252 causes rotation of the first pulley 250. The first pulley shaft 252 may be operably connected to the knob 32 to cause rotation of the first pulley shaft 252. The first wire 132 may pass along the first flat surface 206 of the first distal portion 202. The second wire 134 may pass along the second flat surface 206 of the second distal portion 204.

[0036] 6A-6D show an embodiment of second wire guide 144. FIGS. 7A-7B show second wire guide 144 installed in first recess 80 of handle 12. The outer circumferential shape of second wire guide 144 may have any of the outer circumferential shapes of first wire guide 142 described above. For example, second wire guide 144 may have the same outer circumferential shape as first wire guide 142. For example, as described above with respect to first wire guide 142, second wire guide 144 may have an outer circumferential shape that complements the shape of first recess 80.

[0037] The second wire guide 144 may include a proximal-most side 280, which may be curved, and a distal-most side 282, which may be straight. The second wire guide 144 may also include a first side 284 and a second side 286, both of which may extend between the proximal-most side 280 and the distal-most side 282. The first and second sides 284, 286 may be shaped to mate with the side surface 86 of the first recess 80. For example, the first and second sides 284, 286 may be straight. The shape of the first wire guide 144 may aid in rapid installation of the second wire guide 144.

[0038] The second wire guide 144 may have an opening 290. The opening 290 may have a rounded shape (e.g., a circular shape). The opening 290 may be sized to have approximately the same diameter as the first pulley shaft 252. The opening 290 may have a diameter slightly larger than the diameter of the first pulley shaft 252. The opening 290 may be located closer to the proximal-most side 280 than to the distal-most side 282. Because the first pulley shaft 252 may have a larger diameter than the shaft 172, the opening 290 may have a larger diameter than the opening 190.

[0039] The second wire guide 144 may have a first side 292 (see FIGS. 6A and 6B) and a second side 294 (see FIG. 6C), both of which may extend from the proximal-most end 280 to the distal-most end 282. The first side 292 and the second side 294 may be the same as one another when viewed from the front. Thus, while FIG. 6A specifically shows the first side 292, the first side 292 may be the same as the second side 294.

[0040] The second wire guide 144 may have a proximal portion 296. The proximal portion 296 may have a washer-type shape. For example, the proximal portion 296 may include the opening 290 and may include a portion of the second wire guide 144 that is concentric with the opening 290.

[0041] The second wire guide 144 may also have a first distal portion 302 and a second distal portion 304. The first distal portion 302 may extend from the first side 284 toward the second side 286, but may terminate before the second side 286. The second distal portion 304 may extend from the second side 286 toward the first side 284, but may terminate before the first side 284. For example, the first distal portion 302 and the second distal portion 304 may each terminate halfway or approximately halfway between the first side 284 and the second side 286. The first distal portion 302 and the second distal portion 304 may each have a thickness that exceeds the thickness of the proximal portion 296. In other words, the distance between the first side 292 and the second side 294 may be greater at each of the first distal portion 302 and the second distal portion 304 than at the proximal portion 296. As shown in FIG. 4B, the first distal portion 302 and the second distal portion 304 may be raised or protruding relative to the proximal portion 296 of the first side 292 and the second side 294.

[0042] 6A and 6B, on the first side 292, the first distal portion 302 may be raised or protrude further relative to a plane defining the proximal portion 296 than the second distal portion 304. On the second side 294, the second distal portion 304 may be raised or protrude further relative to a plane defining the proximal portion 296 than the first distal portion 302.

[0043] 6D shows a proximal bottom view of the second wire guide 144 to show the distal-most side 282. The thickness of the first distal portion 302 at the distal-most side 282 may be the same as the thickness of the second distal portion 304 at the distal-most side 282. Alternatively, the first distal portion 302 may have a different thickness at the distal-most side 282 than the second distal portion 304. Along both the first side 292 and the second side 294, the distal-most sides 282 may be staggered. The first side 292 may have a first flat portion 306 (along the first distal portion 302) and a second flat portion 308 (along the second distal portion 304), with a first step 336 between the first flat portion 306 and the second flat portion 308 (as described below, the first distal portion 302 may be hollow at the surface of the first side 292, but may be flat along the most distal side 282 and the second side 294). The first flat portion 306 may be substantially parallel to and offset from the second flat portion 308, and the step 336 may be substantially perpendicular to both the first flat portion 306 and the second flat portion 308. On the second side 294, there are a third flat portion 310 and a fourth flat portion 312 (as described below, the second distal portion 304 may be hollow at the surface of the second side 294, but may be flat along the distal-most side 282 and the first side 292), and there may be a second step 338 between the third flat portion 310 and the fourth flat portion 312. The third flat portion 310 may be substantially parallel to and offset from the fourth flat portion 312, and the step 338 may be substantially perpendicular to both the third flat portion 310 and the fourth flat portion 312. The first step 336 and the second step 338 may be approximately midway between the first side 284 and the second side 286, although other dimensions are contemplated. The first step 336 and the second step 338 may be aligned with each other or offset from each other.

[0044] On the first side 292, the first distal portion 302 can have a first proximal edge 316, and the second distal portion 304 can have a first proximal edge 320. On the second side 294, the first distal portion 302 can have a second proximal edge 318, and the second distal portion 304 can have a second proximal edge 322. The proximal edges 316, 318, 320, and 322 can be adjacent to the proximal portion 296. The proximal edges 316, 318, 320, and 322 can have a rounded, concave shape, which can each be a segment of the same circle. The proximal edges 316, 318, 320, and 322 may have the same or similar shapes when the first side 192 or the second side 194 is viewed from the front (however, the proximal edges 316, 318, 320, and 322 may have different thicknesses). The first proximal edge 316 of the first distal portion 302 may have a greater thickness than the second proximal edge 318 of the first distal portion 302. The second proximal edge 322 of the second distal portion 304 may have a greater thickness than the first proximal edge 320 of the second distal portion 304. The first proximal edge 316 of the first distal portion 302 may have a greater thickness than the first proximal edge 320 of the second distal portion 304. The second distal portion 304 may be raised or protrude more than the first distal portion 302 of the second side 294, and the second side proximal edge 322 of the second distal portion 304 may have a greater thickness than the second side proximal edge 318 of the first distal portion 302.

[0045] The first and second distal portions 302, 304 may be hollow. For example, the first distal portion 302 may include a recess 340 on the first side 292. The recess 340 may have an inner wall 342 that follows the contour of the first distal portion 302. The second distal portion 304 may include a recess 350 on the second side 294. Referring to FIG. 6C , the recess 350 may have an inner wall 352 that follows the contour of the second distal portion 304. The fact that the first distal portions 302, 304 may be hollow may result in reduced manufacturing costs and weight of the second wire guide 242.

[0046] One or both of the recesses 340, 350 may include an indicator 360. The indicator 360 may indicate, for example, the orientation of the second wire guide 144 within the handle 12. For example, the indicator 350 may be an "M" or a second symbol different from the indicator 234 to indicate that the second wire guide 144 is an intermediate wire guide above the first wire guide 142. Alternatively, other indicators may be used.

[0047] FIG. 7A shows the second wire guide 144 installed within the recess 80. FIG. 7B shows the second pulley 360 mounted adjacent to (above) the first pulley 250. The second wire guide 144 may be positioned within the first recess 80 such that the second side 294 of the second wire guide 144 faces the inner surface 83 of the first recess 80. The first side 292 may face the exterior-opening side of the first recess 80. It should be noted that the first side 292 and the second side 294 may be identical, and therefore the second wire guide 144 may be positioned such that the second side 294 faces the inner surface 83. As shown in FIGS. 7A and 7B, the first pulley shaft 252 may extend through the opening 290. For example, the second wire guide 144 may be positioned so that the first pulley axis 252 is aligned with the opening 290, and then the second wire guide 144 may be advanced along the first pulley axis 252 until the second side 294 is adjacent to the first pulley 250.

[0048] The proximal portion 296 of the second wire guide 144 may be disposed adjacent to the surface of the first pulley 250, facing the open exterior of the recess 80. A second side 294 of the proximal portion 296 of the second wire guide 144 may rest on the outward-facing surface of the first pulley 250, with the second side 294 facing the open exterior of the recess 80. The first pulley 250 may have an outer diameter such that the first pulley 250 may be aligned with the proximal portion 296 of the second wire guide 144. For example, the first pulley 250 may have a diameter substantially equal to the diameter of the proximal portion 296. A gap may be formed between the first side 192 of the first wire guide 142 and the second side 294 of the second wire guide 144 due to the thickness of the first pulley 250 and the difference in relative height between the wire guides 142, 144 and the pulley 250. More specifically, the first gap 366 may be formed between the first side 192 of the first distal portion 202 of the first wire guide 142 and the second side 294 of the first distal portion 302 of the second wire guide 144. The second gap 368 may be formed between the first side 192 of the second distal portion 204 of the first wire guide 142 and the second side 294 of the second distal portion 304 of the second wire guide 144. The first gap 366 and the second gap 368 may not occupy an overlapping space. The first gap 366 may be offset from the second gap 368. The first wire 132 may pass through the gap 366, and the second wire 134 may pass through the gap 368. Walls 210 and / or 338 may prevent first wire 132 and / or second wire 134 from moving laterally past walls 210 and / or 338. For example, walls 210 and / or 338 may restrict wires 132 and / or 134 from moving past the centerline of first recess 80. Gap 366 may be a hole or compartment formed by first side 192 of first distal portion 202 of first wire guide 142, second side 294 of first distal portion 302 of second wire guide 144, step 338, and side surface 86 of first recess 80. The gap 368 may be a hole or partition formed by the first side 192 of the second distal portion 204 of the first wire guide 142, the second side 294 of the second distal portion 304 of the second wire guide 144, the step 210, and the side 86 of the first recess 80.Gaps 366 and / or 368 may have a substantially rectangular cross-section. Gaps 366 and / or 368 may be closed on all four sides or may not be completely closed. For example, gap 366 may be open to gap 368 through the space between walls 210 and 338.

[0049] As shown in FIG. 7B , the second pulley 360 may be disposed adjacent to (e.g., above) the second wire guide 144. The second pulley 360 may have a spool shape. The outer diameter of the second pulley 360 may be such that the second pulley 360 is aligned with the outer diameter of the proximal portion 296 of the second wire guide 144. For example, the second pulley 360 may have an outer diameter substantially equal to the outer diameter of the first pulley 250 and the proximal portions 186, 296 or the first pulley 250 or the proximal portions 186, 296. The second wire pair 124 (the third wire 136 and the fourth wire 138) may be coupled to the second pulley 360. As described above, the second wire pair 124 may be a single continuous wire or may include separate wires. The second pulley 360 may be attached to a second pulley shaft 370, which may be coaxial with the shaft 172 and / or the first pulley shaft 252 and may be a component of the shaft assembly 120. The second pulley shaft 370 may be fixed relative to the second pulley 360 such that rotation of the second pulley shaft 370 causes rotation of the second pulley 360. The second pulley shaft 370 may have a larger outer diameter than the first pulley shaft 252, and the second pulley shaft 370 may fit over the first pulley shaft 252 as part of the shaft assembly 120. The second pulley shaft 370 may be operably connected to the knob 34 to cause rotation of the second pulley shaft 370. The third wire 136 may pass along the first distal portion 302. The fourth wire 138 may pass along the second distal portion 204.

[0050] 8A-8C show embodiments of a third wire guide 146. FIG. 9 shows a third wire guide installed within a cable steering assembly 100. The third wire guide 146 may have the shape of either the first wire guide 142 or the second wire guide 144. For example, the third wire guide 146 may have a shape complementary to the first recess 80. For example, the proximal-most portion or side 380 of the third wire guide 146 may have a rounded shape. The radius of curvature of the proximal-most side 380 of the third wire guide 146 may be the same as or similar to the radius of curvature of the proximal-most side 84 of the first recess 80. The third wire guide 146 may have a fixed relationship with the first recess 80 to minimize or prevent rotation of the third wire guide 146 relative to the first recess 80 or ridge 90. The third wire guide 146 may include a distal-most side 382, ​​which may be straight. The third wire guide 146 may also include a first side 384 and a second side 386 , both of which may extend between the proximal-most side 380 and the distal-most side 382 .

[0051] The third wire guide 146 may have an opening 390. The opening 390 may have a rounded shape (e.g., a circular shape). The opening 390 may be sized to have approximately the same diameter as the second pulley shaft 370. The opening 390 may have a diameter slightly larger than the diameter of the second pulley shaft 370. The opening 390 may be located closer to the proximal-most end 380 of the third wire guide 146 than to the distal-most end 382 of the third wire guide 146. The opening 390 may be larger than each of the openings 190 and 290.

[0052] The third wire guide 146 may have a first side 392 (see FIG. 8B) and a second side 394 (see FIG. 8A), both of which may extend from a proximal-most side 380 to a distal-most side 382. The first side 392 of the third wire guide 146 may be the same as the first side 192 of the first wire guide 142, except that the opening 390 is larger than the opening 190, resulting in a larger size of the second pulley shaft 370 than the shaft 172.

[0053] The third wire guide 146 may have a proximal portion 396. The proximal portion 396 may have a washer-type shape. For example, the proximal portion 396 may include an opening 390 and may include a portion of the third wire guide 146 that is concentric with the opening 390. For example, the proximal portion 396 may have an inner diameter that is approximately the same as the diameter of the second pulley shaft 370 and an outer diameter that is approximately the same as the outer diameter of the second pulley 360. The second pulley 360 may be aligned with the proximal portion 396.

[0054] The third wire guide 146 may also have a first distal portion 402 and a second distal portion 404. The first distal portion 402 may extend from the second side 386 toward the first side 384, but may terminate before the first side 384. The second distal portion 404 may extend from the first side 384 toward the second side 386, but may terminate before the second side 386. For example, the first distal portion 402 and the second distal portion 404 may each terminate midway or approximately midway between the first side 384 and the second side 386, although other dimensions are contemplated. The first distal portion 402 and the second distal portion 404 may each have a thickness that exceeds the thickness of the proximal portion 396. In other words, the distance between the first side 392 and the second side 394 may be greater at each of the first distal portion 402 and the second distal portion 404 than at the proximal portion 396. The first distal portion 402 and the second distal portion 404 may be raised or protruding relative to the proximal portion 396 of the first side 392.

[0055] At the first side 392, the first distal portion 402 may protrude or rise more than the second proximal portion 404 relative to the proximal portion 396. The first distal portion 402 may be thicker than the second distal portion 404. In other words, the distance between the first side 392 and the second side 394 may be greater at the first distal portion 402 than at the second distal portion 404.

[0056] 8C shows a bottom view of the third wire guide 146 to illustrate the distal-most side 382. The distal-most side 382 may have a larger cross-section at the first distal portion 402 than at the second distal portion 404. In other words, the distance between the first side 392 and the second side 394 along the distal-most side 382 may be larger at the first distal portion 402 than at the second distal portion 404. Along the distal-most side 382, ​​the first side 392 may be staggered such that there is a first flat portion 406 (along the first distal portion 402) and a second flat portion 408 (along the second distal portion 404) with a step 410 between the first flat portion 406 and the second flat portion 408. The first flat portion 406 and the second flat portion 408 may be substantially parallel and offset from one another. The step 410 may form a boundary between the first flat portion 406 and the second flat portion 408. The step 410 may be substantially perpendicular to both the first flat portion 406 and the second flat portion 408.

[0057] On the first side 392, the first distal portion 402 may have a proximal edge 412, and the second distal portion 404 may have a proximal edge 414. The proximal edges 412, 414 of the first and second distal portions 402, 404 may each be adjacent to the proximal portion 396. The proximal edges 412, 414 may each be a segment of the same circle, or may have a rounded, concave shape. The proximal edges 412, 414 may have the same or similar shape when the first side 192 is viewed from the front, but the proximal edges 412, 414 may have different thicknesses. For example, the proximal edge 414 may be thicker than the proximal edge 412 due to the fact that the first distal portion 202 protrudes more than the distal portion 204 relative to the proximal portion 396.

[0058] 8A , the first distal portion 402 may be hollow such that the first distal portion 402 includes a recess 430 on the second side 194. The recess 230 may have an inner wall 432 that follows the contour of the first distal portion 402. Alternatively, the recess 430 may only include an inner wall 432 that corresponds to the proximal edge 412 and the wall 410 such that the recess 430 is open at the distal-most side 382 of the third wire guide 146 and the second side 386 of the third wire guide 146. The fact that the first distal portion 402 may be hollow may result in reduced manufacturing costs and weight of the third wire guide 146. The shape of the recess 430 may also facilitate placement of other features in the handle 12 (e.g., an elevator articulation mechanism or other feature). The recess 430 or another portion of the third wire guide 146 may also include an indicator 434. Indicator 434 may indicate, for example, the orientation of third wire guide 146 within handle 12. For example, indicator 434 may be a "T" or third symbol different from indicators 234, 360 to indicate that third wire guide 146 is the top wire guide facing outward from recess 80. Alternatively, other indicators may be used.

[0059] FIG. 9 shows a third wire guide 146 installed in the cable steering assembly 100. The third wire guide 146 may be positioned within, around, or on the first recess 80 so that a first side 392 of the third wire guide 146 is adjacent to the surface of the second pulley 360 that faces the open outer surface of the first recess 80. A second side 394 may face the open outer surface of the first recess 80. A second pulley shaft 370 may extend through the opening 390. For example, the third wire guide 146 may be positioned so that the axis of the second pulley 370 is aligned with the opening 390, and then the third wire guide 146 may be advanced along the third pulley shaft 370 until the third wire guide 146 rests on the surface of the second pulley 360 that is closest to the open outer surface of the first recess 80. A proximal portion 396 of the third wire guide 146 may be positioned to rest adjacent to and on the outward-facing surface of the second pulley 360. As described above, the second pulley 360 may have an outer diameter such that the second pulley 360 is aligned with the proximal portion 396 of the third wire guide 146. For example, the second pulley 360 may have substantially the same outer diameter as the proximal portion 396.

[0060] A gap may be formed between the first side 292 of the second wire guide 144 and the first side 392 of the third wire guide 146. More specifically, a third gap 466, which is the thickness of the second pulley 360, may be formed between the first side 292 of the first distal portion 302 of the second wire guide 144 and the first side 392 of the second distal portion 404 of the third wire guide 146. A fourth gap 468, which is the thickness of the second pulley 360, may be formed between the first side 292 of the second distal portion 304 of the second wire guide 144 and the first side 392 of the first distal portion 402 of the third wire guide 146. The third gap 466 and the fourth gap 468 may be offset from each other and from the first gap 366 and the second gap 368, respectively. The third gap 466 and the fourth gap 468 may be separated by one or more walls 336 and 410. The first, second, third, and fourth gaps 366, 368, 466, 468 may not occupy overlapping spaces. The third wire 136 may pass through the third gap 466, and the fourth wire 138 may pass through the fourth gap 468. One or both of the walls 410 and 336 may restrict lateral movement of the third wire 136 and / or the fourth wire 138. For example, one or both of the walls 410 and 336 may restrict the wires 136 and / or the fourth wire 138 from crossing the centerline of the first recess 80. The third gap 466 may be a hole or compartment formed by the first side 292 of the first distal portion 302 of the second wire guide 144, the first side 392 of the second distal portion 404 of the third wire guide 146, the wall 410, and the side surface 86 of the first recess 80. The fourth gap 468 may be a hole or compartment formed by the first side 392 of the second distal portion 304 of the second wire guide 144, the first side 392 of the first distal portion 402 of the third wire guide 146, the wall 336, and the side surface 86 of the first recess 80. The gaps 466 and / or 468 may have a substantially rectangular cross-section. The gaps 466 and / or 468 may be closed on all four sides or may not be completely closed. For example, the gap 466 may be open to the gap 468 by the space between the walls 410 and 336.

[0061] The second side 394 of the third wire guide 146 may be the component of the cable steering assembly 100 closest to the open side of the first recess 80, and the second side of the third wire guide 146 may form a plane away from the recess 430.

[0062] The opening 290 of the second wire guide 144 may be larger than the opening 190 of the first wire guide 142 to accommodate the larger diameter first pulley shaft 252 as opposed to shaft 172. The opening 390 may be larger than the openings 290 and 190 to accommodate the larger diameter second pulley shaft 370 as compared to the first pulley shaft 252 and shaft 172. The thickness of the distal-most side 282 of the second wire guide 244 may be larger than the thickness of either the distal-most side 182 of the first wire guide 142 or the distal-most side 382 of the third wire guide 146. The first wire guide 142, the second wire guide 144, and the third wire guide 146 may have the same outer circumferential dimensions. In particular, the proximal portions 196, 296, and 396 of the first, second, and third wire guides 142, 144, and 146, respectively, may have the same outer diameter. The first and third wire guides may be identical or may be identical except for the size of openings 190, 290, indicators 434 and 234, and / or the shape of recesses 230, 430. For example, opening 290 may be larger than opening 190, and recess 430 may have an open side while recess 230 is completely closed.

[0063] While the principles of the present disclosure have been described herein with reference to illustrative embodiments for particular applications, it should be understood that the disclosure is not limited thereto. Those skilled in the art with access to the teachings provided herein will recognize that all additional modifications, uses, and substitutions of equivalents are within the scope of the embodiments described herein. Accordingly, the present invention should not be deemed limited by the foregoing description.

Claims

1. 1. A steering assembly for a medical device, comprising: a handle having a recess; first and second wire guides disposed within the recess, at least one of the first or second wire guides being fixed in the recess to prevent rotation of the first or second wire guide within the recess; first and second wire segments configured to advance a sheath coupled to the steering assembly in first and second directions, a steering assembly, wherein the first wire segment passes through a first gap between the first wire guide and the second wire guide, and the second wire segment passes through a second gap between the first wire guide and the second wire guide, and wherein neither the first gap nor the second gap occupies an overlapping space.

2. The steering assembly includes: a third wire guide; third and fourth wire segments configured to advance the sheath in third and fourth directions; 2. The steering assembly of claim 1, wherein the third wire segment passes through a third gap between the second wire guide and the third wire guide, and the fourth wire segment passes through a fourth gap between the second wire guide and the third wire guide.

3. 3. A steering assembly according to claim 1 or 2, wherein the first gap and the second gap are offset from each other.

4. The steering assembly of any one of claims 1 to 3, wherein the first and second wire segments are configured to control left and right movement of the sheath coupled to the steering assembly.

5. The steering assembly of claim 2 , wherein the third and fourth wire segments are configured to control the up and down movement of the sheath coupled to the steering assembly.

6. 6. A steering assembly as claimed in claim 2 or 5, wherein none of the first, second, third or fourth gaps occupy an overlapping space.

7. 7. A steering assembly as claimed in any one of claims 2, 5 or 6, wherein the first wire guide has a first opening for accommodating a first axis component, the second wire guide has a first opening for accommodating a second axis component, and the third wire guide has a third opening for accommodating a third axis component, each of the first, second and third openings having a different diameter.

8. A steering assembly according to any one of claims 1 to 7, wherein each of the first and second wire guides is fixed in the recess to prevent rotation relative to the recess when disposed in the recess.

9. 8. A steering assembly according to claim 2, wherein the first, second and third wire guides are all disposed within the recesses.

10. A steering assembly according to any one of claims 2, 5 to 7, and 9, wherein each of the first, second, and third wire guides is fixed to the recess to prevent rotation relative to the recess when disposed in the recess.

11. a first pulley coupled to the first and second wire segments, the first pulley being disposed between the first wire guide and the second wire guide; 10. The steering assembly of claim 2, further comprising a second pulley coupled to the third and fourth wire segments, the second pulley being disposed between the second wire guide and the third wire guide.

12. The steering assembly of claim 11 , wherein a thickness of the first pulley maintains the first and second gaps.

13. A steering assembly according to any one of claims 11 to 12, wherein a thickness of the second pulley maintains the third and fourth gaps.

14. 14. A steering assembly according to any one of claims 1 to 13, wherein the first wire guide has first and second offset surfaces that define first portions of the first and second gaps, respectively, and the second wire guide has third and fourth offset surfaces that define second portions of the first and second gaps, respectively.

15. 15. The steering assembly of claim 14, wherein the first wire guide has a first step surface extending from the first offset surface to the second offset surface, and the second wire guide has a second step surface extending from the third offset surface to the fourth offset surface, the first and second step surfaces defining third portions of the first and second gaps, respectively.

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