INSTRUMENT COUPLING INTERFACE AND ASSOCIATED METHODS - Patent application

Abstract

Disclosed herein are couplings and related methods that can provide for connecting a first object and a second object with minimal play. The coupling can include a first coupling component having a cylindrical surface with a screw and a pin extending therefrom, and a second coupling component having a prismatic surface with first and second through holes. The first and second coupling components can be configured such that when the screw is engaged with the first through hole to secure the cylindrical surface of the first component to the prismatic surface of the second component, relative motion between the first and second coupling components can be limited in all six degrees of freedom. The pin can be configured to maintain stability of the coupling and further limit relative motion, thereby minimizing misalignment and / or misorientation between the first and second components.

Description

[Technical field]

[0001] For example, disclosed herein are instrument coupling interfaces and associated methods for coupling a surgical instrument to a navigation array or other component. [Background technology]

[0002] Navigation or tracking of instruments during surgical procedures is becoming increasingly popular. Surgical navigation can help surgeons avoid delicate nerve or vascular structures when moving instruments within a patient. In spine surgery, for example, surgical navigation systems can be used during disc removal, bone drilling, implant insertion, e.g., screw and / or cage insertion, and other steps of the surgery. The use of surgical navigation systems can also reduce the amount of x-ray exposure to which patients and operating room staff are exposed, because procedures that do not utilize surgical navigation systems typically perform more steps using fluoroscopy or other x-ray-based imaging.

[0003] A typical navigation system includes an array of markers attached to a surgical instrument, an imaging system that captures images of the surgical field, and a controller that detects the markers in the captured images and tracks the movement of the markers within the surgical field. The controller relates the frame of reference of the imaging system to the frame of reference of the patient and, informed by the known geometry of the array and the instrument, determines how the instrument is moving relative to the patient. Based on that determination, the controller provides navigational feedback to the surgeon. The array can have different types or geometries, which can vary based on the navigation system, the type of surgery, and / or the location within the patient that is being tracked.

[0004] The accuracy of the navigation system is highly dependent on the design of the tracked instrument, particularly the stiffness of the interface between the navigation array and the rest of the instrument. Relatively high accuracy can be achieved by welding or integrally forming the navigation array to the instrument. However, such a solution can be inconvenient due to lack of ability to separate the array from the instrument or to couple the array to other instruments. Furthermore, an arrangement having a navigation array integrally formed with the instrument may require separate instruments for standard and navigational use, thereby increasing the cost of the equipment.

[0005] Several solutions have been developed that allow the navigation array to be interchangeably attached to one or more instruments. Such interchangeable connections can have a significant impact on the accuracy of instrument navigation. Interchangeable connections can include interfaces with dovetail or V-groove geometries for connecting the navigation array to the instrument. These solutions can be geometrically over-constrained, i.e., they can utilize more contact surfaces than necessary to constrain the movement of the two components. It can be difficult to reliably and repeatedly attach the array and the instrument in a desired relative position and orientation due to manufacturing tolerances and other variations that prevent a perfect fit between the many contact surfaces in such over-constrained configurations. Other variations can also be introduced into the interchangeable connections, such as mechanical deformations of one or more connection interfaces that can result from interactions between the components during use. In the case of over-constraining geometries, the more contact surfaces than necessary can increase the risk and impact of mechanical deformations. As a result, these solutions can allow situations in which the navigation array can move in one or more degrees of freedom, which can undesirably reduce the accuracy of the navigation. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, there is a need for improved devices, systems, and methods for securely joining a first object and a second object in a reliable, accurate, and repeatable relative position and orientation. [Means for solving the problem]

[0007] Disclosed herein is a coupling assembly that can provide a known and repeatable orientation of a first object and a second object while minimizing relative movement therebetween. The coupling can include a first coupling component having a cylindrical surface from which a screw and a pin extend, and a second coupling component having a prismatic surface, a first opening configured to receive the screw, and a second opening configured to receive the pin. In a fixed or mated configuration of the first and second coupling components, the screw can be threadably engaged with the first opening to fix the cylindrical surface against the prismatic surface, thereby forming two lines of contact therebetween. The pin can be received within the second opening of the second coupling component and can be configured to limit any relative movement between the first and second coupling components that is not blocked by the engagement of the screw.

[0008] In one aspect, a coupling for attaching a first object and a second object can include a first coupling component associated with the first object and a second coupling component associated with the second object. The first coupling component can have a cylindrical surface from which a screw and a pin extend. The second coupling component can have a prismatic surface, a first opening configured to receive the screw, and a second opening configured to receive the pin. The first and second components can be adapted to mate with one another such that relative motion between the first and second coupling components is limited in all six degrees of freedom.

[0009] The devices and methods described herein can have many additional features and / or variations, all of which are within the scope of the present disclosure. In some embodiments, for example, the pin can include a proximal end, a distal end, and a reduced diameter portion located proximal to the distal end of the pin. The distal end of the pin can be torus shaped. The first and second coupling components can be configured such that at least a portion of the reduced diameter portion of the pin is disposed within the second opening of the second coupling component when the first and second coupling components are mated. In some such embodiments, the pin can be configured to limit relative movement between the first and second coupling components along the longitudinal axis of the cylindrical surface.

[0010] The first and second coupling components can be configured such that when the pin of the first component is received within the second opening of the second component, a clearance exists between the pin and an inner surface of the second opening. In such an embodiment, a distal end of the pin can contact the inner surface of the second opening to limit movement of the second coupling component relative to the first coupling component.

[0011] In some embodiments, the first coupling component and the second coupling component can be adapted to mate with each other such that the first and second contact lines can extend between the first and second coupling components. The first and second contact lines can extend between a cylindrical surface of the first coupling component and a prismatic surface of the second coupling component. In particular, in some embodiments, the first and second contact lines can be located on either side of a center line of the cylindrical surface. The first and second contact lines can extend along substantially the entire length of the cylindrical surface.

[0012] The prismatic surface of the second coupling component can include a first end and a second end with a first sidewall and a second sidewall extending therebetween. The first sidewall and the second sidewall can extend at an angle relative to a backstop of the prismatic surface. A first contact line can extend along the first sidewall of the prismatic surface and a second contact line can extend along the second sidewall of the prismatic surface.

[0013] The screw of the first coupling component can include a post having a proximal end, a distal end, and a threaded portion located proximal to the distal end of the screw. The first coupling component can further include a back side opposite the cylindrical side, the back side being a flat planar surface. In some embodiments, the first coupling component can include a through hole configured to receive the screw such that the screw extends through the first coupling component perpendicular to the back side of the first coupling component. In some embodiments, the first object can be a surgical instrument and the second object can be a navigation array.

[0014] In another aspect, a method of coupling a first object and a second object is provided that can include aligning a first coupling component associated with the first object and a second coupling component associated with the second object. The first coupling component can have a cylindrical surface with a screw and a pin extending therefrom, and the second coupling component can have a prismatic surface, a first opening, and a second opening. The method can include advancing the first coupling component relative to the second component such that the cylindrical surface is seated against the prismatic surface, the screw is received in the first opening, and the pin is received in the second opening. The method can further include locking the first coupling component and the second coupling component in a mating configuration such that relative movement between the first coupling component and the second coupling component is limited in six degrees of freedom.

[0015] The method may further include limiting relative movement between the first and second components by contact between the pin and an inner surface of the second opening. Fixing the first and second components may further include driving a screw in the first opening. In some embodiments, driving the screw may prevent relative movement between the first and second components in at least five degrees of freedom. The method may further include, after driving the screw to fixate the first and second components, a pin may limit relative movement between the first and second components. In some such embodiments, the pin may contact an inner surface of the second opening to limit relative movement between the first and second components. The limited relative movement between the first and second components may be along a longitudinal axis of the cylindrical surface.

[0016] Driving the screw to mate the first and second components can include rotating the screw in a first direction such that a threaded portion of the screw fully engages with a threaded inner surface of the first opening. In some such embodiments, when the screw fully engages with the threaded inner surface of the first opening, an unthreaded distal end of the screw can extend beyond a back surface of the second component.

[0017] In some embodiments, driving the screw to mate the first component and the second component can include rotating a handle of the screw assembly in a first direction until a planar surface of the handle abuts a back surface of the first component.

[0018] The first and second components can contact each other along first and second contact lines that extend between the cylindrical surface of the first component and the prismatic surface of the second component, hi some such embodiments, the first and second contact lines can be located on opposite sides of a centerline of the cylindrical surface.

[0019] Any of the above-described features or variations may be applied to any particular aspect or embodiment of the present disclosure in many different combinations, and no explicit description of any particular combination is provided, simply to avoid redundancy in this summary. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is an exploded perspective view of a prior art coupling. [Diagram 2] FIG. 2 is another view of the prior art coupling of FIG. 1. [Diagram 3] 1 illustrates an embodiment of a navigated instrument system including an embodiment of a coupling according to the present disclosure. [Figure 4] FIG. 4 is a perspective view of a first coupling component in the system shown in FIG. 3. [Diagram 5] FIG. 5 is a perspective view of a screw assembly of the first coupling component shown in FIG. 4. [Figure 6] FIG. 4 is a perspective view of a second coupling component of the system shown in FIG. 3. [Figure 7] 7 is a cross-sectional perspective view of the second coupling component of FIG. 6 taken along line AA of FIG. 6. [Figure 7A] 7 is another cross-sectional view of the second coupling component of FIG. 6 taken along line AA of FIG. 6. [Figure 8] FIG. 4 is a perspective view of the first coupling component and the second coupling component of the system shown in FIG. 3 in a mated configuration. [Figure 9] FIG. 1 is a schematic diagram of the mechanical principle of a coupling according to the present disclosure. [Figure 10] 9 is a cross-sectional view of the coupling of FIG. 8 taken along line BB of FIG. 8. [Figure 11] 9 is another cross-sectional view of the coupling of FIG. 8 taken along line CC of FIG. 8. [Figure 12] 4 is a cross-sectional view of the coupling of the system shown in FIG. 3 showing the first coupling component and the second coupling component in ideal alignment in a mated configuration. [Figure 13] 4 is a cross-sectional view of the first coupling component and the second coupling component of the system shown in FIG. 3 in non-parallel alignment in a mated configuration. [Figure 13A] FIG. 14 is an enlarged view of the coupling shown in FIG. 13. [Figure 14] FIG. 4 is a perspective view of the coupling of the system of FIG. 3, with the first coupling component seated within the second coupling component. [Figure 15] FIG. 4 is a perspective view of the coupling of the system of FIG. 3 with the first coupling component mated to the second coupling component. [Figure 16] FIG. 4 is a perspective front view of a navigation array in relation to a second coupling component of the system of FIG. 3. [Figure 17] FIG. 17 is a perspective rear view of the navigation array of FIG. 16. [Figure 18] FIG. 4 is a perspective view of an instrument adapter associated with a first coupling component of the system of FIG. [Figure 19] FIG. 19 is a side view of the instrument adapter of FIG. [Figure 20] FIG. 19 is an alternative perspective view of the instrument adapter of FIG. [Figure 21] FIG. 19 is a front view of the instrument adapter of FIG. [Figure 22] FIG. 4 is a perspective view of the system of FIG. 3 with a first object associated with the first coupling component aligned with a second object associated with the second coupling component. [Figure 23] FIG. 4 is an alternative perspective view of the system of FIG. 3, in which a first object associated with a first coupling component is aligned with a second object associated with a second coupling component. [Figure 24] FIG. 4 is a perspective view of the system of FIG. 3 with a first coupling component associated with a first object seated within a second coupling component associated with a second object. [Diagram 25]FIG. 4 is a side view of the system of FIG. 3 with a first coupling component associated with a first object seated within a second coupling component associated with a second object. [Figure 26] FIG. 4 is a perspective view of the system of FIG. 3, with a first coupling component associated with a first object secured to a second coupling component associated with a second object. [Figure 27] FIG. 4 is an alternative perspective view of the system of FIG. 3, in which a first coupling component associated with a first object is secured to a second coupling component associated with a second object. [Figure 28] 4 is a side view of the system of FIG. 3, with a first coupling component associated with a first object secured to a second coupling component associated with a second object. [Figure 29] FIG. 4 is a front view of the system of FIG. 3, with a first coupling component associated with a first object secured to a second coupling component associated with a second object. [Diagram 30] FIG. 4 is a top view of the system of FIG. 3, with a first coupling component associated with a first object secured to a second coupling component associated with a second object. [Diagram 31] 1 illustrates an alternative embodiment of a coupling according to the present disclosure. [Diagram 32] 32 shows the coupling of FIG. 31 in a mated configuration. [Diagram 33] 32 shows the coupling of FIG. 31 in a mated configuration with a first object associated with the first coupling component and a second object associated with the second coupling component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] For example, an instrument coupling interface and associated methods for coupling a surgical instrument to a navigation array or other component are disclosed herein. An embodiment of the presently disclosed coupling can include a first coupling component associated with a first object, such as a surgical instrument or a surgical instrument adapter, and a second coupling component associated with a second object, such as a navigation array. The first coupling component can be configured to mate with the second coupling component such that the first object and the second object are disposed in a known position and orientation relative to one another with minimal play or capacity for relative movement. The coupling can be fully defined, i.e., can constrain movement in all six degrees of freedom, without having an overly constraining geometry that utilizes more contact surfaces than necessary to achieve the desired movement confinement. Thus, the coupling can minimize or eliminate navigational inaccuracies associated with system tolerances of objects and / or components in the navigated instrument system.

[0022] Prior Art Coupling 1 and 2 show a prior art coupling 100 for attaching two objects. The coupling 100 includes a first component 102A associated with a first object A and a second component 102B associated with a second object B. The first component 102A includes four V-shaped protrusions 104 that are received in four corresponding V-shaped recesses 106 of the second component 102B. The illustrated coupling 100 has an over-constraining geometry in that there are more contact points or contact surfaces than are necessary to constrain the objects A, B in the desired degree of freedom (i.e., the illustrated coupling 100 includes at least eight possible contact surfaces between the first and second components 102A, 102B). The number of protrusions and corresponding recesses can be three or more. In such a configuration, it is possible that the case may be that not all eight contacting surfaces are actually in contact with each other, which may allow for some degree of "play" or backlash or relative movement between the first object A and the second object B (e.g., due to the gap 110 between them, as shown in FIG. 2). In addition, conical or V-shaped surfaces may be very sensitive to tolerances, which may lead to varying gap sizes when mating components are brought together. As a further example, variations in geometry between objects or parts intended to have identical coupling interfaces may prevent the achievement of a repeatable known position and orientation between the two mating objects. This risk is exacerbated by over-constrained or over-constrained couplings that have more contact points than necessary. Given the constraints of such couplings, tolerances must be tightly controlled, which may increase manufacturing costs, reduce manufacturing yields, or a certain level of imprecision must be accepted. Additionally, interactions between components with many small interface features and / or sharp edges or surfaces, such as the multiple V-shaped protrusions shown in Figures 1 and 2, can result in one or more components in the coupling experiencing mechanical deformation or wear.Such mechanical deformation or wear can result in imperfect coupling and undesirable relative movement between the components. Although Figures 1 and 2 show coupling with a V-groove geometry, dovetail and other types of connections can also impose over-constraints and suffer from the above inaccuracies.

[0023] INSTRUMENT COUPLING INTERFACE AND ASSOCIATED METHODS - Patent application Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will appreciate that the devices, systems, and methods described in detail herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. Features shown or described in connection with one embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be within the scope of the present disclosure.

[0024] Additionally, to the extent that linear or circular dimensions are used in the description of the disclosed devices and methods, such dimensions are not intended to limit the types of shapes that may be used with such devices and methods. Those skilled in the art will recognize that equivalent dimensions of such linear and circular dimensions may be determined for different geometric shapes. Furthermore, in this disclosure, like-numbered components of the embodiments generally have similar characteristics. Still further, the size and shape of the device and its components may depend at least on the anatomy of the subject with whom the device is used, the size and shape of the object with which the device is used, and the method and procedure with which the device is used.

[0025] FIG. 3 illustrates an embodiment of a navigated instrument system 300 including a coupling 308 capable of mating a first object (e.g., instrument adapter 302) to a second object (e.g., navigation array 304). The instrument adapter 302 can be configured to receive an instrument 306 therein. The navigation array 304 and instrument 306 can be positioned within a field of view of a navigation system 307. The navigation array 304 can be detected by, in communication with, or otherwise operably coupled to the navigation system 307, thereby allowing the position and / or orientation of an instrument (e.g., instrument 306 and / or instrument adapter 302) attached to the navigation array 304 by the coupling 308 to be aligned with and tracked by the navigation system. The coupling 308 can achieve consistent relative positions of the first and second objects with greater stability than conventional couplings and may be less prone to errors introduced by system tolerances (e.g., manufacturing tolerances when fabricating various components of the system). Coupling 308 can couple navigation array 304 to instrument adapter 302 and / or instrument 306 in a known, repeatable position with minimal play or capacity for relative movement between them. Thus, coupling 308 can improve the accuracy and reliability of navigation of instrument 306 by more effectively coupling the two components into a single, rigid construct.

[0026] The coupling 308 can be configured to provide a toggle-free, fully oriented coupling while the relative movement between the coupled components is limited in all six degrees of freedom. As shown in more detail in the insert box 3A, the coupling 308 can include a first coupling component 310 associated with a first object (e.g., the instrument adapter 302) and a second coupling component 312 associated with a second object (e.g., the navigation array 304). The first coupling component 310 and the second coupling component 312 can be integrally formed with the first object 302 and the second object 304, respectively. For example, the coupling components associated with the first or second object can be manufactured directly on the surface of the object itself. Alternatively, the first and / or second coupling components can be separate components that are welded, screwed, glued, or otherwise securely associated or attached to the first and second objects, respectively.

[0027] The first coupling component 310 can be configured to mate with the second coupling component 312 to couple the first and second objects with minimal play or ability for relative movement between them. The first coupling component 310 and the second coupling component 312 can be fixed or mated to each other with relative movement between them limited in all six degrees of freedom. As discussed in detail below, the coupling 308 can provide a fully defined connection between the first and second components 310, 312 based on a cylindrical surface of the first coupling component 310 that seats against a prismatic surface of the second component 312 and can be further secured by a screw. A pin extending from the first coupling component 310 can add stability to the coupling 308 and further limit movement between the two components. The coupling 308 can have good durability and can reduce the risk of mechanical deformation to the coupling components 310, 312, for example, by eliminating contact of sharp surfaces or edges and minimizing interaction between the components during coupling and uncoupling.

[0028] A coordinate system will now be described in relation to coupling 308, which will be used throughout this disclosure to aid in the description of the couplings and related methods disclosed herein. A Z-axis 314 may extend along the longitudinal axis of the cylindrical surface of first component 310. A X-axis 316 may extend perpendicular to the back surface of first coupling component 310. In the illustrated assembly, the X-axis may extend along the longitudinal axis of instrument adapter 302. A Y-axis 318 may extend perpendicular to both the X-axis and Z-axis and may traverse first coupling component 310 (i.e., the Y-axis may extend along the width of first component 310, as described below). The coordinate system is shown in box 350, which is reproduced throughout the figures for reference.

[0029] 4-7 show components of coupling 308 in more detail. FIG. 4 shows a first coupling component 310 (also referred to herein as the first component). The first coupling component 310 can include a cylindrical surface 404, threads 410, and a pin 412. The threads 410 and the pin 412 can extend from the cylindrical surface 404. The cylindrical surface 404 can have a convex profile and can extend along a substantial portion of the first coupling component 310.

[0030] In some embodiments, the first coupling component 310 can include a first end portion 406 proximal to the proximal end 404p of the cylindrical surface 404 and a second end portion 408 distal to the distal end 404d of the cylindrical surface 404. The cylindrical surface 404 can extend over a length L1 between the first end portion 406 and the second end portion 408. In some embodiments, the length L1 of the cylindrical surface 404 can extend over a substantial portion of the length of the first coupling component 310. The first end portion 406 and the second end portion 408 can have planar surfaces. In some embodiments, the end portions 406, 408 can facilitate manufacturing of the first component 310. For example, the first coupling component 310 can have chamfered edges, which can be more easily manufactured from planar surfaces (i.e., the planar surfaces of the first and second end portions 406, 408) than curved surfaces. The end portions 406 , 408 may correspond to the geometry of the second coupling component 312 and may aid in aligning the first coupling component 310 with the second coupling component 312 .

[0031] As described in detail below, the cylindrical surface 404 can be configured such that when the first coupling component 310 is secured to the second coupling component 312, two contact lines can extend between the cylindrical surface 404 and the second coupling component 312. Each of the two contact lines can be a continuous line. In some embodiments, each contact line can extend along the entire length L1 of the cylindrical surface 404 or substantially along the entire length L1. For example, when the first component 310 is secured to the second component 312, the first contact line 303A can extend along the left side of the cylindrical surface 404 (with respect to a midline ML of the cylindrical surface extending along the Z axis) when viewed in the perspective view of FIG. 4. The second contact line 305A can extend along the right side of the cylindrical surface 404 (with respect to a midline ML of the cylindrical surface) when viewed in the perspective view of FIG. 4.

[0032] The screw 410 and pin 412 can extend from the cylindrical surface 404 of the first coupling component 310. More specifically, the screw 410 and pin 412 can extend from the cylindrical surface 404 along the X-axis of the first component 310. In some embodiments, the screw 410 and pin 412 can be centered with respect to a midline ML of the cylindrical surface 404. The screw 410 and pin 412 can be configured to be received within a corresponding opening in the second component 312. In some embodiments, the screw 410 and pin 412 can extend from a planar surface 416 that can be formed or fitted into the cylindrical surface 404. In other embodiments, one or both of the screw 410 and pin 412 can extend from a convex portion of the cylindrical surface 404. Although the illustrated embodiment shows the screw 410 disposed proximally of the pin 412 (i.e., closer to the proximal end 404p of the cylindrical surface), alternative configurations are within the scope of this disclosure. For example, in some embodiments, the pin 412 can be located proximal to the screw 410 .

[0033] The screw 410 can be part of a screw assembly 414, which is disposed in a through hole of the first component 310. As shown in FIG. 4, only the distal end of the pin 410 extends through the through hole opening of the first component 310. This can indicate that the screw assembly 414 has not yet been fully tightened relative to the first component 310. In comparison, the first component 310 shown in FIG. 3 shows the screw assembly 414 in a tightened configuration relative to the first component. The pin 412 can be integrally formed with the first component 310. In other embodiments, the pin 412 can be a separate component that can be welded, threaded, glued, or otherwise associated or attached to the first component 310 such that the pin 412 extends along the X-axis of the first component.

[0034] FIG. 5 illustrates the screw assembly 414 of the first component 310. The screw assembly 414 can include a screw 410 and a handle 418. The screw 410 can include a post 420 having a threaded portion 422. The threaded portion 422 can have threads that correspond to the threaded inner surface of the opening of the second component 312. In some embodiments, the threaded portion 422 can extend from a proximal end 422p to a distal end 422d. The distal end 422d of the threaded portion 422 can be located proximal to the distal end 420d of the post 420. In other words, the distal end 420d of the post 420 can be unthreaded and, in some embodiments, can take the form of an unthreaded cylinder. The distal surface 421 of the screw 410 can be a planar surface. The unthreaded distal end 420d of the screw 410 can aid in alignment and facilitate assembly of the screw 410 with a corresponding opening in the second component 312 (e.g., the unthreaded distal portion 420d can aid in aligning the screw before the threads engage to prevent cross-threading due to misalignment). The screw post 420 can extend from a planar outer surface 424 of the handle 418. As described in more detail below, the planar surface 424 can be configured to abut a planar underside of the first component 310. In some embodiments, the screw 410 can be integrally formed with the handle 418. In other embodiments, the screw 410 and the handle 418 can be separate pieces that can be securely attached to one another. For example, the screw 410 can be attached to the handle 418 using an assembly pin 426.

[0035] One or more wings 428 can be formed on the handle 418. The wings 428 can facilitate an easy and secure grip of the handle 418 for, for example, turning the screw 410 by a user. One or more openings 430 can be formed in the handle 418. In some embodiments, an instrument can be inserted through one or more of the openings 430 and can provide increased torque to assist in turning the handle, i.e., tightening or loosening the screw 410. For example, a rod (not shown) can be inserted through the opposing openings 430 to provide a larger lever arm, thereby increasing the torque that a user can apply to the handle 418.

[0036] 6 and 7 show the second coupling component 312 in more detail. FIG. 6 shows a perspective view of the second coupling component 312 (also referred to herein as the second component). The second coupling component 312 can have a prismatic surface 502 having a first end 504, a second end 506, and opposing first and second sides 508, 510 extending therebetween. In some embodiments, the planar surface 512 can form a backstop in the prismatic surface 502. The planar surface 512 can facilitate manufacturing of the second component 312 and the prismatic surface 502.

[0037] The prismatic surface 502 can be configured to receive the cylindrical surface 404 of the first component 310 within a recess defined by the prismatic surface 502. As described above, in a fixed or mated configuration of the first and second components 310, 312, two contact lines can extend between the cylindrical surface 404 and the second coupling component 312. More specifically, the two contact lines can extend between the prismatic surface 502 of the second coupling component 312 and the cylindrical surface 404 of the first coupling component 310. For example, when the first component 310 is mated with the second component 312, the first contact line 303B can extend along the second side 510 of the prismatic surface 502, which can correspond to the first contact line 303A, which can extend along the cylindrical surface 404. The second contact line 305B can extend along the first side 508 of the prismatic surface 502, which can correspond to the second contact line 305A, which can extend along the cylindrical surface 404. In some embodiments, the first contact line 303B and the second contact line 305B can extend along the entire length or substantially the entire length of the second side 510 and the first side 508, respectively. The first end 504 and the second end 506 of the second component 312 can be configured to receive the first end portion 406 and the second end portion 408 of the first coupling component 310, respectively. In some embodiments, the first end 504 and the second end 506 can include chamfered corners that can complement the geometry of the first end portion 406 and the second end portion 408 of the first coupling component 310.

[0038] The second component 312 can include a first opening 514 and a second opening 516. In some embodiments, the first opening 514 and the second opening 516 can be through holes extending through the second coupling component 312. The first opening 514 can be configured to receive the screw 410 of the first coupling component 310. Thus, the first opening 514 can have a threaded inner surface 518. The threads of the threaded inner surface 518 can correspond to the threads of the threaded portion 422 of the screw 410. The second opening 516 can be configured to receive the pin 412 of the first coupling component 310. In some embodiments, the second opening 516 can have a smooth or unthreaded inner surface 517. As shown in the illustrated embodiment, the diameter of the first opening 514 can be larger than the diameter of the second opening 516. In other embodiments, the diameter of the first opening 514 can be equal to or smaller than the diameter of the second opening 516. The first opening 514 and the second opening 516 can be formed in the second component 312 to correspond to the screws 410 and the pins 412, respectively, of the first component 310. Thus, in some embodiments, the first opening 514 and the second opening 516 can have a different configuration, positioning, or dimensions than those of the illustrated embodiment to appropriately correspond and complement the screws 410 and the pins 412.

[0039] FIG. 7 shows a perspective view of a cross section of the second component 312 taken along line AA in FIG. 6. The back surface 520 of the second coupling component 312 can be a planar back surface. In some embodiments, the planar back surface 520 can extend parallel to the backstop 512. FIG. 7A shows another view of the cross section of the second component 312 taken along line AA in FIG. 6. As seen in FIG. 7A, the first side 508 and the second side 510 of the prismatic surface 502 can extend at angles α2 and α1, respectively, with respect to the Y axis of the second component 312 (i.e., with respect to an axis extending perpendicular to the longitudinal axis of the first opening and transverse to the longitudinal axis of the prismatic surface). The angle α2 of the first side 508 can be the same as the angle α1 of the second side 510. However, in some embodiments, the angle α2 of the first side 508 and the angle α1 of the second side 510 can be different. The angles α1, α2 can be selected such that when the first component 310 and the second component 312 are mated, the prismatic surface 502 can be configured to maintain two contact lines with the cylindrical surface 404 of the first component 310. In some embodiments, the angles α1, α2 can be selected such that the first contact line and the second contact line between the cylindrical surface 404 and the prismatic surface 502 can be as far apart as possible for a stable bond. As non-limiting examples, the angles α1, α2 can each be about 30°, about 45°, or about 60°. Other angles α1, α2 less than about 90° are also possible. In some embodiments, the angles α1, α2 can each be about 30°, which can be easier to manufacture. The angles α1, α2 can each be selected such that the crossing angle α3 can be about 30° to about 120°.

[0040] FIG. 8 illustrates the coupling 308 in a fixed or mated configuration, with a first component 310 coupled to a second component 312. In the mated configuration, the cylindrical surface 404 of the first coupling component 310 can be fixed within a recess formed by a prismatic surface 502 of the second coupling component 312. The threads 410 of the first component 310 can be threadingly engaged with a first opening 514 of the second component 312, bringing the first component 310 and the second component 312 into perfect or parallel alignment. To that end, the planar back surface 432 of the first coupling component 310 and the planar back surface 520 of the second coupling component 312 can be aligned parallel to one another. Additionally, in the mated configuration, the pin 412 can be received within a second opening 516 of the second coupling component 312. As described in more detail below, the pin 412 can limit relative movement between the first coupling component 310 and the second coupling component 312 that may exist due to frictional forces and / or tolerance variations, for example, when the first component 310 and the second component 312 are aligned by the screw 410. The pin 412 can also function to provide additional stability to the coupling 308.

[0041] FIG. 9 shows a schematic of the mechanical principle of the coupling 308. More specifically, FIG. 9 shows how various degrees of freedom can be locked or limited by embodiments of the coupling 308. The component with the cylindrical surface 12, the component with the prismatic surface 14, the screw 16, and the pin 18 in FIG. 9 can respectively represent the first component 310 with the cylindrical surface 404, the second component 312 with the prismatic surface 502, and the screw 410 and the pin 412 of the coupling 308. FIG. 9 shows a coordinate system with axes X′, Y′, and Z′ that can be similarly defined for the component with the cylindrical surface 12 as a coordinate system with axes X, Y, and Z, as described herein for the coupling 308.

[0042] As shown in box 10, the cylindrical surface 12 seated in the recess formed by the prismatic surface 14 can limit movement along the X' and Y' axes and rotation about the X' and Y' axes. Translation along the Z' axis, i.e., the longitudinal axis of the cylindrical surface 12, and rotation about the Z' axis can remain free. Box 20 shows diagrammatically the effect of a screw 16 disposed in a through hole of a component having the cylindrical surface 12 and threadingly engaged with an opening of a component having the prismatic surface 14. The screw can block relative translation along the X' and Y' axes, as well as relative rotation about all three axes (X', Y', and Z'). Furthermore, the screw 16 can function to at least limit, if not block, relative translation along the Z' axis. However, in some cases, although relative movement along the Z' axis can be limited by the screw 16, the possibility of relative translation along the Z' axis can still exist, for example due to frictional forces. The pin 18 extends from the cylindrical surface 12 and may be received within an aperture in a component having a prismatic surface 14. As shown in box 30, the pin 18 received within the aperture may be restricted in translation along and rotation about the Y' and Z' axes, but is free to translate along and rotate about the X' axis. Thus, the coupling 308 may limit relative movement in all six degrees of freedom, as shown diagrammatically in FIG. 9.

[0043] Returning to FIG. 8 , the cylindrical surface 404 can seat within a recess formed by the mating prismatic surface 502 to limit relative movement along and rotation about the X and Y axes. As described further herein, the screw 410 can threadably mate with a first opening 514 of the second component 312 to block relative movement between the first component 310 and the second component 312 in at least five degrees of freedom. The pin 412 can be received within a second opening 516 of the second component 312 to further limit relative movement between the first component 310 and the second component 312 such that relative movement between the first component 310 and the second component 312 is blocked in all six degrees of freedom.

[0044] The contact line 305 can extend along the Z-axis between the first component 310 and the second component 312. More specifically, the contact line 305 can extend between the cylindrical surface 404 of the first coupling component 310 and the prismatic surface 502 of the second coupling component 312. For example, the contact line 305 can correspond to the second contact lines 305A, 305B shown on the first coupling component 310 in FIG. 4 and the second component 312 in FIG. 6, respectively. Although not visible in FIG. 8, an additional contact line can extend between the first component 310 and the second component 312 on a side of the coupling 308 opposite that of the contact line 305 (e.g., corresponding to the first contact lines 303A, 303B shown in FIGS. 4 and 6, respectively). It will be understood that the illustrated contact lines (e.g., 305, 305A, 305B, 303, 303A, 303B) represent contact between the first coupling component 310 and the second coupling component 312 when mated. Thus, the exact location of the contact lines can be a function of the geometry of the first coupling component 310 and the second coupling component 312, and more specifically, the geometry of the cylindrical surface 404 of the first coupling component 310 and the prismatic surface 502 of the second coupling component 312. Thus, alternative locations of the contact line or lines other than those shown in the figures are possible and can be within the scope of the present disclosure.

[0045] The coupling 308 may include an identification pin 802 that may be used as an indicator to prevent misassembly of the coupling 308. The identification pin 802 may be received within a corresponding opening on the back surface 520 of the second coupling component 312. The identification pin 802 may serve as a visual identifier for the bottom end of the second component 312 to prevent improper assembly of the second coupling component 312 with the first coupling component 310. Improper assembly of the coupling 308 may cause the screw 410 to be improperly aligned with the second opening 516 and the pin 412 to be improperly aligned with the first opening 514. Thus, the identification pin 802 may aid in "error-proof" assembly, i.e., preventing inadvertent errors or mistakes in the assembly of the coupling 308.

[0046] Additionally, the identification pin 802 can also serve to identify a particular characteristic of the second object 304 associated with the second coupling component 312. As a non-limiting example, the identification pin 802 can be a color-coded pin, with a particular color identifying a particular size of the navigation array 304 (or other second object that can be associated with the second coupling component 312). In some embodiments, the entire navigation array 304 can be color-coded (e.g., coated, stained, anodized, etc.) to identify the array or a particular characteristic of the array. In this manner, a user can quickly verify that the intended and properly sized navigation array 304 is coupled to the first object (e.g., the instrument adapter 302) for a particular application. As can be seen in more detail in FIG. 10, the pin-receiving opening 804 can extend from the back surface 520 of the second component 312. The opening 804 can be a blind hole such that the pin 802 can be received within the second component 312 without interfering with the prismatic surface 502 of the second coupling component 312. In some embodiments, the identification pin 802 and the opening 804 can have corresponding threads that can engage to secure the identification pin 802 within the opening 804 .

[0047] FIG. 10 shows a cross-sectional view of the coupling 308 in full or parallel alignment taken along line BB in FIG. 8. In the illustrated cross-section, the first component 310 and the second component 312 are shown mated such that the coupling 308 can constrain relative movement between the first component 310 and the second component 312 in all six degrees of freedom with minimal play. The first component 310 and the second component 312 can be aligned in parallel by the screw 410 engaged with the first opening 514 of the second component 312. More specifically, the threaded portion 422 of the screw 410 can be fully threadably engaged with the threaded inner surface 518 of the first opening 514 of the second component 312. In some embodiments, the first coupling component 310 and the second coupling component 312 can be fully coupled when the threaded portion 422 of the screw 410 is fully threadably engaged with the threaded inner surface 518 of the first opening 514. In such a configuration, the distal end 420 d of the screw 410 can extend beyond the back surface 520 of the second component 312 .

[0048] The screw 410 can extend perpendicular to the planar surface 424 of the handle 418. An assembly pin 426 can secure the screw 410 within the handle 418 to ensure a perpendicular relationship between the screw 410 and the planar surface 424. Alternatively, the screw 410 and the handle 418 can be formed in a single piece such that the screw assembly 414 is a single component. Regardless of manufacture, the screw 410 can extend perpendicular to the planar surface 424 of the handle 418, which allows the screw assembly 414 to secure the first component 310 and the second component 312 in parallel alignment with each other in a mated configuration. In some embodiments, the handle 418 can be sized for an optimal depth of engagement with the screw 410, and more specifically, the screw post 420. In other words, the handle 418 can be sized to maximize contact with the screw post 420 over the entire length of the handle 418. By optimizing the engagement between the screw post 420 and the handle 418, misorientation of the screw 410 relative to the handle 418 can be reduced.

[0049] The screw 410 may engage the first opening 514 to place the first component 310 and the second component 312 in a mating configuration such that the planar surface 424 of the handle 418 is aligned with and adjacent to the planar back surface 432 of the first component 310. The screw 410 may be disposed within the through hole 409 of the first component 310. A central longitudinal axis of the through hole 409 may be perpendicular to the planar back surface 432 of the first component 310. Thus, the screw assembly 414 may secure the cylindrical surface 404 of the first component 310 against the prismatic surface 502 of the second component 312. As shown in FIG. 10 , the engagement of the screw 410 with the first opening 514 may align the first component 310 and the second component 312 parallel to one another.

[0050] The threaded engagement of the screw 410 with the first opening 514 of the second component 312 can block relative movement between the first component 310 and the second component 312 in at least five degrees of freedom. The screw 410 can block translation along the X-axis and the Y-axis and rotation about the X-axis and the Y-axis. The threadedly engaged screw 410 can also block rotation between the first component 310 and the second component 312 about the Z-axis. Furthermore, the screw 410 can function to at least limit, if not block, relative translation of the first component 310 and the second component 312 along the Z-axis. However, in some examples, although relative movement along the Z-axis can be limited by the screw 410, the possibility of relative translation along the Z-axis can still exist, for example, due to frictional forces between the first component 310 and the second component 312.

[0051] The pin 412 can be received within a second opening 516 of the second coupling component 312. The pin 412 can be configured to further limit relative movement along the Z axis, which can leave minimal play between the first coupling component 310 and the second coupling component 312. More specifically, the pin 412 and the second opening 516 can be configured such that there is only a small clearance between the pin and an inner surface 517 of the second opening 516. Thus, relative movement along the Z axis between the second component 312 and the first component 310 can be limited to the amount the second component 312 can move before the inner surface 517 of the second opening 516 contacts the pin 412. Similarly, the pin 412 can also function to limit relative movement along the Y axis and rotation about the Y and Z axes.

[0052] 11 shows a cross-sectional view of the coupling 308 taken along line CC in FIG. 8. In the depicted view, the pin 412 can be seen to extend perpendicularly from the first component 310. The pin 412 can be received within the second opening 516 of the second component 312 such that the distal surface 1002 of the pin 412 can be flush with the back surface 520 of the second component 312. In some embodiments, the distal end 412d of the pin 412 can have a torus shape with a planar distal surface 1002. The torus shape of the distal end 412d can allow for easier manufacturing than a distal end of another geometric shape, such as a sphere, although in other embodiments, different distal end shapes, such as a sphere, are possible. The proximal end 412p of the pin 412 may be seated within the first component 310 such that the pin 412 extends perpendicular to the back side 432 of the first component 310 (i.e., the pin 412 may extend from the first component 310 along its X-axis). In the illustrated embodiment, the pin 412 may be a separate component that may be welded to the first component 310. As mentioned above, in other embodiments, the pin 412 may be threaded, glued, or otherwise securely attached to the first component 310. Alternatively, the pin 412 may be integrally formed with the first component 310.

[0053] The pin 412 can have a reduced diameter portion 1004 that can be proximal to the distal end 412d of the pin. The pin 412 can include an undercut from the distal end 412d to the reduced diameter portion 1004 such that the diameter of the reduced diameter portion 1004 is smaller than the diameter of the distal end 412d of the pin. Similarly, there can be an undercut from the proximal portion 412p of the pin to the reduced diameter portion 1004. As described in more detail below, the reduced diameter portion 1004 can provide compensation for tolerance and positioning variations between the first component 310 and the second component 312, if necessary, and can ensure that two contact lines remain between the cylindrical surface 404 and the prismatic surface 502 despite such variations. The reduced diameter portion 1004 can be formed such that when the pin 412 is received within the second opening 516, the reduced diameter portion 1004 is longitudinally aligned with a substantial portion of the second opening 516. More specifically, the reduced diameter portion 1004 can be aligned with the proximal end 516p of the second opening 516 and extend longitudinally toward the distal end 516d of the second opening.

[0054] 11 illustrates two contact lines between the first coupling component 310 and the second coupling component 312 in a mated configuration. The coupling 308 can be configured such that with the first component 310 secured to the second component 312, contact between the cylindrical surface 404 of the first component 310 and the prismatic surface 502 of the second component 312 occurs only along the first and second contact lines 303, 305. The first contact line 303 can extend between the cylindrical surface 404 of the first component 310 and the sidewall 510 of the prismatic surface 502 of the second coupling component 312. The first contact line 303 can extend along the left side of the cylindrical surface 404 relative to the centerline of the cylinder when viewed from the perspective view of FIG. 11. The second contact line 305 can extend between the cylindrical surface 404 and the sidewall 508 of the prismatic surface 502 of the second coupling component 312. The second contact line 305 can extend along the right side of the cylindrical surface 404 relative to the centerline of the cylinder when viewed from the perspective view of FIG. 11. The contact lines 303, 305 can be spaced apart from one another, for example, on opposite sides of the cylindrical surface 404 and the prismatic surface 502, thereby providing increased stability in the coupling 308. As a non-limiting example, in the illustrated embodiment, the cylindrical surface 404 and the prismatic surface 502 can be configured such that the distance between the first and second contact lines 303, 305 can be from about 5 mm to about 12 mm. In some embodiments, the distance between the contact lines 303, 305 can be about 9 mm. However, in other embodiments, different distances can be possible based on the size of the components being joined, etc.

[0055] As mentioned above, the location of the contact lines 303, 305 can be a function of the geometry of the first coupling component 310 and the second coupling component 312. Thus, the contact lines 303, 305 can be at different locations on the cylindrical surface 404 and the prismatic surface 502 than those shown in the figures. For example, a cylindrical surface 404 with a smaller radius can cause the first contact line 303 and the second contact line 305 to be located closer to the center line of the cylindrical surface 404 than those shown in FIG. 11. The stability of the coupling can be compromised if the radius of the cylindrical surface 404 is too small because any toggling or tilting of the second component 312 relative to the first component 310 can result in dramatic or unbalanced movement of the second component 312 along the cylindrical surface 404. Conversely, a cylindrical surface 404 with a larger radius may cause the first and second contact lines 303, 305 to be located farther from the centerline of the cylindrical surface 404 than shown in Figure 11. If the radius of the cylindrical surface 404 is too large, the portion of the cylindrical surface 404 that is intended to be received within the recess of the prismatic surface 502 may approximate a flat surface, thereby preventing the intended coupling. The angle of the prismatic surface 502 (e.g., angles α1, α2, and / or α3) may also affect the location of the first and second contact lines 303, 305.

[0056] The geometry of the cylindrical surface 404 and / or the prismatic surface 502 can be adjusted based on factors such as application requirements and / or manufacturing constraints, as long as, in a mating configuration, the first and second contact lines extend between the cylindrical surface 404 of the first coupling component 310 and the prismatic surface 502 of the second coupling component 312. In some embodiments, the cylindrical surface 404 and the prismatic surface 502 can be designed to allow the contact lines 303, 305 to be located as far away as possible while still maintaining a stable coupling. There may be a direct relationship between the diameter of the cylindrical surface 404 and the rotation error of the coupling 308 (i.e., the rotation error may increase with an increase in the diameter of the cylindrical surface 404). Thus, the diameter of the cylindrical surface 404 may be optimized according to the design of the prismatic surface 502 to have an acceptable amount of rotation error for a particular use. Additional factors that may be considered when determining the geometry of the coupling 308 may include the relationship between the angle of the prismatic surface 502 and the resulting height of the coupling 308, and the length of the contact lines 303, 305, as well as the stability and manufacture of the coupling 308. More specifically, increasing the angles α1, α2 of the prismatic surface 502 may increase the height of the coupling 308. In one embodiment, the angles α1, α2 may be approximately 30°, which may result in a coupling 308 having an appropriate size and weight (e.g., a lightweight coupling 308 that may be used to couple a lightweight navigation array to an object). The length of the contact lines 303, 305 may contribute to the stability of the coupling 308, but manufacturing the cylindrical surface 404 and / or the prismatic surface 502 may become more difficult as the length of the surfaces 404, 502 increases.

[0057] 12, 13, and 13A illustrate how the pin 412 can be configured to compensate for variations in alignment of the first component 310 and the second component 312 in the coupling 308. In some cases, the cylindrical surface 404 and the prismatic surface 502 may not be perfectly or perfectly aligned in a mating configuration due to, for example, frictional forces and / or tolerance variations between the components. The pin 412 can be configured to counteract and limit positional errors between the two components, thereby allowing the coupling 308 to maintain a stable and reliable connection between the first component 310 and the second component 312.

[0058] As discussed in detail below, the pin 412 can be configured to counter tolerance-based variations in the alignment of the first component 310 and the second component 312, thereby maintaining the two contact lines between the cylindrical surface 404 and the prismatic surface 502 at the coupling 308 despite these variations. Additionally, the distal end 412d of the pin 412 can provide an additional point of contact between the first component 310 and the second component 312 when the first component 310 and the second component 312 are not perfectly aligned. The additional point of contact can limit the degree to which the second component 312 can tilt relative to the first component 310. The reduced diameter portion 1004 of the pin 412 can compensate for tolerance variations in the alignment of the first component 310 and the second component 312 (i.e., tilt or other variations from an ideal relative position), thereby maintaining the first contact line 303 and the second contact line 305 at the coupling 308. Thus, the coupling 308 can provide precise mounting and orientation of a first object (e.g., the instrument adapter 302) associated with the first component 310 and a second object (e.g., the navigation array 304) associated with the second component 312.

[0059] FIG. 12 shows the first component 310 and the second component 312 perfectly aligned in the mating configuration of the coupling 308. In some embodiments, the perfect or ideal alignment can be evidenced from the back surface 432 of the first component 310 extending parallel to the back surface 520 of the second component 312. To help achieve perfect or parallel alignment between the first and second components 310, 312, it can be beneficial to have an extended contact area between the handle 418 and the first component 310. Such extended contact can provide good leverage for the handle 418 to achieve parallel alignment of the components 310, 312. For example, the diameter 1104 of the contact area between the planar surface 424 of the handle 418 and the back surface 432 of the first component 310 can extend across the width of the first component 310 (i.e., across the Y-axis of the first component 310). In some embodiments, the diameter 1104 can extend across the entire width or substantially the entire width of the back surface 432 of the first component 310 .

[0060] A clearance 1102 may extend between the pin 412 and the inner surface 517 of the second opening 516. In an ideal parallel alignment, the clearance 1102 may extend between the pin 412 and the inner surface 517 along the entire length of the second opening 516 (i.e., from the proximal end 516p to the distal end 516d of the second opening 516). The clearance 1102 may be small between the distal end 412d of the pin 412 and the inner surface 517 of the second opening 516, allowing the two components to slide against each other, but with negligible play between the components. As discussed in more detail below, the clearance 1102 may be widened along the reduced diameter portion 1004 of the pin 412. In some embodiments, such as the perfectly aligned configuration of FIG. 12, the screw 410 can successfully bring the first component 310 and the second component 312 into parallel alignment and limit movement in all six degrees of freedom without the pin 412 contacting the second component 312.

[0061] In contrast to the coupling shown in FIG. 12, in some cases, the alignment between the first component 310 and the second component 312 may be imperfect after the screw 410 engages the first opening 514 to secure the first and second components 310, 312. FIG. 13 shows the coupling 308 in one such example, where the first component 310 and the second component 312 are in a non-parallel alignment, for example, due to friction and / or tolerance variations between the two components. The scale of these figures is exaggerated, and the degree of tilt or misalignment between the components may be small, for example, small enough not to affect the ability of the threads formed in the screw 410 and the opening 514 to properly engage. As shown, the second component 312 may be tilted relative to the first component 310, such that the back surface 520 of the second component 312 extends at an oblique angle relative to the back surface 432 of the first component 310. For comparison, a parallel or perfectly aligned profile 1202 of the second component 312 is shown. An additional contact point 1204 may occur between the distal end 412d of the pin 412 and the second component 312. Thus, the tilt of the second component 312 may be limited to the point where the inner surface 517 of the second opening 516 contacts the distal end 412d of the pin 412. Thus, the contact point 1204 may constrain the orientation of the second component 312 relative to the first component 310 to a known and predictable configuration, providing stability to the coupling 308.

[0062] As described above, the clearance 1102 can extend between the reduced diameter portion 1004 of the pin 412 and the inner surface 517 of the second opening 516. The clearance 1102 can maintain two lines of contact 303, 305 between the second component 312 and the first component 310 despite the non-parallel alignment of the components. More specifically, the reduced diameter portion 1004 of the pin 412 aligns with a substantial portion of the opening 516 of the second component 312, including the proximal end 516p of the second opening 516, such that a portion of the sidewall of the second opening 516 can extend into the clearance 1102 in the non-parallel alignment without contacting the pin 412. Such a configuration allows the second component 312 to maintain contact with and move along the cylindrical surface 404 of the first component 310. For example, in the orientation shown in FIG. 13, the two contact lines 303, 305 can be maintained despite tilting of the second component 312. The prismatic surface 502 (i.e., side walls 508, 510) can translate along and maintain contact with the cylindrical surface 404. Thus, the reduced diameter portion 1004 of the pin 412, and the resulting clearance 1102, can add stability to the coupling 308 by allowing the two contact lines (e.g., the lines of contact 303, 305) to be maintained between the first component 310 and the second component 312 despite non-parallel or non-ideal alignment of the first and second components. Thus, even without parallel or ideal alignment, the coupling 308 in a fixed position can limit relative motion between the first component 310 and the second component 312 in all six degrees of freedom.

[0063] 13A, which shows a portion of FIG. 13 in region D in more detail, an alternative pin having a linear profile 1206 (i.e., an alternative / straight pin without a diameter reduction portion) may result in loss of contact between the first component 310 and the second component 312 in a non-parallel or non-ideal alignment. This is because the linear profile 1206 of the pin creates an area of ​​impingement 1208 between the pin and the second component 312 when the second component 312 is tilted relative to the first component 310. This may result in loss of at least one contact line between the first component 310 and the second component 312, adversely affecting the stability of the coupling 308. For example, a second contact point 1210 may occur between the linear profile 1206 of the alternative pin and the second component 312. This contact may cause the second component 312 to pivot away from the first component 310, resulting in loss of contact between the prismatic surface 502 and the cylindrical surface 404.

[0064] FIG. 14 illustrates the coupling 308 with the first component 310 seated within the second component 312. The screw 410 and pin 412 of the first component 310 may be received within the first and second openings 514, 516 of the second component 312, respectively. Although not visible, the cylindrical surface 404 of the first coupling component 310 may be seated within a recess formed by the prismatic surface 502 of the second coupling component 312. The distal surface 1002 of the pin 412 may be flush with the back surface 520 of the second component 312. The distal surface 421 of the screw 410 may be flush with the back surface 520 of the second component 312. In some embodiments, the distal surface 421 of the screw 410 being flush with the back surface 520 of the second component 312 may indicate that the screw 410 is not threadably engaged with the opening 516. Thus, the first component 310 and the second component 312 may be seated but not yet fully engaged or secured. In the seated configuration, relative motion between the first component 310 and the second component 312 may be limited, but not yet blocked, in one or more degrees of freedom, for example, by one or more of the contact between the cylindrical surface 404 and the prismatic surface 502, the pin 412 received in the second opening 516, and the screw 410 received in the first opening 514.

[0065] FIG. 15 illustrates the coupling 308 with the first component 310 mated or secured to the second component 312. The screw assembly 414 can be actuated to drive the screw 410 to mate the first component 310 with the second component 312. For example, a user can rotate the handle 418 in a first direction to drive the screw 410 within the first opening 514. In some embodiments, the distal end 420d of the screw 410 can extend beyond the back surface 520 of the second component 312. This can indicate that the screw 410 has been driven into threaded engagement with the first opening 514. In some embodiments, the entire unthreaded distal end 420d of the screw 410 can protrude from the first opening 514. This can serve as a visual indicator that the entire length of the threaded portion 422 of the screw 410 is engaged with the threaded inner surface 518 of the first opening 514. The distal surface 1002 of the pin 412 can remain flush with the underside 520 of the second component 312 when the first and second components 310, 312 are mated. As described above, in such a mated configuration, the screw 410 and pin 412 can block relative movement between the first and second components 310, 312 in all six degrees of freedom, such that there is negligible play between the components 310, 312. In some embodiments, the first and second components 310, 312 can have matching circumferences. The matching circumferences of the first and second components 310, 312 can create a continuous and smooth profile of the coupling 308, allowing for a quick visual confirmation that the components are properly aligned with one another.

[0066] To separate the first component 310 from the second component 312, the handle 418 can be driven or rotated in a second direction such that the screw 410 disengages from the first opening 514. More specifically, as the screw 410 rotates in the second direction, the threaded portion 422 of the screw 410 can move proximally through the opening 514, thereby allowing the proximal end 422p of the threaded portion 422 to exit the threaded surface 518 of the first opening 514. The first component 310 and the second component 312 can be completely separated when the distal end 422d of the threaded portion 422 exits the threaded surface 518 of the first opening 514. The first component 310 can then be moved away from the second component 312.

[0067] Generally, the first and second components 310, 312 may be fabricated from hard metals such as steel, titanium, etc. to reduce wear and allow for reuse of the instrument or object in which the components are formed or disposed. In other embodiments, certain polymers or other materials may also be suitable for use in forming the first and second components 310, 312.

[0068] The coupling 308 can be used to couple a first object associated with the first coupling component 310 to a second object associated with the second coupling component 312. The coupling 308 can be used with any of a variety of instruments or objects. For example, in some embodiments, the first object can be an instrument adaptor (e.g., instrument adaptor 302) configured to receive an instrument (e.g., instrument 306) and the second object can be a navigation array (e.g., navigation array 304). The position and orientation of the coupling components 310, 312 relative to the navigation array (e.g., navigation array 304) can be known such that the position and orientation of the instrument 306 attached to the array 304 by the coupling 308 (e.g., instrument 306 disposed in the instrument adaptor 302) can be determined from the position and orientation of the array 304. In an alternative embodiment, the first object can be an instrument such that the instrument can be directly coupled to the navigation array 304 via the coupling 308 without the need for the instrument adaptor 302. Although this specification refers to the instrument adapter 302 as a first object associated with the first coupling component 310 and the navigation array 304 as a second object associated with the second coupling component 312, in other embodiments, the instrument adapter 302 may be associated with the second coupling component 312, while the navigation array 304 may be associated with the first coupling component 310.

[0069] 16-21 show an embodiment of an instrument adaptor 302 in association with a first coupling component 310 and a navigation array 304 in association with a second coupling component 312. The first component 310 and the second component 312 can be identical to those of the first component and second component described in detail above with reference to Figures 3-15. Accordingly, a detailed description of their structure, operation, and use is omitted from the description of Figures 16-21 for the sake of brevity.

[0070] 16 and 17 show an embodiment of a navigation array 304 that can be used with the coupling 308 of the present disclosure. The navigation array 304 can include a frame 602 having a second component 312 formed thereon, e.g., integrally formed within the frame 602 or attached thereto. The frame 602 can include one or more prongs 604. Each prong 604 can have a mounting feature 606 that can receive a spherical fiducial or other marker for use with a navigation system. The mounting features 606 can be located at predetermined locations and orientations relative to each other and / or the frame 602. The mounting features 606 can be positioned such that, during use, a marker attached thereto can be located within the field of view of the navigation system and can be identified in images captured by the navigation system. By way of non-limiting example, the markers can include infrared reflectors, LEDs, and the like. The branches 604 and / or mounting features 606 may be positioned on the navigation array 304 having different positions and / or orientations than those of the illustrated navigation array 304. For example, the navigation array 304 shown in Figures 16 and 17 has three branches 604 with each branch having a single mounting feature 606, but the navigation array 304 may have a greater or lesser number of branches and / or mounting features. The navigation array 304 may include an inertial measurement unit (IMU), an accelerometer, a gyroscope, a magnetometer, other sensors, or a combination thereof. In some embodiments, the sensors may transmit position and / or orientation information to a navigation system, such as to a processing unit of the navigation system.

[0071] In the navigation array 304 shown in FIGS. 16 and 17, the coupling component (e.g., the first or second component described above) can be disposed on the underside or bottom of the array. For example, the second component 312 of the coupling 308 can be integrally formed with or attached to the bottom of the navigation array 304. Thus, in some embodiments, the navigation array 304 can function as a second object coupled to a first object by the coupling 308. FIG. 16 shows a front side of the navigation array 304 with the second component 312 formed on the bottom of the frame 602. In other embodiments, the second component 312 can be disposed in a different location relative to the navigation array 304. The prismatic surface 502 of the second component 312 can be formed on the front side of the navigation array 304. FIG. 17 shows a back side of the navigation array 304 with the second component 312 formed on the bottom of the frame 602. As can be seen, the identification pin 802 of the second coupling component 312 can be seen on the back side of the navigation array 304 .

[0072] 18-21 show various views of an embodiment of an instrument adaptor 302 in relation to a first coupling component 310. The instrument adaptor 302 can include an arm 320 having an instrument ring 322 at a first end thereof. Further details regarding the instrument ring 322 can be found in U.S. Patent Application Publication No. 2018 / 0344301 to Wehrli et al., entitled “Coupling Devices for Surgical Instruments and Related Methods,” filed May 31, 2017, which is incorporated by reference herein in its entirety. The instrument ring 322 can be configured to securely receive an instrument therein.

[0073] The first coupling component 310 can be attached to or formed on the second end of the arm 320, the second end being opposite the first end of the arm. FIG. 19 shows a side view of the instrument 302. As seen in FIG. 19, the first component 310 can be integrally formed with the adapter 302. In other embodiments, the first component 310 can be welded, threaded, glued, or otherwise attached to the instrument adapter 302. The screw 410 and the pin 412 can extend parallel to the longitudinal axis of the arm 320 of the instrument adapter 302. In other words, the screw 410, the pin 412, and the arm 320 can each extend parallel to and along the X-axis. In other embodiments, the instrument adapter 302 can have a different geometric configuration such that the instrument arm 320 can extend at an oblique angle to the screw 410 and the pin 412.

[0074] FIG. 20 illustrates the instrument adaptor 302 with the first component 310 in a perspective view, with the underside 432 of the first component 310 visible. FIG. 21 illustrates the instrument adaptor 302 with a front view of the first component 310 (i.e., a view showing the ZY plane, with the X-axis extending perpendicular to the page). As shown, the longitudinal axis (i.e., the Z-axis) of the first cylindrical surface 404 may be disposed perpendicular to the longitudinal axis of the adapter arm 320, which extends perpendicular to the page of FIG. 21. In other embodiments, the first component 310 may be disposed in a different positional relationship to the adapter arm 320, and more broadly, to the instrument adaptor 302 and / or an instrument disposed therein.

[0075] 22-26 illustrate an embodiment of a method using a coupling 308 to attach a first object to a second object, e.g., an instrument to a navigation array. Other than as set forth below, the steps of the described method may be performed in various orders and one or more steps may be omitted or added. Additionally, the instruments shown in the figures are merely examples, and alternative embodiments of the instruments, e.g., different first and / or second objects, etc., may be used in conjunction with the steps described below. A detailed description of each step sequence is omitted here for the sake of brevity.

[0076] In use, the first component 310 and the second component 312 can be coupled together to lock all degrees of freedom between the first object (e.g., the instrument adapter 302) and the second object (e.g., the navigation array 304) and to position the first object and the second object in a known, fixed relative position and orientation. As described in detail below, the first component 310 can be aligned with the second component 312. The first component 310 can then be brought into contact with the second component 312, such that the first component 310 is seated or positioned relative to the second component 312. The first component 310 and the second component 312 can then be mated or secured to complete the coupling of the first object to the second object.

[0077] 22 and 23, the first component 310 can be aligned with the second component 312. More specifically, the screw 410 extending from the first coupling component 310 can be aligned with the first opening 514 of the second component 312. The pin 412 extending from the first component 310 can be aligned with the second opening 516 of the second component 312. Proper orientation of the second object 304, and more specifically the second coupling component 312, can be visually confirmed, for example, by confirming that the identification pin 802 is visible on the bottom of the back surface 520 of the second component 312.

[0078] The first component 310 and the second component 312 may then be approximated such that the cylindrical surface 404 of the first coupling component 310 is positioned or seated against the prismatic surface 502 of the second coupling component 312. FIGS. 24 and 25 show the first component 310 seated against the second component 312. The screw 410 may be received in the first opening 514 and the pin 412 may be received in the second opening 516. As described in more detail above with reference to FIG. 14, in the seated configuration, the distal surface 1002 of the pin 412 and the distal surface 421 of the screw 410 may be flush with the back surface 520 of the second component 312. In some embodiments, this may demonstrate that the threaded portion 422 of the screw 410 is not fully threadably engaged with the first opening 514. 25, the screw assembly 414, and more specifically, the planar surface 424 of the handle 418, can be a predetermined distance away from the back surface 432 of the first component 310. A portion of the screw post 420 can extend proximally from the back surface 432 of the first component 310 between the handle 418 and the back surface. In some such embodiments, with the first component 310 seated against the second component 312, the planar surface 424 of the handle 418 can be parallel to, but removable from, the back surface 432 of the first component.

[0079] Once the first component 310 is positioned relative to the second component 312, a force can be applied to couple the first component 310 with the second component 312. In some embodiments, the handle 418 can be rotated in a first direction to drive the screw 410 in a first direction. Rotating the screw 410 in a first direction can move the screw distally through the first opening 514. The threaded portion 422 of the screw 410 can be threadingly engaged with the threaded inner surface 518 of the first opening 514. Driving the screw 410 can mate the first component 310 with the second component 312, thereby fixing the first component 310 relative to the second component 312. In some embodiments, the handle 418 can be rotated in a first direction until the planar surface 424 abuts the back surface 432 of the first component 310. More specifically, driving the screw 410 can tightly attract and lock the cylindrical surface 404 against the prismatic surface 502 of the second coupling component 312. As mentioned above, in some instances, fastening the first component 310 and the second component 312 can result in a perfectly aligned configuration of the first and second components 310, 312, while in other instances the first component 310 and the second component 312 can be fastened in imperfect alignment. Regardless, after fastening the coupling 308, the first component 310 and the second component 312 can be in a known position and orientation with negligible play or relative movement between them.

[0080] In some embodiments, the relative movement between the first component 310 and the second component 312 can be limited in all six degrees of freedom when the entire length of the threaded portion 422 (i.e., from the proximal end 422p of the threaded portion to the distal end 422d of the threaded portion) engages with corresponding threads on the threaded inner surface 518 of the first opening 514. The length of the threaded portion 422 of the screw 410 can be selected to achieve various functions during coupling. For example, the length can be selected such that the distal end 422d of the threaded portion 422 engages with the threads on the threaded inner surface 518 of the first opening 514 when the first coupling component 310 is seated within the second coupling component 312. In such a configuration, the engagement of the threads can provide a mechanical advantage to help draw the coupling components 310, 312 together during coupling and pull the coupling components apart during separation.

[0081] 26-30 show various views of the navigation array 304 coupled to the instrument adapter 302 with the coupling 308 in a fully mated or fixed position. The unthreaded distal end 420d of the screw 410 can extend beyond the back surface 520 of the second component 312. In some embodiments, this can serve as a visual confirmation that the first component 310 and the second component 312 are coupled such that relative movement between the two components is sufficiently blocked or limited. The planar surface 424 of the screw assembly 414 can abut the back surface 432 of the first component 310 to press the first component 310 against the second component 312.

[0082] As discussed in detail above, rotating the screw 410 can engage the threaded inner surface 518 of the first opening 514 of the second coupling 312 and can block relative motion between the first component 310 and the second component 312 along and about the X and Y axes. Relative rotation about the Z axis can also be blocked. To the extent that relative movement between the first component 310 and the second component 312 exists due to frictional forces once the screw 410 engages the threaded surface 518 of the first opening 514, the pin 412 received within the second opening 516 can further limit such relative motion along the Z axis, as discussed above.

[0083] Additionally, the first component 310 and the second component 312 can be coupled in a known position and / or orientation such that an associated first object (e.g., the instrument adapter 302) and an associated second object (e.g., the navigation array 304) are in a known position and / or orientation relative to one another. Thus, the navigation array 304 can be used in conjunction with the navigation system 307 to accurately and precisely position and navigate the instrument adapter 302 and / or the instrument 306 disposed therein. Although the description provided herein discusses the instrument adapter 302 in association with components of the coupling 308, the instrument can be directly associated with the components of the coupling 308 without the use of an instrument adapter. In other words, the first component 310 or the second component 312 of the coupling 308 can be attached to or otherwise disposed on the instrument. In this manner, the instrument can be directly coupled to the navigation array 304 (or other object) using the coupling 308.

[0084] Separating the first component 310 from the second component 312 can be accomplished by disengaging the screw 410 from the threaded inner surface 518 of the first opening 514. In some embodiments, this can include rotating the handle 418 in a second direction to rotate the screw 410 in a second direction. More specifically, as the screw 410 rotates in the second direction, the threaded portion 422 of the screw 410 can move proximally through the opening 514, which can cause a proximal end of the threaded portion 422 to exit the threaded surface 518 of the first opening 514. The first component 310 and the second component 312 can be completely separated when the distal end 422d of the threaded portion exits the threaded surface 518 of the first opening 514. The first component 310 can then be moved away from the second component 312. In some embodiments, separating the first component 310 and the second component 312 may include inserting an instrument through one or more of the openings 430 in the handle 418 of the screw assembly 414 and rotating the instrument, thereby increasing the torque applied to the handle 418.

[0085] 31-33 illustrate an alternative embodiment of coupling 1308. Except as noted below, the structure, operation, and use of this embodiment are similar or identical to those of coupling 308 described above, and therefore a detailed description of such structure, operation, and use is omitted here for the sake of brevity.

[0086] The coupling 1308 can include a first component 1310 associated with a first object (e.g., the instrument adapter 1302) and a second component 1312 associated with a second object (e.g., the navigation array 1304). With reference to FIG. 31 , the first coupling component 1310 can include a cylindrical surface 1404, a thread 1410, and a pin 1412. The thread 1410 can extend from a planar inlay 1416 on the cylindrical surface 1404. The planar inlay 1416 can be configured to span only an area of ​​the cylindrical surface surrounding the thread 1410 extending therefrom. Thus, the pin 1410 can extend from a convex portion of the cylindrical surface 1404.

[0087] 32 and 33 show a first object (e.g., an instrument adaptor 1302) coupled to a second object (e.g., a navigation array 1304) by a coupling 1308. Similar to the coupling 308 described above, the first component 1310 can be coupled to the second component 1312 to limit relative motion in all six degrees of freedom such that there is negligible play between the first component 1310 and the second component 1312. Thus, the instrument adaptor 1302 and the navigation array 1304 can be coupled in a known orientation by the coupling 1308. The instrument 1306 can be received within the instrument adaptor 1302 such that the position of the instrument 1306 can be accurately and precisely tracked using the navigation array 1304.

[0088] As is apparent from the foregoing, in at least some embodiments, the systems and methods disclosed herein can provide couplings having fully defined interfaces for mating an instrument and / or instrument adapter with a navigation array with minimal play and specific orientation for precise and accurate navigation of a surgical instrument.

[0089] Although particular embodiments have been described above, it should be understood that many modifications may be made within the spirit and scope of the described concepts. Accordingly, the present disclosure is not intended to be limited to the described embodiments, but rather to have full scope defined by the language of the following claims. The above embodiment describes a coupling 308 that couples a navigation array to an instrument or instrument adapter. While this is one contemplated use, the methods and devices of the present disclosure may be equally adapted for use with other objects. Thus, the devices and components described herein may be formed in a variety of sizes and materials suitable for use in a variety of applications.

[0090] Those skilled in the art will appreciate further features and advantages based on the above-described embodiments. Therefore, the present disclosure is not limited by what has been particularly shown and described. All publications and references cited herein are expressly incorporated herein by reference in their entirety.

[0091] [Embodiment] (1) A coupling for attaching a first object and a second object, comprising: a first coupling component associated with the first object, the first coupling component having a cylindrical surface with a screw and a pin extending therefrom; a second coupling component associated with the second object, the second coupling component having a prismatic surface, a first opening configured to receive the screw, and a second opening configured to receive the pin; A coupling, wherein the first coupling component and the second coupling component are adapted to mate with one another such that relative motion between the first coupling component and the second coupling component is limited in all six degrees of freedom. (2) The coupling of embodiment 1, wherein the pin includes a proximal end, a distal end, and a reduced diameter portion located proximal to the distal end of the pin. (3) The coupling of embodiment 2, wherein the distal end of the pin is torus shaped. (4) The coupling of embodiment 2, wherein the first coupling component and the second coupling component are configured such that at least a portion of the reduced diameter portion of the pin is disposed within the second opening of the second coupling component when the first coupling component and the second coupling component are mated. (5) The coupling of claim 4, wherein the pin is configured to limit relative movement between the first coupling component and the second coupling component along a longitudinal axis of the cylindrical surface.

[0092] (6) The coupling of embodiment 2, wherein the first component and the second component are configured such that when the pin of the first component is received within the second opening of the second component, a clearance exists between the pin and an inner surface of the second opening. (7) The coupling of embodiment 6, wherein the first component and the second component are configured such that the distal end of the pin can contact the inner surface of the second opening to limit movement of the second coupling component relative to the first coupling component. (8) The coupling of embodiment 1, wherein the first coupling component and the second coupling component are adapted to mate with each other such that a first contact line and a second contact line extend between the first coupling component and the second coupling component. (9) The coupling of embodiment 8, wherein the first contact line and the second contact line extend between the cylindrical surface of the first coupling component and the prismatic surface of the second coupling component. (10) The coupling of embodiment 8, wherein the first contact line and the second contact line extend along substantially the entire length of the cylindrical surface.

[0093] (11) The coupling of embodiment 10, wherein the first contact line and the second contact line are located on either side of a center line of the cylindrical surface. (12) The coupling of embodiment 8, wherein the prismatic surface includes a first end and a second end, a first sidewall and a second sidewall extending between the first end and the second end, and the first sidewall and the second sidewall extending at an angle relative to a backstop of the prismatic surface. (13) The coupling of embodiment 12, wherein the first contact line extends along the first sidewall of the prismatic surface and the second contact line extends along the second sidewall of the prismatic surface. (14) The coupling of embodiment 1, wherein the first object is a surgical instrument and the second object is a navigation array. (15) The coupling of embodiment 1, wherein the screw includes a post having a proximal end, a distal end, and a threaded portion located proximal to the distal end of the screw.

[0094] (16) The coupling of embodiment 1, wherein the first coupling component includes a back surface opposite the cylindrical surface, the back surface of the first coupling component being a flat planar surface. (17) The coupling of claim 16, wherein the first coupling component includes a throughbore configured to receive the screw such that the screw extends through the first coupling component perpendicular to the back side of the first coupling component. (18) A method of bonding a first object and a second object, comprising: aligning a first coupling component associated with the first object and a second coupling component associated with the second object, the first coupling component having a cylindrical surface with a screw and a pin extending therefrom and the second coupling component having a prismatic surface, a first opening, and a second opening; advancing the first coupling component relative to the second component such that the cylindrical surface is seated against the prismatic surface, the screw is received within the first opening, and the pin is received within the second opening; and fixing the first component and the second component such that relative movement between the first component and the second component is limited in six degrees of freedom. 19. The method of claim 18, further comprising limiting relative movement between the first component and the second component by contact between the pin and an inner surface of the second opening. (20) The method of embodiment 18, wherein securing the first component and the second component further comprises driving the screw within the first opening.

[0095] (21) The method of claim 20, wherein driving the screw prevents relative movement between the first component and the second component in at least five degrees of freedom. (22) The method of claim 20, wherein the pin limits relative movement between the first component and the second component after driving the screw to mate the first component and the second component. 23. The method of claim 22, wherein the pin contacts an inner surface of the second opening to limit relative movement between the first component and the second component. (24) The method of claim 22, wherein the limited relative movement between the first component and the second component is along a longitudinal axis of the cylindrical surface. (25) The method of claim 20, wherein driving the screw to mate the first component and the second component further comprises rotating the screw in a first direction such that a threaded portion of the screw fully engages a threaded inner surface of the first opening.

[0096] (26) The method of claim 25, wherein an unthreaded distal end of the screw extends beyond a back surface of the second component when the screw fully engages with the threaded inner surface of the first opening. (27) The method of claim 20, wherein driving the screw includes rotating a handle of a screw assembly in a first direction until a planar surface of the handle abuts a back surface of the first component. 28. The method of claim 18, wherein the first component and the second component contact one another along first and second contact lines extending between the cylindrical surface of the first component and the prismatic surface of the second component. (29) The method of embodiment 28, wherein the first contact line and the second contact line are located on opposite sides of a center line of the cylindrical surface.

Claims

1. 1. A coupling for attaching a first object and a second object, comprising: a first coupling component associated with the first object, the first coupling component having a convex surface from which a screw and a pin extend, the convex surface being shaped to correspond to a side of a cylinder cut by a plane parallel to a longitudinal axis of the cylinder; a second coupling component associated with the second object, the second coupling component having a prismatic surface, a first opening configured to receive the screw, and a second opening configured to receive the pin; the pin includes a proximal end, a distal end, and a reduced diameter portion located proximal to the distal end of the pin; the first coupling component and the second coupling component are configured such that when the pin of the first coupling component is received within the second opening of the second coupling component, a clearance exists between the pin and an inner surface of the second opening; the clearance is configured to be larger between the reduced diameter portion of the pin and the inner surface of the second opening than between the distal end of the pin and the inner surface of the second opening; a coupling, the first coupling component and the second coupling component adapted to mate with one another such that relative motion between the first coupling component and the second coupling component is limited in all six degrees of freedom.

2. The coupling of claim 1 , wherein the distal end of the pin is torus shaped.

3. 2. The coupling of claim 1, wherein the first coupling component and the second coupling component are configured such that at least a portion of the reduced diameter portion of the pin is disposed within the second opening of the second coupling component when the first coupling component and the second coupling component are mated.

4. The coupling of claim 3 , wherein the pin is configured to limit relative movement between the first coupling component and the second coupling component along a longitudinal axis of the convex surface.

5. 2. The coupling of claim 1, wherein the first coupling component and the second coupling component are configured such that the distal end of the pin can contact the inner surface of the second opening to limit movement of the second coupling component relative to the first coupling component.

6. 2. The coupling of claim 1, wherein the first coupling component and the second coupling component are adapted to mate with one another such that a first contact line and a second contact line extend between the first coupling component and the second coupling component.

7. 7. The coupling of claim 6, wherein the first contact line and the second contact line extend between the convex surface of the first coupling component and the prismatic surface of the second coupling component.

8. The coupling of claim 6 , wherein the first contact line and the second contact line extend along an entire length of the convex surface.

9. The coupling of claim 8 , wherein the first contact line and the second contact line are located on opposite sides of a center line of the convex surface.

10. 7. The coupling of claim 6, wherein the prismatic surface includes a first end and a second end, a first sidewall and a second sidewall extending between the first end and the second end, the first sidewall and the second sidewall extending at an angle relative to a backstop of the prismatic surface, the backstop being a planar surface bounded by the first end, the second end, the first sidewall, and the second sidewall.

11. The coupling of claim 10 , wherein the first contact line extends along the first sidewall of the prismatic face and the second contact line extends along the second sidewall of the prismatic face.

12. The coupling of claim 1 , wherein the first object is a surgical instrument and the second object is a navigation array.

13. The coupling of claim 1 , wherein the screw includes a post having a proximal end, a distal end, and a threaded portion located proximal to the distal end of the screw.

14. 2. The coupling of claim 1, wherein the first coupling component includes a back surface opposite the convex surface, the back surface of the first coupling component being a flat planar surface.

15. 15. The coupling of claim 14, wherein the first coupling component includes a through hole configured to receive the screw such that the screw extends through the first coupling component perpendicular to the back surface of the first coupling component.

Images