WO2025088551A1 - System and method for navigation - Google Patents

Abstract

Disclosed is a system for assisting in guiding and performing a procedure on a subject. The subject may be any appropriate subject such as inanimate object and/or an animate object.

Description

SYSTEM AND METHOD FOR NAVIGATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/593,864, filed 27 October 2023, the entire content of which is incorporated herein by reference.

[0002] This application includes subject matter related to the application 63/593,864 (Attorney Docket No. A0009694US01 / 5074A-0000297-US-PS1). The entire disclosure(s) of (each of) the above application(s) is (are) incorporated herein by reference.

FIELD

[0001] The subject disclosure is related generally to a tracking and navigation system, and particularly to tracking using an electromagnetic field and related sensor.

BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] An instrument can be navigated relative to a subject for performing various procedures. For example, the subject can include a patient on which a surgical procedure is being performed. During a surgical procedure, an instrument can be tracked in a physical space which may also be referred to as an object or subject space. In various embodiments, the subject space can be a patient space defined by a patient. The location of the instrument that is tracked can be displayed on a display device relative to an image of the patient. [0004] The position of the patient can be determined with a tracking system. Generally, a patient is registered to the image, via tracking an instrument relative to the patient to generate a translation map between the subject or object space (e.g., patient space) and the image space. This often requires a user, such as a surgeon, to identify one or more points in the subject space and correlating, often identical points, in the image space.

[0005] After registration, the position of the instrument can be appropriately displayed on the display device while tracking the instrument. The position of the instrument relative to the subject can be displayed as a graphical representation, sometimes referred to as an icon on the display device.

SUMMARY

[0006] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0007] According to various embodiments, an imaging system may be used to acquire image data of a subject. The imaging system may include an ultrasound imaging system that includes an ultrasound (US) probe that generally includes an ultrasound transducer to emit and receive ultrasound frequencies. It is understood, however, that the imaging system may include separate components that emit and receive ultrasound frequencies.

[0008] A tracking system, such as a tracking system that emits an electromagnetic field, may be used to track one or more tracking devices. The tracking devices may be positioned on instruments (which may include procedure instruments, imagers, or other members) and tracked in a physical space also referred to as a patient space. The position of the tracking device and an instrument with which it is associated (e.g., attached to) may be displayed in an image representing the subject. For example, the determined position may be superimposed on a portion of the image.

[0009] An electromagnetic (EM) field may be emitted by an emitter or transmitter and may be sensed by an electromagnetic sensing device of the tracking device. According to various embodiments, the electromagnetic sensing device may include one or more coils of a conductive material or may include other sensors including but not limited to Hall effect, flux gate, magneto-resistive, tunnel junction, optical, microelectromechanical systems (MEMS), magneto-optical, sensors or may include combinations thereof. Various other materials, such as conductive, magnetic, or conductive and magnetic materials, may interfere with a field being sent by the sensor. The interference with the field that is sensed by the sensor, however, may be quantified and analyzed to determine the position or orientation or subsets of such degrees of freedom of a portion that is interfering with the field.

[0010] A navigation system may be used to register or after an image is registered to a navigation space. Thus a pose of a tracked portion or member may be displayed relative to an image. Also, systems may be used where a patient is not registered to an image but where an imaging device is tracked so that a pose of the acquired image data and related image are tracked.

[0011] According to various embodiments, a sensor may be positioned relative to an object that is an interfering object. The interfering object may be moved relative to the sensor and where related distortion may be measured in the sensed field. A metric may be used to determine the amount of distortion. Metrics may include geometry determination and/or phase shift determinations. The position of the interfering object may be characterized by the metric being used to measure the distortion. The value of the metric may change based upon the position of the distorting or interfering object. Therefore, even if a tracking device is not attached directly to an interfering object, a position of the interfering objection may be characterized and determined relative to the tracking device including an EM field sensor in a volume. Therefore, the position of the interfering object may be determined relative to an instrument portion including the tracking device.

[0012] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0013] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0014] Fig. 1 is diagrammatic view illustrating an overview of a robotic system and a navigation system, according to various embodiments;

[0015] Fig. 2 is a schematic illustration of an instrument having at least a first portion and a second portion, according to various embodiments; [0016] Fig. 3 is a detailed schematic view of the instrument to Fig. 2 positioned in a portion of a subject;

[0017] Fig. 4 is a schematic illustration of an instrument having two portions moveable in one degree of freedom in a first configuration;

[0018] Fig. 5A is a schematic illustration of the instrument of Fig. 4 having two portions in a second configuration;

[0019] Fig. 5B is a schematic illustration of a tracking device and a sensed configuration of a tracking device, according to various embodiments;

[0020] Fig. 6A is a schematic illustration of the instrument of Fig. 4 having two portions in a third configuration, according to various embodiments;

[0021] Fig. 6B is a schematic illustration of a tracking device and a sensed tracking device, according to various embodiments;

[0022] Fig. 7 is a schematic illustration of an instrument having at least first and second portions moveable in two degrees of freedom in a first configuration, according to various embodiments;

[0023] Figs. 8A and 8B are schematic illustrations of the instrument of Fig. 7 in a second configuration;

[0024] Figs. 9A and 9B are schematic illustrations of the instrument of Fig. 7 in a third configuration;

[0025] Fig. 10 is a schematic illustration of an instrument in a first configuration having at least three degrees of freedom of movement of a first portion relative to a second portion, according to various embodiments; [0026] Fig. 11 is a schematic illustration of the instrument of Fig. 10 in a second configuration;

[0027] Fig. 12 includes a schematic illustration of various instruments in multiple configurations; and

[0028] Fig. 13 is a flowchart illustrating a process, according to various embodiments.

[0029] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0030] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0031] The subject disclosure is directed to an exemplary embodiment of a surgical procedure on a subject, such as a human patient. It is understood, however, that the system and methods described herein are merely exemplary and not intended to limit the scope of the claims included herein. In various embodiments, it is understood, that the systems and methods may be incorporated into and/or used on non-animate objects. The systems may be used to, for example, to register coordinate systems between two systems for use on manufacturing systems, maintenance systems, and the like. For example, automotive assembly may use one or more robotic systems including individual coordinate systems that may be registered together for coordinated or concerted actions. Accordingly, the exemplary illustration of a surgical procedure herein is not intended to limit the scope of the appended claims.

[0032] Discussed herein, according to various embodiments, is a tracking system that may be used to track a selected tracking device. The tracking system may operate, according to various embodiments, by emitting an electromagnetic (EM) field from a localizer, also referred to as an EM localizer. The EM field may be emitted from one or more coils that may be oriented relative to an origin point. The coils may emit the field. The field may be a largely magnetic field. The field may be constant or varying in time. A tracking device may include one or more coils of conductive material that operate as sensors to sense the field. The field may generate a voltage or current within the coil of the tracking device. A determination of a position and orientation (also referred to collectively as a “pose”) of the tracking device may be made based on a determination of the induced voltage or current from the field. It is further understood that an EM, or any appropriate tracking system, may operate by emitting a signal (e.g., EM fields) from the tracking device and receiving signals at the localizer.

[0033] Various materials are conductive or conductive and magnetic, such as conductive polymers, metal or metal alloys, or other materials. Objects or items may be formed with these materials. If an item formed with these materials is also in or near the field generated by the EM localizer, a current may be formed or induced or magnetization coerced in the object. In this instance, the object may be referred to as an interfering or target object. When a current is induced or a magnetization coerced in the interfering object, a field may also be produced. A field produced due to the induced current or coerced magnetization in the interfering object may also be referred to as an interfering field. These interfering fields may alter the field sensed by the tracking device such that it is not always sensing only the EM field generated by the EM localizer. The tracking device may sense both the EM field from the localizer and the EM field that is the interfering field. According to various theories, the sensed field may be a combination of both and/or the EM field from the EM localizer that is altered by the interfering field.

[0034] Various portions may be tracked relative to the subject. For example, a tracking system may be incorporated into a navigation system that includes one or more instruments that may be tracked relative to the subject. The navigation system may include one or more tracking systems that track various portions, such as tracking devices, associated with instruments. The tracking system may include a localizer that is configured to, alone or in combination with a processor, determine the pose of a tracking device in a navigation system coordinate system. Determination of the navigation system coordinate system may include those described at various references including U.S. Pat. No. 8,737,708; U.S. Pat. No. 9,737,235; U.S. Pat. No. 8,503,745; and U.S. Pat. No. 8,175,681 ; all incorporated herein by reference. In particular, a localizer may be able to track an object within a volume relative to the subject. The navigation volume, in which a device may be tracked may include or be referred to as the navigation coordinate system or navigation space. A determination or correlation between two coordinate systems may allow for or also be referred to as a registration between two coordinate systems. [0035] Furthermore, images may be acquired of selected portions of a subject. The images may be displayed for viewing by a user, such as a surgeon. The images may have superimposed on a portion of the image can include a graphical representation of a tracked portion or member, such as an instrument. The images may have a coordinate system and define an image space. According to various embodiments, the graphical representation may be superimposed on the image at an appropriate position due to registration of an image space (also referred to as an image coordinate system) to a subject space. A method to register a subject space defined by a subject to an image space may include those disclosed in U.S. Pat. Nos. U.S. Pat. No. 8,737,708; U.S. Pat. No. 9,737,235; U.S. Pat. No. 8,503,745; and U.S. Pat. No. 8,175,681 ; all incorporated herein by reference. In various embodiments, however, the imaging device may be tracked so its images may be tracked in a navigation space. In such a system a display of tracked instruments relative to tracked images without a tracked or registered patient may occur. Also, displaying tracked instruments and images relative to a tracked and registered patient.

[0036] The tracking of an instrument during a procedure, such as a surgical or operative procedure, allows for navigation of a procedure. When image data is used to define an image space it can be correlated or registered to a physical space defined by a subject, such as a patient as discussed herein. According to various embodiments, therefore, the patient defines a patient space in which an instrument can be tracked and navigated. The image space defined by the image data can be registered to the patient space defined by the patient. The registration can occur with the use of fiducials that can be identified in the image data and in the patient space.

[0037] Fig. 1 is a diagrammatic view illustrating an overview of a procedure room or arena. In various embodiments, the procedure room may include a surgical suite in which may be placed a robotic system 20 and a navigation system 26 that can be used for various procedures. The robotic system 20 may include a MazorX™ robotic guidance system, sold by Medtronic, Inc. The robotic system 20 may be used to assist in guiding a selected instrument, such as drills, screws, etc. relative to a subject 30. In addition or alternatively, the robotic system 20 may hold and/or move an imaging system, such as an ultrasound (US) probe 33 or 33’. The robotic system 20 may include a mount 34 that fixes a portion, such as a robotic base 38, relative to the subject 30. The robotic system 20 may include one or more arms 40 that are moveable or pivotable relative to the subject 30, such as including an end effector 44. The robotic arm 40 may be controlled by a selected robotic control module, which may be included with the navigation system or processor, as discussed herein, or a separate robotic control module 45. The robotic control module 45 may include one or more processors or memory that may communicate, execute instructions, or store instructions for operation of the robotic arm 40. The end effector may be any appropriate portion, such as a tube, guide, or passage member. Affixed to and/or in place of the end effector may be the imaging system that may be the US probe 33. The end effector 44 may be moved relative to the base 38 with one or more motors. The position of the end effector 44 may be known or determined relative to the base 38 with one or more encoders at one or more joints, such as a wrist joint 48 and/or an elbow joint 52 of the robotic system 20. One or more portions of the robotic system 20 may be formed of conductive materials.

[0038] The navigation system 26 can be used to track the location of one or more tracking devices and/or determine and/or illustrate a pose thereof. Tracking devices may include a robot tracking device 54, a subject tracking device 58, an imaging system tracking device 62, an imaging system or second imaging system tracking device 81 , and/or an instrument or tool tracking device 66. A tool or moveable member 68 may be any appropriate tool such as a drill, forceps, catheter, or other tool operated by a user 72. The tool 68 may also be and/or an implant, such as a spinal implant or orthopedic implant. Further, the tool 68 may include one or more moveable portions, such as deployable portions. For example, a heart valve replacement and related inserter tool that may insert the instrument 68 or selected portion, such as an implant, into a heart 127 of the subject 30 and/or any other appropriate portion of any appropriate subject. It should further be noted that the navigation system 26 may be used to navigate any type of instrument, implant, or delivery system, including: guide wires, arthroscopic systems, orthopedic implants, spinal implants, deep brain stimulation (DBS) probes, etc. Moreover, the instruments may be used to navigate or map any region of the body. The navigation system 26 and the various instruments may be used in any appropriate procedure, such as one that is generally minimally invasive or an open procedure. [0039] An additional or alternative, imaging system 80 may be used to acquire pre-, intra-, or post-operative or real-time image data of a subject, such as the subject 30. It will be understood, however, that any appropriate subject can be imaged and any appropriate procedure may be performed relative to the subject. In the example shown, the imaging system 80 comprises an O-arm® imaging device sold by Medtronic Navigation, Inc. having a place of business in Colorado, USA. The imaging system 80 may have a generally annular gantry housing 82 in which an image capturing portion is moveably placed and/or enclosed. The imaging system 80 can include those disclosed in U.S. Pat. Nos. 7,188,998; 7,108,421 ; 7,106,825; 7,001 ,045; and 6,940,941 ; all of which are incorporated herein by reference, or any appropriate portions thereof. It is further appreciated that the imaging system 80 may include in addition or alternatively a fluoroscopic C-arm. Other exemplary imaging devices may include fluoroscopes such as biplane fluoroscopic systems, ceiling mounted fluoroscopic systems, cath-lab fluoroscopic systems, fixed C-arm fluoroscopic systems, isocentric C-arm fluoroscopic systems, 3D fluoroscopic systems, etc. Other appropriate imaging devices can also include MRI, CT, ultrasound, etc.

[0040] The position of the imaging system 33, 80, and/or portions therein such as the image capturing portion, can be precisely known relative to any other portion of the imaging device 33, 80. The imaging device 33, 80, according to various embodiments, can know and/or recall precise coordinates relative to a fixed or selected coordinate system. For example, the robotic system 20 may know or determine its position and position the US probe 33 at a selected pose. The image data acquired with one or more ultrasound arrays of the US probe 33 may be registered in the navigation system such as disclosed in the U.S. Patent No. 7,085,400 and U.S. Patent No. 9,138,204, both incorporated herein by reference. Similarly, the imaging system 80 may also position the imaging portions at a selected pose. This can allow the imaging system 80 to know its position relative to the patient 30 or other references. In addition, as discussed herein, the precise knowledge of the position of the image capturing portion can be used in conjunction with a tracking system to determine the position of the image capturing portion and the image data relative to the tracked subject, such as the patient 30. In other words, the imaging system tracking device 62, 81 may be used and/or operable to determine a pose of the imaging system 33, 80 at a selected time such as during image data acquisition. The position of the imaging system, according to various embodiments, may be used for registration of an image space or coordinate system to a patient space or coordinate space. The robotic system may also be registered to one or more spaces or coordinate systems such as by the system and method as disclosed in U.S. Pat. No. 11 ,135,025, incorporated herein by reference.

[0041] Herein, reference to the imaging system 33 may refer to any appropriate imaging system, unless stated otherwise. Thus, the US probe 33 as the imaging system is merely exemplary regarding the subject disclosure. As one skilled in the art will understand, generally the US probe 33 may emit a US wave in a plane and receive an echo relative to any portions engaged by the wave. The received echo at the US probe 33 or other appropriate received may be used to generate image data and may be used to generate an US image also referred to as a sonogram.

[0042] The imaging device 80 can be tracked with the tracking device 62. Also, the tracking device 81 can be associated directly with the US probe 33. The US probe 33 may, therefore, be directly tracked with a navigation system 26 as discussed herein. In addition or alternatively, the US probe 33 may be positioned and tracked with the robotic system 20. Regardless, image data defining an image space acquired of the patient 30 can, according to various embodiments, be registered (e.g., manually, inherently, or automatically) relative to an object space. The object space can be the space defined by a patient 30 in the navigation system 26.

[0043] The patient 30 can also be tracked as the patient moves with a patient tracking device, DRF, or tracker 58. Alternatively, or in addition thereto, the patient 30 may be fixed within navigation space defined by the navigation system 26 to allow for and/or maintain registration such as to the image space of the image 108. As discussed further herein, registration of the image space to the patient space or subject space allows for navigation of the instrument 68 with the image data. When navigating the instrument 68, a position of the instrument 68 can be illustrated relative to image data acquired of the patient 30 on a display device 84 such as with a graphical representation 68i, 68i’. Alternatively, the patient 30 may not be tracked or fixed and the system may track the instrument 68 relative to imaging device 33 and their associated images. An additional and/or alternative display device 84’ may also be present to display an image. Various tracking systems, such as one including an optical localizer 88 or an electromagnetic (EM) localizer 92 can be used to track the instrument 68.

[0044] More than one tracking system can be used to track the instrument 68 or other portion, such as the US probe 33 with the tracking device 81 in the navigation system 26. According to various embodiments, these can include an electromagnetic tracking (EM) system having the EM localizer 94 and/or an optical tracking system having the optical localizer 88. Either or both of the tracking systems can be used to track selected tracking devices, as discussed herein. It will be understood, unless discussed otherwise, that a tracking device can be a portion trackable with a selected tracking system. A tracking device need not refer to the entire member or structure to which the tracking device is affixed or associated.

[0045] The position of the patient 30 relative to the imaging device 33 can be determined by the navigation system 26. The position of the imaging system 33 may be determined, as discussed herein. The patient 30 can be tracked with the dynamic reference frame 58, as discussed further herein. Accordingly, the position of the patient 30 relative to the imaging device 33 can be determined.

[0046] Image data acquired from the imaging system 33, or any appropriate imaging system, can be acquired at and/or forwarded from an image device controller 96, that may include a processor module, to a navigation computer and/or processor module (also referred to as a processor) 102 that can be a part of a controller or work station 98 having the display 84 and a user interface 106. Further, a memory system or module 103, of any appropriate type, may be accessed by the processor 102. It will also be understood that the image data is not necessarily first retained in the controller 96, but may also be directly transmitted to the work station 98. The work station 98 can provide facilities for displaying the image data as an image 108 on the display 84, saving, digitally manipulating, or printing a hard copy image of the received image data. The user interface 106, which may be a keyboard, mouse, touch pen, touch screen or other suitable device, allows the user 72 to provide inputs to control the imaging device 80, 33, via the image device controller 96, or adjust the display settings of the display 84. The work station 98 may also direct the image device controller 96 to adjust the image capturing portion of the imaging device 80 to obtain various two- dimensional images along different planes in order to generate representative two- dimensional and three-dimensional image data.

[0047] With continuing reference to FIG. 1 , the navigation system 26 can further include the tracking system including either or both of the electromagnetic (EM) localizer 94 and/or the optical localizer 88. The tracking systems may include a controller and interface portion 110. The controller 110 can be connected to the processor portion 102, which can include a processor included within a computer. The EM tracking system may include the STEALTHSTATION® AXIEM™ Navigation System, sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colorado; or can be the EM tracking system described in U.S. Patent Application Serial No. 10/941 ,782, filed Sept. 15, 2004, and entitled "METHOD AND APPARATUS FOR SURGICAL NAVIGATION"; U.S. Patent No. 5,913,820, entitled “Position Location System,” issued June 22, 1999; and U.S. Patent No. 5,592,939, entitled “Method and System for Navigating a Catheter Probe,” issued January 14, 1997; all of which are herein incorporated by reference. It will be understood that the navigation system 26 may also be or include any appropriate tracking system, including a STEALTHSTATION® TREON®, S7™ , S8™ tracking systems having an optical localizer, that may be used as the optical localizer 88, and sold by Medtronic Navigation, Inc. of Colorado. Other tracking systems include an acoustic, radiation, radar, etc. The tracking systems can be used according to generally known or described techniques in the above incorporated references. Details will not be included herein except when to clarify selected operation of the subject disclosure.

[0048] Wired or physical connections can interconnect the tracking systems, imaging device 80, etc. Alternatively, various portions, such as the instrument 68 may employ a wireless communications channel, such as that disclosed in U.S. Patent No. 6,474,341 , entitled “Surgical Communication Power System,” issued November s, 2002, herein incorporated by reference, as opposed to being coupled directly to the controller 110. Also, the tracking devices 62, 66, 54 can generate a field and/or signal that is sensed by the localizer(s) 88, 94.

[0049] Various portions of the navigation system 26, such as the instrument 68, and others as will be described in detail below, can be equipped with at least one, and generally multiple, of the tracking devices 66. The instrument can also include more than one type or modality of tracking device 66, such as an EM tracking device and/or an optical tracking device. The instrument 68 can include a graspable or manipulable portion at a proximal end and the tracking devices may be fixed near the manipulable portion of the instrument 68.

[0050] Additional representative or alternative localization and tracking system is set forth in U.S. Patent No. 5,983,126, entitled “Catheter Location System and Method,” issued November 9, 1999, which is hereby incorporated by reference. The navigation system 26 may be a hybrid system that includes components from various tracking systems.

[0051] According to various embodiments, the navigation system 26 can be used to track any appropriate portion such as the US probe 33 and/or the instrument 68 relative to each other or the patient 30. The instrument 68 can be tracked with the tracking system, as discussed above. Image data of the patient 30, or an appropriate subject, can be used to assist the user 72 in guiding the instrument 68. The image data may or may not be registered to the patient 30. For example, as discussed herein, the US probe 33 is tracked and generates the image data. Thus, as discussed above, the image data need not be registered to the subject to display a pose of the tracked instrument 68 relative to the image data generator with the tracked US probe 33. The image data defines the image space that is registered to the patient space defined by the patient 30. The registration can be performed as discussed herein, automatically, manually, or combinations thereof. The registration can include the process and the final transformation (including a translation and rotation) map. Generally, registration includes determining points in the image data and the subject space and determining a transformation map therebetween. Once done, the image space are registered to the subject space, or any two or more coordinate spaces.

[0052] Generally, registration also allows a transformation map to be generated of a tracked physical pose of the instrument 68 relative to the image space of the image data. The transformation map allows the tracked position of the instrument 68 to be displayed on the display device 84 relative to the image data 108. The graphical representation 68i, also referred to as an icon, can be used to illustrate the location of the instrument 68 relative to the image data 108.

[0053] With continuing reference to Fig. 1 , a subject registration system or method can use the tracking device 58. The tracking device 58 may include portions or members 120 that may be trackable, but may also act as or be operable as a fiducial assembly. The fiducial assembly 120 can include a clamp or other fixation portion 124 and the imageable fiducial body 120. It is understood, however, that the members 120 may be separate from the tracking device 58. The fixation portion 124 can be provided to fix any appropriate portion, such as a portion of the anatomy. As illustrated in Fig. 1 , the fiducial assembly 120 can be interconnected with a portion of a spine 126 such as a spinous process 130. The fixation portion 124 can be interconnected with a spinous process 130 in any appropriate manner. For example, a pin or a screw can be driven into the spinous process 130. Further, the tracking device 58 may be operable to track with one or more tracking systems or modalities, such as EM tracking system or optical tracking system. [0054] As illustrated in Fig. 1 , the imaging device 33 may include the US probe 33 that may be positioned relative to the subject 30, such as by the robotic system 20 and/or the surgeon 72. In various embodiments, the surgeon 72 may operate the robotic arm 20 and/or hold the US probe 33 separate therefrom. As discussed herein, therefore, the robotic system 20 may move the US probe 33 to a selected position relative to the subject 30. According to various embodiments, the imaging system may be positioned relative to the subject in any appropriate manner.

[0055] Determination of a position of an object, such as a tracking device may be performed in any appropriate manner. Further, positions of various portions relative other tracking device may also be determined. According to various embodiments, a pose of an interfering object (which may be conductive) may be determined relative to a tracking device within an EM navigation coordinate system particularly when an EM field is emitted and distorted relative to a interfering item that may generate or emit fields in light of induced currents or coerced magnetizations in the item.

[0056] The instrument 68 may be any appropriate instrument, and as discussed herein may include an instrument that may be used in various procedures. According to various embodiments, for example, the instrument 68 may include an inserter or guided catheter 200, as illustrated in Figs. 2-6B. The instrument 200 may be used in addition to and/or as the instrument 68. Therefore, discussion of the instrument 200 may include all the features identified above relative to the instrument 68, such as tracking and illustration of a pose of the instrument 68 relative to the selected image data, such as with the graphical representation 68i.

[0057] The instrument 200 may include various portions that allow the instrument 200 to be used relative to the subject 30. For example, the instrument 200 may include a handle 202 that may include various portions, such as guiding or directing portions 204 that may cause a catheter or extension portion 208 of the instrument 200 to bend or move relative to an axis 210 of the handle 202. Further, the instrument 200 may include one or more extendable portions, such as a capsule 212 that may move, such as axially, relative to a distal tip 214 of the extension portion 208. The capsule portion 212 may extend or be moved along an axis 216 that may be extend or be defined by the distal portion 214 of the catheter portion 208.

[0058] Therefore, the catheter portion 208 may be moved within the subject 30 for a selected procedure. The directing portions 204 on the handle 202 may be used to bend or move the catheter portion 208 to direct an angle or turn of the distal end 214.

[0059] The tracking device 66 may be positioned at or near the distal tip 214 of the catheter portion 208. According to various embodiments, the tracking device 66 may be connected (e.g., fixed) to the catheter portion 208, such as at the distal tip 214. Accordingly, the tracking device 66 may be used to track a pose of at least the distal tip 214 of the catheter portion 208. As discussed above, however, as the capsule 212 moves away from the distal tip 214, a specific pose of the capsule may not be directly known due to the tracked pose of the tracking device 66. As discussed herein, the capsule 212 may be proximate, including in contact with, the distal tip 214. Thus, the tracked pose of the tracking device 66 may be used to know directly the pose of the capsule 212 when proximate the distal tip 214. The capsule 212, however, as discussed herein, may move away from and/or be remote from the distal tip 214. Thus, the tracked pose of the tracking device may not be used to directly know the pose of the capsule 212.

[0060] To determine a pose of the capsule 212, especially when it is remote from the distal tip 214, a metric may be measured at or with the tracking device 66. The capsule 212 may include at least a portion and/or be entirely formed of an interfering material (which may be a conductive material) The interfering material of the capsule 212 may have currents induced to therein due to the EM field generated by the EM localizer 94. The induced currents in the capsule 212, including in the conductive material thereof, may generate fields that are emitted from the capsule 212. The fields emitted from the capsule 212 may affect the tracking device 66 and/or the fields sensed by the tracking device 66. The fields emitted by the induced currents in the capsule 212 may be referred to as induced fields. Thus, as discussed further herein, a pose of the capsule 212 may be determined relative to the subject 30 at least based upon the induced fields sensed at the tracking device 66 and the tracked pose of the tracking device 66.

[0061] Turing reference to Fig. 3, the instrument 200, including the catheter portion 208 may be positioned within a selected portion of the subject 30, such as a heart 127. The instrument 200 may be used to position selected implant, such as a valve replacement 224. The valve assembly 224 may be any appropriate valve assembly and/or any appropriate implant, that may be positioned within an appropriate subject, such as the patient 30. In various embodiments, for example, the Intrepid ™ transcatheter mitral valve replacement system, a valve replacement under investigation by Medtronic, Inc., having a place of business in Minneapolis, Minnesota. The instrument 200 may be a catheter use to provide or move the implant into a selected location, such as at or near a mitral valve 226 of the subject within the heart 127. The instrument 200, including the catheter portion 208, may include a first portion 230 and a second portion 234. The two portions 230, 234 may move relative to one another, as illustrated in Fig. 3. The tracking device 66 may be positioned near the distal tip 214 of the second portion 234. Therefore, the tracking device 66 may be used to track a pose of the distal tip 214 of the instrument 200. When in a proximate position (e.g., a fully collapsed or retracted position), as illustrated in Fig. 2, the pose of the tracking device 66 may be used to determine or understand the position of the capsule 212 as the capsule 212 is at a fixed position relative to the distal end 214. The capsule 212, however, may be moved remote from the distal tip 214 such as relative to a piston 238. The piston 238 may seal relative to an interior wall 239 of the capsule 212. A fluid may be moved or forced through a tube (also referred to as a movement member) 242 that may extend from the distal end 214. The tube 242 may be generally rigid such that it extends along an axis 244 that is generally perpendicular to a face plane 246 of the distal end 214 of the catheter portion 208. The capsule 212 may be sealed at a distal end such that as fluid is forced past the piston 238 the capsule with will move along the axis 244. Thus, the capsule 212 may move axially relative to the distal end 214, such as generally in one degree to freedom along the axis 244.

[0062] As illustrated in Fig. 3, the capsule 212 may be affected by fields emitted by the EM localizer 94. Currents may be induced in the capsule 212 (such as in the conductive portions thereof) and one or more fields, such as represented by field lines 250 may be generated due to the induced currents in the capsule 212. The induced field 250 may affect or be sensed by the tracking device 66.

[0063] With reference to Fig. 4, the instrument 200 may be provided in a first configuration (e.g., a proximate configuration), including when the capsule 212 is at or near the mitral valve 226 as illustrated in Fig. 3. The capsule 212 may encapsulate the implant 224, as illustrated in Fig. 4. The implant 224 may be positioned within the capsule 212 to be released or delivered due to movement of the capsule 212, as illustrated in Fig. 3, and discussed further herein. The implant 224 may only fully expand and/or be positioned when the capsule 212 is fully removed from the implant 224 and at a selected remote position relative to the distal tip 214. Therefore, determining our understanding the position of the capsule relative to the implant 224 may be selected. The position that the capsule 212 is relative to the distal end 214 when the implant 224 is fully released from the capsule 212 may be predetermined, such as based upon the size of the implant 224, anatomy, or the like.

[0064] As illustrated in Fig. 4, the capsule 212 may include a dimension that is a linear dimension 250. The dimension 250 may be predetermined or known. An initial position of a distal end or point 254 of the capsule 212 may be known relative to the tracking device 66. As discussed above, the piston 238 may be positioned within the capsule 212. In various embodiments, the piston 238 may move relative to the distal end 214 of the instrument 200 due pressure of a fluid moving through the tube 242 and past the piston 238 to move the capsule 212 relative to the distal end 214. In various embodiments, the piston 238 stays stationary with respect to 214 and the fluid pushes the capsule 212 out along linear dimension 250 relative to the piston 238 the end 214 and the tracker 66. The capsule 212 is configured and able to move relative to the tracking device 66 which is fixed to the insertion portion 208 of the instrument 200. In the initial or collapsed configuration, as illustrated in Fig. 4, the dimension 250 of the capsule 212 may also relate to and/or be the dimension of the distal point 254 of the capsule 212 from the tracking device 66.

[0065] With continued reference to Fig. 4, and additional reference to Fig. 5, the capsule 212 may move relative to the distal end 214. The capsule 212 may move due to the piston 238 and the fluid passing through the tube 242 generally in the direction of arrow 254. A volume between the piston 238 and a distal end 256 of the capsule may be filled with the liquid to move the capsule 212 away from the distal end 214. The dimension of the distal end 256 from the distal end 214 may, therefore, change. As illustrated in Fig. 5, the implant 224 may be partially released or exposed from the capsule 212. A dimension 258 may be defined between the distal end 214 and/or the tracking device 66 and the distal end 256.

[0066] As discussed above, the EM localizer 94 may emit a field. The emitted field may interact with the capsule 212 that may be formed of or include a conductive material. The conductive material may be a portion of at least a wall 262. Induced in the wall 262 may be a current, also referred to as an induced or eddy current 264. The Eddy currents may also flow around the diameter of the capsule 212. The eddy current 264 may generate a field 268 that may also be referred to as an induced field. The field may be in addition to and/or distort the field generated by the EM localizer 94. Therefore, the induced field 268 may also be sensed by the localizer 66, as schematically illustrated in Fig. 5. The field 268 generated by the induce eddy current 264 may be referred to as an interfering or induced field herein to distinguish it from the field generated by the EM localizer 94. It is understood, however, by one skilled in the art, that the field sensed by the tracking device 66 may include fields that are interacting (e.g., additive or subtracting) such that the tracking device 66 senses a field that is due to a combination of various factors. Nevertheless, the induced field from the capsule 212 may be known based upon the field generated with the EM localizer 94 and the material and geometry of the capsule 212. The induced eddy current 264 may, therefore, be known and/or predetermined such that the interfering field 268 may also be known that is sensed by the tracking device 66.

[0067] The point 254 that may move with the capsule 212 may move relative to a distal end point to 270 that may be at a distal end of the piston 238. In the initial position, such as when the capsule 212 is contacting the extension portion 208, the distal point 270 of the piston may be substantially coextensive with the distal point 254 of the capsule 212. Nevertheless, as the capsule 212 moves, the distal point 254 moves away from the distal point 270 of the piston 238. The induced current 264 in the capsule 212 that generates the field 268 may, therefore, affect the tracking device 66. The distance 258 may be determined based upon a measurement of a metric at the tracking device 66. The metric may be any appropriate metric based upon the selected tracking system. For example, a phase shift of the received signal may be determined, a change in sensed or determined geometry of the tracking device may be determined, or other appropriate metrics may be used. A phase shift may be a shift or change in phase of the sensed EM signal of the signal that localizer 94 sensed by the tracking device 66. A change in the geometry may refer to a change in the sensed geometry of the tracking portions of the tracking device 66.

[0068] For example, with reference to Fig. 5B, the tracking device may include a plurality of coils that may sense a field by having a current induced therein. The coils may be positioned in a selected geometry, such as a first coil 280, a second coil 284, and a third coil 288. The coils may be substantially equilaterally placed relative to one another, for example, in a plane but may also be positioned in any three-dimensional configuration relative to one another. For example, each may be wrapped around different (e.g., orthogonal axes) but have a common center point. Therefore, the tracking device 66 is merely exemplary. Nevertheless, a dimension, such as an equilateral dimension may be known or predetermined between each of the coils such as a first dimension 290 between the first coil and the second coil, a second dimension 292 between the first coil and the third coil, and a third dimension 294 between the second coil and the third coil. This geometry may be known and predetermined and saved in the navigation system, such as memory module thereof.

[0069] When the tracking device 66 senses a field, the geometry of the tracking device 66 may be determined. In a known field, the geometry may be measured to be substantially equilateral, as illustrated in the tracking device 66. However, under a selected or known distorted field or with a known secondary field, a measured or determined tracking device 66Z1 may be determined. The tracking device that is measured 66Z1 may have each of the coils measured, such as a first measured coil 280', as a second measured coil 284', and a third measured coil 288'. However, the measured or determined distances between each of the coils may not be the equilateral distances but may be other distances such as a first measured distance 290' between the first measured coil 280’ and the second measured coil 284’, a second measured distance 292' between the first measured coil 280’ and the third measured coil 288’, and a third measured distance 294' between the second measured coil 284’ and the third measured coil 288’. The different distances may be the metric that is measured.

[0070] The three distances or orientation of the coil may be measured and compared to a predetermined measurement that is based upon a predetermined distance of the capsule 212. The predetermined measurements of the metric and the related predetermined post of the capsule 212 (such as a distance from the tracking device 66) may be saved in a memory module. Therefore, the geometry of the measured tracking device 66Z1 , as illustrated in Fig. 5B for example, may relate to the distance 258 as illustrated in Fig. 5A. Therefore, if a measured geometry of the tracking device 66Z1 is measured during a procedure, the distance 258 may be determined, such as via the lookup table. The determined distance 258 may be based upon a lookup table of a predetermined distance 258 and the predetermined measured geometry 66Z1. Therefore, the displayed icon or graphical representation of the device 68i may illustrate the dimension 258 of the capsule 212.

[0071] Turning reference to Fig. 6A and Fig. 6B, the capsule 212 may continue to move in the direction of the arrow 253 relative to the piston 238. Again, the terminal or distal point 254 of the capsule may move relative to the distal point 270 of the piston 238. As illustrated in Fig. 6A, the implant 224 may be completely released from the capsule 212. The capsule 212 may therefore be at a second position such that the distal end 256 is a distance 300 from the distal end 214 of the catheter portion 208. Again, the tracking device 66 may be positioned or fixed to the distal end 214. As discussed above, however, the capsule 212 may still be affected by emitted fields from the EM localizer 94 such that the current 264 is induced therein which further generates the induced field 268. The induced field 268 may still affect the tracking device 66. However, the induced field 268 may have a different strength, orientation, or the like relative to the tracking device 66 when the distance 300 of the capsule 212 exists. Therefore, the sensed field may be a slightly changed field 268' as illustrated in Fig. 6A. Again, the tracking device 66 may have a known and fixed geometry of various tracking coils or portions 280- 288, as illustrated in Fig. 6B. Due to the slightly changed field 268', however, a sensed or measured tracking device 66Z2 may be measured. Therein, the measured coils 280", 284" and 288" may have the metric defined relative to them measured. Distances between these may include a first distance 290", a second distance 292", and a third distance 294". These three distances 290"-294" may also be predetermined based upon the distance 300 of the capsule 212 in the field emitted by the EM localizer 94. Therefore, again, when the measured tracking device 66Z2 is measured, a lookup table may be used to determine a dimension or the position of the capsule 212, which may be determined to have the dimension 300 relative to the distal end 214. The determined position of the capsule 212 may then be illustrated on the display device 84, such as with a graphical representation 68i.

[0072] In light of the above, therefore, the tracking device 66 and the sensed field therewith may be used to determine a pose of a portion of the instrument 68 that is not directly tracked with a tracking device affixed thereto, such as the tracking device 66. The portion that moves relative to the tracking device 66 may affect the field emitted by the EM localizer 94 and/or generate a secondary field, such as the field 268, that may be sensed by the tracking device 66. A metric that is measured by the navigation system may be used to determine a pose of the movable portion, such as the capsule 212, relative to the tracking device 66. The metric may be used to determine a precise pose of the portion that has moved relative to the tracking device 66, particularly when the movement is limited in various dimensions. For example, the capsule 212 generally moves only along the axis in the direction of the arrow 253. Therefore, the dimension of the capsule 212 relative to the distal end 214 may be determined based upon the measured metrics of the tracking device 66. In various embodiments, one measured and determined geometry metric may be used to determine one distance or one degree of freedom. According to various embodiments, various techniques may be used to measure distorted fields and determine non-distorted fields, such as those disclosed in U.S. Pat. No. 11 ,439,317, U.S. Pat. No. 11 ,571 ,261 , U.S. Pat. App. No. 2021/0330390, or U.S. Pat. App. Pub. No. 2021/0330391 , all incorporated herein by reference, and determine both distorted and non-distorted geometries to then determine a constant tracker position and orientation as well as a capsule extension.

[0073] In various embodiments, an average tracked position and orientation of the coils may remain largely constant from configuration 66 to 66z1 to 66z2. As an example, the triangle plane and centroid may remain largely constant from configuration 66 to 66z1 to 66z2 so that the determined position and orientation of tracker 66 remains largely constant as capsule 212 moves away from tracker 66.

[0074] By knowing the dimension of the capsule 212, a determination may be made that the implant 224 is completely released from the instrument 68. It is understood that any appropriate implant may be determined to be released and the position of various portions may be displayed on the display device.

[0075] Further, the illustrations of Figs. 5A and 6A may be displayed as graphical representations on the display device 84 to illustrate the determined pose or navigated pose of various portions such as the capsule 212, the extension portion 208, the implant 224, or the like. It is also understood that the representations may relate to a real or patient space pose of the various portions, such as illustrated in Fig. 3. Accordingly, the details and schematic illustrations in Figs. 5A and 6A are exemplary illustrations of real or determined poses of the instrument 68 and portions thereof.

[0076] The capsule 212 may be formed of a selected conductive material. For example, various steel or steel alloys may be used. Other conductive materials may also be provided in the capsule 212. Further, capsule 212 may not be made entirely of a conductive material, but may have conductive portions formed therewith. For example, the capsule 212 may be formed of a polymer material having one or more conductive members or features included therewith, such as metallic sheets or the like. Nevertheless, the conductive portions may have currents induced therein, such as the current 264, that may then emit or generate the field 268. This may allow a determination of a pose of the capsule or movable portion that does not have a tracking device relative to a tracking device, such as the tracking device 66.

[0077] With continuing reference to Fig. 1 and the discussion above, and with additional reference to Fig. 7, an instrument 320 is illustrated. The instrument 320 may be similar to the instrument 68 as discussed above save for the portions discussed herein. Accordingly, discussion of the instrument 320 may relate to and/or be incorporated into a discussion of the instrument 68 above and may include features similar thereto. For example, the instrument 320 may include an extendable or catheter member 324 and a relatively movable member or capsule 326. The capsule 326 may be similar to the capsule 220 discussed above. The instrument 320 may further include the tracking device 66 dispositioned near a distal end 328 of the extendable portion 324. The capsule 326 may be formed or include conductive materials, such as that discussed above.

[0078] With additional reference to Fig. 8A and Fig. 8B, the capsule 326 may be moved away from the distal end 328 of the catheter member 324. The tracking device 66, however, may be maintained at or near the distal end 328. The catheter member 324 may extend along an axis 332. The axis 332 may be defined or known relative to the tracking device 66. The axis 332 may be referred to or understood as long axis of the extendable instrument portion 324 and/or the tracking device 66. The capsule 326 may be moved away from the distal end 328 by an extending or pushing portion or driving portion 334. According to various embodiments, the extending or driving portion 334 may move or push the capsule 326 away from the distal end 328 and/or the driving portion 334 may be a tube to apply or move a fluid to move the capsule 326 away from a distal end or end of the driving member 334 as discussed above. Regardless, the capsule 326 may be moved a distance 338 from the distal end 328. The distance 338 may be measured from a distal end 340 of the capsule 336 from the distal end 328 of the extendable portion 324. The distance 338 may be measured along the axis 332.

[0079] In addition, the capsule 326 may be moved away from the axis 332. As illustrated in Fig. 8A, for example, the capsule 326 may define or have an axis 344 and the capsule axis 344 may extend at an angle 348 from the axis 332. Therefore, the capsule 326 may move along an arc 352 relative to the central axis 332. The arc 352 may be defined by rotation of the capsule 326 relative to the central axis 332, such as the direction of arrow 356. Therefore, a pose of the capsule 326 may include at least two degrees of freedom, including the distance 338 and the angle 380 which may allow the capsule 326 to be moved in the arc at a pose relative to the tracking device 66. Accordingly, in this example angle 348 may be considered fixed so that two degrees of freedom that may be determined may include the extension distance 338 and rotation angle 380 around arc 352. This may allow the tracking device 66 to be tracked directly by the navigation system, the pose of the capsule 326 may not be directly known by tracking the tracking device 66.

[0080] However, as discussed above, a current may be induced in the capsule or a portion of the capsule 326. A representation of the current includes the current line or circle 360. The current may be induced in a conductive portion of the capsule 326, similar to the discussion above. The induced current may generate a field 364 that is emitted or generated by the induced current 360. The field 364 may be sensed by the tracking device 66, as discussed above. A metric may be measured at the tracking device or determined at the tracking device 66 to assist in determining a pose of the capsule 326 relative to the tracking device 66. Again, the metric may be any appropriate metric, such as those discussed above including a geometric change measurement metric. Other metrics may include phase shift or shifts, a solve residual, or other appropriate metrics. Nevertheless, a pose of the capsule 326 may be determined by measuring the metric at the tracking device 66. In other words, in this example two or more measured and determined metric components or metrics may be used to determine various measurements, such as in one instance one distance and one rotation or in another instance two degree of freedoms.

[0081] Again, the pose of the capsule 326 may be predetermined based upon the metric. The determined pose may include both the distance 338 and the angle 380. Further, the angle 380 may be defined relative to the tracking device 66 as the capsule 326 rotates around the axis 332 but the tracking device 66 remains in a single position.

[0082] For example, with reference to Fig. 9, the capsule 326 may be rotated relative to the axis 332 in the direction of the arrow 368. Therefore, the axis 344 of the capsule 326 may form an angle 384 around the axis 332. While the angle 370 may be similar or identical to the angle 348, the arc position relative to the tracking device 66 may be different, as illustrated in Figs. 9A and 9B relative to the arc position illustrated in Figs. 8A and 8B. Therefore, the arc position of the capsule 326 may again be determined due to the inducement of the current 360 and the field 364' generated by the induced current 360. Therefore, the pose of the capsule 326 may be determined in at least two degrees of freedom including the arc position and a distance from the tracking device 66. Again, the determined pose of the capsule 326 may be determined in the patient space and/or illustrated with a graphical representation and image such as the supply device 84. Therefore, the determined pose of an untracked or indirectly tracked portion may be determined in at least two degrees of freedom relative to a tracking device.

[0083] The pose of the capsule 326, when extended from the distal end 328, may include the distance 338 in both the arcuate positions illustrated in Figs. 8A and 9A. However, as illustrated in Figs. 8A and 8B, the arcuate position along the circle 352 may be an arc position 380 that is illustrated to be above the tracking device 66. However, in the arc position illustrated in Figs. 9A and 9B, the capsule 326 may be in an arc position 384 that is illustrated to be below the tracking device 66. The relative arc positions 380, 384 may be understood to be right, left, up or down of the tracking device 66 but may be predetermined or measured relative to the tracking device 66. Therefore, the respective fields 364, 364' may be based upon both the distance 338 and the arc position. Further the distance 338 may vary, similar to the various positions of the capsule 212 discussed above.

[0084] Turning reference to Figs. 10 and 11 , with continuing reference to Figs. 7-9B, an instrument 390 is illustrated. The instrument 390 may include portions similar to those discussed above, such as an extendable portion 394 that may be moved in the selected region, the tracking device 66, that may extend along or define an axis 398. Further, the instrument 390 may include a movable or capsule member 402. The capsule 402 may extend along an axis 404. The capsule 402 may have a distal end or portion 408. The distal end 408 may be moved relative to a distal end 412 of the extendable portion 394. The axis 404 may define an angle 418 relative to the axis 398. As discussed above, the distal end 408 may also be moved a distance away from the distal end 412 of the extendable member 394.

[0085] The capsule 402 may have a current 422 induced therein that may generate a field 426 that may be sensed by the tracking device 66. Similar to that discussed above, the sensing at the tracking device 66 of the field 426 may be used to determine a distance 430 and an arc length or position relative to the tracking device 66. Further, according to various embodiments, the push or moving member 434 may be flexible and allow the capsule 402 to be positioned at different angles relative to the axis 398. Therefore, the angle 418 may also be specifically determined. Thus, the navigation system may determine three degrees of freedom of a pose of the capsule 402 relative to the tracking device 66. Thus, the capsule 402 may be positioned relative to the distal end 412 and the three degrees of freedom including the distance 430, the angle 418, and an arc length or position, such as the arc 352, as discussed above.

[0086] Accordingly, with reference to Fig. 11 , an angle 438 may be different than the angle 418 between the axis 404 and the axis 398 of the instrument 390. The distance and arc displacement may be the same, while the angle may be different. Thus, the capsule 402 may also be at a different angle when the moving or forcing member 434 is flexible.

[0087] Thus, according to various embodiments, the instrument 390 may have three degrees of freedom of movement of the capsule 402 relative to the tracking device 66 that may be determined relative to the tracking device 66. In other words, three or more measured and determined metric components or metrics may be determined to determine three degrees of freedom (e.g., angles or dimensions). Again, the instrument 390 may include features similar to the instrument 68 discussed above and the schematic illustrations of Figs. 10 and 11 may represent a physical or patient space position of the various portions of the instrument 390 and/or a graphical representation thereof. Thus, the pose or position of the capsule 402 may be determined relative to the tracking device.

[0088] The tracking device may be tracked with the navigation system 20 for a representation and determination of the pose of the capsule 402. Again, the pose of the capsule 402 may be determined due to the field 426, 426' that is generated based upon the induced current 422. The metric may be measured or determined at the tracking device 66 based upon the field 426, 426' that is generated by the capsule portion 402. This allows a determination of a pose of the capsule portion 402 relative to the tracking device 66 while the capsule portion 402 is not directly tracked by a tracking device connected directly thereto.

[0089] Turning reference to Fig. 12, the instrument 68, as discussed above, may be provided in a plurality of configurations. For example, the instrument may include the steerable catheter assembly 200 discussed above, the steerable catheter 220 discussed above and/or the steerable catheter 390 discussed above. In each of the various exemplary embodiments, the instrument 68 may be provided with at least a first portion having a tracking device affixed thereto and a second portion without a tracking device affixed thereto that moves relative to the first portion that includes the tracking device. According to various embodiments, the instrument may be inserted substantially within the patient, such as a steerable catheter into the heart 127 in various embodiments, however, an instrument need not be inserted into an internal organ of the subject entirely. For example, various suture, stapling, fixation systems may be used. For example, a Signia™ or Endo GIA™ stapling system, sold by Medtronic, Inc., may be used. [0090] According to various embodiments, a stapler may have various configurations or portions, as exemplary illustrated in Fig. 12. An instrument 460 is illustrated according to various embodiments in Fig. 12. The staplers 460 may include a first stapler 464 that includes a handle or grasping region 468 and a movable or stapling region 472. The moving region 472 may generally be movable and/or have a portion that is movable relative to the tracking device 66 that may be connected to a shaft 474 that extends from the handle. The stapler assembly 464 may include a first portion 478 that is substantially immovable relative to the shaft 474 and generally stays aligned with an axis 480 of the shaft. Therefore, a distal tip point 484, which may also be referred to as a primary point, may generally be known at a fixed pose relative to the tracking device 66. However, a second portion or jaw 486 may move at a pivot point 488 relative to the first jaw portion 478. Therefore, an angle 490 may be formed between the first jaw 478 and the second jaw 486. The angle 490 may vary as the instrument 464 is manipulated during use.

[0091] A measured or metric point 494 may be determined relative to the tracking device 66 and/or any other portion of the instrument 464 in a manner similar to that discussed above. For example, the EM localizer 94 may generate a field that causes an induced current in at least the second jaw portion 486. As the jaw portion moves to form the angle 490, such that the point 494 moves along an arc 496, an induced current 498 may generate a field 500 similar to that discussed above. The field 500 may be sensed by the tracking device 66. Therefore, a metric measured at the tracking device 66 may include the metrics as discussed above. The pose of the metric or measured point 494 may then be determined based upon the measurement of the metric at the tracking device 66. This may allow for a determination of the pose of at least the second jaw 486 relative to a portion of the instrument 464, such as the first jaw 478.

[0092] The tracking of the metric or measured point 494 may allow for determination of a pose of both distal portions of the instrument 464. It may further assist in ensuring that appropriate tissues are captured for stapling or manipulating with the instrument 464. Further, it may be used to confirm that a selected distance or pose is achieved between various portions of the instrument 464, such as ensuring that the second jaw 486 moves close enough to the first jaw 478 for stapling selected tissues. Again, a pose of the various jaws of the instrument 464 may allow for confirming or performing a procedure.

[0093] To assist in a procedure, such as confirmation of the procedure various outputs may be made. The pose may be illustrated on the display device 84. Further, other outputs may be provided, such as a confirmation signal, including a visual or audio signal, that a selected gap has been closed or that an angle or arc length has been traversed to confirm a specific operation of the instrument 464.

[0094] According to various embodiments, the instrument 68 may include an instrument that may be manipulated at a handle with a distal portion that includes movable portions that may move relative to the tracking device 66. The various movable portions may include a single movable portion or multiple movable portions. Further, the movable portions may be fixed in position relative to a main shaft and/or may be movable relative thereto. Nevertheless, the metric measured at the tracking device 66 may be used to determine a pose of movable portions relative to the tracking device 66 even if a tracking device is not connected directly to the moveable portion. Therefore, a pose of movable portions may be navigated during a procedure and a pose may be output, such as a display on the display device 84 with a graphical representation thereof.

[0095] With continued reference to Fig. 12, therefore, various other instruments may be provided similar to the instrument 464. For example, an instrument 520 may also include a handle portion 524 similar to the handle portion 468, a shaft portion 526 similar to the shaft portion 474 with a tracking device 66 connected thereto. The shaft may extend along an axis 528 that is substantially immovable relative to the handle 524. However, the instrument 520 may include two jaws or movable members including a first movable member 532 and a second movable member 534. The two movable members may move relative to a pivot portion 536 of the instrument 520.

[0096] As illustrated in Fig. 12, each of the jaws 532, 524 may move along respective arcs or arc lengths relative to the axis 528. The first jaw 532 may move along or be variably positioned along an arc 540 and the second jaw 534 may be moved along a second arc 544. A primary point 548 may be known or predetermined relative to the tracking device 66. As the shaft 526 is substantially immobile relative to the tracking device 66, the primary point 548 may be generally known and fixed relative to the tracking device 66. However, one or more metric or measured points 552 and 554 measured relative to the two movable jaws 532, 534, respectively, may be determined based upon a measurement of a metric at or with the tracking device 66. The two jaws 532, 534 may have currents induced therein that may generate fields that may be measured at the tracking device 66, similar to the discussion above. Therefore, the pose of the two jaws 532, 534 may be determined based upon the measurement of a metric at the tracking device 66. Thus, again, the pose of the two jaws 532, 534 may be known or determined based upon the measurement of a metric and allow for navigation during a procedure.

[0097] With continuing reference to Fig. 12, an instrument 460 may include an instrument 570. The instrument 570 may again include a handle 574 similar to the handle 524 discussed above, a shaft 576 similar to the shaft 526 discussed above and a tracking device 66 connected to the shaft 576. The shaft 576 may extend along an axis 578 relative to the tracking device 66, as discussed above. The instrument 570 may include two jaws or members including a first jaw 580 and a second jaw 584. Each of the jaws may move relative to each other and/or the shaft at a pivot point or joint 588. Therefore, for example, the first jaw 580 may move along an arc 590 relative to the axis 578 and the second jaw 584 may move along an arc 594 relative to the axis 578. Each of the jaws 580, 584 may be move independently and separately relative to the axis 578 along with respective arcs 590, 594. In various configurations, however, the two jaws may move together along either the arcs, such as the arc 594' relative to the axis 578. Therefore, a determination of a pose of both of the jaws separately or together may be determined based on the measurement of the metric. [0098] Again, a primary point or initial point 600 may be determined as a fixed point relative to the tracking device 66 as the tracking device is connected to the shaft 576 that is generally inflexible or immovable. The pose of the jaws 580, 584, either together or independently, may be determined based upon a metric or measured point 604, 606 for the respective jaws 580, 584 or a unitary metric point 610 for the two jaws together 580, 584. The pose of the jaws 580, 584 at the respective metric points 604, 606, 610 may again be determined based upon a field generated by an induced current in the jaws that may be sensed at the tracking device 66. Again, the EM localizer 94 may generate a field that induces the current in thejaw portions 580, 584. Therefore, a pose of the jaws that changes relative to the tracking device 66 may be measured due to a field that is generated by an induced current in the jaws 580, 584.

[0099] According to various embodiments of the instruments as discussed above, a field may be generated by a portion that does not have tracking device connected directly thereto. Therefore, a portion, such as a jaw or a capsule, may move relative to a tracking device while the tracking device remains stationary in a subject or a navigation space. The moving portion may have a current induced to therein which generates a field. The field generated by the induced current in the moving portion may effect a measurement of a metric at the tracking device 66, according to various embodiments as discussed above. The effect at the tracking device 66 may be a metric or may include a metric that is measured. The measurement of the metric may be used to determine a pose of the moving portion at an appropriate time, such as during movement or after it has stopped. The determined pose of the moving portion may be based upon a predetermined pose and measurement of the metric that may be predetermined and stored in a lookup table or other appropriate memory system. Therefore, when a metric is measured, the metric value may be compared to the lookup table to determine the pose of the moving portion. Thus, the moving portion need not have a tracking device connected directly thereto to allow for a determination of a pose of the moving portion.

[00100] In various embodiments, the lookup table may include a selected number of specific poses (e.g., locations and orientations) of the movable portion relative to the tracking device 66. Each of the poses may correlate to, as saved in the a lookup table, a measurement of the metric. Thus, a measured value of the metric is correlated to one pose of the moveable portion. However, a measured value of the metric may not match identically to only one predetermined measured value of the metric. For example, the saved measurement value may include 1 , 2, and other values but the measured value may be 1 .6. Therefore, the system, such as the processor module executing instructions, may interpolate between at least between two values to determine a likely pose of the movable portion during navigation. For example, the system may determine that the moveable portion is between the poses related to the measured values or 1 and 2, but 60% closer to the pose for the measured value of 2.

[00101] According to various embodiments, a discrete lookup table of single or multiple metric parameters to single or multiple pose degrees of freedom may be saved. An interpolation between or amongst them using single or multivariate, linear or nonlinear, global or local, functions or splines or other interpolations may occur.

[00102] According to various embodiments, a model (e.g., of the above interpolations) may be generated. The model may describe the relationship or relationships between or amongst single or multiple metric parameters to single or multiple pose degrees of freedom.

[00103] Turning reference to Fig. 13, a method or process 700 is illustrated. The method 700 may be used to assist in performing a procedure to determine a pose of an instrument or at least a portion of an instrument that does not have a tracking device connected or affixed thereto. As discussed above, the tracking device may be affixed to at least a portion of an instrument and a second portion may move relative to the tracking device. The second portion may be a capsule, movable jaw, or any appropriate portion. The second or moveable portion may be navigated when no tracking device is connected directly thereto. Accordingly, discussion herein of a capsule is merely exemplary of a movable portion may have a current induced therein that generates a field.

[00104] The method or process 700 may start in start block 704. The method 700 may then include loading an implant into an instrument as an optional step. As discussed above, the instrument may include an implant delivery system and therefore loading an implant block 708 may be optional step. The method 700 may then include positioning the capsule at a first position relative to the tracking device in block 710. The positioning of the capsule at a first position may include connecting or holding the capsule at a first position relative to the instrument, such as the instrument 200. This may include a time when the capsule is being moved or prior to the capsule being moved to a selected implant position. The instrument may then be moved to a selected position in block 712. Moving the instrument to a selected position may include moving the instrument, such as the instrument 200, relative to the heart 127. The moving of the instrument may include moving all of the instrument, including the capsule at the first position relative to the tracking device.

[00105] At a selected point, the capsule may be moved relative to the tracking device, such as to a second position in block 714. Moving the capsule relative to the tracking device may include moving or pumping a fluid relative to the capsule as discussed above. This may allow the capsule to move relative to another portion of the instrument, such as a portion including the tracking device, as discussed above. The movement of the capsule may include moving the capsule from a proximate position near the tracking device to a remote position away from the tracking device. Thus, the capsule may include at least two poses relative to the tracking devices. The moveable portion, however, may include a plurality of remote poses as discussed above.

[00106] The process 700 may include portions that are generally inclusive of moving the instrument for various purposes, such as moving an instrument with an implant relative to a human subject. The process 700, therefore, may include at least a subroutine or portion 720 that includes the steps or elements as discussed above including optionally loading the implant in block 708, positioning the capsule at the first position relative to the tracking device in block 710, moving the instrument to a selected position in block 712, and moving a capsule to a second position relative to the tracking device in block 714. The navigation system, including the tracking device 66, may be used to track the instrument substantially directly during the instrument having the capsule in the first position relative to the tracking device. Moving the capsule to the (or at least one) second position relative to the tracking device may allow the navigation system to measure a metric, as discussed above. Therefore, the navigation system may execute various instructions to determine a pose of the capsule once it is moved from the first position as discussed above, and according to at least the portions of a subroutine 730. In the subroutine 730, a signal may be received from the tracking device based upon a sensing with the tracking device in block 734. A determination of a measurement of the metric may be made in block 736. The metric may be any appropriate metric, such as those discussed above. The determination of the metric may be based upon measuring the or receiving the sensed measurement and/or performing a calculation based upon this sensed measurement. For example, as discussed above, a field may be measured with the tracking device 66. The metric may be based upon the measurement of the field such as the field that is based upon or generated due to an induced current in the capsule.

[00107] Based upon the determined metric, a recalled pose of the capsule may be made in block 740. Again, as discussed above, the pose of the capsule may be predetermined based upon various measured or determined metrics. Therefore, the pose may be recalled once the metric is determined in block 736. The recall may include a use of a lookup table that compares the determined measurement of the metric with predetermined metric measurements and corelated poses.

[00108] Once the pose is recalled in block 740, it may be output in block 744. Again, the output pose may be recalled and/or determined. For example, the pose may be based upon an interpolation between at least two predetermined measurements of the metric and related poses. The output may include various outputs, such as a visual indication of a pose of the capsule, such as a graphical representation on the display device 84. Other outputs may include an audio or visual confirmation of a predetermined pose, such as a proximity of the jaws of an instrument.

[00109] Regardless, after the output of the pose based upon the measured metric in block 736, a determination of whether the capsule has moved may be made in block 748. The determination of whether the capsule has moved in block 748 may be according to various processes. For example, the user may input that the capsule has moved such as with an appropriate input. Further, the system may sense that the capsule has moved such as with a change in the measured metric or signal received from the tracking device, such as with a continuous or constant measurement. Regardless, if a determination of the capsule has been moved is made a YES path 750 may be followed to receive a signal from the sensing of the tracking device in block 734. Therefore, the process 730 may iterate to allow for a continuous update of a pose of the capsule. The update may be substantially real time and may allow for a continuous iteration until the user has provided an input that the capsule has stopped moving or is not moving. [00110] If a determination of the capsule has not moved, a NO path 752 may be followed. The NO path 752 may include an optional confirmation of capsule pose relative to a plan in block 758. For example, as discussed above, the capsule may be used to assist in positioning the implant 224. Therefore, the user may confirm that the capsule is at a selected pose, such as a pre-planned and/or determined pose, relative to the tracking device prior to ending a procedure. In other words, the navigation of the moveable portion (e.g., the capsule) may allow for confirmation of a selected portion of a procedure (e.g., implant placement) without further analysis, such as image data capture. Nevertheless, the process 700 may end in END block 760 after determination that the capsule is no longer going to be moved by following path 752. However, if the capsule is not in a confirmed posed, the process may again iterate to receive additional signals in block 734, if selected.

[00111] Therefore the system, as discussed above, may be used to track a portion of an instrument that is not directly connected to a tracking device. The system may execute instructions similar or including instructions for forming at least a part of the method 700, such as the position determining sub-routine 730. The navigation system may include a processor that executes instructions to perform the steps as discussed above to allow for a determination, such as is substantially automatic determination, of the pose of a portion of the instrument, such as the capsule. Therefore, the system discussed above may allow for a substantially automatic determination by executing an instruction similar to those discussed above. [00112] According to various embodiments, the ultrasound probe may emit or transmit ultrasound waves in a selected pattern or plane. The plane may be a shape as is understood by one skilled in the art. The plane is generally able to acquire data in a field of view to generate images, also referred to as sonograms when images are generated based on ultrasound data.

[00113] Examples

[00114] 1 . A system to navigate an instrument for a procedure relative to a subject, comprising: an instrument having a first instrument portion and a second instrument portion having an interfering portion; a tracking device connected to the first instrument portion, wherein the tracking device includes at least one field sensor and wherein the second instrument portion is moveable relative to the tracking device; wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; a navigation processor configured to execute instructions to: receive afield signal from the tracking device based at least in part on sensing the interfering field at the at least one field sensor, determine a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluate the determined pose relative to a planned final pose, and output the evaluation of the determined pose relative to the planned final pose.

[00115] 2. The system of Claim 1 , further comprising: an electromagnetic (EM) localizer configured to generate a localizer field; wherein the localizer field causes an interfering field in the interfering portion of the second instrument portion. [00116] 3. The system of Claim 2, wherein the second instrument portion is configured to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00117] 4. The system of Claim 2, wherein the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device; wherein a measurement of a metric with the tracking device is determined from the interfering field signal.

[00118] 5. The system of Claim 2, further comprising: an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

[00119] 6. The system of Claim 2, further comprising: wherein the first portion of the instrument and the second portion of the instrument are hingedly moveable relative to one another.

[00120] 7. The system of Claim 1 , further comprising: a display device configured to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

[00121] 8. The system of Claim 1 , further comprising: an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose.

[00122] 9. A method to navigate an instrument for a procedure relative to a subject, comprising: providing an instrument having a first instrument portion and a second instrument portion; providing the second instrument portion with a interfering portion and is moveable relative to the first instrument portion, wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; providing a tracking device with at least one field sensor connected to the first instrument portion, wherein the tracking device includes; configuring a navigation processor to execute instructions for: receiving afield signal from the tracking device based at least in part on sensing an interfering field in the at least one field sensor, determining a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluating the determined pose relative to a planned final pose, and outputting the evaluation of the determined pose relative to the planned final pose.

[00123] 10. The method of Claim 9, further comprising: providing an EM localizer configured to generate a localizer field; configuring the localizer field to produce an interfering field from an interfering portion of the second instrument portion.

[00124] 11. The method of Claim 10, further comprising: configuring the second instrument portion to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00125] 12. The method of Claim 11 , further comprising: measuring and determining a metric at least based on a signal from the tracking device; wherein the measurement and determination of the metric is included in the interfering field signal and the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device.

[00126] 13. The method of Claim 12, further comprising: selecting the metric from at least one of a geometry determination of the tracking device or a phase shift or shifts determination at the tracking device.

[00127] 14. The method of Claim 12, further comprising: providing an implant to be carried by the instrument; configuring the implant so that the planned final pose allows the implant to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

[00128] 15. The method of Claim 12, further comprising: providing a staple to be carried by the instrument; configuring the staple so that the planned final pose allows the staple to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

[00129] 16. The method of Claim 9, further comprising: providing a display device to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

[00130] 17. The method of Claim 9, further comprising: providing an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose.

[00131] 18. A method to navigate an instrument having a first instrument portion and a second instrument portion for a procedure relative to a subject, comprising: receiving an field signal from a tracking device based at least in part on sensing an interfering field in at least one field sensor of the tracking device, determining a measurement of a metric based on the interfering field signal; determining a present pose of the second instrument portion relative to the tracking device based on the determined measurement, evaluating the determined present pose relative to a planned final pose, and outputting the evaluation of the determined present pose relative to the planned final pose.

[00132] 19. The method of Claim 18, further comprising: providing the instrument having the first instrument portion and the second instrument portion having a interfering portion; providing the tracking device connected to the first instrument portion; and providing a navigation processor configured to execute instructions.

[00133] 20. The method of Claim 19, further comprising: providing an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

[00134] 1. A system to navigate an instrument for a procedure relative to a subject, comprising: an instrument having a first instrument portion and a second instrument portion having an interfering portion; a tracking device connected to the first instrument portion, wherein the tracking device includes at least one field sensor and wherein the second instrument portion is moveable relative to the tracking device; wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; a navigation processor configured to execute instructions to: receive afield signal from the tracking device based at least in part on sensing the interfering field at the at least one field sensor, determine a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluate the determined pose relative to a planned final pose, and output the evaluation of the determined pose relative to the planned final pose.

[00135] 2. The system of Claim 1 , further comprising: an electromagnetic (EM) localizer configured to generate a localizer field; wherein the localizer field causes an interfering field in the interfering portion of the second instrument portion.

[00136] 3. The system of Claim 2, wherein the second instrument portion is configured to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00137] 4. The system of Claim 2, wherein the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device; wherein a measurement of a metric with the tracking device is determined from the interfering field signal.

[00138] 5. The system of Claim 2, further comprising: an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

[00139] 6. The system of Claim 2, further comprising: wherein the first portion of the instrument and the second portion of the instrument are hingedly moveable relative to one another. [00140] 7. The system of Claim 1 , further comprising: a display device configured to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

[00141] 8. The system of Claim 1 , further comprising: an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose.

[00142] 9. A method to navigate an instrument for a procedure relative to a subject, comprising: providing an instrument having a first instrument portion and a second instrument portion; providing the second instrument portion with a interfering portion and is moveable relative to the first instrument portion, wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; providing a tracking device with at least one field sensor connected to the first instrument portion, wherein the tracking device includes; configuring a navigation processor to execute instructions for: receiving afield signal from the tracking device based at least in part on sensing an interfering field in the at least one field sensor, determining a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluating the determined pose relative to a planned final pose, and outputting the evaluation of the determined pose relative to the planned final pose.

[00143] 10. The method of Claim 9, further comprising: providing an EM localizer configured to generate a localizer field; configuring the localizer field to produce an interfering field from an interfering portion of the second instrument portion.

[00144] 11. The method of Claim 10, further comprising: configuring the second instrument portion to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00145] 12. The method of Claim 11 , further comprising: measuring and determining a metric at least based on a signal from the tracking device; wherein the measurement and determination of the metric is included in the interfering field signal and the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device.

[00146] 13. The method of Claim 12, further comprising: selecting the metric from at least one of a geometry determination of the tracking device or a phase shift or shifts determination at the tracking device.

[00147] 14. The method of Claim 12, further comprising: providing an implant to be carried by the instrument; configuring the implant so that the planned final pose allows the implant to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

[00148] 15. The method of Claim 9, further comprising: receiving an field signal from a tracking device based at least in part on sensing an interfering field in at least one field sensor of the tracking device, determining a measurement of a metric based on the interfering field signal; determining a present pose of the second instrument portion relative to the tracking device based on the determined measurement, evaluating the determined present pose relative to a planned final pose, and outputting the evaluation of the determined present pose relative to the planned final pose.

[00149] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[00150] Instructions may be executed by a processor and may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules.

[00151] The apparatuses and methods described in this application may be partially or fully implemented by a processor (also referred to as a processor module) that may include a special purpose computer (i.e. , created by configuring a processor) and/or a general purpose computer to execute one or more particular functions embodied in computer programs. The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may include a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services and applications, etc.

[00152] The computer programs may include: (i) assembly code; (ii) object code generated from source code by a compiler; (iii) source code for execution by an interpreter; (iv) source code for compilation and execution by a just-in-time compiler, (v) descriptive text for parsing, such as HTML (hypertext markup language) or XML (extensible markup language), etc. As examples only, source code may be written in C, C++, C#, Objective-C, Haskell, Go, SQL, Lisp, Java®, ASP, Perl, Javascript®, HTML5, Ada, ASP (active server pages), Perl, Scala, Erlang, Ruby, Flash®, Visual Basic®, Lua, or Python®. [00153] Communications may include wireless communications described in the present disclosure can be conducted in full or partial compliance with IEEE standard 802.11 -2012, IEEE standard 802.16-2009, and/or IEEE standard 802.20- 2008. In various implementations, IEEE 802.11 -2012 may be supplemented by draft IEEE standard 802.11ac, draft IEEE standard 802.11 ad, and/or draft IEEE standard 802.11 ah.

[00154] A processor, processor module, module or ‘controller’ may be used interchangeably herein (unless specifically noted otherwise) and each may be replaced with the term ‘circuit.’ Any of these terms may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on- chip.

[00155] Instructions may be executed by one or more processors or processor modules, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” or “processor module” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements. The processor or processors may operate entirely automatically and/or substantially automatically. In automatic operation the processor may execute instructions based on received input and execute instructions in light thereof. Thus, various outputs may be made without further or any manual (e.g., user) input.

[00156] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

[00157] Example 1. A system to navigate an instrument for a procedure relative to a subject, comprising: an instrument having a first instrument portion and a second instrument portion having an interfering portion; a tracking device connected to the first instrument portion, wherein the tracking device includes at least one field sensor and wherein the second instrument portion is moveable relative to the tracking device; wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; a navigation processor configured to execute instructions to: receive afield signal from the tracking device based at least in part on sensing the interfering field at the at least one field sensor, determine a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluate the determined pose relative to a planned final pose, and output the evaluation of the determined pose relative to the planned final pose. [00158] Example 2. The system of Example 1 , further comprising: an electromagnetic (EM) localizer configured to generate a localizer field; wherein the localizer field causes an interfering field in the interfering portion of the second instrument portion.

[00159] Example 3. The system of Example 2, wherein the second instrument portion is configured to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00160] Example 4. The system of Example 2, wherein the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device; wherein a measurement of a metric with the tracking device is determined from the interfering field signal.

[00161] Example 5. The system of Example 2, further comprising: an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

[00162] Example 6. The system of Example 2, further comprising: wherein the first portion of the instrument and the second portion of the instrument are hingedly moveable relative to one another.

[00163] Example 7. The system of Example 1 , further comprising:

[00164] a display device configured to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

[00165] Example 8. The system of Example 1 , further comprising:

[00166] an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose.

[00167] Example 9. A method to navigate an instrument for a procedure relative to a subject, comprising: providing an instrument having a first instrument portion and a second instrument portion; providing the second instrument portion with a interfering portion and is moveable relative to the first instrument portion, wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; providing a tracking device with at least one field sensor connected to the first instrument portion, wherein the tracking device includes; configuring a navigation processor to execute instructions for: receiving afield signal from the tracking device based at least in part on sensing an interfering field in the at least one field sensor, determining a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluating the determined pose relative to a planned final pose, and outputting the evaluation of the determined pose relative to the planned final pose.

[00168] Example 10. The method of Example 9, further comprising: providing an EM localizer configured to generate a localizer field; configuring the localizer field to produce an interfering field from an interfering portion of the second instrument portion.

[00169] Example 11. The method of Example 10, further comprising: configuring the second instrument portion to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

[00170] Example 12. The method of Example 11 , further comprising: measuring and determining a metric at least based on a signal from the tracking device; wherein the measurement and determination of the metric is included in the interfering field signal and the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device.

[00171] Example 13. The method of Example 12, further comprising: selecting the metric from at least one of a geometry determination of the tracking device or a phase shift or shifts determination at the tracking device.

[00172] Example 14. The method of Example 12, further comprising: providing an implant to be carried by the instrument; configuring the implant so that the planned final pose allows the implant to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

[00173] Example 15. The method of Example 12, further comprising: providing a staple to be carried by the instrument; configuring the staple so that the planned final pose allows the staple to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

[00174] Example 16. The method of Example 9, further comprising: providing a display device to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

[00175] Example 17. The method of Example 9, further comprising: providing an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose. [00176] Example 18. A method to navigate an instrument having a first instrument portion and a second instrument portion for a procedure relative to a subject, comprising: receiving an field signal from a tracking device based at least in part on sensing an interfering field in at least one field sensor of the tracking device, determining a measurement of a metric based on the interfering field signal; determining a present pose of the second instrument portion relative to the tracking device based on the determined measurement, evaluating the determined present pose relative to a planned final pose, and outputting the evaluation of the determined present pose relative to the planned final pose.

[00177] Example 19. The method of Example 18, further comprising: providing the instrument having the first instrument portion and the second instrument portion having a interfering portion; providing the tracking device connected to the first instrument portion; and providing a navigation processor configured to execute instructions.

[00178] Example 20. The method of Example 19, further comprising: providing an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

Claims

CLAIMS What is claimed is:

1. A system to navigate an instrument for a procedure relative to a subject, comprising: an instrument having a first instrument portion and a second instrument portion having an interfering portion; a tracking device connected to the first instrument portion, wherein the tracking device includes at least one field sensor and wherein the second instrument portion is moveable relative to the tracking device; wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; a navigation processor configured to execute instructions to: receive afield signal from the tracking device based at least in part on sensing the interfering field at the at least one field sensor, determine a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluate the determined pose relative to a planned final pose, and output the evaluation of the determined pose relative to the planned final pose.

2. The system of Claim 1 , further comprising: an electromagnetic (EM) localizer configured to generate a localizer field; wherein the localizer field causes an interfering field in the interfering portion of the second instrument portion.

3. The system of Claim 2, wherein the second instrument portion is configured to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

4. The system of Claim 2, wherein the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device; wherein a measurement of a metric with the tracking device is determined from the interfering field signal.

5. The system of Claim 2, further comprising: an implant configured to be carried by the instrument; wherein the planned final pose allows the implant to be positioned in the subject; wherein the measurement of the metric is operable to confirm the planned final pose.

6. The system of Claim 2, further comprising: wherein the first portion of the instrument and the second portion of the instrument are hingedly moveable relative to one another.

7. The system of Claim 1 , further comprising: a display device configured to display a graphical representation based on the output evaluation of the determined pose relative to the planned final pose.

8. The system of Claim 1 , further comprising: an audio output system configured to emit an audible sound based on the output evaluation of the determined pose relative to the planned final pose.

9. A method to navigate an instrument for a procedure relative to a subject, comprising: providing an instrument having a first instrument portion and a second instrument portion; providing the second instrument portion with a interfering portion and is moveable relative to the first instrument portion, wherein at least the interfering portion of the second instrument portion is configured to generate an interfering field based on the interfering portion; providing a tracking device with at least one field sensor connected to the first instrument portion, wherein the tracking device includes; configuring a navigation processor to execute instructions for: receiving afield signal from the tracking device based at least in part on sensing an interfering field in the at least one field sensor, determining a pose of the second instrument portion relative to the tracking device based on the received interfering field signal, evaluating the determined pose relative to a planned final pose, and outputting the evaluation of the determined pose relative to the planned final pose.

10. The method of Claim 9, further comprising: providing an EM localizer configured to generate a localizer field; configuring the localizer field to produce an interfering field from an interfering portion of the second instrument portion.

11 . The method of Claim 10, further comprising: configuring the second instrument portion to move from a proximate position to a remote position; wherein the interfering field sensed by the tracking device varies between the proximate position and the remote position.

12. The method of Claim 11 , further comprising: and determining a metric at least based on a signal from

the tracking device; wherein the measurement and determination of the metric is included in the interfering field signal and the interfering field signal varies with the variation of the interfering field that is sensed by the tracking device.

13. The method of Claim 12, further comprising: selecting the metric from at least one of a geometry determination of the tracking device or a phase shift or shifts determination at the tracking device.

14. The method of Claim 12, further comprising: providing an implant to be carried by the instrument; configuring the implant so that the planned final pose allows the implant to be positioned in the subject; confirming the planned final pose by the measurement of the metric.

15. The method of Claim 9, further comprising: receiving an field signal from a tracking device based at least in part on sensing an interfering field in at least one field sensor of the tracking device, determining a measurement of a metric based on the interfering field signal; determining a present pose of the second instrument portion relative to the tracking device based on the determined measurement, evaluating the determined present pose relative to a planned final pose, and outputting the evaluation of the determined present pose relative to the planned final pose.