WO2025158335A1

WO2025158335A1 - Configurable reference frame device and method of using the same

Info

Publication number: WO2025158335A1
Application number: PCT/IB2025/050757
Authority: WO
Inventors: Ma Luo; Victor SNYDER; Jeannine ELLIOTT; Emily OSMAN; Nicholas RAWLUK; Robert Pahl; Morgan ARVISAIS; Sarah VERDERAME
Original assignee: Medtronic Navigation Inc
Current assignee: Medtronic Navigation Inc
Priority date: 2024-01-26
Filing date: 2025-01-24
Publication date: 2025-07-31
Anticipated expiration: 2026-07-26

Abstract

A method and system for operating a navigation system includes fixing a configurable reference frame to a patient. The configurable reference frame has a body with at least one moveable arm moveable relative to a body. Also disclosed is registering a position of the configurable reference frame and performing a procedure with the configurable reference frame in a selected configuration.

Description

CONFIGURABLE REFERENCE FRAME DEVICE AND METHOD OF USING

THE SAME

FIELD

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/625,464, filed 26 January 2024, the entire content of which is incorporated herein by reference.

[0002] The present disclosure relates generally to a navigated procedure on a subject, and particularly to a navigated procedure using a configurable reference frame device to automatically register subject space to image space.

BACKGROUND

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] A subject, such as a human patient, may undergo a procedure. The procedure may include a surgical procedure to correct or augment an anatomy of the subject. The augmentation of the anatomy can include various procedures, such as movement or augmentation of bone, insertion of an implant (i.e., an implantable device), or other appropriate procedures.

[0005] In performing a procedure, a user, such as a surgeon, can perform a procedure on a subject with a navigation system. The navigation system can assist in determining the location of a subject and tracked device so that the relative position of the device to the subject may be tracked. [0006] Image data is acquired of the subject for display prior to, during, and after a procedure on the subject. The image, including the image data which generates or is used to render the image, can be registered to the subject. The image data can define an image space that can include a three-dimensional space. The subject can likewise define a three-dimensional physical space to which the image data is registered. Registration can be performed in a plurality of processes.

[0007] A navigation system can use a selected tracking modality. The tracking system can include a localizer that generates or views the navigation field. For example, an optical tracking system can include one or more cameras as a localizer that views visible or infrared sources or reflectors. Alternatively, or in addition to an optical system, an electromagnetic navigation system (EM navigation system) can be used. In the EM system, one or more coils generate a field that is sensed by one or more sense coils to determine the location of an instrument.

[0008] Registration devices mounted to the subject are used for tracking the position of the subject. The reference frames may be referred to as a reference frame or dynamic reference frame. Different registration device designs are used in various modalities. Different versions of systems within a modality may also use different registration device designs. Generally, larger registration devices are more desirable to increase accuracy. However, certain systems may be volume restricted. Different procedures may require tool access close to the reference location requiring a small reference. Therefore, different size reference devices are available to accommodate various conditions. Additionally, users need to be aware of which reference frames are compatible with which procedures and equipment, leading to potential surgery interruption and user frustration. The overhead for a facility in providing many different reference frame designs for the different modalities and versions of systems is inconvenient.

SUMMARY

[0009] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0010] According to various embodiments, a method and system for operating a navigation system includes fixing a configurable reference frame to a patient. The configurable reference frame has at least one extendable arm that is extendable from a body. The extendable arm may have a trackable portions associated therewith and moveable relative to the body. The trackable portions may move in a plane. The plane may be defined by the body. The trackable portions may be moved in the same plane as the body or parallel to the plane defined by the body.

[0011] In various embodiments, a method of operating a navigation system includes fixing a configurable reference frame to a patient. The configurable reference frame has at least one extendable arm that is extendable from a body. The body may comprise fiducial markers associated therewith. The method includes imaging the patient with the configurable reference frame with the extendable arm in a first position, registering the reference frame and determining an origin position of the reference frame based on the fiducial markers. The extendable arm may be moved from a retracted position to an extended position relative to the body to form a selecting configuration, and performing a navigation guided procedure with the configurable reference frame in the first position and maintaining the origin after moving the extendable arm.

[0012] In another aspect of the disclosure, a reference frame for guided surgery includes a body having a planar first surface and a second surface. The body has a central portion and a plurality of arms that may have at least a portion that is coplanar with or in a plane parallel to the planar surface and extending from the central portion. The body further has an electromagnetic tracking device mount position. The body may further comprise a plurality of fiducial markers that may correspond to one or more imaging modalities. At least one of the arms comprises a first extendable arm extending from the first arm wherein the first extendable arm has a first end and a second end. An optical reference may be disposed on the first end of the first extendable arm.

[0013] 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

[0014] 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.

[0015] FIG. 1 is an environmental view of a navigation system in an operating theatre. [0016] FIG. 2 is a detailed schematic view of an imaging system with a source and detector configured to move around a subject, according to various embodiments.

[0017] FIG. 3 is a side view of a dynamic reference frame having a movable arm attached thereto, according to various embodiments.

[0018] FIG. 4A is a top view of a first example of a dynamic reference frame having movable arms.

[0019] FIG. 4B is a bottom view of the dynamic reference frame of FIG.4A.

[0020] FIG. 5A is a top view of a dynamic reference frame having movable arms, according to various embodiments.

[0021] FIG. 5B is a bottom view of the dynamic reference frame of FIG.5A.

[0022] FIG. 5C is a top view of the dynamic reference frame of FIG. 5A having in a third geometry.

[0023] FIG. 6 is a flowchart of a method for performing navigation using the dynamic reference frame with movable arms.

[0024] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings. [0026] A subject may be imaged with an imaging system, as discussed further herein. The subject may be a living subject, such as a human patient. Image data may be acquired of the human patient and may be combined to provide an image of the human patient that is greater than any dimension of any single projection acquired with the imagining system. It is understood, however, that image data may be acquired of a non-living subject, such an inanimate subject including a housing, casing, interior of a super structure, a phantom (e.g., anatomical phantom), or the like. For example, image data may be acquired of an airframe for various purposes, such as diagnosing issues and/or planning repair work.

[0027] With reference to FIG. 1 and FIG. 2, a schematic view of a navigation system 20 is illustrated. A user 24, such as a surgeon, can perform a procedure on a subject, such as a patient 28. The patient 28 may be placed on a support, such as a table 32 for a selected portion of the procedure. The table 32 may not interfere with image data acquisition with an imaging system 36. In performing the procedure, the user 24 can use the imaging system 36 to acquire image data of the patient 28 to allow a selected system to generate or create images to assist in performing a procedure. Images generated with the image data may be two-dimensional (2D) images, three-dimensional (3D), or appropriate type of images, such as a model (such as a three-dimensional (3D) image), long views, single projections views, etc. can be generated using the image data and displayed as an image 40 on a display device 44. The display device 44 can be part of and/or connected to a processor system 48 that includes a user interface 52, such as a keyboard, mouse, stylus, a touch screen as part of the display device 44 or combinations thereof. A processor 56 can include one or more processors, processor module, and/or microprocessors incorporated with the processing system 48 along with selected types of non-transitory and/or transitory memory 58. A connection 62 can be provided between the processor 56 and the display device 44 for data communication to allow driving the display device 44 to display or illustrate the image 40. The processor 56 may be any appropriate type of processor or processor module such as a general-purpose processor that executes instructions included in a program or an application specific processor such as an application specific integrated circuit.

[0028] The imaging system 36 can include but is not limited to an 0- Arm® imaging system sold by Medtronic Navigation, Inc. having a place of business in Louisville, CO, USA. The imaging device or system 36 may be an additional or alternative imaging system that may be used to acquire pre-, intra-, or post-operative or real-time image data of a subject, such as the subject. 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 device comprises an 0-arm® imaging device sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colorado, USA. The imaging device may have a generally annular gantry housing in which an image capturing portion is moveably placed. The imaging device 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 device 80 may include in addition or alternatively a fluoroscopic C- arm. Other exemplary imaging devices may include fluoroscopes such as bi-plane 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 magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, etc. All of the imaging systems may be used to acquire image data at any appropriate time, including after connecting the DRF 140 to the patient 28.

[0029] The imaging system 36, when, for example, including the 0- Arm® imaging system, may include a mobile cart 60 that includes a controller and/or control system 64. The control system 64 may include a processor and/or processor system 68 (similar to the processor 56), a user interface 67 such as a keyboard, a mouse, a touch screen, a memory 58 (e.g., a non-transitory memory) and a display device 69. The memory system 66 may include various instructions that are executed by the processor 68 that acts as a controller to control the imaging system 36, including various portions of the imaging system 36.

[0030] The imaging system 36 may include further additional portions, such as an imaging gantry 70 in which is positioned a source unit (also referred to as a source assembly) 74 and a detector unit (also referred to as a detector assembly) 78. In various embodiments, the detector 78 alone and/or together with the source unit may be referred to as an imaging head of the imaging system 36. The gantry 70 is moveably connected to the mobile cart 60. The gantry 70 may be O-shaped or toroid shaped, wherein the gantry 70 is substantially annular and includes walls that form a volume in which the source unit 74 and detector 78 may move. The mobile cart 60 may also be moved. In various embodiments, the gantry 70 and/or the cart 60 may be moved while image data is acquired, including both being moved simultaneously. Also, the imaging system 36 via the mobile cart 60 can be moved from one operating theater to another (e.g., another room). The gantry 70 can move relative to the cart 60, as discussed further herein. This allows the imaging system 36 to be mobile and moveable relative to the subject 28, thus allowing it to be used in multiple locations and with multiple procedures without requiring a capital expenditure or space dedicated to a fixed imaging system.

[0031] The processor 68 may be a general-purpose processor or an application specific application processor. The memory system 66 may be a non- transitory memory such as a spinning disk or solid-state non-volatile memory. In various embodiments, the memory system may include instructions to be executed by the processor 68 to perform functions and determine results, as discussed herein. The memory system 66 may be used to store images from the imaging system 36 to allow calculations to be performed thereon. The memory system 66 may be used to store intermediate and final calculations, such as data for identifying body structures, distance for the imaging system to travel, a target position for the imaging system 36.

[0032] In various embodiments, the imaging system 36 may include an imaging system that acquires images and/or image data using emitting x-rays and detecting x-rays after interactions and/or attenuations of the x-rays with or by the subject 28. The x-ray imaging may be an imaging modality. It is understood that other imaging modalities are possible, such as other high energy beams, etc. Also, imaging systems may include magnetic resonance imaging systems (MRI), computed tomography imaging systems (CT), cone beam x-ray imaging systems, etc. As discussed herein, the imaging systems may acquire image data of the patient 28 and include fiducial image data acquired of a fiducial assembly.

[0033] Thus, in the imaging system 36, the source unit 74 may be an x- ray emitter that can emit x-rays at and/or through the patient 28 to be detected by the detector 78. As is understood by one skilled in the art, the x-rays emitted by the source 74 can be emitted in a cone 90 along a selected main vector 94 and detected by the detector 78, as illustrated in FIG. 2. The source 74 and the detector 78 may also be referred to together as a source/detector unit 98, especially wherein the source 74 is generally diametrically opposed (e.g., 180 degrees (°) apart) from the detector 78 within the gantry 70.

[0034] The imaging system 36 may move, as a whole or in part, relative to the subject 28. For example, the source 74 and the detector 78 can move around the patient 28, e.g., a 360° motion, spiral, portion of a circle, etc. The movement of the source/detector unit 98 within the gantry 70 may allow the source 74 to remain generally 180° opposed (such as with a fixed inner gantry or rotor or moving system) to the detector 78. Thus, the detector 78 may be referred to as moving around (e.g., in a circle or spiral) the subject 28 and it is understood that the source 74 remains opposed thereto, unless disclosed otherwise. Also, the gantry 70 can move isometrically (also referred as “wag”) relative to the subject 28 generally in the direction of arrow 100 around an axis 102, tilt relative to a longitudinal axis 106 of the patient 28 illustrated by arrows 110. The gantry 70 may also move longitudinally in the direction of arrows 114 along the axis 106 relative to the subject 28, up and down generally in the Y-axis direction of arrows 118 relative to the cart 60 and/or the subject 28, generally transverse to the axis 106 and parallel with the axis 102. The gantry may also be moved in an X direction in the direction of the arrows 116 by moving the wheels 117.

[0035] The movement of the imaging system 36, in whole or in part is to allow for positioning of the source/detector unit (SDU) 98 relative to the subject 28. The imaging system 36 can be precisely controlled to move the SDU 98 relative to the subject 28 to generate precise image data of the subject 28.

[0036] According to various embodiments, the imaging system 36 can be used with an un-navigated or navigated procedure. In a navigated procedure, a localizer and/or digitizer, including either or both of an optical localizer 130 and/or an electromagnetic localizer 138 can be used to generate a field and/or receive and/or send a signal within a navigation domain relative to the subject 28. The navigated space or navigational domain relative to the subject 28 can be registered to the image 40. Correlation, as understood in the art, is to allow registration of a navigation space defined within the navigational domain and an image space defined by the image 40. A patient tracker or dynamic reference frame 140 can be connected to the subject 28 to allow for a dynamic registration and maintenance of registration of the subject 28 to the image 40.

[0037] A patient tracking device or dynamic reference frame or frame

(DRF) 140 and an instrument 144 can then be tracked by a tracking system 50 relative to the subject 28 to allow for a navigated procedure. The DRF and instrument 144 can include a tracking device, such as an optical tracking device 148 and/or an electromagnetic tracking device 152 to allow for tracking of the DRF 140 and instrument 144 with either or both of the optical localizer 130 or the electromagnetic localizer 138. A navigation/probe interface device 158 may have communications (e.g., wired or wireless) with the instrument 144 (e.g., via a communication line 156), with the electromagnetic localizer 138 (e.g., via a communication line 162), and/or the optical localizer 130 (e.g., via a communication line 166). The interface 158 can also communicate with the processor 56 with a communication line 168 and may communicate information (e.g., signals) regarding the various items connected to the interface 158. It will be understood that any of the communication lines can be wired, wireless, physical media transmission or movement, or any other appropriate communication. Nevertheless, the appropriate communication systems can be provided with the respective localizers to allow for tracking of the DRF 140 and instrument 144 relative to the subject 28 to allow for illustration of a tracked location of the DRF 140 and instrument 144 relative to the image 40 for performing a procedure.

[0038] One skilled in the art will understand that the instrument 144 may be any appropriate instrument, such as a ventricular or vascular stent, spinal implant, neurological stent or stimulator, ablation device, or the like. The instrument 144 can be an interventional instrument or can include or be an implantable device. Tracking the instrument 144 allows for viewing a pose (including x,y,z position and orientation) of the instrument 144 relative to the subject 28 with use of the registered image 40 without direct viewing of the instrument 144 within the subject 28.

[0039] 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® or S7™ tracking systems having an optical localizer, that may be used as the optical localizer 88, and sold by Medtronic Navigation, Inc. of Louisville, 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.

[0040] Further, the imaging system 36, such as the gantry 70, can include an optical tracking device 174 and/or an electromagnetic tracking device 178 to be tracked with the respective optical localizer 130 and/or electromagnetic localizer 138. Accordingly, the imaging system 36 can be tracked relative to the subject 28 as can the DRF 140 and instrument 144 to allow for initial registration, automatic registration, or continued registration of the subject 28 relative to the image 40. Registration by tracking the imager itself (e.g., 0-arm autoregistration) may allow for registration and/or autoregistration. Registration and navigated procedures are discussed in the above incorporated U.S. patents and may also include techniques and systems disclosed in U.S. Pat. No. 7,570,791 , U.S. Pat. No. 8,238,631 , 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.

[0041] Briefly, registration may include a translation map to be generated of the physical location of the instrument 144 relative to the image space of the image data and the image 40. The translation map allows the tracked position of the instrument 144 to be displayed on the display device 44 relative to the image 40. A graphical representation 180, also referred to as an icon, can be used to illustrate the location of the instrument 144 relative to the image data 40.

[0042] Upon registration and tracking of the instrument 144, an icon or graphical representation 180 may be displayed relative to, including overlaid on, the image 40. The image 40 may be an appropriate image and may include a 2D image, a 3D image, or any appropriate image as discussed herein.

[0043] With continuing reference to FIG. 2, according to various embodiments, the source 74 can include a single assembly that may include a single x-ray tube 190 that can be connected to a switch 194 that can interconnect a first power source 198 via a connection or power line 200. As discussed above, x-rays can be emitted from the x-ray tube 190 generally in the cone shape 90 towards the detector 78 and generally in the direction from the x-ray tube 190 as indicated by arrow, beam arrow, beam or vector 94. Thus, the imaging system 36 may be a duel or multiple energy x-ray image acquisition system.

[0044] The subject 28 can be positioned within the x-ray cone 90 to allow for acquiring image data of the subject 28 based upon the emission of x-rays in the direction of vector 94 towards the detector 78. Images may be generated from the image data based on the x-ray projections and may be two-dimensional, three- dimensional, or any appropriate type of image. For reconstructing or forming the 3D volumetric image, appropriate techniques include Expectation maximization (EM), Ordered Subsets EM (OS-EM), Simultaneous Algebraic Reconstruction Technique (SART) and Total Variation Minimization (TVM), as generally understood by those skilled in the art. Various reconstruction techniques may also and alternatively include machine learning systems and algebraic techniques.

[0045] The dynamic reference frame 140 may be affixed externally to the patient 28, adjacent to the region of navigation, such as on the patient’s skull, chest, spine, etc. The dynamic reference frame 140 can be affixed to the patient’s skin, by way of a selected adhesive patch and/or a tensioning system. The dynamic reference frame 140 may also be removably attachable to a fiducial marker or have a fiducial marker incorporated therein as described below. The dynamic reference frame 140 can be connected to a bone portion of the anatomy, such as the skull. The bone portion can be adjacent, the area of the procedure, the bone of the procedure, or any appropriate bone portion. [0046] Briefly, registration allows the navigation system 20 to operate and illustrate a tracked pose of the instrument 144 as the graphical representation 180 with the image 40. A map is created between all points in the image data or image space and the corresponding points in the patient’s anatomy in subject or patient space. The map may be established by executing instructions based on determined common or fiducial points in both the image space and the navigation space. Each of the systems described above may also be incorporated into a single system or executed by a single processor.

[0047] To register the patient 28 to the image 40, the user 24 may use point registration and/or surface registration. Other registration techniques may include appropriate techniques, including those discussed herein. Generally, the DRF 140 is first attached to the patient 28 prior to an image data acquisition. Point registration then proceeds by selecting and storing particular points from the acquired images and then touching the corresponding points or selected points (e.g., divots as discussed herein at known poses relative to fiducials) on the DRF 140 with a tracked pointer probe or any appropriate tracked device, such as the instrument 144 and/or recalling predetermined known poses of the fiducials in the DRF 140 to the tracked portions thereof. The navigation system 20 analyzes the relationship between the two sets of points that are selected and computes a match, which allows for a determination of a correlation of every point in the image data or image space with its corresponding point on the patient’s anatomy or the patient space.

[0048] In order to maintain registration accuracy, the navigation system

20 continuously can track the position of the patient 28 during registration and navigation with the dynamic reference frame 140. This is because the patient 28, dynamic reference frame 140, and localizer 138 may all move during the procedure, even when this movement is not desired. The dynamic reference frame 140 allows the tracking system 50 to track the anatomy and can assist in registration. Because the dynamic reference frame 140 is rigidly fixed to the patient 28 at least with a fixation portion, as discussed herein, any movement of the anatomy or the localizers 130, 138 is detected as the relative motion between the localizer 130, 138 and the dynamic reference frame 140. This relative motion is communicated to the processor system 48, such as via the coil array controller 160, via the navigation probe interface 158, which updates the registration correlation to thereby maintain accurate navigation. The optical localizer 130 may also communicate via the controller 160 and/or directly with the workstation processor system 48 to communicate the tracked potion of the various tracking devices.

[0049] The tracking system 50, if it is using an electromagnetic tracking assembly, can work by positioning the EM localizer 138 near the subject space to generate an electromagnetic (EM) field, which can be low energy and also generally referred to as a navigation field. Because every point in the navigation field or patient space is associated with a unique field strengths and directions, the electromagnetic part of the tracking system 50 can determine the position of the DRF 140 and instrument 144 by measuring the field strengths, directions, and/or components thereof at the tracking device location. If the tracking system 50 is using the optical localizer 130, the one or more cameras view the subject and define the subject space which can also be referred to as the navigation space. The optical portion of the tracking system 50 can use one or more cameras to define the navigation space. For example, a view of the tracking devices can be used to determine a distance, such as by triangulation from the optical localizer 130 to determine a location of the tracked device.

[0050] The instrument 144 can be any appropriate instrument (e.g., a catheter, a probe, a guide, etc.) and can be used for various mechanisms and methods, such as delivering a material to a selected portion of the patient 28, such as within the cranium or spine. As discussed further herein, the instrument 144 can be precisely positioned via the navigation system 20 and otherwise used to achieve a protocol for positioning the material relative to the patient 28 in any appropriate manner. The instrument 144 may also include a brain probe to perform deep brain stimulation. The instrument can also be used to track the user 24.

[0051] The dynamic reference frame 140 is fixed to the patient 28 to identify the position of the patient 28 in the navigation field. The tracking system 50 continuously recomputes the relative position (including location and orientation) of the dynamic reference frame 140 and the instrument 144 during localization and relates this spatial information to patient registration data to enable image guidance of the instrument 144 within and/or relative to the patient 28.

[0052] Referring now to FIG. 3, to obtain a maximum accuracy it can be selected to fix the dynamic reference frame 140 to the patient 28. Thus, the dynamic reference frame 140 or any tracking device fixed relative to the patient 28 allows for determination of three special dimensions and all of yaw, pitch, and roll relative to all or at least the portion of the patient 28 to which it is attached. Any appropriate coordinate system can be used to describe the various degrees of freedom. Fixing the dynamic reference frame 140 relative to the patient 28 in this manner can assist in maintaining maximum accuracy of the navigation system 20.

[0053] As discussed above, registration can occur between image data of the patient that can be displayed as the image on the display device and the navigation space defined by the localizer and/or the patient 28. As an example, the tracking system 50 can track the dynamic reference frame 140 that is associated with the patient 28, the DRF 140 discussed in general above. The dynamic reference frame 140 can be interconnected with the patient 28 in any appropriate manner or at a location appropriate for a selected procedure. For example, the DRF 140 may include a connection arm 310 that may be adjustable in any appropriate manner. The arm 310 can be connected with a selected vertebra of the patient with a fixation or mounting portion 312, such as with a fixation clamp, a screw, a pint, etc. The mounting portion 312 may include a screw or other types affixing mechanisms such as those set forth in U.S. Pat. No. 10,531 ,814 issued January 4, 2020, entitled “Method and Apparatus for Moving a Reference Frame,” and/or U.S. Pat. No. 11 ,462,242, both of which are incorporated by reference herein.

[0054] The mounting arm 310 may be movable about a first pivot axis 316 and a second pivot axis 318. The arm 310 may also be formed of two parts 310A and 310B. In this example, part 310A is slidably received within part 310B to allow the distance of the dynamic reference frame 140 to be adjusted relative to the mounting portion 312. The pivot axes 316, 318 may be formed by pins that are positioned between the two arms 310A, 310B. The pivot 316 allows the dynamic reference frame 140 to pivot into and out of the page while pivot 318 allows pivoting right and left.

[0055] The arm 310 is affixed to the dynamic reference frame 140 by an attachment 320. The attachment 320 may be a bracket, glue, screws welding or other means. The arm 310 may be removably fixed to the DRF 140. The DRF 140, however, is generally immovably fixed to at least a portion of the arm 310, such as the arm 310A.

[0056] The dynamic reference frame 140 may have a body 328 that has at least a first side 330 that is generally planar and a second side 332, which are exterior surfaces of the DRF 140. Fiducials 334 may be embedded in or coupled to the body 328. The fiducials 334 will be further described in detail below. In general, the fiducials 334 are used to provide a means for registering the dynamic reference frame 140 in navigation domain defined by the navigation system 50 to images in various modalities therein. The fiducials 334 may be made of materials that are imageable, such as imageable in MRI or CT imaging modalities. The fiducials may be mounted to the body 328 or embedded in the body 328 (e.g., molded into the body or fit in bore therein. The fiducial 334 are fixed in selected and known poses in the body 328. The fiducials 334 may then be imaged and appear in the image. The fiducial image portions may then be identified automatically or by the user 24.

[0057] Trackable portions may be placed with the DRF 140, as discussed herein. The trackable portions may be optically tracked portions 340 (e.g., passive reflectors or active emitter members), electromagnetically tracked portions, or any appropriate tracked portions. The optically tracked portions 340 may be placed on one or more extendable arms.

[0058] The dynamic reference frame 140 is a configurable DRF that may also be referred to as a universal and/or multi-purpose DRF for medical image registration and surgical navigation. The registration may be automatic, manual, or combinations thereof. The configurable DRF 140 may be a single or only DRF 140 that may be used with a plurality of different tracking systems and/or imaging modalities. By providing a universal DRF, a reduction of an overall number of navigational and reference frames may be realized. The dynamic reference frame 140 may also be used for devices from various manufacturers.

[0059] The dynamic reference frame 140 may be used to define an origin 350 (0, 0, 0) of a coordinate system of the navigation system. That is, the origin 350 may be defined relative to the fiducials 334 and allow the position of various devices within the navigation system 50 to be measured relative thereto. The origin 350 may be any defined point relative to the DRF 140, including the body 328. In various embodiments, the origin 350 may be defined relative to the fiducials 334. Thus, the origin 350 may be defined in the image including the fiducial image portions and relative to the DRF 140 that is tracked in the navigation space and coordinate system.

[0060] Referring now to FIGS. 4A and 4B, the upper surface 330 of the dynamic reference frame 140 is illustrated in FIG. 4A and the bottom surface 332 is illustrated in FIG. 4B. The origin 350 is also illustrated. It should be noted that the origin 350 may be positioned at various locations including at the mounting position 410 on the bottom surface 332 of the dynamic reference frame 140. The mounting position 410 is the position where the arm 312 is attached to the body 328. The origin 350 may be defined as any point relative to the fiducials 334 and/or the trackable portions 340 or other tracked portion. Generally, the original 350 is defined relative to the body 328 as the body is rigid and other portions (e.g., the arms) are moveable relative thereto.

[0061] As discussed above the DRF 140 includes the body 328. The body 328 may include a planar surface, including at least one of the first surface 330 or the second surface 332. The body may also include any appropriate dimensions, such as a thickness or distance 352 between the surfaces 330, 332. The thickness or distance 352 may allow for the definition of an exterior wall or a surface 354 of the body 328.

[0062] The body 328 may further include or define a main or central region 422 from which the arms 410 then may extend. The arms 410 may include or have positioned relative thereto movable or extendable arms 432. The movable arms 432 may move relative to the body 328, such as generally in the direction of arrows 442. It is understood that one or plurality of the movable arms 432 may be provided to move relative to the body 328. Any appropriate number of the arms 432 may be provided and four is merely exemplary.

[0063] Further each of the portions of the DRF 440 may be formed of selected materials. For example, the body 328 and the arms 432 may be formed of a MRI compatible material such as a polyetheretherketone (PEEK) or other nonmagnetic material, such as titanium or titanium alloys. The MRI compatible material may allow the DRF 140 to be placed into a MRI imaging system, such as when connected to the subject 28. As discussed above, the subject 28 may be imaged with the imaging system 36 or with any other appropriate imaging system, such as a MRI imaging system. The DRF 140, however, may include the fiducial 334 that may be imageable in any appropriate imaging system. For example, the fiducials 334 may be formed of a material, such as a ceramic material member, PEEK material member with a selected material encapsulated thereby or formed therewith (e.g. a polar material), that may be imaged in one or more imaging modalities such as in an X-ray imaging system (including CT imaging systems), MRI imaging systems, or other appropriate imaging systems. Therefore, image data may be acquired and an image is generated with the selected imaging system of the subject including the DRF 140. The image of the DRF 140 with the fiducial portions 334 will allow an image to include or have defined therein image fiducial portions 334i that may be displayed with the image on the display device 44.

[0064] The movable arms 432 are moveably coupled to the body 420 by retainers 440 in this example. The retainers 440 may be coupled to the bottom surface 332. However, the retainers 440 may be coupled to the upper surface 330, the bottom surface 332, the sidewall surface 354, or any combination thereof. In this example, the retainers 440 are L-shaped. Thus, the retainers 440 may form or define a track in which the arms 432 may slidably move relative to the body 328. The retainers, however, may be any appropriate shape and be provided in any appropriate numbers to allow selected and defined movement of the arms 432 relative to the body 328. [0065] The retainers 440 may provide a friction fit so that the arms maintain their position during a procedure but can be moved under force to the desired position. The retainers 440 may, however, also provide a positive connection with the arms 432. For example, the arms 432 may include an indent or detent that is engaged by the retainers 440 to maintain the arms 432 in a selected position. The arms 432 move in the direction of the arrows 442 which may be in or parallel to the same plane as the body 422.

[0066] The arms 432 may move relative to the body 328 as discussed above. The arms 432 may have the trackable portions 340 associated therewith. In various examples, as discussed above, the trackable portions 340 may be optical trackable members such as reflectors or active emitters. The trackable portions 340 may, however, move relative to the body 328. For example, as illustrated in Fig. 4A, the movable arm 432 may move in the direction of arrow 442, such as to move the trackable portion 340 from a first position 340a to a second position 340b illustrated in phantom thus the trackable portion 340 may be moved relative to the origin 350. In moving the trackable portion 340 relative to the origin 350, the configuration of the trackable portions 340 of the DRF 140 may change. Nevertheless, as discussed above, the trackable portions 340 may move generally in a plane that is parallel to the plane of the body 328, such as defined by the surface 330. Therefore, the tracking system may track the trackable portion 340 and understand the plane of the DRF 140 even if the relative position of the trackable portion 340 has moved relative to the origin 350. The origin 350 of the DRF 140 may be defined at an initial step, as discussed herein, and movement of the trackable portion 340 may not alter the definition thereof if a selected geometry of the DRF 140 does not change, such as the trackable portion 340 being maintained in a selected plane.

[0067] Further, however, other tracking portions may be associated with the DRF 140. In various embodiments, for example, an EM tracking portion 436 may be connected at a connection or mounting point or position 438 on the body 328. The connection position 438 may be known for the EM tracking device 436. Therefore, the pose of the EM tracking device relative to the origin 350 may also be known for the DRF 140. The EM tracking device 436 may be associated with the DRF 140 to allow for tracking of the DRF 140 with an EM tracking system, as discussed above. Further, due to the known position of the mounting position 438 for the EM tracking device 436 the pose of the origin 350 may also be known.

[0068] Thus, the DRF 140 may be provided with the movable arms 432 to selectively position the tracking portions 340 relative to the body of 328. The EM mounting position 438 may also be known for mounting the EM tracking device 436. The origin 350 defined by the DRF 140 is thus able to be determined relative to the navigation coordinate space.

[0069] The DRF 140 may include one or more divots or reference points 443, 444, and 446. The divots or reference points 443-446 may be usable to allow for contact of the instrument 144, such as a distal tip 144t thereof. The pose of the instrument 144 may be known relative to the DRF 140 when contacting the divot. As discussed above, the instrument 144 may have one or more tracking devices associated therewith and the touching of the tip 144t of the instrument 144 to one or more of the divots 443, 444, 446 may be used to correlate a tracked pose of the instrument 144 to the DRF 140 and the navigation space.

[0070] The body 328 may also have associated therewith one or more fiducials, as noted above. The fiducials 334 may be positioned on the body 328 in any appropriate manner. For example the body 328 may be formed of a polymer and the fiducials may be molded therewith. The fiducials 334 may also affix to the body 328 such as with a connector or adhesive. Further the body 328 may define a bore or divot to receive the fiducial 334 to which it is then fixed or mounted. The fiducials 334, as discussed above, may be imaged in the image data. As noted above the fiducials 334 may be imaged in any appropriate type of image data such as a CT image data, X-ray image data, MRI image data, or the like. Thus, the DRF 140 may be attached to the patient 28 during an imaging procedure to image the patient and the fiducials 334 in the DRF 140.

[0071] The fiducials may then appear in the image data as fiducial portions or image portions 334i. The fiducial portions 334i allow for a determination of a pose of the DRF 140 in the image data for automatic registration to the subject in the coordinate space of the navigation system, as discussed above. The fiducials 334, therefore, may be provided in any appropriate manner. Further, the fiducials may be formed of a selected material such as the material that is both radiopaque for CT or X-ray imaging and MRI compatible for MRI imaging. This may allow the DRF 140 to be usable in a plurality of imaging systems. The fiducial 334 therefore may be formed of a ceramic, an impregnated ceramic, a selected polymer, and/or polymer that encapsulates a selected material such as a polar material. [0072] The DRF 140 therefore may have a configurable geometry that allows the trackable portions 340 to be positioned relative to the origin 350 defined at the DRF. Further the body 328 may have the mounting position 438 for a selected tracking device such the EM tracking device 436. Thus, the single DRF 140 may be usable with the plurality of tracking systems and imaging modalities. Only the single DF 140 may be usable with a plurality of systems to thereby reduce the capital cost or storage of a plurality of DRF for various in multiple systems.

[0073] According to various embodiments, the DRF 140 may also be provided as an alternative system to a system that includes various and/or numerous portions that are similar to those discussed above with variations as discussed herein. According to various embodiments, for example as illustrated in FIG. 5A and 5B, a DRF 140' is illustrated. The DRF 140' may have portions that are similar to those discussed above where similar or identical portions may have the same reference angles augmented with a prime ('). According to various embodiments the DRF 140' may include a body 328’. The body may have two or more surfaces such as a first and second surface 330', 332'. The surfaces 330', 332' may be generally planar and parallel, similar to the body 328 discussed above. Further the body 328’ may include a side wall 354’ that may be defined as a distant or may define a distance 352’ between the two surfaces 330', 332'. The thickness 352' may allow for receiving a movable arm 432'. As discussed herein, the movable arm 432’ may be slidably moved along an axis to various position while at least a portion of the arm

432' is received between the surfaces for 330', 332'. [0074] The one or more movable arms 432' are received in a channel 512 that is disposed within and extends into the body 328’. At least one of the fixed arms 430’ has a movable arm 432'. In this example, all of the arms 430’ have a movable arm 432' but only one of which is extended.

[0075] The movable arms 432' have a plurality of portions 514 that may be detents and/or indents along the movable arm 432’. The portions 514 may be formed at specific positions along the arm 432’. The portions 514 may allow the arm 432’ to be positioned at a selected and known specific position relative to the body 328’. This allows portions of the arm 432’, such as the tracking portion 340, to be placed at specific positions from the center 350.

[0076] The DRF 140 may include an arm engaging member also referred to as a tab 516. The tab 516 may elastically or resiliently move to engage the portions 514 along the arm 432’ to retain the arm 432' in known positions relative to the body 328’. The tab 516 may act as a spring an engage the arm 432’ relative to one of the portions 514, such as extend inward into one of the indents, engage between detents, or any combinations thereof when at a selected positions relative to the portions 514. While the tab 516 may hold the arm 432’ in a selected position, however, the force of the tab 516 may be small enough so that position of the arm 432' may be changed by overcoming the force by a user who may wish to relocate the arm moveable 432’.

[0077] Similarly, the EM tracking portion 436 may be mounted or positioned on the body 328' at a known or selected mounting position 438. Therefore, the EM tracking portion 436 may be removably mounted to the body 328' at the selected position 438 for a selected tracking purpose. The movable arms 432' may also, therefore, move relative to the EM tracking portion 436. It is understood, however, that only one of the tracking modalities may be used at a time, such as the tracking portions 340 or the EM tracking portion 436, or they may be used simultaneously or sequentially. Regardless the EM tracking portion 436 may be mounted to the body 328’ in a manner similar to that discussed above.

[0078] With reference to FIG. 1 , the DRF 140 may be connected to the subject 28 at a selected time. For example, the DRF 140 may be connected to the subject 28 to assist in or define the fiducial points relative to the subject 28 during an imaging procedure. As illustrated in FIG. 1 , the DRF 140 may be positioned relative to the subject 28 and the subject 28 may be positioned relative to the imaging system 36. Image data may be acquired of the subject 28 and the DRF 140 including the fiducial portions 334. As discussed above, the fiducial portions 334 may be imageable in one or a plurality of imaging modalities. Further, the DRF 140 as an assembly may be compatible with one or more imaging modalities such as X-ray imaging, CT imaging, MRI imaging, or the like. This may allow the DRF 140 to be connected to the subject 28 to define or provide fiducial points for later registration, as discussed above and herein.

[0079] The arms 432 of the DRF 140 may be positioned into a selected or first position, such as a compact or retracted position or configuration. As illustrated in FIG. 1 , the movable arms 432 may be positioned in a retracted position to allow or assist for positioning the DRF 140 within an opening or image volume of the imaging system 36. Thus, the retractable or movable arms 432 made be positioned in the first position to assist in ensuring that the DRF 140 is properly imaged and associated with the subject of 28 during an imaging process.

[0080] During a navigation procedure, however, the arms may be moved to a different orientation or configuration. As discussed above, the movable arms 432 may be moved to one or more positions relative to the body 328 and the origin 350. The different configurations due to the independent and variable movement of the arms 432 may be identified by one or a plurality of navigation systems as a DRF. Thus, the determination of the DRF in the navigation space may be done substantially automatically by identifying the geometry of the trackable portions, such as the trackable portions 340 that are associated with the arms 432. Even if the arms 432 are positioned in more or different positions the tracking system may automatically identify the geometry of the tracked portions, such as the trackable portions 340, and identify the DRF 140 in the navigation space.

[0081] Further, the movable arms 432 do not change the position of the origin 350, even when they move. Thus, the position of the trackable portions 340 does not alter the pose of the origin 350 relative to the subject 28. The origin 350 also is not altered during the procedure after the imaging that was defined during the imaging by positioning the DRF 140 relative to the subject 28.

[0082] By allowing positioning of the movable arms 432 at a plurality of positions relative to the body 328, the geometry of the trackable portions 340 may be defined in a plurality of geometries. Each of the plurality of geometries may be identified by different tracking systems or navigation systems as a DRF. Further, the requirements of different navigation systems may require the tracking portions 340 to be positioned in different poses relative to the body 328 or the origin 350. Thus, the single DRF 140 may be positioned in a plurality of geometries such as in a retracted geometries as illustrated in FIG. 1 and FIG. 2, a partially expanded geometry is illustrated in FIG. 5A and 5B or in an entirely extended geometry as illustrated in FIG. 5C. Each of the different geometries may be identified by one or more navigation systems as DRF and the single DRF 140 may be used to achieve all of the different geometries. Thus, a plurality of DRFs are not necessary to be used with a plurality of different navigation systems, but the single DRF 140 may be used for use of a navigation of a plurality of procedures with one or more navigation systems or tracking systems.

[0083] As noted above, the dynamic reference frame 140 may be used to define the origin 350. The origin 350 may be defined relative to the fiducials 334. Further, as the origin 350 may be any defined point relative to the DRF 140 it may also be known relative to any known configuration of the arms 432, 432’. Thus, the arms 432, 432’ may be moved to the selected and known poses and the origin 350 may also be known relative thereto.

[0084] As discussed above, various tracking systems may be used to track a single one DRF 140. Each of a plurality of tracking systems may have a predetermined DRF configuration. Therefore, the single DRF 140 may be configurable to be a DRF in many different tracking systems. In various embodiments, each tracking system may track and identify a configuration of the DRF 140 and thereby track it as the DRF for the system and procedure. [0085] With reference to FIG. 6, a flowchart 600 for registering a patient space to an image space is illustrated. Initially, the procedure begins in start block 602. The procedure then proceeds to block 604 where a DRF 140 is immovably fixed to the patient 28, such as with the reference arm 310 and the extendable arms in the desired position. For example, the DRF 140 can be fixed to the patient with a clamp or screw as mentioned above. None or some of the extendable arms 432, 432’ may be extended.

[0086] Image data may be acquired of the subject 28 once the DRF 140 is associated, such as connected, to the subject 28 in block 605. This may allow the DRF 140 to be imaged with the subject 28. As discussed above, the DRF 140 may include one or more fiducial portions 334. The fiducial portions 334 may be imaged and appear in acquired or generated images, such as the image fiducial portions 334i. The DRF 140, therefore, may operate as a fiducial when maintained in the same position on the subject during imaging and during a registration.

[0087] The patient space can be registered to the image space in block 606. The registration uses the DRF 140 that defines an origin. Registration can proceed according to any appropriate registration procedure, including those discussed above. For example, the user 24 can identify, such as by touching with the instrument 144, various portions on the DRF 140 and touch or identify the same portions in the image 40 illustrated on the display device 44. It is understood that the image 40 can be any appropriate image, and vertebrae merely exemplary.

[0088] Additionally, or alternatively, the fiducial image portions 334i may be automatically identified in the image 40. The fiducial portions 334 in the DRF 140 may have a known geometry relative to one another and to the origin 350. The fiducial portions 334i in the image 40 may be identified in an appropriate manner such as automatically by image analysis, identification by the user 24, or other appropriate or combinations thereof. For example, the processor 56 may perform an image analysis for selected shapes, geometries, contrast, or the like to identify the fiducial image portions 334i. Once the image fiducial portions 334i are identified in the image 40, the navigation processor may then correlate them to the fiducial portions 334 in the DRF 140.

[0089] The fiducials on or in the DRF 140 may be identified in the navigation space by touching them by the user 24 with a tracked instrument. The user moving a tracked instrument to touch one or more of the divots in the DRF 140 that have know special poses relative to the fiducials. Additionally or alternatively, the fiducials may have their poses determined in navigation space by tracking the tracking portions 340 and/or the EM tracking 436. As discussed above, the tracking portions on the arms 432 may be moved to selected and known poses and the EM tracking portions 436 may be placed at a known mounting pose 438. Thus, the poses of the fiducials relative to tracked portions may also be known.

[0090] Once correlated the known position of the fiducial portions 334 relative to the origin 350 and the identified image fiducial portions 334i may also be determined relative to an origin in the image 40 to allow for a mapping of the fiducial portions 334i in the image 40 to the fiducial portions 334 in the DRF 140. This mapping allows a registration of the subject space defined relative to the DRF 140 and the image space defined by the image 40. The tracking system 50 may then track the position of various portions, such as the instrument 140 relative to the DRF 140 and illustrate the same in the image, such as with the graphic representation 180. In other words, once the registration has occurred, the patient space defined by the tracking system 50, including any appropriate tracking modality (e.g., EM, optical, etc.), relative to the patient 28 is registered to the image 40. Accordingly, the points defined by the image 40 are correlated or registered to points of the image 40 which are relative to the origin. The registration allows for the tracking system 50 to track the instrument 144, transmit a tracking signal to the navigation system 20, and the navigation system 20 may then illustrate the tracked location, including position and orientation of the instrument 144, superimposed on the image 40 as shown by graphical representation 180. It is understood that processing, including executing of various program instructions, can be performed by a single processor for all of the tracking system, navigation system, imaging system, etc. Thus, the user 24 can view the display device 44 and understand the position of the instrument 144 relative to the patient 28 by viewing the graphical representation 180 displayed relative to, such as superimposed on, the image 40 on the display device 44 that represents the location of the instrument 144 relative to the patient 28. Thus, the instrument 144 can be navigated relative to the subject 26 with the registered image space in block 608. It is understood, however, that initial navigation is optional and need not occur for the remaining process of the flowchart 600 to occur.

[0091] The registration can be maintained although the movable arms

432, 432’ of the DRF 140 move relative to the body 328, 328’. The registration allows tracking of the instrument 144 or other tracked portion to be maintained and illustrated on the display 22. Thus, only a single registration may be needed although the DRF 140 has changed configuration. The tracking system 50 can track movement of the DRF 140 to maintain the registration even though the patient moves relative to the localizer 130, 138. Accordingly, movement of the patient 28 can be allowed during a procedure while maintaining registration and not requiring re-registration of the patient 28 to the image space of the image 40.

[0092] As discussed above, the origin 350 of the DRF 140 may be determined. The origin 350 may be an identified point in the navigation space that is defined relative to the subject 28 for a procedure. Navigation of instruments may be made and determined relative to the origin 350. The origin 350 may be determined as a part of the DRF 140 that is generally immovable, regardless of whether the immovable arm 432, 432’ moves relative to the origin 350 or other portions of the body 328, 328'. Thus, the determination of the origin in block 607 may be included as a part of the registration or identified thereafter. Thus, movements of any portion of the DRF 140, such as one or more of the movable arms 432, 432' may allow for the maintaining of the determined origin 350 of the DRF 140.

[0093] During a procedure, the DRF and/or portions thereof, such as the movable arm 432, 432’, can be determined to be in an undesired position relative to the patient 28 for performing a procedure. For example, during a spinal fusion the movable arm 432, 432’ may obstruct a view or a movement of the instrument 144 for performing a procedure. Thus, the user 24 can determine or select to move the movable arm 432. Once it is determined to move at least one of the arms 432, 432’, the one or more arms 432, 432’ can be moved into another position in block 610 while maintaining a fixed connection to the patient.

[0094] As the origin 350 is maintained in the second pose relative to the subject 28, an adjustment factor for a registration is not required as the origin 350 is not moved. Thus, the arm 432 may be moved relative to the body 328 without changing a registration, which is a mapping of a pose of the DRF 140 that defines the navigation space relative to the image space defined by the image 40. The various portions, such as the movable arms 432 may assist in maintaining the determination of the origin 350 by moving in a plane that is the same or parallel to a plane of the body 328. Thus, all of the trackable portions 340 may be maintained in a substantially planar position and orientation and the pose of the origin 350 may therefore be maintained.

[0095] Further, the position of the trackable portions, such as the optical trackable portions 340 may be put at known positions relative to one another due to the various stops or portions of the arms 432, 432' as discussed above. For example, the portions 514 may assist in ensuring that the arms 432 are positioned at known positions relative to the body 328, 328’ and the origin 350. This allows the geometry of the DRF 140 to be known and predetermined, even if it changes between different configurations due to movement of the arms 432, 432'. The registration in block 612 may be maintained and continuation of navigation of the instrument 144 can occur on block 614 without adjustment to the registration or translation map. Accordingly, navigation of the instrument 144 can continue, although one of more of the movable arms has moved from the first position to the second position. In particular, the registration performed in block 606 is not altered due to movement of movable arms 432, 432.’ This is due, at least in part, to the identification of the origin 350 during the initial registration of the navigation space to the image space. In various embodiment, this is due to the identification of the origin and also the determination of the orientation (i.e. vectorial bearing/alignment) of the reference frame from the initial registration.

[0096] The navigation of the instrument 144 can continue with illustration of the navigated instrument superimposed on the image in block 616. The display device 44 can display the graphical representation 180 representing the instrument 144 superimposed on the image 40. The position of the instrument 144 can include an illustration of the entire instrument, an attachment or implant associated with instrument 144, or any appropriate illustration. For example, a line can be used to illustrate a central longitudinal axis of the instrument 144 without illustrating details of the instrument 144. Alternatively, or in addition thereto, a model of the instrument 144 can be superimposed on the image 40 to display substantially all of the instrument 144. Thereafter, the procedure can end at block 618. It is understood, however, that the method in flowchart 600 describes the positioning, registration, and movement of the movable arms 432, 432’ relative to the patient 28 and does not describe and entire procedure, such as performing or completion of a procedure. Accordingly, the flowchart 600 illustrates the procedure or method of maintaining registration during movement or after movement of a reference arm of a DRF.

[0097] The DRF can be associated with a patient 28 with the movable arms 432, 432’ in a first position. By way of example, some imaging volumes of an imaging device are small and therefore arms 432, 432’ may be retracted. Thereafter, the movable arms 432, 432’ move to the second position in block 610. For example, one or more of the moveable arms 432, 432’ can be extended and the registration can be maintained during, for example, navigation. Thus, a procedure can be performed efficiently without requiring a reregistration of the patient relative to the image 40. This can reduce the time of a procedure and ensure proper navigation of the instrument 144. By allowing registration to occur at a single time, and registration to be maintained although the DRF arms have moved, the procedure need not stop or be slowed to re-register. Thus, a procedure can be performed in less time to allow for various benefits of the patient such as a reduced operating time, reduced or minimized anesthesia time and other various operative benefits. Further, additional image data need not be acquired of the patient 28 when a DRF arm position has been altered to perform a second registration. By decreasing the amount of image data required, which may require ionization radiation, the subject can have limited exposure to the radiation. The known or determined position or orientation of the reference arm at the second arm relative to the first position can be used to determine the adjustment factor to retain the original registration for continuing the navigation.

[0098] Further, the arms 432, 43’ may move in any appropriate manner. In various examples, the arms 432, 432’ may move in a curve. In various embodiments, the curve may still maintain the trackable portions in a plane that is the same or parallel to the body 328. The arms 432, 432’ may also be provided in multiple lengths in a single DRF 140 assembly. Moreover, as noted above, not all of the arms 432, 432’ need move in a single DRF 140.

[0099] In various embodiments, the frame or DRF configuration can be changed during a procedure without changing a registration or translation map, e.g., the origin is maintained. The DRF may be put in a selected configuration that may be an optimal configuration for each step or portion of a procedure. For example, the DRF may be fully expanded during registration to get a selected registration, which may be a best possible registration due to the area or volume covered by the DRF. Then, the DRF may be fully collapsed during navigation near the frame so that it is out of the way. Then the DRF may be fully expanded again when navigating far from the frame so that accuracy is preserved over the larger distance.

[00100] Examples

[00101] Example 1 . A reference frame for guided surgery comprising: a body comprising a central portion; at least one arm that is moveable relative to the body; and at least one of:

(1) a mounting position for an electromagnetic tracking device;

(2) a plurality of fiducial markers corresponding to at least one of a first imaging modality or a second imaging modality; or

(3) an optical tracking device disposed on the first end of the at least one arm.

[00102] Example 2. The reference frame of claim 1 wherein the at least one arm is coupled to an exterior surface of the body.

[00103] Example 3. The reference frame of claim 1 wherein a second end of the at least one arm is retained within a channel formed within the body.

[00104] Example 4. The reference frame of claim 3 wherein the body comprises a tab configured to engage a portion of the at least one arm to hold the at least one arm in a selected position relative to the body.

[00105] Example 5. The reference frame of claim 4 wherein the portion includes a plurality of portions of the at least one arm.

[00106] Example 6. The reference frame of claim 1 wherein the fiducial markers comprise x-ray imageable fiducial markers.

[00107] Example 7. The reference frame of Example wherein the fiducial markers comprise MRI imageable fiducial markers.

[00108] Example 8. The reference frame of Example 1 wherein the at least one arm includes a plurality of arms; wherein at least a sub-plurality of the plurality of arms are operable to move relative to the body.

[00109] Example 9. The reference frame of claim 8 wherein the optical tracking device includes a plurality of optical tracking devices; wherein each arm of the plurality of arms has at least one optical tracking device disposed thereon at the first end of the arm.

[00110] Example 10. A method of using a navigation system comprising: fixing a configurable reference frame to a patient, the configurable reference frame comprising at least one arm moveable relative to a body and fiducial markers associated with the body; acquiring image data from imaging the patient with the configurable reference frame with the extendable arm in a first position; determining an origin pose of the configurable reference frame in a navigation space to an image space defined by the image data based on the fiducial markers; moving the arm from a first position to second position to form a selected configuration; and maintaining, or calculating, or inferring the origin pose after moving the extendable arm.

[00111] Example 11 . The method of Example 10 wherein the acquired image data comprises x-ray image data and providing x-ray imageable fiducials, the acquired image data comprises MRI image data and providing MRI imageable fiducials, or combinations thereof.

[00112] Example 12. The method of Example 10 further comprising: performing a navigation guided procedure by tracking at least one optical tracking marker disposed on the at least one of the arms in the second position.

[00113] Example 13. The method of Example 10 further comprising: performing a navigation guided procedure by tracking an EM tracking marker coupled to the body.

[00114] Example 14. The method of Example 10 Wherein moving the extendable arm comprises moving the extendable arm in a channel within the body.

[00115] Example 15. A method of using a navigation system comprising: providing a reference frame with a body comprising a central portion and at least one arm that is moveable relative to the body, a mounting position for an electromagnetic tracking device, a plurality of fiducial markers corresponding to a first imaging modality and a second imaging modality, an optical tracking device disposed on the first end of the at least one arm; associating the reference frame with a subject; and acquiring image data of the subject and the reference frame including image fiducial portions based on the fiducial markers.

[00116] Example 16. The method of Example 15 further comprising: determining a selected navigation system; recalling a reference configuration; and providing the reference frame with the arm in the reference configuration.

[00117] Example 17. The method of Example 16 further comprising: moving the arm to the reference configuration.

[00118] Example 18. The method of Example 17 further comprising: determining an origin defined by the reference frame based at least on the providing reference configuration.

[00119] Example 19. The method of Example 18 further comprising: registering the image data to a navigation space defined by the reference frame due to a mapping of the fiducial markers in the reference frame to image fiducial portions.

[00120] Example 20. The method of Example 15 further comprising: selecting a configuration of the reference frame based on a portion of a procedure.

[00121] 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.

[00122] 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.

[00123] 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.

[00124] 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®.

[00125] 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 802.11ad, and/or draft IEEE standard 802.11 ah.

[00126] 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.

[00127] 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.

[00128] 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.

Claims

CLAIMS What is claimed is:

1 . A reference frame for guided surgery comprising: a body comprising a central portion; at least one arm that is moveable relative to the body; and at least one of:

(1 ) a mounting position for an electromagnetic tracking device;

2. The reference frame of claim 1 wherein the at least one arm is coupled to an exterior surface of the body.

3. The reference frame of claim 1 wherein a second end of the at least one arm is retained within a channel formed within the body.

4. The reference frame of claim 3 wherein the body comprises a tab configured to engage a portion of the at least one arm to hold the at least one arm in a selected position relative to the body.

5. The reference frame of claim 4 wherein the portion includes a plurality of portions of the at least one arm.

6. The reference frame of claim 1 wherein the fiducial markers comprise x-ray imageable fiducial markers or MRI imageable fiducial markers or both.

7. The reference frame of claim 1 wherein the at least one arm includes a plurality of arms; wherein at least a sub-plurality of the plurality of arms are operable to move relative to the body.

8. The reference frame of claim 7 wherein the optical tracking device includes a plurality of optical tracking devices; wherein each arm of the plurality of arms has at least one optical tracking device disposed thereon at the first end of the arm.

9. A method of using a navigation system comprising: fixing a configurable reference frame to a patient, the configurable reference frame comprising at least one arm moveable relative to a body and fiducial markers associated with the body; acquiring image data from imaging the patient with the configurable reference frame with the extendable arm in a first position; determining an origin pose of the configurable reference frame in a navigation space to an image space defined by the image data based on the fiducial markers; moving the arm from a first position to second position to form a selected configuration; and maintaining, or calculating, or inferring the origin pose after moving the extendable arm.

10. A method of using a navigation system comprising: providing a reference frame with a body comprising a central portion and at least one arm that is moveable relative to the body, a mounting position for an electromagnetic tracking device, a plurality of fiducial markers corresponding to a first imaging modality and a second imaging modality, an optical tracking device disposed on the first end of the at least one arm; associating the reference frame with a subject; and acquiring image data of the subject and the reference frame including image fiducial portions based on the fiducial markers.

11 . The method of Claim 10 further comprising: determining a selected navigation system; recalling a reference configuration; and providing the reference frame with the arm in the reference configuration.

12. The method of Claim 11 further comprising: moving the arm to the reference configuration.

13. The method of Claim 12 further comprising: determining an origin defined by the reference frame based at least on the providing reference configuration.

14. The method of Claim 13 further comprising: registering the image data to a navigation space defined by the reference frame due to a mapping of the fiducial markers in the reference frame to image fiducial portions.

15. The method of Claim 10 further comprising: selecting a configuration of the reference frame based on a portion of a procedure.