Patent Publication Number: US-2021169581-A1

Title: Extended reality instrument interaction zone for navigated robotic surgery

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/709,185 filed on Dec. 10, 2019, which is incorporated in it&#39;s entirety herein. 
    
    
     FIELD 
     The present disclosure relates to medical devices and systems, and more particularly, computer assisted navigation in surgery using robotic surgical systems. 
     BACKGROUND 
     Computer assisted navigation in surgery provides surgeons with enhanced visualization of surgical instruments with respect to radiographic images of the patient&#39;s anatomy. Navigated surgeries typically include components for tracking the position and orientation of surgical instruments via arrays of disks or spheres using a single near infrared (NIR) stereo camera setup. In this scenario, there are three parameters jointly competing for optimization: (1) accuracy, (2) robustness and (3) ergonomics. 
     Navigated surgery procedures using existing navigation systems are prone to events triggering intermittent pauses while personnel and/or objects obstruct the ability of a tracking component to track poses of the patient, the robot, and surgical instruments. There is a need to improve the tracking performance of navigation systems. 
     SUMMARY 
     Various embodiments disclosed herein are directed to improvements in computer assisted navigation during surgery. One or more extended reality (“XR”) headsets can be equipped with tracking cameras that provide tracking information to a camera tracking system for combining with tracking information from other tracking cameras which may be part of another XR headset, an auxiliary tracking bar, or other equipment. Through various pose chaining operations disclosed herein the camera tracking system may be able to track tools and other objects with greater robustness and through a wide range of motion. 
     In one embodiment, a surgical system includes an extended reality (“XR”) headset configured to be worn during a surgical procedure, a tracking system, and an XR headset controller. The XR headset includes a see-through display screen configured to display a world-registered XR image and to allow at least a portion of a real-world scene to pass therethrough for viewing by the user. The tracking system is configured to determine a real-world pose of the XR headset and a real-world pose of a real-world element. The real-world pose of the XR headset and the real-world pose of the real-world element are determined relative to a real-world coordinate system. The XR headset controller is configured to generate the world-registered XR image based on the real-world pose of the XR headset and the real-world pose of the real-world element. The world-registered XR image includes a virtual element that is generated based on a characteristic of the real-world element. 
     Related methods by surgical system a related robotic surgical system are disclosed. 
     Other surgical systems, method, and computer program products according to embodiments will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such surgical systems, method, and computer program products be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. Moreover, it is intended that all embodiments disclosed herein can be implemented separately or combined in any way and/or combination. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in a constitute a part of this application, illustrate certain non-limiting embodiments of inventive concepts. In the drawings: 
         FIG. 1  illustrates an embodiment of a surgical system according to some embodiments of the present disclosure; 
         FIG. 2  illustrates a surgical robot component of the surgical system of  FIG. 1  according to some embodiments of the present disclosure; 
         FIG. 3A  illustrates a camera tracking system component of the surgical system of  FIG. 1  according to some embodiments of the present disclosure; 
         FIGS. 3B and 3C  illustrate a front view and isometric view of another camera tracking system component which may be used with the surgical system of  FIG. 1  according to some embodiments of the present disclosure; 
         FIG. 4  illustrates an embodiment of an end effector that is connectable to a robot arm and configured according to some embodiments of the present disclosure; 
         FIG. 5  illustrates a medical operation in which a surgical robot and a camera system are disposed around a patient; 
         FIG. 6  illustrates a block diagram view of the components of the surgical system of  FIG. 5  being used for a medical operation; 
         FIG. 7  illustrates various display screens that may be displayed on the display of  FIGS. 5 and 6  when using a navigation function of the surgical system; 
         FIG. 8  illustrates a block diagram of some electrical components of a surgical robot according to some embodiments of the present disclosure; 
         FIG. 9  illustrates a block diagram of components of a surgical system that includes imaging devices connected to a computer platform which can be operationally connected to a camera tracking system and/or surgical robot according to some embodiments of the present disclosure; 
         FIG. 10  illustrates an embodiment of a C-Arm imaging device that can be used in combination with the surgical robot in accordance with some embodiments of the present disclosure; 
         FIG. 11  illustrates an embodiment of an O-Arm imaging device that can be used in combination with the surgical robot in accordance with some embodiments of the present disclosure; 
         FIG. 12  illustrates a block diagram view of the components of a surgical system that includes a pair of XR headsets and an auxiliary tracking bar which operate in accordance with some embodiments of the present disclosure; 
         FIG. 13  illustrates an XR headset which is configured in accordance with some embodiments of the present disclosure; 
         FIG. 14  illustrates electrical components of the XR headset that can be operatively connected to a computer platform, imaging device(s), and/or a surgical robot in accordance with some embodiments of the present disclosure; 
         FIG. 15  illustrates a block diagram showing arrangement of optical components of the XR headset in accordance with some embodiments of the present disclosure; 
         FIG. 16  illustrates an example view through the display screen of an XR headset for providing navigation assistance to manipulate a surgical tool during a medical procedure in accordance with some embodiments of the present disclosure; 
         FIG. 17  illustrates an example configuration of an auxiliary tracking bar having two pairs of stereo cameras configured in accordance with some embodiments of the present disclosure; 
         FIGS. 18-22  illustrate examples of errors introduced during navigation assistance of a surgical tool used in a medical procedure in accordance with some embodiments of the present disclosure; 
         FIG. 23  illustrates an example of medical procedure using navigation assistance in accordance with some embodiments of the present disclosure; and 
         FIGS. 24-32  illustrate examples of manipulating the navigation assistance of  FIG. 37  in accordance with some embodiments of the present disclosure. 
         FIG. 33  illustrates a block diagram of an example of a surgical system in accordance with some embodiments of the present disclosure. 
         FIG. 34  illustrates a flowchart that is an example of a process performed by a surgical system in accordance with some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Inventive concepts will now be described more fully hereinafter with reference to the accompanying drawings, in which examples of embodiments of inventive concepts are shown. Inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of various present inventive concepts to those skilled in the art. It should also be noted that these embodiments are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present or used in another embodiment. 
     Various embodiments disclosed herein are directed to improvements in computer assisted navigation during surgery. An extended reality (XR) headset is operatively connected to the surgical system and configured to provide an interactive environment through which a surgeon, assistant, and/or other personnel can view and select among patient images, view and select among computer generated surgery navigation information, and/or control surgical equipment in the operating room. As will be explained below, the XR headset may be configured to augment a real-world scene with computer generated XR images. The XR headset may be configured to provide an augmented reality (AR) viewing environment by displaying the computer generated XR images on a see-through display screen that allows light from the real-world scene to pass therethrough for combined viewing by the user. Alternatively, the XR headset may be configured to provide a virtual reality (VR) viewing environment by preventing or substantially preventing light from the real-world scene from being directly viewed by the user while the user is viewing the computer generated AR images on a display screen. An XR headset can be configured to provide both AR and VR viewing environments. In one embodiment, both AR and VR viewing environments are provided by lateral bands of substantially differing opacity arranged between the see-through display screen and the real-world scene, so that a VR viewing environment is provided for XR images aligned with a high opacity band and an AR viewing environment is provided for XR images aligned with the low opacity band. In another embodiment, both AR and VR viewing environments are provided by computer adjustable control of an opacity filter that variably constrains how much light from the real-world scene passes through a see-through display screen for combining with the XR images viewed by the user. Thus, the XR headset can also be referred to as an AR headset or a VR headset. 
       FIG. 1  illustrates an embodiment of a surgical system  2  according to some embodiments of the present disclosure. Prior to performance of an orthopedic or other surgical procedure, a three-dimensional (“3D”) image scan may be taken of a planned surgical area of a patient using, e.g., the C-Arm imaging device  104  of  FIG. 10  or O-Arm imaging device  106  of  FIG. 11 , or from another medical imaging device such as a computed tomography (CT) image or Mill. This scan can be taken pre-operatively (e.g. few weeks before procedure, most common) or intra-operatively. However, any known 3D or 2D image scan may be used in accordance with various embodiments of the surgical system  2 . The image scan is sent to a computer platform in communication with the surgical system  2 , such as the computer platform  910  of the surgical system  900  ( FIG. 9 ) which may include the camera tracking system component  6 , the surgical robot  4  (e.g., robot  2  in  FIG. 1 ), imaging devices (e.g., C-Arm  104 , O-Arm  106 , etc.), and an image database  950  for storing image scans of patients. A surgeon reviewing the image scan(s) on a display device of the computer platform  910  ( FIG. 9 ) generates a surgical plan defining a target pose for a surgical tool to be used during a surgical procedure on an anatomical structure of the patient. Example surgical tools, also referred to as tools, can include, without limitation, drills, screw drivers, retractors, and implants such as a screws, spacers, interbody fusion devices, plates, rods, etc. In some embodiments, the surgical plan defining the target plane is planned on the 3D image scan displayed on a display device. 
     As used herein, the term “pose” refers to the position and/or the rotational angle of one object (e.g., dynamic reference array, end effector, surgical tool, anatomical structure, etc.) relative to another object and/or to a defined coordinate system. A pose may therefore be defined based on only the multidimensional position of one object relative to another object and/or to a defined coordinate system, only on the multidimensional rotational angles of the object relative to another object and/or to a defined coordinate system, or on a combination of the multidimensional position and the multidimensional rotational angles. The term “pose” therefore is used to refer to position, rotational angle, or combination thereof. 
     The surgical system  2  of  FIG. 1  can assist surgeons during medical procedures by, for example, holding tools, aligning tools, using tools, guiding tools, and/or positioning tools for use. In some embodiments, surgical system  2  includes a surgical robot  4  and a camera tracking system component  6 . The ability to mechanically couple surgical robot  4  and camera tracking system component  6  can allow for surgical system  2  to maneuver and move as a single unit, and allow surgical system  2  to have a small footprint in an area, allow easier movement through narrow passages and around turns, and allow storage within a smaller area. 
     A surgical procedure may begin with the surgical system  2  moving from medical storage to a medical procedure room. The surgical system  2  may be maneuvered through doorways, halls, and elevators to reach a medical procedure room. Within the room, the surgical system  2  may be physically separated into two separate and distinct systems, the surgical robot  4  and the camera tracking system component  6 . Surgical robot  4  may be positioned adjacent the patient at any suitable location to properly assist medical personnel. Camera tracking system component  6  may be positioned at the base of the patient, at the patient shoulders, or any other location suitable to track the present pose and movement of the pose of tracks portions of the surgical robot  4  and the patient. Surgical robot  4  and camera tracking system component  6  may be powered by an onboard power source and/or plugged into an external wall outlet. 
     Surgical robot  4  may be used to assist a surgeon by holding and/or using tools during a medical procedure. To properly utilize and hold tools, surgical robot  4  may rely on a plurality of motors, computers, and/or actuators to function properly. Illustrated in  FIG. 1 , robot body  8  may act as the structure in which the plurality of motors, computers, and/or actuators may be secured within surgical robot  4 . Robot body  8  may also provide support for robot telescoping support arm  16 . The size of robot body  8  may provide a solid platform supporting attached components, and may house, conceal, and protect the plurality of motors, computers, and/or actuators that may operate attached components. 
     Robot base  10  may act as a lower support for surgical robot  4 . In some embodiments, robot base  10  may support robot body  8  and may attach robot body  8  to a plurality of powered wheels  12 . This attachment to wheels may allow robot body  8  to move in space efficiently. Robot base  10  may run the length and width of robot body  8 . Robot base  10  may be about two inches to about 10 inches tall. Robot base  10  may cover, protect, and support powered wheels  12 . 
     In some embodiments, as illustrated in  FIG. 1 , at least one powered wheel  12  may be attached to robot base  10 . Powered wheels  12  may attach to robot base  10  at any location. Each individual powered wheel  12  may rotate about a vertical axis in any direction. A motor may be disposed above, within, or adjacent to powered wheel  12 . This motor may allow for surgical system  2  to maneuver into any location and stabilize and/or level surgical system  2 . A rod, located within or adjacent to powered wheel  12 , may be pressed into a surface by the motor. The rod, not pictured, may be made of any suitable metal to lift surgical system  2 . The rod may lift powered wheel  10 , which may lift surgical system  2 , to any height required to level or otherwise fix the orientation of the surgical system  2  in relation to a patient. The weight of surgical system  2 , supported through small contact areas by the rod on each wheel, prevents surgical system  2  from moving during a medical procedure. This rigid positioning may prevent objects and/or people from moving surgical system  2  by accident. 
     Moving surgical system  2  may be facilitated using robot railing  14 . Robot railing  14  provides a person with the ability to move surgical system  2  without grasping robot body  8 . As illustrated in  FIG. 1 , robot railing  14  may run the length of robot body  8 , shorter than robot body  8 , and/or may run longer the length of robot body  8 . Robot railing  14  may further provide protection to robot body  8 , preventing objects and or personnel from touching, hitting, or bumping into robot body  8 . 
     Robot body  8  may provide support for a Selective Compliance Articulated Robot Arm, hereafter referred to as a “SCARA.” A SCARA  24  may be beneficial to use within the surgical system  2  due to the repeatability and compactness of the robotic arm. The compactness of a SCARA may provide additional space within a medical procedure, which may allow medical professionals to perform medical procedures free of excess clutter and confining areas. SCARA  24  may comprise robot telescoping support  16 , robot support arm  18 , and/or robot arm  20 . Robot telescoping support  16  may be disposed along robot body  8 . As illustrated in  FIG. 1 , robot telescoping support  16  may provide support for the SCARA  24  and display  34 . In some embodiments, robot telescoping support  16  may extend and contract in a vertical direction. The body of robot telescoping support  16  may be any width and/or height configured to support the stress and weight placed upon it. 
     In some embodiments, medical personnel may move SCARA  24  through a command submitted by the medical personnel. The command may originate from input received on display  34 , a tablet, and/or an XR headset (e.g., headset  920  in  FIG. 9 ) as will be explained in further detail below. The XR headset may eliminate the need for medical personnel to refer to any other display such as the display  34  or a tablet, which enables the SCARA  24  to be configured without the display  34  and/or the tablet. The command may be generated by the depression of a switch and/or the depression of a plurality of switches, and/or may be generated based on a hand gesture command and/or voice command that is sensed by the XR headset as will be explained in further detail below. 
     As shown in  FIG. 5 , an activation assembly  60  may include a switch and/or a plurality of switches. The activation assembly  60  may be operable to transmit a move command to the SCARA  24  allowing an operator to manually manipulate the SCARA  24 . When the switch, or plurality of switches, is depressed the medical personnel may have the ability to move SCARA  24  through applied hand movements. Alternatively or additionally, an operator may control movement of the SCARA  24  through hand gesture commands and/or voice commands that are sensed by the XR headset as will be explained in further detail below. Additionally, when the SCARA  24  is not receiving a command to move, the SCARA  24  may lock in place to prevent accidental movement by personnel and/or other objects. By locking in place, the SCARA  24  provides a solid platform through which the end effector  26  can guide a surgical tool during a medical procedure. 
     Robot support arm  18  can be connected to robot telescoping support  16  by various mechanisms. In some embodiments, best seen in  FIGS. 1 and 2 , robot support arm  18  rotates in any direction in regard to robot telescoping support  16 . Robot support arm  18  may rotate three hundred and sixty degrees around robot telescoping support  16 . Robot arm  20  may connect to robot support arm  18  at any suitable location and by various mechanisms that enable rotation in any direction relative to robot support arm  18 . In one embodiment, the robot arm  20  can rotate three hundred and sixty degrees relative to the robot support arm  18 . This free rotation allows an operator to position robot arm  20  according to a surgical plan. 
     The end effector  26  shown in  FIGS. 4 and 5  may attach to robot arm  20  in any suitable location. The end effector  26  can be configured to attach to an end effector coupler  22  of the robot arm  20  positioned by the surgical robot  4 . The example end effector  26  includes a tubular guide that guides movement of an inserted surgical tool relative to an anatomical structure on which a surgical procedure is to be performed. 
     In some embodiments, a dynamic reference array  52  is attached to the end effector  26 . Dynamic reference arrays, also referred to as “DRAs” herein, are rigid bodies which may be disposed on an anatomical structure (e.g., bone) of a patient, one or more XR headsets being worn by personnel in the operating room, the end effector, the surgical robot, a surgical tool in a navigated surgical procedure. The computer platform  910  in combination with the camera tracking system component  6  or other 3D localization system are configured to track in real-time the pose (e.g., positions and rotational orientations) of the DRA. The DRA can include fiducials, such as the illustrated arrangement of balls. This tracking of 3D coordinates of the DRA can allow the surgical system  2  to determine the pose of the DRA in any multidimensional space in relation to the target anatomical structure of the patient  50  in  FIG. 5 . 
     As illustrated in  FIG. 1 , a light indicator  28  may be positioned on top of the SCARA  24 . Light indicator  28  may illuminate as any type of light to indicate “conditions” in which surgical system  2  is currently operating. In some embodiments, the light may be produced by LED bulbs, which may form a ring around light indicator  28 . Light indicator  28  may comprise a fully permeable material that can let light shine through the entirety of light indicator  28 . Light indicator  28  may be attached to lower display support  30 . Lower display support  30 , as illustrated in  FIG. 2  may allow an operator to maneuver display  34  to any suitable location. Lower display support  30  may attach to light indicator  28  by any suitable mechanism. In some embodiments, lower display support  30  may rotate about light indicator  28  or be rigidly attached thereto. Upper display support  32  may attach to lower display support  30  by any suitable mechanism. 
     In some embodiments, a tablet may be used in conjunction with display  34  and/or without display  34 . The tablet may be disposed on upper display support  32 , in place of display  34 , and may be removable from upper display support  32  during a medical operation. In addition the tablet may communicate with display  34 . The tablet may be able to connect to surgical robot  4  by any suitable wireless and/or wired connection. In some embodiments, the tablet may be able to program and/or control surgical system  2  during a medical operation. When controlling surgical system  2  with the tablet, all input and output commands may be duplicated on display  34 . The use of a tablet may allow an operator to manipulate surgical robot  4  without having to move around patient  50  and/or to surgical robot  4 . 
     As will be explained below, in some embodiments a surgeon and/or other personnel can wear XR headsets that may be used in conjunction with display  34  and/or a tablet or the XR head(s) may eliminate the need for use of the display  34  and/or tablet. 
     As illustrated in  FIGS. 3A and 5 , camera tracking system component  6  works in conjunction with surgical robot  4  through wired or wireless communication networks. Referring to  FIGS. 1, 3 and 5 , camera tracking system component  6  can include some similar components to the surgical robot  4 . For example, camera body  36  may provide the functionality found in robot body  8 . Robot body  8  may provide an auxiliary tracking bar upon which cameras  46  are mounted. The structure within robot body  8  may also provide support for the electronics, communication devices, and power supplies used to operate camera tracking system component  6 . Camera body  36  may be made of the same material as robot body  8 . Camera tracking system component  6  may communicate directly to an XR headset, tablet and/or display  34  by a wireless and/or wired network to enable the XR headset, tablet and/or display  34  to control the functions of camera tracking system component  6 . 
     Camera body  36  is supported by camera base  38 . Camera base  38  may function as robot base  10 . In the embodiment of  FIG. 1 , camera base  38  may be wider than robot base  10 . The width of camera base  38  may allow for camera tracking system component  6  to connect with surgical robot  4 . As illustrated in  FIG. 1 , the width of camera base  38  may be large enough to fit outside robot base  10 . When camera tracking system component  6  and surgical robot  4  are connected, the additional width of camera base  38  may allow surgical system  2  additional maneuverability and support for surgical system  2 . 
     As with robot base  10 , a plurality of powered wheels  12  may attach to camera base  38 . Powered wheel  12  may allow camera tracking system component  6  to stabilize and level or set fixed orientation in regards to patient  50 , similar to the operation of robot base  10  and powered wheels  12 . This stabilization may prevent camera tracking system component  6  from moving during a medical procedure and may keep cameras  46  on the auxiliary tracking bar from losing track of a DRA connected to an XR headset and/or the surgical robot  4 , and/or losing track of one or more DRAs  52  connected to an anatomical structure  54  and/or tool  58  within a designated area  56  as shown in  FIGS. 3A and 5 . This stability and maintenance of tracking enhances the ability of surgical robot  4  to operate effectively with camera tracking system component  6 . Additionally, the wide camera base  38  may provide additional support to camera tracking system component  6 . Specifically, a wide camera base  38  may prevent camera tracking system component  6  from tipping over when cameras  46  is disposed over a patient, as illustrated in  FIGS. 3A and 5 . 
     Camera telescoping support  40  may support cameras  46  on the auxiliary tracking bar. In some embodiments, telescoping support  40  moves cameras  46  higher or lower in the vertical direction. Camera handle  48  may be attached to camera telescoping support  40  at any suitable location and configured to allow an operator to move camera tracking system component  6  into a planned position before a medical operation. In some embodiments, camera handle  48  is used to lower and raise camera telescoping support  40 . Camera handle  48  may perform the raising and lowering of camera telescoping support  40  through the depression of a button, switch, lever, and/or any combination thereof. 
     Lower camera support arm  42  may attach to camera telescoping support  40  at any suitable location, in embodiments, as illustrated in  FIG. 1 , lower camera support arm  42  may rotate three hundred and sixty degrees around telescoping support  40 . This free rotation may allow an operator to position cameras  46  in any suitable location. Lower camera support arm  42  may connect to telescoping support  40  by any suitable mechanism. Lower camera support arm  42  may be used to provide support for cameras  46 . Cameras  46  may be attached to lower camera support arm  42  by any suitable mechanism. Cameras  46  may pivot in any direction at the attachment area between cameras  46  and lower camera support arm  42 . In embodiments a curved rail  44  may be disposed on lower camera support arm  42 . 
     Curved rail  44  may be disposed at any suitable location on lower camera support arm  42 . As illustrated in  FIG. 3A , curved rail  44  may attach to lower camera support arm  42  by any suitable mechanism. Curved rail  44  may be of any suitable shape, a suitable shape may be a crescent, circular, oval, elliptical, and/or any combination thereof. Cameras  46  may be moveably disposed along curved rail  44 . Cameras  46  may attach to curved rail  44  by, for example, rollers, brackets, braces, motors, and/or any combination thereof. Motors and rollers, not illustrated, may be used to move cameras  46  along curved rail  44 . As illustrated in  FIG. 3A , during a medical procedure, if an object prevents cameras  46  from viewing one or more DRAs being tracked, the motors may responsively move cameras  46  along curved rail  44 . This motorized movement may allow cameras  46  to move to a new position that is no longer obstructed by the object without moving camera tracking system component  6 . While cameras  46  is obstructed from viewing one or more tracked DRAs, camera tracking system component  6  may send a stop signal to a surgical robot  4 , XR headset, display  34 , and/or a tablet. The stop signal may prevent SCARA  24  from moving until cameras  46  has reacquired tracked DRAs  52  and/or can warn an operator wearing the XR headset and/or viewing the display  34  and/or the tablet. This SCARA  24  can be configured to respond to receipt of a stop signal by stopping further movement of the base and/or end effector coupler  22  until the camera tracking system can resume tracking of DRAs. 
       FIGS. 3B and 3C  illustrate a front view and isometric view of another camera tracking system component  6 ′ which may be used with the surgical system of  FIG. 1  or may be used independent of a surgical robot. For example, the camera tracking system component  6 ′ may be used for providing navigated surgery without use of robotic guidance. One of the differences between the camera tracking system component  6 ′ of  FIGS. 3B and 3C  and the camera tracking system component  6  of  FIG. 3A , is that the camera tracking system component  6 ′ of  FIGS. 3B and 3C  includes a housing that transports the computer platform  910 . The computer platform  910  can be configured to perform camera tracking operations to track DRAs, perform navigated surgery operations that provide surgical navigation information to a display device, e.g., XR headset and/or other display device, and perform other computational operations disclosed herein. The computer platform  910  can therefore include a navigation computer, such as one or more of the navigation computers of  FIG. 14 . 
       FIG. 6  illustrates a block diagram view of the components of the surgical system of  FIG. 5  used for the medical operation. Referring to  FIG. 6 , the navigation cameras  46  on the auxiliary tracking bar has a navigation field-of-view  600  in which the pose (e.g., position and orientation) of the reference array  602  attached to the patient, the reference array  604  attached to the surgical instrument, and the robot arm  20  are tracked. The navigation cameras  46  may be part of the camera tracking system component  6 ′ of  FIGS. 3B and 3C , which includes the computer platform  910  configured to perform the operations described below. The reference arrays enable tracking by reflecting light in known patterns, which are decoded to determine their respective poses by the tracking subsystem of the surgical robot  4 . If the line-of-sight between the patient reference array  602  and the navigation cameras  46  in the auxiliary tracking bar is blocked (for example, by a medical personnel, instrument, etc.), further navigation of the surgical instrument may not be able to be performed and a responsive notification may temporarily halt further movement of the robot arm  20  and surgical robot  4 , display a warning on the display  34 , and/or provide an audible warning to medical personnel. The display  34  is accessible to the surgeon  610  and assistant  612  but viewing requires a head to be turned away from the patient and for eye focus to be changed to a different distance and location. The navigation software may be controlled by a tech personnel  614  based on vocal instructions from the surgeon. 
       FIG. 7  illustrates various display screens that may be displayed on the display  34  of  FIGS. 5 and 6  by the surgical robot  4  when using a navigation function of the surgical system  2 . The display screens can include, without limitation, patient radiographs with overlaid graphical representations of models of instruments that are positioned in the display screens relative to the anatomical structure based on a developed surgical plan and/or based on poses of tracked reference arrays, various user selectable menus for controlling different stages of the surgical procedure and dimension parameters of a virtually projected implant (e.g. length, width, and/or diameter). 
     For navigated surgery, various processing components (e.g., computer platform  910 ) and associated software described below are provided that enable pre-operatively planning of a surgical procedure, e.g., implant placement, and electronic transfer of the plan to computer platform  910  to provide navigation information to one or more users during the planned surgical procedure. 
     For robotic navigation, various processing components (e.g., computer platform  910 ) and associated software described below are provided that enable pre-operatively planning of a surgical procedure, e.g., implant placement, and electronic transfer of the plan to the surgical robot  4 . The surgical robot  4  uses the plan to guide the robot arm  20  and connected end effector  26  to provide a target pose for a surgical tool relative to a patient anatomical structure for a step of the planned surgical procedure. 
     Various embodiments below are directed to using one or more XR headsets that can be worn by the surgeon  610 , the assistant  612 , and/or other medical personnel to provide an improved user interface for receiving information from and/or providing control commands to the surgical robot, the camera tracking system component  6 / 6 ′, and/or other medical equipment in the operating room. 
       FIG. 8  illustrates a block diagram of some electrical components of the surgical robot  4  according to some embodiments of the present disclosure. Referring to  FIG. 8 , a load cell (not shown) may be configured to track force applied to end effector coupler  22 . In some embodiments the load cell may communicate with a plurality of motors  850 ,  851 ,  852 ,  853 , and/or  854 . As load cell senses force, information as to the amount of force applied may be distributed from a switch array and/or a plurality of switch arrays to a controller  846 . Controller  846  may take the force information from load cell and process it with a switch algorithm. The switch algorithm is used by the controller  846  to control a motor driver  842 . The motor driver  842  controls operation of one or more of the motors  850 ,  851 ,  852 ,  853 , and  854 . Motor driver  842  may direct a specific motor to produce, for example, an equal amount of force measured by load cell through the motor. In some embodiments, the force produced may come from a plurality of motors, e.g.,  850 - 854 , as directed by controller  846 . Additionally, motor driver  842  may receive input from controller  846 . Controller  846  may receive information from load cell as to the direction of force sensed by load cell. Controller  846  may process this information using a motion controller algorithm. The algorithm may be used to provide information to specific motor drivers  842 . To replicate the direction of force, controller  846  may activate and/or deactivate certain motor drivers  842 . Controller  846  may control one or more motors, e.g. one or more of  850 - 854 , to induce motion of end effector  26  in the direction of force sensed by load cell. This force-controlled motion may allow an operator to move SCARA  24  and end effector  26  effortlessly and/or with very little resistance. Movement of end effector  26  can be performed to position end effector  26  in any suitable pose (i.e., location and angular orientation relative to defined three-dimensional (3D) orthogonal reference axes) for use by medical personnel. 
     Activation assembly  60 , best illustrated in  FIG. 5 , may form of a bracelet that wraps around end effector coupler  22 . The activation assembly  60  may be located on any part of SCARA  24 , any part of end effector coupler  22 , may be worn by medical personnel (and communicate wirelessly), and/or any combination thereof. Activation assembly  60  may comprise of a primary button and a secondary button. 
     Depressing primary button may allow an operator to move SCARA  24  and end effector coupler  22 . According to one embodiment, once set in place, SCARA  24  and end effector coupler  22  may not move until an operator programs surgical robot  4  to move SCARA  24  and end effector coupler  22 , or is moved using primary button. In some examples, it may require the depression of at least two non-adjacent primary activation switches before SCARA  24  and end effector coupler  22  will respond to operator commands. Depression of at least two primary activation switches may prevent the accidental movement of SCARA  24  and end effector coupler  22  during a medical procedure. 
     Activated by primary button, load cell may measure the force magnitude and/or direction exerted upon end effector coupler  22  by an operator, i.e. medical personnel. This information may be transferred to one or more motors, e.g. one or more of  850 - 854 , within SCARA  24  that may be used to move SCARA  24  and end effector coupler  22 . Information as to the magnitude and direction of force measured by load cell may cause the one or more motors, e.g. one or more of  850 - 854 , to move SCARA  24  and end effector coupler  22  in the same direction as sensed by the load cell. This force-controlled movement may allow the operator to move SCARA  24  and end effector coupler  22  easily and without large amounts of exertion due to the motors moving SCARA  24  and end effector coupler  22  at the same time the operator is moving SCARA  24  and end effector coupler  22 . 
     In some examples, a secondary button may be used by an operator as a “selection” device. During a medical operation, surgical robot  4  may notify medical personnel to certain conditions by the XR headset(s)  920 , display  34  and/or light indicator  28 . The XR headset(s)  920  are each configured to display images on a see-through display screen to form an extended reality image that is overlaid on real-world objects viewable through the see-through display screen. Medical personnel may be prompted by surgical robot  4  to select a function, mode, and/or assess the condition of surgical system  2 . Depressing secondary button a single time may activate certain functions, modes, and/or acknowledge information communicated to medical personnel through the XR headset(s)  920 , display  34  and/or light indicator  28 . Additionally, depressing the secondary button multiple times in rapid succession may activate additional functions, modes, and/or select information communicated to medical personnel through the XR headset(s)  920 , display  34  and/or light indicator  28 . 
     With further reference to  FIG. 8 , electrical components of the surgical robot  4  include platform subsystem  802 , computer subsystem  820 , motion control subsystem  840 , and tracking subsystem  830 . Platform subsystem  802  includes battery  806 , power distribution module  804 , connector panel  808 , and charging station  810 . Computer subsystem  820  includes computer  822 , display  824 , and speaker  826 . Motion control subsystem  840  includes driver circuit  842 , motors  850 ,  851 ,  852 ,  853 ,  854 , stabilizers  855 ,  856 ,  857 ,  858 , end effector connector  844 , and controller  846 . Tracking subsystem  830  includes position sensor  832  and camera converter  834 . Surgical robot  4  may also include a removable foot pedal  880  and removable tablet computer  890 . 
     Input power is supplied to surgical robot  4  via a power source which may be provided to power distribution module  804 . Power distribution module  804  receives input power and is configured to generate different power supply voltages that are provided to other modules, components, and subsystems of surgical robot  4 . Power distribution module  804  may be configured to provide different voltage supplies to connector panel  808 , which may be provided to other components such as computer  822 , display  824 , speaker  826 , driver  842  to, for example, power motors  850 - 854  and end effector coupler  844 , and provided to camera converter  834  and other components for surgical robot  4 . Power distribution module  804  may also be connected to battery  806 , which serves as temporary power source in the event that power distribution module  804  does not receive power from an input power. At other times, power distribution module  804  may serve to charge battery  806 . 
     Connector panel  808  may serve to connect different devices and components to surgical robot  4  and/or associated components and modules. Connector panel  808  may contain one or more ports that receive lines or connections from different components. For example, connector panel  808  may have a ground terminal port that may ground surgical robot  4  to other equipment, a port to connect foot pedal  880 , a port to connect to tracking subsystem  830 , which may include position sensor  832 , camera converter  834 , and DRA tracking cameras  870 . Connector panel  808  may also include other ports to allow USB, Ethernet, HDMI communications to other components, such as computer  822 . In accordance with some embodiments, the connector panel  808  can include a wired and/or wireless interface for operatively connecting one or more XR headsets  920  to the tracking subsystem  830  and/or the computer subsystem  820 . 
     Control panel  816  may provide various buttons or indicators that control operation of surgical robot  4  and/or provide information from surgical robot  4  for observation by an operator. For example, control panel  816  may include buttons to power on or off surgical robot  4 , lift or lower vertical column  16 , and lift or lower stabilizers  855 - 858  that may be designed to engage casters  12  to lock surgical robot  4  from physically moving. Other buttons may stop surgical robot  4  in the event of an emergency, which may remove all motor power and apply mechanical brakes to stop all motion from occurring. Control panel  816  may also have indicators notifying the operator of certain system conditions such as a line power indicator or status of charge for battery  806 . In accordance with some embodiments, one or more XR headsets  920  may communicate, e.g. via the connector panel  808 , to control operation of the surgical robot  4  and/or to received and display information generated by surgical robot  4  for observation by persons wearing the XR headsets  920 . 
     Computer  822  of computer subsystem  820  includes an operating system and software to operate assigned functions of surgical robot  4 . Computer  822  may receive and process information from other components (for example, tracking subsystem  830 , platform subsystem  802 , and/or motion control subsystem  840 ) in order to display information to the operator. Further, computer subsystem  820  may provide output through the speaker  826  for the operator. The speaker may be part of the surgical robot, part of an XR headset  920 , or within another component of the surgical system  2 . The display  824  may correspond to the display  34  shown in  FIGS. 1 and 2 . 
     Tracking subsystem  830  may include position sensor  832  and camera converter  834 . Tracking subsystem  830  may correspond to the camera tracking system component  6  of  FIG. 3 . The DRA tracking cameras  870  operate with the position sensor  832  to determine the pose of DRAs  52 . This tracking may be conducted in a manner consistent with the present disclosure including the use of infrared or visible light technology that tracks the location of active or passive elements of DRAs  52 , such as LEDs or reflective markers, respectively. 
     Functional operations of the tracking subsystem  830  and the computer subsystem  820  can be included in the computer platform  910 , which can be transported by the camera tracking system component  6 ′ of  FIGS. 3A and 3B . The tracking subsystem  830  can be configured to determine the poses, e.g., location and angular orientation of the tracked DRAs. The computer platform  910  can also include a navigation controller that is configured to use the determined poses to provide navigation information to users that guides their movement of tracked tools relative to position-registered patient images and/or tracked anatomical structures during a planned surgical procedure. The computer platform  910  can display information on the display of  FIGS. 3B and 3C  and/or to one or more XR headsets  920 . The computer platform  910 , when used with a surgical robot, can be configured to communicate with the computer subsystem  820  and other subsystems of  FIG. 8  to control movement of the end effector  26 . For example, as will be explained below the computer platform  910  can generate a graphical representation of a patient&#39;s anatomical structure, surgical tool, user&#39;s hand, etc. with a displayed size, shape, color, and/or pose that is controlled based on the determined pose(s) of one or more the tracked DRAs, and which the graphical representation that is displayed can be dynamically modified to track changes in the determined poses over time. 
     Motion control subsystem  840  may be configured to physically move vertical column  16 , upper arm  18 , lower arm  20 , or rotate end effector coupler  22 . The physical movement may be conducted through the use of one or more motors  850 - 854 . For example, motor  850  may be configured to vertically lift or lower vertical column  16 . Motor  851  may be configured to laterally move upper arm  18  around a point of engagement with vertical column  16  as shown in  FIG. 2 . Motor  852  may be configured to laterally move lower arm  20  around a point of engagement with upper arm  18  as shown in  FIG. 2 . Motors  853  and  854  may be configured to move end effector coupler  22  to provide translational movement and rotation along in about three-dimensional axes. The computer platform  910  shown in  FIG. 9  can provide control input to the controller  846  that guides movement of the end effector coupler  22  to position a passive end effector, which is connected thereto, with a planned pose (i.e., location and angular orientation relative to defined 3D orthogonal reference axes) relative to an anatomical structure that is to be operated on during a planned surgical procedure. Motion control subsystem  840  may be configured to measure position of the end effector coupler  22  and/or the end effector  26  using integrated position sensors (e.g. encoders). 
       FIG. 9  illustrates a block diagram of components of a surgical system that includes imaging devices (e.g., C-Arm  104 , O-Arm  106 , etc.) connected to a computer platform  910  which can be operationally connected to a camera tracking system component  6  ( FIG. 3A ) or  6 ′ ( FIGS. 3B,3C ) and/or to surgical robot  4  according to some embodiments of the present disclosure. Alternatively, at least some operations disclosed herein as being performed by the computer platform  910  may additionally or alternatively be performed by components of a surgical system. 
     Referring to  FIG. 9 , the computer platform  910  includes a display  912 , at least one processor circuit  914  (also referred to as a processor for brevity), at least one memory circuit  916  (also referred to as a memory for brevity) containing computer readable program code  918 , and at least one network interface  902  (also referred to as a network interface for brevity). The display  912  may be part of an XR headset  920  in accordance with some embodiments of the present disclosure. The network interface  902  can be configured to connect to a C-Arm imaging device  104  in  FIG. 10 , an O-Arm imaging device  106  in  FIG. 11 , another medical imaging device, an image database  950  containing patient medical images, components of the surgical robot  4 , and/or other electronic equipment. 
     When used with a surgical robot  4 , the display  912  may correspond to the display  34  of  FIG. 2  and/or the tablet  890  of  FIG. 8  and/or the XR headset  920  that is operatively connected to the surgical robot  4 , the network interface  902  may correspond to the platform network interface  812  of  FIG. 8 , and the processor  914  may correspond to the computer  822  of  FIG. 8 . The network interface  902  of the XR headset  920  may be configured to communicate through a wired network, e.g., thin wire ethernet, and/or through wireless RF transceiver link according to one or more wireless communication protocols, e.g., WLAN, 3GPP 4G and/or  5 G (New Radio) cellular communication standards, etc. 
     The processor  914  may include one or more data processing circuits, such as a general purpose and/or special purpose processor, e.g., microprocessor and/or digital signal processor. The processor  914  is configured to execute the computer readable program code  918  in the memory  916  to perform operations, which may include some or all of the operations described herein as being performed for surgery planning, navigated surgery, and/or robotic surgery. 
     The computer platform  910  can be configured to provide surgery planning functionality. The processor  914  can operate to display on the display device  912  and/or on the XR headset  920  an image of an anatomical structure, e.g., vertebra, that is received from one of the imaging devices  104  and  106  and/or from the image database  950  through the network interface  920 . The processor  914  receives an operator&#39;s definition of where the anatomical structure shown in one or more images is to have a surgical procedure, e.g., screw placement, such as by the operator touch selecting locations on the display  912  for planned procedures or using a mouse-based cursor to define locations for planned procedures. When the image is displayed in the XR headset  920 , the XR headset can be configured to sense in gesture-based commands formed by the wearer and/or sense voice based commands spoken by the wearer, which can be used to control selection among menu items and/or control how objects are displayed on the XR headset  920  as will be explained in further detail below. 
     The computer platform  910  can be configured to enable anatomy measurement, which can be particularly useful for knee surgery, like measurement of various angles determining center of hip, center of angles, natural landmarks (e.g. transepicondylar line, Whitesides line, posterior condylar line), etc. Some measurements can be automatic while some others can involve human input or assistance. The computer platform  910  may be configured to allow an operator to input a choice of the correct implant for a patient, including choice of size and alignment. The computer platform  910  may be configured to perform automatic or semi-automatic (involving human input) segmentation (image processing) for CT images or other medical images. The surgical plan for a patient may be stored in a cloud-based server, which may correspond to database  950 , for retrieval by the surgical robot  4 . 
     During orthopedic surgery, for example, a surgeon may choose which cut to make (e.g. posterior femur, proximal tibia etc.) using a computer screen (e.g. touchscreen) or extended reality (XR) interaction (e.g., hand gesture based commands and/or voice based commands) via, e.g., the XR headset  920 . The computer platform  910  can generate navigation information which provides visual guidance to the surgeon for performing the surgical procedure. When used with the surgical robot  4 , the computer platform  910  can provide guidance that allows the surgical robot  4  to automatically move the end effector  26  to a target pose so that the surgical tool is aligned with a target location to perform the surgical procedure on an anatomical structure. 
     In some embodiments, the surgical system  900  can use two DRAs to track patient anatomy position, such as one connected to patient tibia and one connected to patient femur. The system  900  may use standard navigated instruments for the registration and checks (e.g. a pointer similar to the one used in Globus ExcelsiusGPS system for spine surgery). 
     A particularly challenging task in navigated surgery is how to plan the position of an implant in spine, knee, and other anatomical structures where surgeons struggle to perform the task on a computer screen which is a 2D representation of the 3D anatomical structure. The system  900  could address this problem by using the XR headset  920  to display a three-dimensional (3D) computer generated representations of the anatomical structure and a candidate implant device. The computer generated representations are scaled and posed relative to each other on the display screen under guidance of the computer platform  910  and which can be manipulated by a surgeon while viewed through the XR headset  920 . A surgeon may, for example, manipulate the displayed computer-generated representations of the anatomical structure, the implant, a surgical tool, etc., using hand gesture based commands and/or voice based commands that are sensed by the XR headset  920 . 
     For example, a surgeon can view a displayed virtual handle on a virtual implant, and can manipulate (e.g., grab and move) the virtual handle to move the virtual implant to a desired pose and adjust a planned implant placement relative to a graphical representation of an anatomical structure. Afterward, during surgery, the computer platform  910  could display navigation information through the XR headset  920  that facilitates the surgeon&#39;s ability to more accurately follow the surgical plan to insert the implant and/or to perform another surgical procedure on the anatomical structure. When the surgical procedure involves bone removal, the progress of bone removal, e.g., depth of cut, can be displayed in real-time through the XR headset  920 . Other features that may be displayed through the XR headset  920  can include, without limitation, gap or ligament balance along a range of joint motion, contact line on the implant along the range of joint motion, ligament tension and/or laxity through color or other graphical renderings, etc. 
     The computer platform  910 , in some embodiments, can allow planning for use of standard surgical tools and/or implants, e.g., posterior stabilized implants and cruciate retaining implants, cemented and cementless implants, revision systems for surgeries related to, for example, total or partial knee and/or hip replacement and/or trauma. 
     An automated imaging system can be used in conjunction with the computer platform  910  to acquire pre-operative, intra-operative, post-operative, and/or real-time image data of an anatomical structure. Example automated imaging systems are illustrated in  FIGS. 10 and 11 . In some embodiments, the automated imaging system is a C-arm  104  ( FIG. 10 ) imaging device or an O-arm®  106  ( FIG. 11 ). (O-arm® is copyrighted by Medtronic Navigation, Inc. having a place of business in Louisville, Colo., USA). It may be desirable to take x-rays of a patient from a number of different positions, without the need for frequent manual repositioning of the patient which may be required in an x-ray system. C-arm  104  x-ray diagnostic equipment may solve the problems of frequent manual repositioning and may be well known in the medical art of surgical and other interventional procedures. As illustrated in  FIG. 10 , a C-arm includes an elongated C-shaped member terminating in opposing distal ends  112  of the “C” shape. C-shaped member is attached to an x-ray source  114  and an image receptor  116 . The space within C-arm  104  of the arm provides room for the physician to attend to the patient substantially free of interference from the x-ray support structure. 
     The C-arm is mounted to enable rotational movement of the arm in two degrees of freedom, (i.e. about two perpendicular axes in a spherical motion). C-arm is slidably mounted to an x-ray support structure, which allows orbiting rotational movement of the C-arm about its center of curvature, which may permit selective orientation of x-ray source  114  and image receptor  116  vertically and/or horizontally. The C-arm may also be laterally rotatable, (i.e. in a perpendicular direction relative to the orbiting direction to enable selectively adjustable positioning of x-ray source  114  and image receptor  116  relative to both the width and length of the patient). Spherically rotational aspects of the C-arm apparatus allow physicians to take x-rays of the patient at an optimal angle as determined with respect to the particular anatomical condition being imaged. 
     The O-arm®  106  illustrated in  FIG. 11  includes a gantry housing  124  which may enclose an image capturing portion, not illustrated. The image capturing portion includes an x-ray source and/or emission portion and an x-ray receiving and/or image receiving portion, which may be disposed about one hundred and eighty degrees from each other and mounted on a rotor (not illustrated) relative to a track of the image capturing portion. The image capturing portion may be operable to rotate three hundred and sixty degrees during image acquisition. The image capturing portion may rotate around a central point and/or axis, allowing image data of the patient to be acquired from multiple directions or in multiple planes. 
     The O-arm®  106  with the gantry housing  124  has a central opening for positioning around an object to be imaged, a source of radiation that is rotatable around the interior of gantry housing  124 , which may be adapted to project radiation from a plurality of different projection angles. A detector system is adapted to detect the radiation at each projection angle to acquire object images from multiple projection planes in a quasi-simultaneous manner. The gantry may be attached to a support structure O-arm® support structure, such as a wheeled mobile cart with wheels, in a cantilevered fashion. A positioning unit translates and/or tilts the gantry to a planned position and orientation, preferably under control of a computerized motion control system. The gantry may include a source and detector disposed opposite one another on the gantry. The source and detector may be secured to a motorized rotor, which may rotate the source and detector around the interior of the gantry in coordination with one another. The source may be pulsed at multiple positions and orientations over a partial and/or full three hundred and sixty degree rotation for multi-planar imaging of a targeted object located inside the gantry. The gantry may further comprise a rail and bearing system for guiding the rotor as it rotates, which may carry the source and detector. Both and/or either O-arm®  106  and C-arm  104  may be used as automated imaging system to scan a patient and send information to the surgical system  2 . 
     Images captured by an imaging system can be displayed on the XR headset  920  and/or another display device of the computer platform  910 , the surgical robot  4 , and/or another component of the surgical system  900 . The XR headset  920  may be connected to one or more of the imaging devices  104  and/or  106  and/or to the image database  950 , e.g., via the computer platform  910 , to display images therefrom. A user may provide control inputs through the XR headset  920 , e.g., gesture and/or voice based commands, to control operation of one or more of the imaging devices  104  and/or  106  and/or the image database  950 . 
       FIG. 12  illustrates a block diagram view of the components of a surgical system that include a pair of XR headsets  1200  and  1210  (head-mounted displays HMD1 and HMD2), which may correspond to the XR headset  920  shown in  FIG. 13  and operate in accordance with some embodiments of the present disclosure. 
     Referring to the example scenario of  FIG. 12 , the assistant  612  and surgeon  610  are both wearing the XR headsets  1210  and  1210 , respectively. It is optional for the assistant  612  to wear the XR headset  1210 . The XR headsets  1200  and  1210  are configured to provide an interactive environment through which the wearers can view and interact with information related to a surgical procedure as will be described further below. This interactive XR based environment may eliminate a need for the tech personnel  614  to be present in the operating room and may eliminate a need for use of the display  34  shown in  FIG. 6 . Each XR headset  1200  and  1210  can include one or more cameras that are be configured to provide an additional source of tracking of DRAs or other reference arrays attached to instruments, an anatomical structure, the end effector  26 , and/or other equipment. In the example of  FIG. 12 , XR headset  1200  has a field-of-view (FOV)  1202  for tracking DRAs and other objects, XR headset  1210  has a FOV  1212  partially overlapping FOV  1202  for tracking DRAs and other objects, and the navigation cameras  46  has another FOV  600  partially overlapping FOVs  1202  and  1212  for tracking DRAs and other objects. 
     If one or more cameras is obstructed from viewing a DRA attached to a tracked object, e.g., a surgical instrument, but the DRA is in view of one or more other cameras the tracking subsystem  830  and/or navigation controller  828  can continue to track the object seamlessly without loss of navigation. Additionally, if there is partial occlusion of the DRA from the perspective of one camera, but the entire DRA is visible via multiple camera sources, the tracking inputs of the cameras can be merged to continue navigation of the DRA. One of the XR headsets and/or the navigation cameras  46  may view and track the DRA on another one of the XR headsets to enable the computer platform  910  ( FIGS. 9 and 14 ), the tracking subsystem  830 , and/or another computing component to determine the pose of the DRA relative to one or more defined coordinate systems, e.g., of the XR headsets  1200 / 1210 , the navigation cameras  46 , and/or another coordinate system defined for the patient, table, and/or room. 
     The XR headsets  1200  and  1210  can be operatively connected to view video, pictures, and/or other information received from and/or to provide commands that control various equipment in the surgical room, including but not limited to neuromonitoring, microscopes, video cameras, and anesthesia systems. Data from the various equipment may be processed and displayed within the headset, for example the display of patient vitals or the microscope feed. 
     Example XR Headset Components and Integration to Navigated Surgery, Surgical Robots, and Other Equipment 
       FIG. 13  illustrates an XR headset  920  which is configured in accordance with some embodiments of the present disclosure. The XR headset includes a headband  1306  configured to secure the XR headset to a wearer&#39;s head, an electronic component enclosure  1304  supported by the headband  1306 , and a display screen  1302  that extends laterally across and downward from the electronic component enclosure  1304 . The display screen  1302  may be a see-through LCD display device or a semi-reflective lens that reflects images projected by a display device toward the wearer&#39;s eyes. A set of DRA fiducials, e.g., dots are painted or attached in a spaced apart known arranged on one or both sides of the headset. The DRA on the headset enables the navigation cameras on the auxiliary tracking bar to track pose of the headset  920  and/or enables another XR headset to track pose of the headset  920 . 
     The display screen  1302  operates as a see-through display screen, also referred to as a combiner, that reflects light from display panels of a display device toward the user&#39;s eyes. The display panels can be located between the electronic component enclosure and the user&#39;s head, and angled to project virtual content toward the display screen  1302  for reflection toward the user&#39;s eyes. The display screen  1302  is semi-transparent and semi-reflective allowing the user to see reflected virtual content superimposed on the user&#39;s view of a real-world scene. The display screen  1302  may have different opacity regions, such as the illustrated upper laterally band which has a higher opacity than the lower laterally band. Opacity of the display screen  1302  may be electronically controlled to regulate how much light from the real-world scene passes through to the user&#39;s eyes. A high opacity configuration of the display screen  1302  results in high-contrast virtual images overlaid on a dim view of the real-world scene. A low opacity configuration of the display screen  1302  can result in more faint virtual images overlaid on a clearer view of the real-world scene. The opacity may be controlled by applying an opaque material on a surface of the display screen  1302 . 
     According to some embodiments the surgical system includes an XR headset  920  and an XR headset controller, e.g., controller  1430  in  FIG. 14  or controller  3410  in  FIG. 34 . The XR headset  920  is configured to be worn by a user during a surgical procedure and has a see-through display screen  1302  that is configured to display an XR image and to allow at least a portion of a real-world scene to pass therethrough for viewing by the user. The XR headset  920  also includes an opacity filter positioned between at least one of the user&#39;s eyes and the real-world scene when the see-through display screen  1302  is viewed by the user. The opacity filter is configured to provide opaqueness to light from the real-world scene. The XR headset controller is configured to communicate with a navigation controller, e.g., controller(s)  828 A,  828 B, and/or  828 C in  FIG. 14 , to receive navigation information from the navigation controller which provides guidance to the user during the surgical procedure on an anatomical structure, and is further configured to generate the XR image based on the navigation information for display on the see-through display screen  1302 . 
     Opacity of the display screen  1302  may be configured as a gradient having a more continuously changing opacity with distance downward from a top portion of the display screen  1302 . The gradient&#39;s darkest point can be located at the top portion of the display screen  1302 , and gradually becoming less opaque further down on the display screen  1302  until the opacity is transparent or not present. In an example further embodiment, the gradient can change from about 90% opacity to entirely transparent approximately at the mid-eye level of the display screen  1302 . With the headset properly calibrated and positioned, the mid-eye level can correspond to the point where the user would look straight out, and the end of the gradient would be located at the “horizon” line of the eye. The darker portion of the gradient will allow crisp, clear visuals of the virtual content and help to block the intrusive brightness of the overhead operating room lights. 
     Using an opacity filter in this manner enables the XR headset  920  to provide virtual reality (VR) capabilities, by substantially or entirely blocking light from the real-world scene, along an upper portion of the display screen  1302  and to provide AR capabilities along a middle or lower portion of the display screen  1302 . This allows the user to have the semi-translucence of AR where needed and allowing clear optics of the patient anatomy during procedures. Configuring the display screen  1302  as a gradient instead of as a more constant opacity band can enable the wearer to experience a more natural transition between a more VR type view to a more AR type view without experiencing abrupt changes in brightness of the real-world scene and depth of view that may otherwise strain the eyes such as during more rapid shifting between upward and downward views. 
     The display panels and display screen  1302  can be configured to provide a wide field of view see-through XR display system. In one example configuration they provide an 80° diagonal field-of-view (FOV) with 55° of vertical coverage for a user to view virtual content. Other diagonal FOV angles and vertical coverage angles can be provided through different size display panels, different curvature lens, and/or different distances and angular orientations between the display panels and curved display screen  1302 . In some embodiments, having an XR headset with a wide field of view allows the XR headset to display a real-world registered XR images to a user while the user&#39;s field of vision is not centered on the real-world coordinates associated with the real-world registered XR image. 
       FIG. 14  illustrates electrical components of the XR headset  920  that can be operatively connected to the computer platform  910 , to one or more of the imaging devices, such as the C-arm imaging device  104 , the O-arm imaging device  106 , and/or the image database  950 , and/or to the surgical robot  800  in accordance with various embodiments of the present disclosure. 
     The XR headset  920  provides an improved human interface for performing navigated surgical procedures. The XR headset  920  can be configured to provide functionalities, e.g., via the computer platform  910 , that include without limitation any one or more of: identification of hand gesture based commands and/or voice based commands, display XR graphical objects on a display device  1450 . The display device  1450  may a video projector, flat panel display, etc., which projects the displayed XR graphical objects on the display screen  1302 . The user can view the XR graphical objects as an overlay anchored to particular real-world objects viewed through the display screen  1302  ( FIG. 13 ). The XR headset  920  may additionally or alternatively be configured to display on the display screen  1450  video feeds from cameras mounted to one or more XR headsets  920  and other cameras. 
     Electrical components of the XR headset  920  can include a plurality of cameras  1440 , a microphone  1442 , a gesture sensor  1444 , a pose sensor (e.g., inertial measurement unit (IMU))  1446 , a display module  1448  containing the display device  1450 , and a wireless/wired communication interface  1452 . As will be explained below, the cameras  1440  of the XR headset may be visible light capturing cameras, near infrared capturing cameras, or a combination of both. 
     The cameras  1440  may be configured operate as the gesture sensor  1444  by capturing for identification user hand gestures performed within the field of view of the camera(s)  1440 . Alternatively the gesture sensor  1444  may be a proximity sensor and/or a touch sensor that senses hand gestures performed proximately to the gesture sensor  1444  and/or senses physical contact, e.g. tapping on the sensor or the enclosure  1304 . The pose sensor  1446 , e.g., IMU, may include a multi-axis accelerometer, a tilt sensor, and/or another sensor that can sense rotation and/or acceleration of the XR headset  920  along one or more defined coordinate axes. Some or all of these electrical components may be contained in the component enclosure  1304  or may be contained in another enclosure configured to be worn elsewhere, such as on the hip or shoulder. 
     As explained above, the surgical system  2  includes a camera tracking system component  6 / 6 ′ and a tracking subsystem  830  which may be part of the computer platform  910 . The surgical system may include imaging devices (e.g., C-arm  104 , O-arm  106 , and/or image database  950 ) and/or a surgical robot  4 . The tracking subsystem  830  is configured to determine a pose of DRAs attached to an anatomical structure, an end effector, a surgical tool, etc. A navigation controller  828  is configured to determine a target pose for the surgical tool relative to an anatomical structure based on a surgical plan, e.g., from a surgical planning function performed by the computer platform  910  of  FIG. 9 , defining where a surgical procedure is to be performed using the surgical tool on the anatomical structure and based on a pose of the anatomical structure determined by the tracking subsystem  830 . The navigation controller  828  may be further configured to generate steering information based on the target pose for the surgical tool, the pose of the anatomical structure, and the pose of the surgical tool and/or the end effector, where the steering information indicates where the surgical tool and/or the end effector of a surgical robot should be moved to perform the surgical plan. 
     The electrical components of the XR headset  920  can be operatively connected to the electrical components of the computer platform  910  through a wired/wireless interface  1452 . The electrical components of the XR headset  920  may be operatively connected, e.g., through the computer platform  910  or directly connected, to various imaging devices, e.g., the C-arm imaging device  104 , the I/O-arm imaging device  106 , the image database  950 , and/or to other medical equipment through the wired/wireless interface  1452 . 
     The surgical system  2  further includes at least one XR headset controller  1430  (also referred to as “XR headset controller” for brevity) that may reside in the XR headset  920 , the computer platform  910 , and/or in another system component connected via wired cables and/or wireless communication links. Various functionality is provided by software executed by the XR headset controller  1430 . The XR headset controller  1430  is configured to receive navigation information from the navigation controller  828  which provides guidance to the user during the surgical procedure on an anatomical structure, and is configured to generate an XR image based on the navigation information for display on the display device  1450  for projection on the see-through display screen  1302 . 
     The configuration of the display device  1450  relative to the display screen (also referred to as “see-through display screen”)  1302  is configured to display XR images in a manner such that when the user wearing the XR headset  920  looks through the display screen  1302  the XR images appear to be in the real world. The display screen  1302  can be positioned by the headband  1306  in front of the user&#39;s eyes. 
     The XR headset controller  1430  can be within a housing that is configured to be worn on a user&#39;s head or elsewhere on the user&#39;s body while viewing the display screen  1302  or may be remotely located from the user viewing the display screen  1302  while being communicatively connected to the display screen  1302 . The XR headset controller  1430  can be configured to operationally process signaling from the cameras  1440 , the microphone  142 , and/or the pose sensor  1446 , and is connected to display XR images on the display device  1450  for user viewing on the display screen  1302 . Thus, the XR headset controller  1430  illustrated as a circuit block within the XR headset  920  is to be understood as being operationally connected to other illustrated components of the XR headset  920  but not necessarily residing within a common housing (e.g., the electronic component enclosure  1304  of  FIG. 13 ) or being otherwise transportable by the user. For example, the XR headset controller  1430  may reside within the computer platform  910  which, in turn, may reside within a housing of the computer tracking system component  6 ′ shown in  FIGS. 3B and 3C . 
     Example User Views Through the XR Headset 
     The XR headset operations can display both 2D images and 3D models on the display screen  1302 . The 2D images may preferably be displayed in a more opaque band of the display screen  1302  (upper band) and the 3D model may be more preferably displayed in the more transparent band of the display screen  1302 , otherwise known as the environmental region (bottom band). Below the lower band where the display screen  1302  ends the wearer has an unobstructed view of the surgical room. It is noted that where XR content is display on the display screen  1302  may be fluidic. It is possible that where the 3D content is displayed moves to the opaque band depending on the position of the headset relative to the content, and where 2D content is displayed can be placed in the transparent band and stabilized to the real world. Additionally, the entire display screen  1302  may be darkened under electronic control to convert the headset into virtual reality for surgical planning or completely transparent during the medical procedure. As explained above, the XR headset  920  and associated operations not only support navigated procedures, but also can be performed in conjunction with robotically assisted procedures. 
       FIG. 16  illustrates an example view through the display screen  1302  of the XR headset  920  for providing navigation assistance to a user who is manipulating a surgical tool  1602  during a medical procedure in accordance with some embodiments of the present disclosure. Referring to  FIG. 16 , when the surgical tool  1602  is brought in vicinity of a tracked anatomical structure so that dynamic reference arrays  1630  and  1632 , connected to the surgical tool  1602 , become within the field of view of the cameras  1440  ( FIG. 15 ) and/or  46  ( FIG. 6 ), a graphical representation  1600  of the tool can be displayed in 2D and/or 3D images in relation to a graphical representation  1610  of the anatomical structure. The user can use the viewed graphical representations to adjust a trajectory  1620  of the surgical tool  1602 , which can be illustrated as extending from the graphical representation  2000  of the tool through the graphical representation  1610  of the anatomical structure. The XR headset  920  may also display textual information and other objects  1640 . The dashed line  1650  extending across the viewed display screen represents an example division between different opacity level upper and lower bands. 
     Other types of XR images (virtual content) that can be displayed on the display screen  1302  can include, but are not limited to any one or more of:
         I) 2D Axial, Sagittal and/or Coronal views of patient anatomy;   2) overlay of planned vs currently tracked tool and surgical implant locations;   3) gallery of preoperative images;   4) video feeds from microscopes and other similar systems or remote video conferencing;   5) options and configuration settings and buttons;   6) floating 3D models of patient anatomy with surgical planning information;   7) real-time tracking of surgical instruments relative to floating patient anatomy;   8) augmented overlay of patient anatomy with instructions and guidance; and   9) augmented overlay of surgical equipment.       

     Example Configuration of Cameras for Tracking System Component 
       FIG. 17  illustrates example configuration of an auxiliary tracking bar  46  having two pairs of stereo navigation cameras configured in accordance with some embodiments of the present disclosure. The auxiliary tracking bar  46  is part of the camera tracking system component of  FIGS. 3A, 3B, and 3C . The stereo navigation cameras include a stereo pair of spaced apart visible light capturing cameras and another stereo pair of spaced apart near infrared capturing cameras, in accordance with one embodiment. Alternatively, only one stereo pair of visible light capturing cameras or only one stereo pair of near infrared capture cameras can used in the auxiliary tracking bar  46 . Any plural number of near infrared and/or visible light cameras can be used. 
     Pose Measurement Chaining 
     As explained above, navigated surgery can include computer vision tracking and determination of pose (e.g., position and orientation in a six degree-of-freedom coordinate system) of surgical instruments, such as by determining pose of attached DRAs that include spaced apart fiducials, e.g., disks or spheres, arranged in a known manner. The computer vision uses spaced apart navigation cameras, e.g., stereo cameras, that are configured to capture near infrared and/or visible light. In this scenario, there are three parameters jointly competing for optimization: (1) accuracy, (2) robustness, and (3) user ergonomics during a surgical procedure. 
     Some further aspects of the present disclosure are directed to computer operations that combine (chain) measured poses in ways that can improve optimization of one or more of the above three parameters by incorporating additional navigation cameras mounted to one or more XR headsets. As shown in  FIG. 17 , a stereo pair of visible light tracking cameras and another stereo pair of near infrared tracking navigation cameras can be attached to the auxiliary tracking bar of the camera tracking system component in accordance with some embodiments of the present disclosure. Operational algorithms are disclosed that analyze the pose of DRAs that are fully observed or partially observed (e.g., when less than all of the fiducials of a DRA are viewed by a pair of stereo cameras), and combine the observed poses or partial poses in ways that can improve accuracy, robustness, and/or ergonomics during navigated surgery. 
     As explained above, the XR headset may be configured to augment a real-world scene with computer generated XR images. The XR headset may be configured to provide an XR viewing environment by displaying the computer generated XR images on a see-through display screen that allows light from the real-world scene to pass therethrough for combined viewing by the user. Alternatively, the XR headset may be configured to provide a VR viewing environment by preventing or substantially preventing light from the real-world scene from being directly viewed by the user along the viewing path of the displayed XR images. An XR headset can be configured to provide both AR and VR viewing environments. In one embodiment, both AR and VR viewing environments are provided by lateral bands of substantially differing opacity arranged between the see-through display screen and the real-world scene, so that a VR viewing environment is provided for XR images aligned with a high opacity band and an AR viewing environment is provided for XR images aligned with the low opacity band. In another embodiment, both AR and VR viewing environments are provided by computer adjustable control of an opacity filter that variably constrains how much light from the real-world scene passes through a see-through display screen for combining with the XR images viewed by the user. Thus, the XR headset can also be referred to as an AR headset or a VR headset. 
     As was also explained above, the XR headset can include near infrared tracking cameras and/or visible light tracking cameras that are configured to track fiducials of DRAs connected to surgical instruments, patient anatomy, other XR headset(s), and/or a robotic end effector. Using near infrared tracking and/or visible light tracking on the XR headset provides additional tracking volume coverage beyond what cameras on a single auxiliary tracking bar can provide. Adding near infrared tracking cameras to the existing auxiliary tracking bar allows for the headset location to be tracked more robustly but less accurately than in visible light. Mechanically calibrating the visible and near infrared tracking coordinate systems enables the coordinate systems to be aligned sufficiently to perform 3D DRA fiducials triangulation operations using stereo matching to jointly identify pose of the DRA fiducials between the visible and near infrared tracking coordinate systems. Using both visible and near infrared tracking coordinate systems can enable any one or more of: (a) identifying tools that would not be identified using a single coordinate system; (b) increased pose tracking accuracy; (c) enabling a wider range of motion without losing tracking of surgical instruments, patient anatomy, and/or a robotic end effector; and (d) naturally track an XR headset in the same coordinate system as the navigated surgical instruments. 
     Generate XR Image Based on Pose of XR Headset in a Real-World Coordinate System 
     Various operations that can be performed by the surgical system  2  to provide navigation assistance through a XR headset for a surgical tool during a medical procedure are now described with reference to the example embodiments of  FIGS. 18-26 . 
     For navigated surgeries, some surgeons employ techniques that involve taking multiple scans of a patient&#39;s anatomy and using images represented on a 2D screen to navigate their tools to the correct position and orientation. Surgical tools can be tracked and displayed as an overlay onto the scanned images, allowing the surgeon to see the position and orientation (also referred to as pose) of the tool relative to the anatomy with as much accuracy as the tool tracking system allows, without needing to physically expose the patient&#39;s anatomy (i.e. through minimally invasive surgery (“MIS”)). This process can allow for minimally invasive surgeries, however, these techniques can present additional difficulties. 
     In some examples, free-hand and robotically-navigated surgery can require interaction with a 2D display (such as a computer monitor). The display can be used to view scanned patient images, plan implant placement, and, in the case of robot-navigated surgery, control the robot. Sterile drapes may be placed over the touch screen monitor or computer mouse interface preventing accurate and smooth physical controls. Furthermore, if the monitor is outside the surgeon&#39;s field of view when looking at the patient, the surgeon may be forced to look away from the surgical site repeatedly in order to view imagery. 
     In additional or alternative examples, navigated tools can be displayed using 2D splice images from the scans, such as the axial and sagittal views. However, navigating several 2D images simultaneously can be unintuitive and difficult for new surgeons to learn. Although processes can use the CT and X-Ray scans to create reconstructions of the scanned anatomy and generate computerized 3D models, navigating, viewing, and manipulating a 3D model can be impractical with a 2D display. 
     Using an XR display in a surgical setting can allow for the display of patient information over the real world in 3D. However, displaying XR content in the context of surgical navigation presents additional challenges. For example, motion sickness is a common problem when using large field-of-view XR displays, but can be minimized with careful planning of user interfaces. Large fields of head-registered content are known to be a common cause of motion sickness and can be averted by using world-registered or object-registered content as described in various embodiments herein. 
     Furthermore, as shown in  FIGS. 18-22 , using patient-registered alternate reality (AR) content through XR headsets can, by its nature, be prone to pose error. In addition to error accrued from tool tracking (one of the most significant sources of error with current surgical displays), error can be introduced from tracking the XR headset, the calibration of the headset optics, and pose of the headset relative to the surgeon&#39;s line of sight. Without tracking visual occlusions, the imagery may not properly occlude objects behind the display and could interfere with the surgeon&#39;s vision of the surgical site. Moreover, error in the imagery may not be immediately obvious if the patient anatomy is not exposed or is occluded by the XR content, which may cause the surgeon to overly rely on incorrect information. 
       FIG. 18  illustrates an example of a 2D screen that can be referenced by a surgeon to aid in positioning a tool and/or implant during a surgical procedure.  FIG. 19  illustrates an example of the actual surgical procedure associated with  FIG. 18 . The location of a surgeon&#39;s tool can be displayed relative to scanned imagery by tracking the physical tool&#39;s location relative to the patient. The display may show a displayed location of the tool  1810  and an ideal location for an implant at location  1820 . However, the tracking may not be perfect and the error introduced by this imperfection can cause the displayed location of a tool to be displaced. In the example of  FIGS. 18-19 , the tool may actually be at location  1850  relative to the anatomical structure and the resulting implant may be at location  1860  relative to the anatomical structure. If the pose given by the tool tracking is incorrect by an error offset  1890 , the tool in the display  1810  will be offset by the error offset  1890  relative to the actual tool location  1850 . Because the surgeon uses the offset display to guide their instruments to the implant location, the implant will be slightly misplaced by an error offset  1890  from where it should have ideally gone in the surgeon&#39;s plan. 
       FIGS. 20-22  illustrate an example of an XR image that can be used during the same surgical procedure of  FIGS. 18-19  and another view of the corresponding surgical procedure. Using an XR display to navigate surgery still requires tool tracking, which creates the error offset  1890 . However, other sources of error, such as tracking the XR headset and errors in the calibration of the XR display, cumulatively generate another considerable offset, represented by XR display offset error  2092 . When viewing patient-registered or anatomy-registered XR content, the XR display offset error  2092  causes the XR content  2070  to be visually displaced from an actual location  2030  of the anatomical structure. The XR content obstructs the surgeon&#39;s view of the patient, so they place their instrument at a real location  2110  relative to the XR content. Additionally, guidance is provided based on the tracked tool position, so the total difference between the ideal implant location from the actual resulting implant location can be as much as the sum of the error offset  1890  and the XR display offset error  2092   
     If world-registered XR content is used, as disclosed here, the XR display offset error  2092  still exists. However, because the XR content is decoupled from the patient and does not obstruct the surgeon&#39;s view, the XR display offset error  2092  does not affect the surgeon&#39;s tool placement or the display of guidance relative to the scanned anatomy. Instead, the difference between the ideal implant location  1820  and the resulting implant location  1860  is limited to error offset  1890 , the same as current surgical navigation display methods. 
     Various embodiments described herein use a 3D reconstructed anatomical model view for XR displays as illustrated in  FIG. 23 . Rather than providing navigation and interaction from a head-registered or patient-registered manner, information is shown relative to a world-registered 3D model of the patient&#39;s anatomy  2320  “floating” above the patient. Combining the XR display  2310  with the ability to track hand movements adds another level of interactivity. In addition to displaying a virtual tool  2333  and virtual implant position relative to the virtual patient anatomy  2320 , the XR 3D Anatomy View can be interactive and used to control a surgical robot. 
     In  FIG. 23 , the surgeon  22390  uses the 3D Anatomical View for navigation during spinal surgery, illustrated from the point-of-view of another person using an XR headset across the surgical table. The patient  2380  has been scanned and the images have been used to construct a 3D model of the spine  2320 , shown in the XR region  2310 . The surgical plan dictates the ideal tool location, which is displayed in the floating model. A 3D model representation of the surgeon&#39;s tool  2335  is also shown as a virtual tool  2333  relative to the spine model  2320  based on the tracked physical location of the real-world tool  2335  at a real-world implant position  2322 . The real-world XR image can include virtual guidance  2330  indicating a desired location of the virtual tool  2333  relative to the virtual anatomical structure  2320 . 
     After acquiring medical imagery from the patient, a 3D model reconstruction can be created. This model is presented in the user interface of the XR display. As shown in XR, the model is world-registered, (meaning that as the wearer of the display moves their head, the model remains in place) and, by default, located roughly half a meter above the patient. Fusing hand tracking with the XR system allows users to interact with the 3D model using their hands and performing gestures. This level of interaction allows the model to be used as a control interface for planning, navigation, and cross-platform hardware controls. The following are some examples of the possible applications for interacting with the anatomical view. 
     In some embodiments, the surgeon can interact with the anatomical view to determine stabilization options. Stabilization options can include whether the view is patient-stabilized (the content moves when the patient moves) or world-stabilized (the content remains still if the patient is moved). 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to determine view adjustments. For example,  FIGS. 24-25  illustrate that the surgeon can use their hands to rotate the model to get a better view from other angles or expand it to see in greater detail without leaning. 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to determine implant placement. Surgical implants can be planned or adjusted in 3D in addition to the existing 2D slice views and manipulations offered by GPS and similar software. 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to control tool navigation. 3D representations of tracked surgical tools are shown in the display relative in scale and pose to the patient anatomy and indicators can guide the surgeon to correct locations as dictated in the plans. 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to control a surgical robot. For example,  FIG. 26  illustrates that in robotic navigated surgeries, the surgeon  2390  can use hand gestures to select an individual implant  2610 ,  2620 ,  2626 ,  2630  on the XR 3D Anatomy View  2310  to direct the robot  2690  to move to the location for correct placement of that implant  2612 ,  2622 ,  2632 . In this example, virtual implants  2610  correspond to completed real-world implants  2612 ; virtual implant  2620  corresponds to a real-world implant  2622  that is currently being positioned, virtual implant  2630  corresponding to the next real-world implant  2632 ; and virtual implants  2626  that have been planned as part of the surgical procedure. 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to record or view an overview of the surgical process. In some examples, as illustrated in  FIG. 26 , surgeons can use hand gestures to select implants on the anatomical view and mark that as completed, giving the surgeon a visual representation of their overall progress. 
     In additional or alternative embodiments, the surgeon can interact with the anatomical view to select a 2D scan. For example, surgeons can view a gallery of 2D imagery organized by the location of the scan along the 3D model and use hand gestures to select them. 
       FIGS. 24-25  illustrate that using hand tracking the 3D Anatomical View can become interactive. Surgeons can use their hands to control and manipulate the view of the patient&#39;s anatomy to view the model in greater detail. In  FIG. 24 , by selecting a section of the view, the surgeon can expand on that region. Depending on the context, this expanded view can be used to plan placement of implants or navigate surgery in greater detail. In  FIG. 25 , the surgeon is able to rotate the expanded view through intuitive gestures. 
       FIG. 26  illustrates a surgeon using their hand to select the next planned implant location in the XR 3D Anatomy View, which signals the surgical robot to move to the next location. The real-world XR image also includes a progress overlay that indicates which implants have been completed, which implant site is currently being operated on, and which have yet to be started. For example, completed virtual implants may be displayed as black, virtual implants currently being operated on may be displayed in dark gray, and virtual implants that have not been started may be displayed in white. 
     Using the XR 3D Anatomy View for navigation, planning, and as an interactive menu offers several advantages. In some examples, using a 3D model derived from scans of the patient rather than generic models provides an accurate view of the patient that can be used for surgical planning and navigation. This also means that any 3D model can be used, derived from any kind of medical imagery, so the view can ultimately be used for any type of surgery. The view can be generated in advance or during surgery. 
     In additional or alternative embodiments, keeping the content world-registered prevents the error discrepancies of world- or object-registered alternate reality content from impacting the accuracy of XR-navigated surgery. This effectively allows the system to rely on accuracy from the tool tracking, just as it would for a 2D monitor display. 
     In additional or alternative embodiments, the immersion offered by XR and the ability to have a 3D view compared to the current method of using multiple 2D views will allow the surgeon to navigate in a more intuitive manner, which is particularly important for training new surgeons to perform navigated surgeries. 
     In additional or alternative embodiments, using world-registered content with world stabilized or patient-stabilized tracking instead of using head-registration stabilization allows the surgeon to use their head to lean in to get better views of the model without needing to manually manipulate it. This also allows anyone else watching the surgery with their own XR display to view the surgeon&#39;s interactions with it and reduces the chance users will experience motion sickness associated with large head-stabilized/registered displays. 
     In additional or alternative embodiments, because the content is world-registered instead of patient-registered, the surgeon can manipulate and move the model into a personalized position that is comfortable for them and select desired stabilization options. The surgeon can also rotate or expand the view itself as needed using intuitive hand gestures and easily return to the default or personalized position. 
     In additional or alternative embodiments, providing a 3D view above the patient, within the field of view of the surgical site, allows the surgeon to view the imagery and navigation in a way that is more comfortable and keeps them from needing to look away from the patient. In some embodiments, an XR headset with a wide field of view (e.g., the curved display screen  1302  of  FIG. 13 ) allows the surgeon to keep the 3D view in periphery vision. 
     In additional or alternative embodiments, because the imagery is located above the surgical site, from a ‘multi-player’ perspective, the surgeon is free to point at and explain patient anatomy to observers wearing an XR display with a lower chance of accidentally hitting or touching unsterilized surfaces or the patient. 
     In additional or alternative embodiments, the surgeon can plan, navigate, and control a surgical robot all through a single, intuitive display, drastically improving workflow. 
     In additional or alternative embodiments, interaction with the XR 3D Anatomy View in XR does not require physically touching a display, reducing sterility concerns and eliminating the difficulty posed by interacting with a touch display or mouse/keyboard with drapes over them. 
     Extended Reality Instrument Interaction Zone 
     Various operations that can be performed by the surgical system  2  to provide navigation assistance through a XR headset for a surgical tool during a medical procedure are now described with reference to the example embodiments of  FIGS. 27-32 . 
     In some embodiments, by combining motion tracking of surgical tools with head and hand tracking in extended reality, “interaction zones” can be used to hide, show, disable, and interact with elements of an augmented reality UI. These interaction zones can be sections of the 3D tracking volume that can be either predetermined or defined during a surgery using a tracked instrument and hand tracking controls. Using these interaction zones, surgeons can, for example, define region(s) where designated instruments should not be allowed during surgery, disable or hide the UI to prevent unintended actions, use the surgical instruments to interact with UI elements, and ignore tracking data from tools and hands from elsewhere in the OR. 
     In some embodiments, the interaction zone can be defined in real time. A surgeon or medical professional can move a surveillance marker relative to the patient and view its position in the XR headset. The position of this surveillance marker can be tracked and updated. A default box can be defined. Hand tracking controls can be used to modify the position. A fine tune control dial might also be available to adjust the locked position. The headset wearer can repeat this procedure until the wearer of the headset is satisfied, and edit it again later. The wearer of the headset will also have alternate hand controls to reorder locked positions into different boxes. One locked point may be part of more than one bounding box to define conjoined interaction regions. Locked points may be ordered into multiple boxes to define multiple interaction zones. Controls can be available to clear the region. Controls can be available to define which instruments should interact with the interaction zone. 
     In additional or alternative embodiments, interaction zones may be pre-configured by the software using relative measurements. For example, the user interface (“UP”) may only appear or allow interaction when hands or tools are above a certain height relative to the head. The default interaction zones can be adjusted in the UI settings. Once defined, the zones can be hidden, viewed faintly, or viewed contextually depending type and user settings. 
     Various embodiments herein describe using an interaction zones during a surgical procedure. Although the interaction zones are generally described individually, an XR headset can display multiple interaction zones that are independent and/or overlap. The following are just a few examples that can be used by a surgeon. 
     In some embodiments, an interaction zone can include a navigation zone. Extended reality displays can allow for minimally invasive, free-hand and robotically navigated surgeries. By creating a navigation zone near the patient, the surgeon can be guided using models in extended reality to an appropriate position and orientation according to a surgical plan, or create new plans based on current tool trajectory and position. A navigation zone can allow only tools within the zone to be navigated and used as a trigger to bring up the navigation display in extended reality. This also means tools detected outside of the navigation zone do not need to be tracked as accurately or at all, which can improve the performance of computer vision-based surgical tool tracking. 
       FIGS. 27A-B  illustrate an examples of a navigation zone used with 3D XR Anatomy  2750  associated with a real-world surgical procedure  2752 . Real-world tool  2754  is present within a real-world navigation zone  2790  in  FIG. 27B  and not within the real-world navigation zone  2790 . Accordingly, the XR display in  FIG. 27A  is a planning mode XR image  2710  and depicts a virtual planned tool  2712  at a planned location. In response to the a tracking system detecting the real-world tool  2754  being positioned within the navigation zone  2790 , planning mode XR image  2710  is replaced by navigation mode XR image  2730  as illustrated in  FIG. 27B . In navigation mode XR image  2730 , a virtual tool  2760  is displayed corresponding to the real-world tool  2754  along with a virtual planned tool  2712  to aid in moving the real-world tool  2754  with a defined navigation zone  2710 . 
     In some embodiments, an interaction zone can include a transition zone. Extended reality displays can pose the problem of displaying too much information, which can be especially problematic in large field-of-view displays and in settings where immediate action needs to be taken in a sensitive work area, such as a surgical table. It is important that surgeons are able to work without their vision being obstructed by UI elements. A particular region can be used to automatically collapse all UI elements when a tool or hands are brought into it, like a failsafe. The UI can be brought back by removing the tracked item from that area or by using another zone. Similarly, transition zones can be used to show or hide data depending on context, such as the aforementioned summoning of a navigation view and hiding a planning view when a tool is brought into the surgical region. (The navigation zone can be thought of as a specialized transition zone). 
     In some embodiments, interaction zones include exclusion zones. It may be critical that some regions of the operating environment are always clearly visible and never have XR overlays. An exclusion zone prevents UI elements from obstructing the view of the zone when seen from any angle. 
     In some embodiments, interaction zones include warning zones. If certain areas in the surgical space should be off limits to a tracked surgical robot or surgical tool, a warning zone can be defined. If one of these instruments crosses one of the bounding boxes that comprises the interaction zone, one or more configurable warning events will occur. When used with a surgical robot, a warning zone created by its projected path of motion can be displayed in 3D space in extended reality. The robot can also be forced to stop its motion when a tool, hand, or tracked headset obstructs its projected path, adding another degree of safety. The type of alert or warning that will be issued if an interaction zone is crossed will also be configurable. It can include beeps, XR occlusion, or textual warnings in the head set and monitor. 
       FIGS. 28A-B  show a warning zone  2880  defined by a surgeon. When the tool enters the warning zone  2880  in  FIG. 28B , a warning  2892  is displayed in the XR UI  2890  that the surgeon can dismiss. 
       FIGS. 29A-B  convey the real-world robot arm  2930  and a future location  2940  of the robot arm  2930  and a proposed path  2932  the real-world robot arm  2930  may move along to get to the future location. In  FIG. 29B  a tool  2920  is detected as moving into the proposed path  2930  and a warning message  2992  is added to the XR UI  2990 . In addition, when a tool enters the warning zone while the robot is in the middle of its movement, the robot stops or determines a new path to the future location. 
     In some embodiments, an interaction zone can include a tool selection zone. A designated region of the surgical tracking volume can be used for selecting which tools should be given focus by the UI. By placing a tool in the zone and having the surgeon confirm it (through the UI or even by simply orienting their head towards it for a moment), the surgeon can select which tool they are currently using. The extended reality display can then filter out tool info unrelated to the currently selected one and base robotic calculations on the selected tool&#39;s geometry. This simple tool selection zone ensures the surgeon only receives relevant data and keeps the extended reality area clean. 
     An example of the tool selection process is illustrated in  FIGS. 30A-C . In  FIG. 30A , the surgeon has passed their tool  3024  to their assistant. The UI  3090  still shows data for that tool  3024 , however, and does not show the surgeon&#39;s new tool  3022 . In  FIG. 30B , the surgeon brings the new tool  3022  into the selection zone  3020  and waits for the circle around the checkmark to complete, or uses a hand gestures to confirm the selection. In  FIG. 30C , the new tool  3022  has been registered. The UI data  3090  now shows the surgeon&#39;s tool  3022  and filters out data from the other tool  3024 . 
     In some embodiments, interaction zones include UI Zones. When tool tracking is used with extended reality displays, the UI itself can be altered by using the tool. Surgical tools can be used as a pen to write notes in 3D space, activate UI elements, place 3D models of screws and other surgical implants, rotate or move existing 3D models, or change shaders, among other uses. 
     In  FIGS. 31A-B , a 3D model  3110  generated using scans of the patient is shown with its own UI zone  3190 . As the surgeon brings the tool  3120  through the zone, they are able to “peel” away the external shader and instead view the 2D scan as a cross-section  3150 . They are able to do this from any angle as a way to quickly sort through the different cross-sections of the anatomical structure. 
     In another example of a UI zone illustrated in  FIG. 32 , a surgeon creates a UI zone  3290  to be used for sterile note taking during surgery. The surgical tool  3210  can be used as a virtual pen when brought into the defined UI zone  3290 . A tracked trigger point on the tool is used to indicate when to apply ‘ink’ or ‘lift off’ between words. Additionally, the tool can be used to select the image icon  3250  to trigger the camera on the XR headset to record an image than can be tied to the note. These aides could help surgeons in constructing their post-op notes. 
     An interaction zone is a section of the tracking volume that can be used to trigger extended reality UI changes or issue robotic commands. Some embodiments describe an approach to defining a 3D interaction zone and ascribes uses for them. 
     In some embodiments, creating interaction zones from the tracking volume allows for contextual interactions/changes in an XR interface or robotic control scheme. Using hand and tool tracking allows interaction zones to be defined and modified in a simplistic fashion in a sterile environment. Interaction zones can be user-defined using a tracked surgical instrument or hands, so additional implements are not required in the operating room. 
     In additional or alternative embodiments, interaction zones can be contextually defined by the XR software relative to tracked objects (for example, placing a navigation zone near a tracked patient reference point or a warning zone near a robot end effector). The interaction zones can be modified at any time, for example by showing the zones in XR and using pitch-points on the edges. 
     In additional or alternative embodiments, the interaction zones are practical in a surgical environment as safety precautions, allow for intuitive UI use, and can keep the UI region clean and the surgeon&#39;s view of the patient clear. 
     In some embodiments, interaction zones can have a variety of applications, and the type of interaction zone determines its behavior. For example, a navigation zone allows the UI to contextually provide navigation guidance to the user. It also aides object tracking algorithms by optimizing accuracy only for tools in the navigation zone. A transition zone gives the user the ability to have a clear view of the patient while offering a wealth of tools and functionality by revealing, hiding, or changing the UI when tracked objects are within them. They also limit the possibility that the surgeon may unintentionally active the UI while working. An exclusion zone prevents the XR user interface from obstructing the surgeon&#39;s view of critical regions. A Warning zone provides and extra level of awareness to the surgeon, avoiding unintended contact with the patient&#39;s body and insuring the path is clear for movement of surgical robots. For example, in free-hand surgeries, surgeons have little in the way of feedback when instruments are placed in dangerous positions. A Warning zone allows for immediate, easy to read feedback. A tool selection zone ensures that the UI is kept clean when multiple tools are being tracked. A UI zone allows for easy, intuitive use of the UI, allowing extended reality to fully realize its potential for surgical guidance. 
       FIG. 33  is a block diagram of an example of a surgical system  3300 . As depicted, surgical system  3300  includes an XR headset  3320 ; computer platform  910 ; camera tracking system  6 ,  6 ′; imaging devices; and surgical robot  800 . The computer platform  910  includes a tracking subsystem  830 , navigation controller  828 , XR headset controller  3330 , and an interaction zone controller  3390 . The tracking subsystem  830  can track a real-world pose of the XR headset  3320 , surgical robot  800 , and other real-world elements relative to a real-world coordinate system based on data from the camera tracking system  6 ,  6 ′. The navigation controller  828  can determine a difference between the real-world pose of real-world elements like a surgical tool and a planned location for the real-world elements. The XR headset controller  3330  can generate a real-world XR image for display by the XR headset based on a real-world pose of the XR headset such that the real-world XR image is tied to the real-world coordinate system. The interaction zone controller  3390  can determine a pose and type of interaction zones relative to the real-world coordinate system and provide information regarding the interaction zones to the XR headset controller  3330  for determining when a surgeon is interacting with an interaction zone. In some embodiments, a surgical system may include only a portion of these features. For example, a surgical system may include a XR headset  3320 , tracking subsystem  830 , and XR headset controller  3330 . 
       FIG. 34  is a flow chart of a process performed by a surgical system (e.g., surgical system  3300 ). At block  3410 , tracking subsystem  830  determines a real-world pose of a real-world element relative to a real-world coordinate system. In some embodiments, the tracking subsystem determines a real-world pose of a XR headset and a real-world pose of a real-world element. 
     At block  3420 , XR headset controller  3330  defines a portion of a real-world coordinate system as an interaction zone. In some embodiments, the headset controller defines the interaction zone to be one of a navigation zone, a transition zone, a warning zone, an exclusion zone, a tool selection zone, and a user interface (“UI”) zone. 
     In some embodiments, the surgical system further includes an interaction zone controller configured to define a dimension, a pose, and/or a type of the interaction zone based on a type and/or the real-world pose of the real-world element. 
     At block  3430 , XR headset controller determines whether the real-world element is within the interaction zone. 
     At block  3440 , XR headset controller  3330  determines user input based on tracking data of the real-world pose of the real-world element. 
     At block  3450 , XR headset controller  3330  generates a world-registered XR image based on the real-world pose of a XR headset. In some embodiments, the XR headset controller generates the world-registered XR image based on the real-world pose of the XR headset and the real-world pose of the real-world element. The world-registered XR image includes a virtual element that is generated based on a characteristic of the real-world element. The virtual element is posed based on the real-world pose of the XR headset and is displayed on the see-through display screen within a field of view of the user. In some embodiments, the XR headset includes a display with a wide field of view (e.g., the curved display screen  1302  of  FIG. 13 ), which allows the world-registered XR image to continue being displayed while the surgeon looks in slightly different directions. 
     In additional or alternative embodiments, the XR headset controller is configured to generate the world-registered XR image based on the real-world pose of the XR headset with the virtual element of the world-registered XR image displayed on the see-through display screen and with the virtual element being maintained at a constant pose relative to the real-world coordinate system regardless of the real-world pose of the XR headset. 
     In additional or alternative embodiments, the XR headset controller is configured to generate the world-registered XR image based on the real-world pose of the XR headset with the virtual element of the world-registered XR image being displayed on the see-through display screen and with the virtual element having a pose that is maintained to be a constant offset from the real-world pose of the real-world element regardless of the real-world pose of the XR headset. 
     In additional or alternative embodiments, the XR headset controller is further configured to determine user input based on tracking data of the real-world pose of the real-world element. The XR headset controller is further configured to generate the world-registered XR image further based on the user input. 
     In additional or alternative embodiments, the XR headset controller is configured to respond to a determination that the real-world pose of the real-world element is within the interaction zone by generating the virtual element within the world-registered XR image 
     At block  3460 , XR headset controller  3330  displays the world-registered XR image. In some embodiments, the world-registered XR image is displayed on a see-through display screen of a XR headset configured to be worn by a user during a surgical procedure. The see-through display screen can be configured to display the world-registered XR image and to allow at least a portion of a real-world scene to pass therethrough for viewing by the user. 
     In some embodiments, the XR headset controller  3330  is further configured to communicate with a navigation controller to receive navigation information from the navigation controller which provides guidance to the user during the surgical procedure on an anatomical structure. The XR headset controller is configured to generate the world-registered XR image to further include user interface (“UP”) data based on the navigation information for display on the see-through display screen. 
     In additional or alternative embodiments, the interaction zone is a navigation zone. The tracking system is further configured to only determine the real-world pose of the real-world element while it is within the navigation zone. The XR headset controller is configured to generate the world-registered XR image to contain the UI data associated with the virtual element corresponding to the real-world element in response to the real-world element being determined to be within the navigation zone. 
     In additional or alternative embodiments, the interaction zone is a transition zone. The XR headset controller is configured to generate the world-registered XR image to further exclude a portion of the UI data in response to the real-world element being determined to be within the transition zone. The XR headset controller is configured to generate the world-registered XR image to further include the portion of the UI data in response to the real-world element being determined to be outside the transition zone. 
     In additional or alterative embodiments, the interaction zone is a warning zone. The navigation controller is further configured to determine the warning zone includes a projected path of motion of a robot arm in the real-world coordinate system. The navigation controller is further configured to determine whether the real-world element is within the warning zone. In response to determining that the real-world element is within the warning zone, movement of the robot arm along the projected path is prevented. The XR headset controller is configured to generate the world-registered XR image such that a virtual path associated with the projected path of motion of the robot arm is displayed. The XR headset is further configured to output a warning to the user in response to the real-world element being within the warning zone. 
     In additional or alternative embodiments, the interaction zone is an exclusion zone and the XR headset controller is configured to generate the world-registered XR image such that view of the exclusion zone by the user is unobstructed by the XR image. 
     In additional or alternative embodiments, the interaction zone is a tool selection zone. The tracking system is further configured to determine whether a first real-world element is selected and/or deselected based on the first real-world element being determined to be within the tool selection zone. The tracking system is configured to determine the real-world pose outside of the tool selection zone of only real-world elements that are selected. 
     In additional or alternative embodiments, the interaction zone is a user interface (“UP”) zone. The XR headset controller is further configured to modify the world-registered XR image based on manipulation of the real-world pose of the real-world element in response to the real-world pose of the real-world element being determined to be within the UI zone. 
     In additional or alternative embodiments, the XR headset further includes a gesture sensor configured to output to the XR headset controller an indication of a hand gesture formed by the user. The XR headset controller is further configured to define and/or modify a dimension, a pose, and/or a type of the interaction zone based on the indication of the hand gesture formed by the user. 
     In additional or alternative embodiments, the surgical system further includes a surgical robot and a navigation controller. The surgical robot includes a robot base, a robot arm connected to the robot base, and at least one motor. The robot arm is configured to position an end effector which is configured to guide movement of a surgical tool. The at least one motor operatively connects to move the robot arm relative to the robot base. The navigation controller is configured to determine a target pose for the surgical tool based on a surgical plan defining where a surgical procedure is to be performed using the surgical tool on an anatomical structure and based on a pose of the anatomical structure. The navigation controller is further configured to generate steering information based on the target pose for the surgical tool, the pose of the anatomical structure, and the pose of the surgical tool. The steering information indicates where the surgical tool needs to be moved under control of the at least one motor. 
     In additional or alternative embodiments, the XR headset is a first XR headset configured to be worn by a first user during the surgical procedure and includes a see-through display screen configured to display a first world-registered XR image and to allow at least a first portion of the real-world scene to pass therethrough for viewing by the first user. The first world-registered XR image includes a first virtual element corresponding to the real-world element. The surgical system can further include a second XR headset configured to be worn by a second user during the surgical procedure and including a see-through display screen configured to display a second world-registered XR image and to allow at least a second portion of the real-world scene to pass therethrough for viewing by the second user. The second world-registered XR image including a second virtual element corresponding to the real-world element. The tracking system is further configured to determine a real-world pose of the first XR headset and a real-world pose of the second XR headset. The XR headset controller includes at least one XR headset controller and is further configured to generate the second world-registered XR image based on the real-world pose of the second XR headset. The first world-registered XR image and the second world-registered XR image are different. 
     Various operations from the flow chart of  FIG. 34  may be optional with respect to some embodiments of surgical systems and related methods. 
     FURTHER DEFINITIONS AND EMBODIMENTS 
     In the above-description of various embodiments of present inventive concepts, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of present inventive concepts. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which present inventive concepts belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense expressly so defined herein. 
     When an element is referred to as being “connected”, “coupled”, “responsive”, or variants thereof to another element, it can be directly connected, coupled, or responsive to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected”, “directly coupled”, “directly responsive”, or variants thereof to another element, there are no intervening elements present. Like numbers refer to like elements throughout. Furthermore, “coupled”, “connected”, “responsive”, or variants thereof as used herein may include wirelessly coupled, connected, or responsive. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Well-known functions or constructions may not be described in detail for brevity and/or clarity. The term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that although the terms first, second, third, etc. may be used herein to describe various elements/operations, these elements/operations should not be limited by these terms. These terms are only used to distinguish one element/operation from another element/operation. Thus, a first element/operation in some embodiments could be termed a second element/operation in other embodiments without departing from the teachings of present inventive concepts. The same reference numerals or the same reference designators denote the same or similar elements throughout the specification. 
     As used herein, the terms “comprise”, “comprising”, “comprises”, “include”, “including”, “includes”, “have”, “has”, “having”, or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof. Furthermore, as used herein, the common abbreviation “e.g.”, which derives from the Latin phrase “exempli gratia,” may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. The common abbreviation “i.e.”, which derives from the Latin phrase “id est,” may be used to specify a particular item from a more general recitation. 
     Example embodiments are described herein with reference to block diagrams and/or flowchart illustrations of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s). 
     These computer program instructions may also be stored in a tangible computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the functions/acts specified in the block diagrams and/or flowchart block or blocks. Accordingly, embodiments of present inventive concepts may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) that runs on a processor such as a digital signal processor, which may collectively be referred to as “circuitry,” “a module” or variants thereof. 
     It should also be noted that in some alternate implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Moreover, the functionality of a given block of the flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the flowcharts and/or block diagrams may be at least partially integrated. Finally, other blocks may be added/inserted between the blocks that are illustrated, and/or blocks/operations may be omitted without departing from the scope of inventive concepts. Moreover, although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. 
     Many variations and modifications can be made to the embodiments without substantially departing from the principles of the present inventive concepts. All such variations and modifications are intended to be included herein within the scope of present inventive concepts. Accordingly, the above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended examples of embodiments are intended to cover all such modifications, enhancements, and other embodiments, which fall within the spirit and scope of present inventive concepts. Thus, to the maximum extent allowed by law, the scope of present inventive concepts are to be determined by the broadest permissible interpretation of the present disclosure including the following examples of embodiments and their equivalents, and shall not be restricted or limited by the foregoing detailed description.