Patent Publication Number: US-2021169605-A1

Title: Augmented reality headset for navigated robotic surgery

Description:
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. However, existing navigation systems have limitations on usability and ergonomics for the surgeon, including 1) necessitating that the surgeon turn his/her head away from the patient and surgical instrument to view navigation information, 2) imposing reliance on other personnel to operate software functions of various equipment in the operating room, and 3) intermittent pauses with providing navigation during surgery while personnel and/or objects obstruct the ability of a tracking component to track poses of the patient, the robot, and surgical instruments. 
     SUMMARY 
     Various embodiments disclosed herein are directed to improvements in computer assisted navigation during surgery. An augmented reality (AR) headset is operatively connected to the surgical system and which can be configured to provide an interactive environment through which a surgeon, assistant, and/or other personnel can view and manipulate patient images, view and manipulate computer generated surgery navigation information, and/or control surgical equipment in the operating room. 
     Some embodiments of the present disclosure are directed to a surgical system that includes an AR headset, at least one AR headset controller, a tracking system, and surgical robot. The AR headset is configured to be worn by a user and has a display screen that is configured to display images for viewing by the user and to allow at least some ambient light to pass therethrough for viewing by the user. The tracking system is configured to determine a pose of an anatomical structure and a pose of an end effector and/or a surgical tool. The surgical robot includes a robot base, a robot arm connected to the robot base and configured to position the end effector which is configured to guide movement of the surgical tool, at least one motor operatively connected to move the robot arm relative to the robot base, and at least one navigation controller. The at least one 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 the anatomical structure and based on the pose of the anatomical structure, and 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. The steering information indicates where the surgical tool and/or the end effector need to be moved under control of the at least one motor. The at least one AR headset controller is operatively connected to the at least one navigation controller and to the display screen, and is configured to receive the steering information from the at least one navigation controller and to display a graphical representation of the steering information and/or the target pose for the surgical tool. 
     Various further embodiments are directed to apparatus and operations that enable a user to view and manipulate patient images, view and manipulate computer-generated surgery navigation information, and control surgical equipment such as imaging systems in the operating room. 
     Other surgical systems, AR headsets, and corresponding methods 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, AR headsets, and corresponding methods 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. 3  illustrates a camera tracking system component of 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 the 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 surgical planning computer which may be separate from and operationally connected to a surgical robot or at least partially incorporated therein 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 AR headsets operating in accordance with some embodiments of the present disclosure; 
         FIG. 13  illustrates an AR headset which is configured in accordance with some embodiments of the present disclosure; 
         FIG. 14  illustrates electrical components of the AR headset that can be operatively connected to a surgical robot and imaging devices in accordance with some embodiments of the present disclosure; 
         FIGS. 15-25  illustrate example views through the display screen of an AR headset in accordance with some embodiments of the present disclosure; and 
         FIGS. 26-31  illustrate example views through the display screen of an AR headset for providing navigation assistance for a surgical tool during a medical procedure 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 augmented reality (AR) 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. 
       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 MRI. 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 surgical system computer platform  900  of  FIG. 9  which includes the surgical robot  4  (e.g., robot  2  in  FIG. 1 ), a surgical planning computer  910 , and an image database  950  for storing image scans of patients. A surgeon reviewing the image scan(s) on a display device of the surgical planning computer  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  6 . The ability to mechanically couple surgical robot  4  and camera tracking system  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  6 . Surgical robot  4  may be positioned adjacent the patient at any suitable location to properly assist medical personnel. Camera tracking system  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  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 AR headset as will be explained in further detail below. The AR 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 AR 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 AR 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 AR headsets being worn by personnel in the operating room, the end effector, the surgical robot, a surgical tool in a navigated surgical procedure. The camera tracking system  6  or other 3D localization system is 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 AR headsets that may be used in conjunction with display  34  and/or a tablet or the AR head(s) may eliminate the need for use of the display  34  and/or tablet. 
     As illustrated in  FIGS. 3 and 5 , camera tracking system  6  works in conjunction with surgical robot  4  through wired or wireless communication networks. Referring to  FIGS. 1, 3 and 5 , camera tracking system  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 the structure upon which camera  46  is 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  6 . Camera body  36  may be made of the same material as robot body  8 . Camera tracking system  6  may communicate directly to an AR headset, tablet and/or display  34  by a wireless and/or wired network to enable the AR headset, tablet and/or display  34  to control the functions of camera tracking system  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  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  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  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  6  from moving during a medical procedure and may keep camera  46  from losing track of a DRA connected to an AR 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. 3 and 5 . This stability and maintenance of tracking enhances the ability of surgical robot  4  to operate effectively with camera tracking system  6 . Additionally, the wide camera base  38  may provide additional support to camera tracking system  6 . Specifically, a wide camera base  38  may prevent camera tracking system  6  from tipping over when camera  46  is disposed over a patient, as illustrated in  FIGS. 3 and 5 . 
     Camera telescoping support  40  may support camera  46 . In some embodiments, telescoping support  40  moves camera  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  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 camera  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 camera  46 . Camera  46  may be attached to lower camera support arm  42  by any suitable mechanism. Camera  46  may pivot in any direction at the attachment area between camera  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. 3 , 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. Camera  46  may be moveably disposed along curved rail  44 . Camera  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 camera  46  along curved rail  44 . As illustrated in  FIG. 3 , during a medical procedure, if an object prevents camera  46  from viewing one or more DRAs being tracked, the motors may responsively move camera  46  along curved rail  44 . This motorized movement may allow camera  46  to move to a new position that is no longer obstructed by the object without moving camera tracking system  6 . While camera  46  is obstructed from viewing one or more tracked DRAs, camera tracking system  6  may send a stop signal to an surgical robot  4 , AR headset, display  34 , and/or a tablet. The stop signal may prevent SCARA  24  from moving until camera  46  has reacquired tracked DRAs  52  and/or can warn an operator wearing the AR 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. 
       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 camera  46  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 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 camera  46  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). With robotic navigation, various processing components and associated software described below are provided that enable pre-operatively planning of 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 surgical procedure. 
     Various embodiments below are directed to using one or more AR 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  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 AR headset(s)  920 , display  34  and/or light indicator  28 . The AR headset(s)  920  are each configured to display images on a see-through display screen to form an augmented 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 AR 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 AR 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 AR 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 AR 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 AR 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 AR 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  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. A navigation controller  828  located in the tracking subsystem  830  and/or the in the computer  822  of the computer subsystem  820  can be configured to determine the poses, e.g., location and angular orientation of the tracked DRAs. The navigation controller  828  can use the determined poses to control movement of the end effector  26  and/or to control display of various graphical objects on the display  824 , e.g., display screen of one or more AR headsets  920 . For example, as will be explained below the navigation controller  828  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 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 surgical planning computer  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 a surgical system computer platform  900  that includes a surgical planning computer  910  which may be separate from and operationally connected to a surgical robot  4  or at least partially incorporated therein according to some embodiments of the present disclosure. Alternatively, at least some operations disclosed herein as being performed by the surgical planning computer  910  may additionally or alternatively be performed by components of the surgical robot  4  such as by the computer subsystem  820 . 
     Referring to  FIG. 9 , the surgical planning computer  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 AR 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  of patient medical images, components of the surgical robot  4 , and/or other electronic equipment. 
     When the surgical planning computer  910  is at least partially integrated within the 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 AR 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 AR 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, 3 GPP 4G and/or 5G (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 by a surgical planning computer. 
     The processor  914  can operate to display on the display device  912  and/or on the AR 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 AR headset  920 , the AR 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 AR headset  920  as will be explained in further detail below. 
     The surgical planning computer  910  enables 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 be involve human input or assistance. This surgical planning computer  910  allows an operator to choose the correct implant for a patient, including choice of size and alignment. The surgical planning computer  910  enables 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 the surgery, the surgeon will choose which cut to make (e.g. posterior femur, proximal tibia etc.) using a computer screen (e.g. touchscreen) or augmented reality interaction (e.g., hand gesture based commands and/or voice based commands) via, e.g., the AR headset  920 . The surgical robot  4  may automatically move the end effector  26  to a target pose so that the surgical tool is aligned with a target location to perform a surgical procedure on an anatomical structure. 
     In some embodiments, the surgical system computer platform  900  can use two DRAs to tracking patient anatomy position: one on patient tibia and one on patient femur. The platform  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 platform  900  could address this problem by using the AR headset  920  to display a three-dimensional 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 surgical planning computer  910  and which can be manipulated by a surgeon while viewed through the AR 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 AR headset  920 . 
     For example, the surgeon can be operationally displayed a virtual handle to grab and move the implant to a desired pose and adjust planned implant placement. Afterward, during surgery, the platform  900  could display navigation graphical information through the AR 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 in the anatomical structure. When the surgical procedure involves bone removal, the progress of bone removal, e.g., depth or cut, can be displayed in real-time through the AR headset  920 . Other features that may be displayed through the AR 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 surgical planning computer  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 surgical planning computer  910  and/or the surgical robot  4  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 AR headset  920  and/or another display device of the surgical planning computer  910 , the surgical robot  4 , and/or another component of the surgical system  2 . 
       FIG. 12  illustrates a block diagram view of the components of a surgical system that include a pair of AR headsets  1200  and  1210  (head-mounted displays HMD1 and HMD2), which may correspond to the AR 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 AR headsets  1210  and  1210 , respectively. It is optional for the assistant  612  to wear the AR headset  1210 . The AR 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 AR based environment may eliminate a need for the tech  614  to be present in the operating room and may eliminate a need for use of the display  34  shown in  FIG. 6 . Each AR 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 , AR headset  1200  has a field-of-view (FOV)  1202  for tracking DRAs and other objects, AR headset  1210  has a FOV  1212  partially overlapping FOV  1202  for tracking DRAs and other objects, and the navigation camera  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 AR headsets and/or the navigation camera  46  may view and track the DRA on another one of the AR headsets to enable the tracking subsystem  830 , the navigation controller  828 , and/or an AR headset controller ( 930  in  FIG. 14 ) to determine the pose of the AR headset. 
     The AR 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 AR Headset Components and Integration to Surgical Robot and Other Equipment 
       FIG. 13  illustrates an AR headset  920  which is configured in accordance with some embodiments of the present disclosure. The AR headset includes a headband  1306  configured to secure the AR headset to a wearer&#39;s head, and includes a display screen  1302  and an electronic component enclosure  1304  supported by the headband  1306 . 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. 
       FIG. 14  illustrates electrical components of the AR headset  920  that can be operatively connected to the surgical robot  800  and imaging devices, such as the C-arm imaging device  104 , the O-arm imaging device  106 , and/or the image database  950  in accordance with some embodiments of the present disclosure. 
     The AR headset  920  provides an improved human interface for performing navigated surgical procedures. The AR headset  920  can be configured to provide functionalities that include, without limitation: identification of hand gesture based commands and/or voice based commands, AR graphical objects are displayed as an overlay which can be displayed anchored to particular real-world objects viewed through the display screen  1450 , and associated optics, multiple display regions, viewing video feeds from cameras mounted to one or more AR headsets  920  and other cameras, surgical light (in-built or otherwise connectable), microphones, etc. 
     Electrical components of the AR headset  920  can include one or more cameras  1440 , a microphone  1442 , a gesture sensor  1444 , a pose sensor (e.g., inertial measurement unit (IMU))  1446 , a display module  1448 , and a display screen configured to display images for viewing by the wearer and to allow at least some ambient light to pass therethrough for viewing by the wearer. The one or more cameras  1440  may be configured operate as the gesture sensor  1444  by enabling identification of and based gestures are 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 physical contact, e.g. tapping on the enclosure  1304 . The pose sensor  1446 , e.g., IMU, may include a multiaxis accelerometer, a tilt sensor, and/or another sensor that can sense rotation and/or acceleration of the AR 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 tracking system, e.g.,  6  in  FIG. 12 and/or 830  in  FIG. 8 , and a surgical robot  4 . The tracking system is configured to determine a pose of an anatomical structure and a pose of an end effector and/or a surgical tool. The surgical robot  4  includes one or more navigation controllers e.g.,  828  in  FIG. 8 , that are configured to determine a target pose for the surgical tool based on a surgical plan, e.g., from the surgical planning computer  910  of  FIG. 9 , defining where a surgical procedure is to be performed using the surgical tool on the anatomical structure and based on the pose of the anatomical structure. The one or more navigation controllers are 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, the steering information indicating where the surgical tool and/or the end effector need to be moved under control of the at least one motor. 
     The electrical components of AR headset  920  are operatively connected to the electrical components of the surgical robot  800  through a wired/wireless interface  1452  that communicates with a wired/wireless interface  1460 , e.g., connection panel  808  in  FIG. 8 , of the surgical robot  800 . The electrical components of AR headset  920  may be operatively 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 other medical equipment through the wired/wireless interface  1452 . 
     The surgical system  2  further includes at least one AR headset controller  1430  (also referred to as “AR headset controller” for brevity) that is operatively connected to the at least one navigation controller  828  (also referred to as “navigation controller” for brevity) and to the display screen  1450 . The AR headset controller  1430  is configured to receive the steering information from the navigation controller  828  and to display a graphical representation of the steering information and/or the target pose for the surgical tool. As illustrated in  FIG. 14 , the AR headset controller  1430  may be a component of the AR headset, the surgical robot  800 , and/or another component of the surgical system  2 . 
     The display screen  1450  is configured to display objects through an optical system in a manner such that when the wearer looks therethrough, the object appears to be displayed in the real world. The optical system can be positioned by the headband  1306  directly placed in front of the wearer&#39;s eyes. Various functionality is provided by software executed by the AR headset controller  1430  which can reside in the AR headset  920  and/or in an external component connected via wired cables and/or wireless communication links. 
     Example Wearer Views Through the AR Headset 
       FIGS. 15-25  illustrate example views provided to the wearer through the display screen  1450  of the AR headset  920  in accordance with some embodiments of the present disclosure. 
     One potential drawback of using an AR headset in an operating room is the potential for bright ambient lighting to “wash-out” or reduce the contrast of displayed objects. These potential drawbacks can be reduced or eliminated by some embodiments described below where the display screen  1450  is configured to have horizontal bands of differing light transmissivity and/or where attachable components of varying size adjust opacity of the user&#39;s view through the display screen  1450 . These darkened band(s) of the optical system can function to increase the contrast of displayed objects to, for example, enable a surgeon to more accurately view medical radiographs. 
     In one illustrative embodiment, the see-through display screen  1450  is configured with at least two laterally extending bands, where an upper one of the at least two laterally extending bands has a lower light transmissivity, e.g., darker, than a lower one of the at least two laterally extending bands which constrain incident ambient light passing therethrough for viewing by the user. The at least one AR controller  1430  can be configured to display two dimensional images in the upper one of the at least two laterally extending bands and to display a three dimensional model of the anatomical structure provided by the at least one navigation controller  1430 . 
     The AR headset user interface further enables sterile software control and salient display of information features that address limitations of current navigation technology. Additionally, as described below, operational functionality is provided that enables wearers to virtually interact with navigation elements using hands, surgical instruments, and/or other objects. 
     The AR headset operations can display both 2D images and 3D models in the different bands. The 2D images may preferably be displayed in a more opaque band (upper band of the display screen optics) and the 3D model may be more preferably displayed in the more transparent band, otherwise known as the environmental region (bottom band of the display screen optics). Below this band where the display screen optics end, the wearer has an unobstructed view of the patient. It is noted that the separate bands are fluidic. It is possible that the 3D content moves to the opaque band depending on the position of the headset relative to the content, and 2D content can be placed in the transparent band and stabilized to the real world. Additionally, the entire display screen optics can be darkened to convert the headset into virtual reality for surgical planning or completely transparent during the operation. Any of the controls can be found in any of the band depending on the wearer&#39;s preference. 
       FIG. 15  illustrates two laterally extending bands across the display screen  1450  that are divided along dashed line  1500 . Although not illustrated by shading in  FIG. 15 , it is to be understood that the upper one of the at least two laterally extending bands has a lower light transmissivity (e.g., darker shading) than a lower one of the at least two laterally extending bands to reduce the amount of incident ambient light passing therethrough for viewing by the user. The at least one AR controller  1430  has displayed a plurality of two dimensional images in screen areas  1510  and  1512  within the upper one of the at least two laterally extending bands. The at least one AR controller  1430  has also displayed a three dimensional model of the anatomical structure in another screen area  1520  in the lower one of the at least two laterally extending bands, and displayed implant information  1530  identifying characteristics of a planned implant that is to be used in a surgical procedure. Displayed implant information  530  identifies that a CEO threaded screw having diameter 5.5 mm and length 43 mm is planned to be implanted in spine location L2-L. 
       FIGS. 16-19  illustrate example operations for a wearer to interact with various objects that are displayed on the display screen  1450  of the AR headset  920 . 
     The AR headset  920  can be configured to provide hand-tracking which enables the wearer to naturally and in a sterile-fashion interact with software functionality of the surgical system  2 . These operations may be provided through processing of the video streams from the camera(s)  1440  of AR headset  920 . The AR headset controller  1430  can be configured to identify and respond to a plurality of different hand based gestures, including but not limited to pinching, pushing, hand-signals, pre-defined motions (hand flipping). 
     The wearer can access different menus and sub-menus and perform specific functions, such as menu selection, menu manipulation/re-positioning, image manipulation/re-positioning, and virtual projection manipulation/re-positioning. An example recognizable hand gesture can be pinching, which can be formed by the thumb and index finger connected with the other three fingers raised (shown in  FIG. 16 ). Specifying a specific hand gesture reduces the chance of false-positives when interacting with the gesture recognition functional software, especially in the operating room where a user will need to occasionally rest hands in the field-of-view of the camera(s)  1440 . Hand gestures can be performed with either hand or both hands. Hand-tracking functionality may be displayed to the surgeon by augmenting different hand models over the hands (glove, mesh, ball-and-stick model). 
     In one embodiment, the gesture sensor  1444 , which can include the camera(s)  1440 , is configured to output to the AR headset controller  1430  an indication of a hand gesture formed by the user. The AR headset controller  1430  is configured to control graphical objects displayed on the display screen  1450  responsive to recognition of the hand gesture. 
     As explained above, the gesture sensor  1444  can include the camera(s)  1440  mounted to face away from the user to output a video stream of the user&#39;s hand while positioned in front of the AR headset  920  within a field-of-view of the camera(s)  1440 . The AR headset controller  1430  can be configured to associate different recognizable hand gestures to different ones of a plurality of operations that control the graphical objects displayed on the display screen  1450 . The plurality of operations may include at least one of the following: user command to expand a menu item  1530  in that is displayed on the display screen into a list of sub-menu items that are then displayed on the display screen; user command to select a menu item and/or one of a plurality of sub-menu item that is displayed on the display screen; and user command to operationally control size, location, and/or orientation of one of the graphical objects that is displayed on the display screen. 
     The AR headset controller  1430  can be configured to display a computer generated hand model on the display screen with a pose that is dynamically updated to track a present pose of the user&#39;s hand identified in the video stream from the camera. 
     In a further embodiment, the AR headset controller  1430  is configured to associate a recognizable hand gesture to a command to select a surgical implant from among a set of surgical implants that can be used for implantation into the anatomical structure, and to display a graphical representation of the surgical implant that is select on the display screen  1450 . In another embodiment, the AR headset controller  1430  is configured to associate different recognizable hand gestures to different ones of a plurality of operations by the surgical system, where the plurality of operations includes at least one of the following: command to control imaging of the anatomical structure by an imaging system; command to control which of a plurality of images of the anatomical structure is displayed on the display screen; and command to control movement of the robot arm of the surgical robot relative to the anatomical structure. 
     In  FIG. 16 , the AR headset controller  1430  has displayed a plurality of images in screen areas  1620 ,  1630 , and  1640 . In screen area  1620  the AR headset controller  1430  has rendered a computer generated hand model  1622  of the user&#39;s hand forming a pinch gesture displayed as a graphical overlay on video of a real-world object  1610 , e.g., anatomical structure that resides on a table and viewed by the camera(s)  1440 . The recognized pension gesture may be used to select among user selectable indicia display along a navigation bar  1600  under control location, size, and/or other characteristics of the screen areas  1620 ,  1630 , and  1640 . 
     Typically, surgeons also wear helmets with attached surgical headlights to improve visualization of the patient. In one variant, the headlight can be part of the AR headset  920  or connected thereto. The AR headset  920  may be configured to control the brightness setting of the light via an external control or through AR controls that include gesture-based command recognition and/or voice based command recognition. 
     The AR headset wearer may use gesture-based commands and/or voice based commands, which are identifiable by the AR headset controller  1430 , to change characteristics of a surgical tool and/or an implant device. For example, a surgeon may say “Change screw length to 6.5” to cause the screw length that is displayed in the display screen  1450  to be changed to indicate a size, shape, and/or pose that correspond to the requested screw length. 
     Augmented Navigation Operations 
     The AR headset user interface further enables sterile software control and salient display of information features that address limitations of current navigation technology. Additionally, as described below, operational functionality is provided that enables wearers to virtually interact with navigation elements using hands and surgical instruments. 
       FIG. 17  depicts what a wearer may see through the display screen  1430 . In the upper band, the software displays images for navigation, the standard being axial and sagittal views for spine navigation, but any and multiple 2D planes can be shown, such as the coronal plane (depicted in  FIG. 16 ). These images could be modified based on the needs of different procedures, such as arthroplasty. The images can be zoomed into and panned by the use of hand gestures. Additional views can be accessed through a displayed dropdown list  1710  via hand gestures. The wearer can select the digital loupes view as well as an image gallery from among the list  1710 . In this gallery, the wearer is able to view images and manipulate images associated with the patient. For three dimensional (3D) images such as MRI/CT scans, the wearer can scroll through the slices using hand gestures. By selecting the two dimensional (2D) tab, the 2D images appear/disappear. By selecting the 3D tab, the 3D reconstructed model appears/disappears. 
     In the example of  FIG. 17 , the controller  1430  has displayed a plurality of images in screen areas  1700 ,  1702 , and  1704 . The user is using a pinch gesture to select a menu item (e.g., coronal image view) from among a plurality of many items  1710  (listing of available image views including standard, coronal, loupes, and gallery) being displayed on the display screen  1450 . 
     Referring to  FIG. 18 , the AR headset operations also allow the wearer to modify image properties within the display area  1800 , such as window/level and the slicing type (orientation). The wearer can perform these modifications through selectable settings indicia  1810  illustrated in the example view of  FIG. 18 . 
     Referring to  FIG. 19 , when 3D is enabled, a 3D graphical representation of the spine is obtained (which is based on imaging scans) and displayed on the display screen  1450  above the patient. This graphical representation may be configured by the AR headset controller  1430  to be the same size and oriented to have the same pose as the patient&#39;s actual anatomy or may be configured to be larger-to-scale, such as 2:1 for enhanced visualization. The graphical representation may be anchored to a location as determined based on a particular navigated reference array, in this case the patient reference array. This anchoring, or world/environment-stabilization may be performed through a combination of both inside-in and outside-in tracking. 
     An IMU  1446  of the AR headset  920  can be configured to measure the relative orientation of the AR headset  920  (inside-out tracking). The navigation camera  46  of the camera tracking system  6  can be used to track a reference array on the AR headset  920  to measure pose, position and angular orientation, (outside-in tracking). This data can be used to update the projection of the display 3D graphical representation as the wearer&#39;s head moves, providing the perception to the wearer that the graphical representation has remained stationary. This type of effect may also be achieved through simultaneous localization and mapping (SLAM) techniques. 
     In one embodiment, a plurality of the cameras  1440  are spaced apart and mounted to face away from the user. The tracking system  830  is operative connected to process video streams from the plurality of cameras  1440  and configured to determine a pose of the anatomical structure and a pose of the end effector and/or the surgical tool. The tracking system  830  can be further configured to process the video streams from the plurality of cameras  1440  to determine pose of a reference array connected to the anatomical structure and pose of a reference array connected to the end effector and/or the surgical tool. 
     In still a further embodiment, the tracking system  830  processes a video stream from the navigation camera  46  of the camera tracking system  6  to determine pose of a reference array connected to the AR headset  920 . The AR headset controller  1430  can be configured to control a pose and scale of a three dimensional model of the anatomical structure that is displayed on the display screen  1450  based on the pose of the reference array connected to the anatomical structure and the pose of the reference array connected to the AR headset. The pose sensor  1446  of the AR headset  920  can be configured to output a sensed pose of the AR headset  920 , and the AR headset controller  1430  can be operatively connected to the pose sensor  1446  and further configured to control a pose of a three dimensional model of the anatomical structure that is displayed on the display screen  1450  based on the pose of the reference array connected to the anatomical structure and the sensed pose of the AR headset  920 . 
     This allows the wearer&#39;s head to move to look at different perspectives of the anatomy. The location and orientation of the graphical representation relative to the anchor can be moved dependent on the wearer&#39;s preference and can even be overlaid over patient anatomy. Additionally, in this particular example, the graphical representation is illustrated as being a solid surface, offering enhanced visualization of the surface. In different variants, the graphical representation may be a mesh to allow visualization of inside the anatomical structure, e.g, bone. This 3D graphical representation ultimately provides a more intuitive navigation setup for the wearer instead of on 2D images that burden the wearer to attempt to mentally visualize the 3D anatomical structure. 
     Referring to  FIG. 20 , when a surgical tool  2002  is brought in vicinity of a tracked anatomical structure and within the field of view of the cameras  1440  ( FIG. 14 ) and  46  ( FIG. 6 ) tracking a reference array  2030  and  2032  connected to the surgical tool  2002 , a graphical representation  2000  of the tool can be displayed in 2D and/or 3D images in relation to a graphical representation  2010  of the anatomical structure. A wearer can use the viewed graphical representations to adjust a trajectory  2020 , which can be illustrated as extending from the graphical representation  2000  of the tool through the graphical representation  2010  of the anatomical structure. This operation may be performed through the displayed or through a control command, e.g. button, on the instrument. Note that this can be done with the instrument interfacing the patient or the instrument interfacing with the 3D model itself. 
     Once a screw trajectory is set, its dimensions (length, width), orientation, and depth can be modified using hand gestures, such as the pinch gesture shown in  FIGS. 20 and 21 . The trajectory can also be adjusted in the 2D images as well, as shown in  FIG. 22 . For example, in  FIG. 22  a wearer has formed a hand gesture, e.g., pinch, that is interpreted as a command to select a smaller size type (e.g., smaller diameter and/or length) of screw which is then updated in the graphical representation  2210  of the screw shown as an overlay on the medical image  2200  and/or displayed in another graphical area  2202 . Note that in these examples, a screw is used as the implant, but the implant can alternatively include but not limited to spacers, rods, and prostheses. 
     Referring to  FIG. 23 , once the trajectory is set, when another navigated tool  2300  comes within vicinity of the planned trajectory  2020  of the tool  2002  (illustrated as object  2000 ), an augmented trajectory guidance interface is displayed to help the wearer position the tool  2300  to the same trajectory  2020 . In a particular example of  FIG. 23 , a graphical indicator  2306  appears instructing which direction to move the instrument  2300  until the outer circle  2302  aligns with the inner circle  2304 . Once these circles  2302  and  2304  are aligned, the wearer can then be instructed to push the instrument  2300  down into the patient until the circles  2302  and  2304  are aligned (e.g., become concentric), thus indicating the target depth is reached. There are other possible approaches to this trajectory guidance, including but not limited to arrows pointing towards the desired trajectory and color gradients. Once the implant is placed, the wearer can select and move to a next step of the operation procedure. 
     Referring to  FIG. 24 , the system operational functionality can enable a plurality of the AR headsets to be used in defined combined operational modes, including any one or more of: a collaboration mode, a teaching mode, and an independent mode. In a collaboration mode, a secondary wearer wearing a second AR headset has the ability to interface through the second AR headset to the control the display interface of a first AR headset worn by a primary wearer. As shown in Error! Reference source not found., the secondary wearer sees the same 3D model and relevant controls stabilized to the environment that is second by the primary wearer, the only difference being the content is flipped to be legible from his/her perspective. The secondary wearer can perform all trajectory modification actions as described previously which will update the primary wearer&#39;s view through the first AR headset. In teaching mode, the primary wearer can change his/her view that is provided through the first AR headset to the second AR headset for viewing by the secondary user, such as to enable the second AR headset to display the images/scans from the perspective of the secondary wearer, and vice-versa. In independent mode, the views provided by the first and second AR headsets are controlled independent of each other, which enables the two wearers to perform independent navigation simultaneously. 
     For example, in one embodiment the surgical system  2  includes first and second AR headsets. At least one AR headset controller, one of which may reside in the first AR headset, is operatively connected to receive a first video stream from the camera of the first AR headset and configured to selective route the first video stream to the display device of the first AR headset and/or to the display device of the second AR headset responsive to electronic commands obtained from a user wearing the first AR headset. The least one AR headset controller, one of which may reside in the second AR headset, is operatively connected to receive a second video stream from the camera of the second AR headset and configured to selective route the second video stream to the display device of the first AR headset and/or to the display device of the second AR headset responsive to electronic commands obtained from a user wearing the second AR headset. 
     Referring to  FIG. 25 , the at least one AR headset controller can be configured to display notifications and warnings to the wearer within his/her field-of-view. Such warnings can inform, for example, that the patient reference array has moved, navigation integrity is lost, one or more reference arrays cannot be seen, potential for robot collision is predicted, etc. These notifications may be displayed on the display screen  1450  with or without affecting the operation of the user interface provided through the AR headset  920 . 
     As explained above, the AR headset  920  and associated operations not only support navigated procedures, but also can be performed in conjunction with robotically assisted procedures. In the latter case, the pre-operative plan is loaded from the surgical planning computer  910 . The software shows the wearer the entire plan in 3D with the planned implants. The wearer can select the screw or provide adjustment to a surgical plan. Once the plan is finalized, the wearer through either the AR interface, foot-pedal, or other controls moves the robot onto the planned trajectory to guide placement of additional tools. 
     Surgical Tool Navigation Operations Using AR Headset 
     Various operations that can be performed by the surgical system  2  to provide navigation assistance through AR headset for a surgical tool during a medical procedure are now described with reference to the example embodiments of  FIGS. 26-31 . 
     Some embodiments may enable an AR headset wearer to accurately navigate a surgical tool to a target vector location within the reference space using AR overlaid 3D navigation objects, also referred to as an iron sight. The overlaid 3D navigation objects can provide amplified visual feedback to enable a wearer to correct tool depth, angle, and tip position relative to the operative navigation trajectory. 
     A surgeon can plan a trajectory, e.g., via the surgical planning computer  910 , that defines a specific vector position on a patient anatomical image. The image is localized to a patient static reference array which carries over the position of the vector. The patient static reference array is tracked by the cameras and compared to another tracked array connected to a surgical tool. 
       FIG. 26-28  illustrates graphical objects that can be displayed on the display screen of the AR headset to provide navigation assistance for positioning a surgical tool. The graphical objects include elongated objects, lines, circles, text, and other indicia that are displayed in relative positions that indicate planned versus present poses (e.g., position and angular orientation) of the surgical tool. This embodiment can provide assistance with trajectory in general positioning for the surgical tool in relation to a planned location on the anatomical structure. 
     As shown in  FIG. 26 , the depiction of the present tool position is not aligned properly in terms of trajectory with the planned position, such that the distal end of the tool is off trajectory from the planned position. The circles on the right side of the image provide the following indications. A small circle  2600  indicates the planned tool tip position, and is surrounded by a medium-size circle  2604  indicating the overall tool trajectory and position of the distal end of the tool. The circle  2602  to the right indicates the present position of the tool, which illustrates that the proximal end of the tool is closer in proximity to the planned position while the distal end of the tool is off axis or off trajectory. 
     Corresponding operations by the AR headset controller  1430  can include to display on the display screen  1450  a graphical representation of the target pose for the surgical tool and display on the display screen  1450  a graphical representation of the pose of the surgical tool. The AR headset controller  1430  can be configured to determine a trajectory offset distance between where a planned trajectory of the target pose for the surgical tool intersects a target location on the anatomical structure and where a trajectory of the pose of the surgical tool intersects the target location on the anatomical structure. 
     The AR headset controller  1430  can be configured to display each of the graphical representations of the target pose for the surgical tool and the pose of the surgical tool as elongated objects  2610  and  2620  (e.g., rectangular lines) each having a major axis extending between opposite ends, and control spacing between where one end of the elongated objects are displayed on the display screen responsive to the trajectory offset distance. For example, as shown in FIG.  26 , object  2610  can indicate a planned pose of the surgical tool and object  2620  can indicate a present pose of the surgical tool. 
     The AR headset controller  1430  can be configured to control an angle of incline between the elongated objects  2610  and  2620  displayed on the display screen responsive to an angle between the planned trajectory of the target pose for the surgical tool and the trajectory of the pose of the surgical tool. 
     The AR headset controller  1430  can be configured to display each of the graphical representations of the target pose for the surgical tool and the pose of the surgical tool as circular objects  2602 - 2604  and control spacing between centers of the circular objects displayed on the display screen responsive to the trajectory offset distance. 
     The AR headset controller  1430  can be configured to display the graphical representations of the target pose for the surgical tool and the pose of the surgical tool as objects that are spaced apart by a distance indicating an offset from a tip of the surgical tool to the target location on the anatomical structure. 
       FIG. 27  illustrates that the proximal tips of the planned and present locations of the surgical tool overlap, while the present pose  2620  of the surgical tool is inclined relative to the planned pose  2610 . 
     Using the visual navigation information, the wearer moves the tool toward the planned pose, and as the present pose converges toward the planned pose, the convergence causes the displayed circles to converge become concentric with each other. As the circles overlay, the sensors correspondingly become more filled, such as shown in  FIG. 28 .  FIG. 28  further illustrates that the proximal tips of the planned and present locations of the surgical tool overlap, and that the present pose of the surgical tool is coincident with the planned pose, such that the present pose of the surgical tool is accurately aligned with the planned pose. 
     In some additional or alternative embodiments, the AR headset controller  1430  is configured to display the graphical representations of the target pose for the surgical tool and the pose of the surgical tool relative to three orthogonal axes representing a three dimensional space. The AR headset controller  1430  controls spacing between where the graphical representations are displayed along a first one of the three orthogonal axes responsive to a depth offset distance between a tip of the surgical tool and the target location on the anatomical structure. The AR headset controller  1430  also controls spacing between where the graphical representations are displayed along a plane formed by a second and third one of the three orthogonal axes responsive to the trajectory offset distance between where a planned trajectory of the target pose for the surgical tool intersects a target location on the anatomical structure and where a trajectory of the pose of the surgical tool intersects the target location on the anatomical structure. 
     This embodiment uses more data from the camera(s) tracking reference arrays to include depth tracking of the surgical tool in addition to general spatial data. This allows for greater accuracy of navigation to be provided to the wearer as the surgical tool is moved to the planned pose for the surgical procedure. An example flow of operations can include taking the position and angle data from one or more cameras, and projecting the data for display through the display screen  1450 . In the illustrated example of  FIG. 29 , a planned tool trajectory line  2900  is displayed along with three depth circles  2910 ,  2912 , and  2914 . Depth circle  2910  indicates a present depth of a reference array  2930  connected to a surgical tool  2932 , relative to the depth circle  2912  indicating a present depth of a tip of the surgical tool  2932 , and relative to the depth circle  2914  indicating a planned maximum insertion depth of the tip of the tool  2932 . Offset circles  2920  and  2922  are displayed which indicate an offset between a reference array  2930  attach to a surgical tool  2932  and the planned tool trajectory line  2900 . 
     An objective of the illustrated navigation operation is to visually amplify the depth, angle, and tooltip position correction so that the wearer can more accurately lineup the tool to the planned trajectory  2900  and then navigate the tool downward to the planned maximum insertion depth within the anatomical structure. The displayed offset circles  2920  and  2922  are dynamically modified to indicate that the offset between the tool tip and tool of the tool relative to the trajectory  2900  is decreasing as the tool is moved closer to the planned trajectory  2900 . After the tool become sufficiently aligned with the planned trajectory  2900 , the wearer then moves the tool downward along the trajectory  2900  until the depth circles  2912  and  2914  converge at the planned maximum insertion depth. 
       FIG. 30  illustrates a graphic representation of an anatomical structure  3000 , e.g., spinal vertebra, and the present position of a tool  2932  relative to a planned tool trajectory  2900 . The offset circles,  2920  and  2922  and depth circles  2912  and  2914  of  FIG. 29 , are also illustrated in  FIG. 30  providing navigation guidance to the wearer for moving the tool  2932  to become aligned with the planned tool trajectory  2900 . The present tool tip position is illustrated as coinciding with the planned tool trajectory  2900 , i.e., the tip location or lower depth rings can be seen to be in the correct position whereas the upper rings are shown to be offset. 
       FIG. 31  illustrates a subsequent view of the graphic representation of the anatomical structure  3000  after the wearer has moved the tool  2932  to become aligned with the planned tool trajectory  2900 , such that offset circles of  FIG. 29  have become concentric. The surgeon can then move the tool  2932  downward along the planned tool trajectory  2900  until the depth circles of  FIG. 29  are aligned. 
     The offset circles and/or depth circles may be rendered using color coding, e.g. changing from red to green, as they become aligned with proper positioning. 
     Cross-Platform Integration of Medical Devices Using AR Headset(s) 
     Various further embodiments are directed to providing cross-platform integration of medical devices using one or more AR headsets. These operations may avoid a medical personnel feeling the need to remove the AR headset in order to perform certain actions with one or more medical devices and the operating room, such when navigating an imaging system to capture a desired patient image. Such intermittent removal of AR headset for interacting with a patient or an imaging system interface can raise issues with sterility and great undesirable interruptions between surgical procedure stages, such as while the personnel performs operations to recalibrate the AR headset. 
     Various embodiments use custom mapped controls that are performed through the AR headset which are configured to navigate user interfaces of imaging systems and other medical devices during a surgical procedure. For example, a wearer can interact with the AR headset using hand gesture commands and/or voice commands to control positioning of an imaging system, to plan an imaging shot on the imaging system, to initiate the imaging shot, and/or to use an obtained imaging shot to plan trajectories for one or more medical implants and associated surgical tools. 
     Various previously known medical devices, such as various surgical robots and imaging systems are known to provide only a physical user interface for manipulation during planning of a surgical procedure and during implementation performance of the surgical procedure. If the surgeon were wearing an AR headset, the surgeon may feel the need to remove the AR headset in order to travel to and freely control the physical user interface of various medical devices in the operating room. 
     In accordance with various embodiments herein, the AR headset enables the wearer to enter information and control operation of medical devices which are operatively connected (wired/wireless communication connections) to the AR headset, through hand gesture commands, voice commands, and/or other commands that can be sensed by and/or input to the AR headset. The AR headset thereby enables the wearer to maintain focus on the surgical procedure as it is occurring in front of the wearer and maintain sterility and control of the surgical workflow. 
     In one embodiment, the AR headset is operatively connected to an imaging system and configured to provide information and/or commands to the imaging system based on identification of hand gesture commands, voice commands, and/or other commands that are sensed by and/or input to the AR headset. Navigation control of the imaging system can be mapped to the virtual space of the AR headset. The AR headset can be used to control movement of the imaging system into a desired position relative to the patient, adjust an imaging shot position, select scan settings for the imaging shot (e.g., patient information, type of scan, etc., and initiate the imaging shot spin through the use of virtual controls that can include hand gestures performed relative to virtual menus displayed on the display screen  1450  and/or voice commands. By using virtual controls, physical contact between the wearer&#39;s hands and the imaging system is avoided. For improved safety, a dead-man switch, e.g. a fail-safe switch which prevents movement of the imaging system when released, can be included in the form of a foot pedal for use by the AR headset wearer. 
     The AR headset can be configured to provide an unencumbered view of the typical field of view in front of the wearer, which can be clear until menus items are initiated responsive to an identified and gesture command, voice command, and/or another command that is sensed by and/or input to the AR headset. When a C-arm imaging device captures multiple images for a surgical procedure, the images can be stored in the image database  950 . Perspectives and other views for the procedure unique to each imaging system provide the wearer multiple ways to ensure accuracy of the planned tool trajectory, as well as selection of the correct tool and implant for use during the surgical procedure. 
     In some other embodiments, the AR headset is operatively connected to control transfer of surgical plan workflows and/or other information, e.g., images, from the surgical planning computer  910  to the surgical robot  4 , between two surgical robots  4 , and/or between the surgical robot  4  and other medical devices. 
     In one embodiment, they are headset is operatively connected to control cross-platform integration between one or more imaging systems, e.g., the C-arm imaging device  104  and/or the O-arm imaging device  106 , and the surgical planning computer  910 . A wearer can manipulate control menus mapped in the virtual space of the AR headset to allow separate control of the imaging system and the surgical planning computer  910 . The wearer may navigate through control menus provided by the AR headset to plan and conduct imaging spins by the imaging system, and then rapidly conduct trajectory planning and tool selection through the surgical planning computer  910  using the obtained images. 
     In a further embodiment, as the sight line of the AR headset wearer becomes directed towards a surgical robot  4 , a graphical indicator can be displayed as an overlay that indicates that the wearer can now interface through the AR headset to control various operational functions of the surgical robot  4 . 
     In another further embodiment, as the sight line of the AR headset wearer becomes directed towards a rod bender device, e.g., used for spinal alignment procedures, a graphical indicator can be displayed as an overlay that indicates that the wearer can now interface through the AR headset to control various operational functions of the rod bender, such as to shape rod implants based on present data from the surgical planning computer  910  that is generated through planning of screw placement relative to one or more of the obtained medical image. 
     These and other related cross-platform operations that integrate an AR headset with various medical devices can reduce unnecessary downtime between stages of a surgical planning and execution procedure. By allowing the areas processes and workflows to transmit information between the various devices, more than one of the devices can be simultaneously working on the same workflow. These operations can avoid typical pauses that occur during a surgical procedure in the operating room while surgeons sequentially move through stages to obtain spinal images, plan screw placement within a spine using the spinal images, and shape a rod for connection to the spine. 
     An example workflow according to present embodiments can include, using the AR headset for navigation the wearer guides the C-arm imaging device  104  into position in order to take an imaging scan of the patient. Once in position, the wearer can use the AR headset display screen  1452  to find operational preferences for the imaging spin and to perform the imaging spin. The imaging spin generates a static image upon which the wearer uses to plan screw trajectories through the surgical planning computer  910 . Once the screw trajectories are planned, the wearer transfers the surgical plan to the surgical robot  4  to obtain navigated assistance during screw placement into the spine. Simultaneously, upon completion of trajectory planning, the wearer can send the completed trajectory plan to the rod bender device which begins bending of the spinal correction rod. While the rod bender device is bending the spinal correction rod using the completed trajectory plan, the wearer can use the AR headset to aid in screw placement through operation of the surgical robot  4 . Once the screws are successfully in place in the patient&#39;s spine, the wearer can use a virtual model of the spinal correction rod generated from the cross-platform integration between the surgical robot  4  and rod bender device to ensure accuracy of the rod fitment to the screw trajectory before rod placement is performed. 
     Thus, in some further embodiments, the AR headset controller is configured to associate a set of defined hand gestures and/or a set of defined voice commands with a set of control commands for at least one external medical device, and identify occurrence of one of the defined hand gestures in a camera video stream and/or occurrence of one of the defined voice commands in an audio stream. The AR headset controller is configured to select a control command from among the set of control commands responsive to the identified occurrence of the one of the defined hand gestures and/or defined voice commands, and to communicate the selected control command to the external medical device. 
     In one embodiment, the set of control commands for the external medical device includes a command that controls at least one of movement of an imaging system, adjustment a region that is to be captured by the imaging system in an image, and initiate capture of the image by the imaging system. 
     In one embodiment, the set of control commands for the external medical device includes a command that controls at least one of transfer of a trajectory plan for a spinal correction rod to a rod bender device, initiating bending of the spinal correction rod by the rod bender device, and transfer of operational status information from the rod bender device to the AR headset for display. 
     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.