Patent Publication Number: US-2020297451-A1

Title: System for robotic trajectory guidance for navigated biopsy needle, and related methods and devices

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/361,863, filed Mar. 22, 2019, the entire contents of all of which are hereby incorporated by reference. 
    
    
     FIELD 
     The present disclosure relates to medical devices and systems, and more particularly, systems for robotic trajectory guidance for a navigated biopsy needle, and related methods and devices. 
     BACKGROUND 
     Position recognition systems for robot assisted surgeries are used to determine the position of and track a particular object in 3-dimensions (3D). In robot assisted surgeries, for example, certain objects, such as surgical instruments, need to be tracked with a high degree of precision as the instrument is being positioned and moved by a robot or by a physician, for example. 
     Position recognition systems may use passive and/or active sensors or markers for registering and tracking the positions of the objects. Using these sensors, the system may geometrically resolve the 3-dimensional position of the sensors based on information from or with respect to one or more cameras, signals, or sensors, etc. These surgical systems can therefore utilize position feedback to precisely guide movement of robotic arms and tools relative to a patients&#39; surgical site. Thus, there is a need for a system that efficiently and accurately provide neuronavigation registration and robotic trajectory guidance in a surgical environment. 
     One surgical instrument used in traditional neurological procedures is a biopsy needle. A biopsy involves extraction of tissue to discover the presence, cause, and/or extent of a disease. The trajectory and position of the biopsy needle in traditional procedures is not tracked in a 3D space using position recognition systems. Thus, there is a need for navigated biopsy needle and procedure that allows for the biopsy to be tracked using a surgical navigation system. There is also a need for a navigated biopsy needle compatible with a navigated robotic end effector and overcoming the problem of providing real time feedback regarding insertion depth and trajectory of the biopsy while it is inserted into a patient. 
     SUMMARY 
     To meet this and other needs, devices, systems, and methods for navigating a surgical implant are provided. 
     According to an exemplary embodiment, a surgical robot system for inserting biopsy needle into a target area of a patient includes a robot base comprising a computer, a robot arm coupled to the robot base, an end effector configured to be coupled to the robot arm, and a biopsy needle, containing tracking markers visible to a camera, configured to be coupled to the end effector. 
     According to another exemplary embodiment, a method of using a surgical robot for inserting a biopsy needle into a patient includes identifying the target area for insertion of the biopsy needle, planning a trajectory to the target area using a computer of the surgical robot, drilling into a skull of the patient using a surgical drill, penetrating dura of the skull with the surgical drill, setting an insertion depth of the biopsy needle, inserting the biopsy needle into an end effector of the surgical robot to the target area, aspirating a sample of tissue using the biopsy needle, removing the biopsy needle from the patient and the end effector, and monitoring the position of the biopsy needle using tracking markers disposed on the biopsy needle configured to being viewable by a camera of the surgical robot system. 
    
    
     
       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. 1A  is an overhead view of an arrangement for locations of a robotic system, patient, surgeon, and other medical personnel during a surgical procedure, according to some embodiments; 
         FIG. 1B  is an overhead view of an alternate arrangement for locations of a robotic system, patient, surgeon, and other medical personnel during a cranial surgical procedure, according to some embodiments; 
         FIG. 2  illustrates a robotic system including positioning of the surgical robot and a camera relative to the patient according to some embodiments; 
         FIG. 3  is a flowchart diagram illustrating computer-implemented operations for determining a position and orientation of an anatomical feature of a patient with respect to a robot arm of a surgical robot, according to some embodiments; 
         FIG. 4  is a diagram illustrating processing of data for determining a position and orientation of an anatomical feature of a patient with respect to a robot arm of a surgical robot, according to some embodiments; 
         FIGS. 5A-5C  illustrate a system for registering an anatomical feature of a patient using a computerized tomography (CT) localizer, a frame reference array (FRA), and a dynamic reference base (DRB), according to some embodiments; 
         FIGS. 6A and 6B  illustrate a system for registering an anatomical feature of a patient using fluoroscopy (fluoro) imaging, according to some embodiments; 
         FIG. 7  illustrates a system for registering an anatomical feature of a patient using an intraoperative CT fixture (ICT) and a DRB, according to some embodiments; 
         FIGS. 8A and 8B  illustrate systems for registering an anatomical feature of a patient using a DRB and an X-ray cone beam imaging device, according to some embodiments; 
         FIG. 9  illustrates a system for registering an anatomical feature of a patient using a navigated probe and fiducials for point-to-point mapping of the anatomical feature, according to some embodiments; 
         FIG. 10  illustrates a two-dimensional visualization of an adjustment range for a centerpoint-arc mechanism, according to some embodiments; and 
         FIG. 11  illustrates a two-dimensional visualization of virtual point rotation mechanism, according to some embodiments. 
         FIG. 12  illustrates an exemplary workflow for using a navigated biopsy needle with a surgical robot, according to some embodiments. 
         FIG. 13  illustrates an exemplary navigated biopsy needle, according to some embodiments. 
         FIG. 14  illustrates an exemplary navigated biopsy needle, according to some embodiments. 
         FIG. 15  illustrates an exemplary navigated biopsy needle, according to some embodiments. 
         FIG. 16  illustrates an exemplary navigated biopsy needle with a ruler, according to some embodiments. 
         FIG. 17  illustrates an exemplary navigated biopsy needle in an exemplary end effector, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the description herein or illustrated in the drawings. The teachings of the present disclosure may be used and practiced in other embodiments and practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     The following discussion is presented to enable a person skilled in the art to make and use embodiments of the present disclosure. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the principles herein can be applied to other embodiments and applications without departing from embodiments of the present disclosure. Thus, the embodiments are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the embodiments. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of the embodiments. 
     According to some other embodiments, systems for neuronavigation registration and robotic trajectory guidance, and related methods and devices are disclosed. In some embodiments, a first image having an anatomical feature of a patient, a registration fixture that is fixed with respect to the anatomical feature of the patient, and a first plurality of fiducial markers that are fixed with respect to the registration fixture is analyzed, and a position is determined for each fiducial marker of the first plurality of fiducial markers. Next, based on the determined positions of the first plurality of fiducial markers, a position and orientation of the registration fixture with respect to the anatomical feature is determined. A data frame comprising a second plurality of tracking markers that are fixed with respect to the registration fixture is also analyzed, and a position is determined for each tracking marker of the second plurality of tracking markers. Based on the determined positions of the second plurality of tracking markers, a position and orientation of the registration fixture with respect to a robot arm of a surgical robot is determined. Based on the determined position and orientation of the registration fixture with respect to the anatomical feature and the determined position and orientation of the registration fixture with respect to the robot arm, a position and orientation of the anatomical feature with respect to the robot arm is determined, which allows the robot arm to be controlled based on the determined position and orientation of the anatomical feature with respect to the robot arm. 
     Advantages of this and other embodiments include the ability to combine neuronavigation and robotic trajectory alignment into one system, with support for a wide variety of different registration hardware and methods. For example, as will be described in detail below, embodiments may support both computerized tomography (CT) and fluoroscopy (fluoro) registration techniques, and may utilize frame-based and/or frameless surgical arrangements. Moreover, in many embodiments, if an initial (e.g. preoperative) registration is compromised due to movement of a registration fixture, registration of the registration fixture (and of the anatomical feature by extension) can be re-established intraoperatively without suspending surgery and re-capturing preoperative images. 
     Referring now to the drawings,  FIG. 1A  illustrates a surgical robot system  100  in accordance with an embodiment. Surgical robot system  100  may include, for example, a surgical robot  102 , one or more robot arms  104 , a base  106 , a display  110 , an end-effector  112 , for example, including a guide tube  114 , and one or more tracking markers  118 . The robot arm  104  may be movable along and/or about an axis relative to the base  106 , responsive to input from a user, commands received from a processing device, or other methods. The surgical robot system  100  may include a patient tracking device  116  also including one or more tracking markers  118 , which is adapted to be secured directly to the patient  210  (e.g., to a bone of the patient  210 ). As will be discussed in greater detail below, the tracking markers  118  may be secured to or may be part of a stereotactic frame that is fixed with respect to an anatomical feature of the patient  210 . The stereotactic frame may also be secured to a fixture to prevent movement of the patient  210  during surgery. 
     According to an alternative embodiment,  FIG. 1B  is an overhead view of an alternate arrangement for locations of a robotic system  100 , patient  210 , surgeon  120 , and other medical personnel during a cranial surgical procedure. During a cranial procedure, for example, the robot  102  may be positioned behind the head  128  of the patient  210 . The robot arm  104  of the robot  102  has an end-effector  112  that may hold a surgical instrument  108  during the procedure. In this example, a stereotactic frame  134  is fixed with respect to the patient&#39;s head  128 , and the patient  210  and/or stereotactic frame  134  may also be secured to a patient base  211  to prevent movement of the patient&#39;s head  128  with respect to the patient base  211 . In addition, the patient  210 , the stereotactic frame  134  and/or or the patient base  211  may be secured to the robot base  106 , such as via an auxiliary arm  107 , to prevent relative movement of the patient  210  with respect to components of the robot  102  during surgery. Different devices may be positioned with respect to the patient&#39;s head  128  and/or patient base  211  as desired to facilitate the procedure, such as an intra-operative CT device  130 , an anesthesiology station  132 , a scrub station  136 , a neuro-modulation station  138 , and/or one or more remote pendants  140  for controlling the robot  102  and/or other devices or systems during the procedure. 
     The surgical robot system  100  in the examples of  FIGS. 1A and/or 1B  may also use a sensor, such as a camera  200 , for example, positioned on a camera stand  202 . The camera stand  202  can have any suitable configuration to move, orient, and support the camera  200  in a desired position. The camera  200  may include any suitable camera or cameras, such as one or more cameras (e.g., bifocal or stereophotogrammetric cameras), able to identify, for example, active or passive tracking markers  118  (shown as part of patient tracking device  116  in  FIG. 2 ) in a given measurement volume viewable from the perspective of the camera  200 . In this example, the camera  200  may scan the given measurement volume and detect the light that comes from the tracking markers  118  in order to identify and determine the position of the tracking markers  118  in three-dimensions. For example, active tracking markers  118  may include infrared-emitting markers that are activated by an electrical signal (e.g., infrared light emitting diodes (LEDs)), and/or passive tracking markers  118  may include retro-reflective markers that reflect infrared or other light (e.g., they reflect incoming IR radiation into the direction of the incoming light), for example, emitted by illuminators on the camera  200  or other suitable sensor or other device. 
     In many surgical procedures, one or more targets of surgical interest, such as targets within the brain for example, are localized to an external reference frame. For example, stereotactic neurosurgery may use an externally mounted stereotactic frame that facilitates patient localization and implant insertion via a frame mounted arc. Neuronavigation is used to register, e.g., map, targets within the brain based on pre-operative or intraoperative imaging. Using this pre-operative or intraoperative imaging, links and associations can be made between the imaging and the actual anatomical structures in a surgical environment, and these links and associations can be utilized by robotic trajectory systems during surgery. 
     According to some embodiments, various software and hardware elements may be combined to create a system that can be used to plan, register, place and verify the location of an instrument or implant in the brain. These systems may integrate a surgical robot, such as the surgical robot  102  of  FIGS. 1A and/or 1B , and may employ a surgical navigation system and planning software to program and control the surgical robot. In addition or alternatively, the surgical robot  102  may be remotely controlled, such as by nonsterile personnel. 
     The robot  102  may be positioned near or next to patient  210 , and it will be appreciated that the robot  102  can be positioned at any suitable location near the patient  210  depending on the area of the patient  210  undergoing the operation. The camera  200  may be separated from the surgical robot system  100  and positioned near or next to patient  210  as well, in any suitable position that allows the camera  200  to have a direct visual line of sight to the surgical field  208 . In the configuration shown, the surgeon  120  may be positioned across from the robot  102 , but is still able to manipulate the end-effector  112  and the display  110 . A surgical assistant  126  may be positioned across from the surgeon  120  again with access to both the end-effector  112  and the display  110 . If desired, the locations of the surgeon  120  and the assistant  126  may be reversed. The traditional areas for the anesthesiologist  122  and the nurse or scrub tech  124  may remain unimpeded by the locations of the robot  102  and camera  200 . 
     With respect to the other components of the robot  102 , the display  110  can be attached to the surgical robot  102  and in other embodiments, the display  110  can be detached from surgical robot  102 , either within a surgical room with the surgical robot  102 , or in a remote location. The end-effector  112  may be coupled to the robot arm  104  and controlled by at least one motor. In some embodiments, end-effector  112  can comprise a guide tube  114 , which is able to receive and orient a surgical instrument  108  used to perform surgery on the patient  210 . As used herein, the term “end-effector” is used interchangeably with the terms “end-effectuator” and “effectuator element.” Although generally shown with a guide tube  114 , it will be appreciated that the end-effector  112  may be replaced with any suitable instrumentation suitable for use in surgery. In some embodiments, end-effector  112  can comprise any known structure for effecting the movement of the surgical instrument  108  in a desired manner. 
     The surgical robot  102  is able to control the translation and orientation of the end-effector  112 . The robot  102  is able to move end-effector  112  along x-, y-, and z-axes, for example. The end-effector  112  can be configured for selective rotation about one or more of the x-, y-, and z-axis such that one or more of the Euler Angles (e.g., roll, pitch, and/or yaw) associated with end-effector  112  can be selectively controlled. In some embodiments, selective control of the translation and orientation of end-effector  112  can permit performance of medical procedures with significantly improved accuracy compared to conventional robots that use, for example, a six degree of freedom robot arm comprising only rotational axes. For example, the surgical robot system  100  may be used to operate on patient  210 , and robot arm  104  can be positioned above the body of patient  210 , with end-effector  112  selectively angled relative to the z-axis toward the body of patient  210 . 
     In some embodiments, the position of the surgical instrument  108  can be dynamically updated so that surgical robot  102  can be aware of the location of the surgical instrument  108  at all times during the procedure. Consequently, in some embodiments, surgical robot  102  can move the surgical instrument  108  to the desired position quickly without any further assistance from a physician (unless the physician so desires). In some further embodiments, surgical robot  102  can be configured to correct the path of the surgical instrument  108  if the surgical instrument  108  strays from the selected, preplanned trajectory. In some embodiments, surgical robot  102  can be configured to permit stoppage, modification, and/or manual control of the movement of end-effector  112  and/or the surgical instrument  108 . Thus, in use, in some embodiments, a physician or other user can operate the system  100 , and has the option to stop, modify, or manually control the autonomous movement of end-effector  112  and/or the surgical instrument  108 . Further details of surgical robot system  100  including the control and movement of a surgical instrument  108  by surgical robot  102  can be found in co-pending U.S. Patent Publication No. 2013/0345718, which is incorporated herein by reference in its entirety. 
     As will be described in greater detail below, the surgical robot system  100  can comprise one or more tracking markers configured to track the movement of robot arm  104 , end-effector  112 , patient  210 , and/or the surgical instrument  108  in three dimensions. In some embodiments, a plurality of tracking markers can be mounted (or otherwise secured) thereon to an outer surface of the robot  102 , such as, for example and without limitation, on base  106  of robot  102 , on robot arm  104 , and/or on the end-effector  112 . In some embodiments, such as the embodiment of  FIG. 3  below, for example, one or more tracking markers can be mounted or otherwise secured to the end-effector  112 . One or more tracking markers can further be mounted (or otherwise secured) to the patient  210 . In some embodiments, the plurality of tracking markers can be positioned on the patient  210  spaced apart from the surgical field  208  to reduce the likelihood of being obscured by the surgeon, surgical tools, or other parts of the robot  102 . Further, one or more tracking markers can be further mounted (or otherwise secured) to the surgical instruments  108  (e.g., a screw driver, dilator, implant inserter, or the like). Thus, the tracking markers enable each of the marked objects (e.g., the end-effector  112 , the patient  210 , and the surgical instruments  108 ) to be tracked by the surgical robot system  100 . In some embodiments, system  100  can use tracking information collected from each of the marked objects to calculate the orientation and location, for example, of the end-effector  112 , the surgical instrument  108  (e.g., positioned in the tube  114  of the end-effector  112 ), and the relative position of the patient  210 . Further details of surgical robot system  100  including the control, movement and tracking of surgical robot  102  and of a surgical instrument  108  can be found in U.S. Patent Publication No. 2016/0242849, which is incorporated herein by reference in its entirety. 
     In some embodiments, pre-operative imaging may be used to identify the anatomy to be targeted in the procedure. If desired by the surgeon the planning package will allow for the definition of a reformatted coordinate system. This reformatted coordinate system will have coordinate axes anchored to specific anatomical landmarks, such as the anterior commissure (AC) and posterior commissure (PC) for neurosurgery procedures. In some embodiments, multiple pre-operative exam images (e.g., CT or magnetic resonance (MR) images) may be co-registered such that it is possible to transform coordinates of any given point on the anatomy to the corresponding point on all other pre-operative exam images. 
     As used herein, registration is the process of determining the coordinate transformations from one coordinate system to another. For example, in the co-registration of preoperative images, co-registering a CT scan to an MR scan means that it is possible to transform the coordinates of an anatomical point from the CT scan to the corresponding anatomical location in the MR scan. It may also be advantageous to register at least one exam image coordinate system to the coordinate system of a common registration fixture, such as a dynamic reference base (DRB), which may allow the camera  200  to keep track of the position of the patient in the camera space in real-time so that any intraoperative movement of an anatomical point on the patient in the room can be detected by the robot system  100  and accounted for by compensatory movement of the surgical robot  102 . 
       FIG. 3  is a flowchart diagram illustrating computer-implemented operations  300  for determining a position and orientation of an anatomical feature of a patient with respect to a robot arm of a surgical robot, according to some embodiments. The operations  300  may include receiving a first image volume, such as a CT scan, from a preoperative image capture device at a first time (Block  302 ). The first image volume includes an anatomical feature of a patient and at least a portion of a registration fixture that is fixed with respect to the anatomical feature of the patient. The registration fixture includes a first plurality of fiducial markers that are fixed with respect to the registration fixture. The operations  300  further include determining, for each fiducial marker of the first plurality of fiducial markers, a position of the fiducial marker relative to the first image volume (Block  304 ). The operations  300  further include, determining, based on the determined positions of the first plurality of fiducial markers, positions of an array of tracking markers on the registration fixture (fiducial registration array or FRA) with respect to the anatomical feature (Block  306 ). 
     The operations  300  may further include receiving a tracking data frame from an intraoperative tracking device comprising a plurality of tracking cameras at a second time that is later than the first time (Block  308 ). The tracking frame includes positions of a plurality of tracking markers that are fixed with respect to the registration fixture (FRA) and a plurality of tracking markers that are fixed with respect to the robot. The operations  300  further include determining, for based on the positions of tracking markers of the registration fixture, a position and orientation of the anatomical feature with respect to the tracking cameras (Block  310 ). The operations  300  further include determining, based on the determined positions of the plurality of tracking markers on the robot, a position and orientation of the robot arm of a surgical robot with respect to the tracking cameras (Block  312 ). 
     The operations  300  further include determining, based on the determined position and orientation of the anatomical feature with respect to the tracking cameras and the determined position and orientation of the robot arm with respect to the tracking cameras, a position and orientation of the anatomical feature with respect to the robot arm (Block  314 ). The operations  300  further include controlling movement of the robot arm with respect to the anatomical feature, e.g., along and/or rotationally about one or more defined axis, based on the determined position and orientation of the anatomical feature with respect to the robot arm (Block  316 ). 
       FIG. 4  is a diagram illustrating a data flow  400  for a multiple coordinate transformation system, to enable determining a position and orientation of an anatomical feature of a patient with respect to a robot arm of a surgical robot, according to some embodiments. In this example, data from a plurality of exam image spaces  402 , based on a plurality of exam images, may be transformed and combined into a common exam image space  404 . The data from the common exam image space  404  and data from a verification image space  406 , based on a verification image, may be transformed and combined into a registration image space  408 . Data from the registration image space  408  may be transformed into patient fiducial coordinates  410 , which is transformed into coordinates for a DRB  412 . A tracking camera  414  may detect movement of the DRB  412  (represented by DRB  412 ′) and may also detect a location of a probe tracker  416  to track coordinates of the DRB  412  over time. A robotic arm tracker  418  determines coordinates for the robot arm based on transformation data from a Robotics Planning System (RPS) space  420  or similar modeling system, and/or transformation data from the tracking camera  414 . 
     It should be understood that these and other features may be used and combined in different ways to achieve registration of image space, i.e., coordinates from image volume, into tracking space, i.e., coordinates for use by the surgical robot in real-time. As will be discussed in detail below, these features may include fiducial-based registration such as stereotactic frames with CT localizer, preoperative CT or MRI registered using intraoperative fluoroscopy, calibrated scanner registration where any acquired scan&#39;s coordinates are pre-calibrated relative to the tracking space, and/or surface registration using a tracked probe, for example. 
     In one example,  FIGS. 5A-5C  illustrate a system  500  for registering an anatomical feature of a patient. In this example, the stereotactic frame base  530  is fixed to an anatomical feature  528  of patient, e.g., the patient&#39;s head. As shown by  FIG. 5A , the stereotactic frame base  530  may be affixed to the patient&#39;s head  528  prior to registration using pins clamping the skull or other method. The stereotactic frame base  530  may act as both a fixation platform, for holding the patient&#39;s head  528  in a fixed position, and registration and tracking platform, for alternatingly holding the CT localizer  536  or the FRA fixture  534 . The CT localizer  536  includes a plurality of fiducial markers  532  (e.g., N-pattern radio-opaque rods or other fiducials), which are automatically detected in the image space using image processing. Due to the precise attachment mechanism of the CT localizer  536  to the base  530 , these fiducial markers  532  are in known space relative to the stereotactic frame base  530 . A 3D CT scan of the patient with CT localizer  536  attached is taken, with an image volume that includes both the patient&#39;s head  528  and the fiducial markers  532  of the CT localizer  536 . This registration image can be taken intraoperatively or preoperatively, either in the operating room or in radiology, for example. The captured 3D image dataset is stored to computer memory. 
     As shown by  FIG. 5B , after the registration image is captured, the CT localizer  536  is removed from the stereotactic frame base  530  and the frame reference array fixture  534  is attached to the stereotactic frame base  530 . The stereotactic frame base  530  remains fixed to the patient&#39;s head  528 , however, and is used to secure the patient during surgery, and serves as the attachment point of a frame reference array fixture  534 . The frame reference array fixture  534  includes a frame reference array (FRA), which is a rigid array of three or more tracked markers  539 , which may be the primary reference for optical tracking. By positioning the tracked markers  539  of the FRA in a fixed, known location and orientation relative to the stereotactic frame base  530 , the position and orientation of the patient&#39;s head  528  may be tracked in real time. Mount points on the FRA fixture  534  and stereotactic frame base  530  may be designed such that the FRA fixture  534  attaches reproducibly to the stereotactic frame base  530  with minimal (i.e., submillimetric) variability. These mount points on the stereotactic frame base  530  can be the same mount points used by the CT localizer  536 , which is removed after the scan has been taken. An auxiliary arm (such as auxiliary arm  107  of  FIG. 1B , for example) or other attachment mechanism can also be used to securely affix the patient to the robot base to ensure that the robot base is not allowed to move relative to the patient. 
     As shown by  FIG. 5C , a dynamic reference base (DRB)  540  may also be attached to the stereotactic frame base  530 . The DRB  540  in this example includes a rigid array of three or more tracked markers  542 . In this example, the DRB  540  and/or other tracked markers may be attached to the stereotactic frame base  530  and/or to directly to the patient&#39;s head  528  using auxiliary mounting arms  541 , pins, or other attachment mechanisms. Unlike the FRA fixture  534 , which mounts in only one way for unambiguous localization of the stereotactic frame base  530 , the DRB  540  in general may be attached as needed for allowing unhindered surgical and equipment access. Once the DRB  540  and FRA fixture  534  are attached, registration, which was initially related to the tracking markers  539  of the FRA, can be optionally transferred or related to the tracking markers  542  of the DRB  540 . For example, if any part of the FRA fixture  534  blocks surgical access, the surgeon may remove the FRA fixture  534  and navigate using only the DRB  540 . However, if the FRA fixture  534  is not in the way of the surgery, the surgeon could opt to navigate from the FRA markers  539 , without using a DRB  540 , or may navigate using both the FRA markers  539  and the DRB  540 . In this example, the FRA fixture  534  and/or DRB  540  uses optical markers, the tracked positions of which are in known locations relative to the stereotactic frame base  530 , similar to the CT localizer  536 , but it should be understood that many other additional and/or alternative techniques may be used. 
       FIGS. 6A and 6B  illustrate a system  600  for registering an anatomical feature of a patient using fluoroscopy (fluoro) imaging, according to some embodiments. In this embodiment, image space is registered to tracking space using multiple intraoperative fluoroscopy (fluoro) images taken using a tracked registration fixture  644 . The anatomical feature of the patient (e.g., the patient&#39;s head  628 ) is positioned and rigidly affixed in a clamping apparatus  643  in a static position for the remainder of the procedure. The clamping apparatus  643  for rigid patient fixation can be a three-pin fixation system such as a Mayfield clamp, a stereotactic frame base attached to the surgical table, or another fixation method, as desired. The clamping apparatus  643  may also function as a support structure for a patient tracking array or DRB  640  as well. The DRB may be attached to the clamping apparatus using auxiliary mounting arms  641  or other means. 
     Once the patient is positioned, the fluoro fixture  644  is attached the fluoro unit&#39;s x-ray collecting image intensifier (not shown) and secured by tightening clamping feet  632 . The fluoro fixture  644  contains fiducial markers (e.g., metal spheres laid out across two planes in this example, not shown) that are visible on 2D fluoro images captured by the fluoro image capture device and can be used to calculate the location of the x-ray source relative to the image intensifier, which is typically about 1 meter away contralateral to the patient, using a standard pinhole camera model. Detection of the metal spheres in the fluoro image captured by the fluoro image capture device also enables the software to de-warp the fluoro image (i.e., to remove pincushion and s-distortion). Additionally, the fluoro fixture  644  contains 3 or more tracking markers  646  for determining the location and orientation of the fluoro fixture  644  in tracking space. In some embodiments, software can project vectors through a CT image volume, based on a previously captured CT image, to generate synthetic images based on contrast levels in the CT image that appear similar to the actual fluoro images (i.e., digitally reconstructed radiographs (DRRs)). By iterating through theoretical positions of the fluoro beam until the DRRs match the actual fluoro shots, a match can be found between fluoro image and DRR in two or more perspectives, and based on this match, the location of the patient&#39;s head  628  relative to the x-ray source and detector is calculated. Because the tracking markers  646  on the fluoro fixture  644  track the position of the image intensifier and the position of the x-ray source relative to the image intensifier is calculated from metal fiducials on the fluoro fixture  644  projected on 2D images, the position of the x-ray source and detector in tracking space are known and the system is able to achieve image-to-tracking registration. 
     As shown by  FIGS. 6A and 6B , two or more shots are taken of the head  628  of the patient by the fluoro image capture device from two different perspectives while tracking the array markers  642  of the DRB  640 , which is fixed to the registration fixture  630  via a mounting arm  641 , and tracking markers  646  on the fluoro fixture  644 . Based on the tracking data and fluoro data, an algorithm computes the location of the head  628  or other anatomical feature relative to the tracking space for the procedure. Through image-to-tracking registration, the location of any tracked tool in the image volume space can be calculated. 
     For example, in one embodiment, a first fluoro image taken from a first fluoro perspective can be compared to a first DRR constructed from a first perspective through a CT image volume, and a second fluoro image taken from a second fluoro perspective can be compared to a second DRR constructed from a second perspective through the same CT image volume. Based on the comparisons, it may be determined that the first DRR is substantially equivalent to the first fluoro image with respect to the projected view of the anatomical feature, and that the second DRR is substantially equivalent to the second fluoro image with respect to the projected view of the anatomical feature. Equivalency confirms that the position and orientation of the x-ray path from emitter to collector on the actual fluoro machine as tracked in camera space matches the position and orientation of the x-ray path from emitter to collector as specified when generating the DRRs in CT space, and therefore registration of tracking space to CT space is achieved. 
       FIG. 7  illustrates a system  700  for registering an anatomical feature of a patient using an intraoperative CT fixture (ICT) and a DRB, according to some embodiments. As shown in  FIG. 7 , in one application, a fiducial-based image-to-tracking registration can be utilized that uses an intraoperative CT fixture (ICT)  750  having a plurality of tracking markers  751  and radio-opaque fiducial reference markers  732  to register the CT space to the tracking space. After stabilizing the anatomical feature  728  (e.g., the patient&#39;s head) using clamping apparatus  730  such as a three-pin Mayfield frame and/or stereotactic frame, the surgeon will affix the ICT  750  to the anatomical feature  728 , DRB  740 , or clamping apparatus  730 , so that it is in a static position relative to the tracking markers  742  of the DRB  740 , which may be held in place by mounting arm  741  or other rigid means. A CT scan is captured that encompasses the fiducial reference markers  732  of the ICT  750  while also capturing relevant anatomy of the anatomical feature  728 . Once the CT scan is loaded in the software, the system auto-identifies (through image processing) locations of the fiducial reference markers  732  of the ICT within the CT volume, which are in a fixed position relative to the tracking markers of the ICT  750 , providing image-to-tracking registration. This registration, which was initially based on the tracking markers  751  of the ICT  750 , is then related to or transferred to the tracking markers  742  of the DRB  740 , and the ICT  750  may then be removed. 
       FIG. 8A  illustrates a system  800  for registering an anatomical feature of a patient using a DRB and an X-ray cone beam imaging device, according to some embodiments. An intraoperative scanner  852 , such as an X-ray machine or other scanning device, may have a tracking array  854  with tracking markers  855 , mounted thereon for registration. Based on the fixed, known position of the tracking array  854  on the scanning device, the system may be calibrated to directly map (register) the tracking space to the image space of any scan acquired by the system. Once registration is achieved, the registration, which is initially based on the tracking markers  855  (e.g. gantry markers) of the scanner&#39;s array  854 , is related or transferred to the tracking markers  842  of a DRB  840 , which may be fixed to a clamping fixture  830  holding the patient&#39;s head  828  by a mounting arm  841  or other rigid means. After transferring registration, the markers on the scanner are no longer used and can be removed, deactivated or covered if desired. Registering the tracking space to any image acquired by a scanner in this way may avoid the need for fiducials or other reference markers in the image space in some embodiments. 
       FIG. 8B  illustrates an alternative system  800 ′ that uses a portable intraoperative scanner, referred to herein as a C-arm scanner  853 . In this example, the C-arm scanner  853  includes a c-shaped arm  856  coupled to a movable base  858  to allow the C-arm scanner  853  to be moved into place and removed as needed, without interfering with other aspects of the surgery. The arm  856  is positioned around the patient&#39;s head  828  intraoperatively, and the arm  856  is rotated and/or translated with respect to the patient&#39;s head  828  to capture the X-ray or other type of scan that to achieve registration, at which point the C-arm scanner  853  may be removed from the patient. 
     Another registration method for an anatomical feature of a patient, e.g., a patient&#39;s head, may be to use a surface contour map of the anatomical feature, according to some embodiments. A surface contour map may be constructed using a navigated or tracked probe, or other measuring or sensing device, such as a laser pointer, 3D camera, etc. For example, a surgeon may drag or sequentially touch points on the surface of the head with the navigated probe to capture the surface across unique protrusions, such as zygomatic bones, superciliary arches, bridge of nose, eyebrows, etc. The system then compares the resulting surface contours to contours detected from the CT and/or MR images, seeking the location and orientation of contour that provides the closest match. To account for movement of the patient and to ensure that all contour points are taken relative to the same anatomical feature, each contour point is related to tracking markers on a DRB on the patient at the time it is recorded. Since the location of the contour map is known in tracking space from the tracked probe and tracked DRB, tracking-to-image registration is obtained once the corresponding contour is found in image space. 
       FIG. 9  illustrates a system  900  for registering an anatomical feature of a patient using a navigated or tracked probe and fiducials for point-to-point mapping of the anatomical feature  928  (e.g., a patient&#39;s head), according to some embodiments. Software would instruct the user to point with a tracked probe to a series of anatomical landmark points that can be found in the CT or MR image. When the user points to the landmark indicated by software, the system captures a frame of tracking data with the tracked locations of tracking markers on the probe and on the DRB. From the tracked locations of markers on the probe, the coordinates of the tip of the probe are calculated and related to the locations of markers on the DRB. Once 3 or more points are found in both spaces, tracking-to-image registration is achieved. As an alternative to pointing to natural anatomical landmarks, fiducials  954  (i.e., fiducial markers), such as sticker fiducials or metal fiducials, may be used. The surgeon will attach the fiducials  954  to the patient, which are constructed of material that is opaque on imaging, for example containing metal if used with CT or Vitamin E if used with MR. Imaging (CT or MR) will occur after placing the fiducials  954 . The surgeon or user will then manually find the coordinates of the fiducials in the image volume, or the software will find them automatically with image processing. After attaching a DRB  940  with tracking markers  942  to the patient through a mounting arm  941  connected to a clamping apparatus  930  or other rigid means, the surgeon or user may also locate the fiducials  954  in physical space relative to the DRB  940  by touching the fiducials  954  with a tracked probe while simultaneously recording tracking markers on the probe (not shown) and on the DRB  940 . Registration is achieved because the coordinates of the same points are known in the image space and the tracking space. 
     One use for the embodiments described herein is to plan trajectories and to control a robot to move into a desired trajectory, after which the surgeon will place implants such as electrodes through a guide tube held by the robot. Additional functionalities include exporting coordinates used with existing stereotactic frames, such as a Leksell frame, which uses five coordinates: X, Y, Z, Ring Angle and Arc Angle. These five coordinates are established using the target and trajectory identified in the planning stage relative to the image space and knowing the position and orientation of the ring and arc relative to the stereotactic frame base or other registration fixture. 
     As shown in  FIG. 10 , stereotactic frames allow a target location  1058  of an anatomical feature  1028  (e.g., a patient&#39;s head) to be treated as the center of a sphere and the trajectory can pivot about the target location  1058 . The trajectory to the target location  1058  is adjusted by the ring and arc angles of the stereotactic frame (e.g., a Leksell frame). These coordinates may be set manually, and the stereotactic frame may be used as a backup or as a redundant system in case the robot fails or cannot be tracked or registered successfully. The linear x,y,z offsets to the center point (i.e., target location  1058 ) are adjusted via the mechanisms of the frame. A cone  1060  is centered around the target location  1058 , and shows the adjustment zone that can be achieved by modifying the ring and arc angles of the Leksell or other type of frame. This figure illustrates that a stereotactic frame with ring and arc adjustments is well suited for reaching a fixed target location from a range of angles while changing the entry point into the skull. 
       FIG. 11  illustrates a two-dimensional visualization of virtual point rotation mechanism, according to some embodiments. In this embodiment, the robotic arm is able to create a different type of point-rotation functionality that enables a new movement mode that is not easily achievable with a 5-axis mechanical frame, but that may be achieved using the embodiments described herein. Through coordinated control of the robot&#39;s axes using the registration techniques described herein, this mode allows the user to pivot the robot&#39;s guide tube about any fixed point in space. For example, the robot may pivot about the entry point  1162  into the anatomical feature  1128  (e.g., a patient&#39;s head). This entry point pivoting is advantageous as it allows the user to make a smaller burr hole without limiting their ability to adjust the target location  1164  intraoperatively. The cone  1160  represents the range of trajectories that may be reachable through a single entry hole. Additionally, entry point pivoting is advantageous as it allows the user to reach two different target locations  1164  and  1166  through the same small entry burr hole. Alternately, the robot may pivot about a target point (e.g., location  1058  shown in  FIG. 10 ) within the skull to reach the target location from different angles or trajectories, as illustrated in  FIG. 10 . Such interior pivoting robotically has the same advantages as a stereotactic frame as it allows the user to approach the same target location  1058  from multiple approaches, such as when irradiating a tumor or when adjusting a path so that critical structures such as blood vessels or nerves will not be crossed when reaching targets beyond them. Unlike a stereotactic frame, which relies on fixed ring and arc articulations to keep a target/pivot point fixed, the robot adjusts the pivot point through controlled activation of axes and the robot can therefore dynamically adjust its pivot point and switch as needed between the modes illustrated in  FIGS. 10 and 11 . 
     Following the insertion of implants or instrumentation using the robot or ring and arc fixture, these and other embodiments may allow for implant locations to be verified using intraoperative imaging. Placement accuracy of the instrument or implant relative to the planned trajectory can be qualitatively and/or quantitatively shown to the user. One option for comparing planned to placed position is to merge a postoperative verification CT image to any of the preoperative images. Once pre- and post-operative images are merged and plan is shown overlaid, the shadow of the implant on postop CT can be compared to the plan to assess accuracy of placement. Detection of the shadow artifact on post-op CT can be performed automatically through image processing and the offset displayed numerically in terms of millimeters offset at the tip and entry and angular offset along the path. This option does not require any fiducials to be present in the verification image since image-to-image registration is performed based on bony anatomical contours. 
     A second option for comparing planned position to the final placement would utilize intraoperative fluoro with or without an attached fluoro fixture. Two out-of-plane fluoro images will be taken and these fluoro images will be matched to DRRs generated from pre-operative CT or MR as described above for registration. Unlike some of the registration methods described above, however, it may be less important for the fluoro images to be tracked because the key information is where the electrode is located relative to the anatomy in the fluoro image. The linear or slightly curved shadow of the electrode would be found on a fluoro image, and once the DRR corresponding to that fluoro shot is found, this shadow can be replicated in the CT image volume as a plane or sheet that is oriented in and out of the ray direction of the fluoro image and DRR. That is, the system may not know how deep in or out of the fluoro image plane the electrode lies on a given shot, but can calculate the plane or sheet of possible locations and represent this plane or sheet on the 3D volume. In a second fluoro view, a different plane or sheet can be determined and overlaid on the 3D image. Where these two planes or sheets intersect on the 3D image is the detected path of the electrode. The system can represent this detected path as a graphic on the 3D image volume and allow the user to reslice the image volume to display this path and the planned path from whatever perspective is desired, also allowing automatic or manual calculation of the deviation from planned to placed position of the electrode. Tracking the fluoro fixture is unnecessary but may be done to help de-warp the fluoro images and calculate the location of the x-ray emitter to improve accuracy of DRR calculation, the rate of convergence when iterating to find matching DRR and fluoro shots, and placement of sheets/planes representing the electrode on the 3D scan. 
     In this and other examples, it is desirable to maintain navigation integrity, i.e., to ensure that the registration and tracking remain accurate throughout the procedure. Two primary methods to establish and maintain navigation integrity include: tracking the position of a surveillance marker relative to the markers on the DRB, and checking landmarks within the images. In the first method, should this position change due to, for example, the DRB being bumped, then the system may alert the user of a possible loss of navigation integrity. In the second method, if a landmark check shows that the anatomy represented in the displayed slices on screen does not match the anatomy at which the tip of the probe points, then the surgeon will also become aware that there is a loss of navigation integrity. In either method, if using the registration method of CT localizer and frame reference array (FRA), the surgeon has the option to re-attach the FRA, which mounts in only one possible way to the frame base, and to restore tracking-to-image registration based on the FRA tracking markers and the stored fiducials from the CT localizer  536 . This registration can then be transferred or related to tracking markers on a repositioned DRB. Once registration is transferred the FRA can be removed if desired. 
     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 belong. 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 unless 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. 
     Turning to  FIGS. 12-17 , exemplary embodiments of the present disclosure may include systems and methods for providing and using a navigated biopsy needle.  FIG. 12  illustrates an exemplary method  1200  for performing a navigated biopsy using a position recognition system. At step  1202 , a target area for insertion of the biopsy needle may be identified and a trajectory to the target area may be planned using planning software. At step  1204 , the robot arm (such as robot arm  104 ) may be position along the planned trajectory a known distance from the target area. At step  1206 , a surgical drill may be inserted into the end-effector (such as end-effector  112 ) and used to drill a hole through the skull of the patient along the trajectory. At step  1208 , an insertion depth of the biopsy needle is set and at step  1210 , the biopsy needle is inserted through the end-effector, penetrates the dura, and proceeds to the desired target. At step  1212 , the user aspirates a sample of tissue using the biopsy needle. At step  1214 , the biopsy needle is removed from the skull and at step  1216 , the incision and insertion points are closed. Because of the tracking markers, a user may monitor the position of the biopsy needle after insertion using the surgical robot. 
       FIGS. 13 and 14  illustrate exemplary navigated biopsy needles consistent with the principles of the present disclosure. Biopsy needle  1300  may include two in-line tracking spheres  1302  that can be used to track the biopsy needles by a camera, such as camera  200 . A distal end  1304  may be inserted into the target area in order to receive the sample. A proximal end  1306  may be used by the user to insert and manipulate needle  1300   
     Alternatively,  FIG. 14  illustrates a biopsy needle  1400  that may be tracked via two disks  1402  which may be used for off-axis tracking. Both biopsy needles allow for tracking of the tip when used in conjunction with the end effector. Biopsy needle  1400  may allow for a slightly lower profile. 
       FIG. 15  illustrates exemplary biopsy needle  1300  with the two in-line tracking spheres  1302  with a depth stop  1502  on biopsy needle  1300 . Depth stop may be used to control the insertion depth of distal end  1304  of needle  1300  or needle  1400 . Setting the depth may occur at step  1210  as explained in method  1200 . In order to set the position of depth stop  1502 , a ruler may be used.  FIG. 16  illustrates an exemplary embodiment of a ruler  1600  consistent with principles of the present disclosure. Ruler  1600  may include markings  1602 . The biopsy needle may be placed in the ruler lining up the distal end to a desired depth to the target area. Depth stop  1502  may be adjusted to contact one end of the ruler. 
       FIG. 17  illustrates an exemplary embodiment of the present disclosure. Here, biopsy needle  1300 , or alternatively  1400 , is shown inserted into an exemplary end-effector  1700  of the robot arm. As noted previously depth stop  1502  controls the depth of insertion and tracking spheres  1302  are used to show the dynamic position of the needle. The end effector may control the location and height of the biopsy needle. 
     Although several embodiments of inventive concepts have been disclosed in the foregoing specification, it is understood that many modifications and other embodiments of inventive concepts will come to mind to which inventive concepts pertain, having the benefit of teachings presented in the foregoing description and associated drawings. It is thus understood that inventive concepts are not limited to the specific embodiments disclosed hereinabove, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. It is further envisioned that features from one embodiment may be combined or used with the features from a different embodiment(s) described herein. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described inventive concepts, nor the claims which follow. The entire disclosure of each patent and patent publication cited herein is incorporated by reference herein in its entirety, as if each such patent or publication were individually incorporated by reference herein. Various features and/or potential advantages of inventive concepts are set forth in the following claims.