Patent Description:
This document pertains generally, but not by way of limitation, to devices and methods for robot-assisted surgical procedures, such those involving the use of articulating arms that can be moved about multiple axes. More specifically, but not by way of limitation, the present application relates to fiducial markers that can be used to register anatomies with robotic surgical systems.

Imaging of anatomical features can be useful in preparing for and performing surgical procedures. In some procedures it can be desirable to register the shape of the anatomy in the obtained images with another frame of reference, such as the physical space of an operating room. The physical space of the operating room can be correlated to a frame of reference for a robotic surgical system. As such, it can be advantageous to ensure that the physical shape of the anatomy is recorded in imaging in such a manner that can be reproduced in the operating room.

In an example registration process, fiducial markers that can be recognized in imaging are preoperatively placed in the anatomy of a patient. The fiducial markers can comprise fasteners having a geometry that is recognizable in imaging. Multiple fiducial markers are placed on the anatomy and can be used by a physician or surgeon for planning the surgical procedure, such as by providing a reference location for where an incision or cut can be located and/or a trajectory of an instrument. After the preoperative imaging and planning, the patient with the implanted fiducial markers is brought into the physical space of the operating room. The anatomy of the patient can be immobilized and then the fiducial markers can be utilized to register the anatomy relative to the physical space of the operating room and any system associated with the referencing device. This registration can create an association between the location of the fiducial markers on the anatomy of the patient and the locations of the markers on the imaging, which can be tied back to a coordinate system for the robotic surgical system.

Examples of fiducial markers that can be used in registration procedures are described in <CIT>; <CIT>; and <CIT>.

<CIT> discloses methods and devices to track patient anatomy during a surgical operation. A patient reference device is attached to an anatomical feature of a patient and it includes an attachment base and an optically-trackable array detectable by an optical navigation system and having a longitudinally-extending arm to space apart the fixed geometric pattern from the anatomical feature. The arm includes a connector to be detachably secured to the attachment base. An inertial measurement unit within the attachment base enables determining, based on comparing a threshold level to a motion signal, that the attachment base has changed position, wherein the motion signal represents the change in position and its magnitude. Based on determining that the attachment base has changed position an alarm signal is generated an and an output device in the attachment base outputs an alarm in response to the alarm signal.

The present inventors have recognized, among other things, that a problem to be solved can include the inability or reduced ability of surgeons to recognize when a fiducial marker has been satisfactorily referenced by a referencing device. For example, the fiducial marker can be difficult to recognize when a referencing device touches the fiducial marker at the exact spot where it will be recognized in imaging or by a robotic surgical system. Fiducial markers can include a divot into which a tip of the referencing device is to be positioned to perform the registration of the fiducial marker. The divot is intended to ensure the tip of the referencing device is positioned in the same location each time it is referenced or registered. The divot can enhance the accuracy of the registration process. However, within the physical constraints of the anatomy the fiducial marker can be obstructed or partially obstructed by tissue. Furthermore, the present inventors have additionally recognized that it can be difficult to recognize when a robotic assisted referencing device touches the divot. For example, in a robotic surgical system, the surgeon might be located a distance from the fiducial marker and the tip of the referencing device thereby making viewing of the divot and the tip of the referencing device difficult.

The present subject matter can provide a solution to these and other problems, such as by providing a fiducial marker that can provide feedback, such as a physical or sensory indication, of when the fiducial marker has been engaged by a referencing device in a correct location for registration. In an example, a fiducial marker can include a light-emitting indicator that can be actuated when a tip of a referencing tool engages a divot of a fiducial marker. The light-emitting indicator can be configured to not activate if the tip only touches the side of the fiducial marker. As such, the light-emitting indicator can be configured to activate when the tip touches the center of the divot or fiducial marker, thereby providing a visual indicator to a surgeon at the fiducial marker. The indicator can also be communicated to the controls of a robotic surgical system, that the referencing tool has properly engaged the fiducial marker. Such fiducial markers of the present disclosure can reduce the time of performing surgical procedures, such as by reducing the time for the registration process, and can reduce errors in registering fiducial markers thereby improving the accuracy of subsequently performed surgical procedures.

<FIG> illustrates surgical system <NUM> for operation on surgical area <NUM> of patient <NUM> in accordance with at least one example of the present disclosure. Surgical area <NUM> in one example can include a joint and, in another example, can be a bone. Surgical area <NUM> can include any surgical area of patient <NUM>, including but not limited to the shoulder, head, elbow, thumb, spine, and the like. Surgical system <NUM> can also include robotic system <NUM> with one or more robotic arms, such as robotic arm <NUM>. As illustrated, robotic system <NUM> can utilize only a single robotic arm. Robotic arm <NUM> can be a <NUM> degree-of-freedom (DOF) robot arm, such as the ROSA robot from Medtech, a Zimmer Biomet Holdings, Inc. In some examples, robotic arm <NUM> is cooperatively controlled with surgeon input on the end effector or surgical instrument, such as surgical instrument <NUM>. In other examples, robotic arm <NUM> can operate autonomously. While not illustrated in <FIG>, one or more passive surgical support arms can be incorporated into surgical system <NUM> to assist in positioning and stabilizing instruments or anatomy during various procedures.

Each robotic arm <NUM> can rotate axially and radially and can receive a surgical instrument, or end effector, <NUM> at distal end <NUM>. Surgical instrument <NUM> can be any surgical instrument adapted for use by the robotic system <NUM>, including, for example, a gripping device such as a pincer grip, a burring device, a reaming device, an impactor device such as a humeral head impactor, a pointer, a probe or the like. Surgical instrument <NUM> can be positionable by robotic arm <NUM>, which can include multiple robotic joints, such as joints <NUM>, that allow surgical instrument <NUM> to be positioned at any desired location adjacent or within a given surgical area <NUM>. As discussed below, robotic arm <NUM> can be used with a probe instrument, e.g., pointer probe <NUM> (<FIG>), to register surgical area <NUM> to computing system <NUM>.

Robotic system <NUM> can also include computing system <NUM> that can operate robotic arm <NUM> and surgical instrument <NUM>. Computing system <NUM> can include at least memory, a processing unit, and user input devices, as will be described herein. Computing system <NUM> can also include human interface device <NUM> for providing images for a surgeon to be used during surgery. Computing system <NUM> is illustrated as a separate standalone system, but in some examples computing system <NUM> can be integrated into robotic system <NUM>. Human interface device <NUM> can provide images, including but not limited to three-dimensional images of bones, glenoid, joints, and the like. Human interface device <NUM> can include associated input mechanisms, such as a touch screen, foot pedals, or other input devices compatible with a surgical environment.

Computing system <NUM> can receive pre-operative, intra-operative and post-operative medical images. These images can be received in any manner and the images can include, but are not limited to, computed tomography (CT) scans, magnetic resonance imaging (MRI), two-dimensional x-rays, three-dimensional x-rays, ultrasound, and the like. These images in one example can be sent via a server as files attached to an email. In another example the images can be stored on an external memory device such as a memory stick and coupled to a USB port of the robotic system to be uploaded into the processing unit. In yet other examples, the images can be accessed over a network by computing system <NUM> from a remote storage device or service.

After receiving one or more images, computing system <NUM> can generate one or more virtual models related to surgical area <NUM>. Specifically, a virtual model of the anatomy of patient <NUM> can be created by defining anatomical points within the image(s) and/or by fitting a statistical anatomical model to the image data. The virtual model, along with virtual representations of implants, can be used for calculations related to the desired height, depth, inclination angle, or version angle of an implant, stem, surgical instrument, or the like related to be utilized in surgical area <NUM>. In another procedure type, the virtual model can be utilized to determine insertion location, trajectory and depth for inserting an instrument. The virtual model can also be used to determine bone dimensions, implant dimensions, bone fragment dimensions, bone fragment arrangements, and the like. Any model generated, including three-dimensional models, can be displayed on human interface device <NUM> for reference during a surgery or used by robotic system <NUM> to determine motions, actions, and operations of robotic arm <NUM> or surgical instrument <NUM>. Known techniques for creating virtual bone models can be utilized, such as those discussed in <CIT>, titled "Deformable articulating templates" or <CIT>, titled "Method of generating a patient-specific bone shell" both by Mohamed Rashwan Mahfouz, as well as other techniques known in the art.

Computing system <NUM> can also communicate with tracking system <NUM> that can be operated by computing system <NUM> as a stand-alone unit. Surgical system <NUM> can utilize the Polaris optical tracking system from Northern Digital, Inc. of Waterloo, Ontario, Canada. Tracking system <NUM> can monitor a plurality of tracking elements, such as tracking elements <NUM>, affixed to objects of interest to track locations of multiple objects within the surgical field. Tracking system <NUM> functions to create a virtual three-dimensional coordinate system within the surgical field for tracking patient anatomy, surgical instruments, or portions of robotic system <NUM>. Tracking elements <NUM> can be tracking frames including multiple IR reflective tracking spheres, or similar optically tracked marker devices. In one example, tracking elements <NUM> can be placed on or adjacent one or more bones of patient <NUM>. In other examples, tracking elements <NUM> can be placed on robot robotic arm <NUM>, surgical instrument <NUM>, and/or an implant to accurately track positions within a virtual coordinate system associated with surgical system <NUM>. In each instance tracking elements <NUM> can provide position data, such as patient position, bone position, joint position, robotic arm position, implant position, or the like.

Robotic system <NUM> can include various additional sensors and guide devices. For example, robotic system <NUM> can include one or more force sensors, such as force sensor <NUM>. Force sensor <NUM> can provide additional force and torque data or information to computing system <NUM> of robotic system <NUM>. Force sensor <NUM> can be used to monitor impact or implantation forces during certain operations, such as insertion of an implant stem into a humeral canal. Monitoring forces can assist in preventing negative outcomes through force fitting components. In other examples, force sensor <NUM> can provide information on soft-tissue tension in the tissues surrounding a target joint. In certain examples, robotic system <NUM> can also include laser pointer <NUM> that can generate a laser beam or array that is used for alignment of implants during surgical procedures.

As discussed herein, in order to ensure that computing system <NUM> is moving robotic arm <NUM> in a known and fixed relationship, or in a real-time continuously updated relationship, to surgical area <NUM> and patient <NUM>, the space of surgical area <NUM> and patient <NUM> can be registered to computing system <NUM> via a registration process involving registering fiducial markers attached to patient <NUM> with corresponding images of the markers in patient <NUM> recorded preoperatively or just prior to a surgical procedure (such as for registration purposes during surgery) or post-procedure (such as for verification purposes at the end of surgery). For example, a plurality of fiducial markers can be attached to patient <NUM>, images of patient <NUM> with the fiducial markers can be taken or obtained and stored within a memory device of computing system <NUM>. Subsequently, patient <NUM> with the fiducial markers can be moved into, if not already there because of the imaging, surgical area <NUM> and robotic arm <NUM> can touch each of the fiducial markers. Engagement of each of the fiducial markers can be cross-referenced with, or registered to, the location of the same fiducial marker in the images. As such, the real-world, three-dimensional geometry of the anatomy attached to the fiducial markers can be correlated to the anatomy in the images and movements of instruments <NUM> attached to robotic arm <NUM> based on the images will correspondingly occur in surgical area <NUM>. Fiducial markers described herein can facilitate the registration process by providing feedback, such as visual or other sensory feedback that can be electronically generated, to a surgeon or operator of surgical system <NUM> to ensure that instrument <NUM> attached to robotic arm <NUM> adequately engages each fiducial marker.

<FIG> is a schematic view of robotic arm <NUM> of <FIG> including pointer probe <NUM> shown positioned relative to skull <NUM> having fiducial markers 204A, 204B and 204C implanted therein. Pointer probe <NUM> can include shaft <NUM>, probe extension <NUM> and probe tip <NUM>. As shown with reference to fiducial marker 204A, fiducial markers 204A - 204C can include fastener <NUM> and light-up cap <NUM>. Robotic arm <NUM> can include joint 135A that permits rotation about axis 216A, joint 135B that can permit rotation about axis 216B, joint 135C that can permit rotation about axis 216C and joint 135D that can permit rotation about axis 216D.

In order to register the anatomy and geometry of skull <NUM> to surgical system <NUM> (<FIG>), robotic arm <NUM> can be manipulated automatically by computing system <NUM>, using incremental micro-movements, for example, or a surgeon manually operating computing system <NUM> to engage probe tip <NUM> with each of fiducial markers 204A, 204B and 204C. For example, robotic arm <NUM> can be manipulated along axes 216A - 216D to engage probe tip <NUM> with the center of each fiducial marker 204A - 204C. Thus, it can require skill and dexterity to ensure probe tip <NUM> engages fiducial markers 204A - 204C.

In additional examples, robotic arm <NUM> can be separately registered to the coordinate system of surgical system <NUM>, such via use of a tracking element <NUM>. Fiducial markers 204A - 204C can additionally be separately registered to the coordinate system of surgical system <NUM> via engagement with a probe having a tracking element <NUM> attached thereto. As such, some or all of the components of surgical system <NUM> can be individually registered to the coordinate system and, if desired, movement of such components can be continuously or intermittently tracked with a tracking element <NUM>.

It can be a difficult task to ensure that probe <NUM> properly seats against each of fiducial markers 204A - 204C. For example, fiducial markers 204A -204C can be obstructed by tissue attached to skull <NUM> or the surgeon may not have the best line of sight of each of fiducial markers 204A - 204C from the vantage point of human interface device <NUM>, for example. Furthermore, even if each of fiducial markers 204A - 204C is clearly visible, it can be difficult to ensure probe tip <NUM> engages the center of fiducial markers 204A - 204C to most accurately register each point, or even if aligned with the center, advanced far enough to contact the fiducial marker without moving skull <NUM> or otherwise disturbing the patient.

In order to improve the accuracy of the registration process and ensure proper or desirable engagement between each of fiducial markers 204A - 204C and probe tip <NUM>, each of fiducial markers 204A - 204C can include a sensory feedback device, such as light-up cap <NUM>. Light-up cap <NUM> can provide a visual indicator when each of fiducial marker 204A - 204C is accurately engaged, for example, when probe tip <NUM> engages the center of light-up cap <NUM>. When probe tip <NUM> does engage the center of light-up cap <NUM>, a button or switch can be actuated to activate a light source, such as a light bulb or light-emitting-diode. The light source can be a visual indication or sign to a surgeon or another operator of system <NUM> or another observer that probe tip <NUM> has engaged one of fiducial markers 204A - 204C. In other examples, light-up cap <NUM> can provide other types of sensory signals, such as auditory signals, and can provide a communication signal to computing system <NUM> to indicate the engagement between the fiducial marker and probe tip <NUM> on a display of human interface device <NUM> (<FIG>). For example, an image of patient <NUM> including fiducial markers 204A - 204C shown in human interface device <NUM> can light up at each of fiducial markers 204A - 204C as each fiducial marker is engaged.

<FIG> is a side perspective view of fiducial marker <NUM> including fastener <NUM> and light-up cap <NUM>. <FIG> is an exploded view of fiducial marker <NUM> of <FIG> showing housing <NUM>, switch <NUM>, circuit board <NUM> and power source <NUM> of light-up cap <NUM>. <FIG> and <FIG> are discussed concurrently unless specifically referenced. Light-up cap <NUM> can comprise an example of a feedback component.

Light-up cap <NUM> can comprise housing <NUM>, switch <NUM>, circuit board <NUM> and power source <NUM>. Housing <NUM> can be made of a translucent or transparent material such that components of light-up cap <NUM> can be viewed through housing <NUM>. Housing <NUM> can comprise body <NUM>, end surface <NUM>, access port <NUM>, transition portion <NUM>, fingers 238A, 238B and 238C, and slots 240A, 240B and 240C. Fastener <NUM> can comprise head <NUM>, channel <NUM>, flange <NUM>, shaft <NUM>, shoulder <NUM> and anchor portion <NUM>. Switch <NUM> can comprise button <NUM>, body <NUM>, contacts 258A and 258B and post <NUM> (<FIG>). Circuit board <NUM> can include tab <NUM> and hook <NUM> for retaining power source <NUM>.

Housing <NUM> of light-up cap <NUM> can be configured to couple to head <NUM> of fastener <NUM> such as to position switch <NUM> and access port <NUM> into axial alignment with fastener center axis AF of fastener <NUM>. In the illustrated example of <FIG>, light-up cap <NUM> is configured to be attached to fastener <NUM> after fastener <NUM> is attached to a patient. In other examples, a light-up cap can be configured to be attached to a fastener before (or after) the fastener is attached to a patient. In such embodiments, features of the fastener used to attach the fastener to anatomy (e.g., facets <NUM>) are not covered by the light-up cap. Additionally, in such embodiments, the light-up cap can be directly integrated into the head of the fastener. In such integrated examples, electronics can be embedded in a fastener. For example, near field technology, such as conductive metal, Radio Frequency Identification (RFID) tags, magnetic material, can be embedded in the head of the fastener. For such cases, probe tip <NUM> can be configured to include an appropriate sensor, such as a magnetic sensor or a conductivity/conduction sensor (e.g., current sensor) to measure the presence of magnetic material within the fastener or the presence of near field communication coil, respectively.

<FIG> is a schematic illustration of system <NUM> for sending input from fastener 222A including embedded sensor component <NUM> for sensing by pointer probe 200A including embedded sensor <NUM>. Fastener 222A can comprise head 242A, shaft 248A and anchor portion 252A. Pointer probe 200A can include shaft 206A, probe extension 208A and probe tip 210A. Fastener 222A and pointer probe 200A can be configured similarly as fastener <NUM> and pointer probe <NUM>, respectively, as described herein with the addition of sensor component <NUM> and sensor <NUM>, respectively. System <NUM> can comprise sensor component <NUM>, sensor <NUM> and controller <NUM>. Controller <NUM> can comprise an element of computing system <NUM>. In examples, controller <NUM> can be configured to communicate wirelessly or via wired connection with sensor <NUM>.

In examples, sensor component <NUM> can comprise conductive material embedded in head 242A of fastener 222A and sensor <NUM> can comprise a current sensor. Thus, when sensor <NUM> contacts or approaches head 242A, a current can be generated and passing through sensor <NUM> and <NUM> and is registered by the controller <NUM>. The magnitude of the current can be proportional to the amount of material forming sensor component <NUM> and is inversely proportional to the distance between probe tip 210A and head 242A, or otherwise influenced by the presence of sensor component <NUM>. As such, sensor <NUM> will provide a baseline output when probe tip 210A is not in contact with fastener 222A, but will output a higher, or otherwise different, output when probe tip 210A contacts head 242A. This output signal can be registered by computing system <NUM> and can be used to provide feedback information, such as a physical or sensory indication of when a fiducial marker (e.g., fastener 222A) has been engaged in a correct location for registration by probe tip 210A.

In additional examples, sensor component <NUM> can comprise magnetic material embedded in head 242A of fastener 222A and sensor <NUM> can comprise a magnetism sensor. Thus, when sensor <NUM> contacts or approaches head 242A, a magnetic field generated by sensor component <NUM> can be emitted from fastener 222A into probe tip 210A. The magnitude of the magnetic field can be proportional to the amount of material forming sensor component <NUM> and is inversely proportional to the distance between probe tip 210A and head 242A. As such, sensor <NUM> will provide a baseline output when probe tip 210A is not in contact with fastener 222A, but will output a higher, or otherwise different, output when probe tip 210A contacts head 242A. This output signal can be registered by computing system <NUM> and can be used to provide feedback information, such as a physical or sensory indication of when a fiducial marker (e.g., fastener 222A) has been engaged in a correct location for registration by probe tip 210A.

In yet other examples, sensor component <NUM> can comprise an RFID tag or the like and sensor <NUM> can comprise a chip reader or the like.

In still other examples, sensor component <NUM> can be included in a sealed cap that can be fit onto head 242A. The cap can be configured similarly to cap <NUM>, but with switch <NUM>, circuit board <NUM> and power source <NUM> replaced by sensor component <NUM>.

Further, information output from the feedback components discussed herein, such as light-up caps, conduction material, magnetic material and RFID tags, can be combined with force and torque information. In additional examples, switches (e.g., of light-up cap <NUM>) and embedded electronics can be included with or in a single fastener for redundant information for security purposes, etc..

Returning to <FIG>, fastener <NUM> can be attached to anatomy of a patient, such as by inserting anchor portion <NUM> into bone. In an embodiment, anchor portion can include one or more threads so as to be able to be threaded into bone. Shoulder <NUM> can be positioned adjacent anchor portion <NUM> and can provide a surface area for engaging bone to stop anchor portion <NUM> from being further advanced into bone. Shoulder <NUM> can also provide an anti-tilting feature to facilitate fastener <NUM> being positioned so that center axis AF can be perpendicular to a surface of the bone to which it is attached.

Shaft <NUM> can extend from shoulder <NUM> along center axis AF. Shaft <NUM> can provide clearance for head <NUM>, such as above tissue of the patient. In examples, shaft <NUM> can be in the range of approximately <NUM> to approximately <NUM> in length. Flange <NUM> can extend from shaft <NUM> to, for example, provide a feature or surface for engaging housing <NUM>. In an example, flange <NUM> can extend radially from shaft <NUM> to provide a flat distal surface for engaging fingers 238A - 238C of housing <NUM>.

Head <NUM> can be attached to an end of shaft <NUM> proximal to flange <NUM> so as to form channel <NUM> between head <NUM> and flange <NUM>. Facets <NUM> (<FIG> and <FIG>) of head <NUM> can be located proximally of channel <NUM>. Facets <NUM> can facilitate insertion into tissue or bone and assembly with light-up cap <NUM>. For example, facets <NUM> can engage working surfaces of a tool, such as a wrench, to facilitate rotation of fastener <NUM>. In examples, head <NUM> can include four of facets <NUM> to form a square or rectilinear head, though in other examples other numbers of facets can be included to, for example, form a hex head, etc. Proximal end surface <NUM> can comprise the proximal-most portion of head <NUM> and fastener <NUM>, and can be configured to engage housing <NUM>.

In an example, the distal-most end of housing <NUM> can comprise fingers 238A - 238C. Fingers 238A - 238C can be separated by slots 240A - 240C. Fingers 238A - 238C can be spread apart to fit over head <NUM> to hold housing <NUM> in engagement with fastener <NUM>. Fingers 238A - 238C can have a thickness that is thin enough to permit flexion, but thick enough to hold housing <NUM> to fastener <NUM>. In examples, the distal-most end of housing <NUM> can comprise one or more threads configured to engage corresponding threading on an instrument or fastener. Housing <NUM> can include transition portion <NUM> that can connect fingers 238A - 238C to body <NUM>. Transition portion <NUM> can comprise a flared or conical portion that extends radially from fastener center axis AF to increase the diameter of housing <NUM> at body <NUM> greater than the diameter at fingers 238A -238C. Body <NUM> can, for example, have a larger diameter than fingers 238A - 238D in order to provide space to accommodate switch <NUM>, circuit board <NUM> and power source <NUM>. Access port <NUM> can be located in end surface <NUM> of housing <NUM> to provide access to switch <NUM>, circuit board <NUM> and power source <NUM> within housing <NUM>.

With reference to <FIG>, power source <NUM> can comprise a conventional battery including an electrochemical cell, such as an alkaline or zinc-manganese battery. Power source <NUM> can comprise other types of power-providing devices, such as a rechargeable battery or a large capacitor. Power source <NUM> can be mechanically coupled to circuit board <NUM>, such as by hook <NUM>. Hook <NUM> may also provide a terminal electrically connecting to the positive or negative side of power source <NUM>. Hook <NUM> can be shaped and configured to push power source <NUM> against tab <NUM> to retain power source <NUM> against circuit board <NUM>. Tab <NUM> may also provide a terminal electrically connecting to the positive or negative side of power source <NUM>.

Circuit board <NUM> can comprise a controller for light-up cap <NUM>. Circuit board <NUM> can include circuitry that can direct power from power source <NUM> to switch <NUM>. As is discussed with reference to <FIG> circuit board <NUM> can include various other components for operating switch <NUM>, such as logic for controlling the color of one or more light-emitting sources, such as based on the number of times switch <NUM> is actuated, and a transmitter for communicating with computing system <NUM> (<FIG>). For example, the first time switch <NUM> is activated, light-emitting source <NUM> (<FIG>) can emit a first color, the second time switch <NUM> is activated, light-emitting source <NUM> can emit a second color different from the first color, and the third time switch <NUM> is activated, light-emitting source <NUM> can emit a third color different from the first and second colors. The transmitter can include circuitry to perform wireless communications, such as low-energy Bluetooth, near-field communication (NFC), or IEEE <NUM> (Wi-Fi).

Switch <NUM> can comprise elements for selectively activating a light-emitting device included therein. Contacts 258A and 258B can extend from body <NUM> of switch <NUM> to electrically connect with circuit board <NUM>. Contacts 258A and 258B can provide power coupling and communication between switch <NUM> and circuit board <NUM>. Button <NUM> can extend from body <NUM> and can house other elements of switch <NUM>. For example, as discussed with reference to <FIG>, button <NUM> can house light-emitting devices or other sensory indicators.

<FIG> is a cross-sectional view of fiducial marker <NUM> of <FIG> showing the location of switch <NUM>, circuit board <NUM> and power source <NUM> relative to access port <NUM> in housing <NUM>. Housing <NUM> can also comprise compartment <NUM>, socket <NUM>, prong <NUM> and tabs <NUM>. Head <NUM> of fastener <NUM> can further comprise proximal end surface <NUM>, facets <NUM> and divot <NUM>. Button <NUM> can further comprise light-emitting source <NUM>, spring <NUM> and seal <NUM>.

Housing <NUM> can comprise a platform for holding button <NUM> of switch <NUM>. Button <NUM> can comprise a translucent or transparent lens through with light waves from light-emitting source <NUM> can pass. Likewise, housing <NUM> can be translucent or transparent so that light waves from light-emitting source <NUM> can pass therethrough. The light waves can be generated when button <NUM> is depressed into housing <NUM> to provide an indication that pointer probe <NUM> has accurately engaged fastener <NUM> so that computing system <NUM> (<FIG>) can record the location of fastener <NUM>.

Housing <NUM> can be slid onto head <NUM> of fastener <NUM>. Head <NUM> can be pushed into socket <NUM> by an operator of fiducial marker <NUM>, such as a surgical technician or a surgeon. Under such force, fingers 238A - 238C can deflect radially outward relative to center axis AF. to permit tabs <NUM> to contacts facets <NUM>. An operator can continue to push housing <NUM> onto head <NUM> such that tabs <NUM> slide along facets <NUM> until tabs <NUM> reach channel <NUM>. Tabs <NUM> can be sized to seat between head <NUM> and flange <NUM> to hold housing <NUM> on fastener <NUM>. In an embodiment, the lengths of fingers 238A - 238C can be such that tabs <NUM> will center on channel <NUM> when proximal end surface <NUM> of head <NUM> engages flush with the top of socket <NUM>. In such an arrangement, housing <NUM> can be axially immobilized relative to central axis AF, but can rotate circumferentially about center axis AF.

Prong <NUM> can be included on housing <NUM> to seat within divot <NUM>. Divot <NUM> can be configured and shaped to receive probe tip <NUM> of pointer probe <NUM> to perform a registration procedure without light-up cap <NUM>. Divot <NUM> can comprise a semi-spherical depression or a hex-type socket. Prong <NUM> can comprise a projection to mate with divot <NUM> to, for example, facilitate seating and axial alignment between fastener <NUM> and housing <NUM> along center axis AF. In examples, prong <NUM> can be omitted from housing <NUM>.

Power source <NUM> can be positioned in compartment <NUM>, such as at the bottom or distal-most portion of compartment <NUM>. Circuit board <NUM> can be stacked on top of power source <NUM> and coupled thereto by tab <NUM> and hook <NUM>. Switch <NUM> can be stacked on top of circuit board <NUM> and coupled thereto by contacts 258A and 258B.

Access port <NUM> can be centered on end surface <NUM> and can be centered over switch <NUM>. Configured as such, button <NUM> can protrude into access port <NUM>, while housing <NUM> is located within compartment <NUM>. The shape and location of access port <NUM> can position the center of button <NUM> on center axis AF. In embodiments, the height of compartment <NUM> can correspond to the stacked height of power source <NUM>, circuit board <NUM> and housing <NUM> including contacts 258A and 258B, tab <NUM> and hook <NUM>. Likewise, the diameter of compartment <NUM> can correspond to the diameters of power source <NUM>, circuit board <NUM> and housing <NUM>. Configured as such, power source <NUM>, circuit board <NUM> and switch <NUM> can be retained within compartment <NUM> with minimal movement, while button <NUM> is free to be axially displaced along center axis AF. Access port <NUM> can center engagement with button <NUM> from probe tip <NUM>, for example.

<FIG> is a perspective view of pointer probe <NUM> of <FIG> showing probe tip <NUM>. Pointer probe <NUM> can also comprise shaft <NUM> and extension <NUM>. Pointer probe <NUM> can comprise an instrument, such as one of surgical instruments <NUM> (<FIG>) compatible with robotic arm <NUM> and surgical system <NUM> of <FIG>. Pointer probe <NUM> can comprise an instrument of known geometry relative to robotic arm <NUM> that can be used to perform registration procedures and methods with fiducial markers 204A - 204C and fiducial marker <NUM>. Probe tip <NUM> can be configured to engage with fiducial markers 204A - 204C, fiducial marker <NUM> and other fiducial markers. Probe tip <NUM> can comprise a ball-shaped body that can seat against curved surfaces of various fiducial markers, such as divot <NUM> (<FIG>) or seat <NUM> (<FIG>). The diameter of probe tip <NUM> can be sized to fit within access port <NUM> (<FIG>) of housing <NUM>. For example, the diameter of a ball of probe tip <NUM> can be sized to slip fit within access port <NUM> such that probe tip <NUM> and extension <NUM> self-center within access port <NUM> to improve the precision of the registration process. Extension <NUM> can be tapered or necked-down to a size smaller than the diameter of a ball of probe tip <NUM> to facilitate insertion of probe tip <NUM> into access port <NUM>, and extension <NUM> can have sufficient length to ensure probe tip <NUM> can extend through access port <NUM> to reach button <NUM>, as are discussed with reference to <FIG>.

<FIG> is a perspective view of a driver <NUM> configured for use with robotic arm <NUM> of <FIG> and fastener <NUM> inserted into socket <NUM> of driver <NUM>. Driver <NUM> can comprise an instrument, such as one of surgical instruments <NUM> (<FIG>) compatible with robotic arm <NUM> and surgical system <NUM> of <FIG>, or can be used in combination with a manual driver instrument. Driver <NUM> can comprise shaft <NUM>, which can include drive input end <NUM> and socket <NUM>. Drive input end <NUM> can couple to robotic arm <NUM> and can include channel <NUM> in which retention means of robotic arm <NUM> can be received to prevent driver <NUM> from being displaced from robotic arm <NUM>. Drive input end <NUM> can also include facets <NUM> for engaging a rotational drive socket of robotic arm <NUM>. In other embodiments, driver <NUM> can be used in conjunction with a manual driver handle coupled to drive input end <NUM>. As such, robotic arm <NUM> or manually-generated power can be configured to impart rotation motion to driver <NUM> along the longitudinal length of driver <NUM> via transmission of force to facets <NUM>. Rotation of driver <NUM> can additionally cause rotation of socket <NUM> to rotate fastener <NUM>. Fastener <NUM> can include head <NUM> that can be inserted into socket <NUM>. Head <NUM> can include external facets that can mate with internal facets of socket <NUM> such that rotation of socket <NUM> can be imparted to fastener <NUM>. Fastener <NUM> can include threaded shaft <NUM>. Rotation of fastener <NUM> via driver <NUM> can cause threaded shaft <NUM> to be inserted into anatomy of a patient, such as bone. Head <NUM> of fastener <NUM> can include any number of facets, such a four like fastener <NUM>. As such, driver <NUM> can be configured to drive fastener <NUM> via engagement with facets <NUM>.

<FIG> is a side cross-sectional view fiducial marker <NUM> of <FIG> showing probe tip <NUM> of pointer probe <NUM> inserted into access port <NUM> of housing <NUM>. Extension <NUM> can be tapered or necked-down to a size smaller than the diameter of a ball of probe tip <NUM> to facilitate insertion of probe tip <NUM> into access port <NUM>. Likewise, extension <NUM> can be of sufficient length to receive substantially all of probe tip <NUM>, so that the sides of probe tip <NUM> can be tangent to walls of access port <NUM>. As mentioned, access port <NUM> can be centered over button <NUM> to center probe tip <NUM> on fiducial marker <NUM>. The depth of access port <NUM> from end surface <NUM> can be long enough to receive substantially all of the ball of probe tip <NUM> to ensure that sides of probe tip <NUM> engage the walls of access port <NUM>. The diameter of access port <NUM> can be slightly larger than the diameter of probe tip <NUM> to that probe tip <NUM> can engage the walls of access port <NUM> and center probe tip <NUM> on fastener center axis AF. The relationship, e.g., dimensions, of probe tip <NUM> relative to probe shaft <NUM> can be stored in computing system <NUM> (<FIG>). For example, extension <NUM> can extend perpendicularly from the axis of probe shaft <NUM> at a known distance, and probe tip <NUM> can be located a known distance from robotic arm <NUM> (<FIG>). As such, when probe tip <NUM> engages button <NUM>, the location of fastener <NUM> can be correlated back to a location in a coordinate system for surgical area <NUM> of surgical system <NUM> (<FIG>) based on the known geometry of robotic surgical arm <NUM> or the use of tracking elements <NUM>.

<FIG> is a perspective view of fastener <NUM> for a fiducial marker that can be used with light-up cap <NUM> of <FIG> is a perspective view of pointer probe <NUM> engaging light-up cap <NUM> configured for use with fastener <NUM> of <FIG> are discussed concurrently.

Fastener <NUM> can be similar to fastener <NUM> except rather than channel <NUM>. being located below or distal to head <NUM>, ball head <NUM> is located above or proximal to head <NUM>. Fastener <NUM> can comprise similar components as fastener <NUM>, such as anchor portion <NUM>, shoulder <NUM>, shaft <NUM> and head <NUM>, which can be analogous to anchor portion <NUM>, shoulder <NUM>, shaft <NUM> and head <NUM>, respectively. Head <NUM><NUM> can be connected directly to shaft <NUM> without the presence of flange <NUM>. Head <NUM> can include facets similar to facets <NUM> for engaging a tool to rotate and implant fastener <NUM>. Ball head <NUM> can provide a separate anchor point for connection with light-up cap <NUM>. For example, flexible fingers of housing <NUM> of light-up cap <NUM> can flex around ball head <NUM> to provide coupling. Ball head <NUM> can include seat <NUM> for receiving probe tip <NUM>. Housing <NUM> can comprise features to engage seat <NUM> to facilitate coupling and immobilization of housing <NUM> relative to fastener <NUM>. Housing <NUM> can extend completely over ball head <NUM> to engage facets of head <NUM> to prevent pivoting of light-up cap <NUM> about ball head <NUM> and rotating of light-up cap <NUM> relative to shaft <NUM>. As such, housings for the fiducial marker caps, such as housings <NUM> and <NUM>, described herein can be configured to attach to different components of surgical system <NUM>, including pointer probe <NUM> as shown in <FIG>.

<FIG> is a perspective view light-up probe cap <NUM> that can be used in conjunction with fiducial marker fastener <NUM>, or other fasteners. <FIG> is a perspective view of light-up probe cap <NUM> of <FIG> engaging head <NUM> of fiducial marker fastener <NUM>. <FIG> are discussed concurrently.

Fiducial marker fastener <NUM> can include the same or similar components as fastener <NUM> identified and discussed with reference to <FIG>. Light-up probe cap <NUM> can function similarly as light-up cap <NUM> of <FIG>, but can be configured to attach to pointer probe <NUM> rather than a fiducial marker. Light-up probe cap <NUM> can include the same components as light-up cap <NUM> except rather than housing <NUM> being configured to attach to head <NUM>, housing <NUM> can be configured to attach to probe tip <NUM>. Housing <NUM> can include fingers <NUM> shaped to wrap around the ball shape of probe tip <NUM> and engage flush with extension <NUM>.

<FIG> is a block diagram illustrating components of sensory feedback fiducial marker cap <NUM>. Sensory feedback fiducial marker cap <NUM> can comprise housing <NUM>, circuit board <NUM>, processor <NUM>, memory <NUM>, switch <NUM>, input/output (I/O) device <NUM>, power source <NUM>, light sources 416A, 416B and 416C and wave generator <NUM>. Housing <NUM> can be attached or integral with fiducial marker fastener <NUM>.

Housing <NUM> can comprise a structural component to hold and support other components of fiducial marker cap <NUM>. Housing <NUM> can be integral with a fiducial marker fastener, such as fasteners <NUM> and <NUM>. However, in other examples, housing <NUM> can include a compartment for receiving the components of fiducial marker cap <NUM>, as well as a socket, e.g., socket <NUM>, for receiving another component of surgical system <NUM>, such as probe tip <NUM> or the head of a fiducial marker fastener, such as heads <NUM> and <NUM>, and an access port, e.g., access port <NUM>, for receiving the other of the probe tip of the fastener head. Housing <NUM> can be made of a medical grade plastic material, or can be made of other medical grade materials, such as stainless steel. Housing <NUM> can be made of a transparent or translucent material to facilitate transmission of light through housing <NUM> to improve visibility of any light sources disposed in or on housing <NUM>, such as light sources 416A - 416C.

Circuit board <NUM> can comprise a structural component for coupling electrical components of fiducial marker cap <NUM>. For example, circuit board <NUM> can comprise a silicon wafer into which electrical couplings are attached for coupling switch <NUM>, processor <NUM>, memory <NUM> and the like.

Processor <NUM> can comprise an integrated circuit that controls operation of components of fiducial marker cap <NUM>, such as switch <NUM>, I/O device <NUM> and light sources 416A, 416B and 416C.

Memory <NUM> can comprise any suitable storage device, such as non-volatile memory, magnetic memory, flash memory, volatile memory, programmable read-only memory and the like. Memory <NUM> can include instructions stored therein for processor <NUM> to control operation of fiducial marker cap <NUM>. For example, memory <NUM> can include instructions for lengths of time for which to activate light sources 416A - 416C; when switch <NUM> is activated, for colors of light sources 416A - 416C and the sequence in which to activate light sources 416A - 416C.

Switch <NUM> can comprise a an on/off switch for providing power from power source <NUM> to light sources 416A - 416C. Switch <NUM> can comprise an "alternate action" switch or a "momentary action" switch when transitioning between open or closed states. In alternate action switches, a switch can be flipped for continuous "on" or "off" operation. In momentary action switches, a switch can be activated or engaged for "on" operation and released for "off" operation. As such, switch <NUM> can comprise a toggle switch, a knife switch, a relay or a pushbutton switch. Switch <NUM> can include means, such as spring <NUM>, for returning switch <NUM> to a released or "off" position from an engaged or "on" position.

I/O device <NUM> can comprise one or more devices for receiving input from surgical system <NUM> or providing an output to surgical system <NUM> via signal <NUM>. I/O device <NUM> can provide signal <NUM> to computing system <NUM> of surgical system <NUM> indicating the state of switch <NUM> or light sources 416A - 416C. Computing system <NUM> can thereafter, for example, display on human interface device <NUM>, such as a video display monitor, an indication of when fiducial marker cap <NUM> has been engaged. Computing system <NUM> can also be configured to provide an auditory signal or alarm for when fiducial marker cap <NUM> has been engaged after receiving signal <NUM>. Signal <NUM> can additionally comprise or include data relating to the number of times or the length of time that switch <NUM> has been engaged. I/O device <NUM> can receive signal <NUM> from computing system <NUM> for storing information on memory <NUM> or providing information to processor <NUM> for operating switch <NUM> and light sources 416A - 416C. For example, computing system <NUM> can program fiducial marker cap <NUM> for the length of time to activate light sources 416A - 416C, the colors for activating light sources 416A - 416C, or sounds to produce with I/O device <NUM>. In examples, I/O device <NUM> can communicate using wireless communications signals, such as Bluetooth, WiFi, Zigbee, infrared (IR), near field communication (NFC), 3GPP or other technologies.

Power source <NUM> can comprise an energy storage device such as a battery including an electrochemical cell, such as an alkaline or zinc-manganese battery. Power source <NUM> can be rechargeable.

Light sources 416A - 416C can comprise one or more devices for producing light waves <NUM>, such as incandescent light bulbs, light-emitting-diodes and the like. In examples, light sources 416A - 416C can comprise separate light emitting devices integrated into a single device and each can be configured for emitting a different color or wavelength of light. In examples, light sources 416A - 416C can comprise a single light-emitting device configured for emitting a plurality of different colors or wavelengths. As discussed herein, light sources 416A - 416C can provide visual indications of when fiducial markers are engaged by a robotic surgical system when performing a registration process. For example, light sources 416A - 416C can be configured to emit orange, yellow and green light, respectively. In an example, the first time switch <NUM> is engaged, light source 416A can light up orange, the second time switch <NUM> is engaged, light source 416B can light up yellow and light source 416A can shut off, and the third time switch <NUM> is engaged, light source 416C can light up green and light source 416B can shut off. As such, an operator can confirm that three consecutive engagements of fiducial marker cap <NUM> have been completed. In other example, a light source can be configured to light up red to indicate a condition of fiducial marker cap <NUM>, such as a loss of communication or a malfunction of switch <NUM>. In other examples, fiducial marker caps <NUM> attached to different fiducial marker fasteners can be configured to each light up a different color such that a surgeon can view a location-specific color for each fiducial marker.

Wave generator <NUM> can include or comprise a device such as for making wave <NUM>, such as a sound wave or a vibration wave. In an example, wave generator <NUM> can comprise an auditory device, such as a speaker or amplifier for producing an auditory signal or sound to indicate that fiducial marker cap <NUM> has been engaged. In other examples, wave generator <NUM> can comprise tactile device, such as a reciprocating or oscillating device, for producing a vibration that can be felt by a surgeon or operator of system <NUM>. For example, wave <NUM> can communicate with a device worn by a surgeon at computing system <NUM> that can vibrate when receiving wave <NUM>.

Sensory feedback fiducial marker cap <NUM> can thus be configured to provide one or more different types of sensory feedback to a surgeon or operator of surgical system <NUM> (<FIG>). The sensory feedback can comprise visual, auditory or tactile stimulus to the surgeon or operator. The sensory feedback can be electrically generated, such as with power from power source <NUM>. The sensory feedback can take on the form of a light wave, a sound wave, a vibration wave, or an electrical or communication signal. The sensory feedback can provide an indication or confirmation that probe tip <NUM> of robotic surgical arm <NUM> (<FIG>) has engaged a fiducial marker, such as fiducial marker fastener <NUM> or <NUM>. Receipt of the sensory feedback can allow the surgeon or operator to know that pointer probe <NUM> is in position for a location reading to be taken by computing system <NUM> for the location of the fiducial marker in a coordinate system for surgical system <NUM>, such as with a tracking element <NUM>.

Sensory feedback fiducial marker cap <NUM> and the other fiducial marker caps described herein can be disposable or can be reusable. For example, housings <NUM> and <NUM> can be separable from fasteners so that each component can be cleaned. Housing <NUM> can include seal <NUM> to prevent cleaning fluid from reaching electrical components within housing <NUM>. In examples, the various housings described herein can include separable components such that the electrical component located therein can be accessed, such as to change power source <NUM>. In other examples, power source <NUM> can be wirelessly charged through a housing. However, in order to reduce the cost of manufacturing each sensory feedback fiducial marker cap described herein, they can be configured as one-time-use items.

<FIG> is a flowchart illustrating actions or steps of method or technique <NUM> for registering an anatomy to a robot-assisted surgical system, such as surgical system <NUM> of <FIG>, in accordance with the systems and methods relating to fiducial markers with feedback described herein.

At step <NUM>, fiducial marker fasteners, such as fasteners <NUM> and <NUM> can be implanted into or onto a patient, such as patient <NUM> (<FIG>). For example, fasteners <NUM> can be threaded into bone of skull <NUM> of patient <NUM>. A plurality of fasteners <NUM>, for example, can be implanted into skull <NUM> at anatomic locations to mark the topology of skull <NUM> and anatomy, tissue or organs inside of skull <NUM>. Fasteners <NUM> can include sensory feedback fiducial marker caps described herein that are integrated into the fastener. However, in various embodiments, the sensory feedback fiducial marker caps can be attached to a component of surgical system <NUM>, such as fasteners <NUM> or pointer probe <NUM>, as a separate component from the fastener.

At step <NUM>, the patient with the implanted fiducial marker fasteners can be imaged to obtain imaging of the anatomy of the patient including the implanted fiducial marker fasteners. Multiple images can be obtained at different angles to show the anatomy relative to a plurality of fiducial marker fasteners in order to develop a three-dimensional map of the anatomy of the patient. The imaging can be obtained from any suitable medical imaging system, such as x-ray imaging, computed tomography (CT) imaging, magnetic resonance imaging, (MRI), ultrasonic imaging, sonographic imaging and the like. The imaging can be stored in surgical system <NUM>, such as at computing system <NUM> and can be viewed on human interface device <NUM>.

At step <NUM>, the patient and the fiducial marker fasteners can be moved into an operating room or surgical area, such as surgical area <NUM> (<FIG>). The patient can be positioned such that the anatomy where the fiducial marker fasteners are attached are accessible by surgical arm <NUM>. As such, the patient can be positioned within a virtual coordinate system for surgical system <NUM>.

At step <NUM>, one or more fiducial marker caps can be attached to a system component. For example, in an embodiment, light-up probe cap <NUM> can be attached to probe tip <NUM> of pointer probe <NUM> for use with multiple fiducial marker fasteners. In other examples, multiple light-up caps <NUM> can be attached to multiple fasteners <NUM>, or multiple light-up caps <NUM> can be attached to multiple fasteners <NUM><NUM>. In some situations, it can be advantageous or desirable to separately attach multiple light-up or sensory caps to fasteners. For example, suitable imaging of the anatomy of the patient can be obtained without the light-up or sensory caps and any interference that may be caused therefrom. For example, electrical components of cap <NUM> may cause electrical interference with the imaging system, or housing <NUM> may interfere with visibility of head <NUM> of fastener <NUM> in the obtained images.

At step <NUM>, pointer probe <NUM> can be attached to robotic surgical arm <NUM>. Robotic surgical arm <NUM> can be operated, such as by causing rotation about axes 216A - 216D using computing system <NUM>, to bring pointer probe <NUM> proximate to one of the fiducial marker fasteners. In another example, a separate pointer probe instrument can be tracked by an optical tracking system to enable the registration process. In this example, robotic surgical arm <NUM> can be separately registered into the same coordinate system using the optical tracking system. A separate tracked pointer probe instrument can function in a similar manner to pointer probe <NUM>, while the optical tracking system tracks location and orientation from tracking markers affixed to the tracked pointer probe instrument.

At step <NUM>, pointer probe <NUM> can be advanced toward a fiducial marker cap, or a fiducial marker fastener. For example, robotic surgical arm <NUM> can position pointer probe <NUM> so that probe tip <NUM> is positioned opposite a surface of a fiducial marker cap, such as end surface <NUM> of cap <NUM> (<FIG>), including a switch or an access opening for a switch. In other examples, robotic surgical arm <NUM> can position a fiducial marker cap, such as cap <NUM> (<FIG>) attached to probe tip <NUM> opposite a fiducial marker head, such as head <NUM> or <NUM>.

At step <NUM>, probe tip <NUM>, the fiducial marker cap and the fiducial marker fastener can be aligned. In an example, probe tip <NUM> of pointer probe <NUM> can be centered on a fiducial marker cap housing. In order to facilitate the centering, probe tip <NUM> can be positioned within an access port of cap housing, such as access port <NUM>. The geometry of the access port and the location of the access port in the housing can center probe tip <NUM> on the fiducial marker fastener. In other examples, probe tip <NUM> with cap <NUM> can be centered on head <NUM> of fastener <NUM>.

At step <NUM>, robotic surgical arm <NUM> can be manipulated to activate a switch within the fiducial marker cap. In an example, probe tip <NUM> can engage a switch within the fiducial marker cap, such as cap <NUM>. In another example, a head of a fiducial marker fastener can engage a switch within the fiducial marker cap, such as cap <NUM>. Reaction forces applied to probe tip <NUM> can be managed by computing system <NUM>. In some typical operating conditions, when a force is applied to probe tip <NUM>, arm <NUM> can be instructed to move in the direction of the force. Thus, for example, if probe tip <NUM> engaged a switch within a fiducial marker cap, probe tip <NUM> would be programmed to react by moving away from the fiducial marker cap. However, during the registration procedure, it might be advantageous to avoid such a rebound. As such, computing system <NUM> can be put in a registration mode where a force sensor could be used to detect the rebound and send a command signal to computing system <NUM> to not take into account this information and move arm <NUM>. Likewise, lateral forces applied to probe tip <NUM> can be managed by computing system <NUM> during the registration process. For example, if probe tip <NUM> unintentionally touches walls of the fiducial marker cap, e.g., walls of access port <NUM> of housing <NUM> in <FIG>, probe tip <NUM> would ordinarily be programmed to rebound, as described above, and could then engage the opposite wall of the fiducial marker cap causing a resonance effect where probe tip <NUM> could be continuously moved between opposing walls of the access port. Thus, computing system <NUM> can be put in a registration mode where such movements can be prevented via input from a force sensor that can be used to instruct computing system <NUM> to not react in such a resonance or bouncing manner.

At step <NUM>, the fiducial marker cap can be activated, such as by probe tip <NUM> or head <NUM> or head <NUM> engaging a switch. Activation of the fiducial marker cap can cause electronics of the fiducial marker cap to generate an electric or sensory signal. For example, an electric visual signal can be generated by a light emitting device, such as light sources 416A - 416C. In other examples, an electric audio signal can be produced by the sensory feedback fiducial marker cap. In other examples, an electric signal can be sent, such as by I/O device <NUM> to, for example, computing system <NUM> or a device worn by a surgeon or operator. In an example, computing system <NUM> can utilize force sensor <NUM> (<FIG>) to ensure or verify that robotic surgical arm <NUM> (<FIG>) pushes the switch with adequate force. Furthermore, in examples, information from force sensor <NUM> can be used to determine if probe tip <NUM> has properly engaged a fiducial marker without the aid of a separate switch signal. For example, computing system <NUM> can be put in a cooperative mode where signals from force sensor <NUM> can be detected when probe tip <NUM> contacts the fiducial marker. Additionally, positioning of probe tip <NUM> can be done using a mix of cooperative and automatic modes where an operator manually moves probe tip <NUM> in close proximity to the fiducial marker and then computing system <NUM> moves probe tip <NUM> into actual contact with the fiducial marker. In another mixed mode operation, probe tip <NUM> can be manually moved into contact with fiducial markers in order to generate a three-dimensional model of the fiducial markers that can permit computing system <NUM> to automatically position probe tip <NUM> in locations to contact the fiducial markers, such as for verification with a switch or sensor described herein. In yet another mixed mode operation, probe tip <NUM> can be manually moved into close proximity of the fiducial markers and further movement can be controlled incrementally, such as by use of a button or remote control, until computing system <NUM> determines that probe tip <NUM> is in the proper location using switch or sensor information described herein. As an alternative to using force sensor information, or in conjunction with using force sensor information, switch information or conduction/magnetic sensing, power consumption from motors for robotic arm <NUM> can be used to determine if probe tip <NUM> contacts a fiducial marker. Such power consumption information can be correlated to force information.

At step <NUM>, sensory feedback from the fiducial marker cap can be received by an operator of surgical system <NUM> either directly from the fiducial marker cap or from computing system <NUM>. For example, the sensory feedback can comprise a visual indicator, such as light wave <NUM> provided by a lit up light source, from the fiducial marker cap, an audio indicator, such as sound wave <NUM> provided by an auditory alarm, from the fiducial marker cap, or a visual or audio indicator from human interface device <NUM> provided by signal <NUM>.

At step <NUM>, after the sensory feedback has been received by the surgeon or operator or computing system <NUM>, a location for the fiducial marker fastener can be recorded. For example, when probe up <NUM> engages the fiducial marker cap, the orientation of robotic surgical arm <NUM> can be recorded in memory of computing system <NUM>. The orientation of robotic surgical arm <NUM> can be determined using, for example, tracking element <NUM> and the known geometry of pointer probe <NUM> or the orientation of segments of robotic surgical arm <NUM> relative to axes 216A - 216D and the known geometry of pointer probe <NUM>. The location can be manually recorded by a surgeon or operator using computing system <NUM>, or computing system <NUM> can automatically record the location when signal <NUM> is generated.

At step <NUM>, engagement of probe tip <NUM> with the fiducial marker cap can be confirmed. Confirmation can comprise withdrawing probe tip <NUM> from the fiducial marker cap and reengaging probe tip <NUM> with the fiducial marker cap. As such, method <NUM> can return to step <NUM> or another step of method <NUM> to receive additional sensory feedback and record another location for the fiducial marker fastener location.

In examples, a switch for the fiducial marker cap can remain activated such that the sensory feedback remains active. When the probe tip reactivates the switch, the sensory feedback can change. For example, the sensory feedback can change from a first color to a second color so a surgeon or operator can visually track the sequence of confirmation. In various embodiments, the confirmation can be repeated twice such that three data points can be collected for each fiducial marker fastener. In other examples, the switch for the fiducial marker cap can deactivate when the pointer probe disengages. Thus, the same sensory feedback can be provided for each time the pointer probe engages the fiducial marker cap and a surgeon or operator can manually keep track of the number of data points collected, such as with the aid of computing system <NUM>.

At step <NUM>, the fiducial marker cap can be deactivated, such as by withdrawing the pointer probe from the fiducial marker cap. Additionally, the fiducial marker cap can be reengaged by probe tip <NUM> to deactivate the fiducial marker cap. In other examples, the fiducial marker cap can be left activated. After the location for a fiducial marker is successfully recorded, robotic surgical arm <NUM> can be manipulated to repeat the process to record the location for another fiducial marker at a different location on the patient. As such, the process or method can return to step <NUM> or another step to repeat all of some of method <NUM>.

<FIG> illustrates system <NUM> for performing techniques described herein, in accordance with some embodiments. System <NUM> can include robotic surgical device <NUM> coupled to probe <NUM>, which may interact with fiducial marker <NUM>. Fiducial marker <NUM> can include sensory component <NUM>, switch component <NUM> and anchor component <NUM>. System <NUM> can include display device <NUM>, which can be used to display user interface <NUM>. System <NUM> can include control system <NUM> (e.g., a robotic controller), including processor <NUM> and memory <NUM>. In an example, display device <NUM> can be coupled to one or more of robotic surgical device <NUM>, probe device <NUM>, or control system <NUM>.

<FIG> illustrates a block diagram of an example machine <NUM> upon which any one or more of the techniques discussed herein may perform in accordance with some embodiments. In alternative embodiments, machine <NUM> may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, machine <NUM> may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, machine <NUM> may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. Machine <NUM> may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine.

Machine (e.g., computer system) <NUM> may include hardware processor <NUM> (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), main memory <NUM> and static memory <NUM>, some or all of which may communicate with each other via interlink (e.g., bus) <NUM>. Machine <NUM> may further include display unit <NUM>, alphanumeric input device <NUM> (e.g., a keyboard), and user interface (UI) navigation device <NUM> (e.g., a mouse). In an example, display unit <NUM>, input device <NUM> and UI navigation device <NUM> may be a touch screen display. Machine <NUM> may additionally include storage device (e.g., drive unit) <NUM>, signal generation device <NUM> (e.g., a speaker), network interface device <NUM>, and one or more sensors <NUM>, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. Machine <NUM> may include output controller <NUM>, such as a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

Storage device <NUM> may include machine readable medium <NUM> on which is stored one or more sets of data structures or instructions <NUM> (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. Instructions <NUM> may also reside, completely or at least partially, within main memory <NUM>, within static memory <NUM>, or within hardware processor <NUM> during execution thereof by machine <NUM>. In an example, one or any combination of hardware processor <NUM>, main memory <NUM>, static memory <NUM>, or storage device <NUM> may constitute machine readable media.

While machine readable medium <NUM> is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions <NUM>. The term "machine readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by machine <NUM> and that cause machine <NUM> to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media.

Instructions <NUM> may further be transmitted or received over communications network <NUM> using a transmission medium via network interface device <NUM> utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) <NUM> family of standards known as Wi-Fi®, IEEE <NUM> family of standards known as WiMax®), IEEE <NUM>. <NUM> family of standards, peer-to-peer (P2P) networks, among others. In an example, network interface device <NUM> may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to communications network <NUM>. In an example, network interface device <NUM> may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by machine <NUM>, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

The systems, devices and methods discussed in the present application can be useful in performing registration processes of fiducial markers with robotic surgical systems, such as by improving the accuracy of the registration process. In particular, the systems, devices and methods described herein facilitate more precise engagement between a pointer probe tip and a fiducial marker and better recognition of proper engagement between a pointer probe tip and the fiducial marker by an operator or surgeon. Such benefits can reduce error in the registration process, which can correlate to reduced error in performing a medical procedure on a patient.

The drawings show, by way of illustration, specific embodiments in which the disclosure can be practiced. However, the present inventor also contemplates examples in which only those elements shown or described are provided. Moreover, the present inventor also contemplates examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

Method examples described herein and not forming part of the present invention can be machine or computer-implemented at least in part.

Claim 1:
A fiducial marker comprising:
a fastener (<NUM>) comprising:
a threaded shaft (<NUM>) extending along an axis; and
a head (<NUM>) connected to the threaded shaft (<NUM>); and
a feedback component attached to the fastener (<NUM>), wherein the feedback component comprises:
a housing (<NUM>) attached to the head, the housing (<NUM>) comprising an access port (<NUM>) disposed in a first end of the housing (<NUM>);
a switch (<NUM>) disposed in the housing (<NUM>) proximate to the access port (<NUM>); and
a light source (<NUM>, <NUM>) electronically coupled to the switch (<NUM>),
characterized in that
the housing (<NUM>) is configured to couple to the head (<NUM>) of the fastener (<NUM>) to position switch (<NUM>) and access port (<NUM>) into axial alignment with the center axis of the fastener (<NUM>), and
wherein the feedback component is configured to provide a registration signal by emitting light from the light source (<NUM>, <NUM>) when the switch (<NUM>) is activated by a probe through the access port (<NUM>).