Latency-based control of surgical navigation systems

Abstract

Systems and methods for tracking surgical objects during a surgical procedure are configured in consideration of data latency. Tracking data indicative of a position of a powered surgical instrument relative to patient tissue to be treated is generated by a surgical navigation system. A system latency value associated with the tracking data is determined. An actuator of the powered surgical instrument is controlled based on the system latency value and a current position of the surgical instrument relative to the patient tissue indicated by the tracking data. Further, based on a position of the surgical instrument relative to a target site of the patient tissue to be treated that is indicated by the tracking data, tracking of surgical objects in the surgical workspace other than the surgical instrument and the target site is paused.

Description

LATENCY-BASED CONTROL OF SURGICAL NAVIGATION SYSTEMSRELATED APPLICATION(S)

[0001] This application claims priority to and all the benefits of U.S. Provisional Patent Application No. 63 / 654913 filed May 31, 2024, the entire disclosure of which is hereby incorporated by reference herein.BACKGROUND

[0002] Surgical navigation systems assist surgeons in the navigation of various objects during surgical procedures, such as sinus, spinal, and cranial surgeries. Typical surgical navigation systems are configured to track the poses of surgical devices, such as instruments and implants, relative to patient tissue of interest to a surgical procedure, and display information based on the tracked poses to guide the surgeon in performing the procedure. Some surgical navigation systems are configured to take a more active role in a surgical procedure, such as by being configured to control actuation of a surgical instrument based on the instrument’s tracked pose relative to the patient tissue of interest. For instance, when tracking data indicates a surgical instrument has contacted or is near contacting patient tissue to be avoided, these surgical navigation systems can stop actuation of the surgical instrument so as to prevent or reduce manipulation of such tissue.

[0003] The efficacy of a surgical navigation system depends at least in part on system latency. System latency can be affected by various factors, such as data communication rates and utilization of system resources. A need exists for improved navigation systems that operate in consideration of such factors.SUMMARY

[0004] This Summary introduces a selection of concepts in a simplified form that are further described in the Detailed Description below. This Summary is not intended to limit the scope of the claimed subject matter nor identify key features or essential features of the claimed subject matter.

[0005] One general aspect includes a system for controlling operation of a powered surgical instrument for treating patient tissue as a function of tracking data latency. The system includesa tracker configured to be attached to the powered surgical instrument for treating patient tissue. The system also includes a navigation system configured to cooperate with the tracker to generate tracking data indicative of a position of the powered surgical instrument relative to the patient tissue. The system also includes at least one controller coupled to the powered surgical instrument and configured to: determine a system latency value associated with the tracking data generated by the navigation system, determine at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data, and control an actuator of the powered surgical instrument based on the system latency value and the at least one spatial movement characteristic.

[0006] Another general aspect includes a system for controlling operation of a powered surgical instrument as a function of navigation data latency. The system includes a tracker configured to be attached to the powered surgical instrument for treating patient tissue. The system also includes a navigation system configured to cooperate with the tracker to generate tracking data indicative of a position of the powered surgical instrument relative to the patient tissue. The system also includes at least one controller coupled to the powered surgical instrument and configured to: retrieve a predefined system latency value associated with the tracking data; determine at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data generated by the navigation system; and control an actuator of the powered surgical instrument based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the predefined system latency value.

[0007] Another general aspect includes a method for controlling operation of a powered surgical instrument for treating patient tissue as a function of navigation data latency. The method includes generating, by a navigation system configured to cooperate with a tracker attached to the powered surgical instrument, tracking data indicative of a position of the powered surgical instrument relative to the patient tissue. The method also includes determining, by at least one controller coupled to the powered surgical instrument, a system latency value associated with the tracking data generated by the navigation system. The method also includes determining, by the at least one controller, at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data. The method also includes controlling, by the at least one controller, an actuatorof the powered surgical instrument based on the system latency value and the at least one spatial movement characteristic.

[0008] Another general aspect includes a method for controlling operation of a powered surgical instrument for treating patient tissue as a function of navigation data latency. The method includes generating, by a navigation system configured to cooperate with a tracker attached to the powered surgical instrument, tracking data indicative of a position of the powered surgical instrument relative to the patient tissue. The method also includes retrieving, by at least one controller coupled to the powered surgical instrument, a predefined system latency value associated with the tracking data. The method also includes determining, by the at least one controller, at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data generated by the navigation system. The method also includes controlling, by the at least one controller, an actuator of the powered surgical instrument based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the predefined system latency value.

[0009] Another general aspect includes a system for navigating a plurality of surgical instruments relative to patient tissue including a target site to be treated during a surgical procedure. The system includes a first instrument tracker and a second instrument tracker configured to be attached to a first surgical instrument and a second surgical instrument respectively. The system also includes a localizer configured to cooperate with the first and second instrument trackers to generate localization data indicative of a position of each of the first and second surgical instruments relative to the target site in a known coordinate system. The system also includes at least one controller coupled to the tracking unit and configured to: define a virtual treatment zone relative to the target site in the known coordinate system; track the position of both the first and second surgical instruments relative to the target site based on the localization data; determine whether the first surgical instrument enters the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument enters the virtual treatment zone, pause the tracking of the position of the second surgical instrument relative to the target site while continuing to track the position of the first surgical instrument relative to the target site.

[0010] Another general aspect includes a system for navigating a surgical instrument relative to patient tissue including a plurality of target sites to be treated during a surgical procedure. The system includes a first patient tracker and a second patient tracker configured to be attached to the patient tissue for tracking a first target site of the patient tissue to be treated and a second target site of the patient tissue to be treated respectively. The system also includes an instrument tracker configured to be attached to a surgical instrument for treating the first and second target sites. The system also includes a localizer configured to cooperate with the first and second patient trackers and the instrument tracker to generate localization data indicative of a position of the surgical instrument relative to the first and second target sites in a known coordinate system. The system also includes at least one controller coupled to the localizer and configured to: define a first virtual treatment zone relative to the first target site and a second virtual treatment zone relative to the second target site in the known coordinate system; track the position of the surgical instrument relative to both the first and second target sites based on the localization data; determine whether the surgical instrument enters the first virtual treatment zone based on the localization data; and responsive to determining that the surgical instrument enters the first virtual treatment zone, pause the tracking of the position of the surgical instrument relative to the second target site while continuing to track the position of the surgical instrument relative to the first target site.

[0011] Another general aspect includes a method for navigating a plurality of surgical instruments relative to patient tissue including a target site to be treated during a surgical procedure. The method includes generating, by a localizer configured to cooperate with first and second instrument trackers attached to first and second surgical instruments respectively, localization data indicative of a position of each of the first and second surgical instruments relative to the target site in a known coordinate system. The method also includes defining, by at least one controller coupled to the localizer, a virtual treatment zone relative to the target site in the known coordinate system. The method also includes tracking, by the at least one controller, the position of both the first and second surgical instruments relative to the target site based on the localization data. The method also includes determining, by the at least one controller, that the first surgical instrument enters the virtual treatment zone based on the localization data. The method also includes responsive to determining that the first surgical instrument enters the virtual treatment zone, pausing, by the at least one controller, the trackingof the position of the second surgical instrument relative to the target site while continuing to track the position of the first surgical instrument relative to the target site.

[0012] Another general aspect includes a method for navigating a surgical instrument relative to patient tissue including a plurality of target sites to be treated during a surgical procedure. The method includes generating, by a localizer configured to cooperate with first and second patient trackers attached to the patient tissue for tracking a first target site of the patient tissue to be treated and a second target site of the patient tissue to be treated respectively and an instrument tracker attached to a surgical instrument for treating the first and second target sites, localization data indicative of a position of the surgical instrument relative to the first and second target sites in a known coordinate system. The method also includes defining, by at least one controller coupled to the localizer, a first virtual treatment zone relative to the first target site and a second virtual treatment zone relative to the second target site in the known coordinate system. The method also includes tracking, by at least one controller, the position of the surgical instrument relative to both the first and second target sites based on the localization data. The method also includes determining, by at least one controller, that the surgical instrument enters the first virtual treatment zone based on the localization data. The method also includes responsive to determining that the surgical instrument enters the first virtual treatment zone, pausing, by at least one controller, the tracking of the position of the surgical instrument relative to the second target site while continuing to track the position of the surgical instrument relative to the first target site.

[0013] Other general aspects include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform one or more steps of any one or more of the above methods. For instance, a computer system or apparatus may include at least one processor and at least one memory device storing computer-executable instructions that, upon execution by the at least one processor, cause the at least one processor to perform one or more steps of any one or more of the above methods. As a further example, a computer program product may include a non-transitory computer readable storage medium that stores computer-executable instructions which, upon execution by at least one processor, causes the at least one processor to perform one or more steps of any one or more of the above methods.

[0014] Any of the above aspects can be combined in part or in whole with any other aspect. Any of the above aspects, whether combined in part or in whole, can be further combined with any of the implementations discussed in the Detailed Description below.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following Detailed Description when considered in connection with the accompanying drawings.

[0016] FIG. 1 is a schematic view of a surgical system including a plurality of surgical instrument assemblies and a surgical navigation system for tracking a surgical instrument associated with each of the various surgical instrument assemblies.

[0017] FIG. 2 is a perspective view of an exemplary layout of an operating room including at least one surgical instrument assembly and a surgical navigation system for performing a surgical procedure on a patient.

[0018] FIG. 3 illustrates a method for controlling actuation of a surgical instrument based on the tracked pose of the surgical instrument relative to a virtual boundary associated with patient tissue to be avoided and a latency of the surgical system.

[0019] FIG. 4 is a schematic view of a patient vertebra including a target site of patient tissue to be treated and a surgical instrument oriented for placement into the vertebra to a selected depth.

[0020] FIG. 5 illustrates a method for operating a surgical navigation system so as to improve tracking performance during discrete steps of a surgical procedure.

[0021] FIG. 6 is a schematic view of a patient vertebra including multiple target sites of patient tissue to be treated and a virtual bounding box defined relative to each target site for detecting discrete steps of a surgical procedure.DETAILED DESCRIPTION

[0022] Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, FIG. 1 illustrates an exemplary surgical system 10 that may include a surgical navigation system 100 for tracking one or more surgical objects during a surgical procedure, such as patient tissue and one or more surgical instrument assemblies 200,300, 400. Each surgical instrument assembly 200, 300, 400 may include a surgical instrument 220, 320, 420 to assist the medical professional, such as a surgeon, in executing the surgical procedure.

[0023] The surgical navigation system 100 may include a navigation controller 140 and a user interface coupled to the navigation controller 140. The user interface may include one or more display units 120 and one or more user input devices 130. The display unit(s) 120 of the surgical navigation system 100 may be driven by the navigation controller 140, and to this end may be configured to display graphical user interfaces (GUIs) including information related to a current surgical procedure, and / or various elements, prompts or data entry boxes for interaction by the user, such as via the user input device(s) 130. In some implementations, the user input device(s) 130 may include a touch screen interface integrated with the display unit(s) 120. For example, the display unit(s) 120 may be configured to display a text box or prompt that allows the surgeon to manually enter or select the type of surgical procedure to be performed. The display unit(s) 120 may also be configured to display patient data, such as preoperative and / or intraoperative patient images of patient tissue of interest and / or virtual models of the patient tissue of interest developed from such images. The patient images may be based on MRI scans, radiological scans or computed tomography (CT) scans of the patient's anatomy. The display unit(s) 120 may be further configured to display a surgical plan for a surgical procedure, such as overlaid on the patient data.

[0024] The surgical plan may include information related to the type of surgical procedure being performed, the patient tissue of interest (e.g., target sites defining patient tissue to be treated, patient tissue to be avoided, anatomical structures including target sites and / or patient tissue to be avoided), the types of surgical devices (e.g., instruments and / or implants) to be used during the surgical procedure, and / or operating settings for the surgical navigation system 100. The surgical plan may also include planned trajectories for surgical devices relative to the patient tissue of interest, and / or may include target poses for implants or other medical devices to be implanted during the surgical procedure relative to the patient tissue of interest. The display unit(s) 120 may be configured to display at least a portion of the surgical plan, such as the planned trajectories and / or target poses, on the patient data, such as overlaid on patient images of the patient tissue of interest and / or relative to virtual models representativeof the patient tissue of interest, so as to assist the surgeon to visualize and / or implement the surgical plan.

[0025] It is contemplated that the surgical navigation system 100 may be configured to display and / or project a holographic image of at least a portion of the surgical plan, such as the planned trajectories and / or target poses, on surfaces in the operating room, such as surfaces of the patient tissue of interest. It is also contemplated that the surgical navigation system 100 may be configured to display and / or project a holographic image of at least a portion of the surgical plan on a head unit worn by the surgeon, such as a lens, shield, or glasses of the head unit. An exemplary configuration of a surgical navigation system 100 including a display unit worn by the surgeon to display planned trajectories and / or target poses is disclosed in International Patent Application No. PCT7IB2018 / 053130, the entirety of which is hereby incorporated by reference herein.

[0026] The user input device(s) 130 may allow the user to interact with the GUIs displayed on the display unit(s) 120 to input or modify the surgical plan. As an example, the user may interact with the user input device(s) 130 to define patient tissues of interest to a surgical procedure in patient images of the patient, such as patient tissue to be treated and thus defining a target site for the surgical procedure, and patient tissue to be avoided. The patient tissue to be avoided may include critical anatomical structures such as cortical walls, nerves, blood vessels or similar critical anatomical structures that the surgeon wishes to avoid. As described in more detail below, a user may further interact with the user input device(s) 130 to establish virtual objects defining zones surrounding the patient tissue of interest, which may be used by the surgical navigation system 100 to provide guidance for the surgical procedure. The user may also interact with the user input device(s) 130 to select surgical devices to be used in the surgical procedure, and / or select trajectories and / or target poses for the surgical devices, such as a target depth relative to the patient tissue of interest.

[0027] The user input device(s) 130 may also allow the user to interact with the GUIs displayed on the display unit(s) 120 to input or modify the patient data, which may include the patient images of the patient tissue of interest, boundaries of the patient tissue of interest relative to the patient images, and virtual models representative of the patient tissue of interest, such as developed from the patient images based on the identified boundaries. As an example, the user may interact with the user input device(s) 130 to identify and / or adjust boundaries of the patienttissue of interest within the patient images. The user may also identify and / or adjust dimensions of the patient tissue of interest, and / or create and / or adjust the virtual models representative of such patient tissue, as described in more detail below.

[0028] The surgical navigation system 100 may be configured to utilize segmentation of the patient images to identify boundaries of patient tissue of interest, and to facilitate the generation of virtual objects for guiding movement of a surgical instrument as described herein. This segmentation may be performed automatically, semi-automatically, or manually. In one example of manual segmentation, the surgeon may utilize the user input device(s) 130 to define a geometric primitive to define a region of interest. A method of defining geometric primitives for the purpose of segmentation and visualization of cavities or orifices of the human body may comprise the steps of: manual pre-segmentation by defining enclosing geometric primitives in a 3D patient image for generating initial envelopes; analyzing the anatomy within the pre-segmented geometric primitives; using the result of the analysis for adjustment of the envelopes; and visualizing the envelopes. Analysis of the anatomy within a pre-segmented geometric primitive may include computing cell affiliations of voxels within the presegmented geometric primitive, and the adjustment of a visualized envelope may be achieved by computing a surface mesh of the voxels which are affiliated completely and / or partially to a given cell. Further, the adjustment of a visualized envelope may be achieved by optimizing the type, orientation, position and / or size of the enclosing geometric primitive. Exemplary methods and systems for defining a geometric primitive and guiding a surgical instrument based thereon are disclosed in U.S. Patent Appl. No. 15 / 300,414 and U.S. Patent Appl. No. 15 / 582,637, both of which are hereby incorporated by reference herein in their entirety.

[0029] The navigation controller 140 may be configured to implement the functions, features and processes of the surgical navigation system 100 described herein. In one example, the navigation controller 140 may include a processor, memory, and non-volatile storage. The processor may include one or more devices selected from microprocessors, micro-controllers, digital signal processors, microcomputers, central processing units, field programmable gate arrays, programmable logic devices, state machines, logic circuits, analog circuits, digital circuits, and / or any other devices that manipulate signals (analog or digital) based on operational instructions read into the memory from the non-volatile storage. The memory may include a single memory device or a plurality of memory devices including, but not limited to,read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, and / or any other device capable of storing information. The non-volatile storage may include one or more persistent data storage devices such as a hard drive, optical drive, tape drive, non-volatile solid state device, and / or any other device capable of persistently storing information.

[0030] The navigation controller 140 may operate under control of surgical navigation software, such as embodied by computer-executable instructions residing in the non-volatile storage, including one or more modules and / or operating instructions. The surgical navigation software, upon execution by the navigation controller 140, may be configured to cause the navigation controller 140 to implement the various functions, features, and processes of the surgical navigation system 100 disclosed herein.

[0031] As one example, the surgical navigation software may include software configured to control operation of the surgical instruments 220, 320, 420. Such software may include a boundary generator. An exemplary system for and method of boundary generation may be found in U.S. Patent Publ. No. 2004 / 0034283 Al, which is hereby incorporated by reference herein in its entirety.

[0032] The boundary generator may be a software program or module configured to generate one or more virtual boundaries for constraining movement and / or operation of the surgical instruments 220, 320, 420 relative to the patient tissue of interest. In some examples, the boundary generator may provide one or more virtual boundaries that define a virtual drill and / or driver guide (e.g., a virtual implant planning guide). Virtual boundaries may also be provided to control operation of the surgical instruments 220, 320, 420 relative to patient tissue to be avoided, and / or to set target depths and / or target positions relative to the patient tissue of interest. The virtual boundaries may be one-dimensional (ID), two-dimensional (2D), three- dimensional (3D), and may comprise a point, line, axis, trajectory, plane (an infinite plane or plane segment bounded by the anatomy or other boundary), volume or other shapes, including complex geometric shapes. The virtual boundaries may be represented by pixels, point clouds, voxels, triangulated meshes, other 2D or 3D models, combinations thereof, and the like. U.S. Patent Publication No. 2018 / 0333207 and U.S. Patent No. 8,898,043 are hereby incorporatedby reference herein in their entirety, and any of their features may be used to facilitate planning or execution of the surgical procedure.

[0033] Boundaries to ensure that surgical devices are positioned at a desired depth may be defined by a virtual planar boundary, a virtual volumetric boundary, or other forms of virtual boundary. Virtual boundaries may also be referred to as virtual objects. The virtual boundaries may be defined with respect to a virtual model of patient tissue of interest, such as an anatomical structure defining a target volume (which may also be referred to as a target site) of patient tissue to be treated. In other words, the points, lines, axes, trajectories, planes, volumes, and the like that are associated with the virtual boundaries may be defined in a coordinate system that is fixed relative to a coordinate system of such virtual model such that tracking of the virtual model (e.g., via tracking the associated patient tissue to which it is registered) also enables tracking of the virtual boundary.

[0034] The virtual models of patient tissue of interest may each be registered to a patient tracker disposed relative to the patient tissue in the surgical workspace such that the virtual boundaries associated with the virtual model, or more particularly with the coordinate system of the virtual model, are also associated with the tracker. The virtual boundaries may be implant-specific (e.g., defined based on a size, shape, volume, etc. of a planned implant) and / or patient-specific (e.g., defined based on the patient’s anatomy). The virtual boundaries may be created pre-operatively, intra-operatively, or combinations thereof. In other words, the virtual boundaries may be defined before the surgical procedure begins, during the surgical procedure (including during tissue removal), or combinations thereof. The virtual boundaries may be provided in numerous ways, such as by the navigation controller 140 creating them, receiving them from other sources / sy stems, or the like. The virtual boundaries may be stored in memory for retrieval and / or updating.

[0035] It is contemplated that in some cases, the virtual boundaries may comprise multiple planar boundaries used to delineate multiple target depths (e.g., three target depths) for separate instruments to be used in a single procedure. For example, the virtual boundaries may include a first virtual boundary representing a target depth for a drill to bore a hole, a second virtual boundary representing a target depth for a tap, and a third virtual boundary representing a target depth for a driver to insert a screw. These multiple virtual boundaries can be activated, one at a time, by the navigation controller 140 to constrain cutting to one plane at a time.

[0036] The navigation controller 140 may track the poses of the surgical instruments 220, 320, 420 relative to the virtual boundaries. To this end, the surgical navigation system 100 may include a tracking unit 110 including one or more sensors 115. The sensors 115 may comprise cameras, such as CCD cameras, CMOS cameras, and / or optical image cameras, magnetic sensors, radio frequency sensors, or any other sensor adapted to detect and / or sense the position of instrument tracking devices 230, 330, 430, also referred to as instrument trackers, of the surgical instrument assemblies 200, 300, 400, and also to detect and / or sense the position of the patient tracking devices, also referred to as patient trackers, described above. Description of a suitable tracking unit 110, and the various localizers that it can utilize, may be found in U.S. Patent Publication No. 2017 / 0333137, which is hereby incorporated by reference herein in its entirety.

[0037] Various exemplary surgical instrument assemblies 200, 300, 400 are illustrated in communication with the surgical navigation system 100. The surgical instrument assemblies 200, 300, 400 may be configured to be in wired and / or wireless communication with the surgical navigation system 100. Each of the surgical instrument assemblies 200, 300, 400 may have a number of similar components capable of performing similar functions and / or operations. Similar components between each of the various surgical instrument assemblies 200, 300, 400 will include the same two-digit number with a leading 2, 3, or 4 to reflect the associated surgical instrument assembly 200, 300, 400. For example, each of the surgical instrument assemblies 200, 300, 400 may include a surgical instrument 220, 320, 420.

[0038] The surgical system 10 may comprise a first surgical instrument assembly 200 in communication with the surgical navigation system 100. The first surgical instrument assembly 200 may include a first surgical instrument 220, such as a surgical drill or driver, including a handpiece 225. The handpiece 225 may comprise a housing 210 configured to house the components of the first surgical instrument 220. The handpiece 225 may be shaped to define a handle or grip portion for the surgeon to hold while performing a medical procedure. Suitable handpieces are described in U.S. Patent No. 5747953, which is hereby incorporated by reference herein in its entirety.

[0039] The first surgical instrument 220 may further comprise a first instrument controller 215 and an actuator 245, the latter of which may be realized as a motor. Each of the first instrument controller 215 and the actuator 245 may be disposed within the handpiece 225 of the firstsurgical instrument 220. The first instrument controller 215 and the actuator 245 may be in communication with one another, and the first instrument controller 215 may be configured to control the operation of the actuator 245, and by extension the first surgical instrument 220. For example, the first surgical instrument 220 may comprise an end-effector 240, such as a drill bit for boring a hole or a driver for inserting a screw. The end-effector 240 may be coupled to the handpiece 225 of the first surgical instrument 220 such that the actuator 245 may be operably coupled to the end-effector 240. For example, the actuator 245 may be configured to rotate the end-effector 240 when realized as a drill bit to bore a hole and / or remove biological tissue.

[0040] The first instrument controller 215 may thus be configured to control operation of the end-effector 240 by controlling operation of the actuator 245. The first instrument controller 215 may also be in communication with the navigation controller 140. The controllers 140, 215 may be configured to exchange data related to the pose (e.g., position and orientation) of the first surgical instrument 220, and / or data and / or instructions related to the operation of the first surgical instrument 220. For example, the navigation controller 140 may be configured to communicate instructions for controlling operation of the first surgical instrument 220 to the first instrument controller 215 based on the pose of the first surgical instrument 220 as detected by the surgical navigation system 100.

[0041] The first surgical instrument assembly 200 may also comprise a power source 260. The power source 260 may be removably coupled to the handpiece 225 of the surgical instrument 220. For example, the power source 260 may comprise a removable battery pack. It is also contemplated that the power source 260 may be formed as part of, or disposed within, the handpiece 225 of the first surgical instrument 220. The power source 260 may be in electrical communication with the first instrument controller 215 and / or the actuator 245 and configured to selectively provide power to the actuator 245 to rotate the end-effector 240. The power source may also be a surgical console providing power to the first surgical instrument 220 with a cord.

[0042] The first surgical instrument assembly 200 may also comprise a first alert device 255. The first alert device 255 may comprise an audible, a tactile, and / or a visually perceptible device. The first alert device 255 may be configured to be in communication with the first instrument controller 215 or directly with the navigation controller 140. The first instrumentcontroller 215 or navigation controller 140 may be configured to send a signal to activate the first alert device 255 to provide a warning or notification based on a pre-programmed condition or setting.

[0043] The first surgical instrument assembly 200 may also comprise a tracking device 230. The tracking device 230 may be coupled to the handpiece 225 of the first surgical instrument 220. The tracking device 230 may comprise a plurality of markers 235 that are identifiable by the tracking unit 110 of the surgical navigation system 100. The markers 235 may comprise passive tracking elements (e.g., reflectors) for transmitting light signals (e.g., reflecting light emitted from the tracking unit 110) to the sensor(s) 115. In other configurations, the markers 235 may be configured as active tracking elements (e.g., LEDs). It is also contemplated that the markers 235 may comprise a combination of active and passive arrangements. The markers 235 may be arranged in a defined or known position and orientation relative to the first surgical instrument 220 to allow the surgical navigation system 100 to determine the pose of the first surgical instrument 220 relative to a known coordinate system, such as a coordinate system specific to the tracking unit 110, based on an identified pose of the tracking device 230 in the known coordinate system, which in turn may be determined based on positions of the markers 235 in the known coordinate system that are detected by the tracking unit 110. For example, the markers 235 may be registered to a coordinate system specific to the first surgical instrument 220 to allow the surgical navigation system 100 to determine the pose of the endeffector 240 or cutting portion of the first surgical instrument 220 relative to the virtual boundaries described herein, which may also be generated and tracked in the known coordinate system.

[0044] The surgical system 10 may also comprise a second surgical instrument assembly 300 to be used with the surgical navigation system 100. The second surgical instrument assembly 300 may comprise a second surgical instrument 320, such as a high-speed surgical bur, including a handpiece 325. The handpiece 325 may be coupled to a console 310 that is configured to control the operation of various components of the second surgical instrument 320. The handpiece 325 may be shaped to define a handle or grip portion for the surgeon to hold while performing a medical procedure. Exemplary second surgical instruments that connect to consoles may be found in U.S. Patent No. 10,016,209 and U.S. Patent Publication No. 2019 / 0117322, which are each hereby incorporated by reference herein in their entirety.

[0045] The second surgical instrument 320 may further comprise a second instrument controller 315 and an actuator 345, the latter of which may be realized as a motor. The second instrument controller 315 may be disposed within the console 310 of the second surgical instrument assembly 300. The actuator 345 may be disposed within the handpiece 325 of the second surgical instrument 320. The second instrument controller 315 and the actuator 345 may be in communication with one another, and the second instrument controller 315 may be configured to control the operation of the actuator 345, and by extension the second surgical instrument 320. For example, the second surgical instrument 320 may be coupled to the console by a cord connecting the second instrument controller 315 to the actuator 345 to allow communication between the second instrument controller 315 and the actuator 345 to control operation of the actuator.

[0046] The second instrument controller 315 may also comprise an end-effector 340, such as a high-speed cutting bur. The end-effector 340 may be coupled to the handpiece 325 of the second surgical instrument 320 such that the actuator 345 may be operably coupled to the endeffector 340. For example, the actuator 345 may be configured to actuate the end-effector 340 when realized as a high-speed cutting bur to grind and / or remove biological tissue from the surgical site. The second instrument controller 315 may thus be in communication with the actuator 345 and configured to control the operation of the actuator 345, and by extension the end-effector 340.

[0047] The second instrument controller 315 may also be in communication with the navigation controller 140. The controllers 140, 315 may be configured to exchange data related to the pose of the second surgical instrument 320, and / or data and / or instructions related to the operation of the second surgical instrument 320. For example, the navigation controller 140 may be configured to communicate instructions for controlling operation of the second surgical instrument 320 to the second instrument controller 315 based on the pose of the second surgical instrument 320 as detected by the surgical navigation system 100. It is also contemplated that additional surgical instruments may be coupled to the console 310 and / or in communication with the second instrument controller 315 disposed within the console 310.

[0048] The second surgical instrument assembly 300 may also comprise a power source. The power source may be coupled to the console 310 of the second surgical instrument assembly 300 and configured to provide energy to the actuator 345 of the second surgical instrument 320to actuate the end-effector 340. It is also contemplated that the console 310 may comprise a cord configured to be plugged into an outlet that is connected to an electrical grid for supplying energy to the second surgical instrument assembly 300. The power source may be in electrical communication with the second instrument controller 315 and / or the actuator 345 and configured to selectively provide power to the actuator 345 to actuate the end-effector 340.

[0049] The second surgical instrument assembly 300 may also comprise a second alert device 355. The second alert device 355 may comprise an audible, a tactile, and / or a visually perceptible device. The second alert device 355 may be configured to be in communication with the second instrument controller 315 or directly with the navigation controller 140. The second instrument controller 315 or navigation controller 140 may be configured to send a signal to activate the second alert device 355 to provide a warning or notification based on a pre-programmed condition or setting. In some implementations, the second alert device 355 may be at least partially disposed in a footswitch 350 of the third surgical instrument assembly 300, which may be for user control of the second surgical instrument 320. In this case, the second alert device 355 may include a tactile device that outputs vibrations to be felt in the user’s foot.

[0050] The second surgical instrument assembly 300 may also comprise a tracking device 330. The tracking device 330 may be coupled to the handpiece 325 of the second surgical instrument 320. The tracking device 330 may be similar to as described above for the first surgical instrument assembly 200. For instance, the tracking device 330 may include markers 335 arranged in a defined or known position and orientation relative to the second surgical instrument 320 to allow the surgical navigation system 100 to determine the pose of the second surgical instrument 320 relative to a known coordinate system, such as a coordinate system specific to the tracking unit 110, based on an identified pose of the tracking device 330 in the known coordinate system, which in turn may be determined based on positions of the markers 335 in the known coordinate system that are detected by the tracking unit 110. As an example, the markers 335 may be registered to a coordinate system specific to the second surgical instrument 320 to allow the surgical navigation system 100 to determine the pose of the endeffector 340 of the second surgical instrument 320 relative to the virtual boundaries described herein, which like the tracking device 330 may also be generated and tracked in the known coordinate system.

[0051] The surgical system 10 may also comprise a third surgical instrument assembly 400 in communication with the surgical navigation system 100. The third surgical instrument assembly 400 may comprise a third surgical instrument 420, such as an ultrasonic instrument, including a handpiece 425. The handpiece 425 may be coupled to a console 410 that is configured to control the operation of various components of the third surgical instrument 420. The handpiece 425 may be shaped to comprise a handle or grip portion for the surgeon to hold while performing a medical procedure.

[0052] The third surgical instrument 420 may further comprise a third instrument controller 415 and an actuator 445, the latter of which may be realized as an ultrasonic transducer. The third instrument controller 415 may be disposed within the console 410 of the third surgical instrument assembly 400. The actuator 445 may be disposed within the handpiece 425 of the third surgical instrument 420. The third instrument controller 415 and the actuator 445 may be in communication with one another.

[0053] The actuator 445 when realized as the ultrasonic transducer may comprise a piezoelectric element configured to expand and contract upon the application of an electric current to the piezoelectric element. The piezoelectric element may comprise a plurality of disc-shaped piezoelectric elements arranged end to end in a stack.

[0054] The third instrument controller 415 may be configured to control the operation of the actuator 445, and by extension the third surgical instrument 420. For example, the third surgical instrument 420 may comprise an end-effector 440, such as an ultrasonic tip assembly. The ultrasonic tip assembly may include a horn with an ultrasonic tip portion that vibrates at an ultrasonic wave velocity as the piezoelectric element(s) expand and contract. The ultrasonic tip assembly may also include an external sheath at least partially disposed over the horn except for the ultrasonic tip portion.

[0055] The end-effector 440 may be coupled to the handpiece 425 of the third surgical instrument 420 such that the actuator 445 may be operably coupled to the end-effector 440. For example, the actuator 445 may be configured to actuate the end-effector 440 when realized as the ultrasonic tip assembly to grind and / or remove biological tissue from the surgical site. The third instrument controller 415 may be in communication with the actuator 445 and configured to control the flow of electric current to the piezoelectric element(s), controlling operation of the actuator 445, and by extension the end-effector 440.

[0056] The third instrument controller 415 may also be in communication with the navigation controller 140. The controllers 140, 415 may be configured to exchange data related to the pose of the third surgical instrument 420, and / or data and / or instructions related to the operation of the third surgical instrument 420. For example, the navigation controller 140 may be configured to communicate instructions for controlling operation of the third surgical instrument 420 to the third instrument controller 415 based on the pose of the third surgical instrument 420 as detected by the surgical navigation system 100.

[0057] The third surgical instrument assembly 400 may also comprise a power source. The power source may be coupled to the console 410 of the third surgical instrument assembly 400 and configured to provide energy to the actuator 445 of the third surgical instrument 420 to actuate the end-effector 440. For example, the power source may comprise a removable battery pack. It is also contemplated that the console 410 may comprise a cord configured to be plugged into an outlet that is connected to an electrical grid for supplying energy to the third surgical instrument assembly 400. The power source may be in electrical communication with the third instrument controller 415 and / or the actuator 445 and configured to selectively provide power to the actuator 445 to actuate the end-effector 440.

[0058] The third surgical instrument assembly 400 may also comprise a third alert device 455. The third alert device 455 may comprise an audible, a tactile, and / or a visually perceptible device. The third alert device 455 may be configured to be in communication with the third instrument controller 415 or directly with the navigation controller 140. The third instrument controller 415 or navigation controller 140 may be configured to send a signal to activate the third alert device 455 to provide a warning or notification based on a pre-programmed condition or setting. In some implementations, the third alert device 455 may be at least partially disposed in a footswitch 450 of the third surgical instrument assembly 400, which may be used for user control of the third surgical instrument 420. In this case, the third alert device 455 may include a tactile device that outputs vibrations to be felt in the user’s foot.

[0059] The third surgical instrument assembly 400 may also comprise a tracking device 430. The tracking device 430 may be coupled to the handpiece 425 of the third surgical instrument 420. The tracking device 430 may be similar as defined above for the other instrument assemblies. For instance, the tracking device 430 may include markers 435 arranged in a defined or known position and orientation relative to the third surgical instrument 420 to allowthe surgical navigation system 100 to determine the pose of the third surgical instrument 420 relative to a known coordinate system, such as a coordinate system specific to the tracking unit 110, based on an identified pose of the tracking device 430 in the known coordinate system, which in turn may be determined based on positions of the markers 435 in the known coordinate system that are detected by the tracking unit 110. As an example, the markers 435 may be registered to a coordinate system specific to the third surgical instrument 420 to allow the surgical navigation system 100 to determine the pose of the end-effector 440 of the third surgical instrument 420 relative to the virtual boundaries described herein, which like the tracking device 430 may also be generated and tracked in the known coordinate system.

[0060] The surgical instrument assemblies 200, 300, 400 described above are intended to be exemplary instruments and / or configurations within the surgical system 10 but are not intended to be limiting. Other types and forms of surgical instrument assemblies are contemplated. While a plurality of exemplary surgical instrument assemblies 200, 300, 400 are described as being a part of the surgical system 10 and in communication with the surgical navigation system 100, it is contemplated that the surgical system 10 may only comprise a single surgical instrument assembly 200, 300, 400 and a surgical navigation system 100. Furthermore, while the surgical system 10 illustrated in FIG. 1 includes three surgical instrument assemblies 200, 300, 400 and a single surgical navigation system 100, it is contemplated that the surgical system 10 may be configured to include any combination of surgical instrument assemblies 200, 300, 400, and / or surgical navigation systems 100. For example, the surgical system 10 may include a single surgical instrument assembly 200, 300, 400 and a plurality of surgical navigation systems 100. Further exemplary features of the surgical system 10 may include those of the system described in U.S. Patent Publication No. 2022 / 0338938A1, which is incorporated by reference herein in its entirety.

[0061] Referring to FIG. 2, an exemplary configuration of an operating room or surgical suite for performing a medical procedure on a patient 20 using the surgical system 10 described above is shown. The surgical system 10 including the surgical navigation system 100 and at least one of the surgical instrument assemblies 200, 300, 400 described above may be placed in the operating room surrounding the patient 20 and / or the surgical site 30 where the medical procedure is to be performed.

[0062] While only the second surgical instrument assembly 300 is illustrated in FIG. 2, it will be understood that this is only an exemplary configuration of the surgical system 10, and that it is contemplated that any number of surgical instrument assemblies 200, 300, 400 may be positioned within the operating room. As described above, the second surgical instrument assembly 300 may include the second surgical instrument 320 including the end-effector 340 and the tracking device 330. The tracking device 330 may include a plurality of markers 335 that are capable of being identified and / or tracked by the surgical navigation system 100. The second surgical instrument 320 may be coupled to the console 310 that is positioned away from the second surgical instrument 320. The second surgical instrument assembly 300 may also comprise a footswitch 350 that is positioned away from the patient 20 and that is coupled to the console 310. The footswitch 350 may be in communication with and / or provide user control over actuation of the second surgical instrument 320 via the second instrument controller 315 (FIG. 1) housed within the console 310.

[0063] While not previously discussed, it is also contemplated that the surgical system 10 may comprise an imaging system 500, such as CT or MRI imaging device. The imaging system 500 may comprise a scanner 510 and a display unit 520. The scanner 510 may be utilized to take an image of the surgical site 30 on the patient 20, which may include the patient tissue of interest, and display it on the display unit 520. For example, the scanner may comprise a C- arm configured to be rotated about the patient 20 to produce a plurality of images of the surgical site 30. The imaging system 500 may also comprise an imaging controller including software that, upon execution by the imaging controller, is configured to cause the imaging controller to operate the scanner 510 to capture a plurality images and produce a 2-D and / or a 3-D image of the surgical site 30 based on the images. The imaging controller may be configured to display the resulting image on the display unit 520.

[0064] The imaging system 500 may also be in communication with the navigation controller 140 of the surgical navigation system 100. The imaging system 500 may be configured to communicate via a wired and / or a wireless connection with the navigation controller 140. For example, the imaging system 500 may be configured to provide pre-operative and / or intraoperative image data, such as the resulting 2-D and / or 3-D images of the surgical site 30, to the navigation controller 140. The navigation controller 140 may then be configured to display the resulting 2D and / or 3D images on the navigation display unit(s) 120. Responsive toreceiving the image data, the navigation controller 140 may also be configured to apply segmentation algorithms to the images that identifies the boundaries and types of patient tissue present in the images. Additionally or alternatively, the surgeon may interact with the patient images using the user input device(s) 130 to select and / or modify such boundaries and / or patient tissue types. The navigation controller 140 may then be configured to generate and store virtual models representative of the patient tissues of interest from the patient images based on the identified boundaries.

[0065] The surgical navigation system 100 may be configured to generate tracking data indicating the poses of patient tissue of interest in a known coordinate system by tracking patient trackers disposed relative to the patient tissue in the known coordinate system. Each patient tracker may have been previously registered to a coordinate system of a virtual model of the patient tissue to which the tracker is attached so that, by determining a pose of a patient tracker in the known coordinate system, the surgical navigation system 100 may apply the registration data to determine the pose of the virtual model in the known coordinate system. Correspondingly, the surgical navigation system 100 may determine the pose of any virtual objects associated with the patient for guiding a surgical procedure in the known coordinate system. The surgical navigation system 100 may generate tracking data indicative of the poses of the surgical instruments 220, 320, 420 in the known coordinate system in a similar manner.

[0066] More particularly, during operation of the surgical navigation system 100, the tracking unit 110, such as at the direction of the navigation controller 140, may cooperate with one or more trackers in the surgical field, such as one or more patient trackers and / or instrument trackers, to generate localization data associated with the objects to which the trackers are affixed. The localization data may indicate the detected poses of each tracker, or more particularly the detected position of each marker of each tracker, in the known coordinate system, such as a coordinate system specific to the tracking unit 110. The tracking unit 110, which may also be referred to as a localizer, may communicate the localization data to the navigation controller 140, which in turn may be configured to apply the previously stored tracker registration data to the localization data to determine the tracking data indicative of the poses of the surgical objects, or more particularly of the virtual models associated with the surgical objects, in the known coordinate system. The navigation controller 104 may thencommunicate the tracking data to and / or control other components of the surgical system 10, such as one of the instrument controllers 215, 315, 415, based on the tracking data.

[0067] Additionally or alternatively, the navigation controller 140 may be configured to determine the pose of a virtual model for patient tissue of interest in the known coordinate system based on the received patient images. In particular, patient images generated by the imaging system 500 may have a known relationship with the known coordinate system such that components of the patient images, such as pixels or voxels, may be transformed to the known coordinate system based on the known relationship. In some implementations, the imaging system 500 may be positioned relative to the tracking unit 110 according to a predefined relationship that corresponds to the known relationship. Alternatively, the imaging system 500 may include an imaging system tracker, similar to the patient and instrument trackers, the pose of which may be registered to a coordinate system of the patient images. Thus, responsive to determining a pose of the imaging tracker relative to the known coordinate system such as using the tracking unit 110 as described above, the navigation controller 140 may be configured to determine the known relationship between the coordinate system of the patient images and the known coordinate system based on a pose of the image tracker relative to the known coordinate system and the registration between the image tracker and the patient images.

[0068] As previously described, the navigation controller 140 may be configured to cooperate with other controllers of the surgical system 10, such as the instrument controllers 215, 315, 415, to control operation of the surgical instruments 220, 320, 420 as a function of the tracked poses of the surgical instruments 220, 320, 420 relative to patient tissue of interest. However, resource intensive data computations and communication between components of the surgical system 10 can create inherent latencies that if not considered may result in the surgical instruments 220, 320, 420 reaching a target state later than desired. For instance, relative to ceasing actuation of a surgical instruments 220, 320, 420 when a target depth is reached, if a controller of the surgical system 10 triggers the actuator 245, 345, 445 of a surgical instrument 220, 320, 420 to cease actuation of the end-effector 240, 340, 440 responsive to the controller receiving tracking data indicating that the surgical instrument 220, 320, 420, or more particularly the end-effector 240, 340, 440 of the surgical instrument 220, 320, 420, has already reached the target depth and / or without consideration of system latency, the surgical instrument220, 320, 420, or more particularly the end-effector 240, 340, 440 of the surgical instrument 220, 320, 420, may have already moved past the target depth by the time the actuator 245, 345, 445 and / or end-effector 240, 340, 440 ceases operation.

[0069] To thus improve control of the surgical instruments 220, 320, 420 based on their tracked poses relative to the patient tissue of interest, one or more controllers of the surgical system 10, such as the navigation controller 140 and / or one or more of the instrument controllers 215, 315, 415, may be configured to base such control of the surgical instruments 220, 320, 420 on determined mechanical inertia of the surgical instruments 220, 320, 420 and a metric of system latency. More specifically, the controller(s) may be configured to predict a future pose of each surgical instrument 220, 320, 420 relative to a virtual boundary based on a current pose of the surgical instrument 220, 320, 420 relative to the virtual boundary indicated by last received tracking data, one or more spatial movement characteristics (e.g., speed and / or trajectory) of the surgical instrument 220, 320, 420, and a system latency metric. Responsive to the future pose indicating that the surgical instrument 220, 320, 420 has reached or moved beyond the virtual boundary, the controller(s) may be configured to preemptively signal the actuator 245, 345, 445 of the surgical instrument 220, 320, 420 to cease actuation of the end-effector 240, 340, 440. In this way, the surgical instrument 220, 320, 420 is likely to cease actuation of the end-effector 240, 340, 440 before or at the virtual boundary in view of the latency and mechanical inertia of the system.

[0070] FIG. 3 illustrates a method 1000 for controlling actuation of a surgical instrument, such as one of the surgical instruments 220, 320, 420, based on the tracked pose of the surgical instrument relative to a virtual boundary and system latency. The method 1000 may be implemented by one or more of the controllers of the surgical system 10 described above.

[0071] FIG. 4 is provided as a supplement to the method 1000 of FIG. 3, and illustrates an exemplary context for the method 1000 in which a vertebra 1040 is being manipulated by the first surgical instrument 220. The description of the method 1000 below is thus provided primarily in reference to the first surgical instrument assembly 200. However, it will be appreciated that the method 1000 may additionally or alternatively be used to control operation of one or more other surgical instruments of the surgical system 10, such as the second and third surgical instruments 320, 420, in a similar manner. To this end, it will also be appreciated that references to components of the first instrument assembly 200 below may be substitutedwith that of another instrument assembly, such as the third or second instrument assemblies 300, 400, depending on the surgical instrument being controlled.

[0072] At 1002, a virtual boundary may be defined relative to patient tissue of interest, such as by the navigation controller 140. The virtual boundary may be defined in a known coordinate system in which the patient tissue of interest and surgical instrument 220 are tracked, such as a coordinate system specific to the tracking unit 110. Relative to the example of FIG. 4, a virtual boundary 1042 has been defined relative to the vertebra 1040 as a target depth for the first surgical instrument 220. At 1004, tracking data may be received, such as by the first instrument controller 215. As described above, the received tracking data may indicate a pose of the first surgical instrument 220 relative to the virtual boundary 1042. As multiple instances of tracking data are received over time, the received tracking data may define multiple “snapshots” in time of the poses of the various tracked objects, such as the poses of the first surgical instrument 220 relative to the virtual boundary 1042.

[0073] At 1006, a rate of communication of the tracking data may be determined, such as by the first instrument controller 215. For instance, the first instrument controller 215 may be configured to determine a rate in which the pose of the first surgical instrument 220 relative to the virtual boundary 1042 is updated via tracking data received by the first instrument controller 215 from the navigation controller 140.

[0074] At 1008, a system latency value associated with the tracking data, and which may be based on the communication rate of the tracking data determined above, may be compared to a threshold latency value, such as 300 milliseconds. As one example, the system latency value may be a time, such as represented in milliseconds (ms), that corresponds to a time between the first instrument controller 215 receiving tracking data indicative of a pose of the first surgical instrument 220 relative to the virtual boundary 1042 in the known coordinate system and the first instrument controller 215 receiving further tracking data indicating an updated pose of the first surgical instrument 220 relative to the virtual boundary 1042, which may correspond to the communication rate determined above. As another example, the system latency value may be a time, such as represented in milliseconds (ms), that corresponds to a time between the surgical navigation system 100, or more particularly the tracking unit 110, generating localization data indicative of a detected pose of the first tracking device 230 in the known coordinate system, and the first instrument controller 215 receiving tracking datacorresponding to the detected pose of the first tracking device 230 and that is indicative of a pose of the first surgical instrument 220 relative to the virtual boundary 1042 in the known coordinate system, which may be inferred from the determined communicate rate. The system latency value may be based on preloaded data, such as in a memory of one of the controllers 140, 215, that indicates varying system latency values as a function of the possible communication rates or times determined above. In some implementations, the system latency value may be an average, minimum, or maximum of multiple and / or repeating determinations of any of the above-described values over a time bound running window.

[0075] The latency threshold value may be a predefined value that is preprogrammed into and retrieved from a memory device of one of the controllers 140, 215. In some implementations, the controller 140, 215 may store latency threshold data indicative of varying predefined latency threshold values for varying contexts. For instance, the controller 215 may store latency data indicative of different predefined latency threshold values for different end effectors 240 that may be coupled to the handpiece 225. The first instrument controller 215 may thus be configured to determine which end effector 240 is coupled to the handpiece 225, such as based on identification data received from a memory device incorporated with the end effector 240 or based on user input received via the navigation system 100 for example, and retrieve the predefined latency threshold value corresponding thereto.

[0076] As a further example, the controller 140 may store latency data indicating different predefined latency threshold values for the different types of surgical instruments 220, 320, 420 and / or end effector 240, 340, 440 and handpiece 225, 325, 425 combinations. In this case, the controller 140 may be configured to determine which of the surgical instruments 220, 320, 420 or end effector 240, 340, 440 and handpiece 225, 325, 425 is being tracked relative to the virtual boundary, such as based on the geometry of the markers 235, 335, 435 of the detected tracker 230, 330, 430, based on a corresponding communication from one of the instrument controllers 215, 315, 415, and / or based on user input received via the user input device(s) 130, and retrieve the predefined latency threshold value corresponding thereto. In some implementations, the controller 140 may then communicate the retrieved predefined latency threshold value to the first instrument controller 215 for further processing as described herein.

[0077] For instance, step 1008 may include determining whether the system latency value is greater than or equal to the threshold latency value, such as by the first instrument controller215. Responsive to determining that the determined system latency value is greater than the threshold latency value (“No” branch of 1008), at 1010, an alert may be triggered, such as by the first instrument controller 215 or the navigation controller 140, to indicate that machine control of the first surgical instrument 220 based on tracking data generated by the surgical navigation system 100 is disabled. For instance, the first instrument controller 215 or navigation controller 140 may be configured to actuate the first alert device 255 to provide a tactile, audible, and / or visual alert. Additionally or alternatively, the first instrument controller 215 may be configured to trigger the navigation controller 140 to provide an alert on the display unit(s) 120. At this point, the surgical system 10 may disable automatic control of the actuation of the first surgical instrument 220 based on the tracked pose of the first surgical instrument 220 relative to the virtual boundary 1042. The method 1000 may then return to 1004 to continue receipt of the tracking data, and so on.

[0078] Conversely, responsive to determining that the system latency value is less than or equal to the threshold latency value (“Yes” branch of 1008), at 1012, one or more spatial movement characteristics of the first surgical instrument 220 based on the received tracking data may be determined, such as by the first instrument controller 215. The spatial movement characteristic(s) may include an average speed and trajectory (e.g., velocity) of the first surgical instrument 220 tool through the surgical workspace over a time bound running window. The spatial movement characteristic(s) may also include a lowest and highest velocity of the first surgical instrument 220 through the surgical workspace during the time bound running window.

[0079] At 1014, the first surgical instrument 220 may be controlled based on the current pose of the first surgical instrument 220 relative to the virtual boundary 1042 indicated by the tracking data, the spatial movement characteristic(s), and at least one of the determined latency value and the threshold latency value. In some implementations, the step 1014 may include calculating a look ahead factor to apply to the average velocity of the first surgical instrument 220 based on the spatial movement characteristic(s) and at least one of the determined latency value and the threshold latency value. For instance, the look ahead factor f may be calculated using the following equation:where vl and v2 are the lowest and highest velocities of the spatial movement characteristic(s) of the first surgical instrument 220 respectively; tl and t2 are estimated times, such as in milliseconds, for stopping movement of the first surgical instrument 220 through the surgical workspace when the first surgical instrument 220 is moving through the surgical workspace at the velocities vl and v2 respectively, and I is the determined system latency value, the threshold latency value, or a value calculated based on a combination of the determined system latency value and the threshold latency value (e.g., an average of the determined and threshold latency values).

[0080] The first instrument controller 215 may be configured to determine tl and t2 based on vl and v2 respectively. For instance, the first instrument controller 215 or navigation controller 140 may include preloaded data that indicates an estimated time for stopping movement of the first surgical instrument 220 through the surgical workspace as a function of velocity. In some implementations, the preloaded data may include different data sets indicating such information for each type of surgical instrument (e.g., surgical instruments 220, 320, 420) and / or end-effector 240, 340, 440 and handpiece 225, 325, 425 combination used with the surgical system 10 for determining a look ahead factor for each. Such data may be retrieved similar to as described above for the predefined latency threshold value.

[0081] A future pose of the first surgical instrument 220 relative to the virtual boundary 1042 may then be predicted based on the look ahead factor f, the current pose of the first surgical instrument 220 relative to the virtual boundary 1042 indicated by the tracking data, and the average velocity of the first surgical instrument 220. In particular, the first instrument controller 215 may be configured to apply the look ahead factor f to the average velocity of the first surgical instrument 220, such as by multiplying these two data items together, and applying the result to the current pose of the first surgical instrument 220 to determine a predicted future pose of the first surgical instrument 220.

[0082] Responsive to the predicted future pose indicating that the first surgical instrument 220 has reached or crossed the virtual boundary 1042, the first instrument controller 215 may be configured to preemptively signal the first surgical instrument 220 to cease actuation. In this way, the first surgical instrument 220 is more likely to stop at or before the virtual boundary 1042 in view of the latency and mechanical inertia of the system.

[0083] In some instances, the spatial movement characteristic(s) of the first surgical instrument 220, and correspondingly the look ahead factor f , may be determined based on additional or alternative data to the tracking data. For instance, the first instrument controller 215 may be configured to determine the spatial movement characteristic(s) of the first surgical instrument 220 based on measurements of the speed and / or direction of the actuator 245 of the first surgical instrument 220 during the time bound running window. Such measurements may be used by the first instrument controller 215 to infer an average feed rate and / or highest and lowest feed rates of the first surgical instrument 220 during the time bounded running window, such as by querying preloaded data indicative of feed rate as a function of speed and / or direction. The first instrument controller 215 may then utilize such feed rates in place of the velocities of the first surgical instrument 220 as described above.

[0084] In some implementations, the first instrument controller 215 may be configured to normalize calculation of the items discussed above such as feed rates, velocities, and / or stop times based on at least one of a torque of the actuator 245, a thread pitch of the first surgical instrument 220, and a type of implant being implanted by the first surgical instrument 220, such as using preloaded data indicative of varying normalization values associated with the same to apply to initial calculations of the items.

[0085] As described above, the surgical navigation system 100 may be configured to cooperate with a number of trackers during a surgical procedure, each being disposed relative to a different surgical object of interest to the surgical procedure. The latency of surgical object tracking provided by the surgical navigation system 100 may generally increase as the number of trackers being sensed and processed by the surgical navigation system 100 increases. Although having a complete picture of the poses of all the several tracked surgical objects may be beneficial at certain times, at other times, such as when the surgeon is focused on a particular step of a surgical procedure, it is neither needed nor desired as result of the increased tracking latency.

[0086] FIG. 5 illustrates a method 1100 for operating the surgical navigation system 100 so as to improve tracking performance during discrete steps of a surgical procedure. By the method 1100, the navigation controller 140 may be configured to detect whether a given surgical instrument, such as one of the surgical instruments 220, 320, 420, has entered a critical zone associated with a target site of patient tissue to be treated, such as based on the tracking datagenerated by the surgical navigation system 100. The critical zone may be represented in the known coordinate system by a virtual treatment zone, which in turn may be defined by one or more virtual boundaries surrounding the target site, such as a virtual bounding box. Responsive to the navigation controller 140 determining that a given surgical instrument has entered a critical zone associated with a target site of patient tissue to be treated, the navigation controller 140 may be configured to cease tracking “non-essential” trackers of the surgical system 10, such as the tracking devices 230, 330, 430 coupled to the other of the surgical instruments 220, 320, 420, in order to improve tracking performance of the “essential” trackers, that is, the trackers disposed relative to the target site and the given surgical instrument for tracking the same. Responsive to the given surgical instrument exiting the critical zone, the non-essential trackers may be added back to the tracking routine.

[0087] FIG. 6 is provided as a supplement to the method 1100 of FIG. 5, and illustrates an exemplary context for the method 1100 in which a vertebra 1140 with multiple target sites 1142, 1144 is being approached by the second surgical instrument 320. The description of the method 1100 below is thus provided primarily in reference to the second surgical instrument 320 being moved to treat the vertebra 1140. However, it will be appreciated that the method 1100 may be adapted to the context in which another surgical instrument, such as the first or third surgical instrument 220, 420, is moved towards one of the target sites 1142, 1144 for treatment of the same. To this end, it will also be appreciated that references to the second tracking device 330 below may be substituted with another tracking device, such as the first or third tracking device 230, 330, depending on the approaching surgical instrument. While FIG. 6 depicts multiple target sites 1142, 1144 relative a single vertebra 1140, it will be appreciated that the method 1100 may also be adapted and applied to a context in which multiple anatomical structures (e.g., adjacent vertebra) each having one or more target sites are being tracked by the surgical navigation system 100.

[0088] At 1102, one or more virtual treatment zones, such as defined by one or more virtual bounding boxes, may be defined relative to target site(s) of patient tissue to be treated, such as by the navigation controller 140. The one or more virtual boundary boxes may be defined in a known coordinate system in which the patient tissue of interest and surgical instrument 320 are tracked, such as a coordinate system specific to the tracking unit 110. Each virtual bounding box may generally surround a different target site, and define a virtual treatment zonerelative to the target site. Relative to the example of FIG. 6, a virtual bounding box 1146 has been defined relative to a target site 1142 of the vertebra 1140, and another virtual bounding box 1148 has been defined relative to another target site 1144 of the vertebra 1140. As shown in the illustrated example, the virtual bounding boxes 1146, 1148 may be defined relative to the target sites 1142, 1144 so as to not overlap with one another. Although FIG. 6 depicts virtual bounding boxes, the present disclosure is not limited to such example. Other types of virtual objects (e.g., a line, circle, triangle, irregular shape) may also be used to define a virtual treatment zone relative to a target site.

[0089] At 1104, the surgical navigation system 100 may be triggered, such as by the navigation controller 140, to enter a discovery mode in which new trackers are detected and registered. More specifically, the navigation controller 140 may be configured to search for new trackers that have not yet been registered with the surgical navigation system 100. In some implementations, responsive to a new tracker being activated in the surgical system 10, the navigation controller 140 may be configured to receive identifying information (e.g., serial number) from the tracker and determine, based on the identifying information, that the tracker has not yet been registered. Additionally or alternatively, the navigation controller 140 may be configured to recognize a new tracker based on unique characteristics of the tracker detected by the tracking unit 110, such as a unique marker geometry and / or transmission characteristic (e.g., frequency, light intensity, color). Responsive to determining that a new tracker has been added to the surgical field, the navigation controller 140 may be configured to prompt a user, such as via the display unit(s) 120, to identify a surgical object (e.g., instrument, patient tissue) associated with the tracker as described above.

[0090] At 1106, the surgical navigation system 100 may be triggered, such as by the navigation controller 104, to enter a tracking mode in which the previously registered trackers and the objects associated with such trackers are tracked in the known coordinate system. In other words, the navigation controller 140 may be configured to track the poses of the surgical instruments associated with registered trackers relative to patient tissue, which may likewise be associated with registered trackers, in the known coordinate system. Referring to the example of the surgical system 10 illustrated in FIG. 1 and context illustrated in FIG. 6, this may include tracking each of the surgical instruments 220, 320, 420 and the target sites 1142, 1144 of the vertebra 1140 in the known coordinate system, such as based on tracking datagenerated by the navigation controller 140 as described above. The navigation controller 140 may likewise track virtual objects, such as the virtual bounding boxes 1146, 1148, associated with the tracked patient tissue in the known coordinate system.

[0091] At 1108, a determination may be made, such as by the navigation controller 140, whether one of the surgical instruments has entered the virtual bounding box associated with a target site based on the tracking. Responsive to determining that one of the surgical instruments have not entered a virtual bounding box (“No” branch of 1108), the method may return to 1102 to trigger the discovery mode, and so on. In this way, when no surgical instrument is within a virtual bounding box, the surgical navigation system 100 may be configured to alternate between operating in the discovery mode and tracking mode, such as based on certain predefined events (e.g., switch at mode-specific regular intervals, switch to the tracking mode responsive to not discovering any new trackers for a predefined time). Alternatively, switching to the discovery mode and / or tracking mode may be based on user input instructing the same.

[0092] Responsive to determining that one of the surgical instruments has entered a virtual bounding box (“Yes” branch of 1108), at 1110, the surgical navigation system 100 may be triggered, such as by the navigation controller 140, to enter a performance mode in which the tracking of non-essential trackers is paused. That is, the navigation controller 140 may pause tracking of the trackers in the surgical field that are not associated with the one surgical instrument or the target site associated with the virtual box in which the surgical instrument has entered. Relative to the example of FIG. 6, as the tracking data would indicate the second surgical instrument 320 has entered the virtual bounding box 1146 associated with the target site 1142, the navigation controller 140 may be configured to pause tracking of the first and third tracking devices 230, 430 while continuing to track the second tracking device 330 coupled to the second surgical instrument 320. Similarly, the navigation controller 140 may pause the tracking of patient trackers not associated with the target site 1142.

[0093] In some instances, the surgical system 10 may include trackers that are in wired and / or wireless communication with the navigation controller 140, and that include active markers (e.g., LEDs) configured to selectively fire (e.g., emit light signals detectable by the tracking unit 110) at the direction of the navigation controller 140 so as to enable tracking of the same. The navigation controller 140 may pause the tracking of such trackers by ceasing to triggersuch trackers from firing. Additionally or alternatively, the surgical system 10 may include trackers with active markers that are configured to fire independently of direction from the navigation controller 140, such as for a predefined firing period that occurs at regular intervals. Such trackers may nevertheless be in wired and / or wireless communication with the navigation controller 140, and may be configured to send a communication to the navigation controller 140 to indicate when they are starting a firing period. Responsive to receiving an indication from a non-essential tracker that it is firing, the navigation controller 140 may be configured to instruct the tracking unit 110 to cease firing until a next firing period or until instructed to resume firing by the navigation controller 140, or to discard localization data generated during the firing period. Additionally or alternatively, the surgical system may include trackers with active markers that are configured to fire independently of direction from the navigation controller 140, and not inform the navigation controller 140 when they are firing, or trackers with passive markers (e.g., reflectors). In this case, responsive to the tracking unit 110 generating data indicating the poses of such trackers, the navigation controller 140 may be configured to compare the indicated poses to last known poses of the essential trackers. Responsive to determining that a distance between the indicated poses and the last known poses of the essential trackers is greater than or equal to a threshold distance, the navigation controller 140 may be configured to cease processing and discard the data as being associated with non-essential trackers.

[0094] In some implementations, responsive to determining that one of the surgical tools has entered a virtual bounding box (“Yes” branch of 1108), the navigation controller 140 may also be configured to adjust a size of the virtual bounding box. More specifically, the navigation controller 140 may be configured to increase the size of the virtual bounding box so as to avoid the surgical navigation system 100 from exiting the performance mode during a temporary retraction of the surgical instrument from the target site. Additionally or alternatively, responsive to determining that one of the surgical tools has entered a virtual bounding box, the navigation controller 140 may also be configured to operate the localizer in the tracking mode without periodically alternating between the tracking mode and the discovery mode. Responsive to performance mode being disabled as described in more detail below, the navigation controller 140 may be configured to adjust the virtual bounding box back to itsoriginal form and / or resume alternating between the discovery and tracking modes as described above.

[0095] Additionally or alternatively, in some implementations, responsive to determining that one of the surgical tools has entered a virtual bounding box (“Yes” branch of 1108), the navigation controller 140 may be configured to adjust operation of one or more of the essential trackers. For instance, some trackers disposed in the surgical field may be configured to selectively operate in a sequential firing mode in which the markers of the tracker are sequentially fired, and a parallel firing mode in which the markers of the tracker are fired at the same time. Prior to triggering of performance mode, such trackers may be operated in the sequential firing mode. Responsive to any such tracker being considered essential when the performance mode is triggered, the navigation controller 140 may be configured to instruct the tracker to switch operation to the parallel firing mode to further reduce tracking latency of the tracker. Responsive to performance mode being disabled as described in more detail below, the navigation controller 140 may be configured to instruct the tracker to switch operation back to the sequential firing mode.

[0096] At 1112, a determination may be made, such as by the navigation controller 140, of whether the surgical instrument has exited the virtual bounding box based on further tracking data. Responsive to determining that the surgical instrument has exited the virtual bounding box (“Yes” branch of 1112), at 1114, performance mode may be disabled and tracking of the poses of the previously paused trackers may be resumed. The method 1100 may then return to 1104 to trigger the discovery mode, and so on.

[0097] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the examples is described above as having certain features, any one or more of those features described with respect to any example of the disclosure can be implemented in and / or combined with features of any of the other examples, even if that combination is notexplicitly described. In other words, the described examples are not mutually exclusive, and permutations of one or more examples with one another remain within the scope of this disclosure.

[0098] In the examples and implementations described herein, the term “pose” may be replaced with “position and / or orientation”, and the term “poses” may be replaced with “positions and / or orientations”, without departing from the scope of this disclosure. Similarly, the terms “position” and “orientation” may be replaced with “pose” without departing from the scope of this disclosure.

[0099] Although the surgical system 10 is described as having multiple controllers for implementing various functions, features, and processes, it is within the scope of this disclosure for two or more of such controllers to be integrated in a single controller configured to provide the described functions, features, and processes of the separate controllers. For instance, at least one of the instrument controllers 215, 315, 415 and the navigation controller 140 may be integrated into a single controller configured to perform the functions, features, and processes of each controller. It will also be appreciated that the functions, features, and processes described above as being provided by a given controller of the surgical system 10, such as one of the instrument controllers 215, 315, 415 may, in alternative implementations, be provided by another controller of the surgical system 10, such as the navigation controller 140.

[0100] For instance, relative to the method 1000, in some implementations, the navigation controller 140 may be configured to perform one of more of 1004, 1006, 1008, 1012, and 1014. For instance, relative to the example illustrated in FIG. 4, the navigation controller 140 may be configured to determine the communication rate and / or system latency value described above as a time, such as represented in milliseconds (ms), that corresponds to a time between the navigation controller 140 determining tracking data indicative of a pose of the first surgical instrument 220 relative to the virtual boundary 1042 in the known coordinate system and the navigation controller 140 determining further tracking data indicating an updated pose of the first surgical instrument 220 relative to the virtual boundary 1042, and the time in which the navigation controller 140 receives data from the first instrument controller 215 relating to the operation of the first surgical instrument 220 and the time in which the navigation controller 140 receives further data from the first instrument controller 215 relating to further operation of the first surgical instrument 220. More particularly, the navigation controller 140 may beconfigured to determine the communication rate and / or system latency value as a sum these times. Alternatively, the navigation controller 140 may be configured to determine the communication rate and / or system latency value as a sum of the averages of these times over a time bound running window. As a further example, the navigation controller 140 may be configured to periodically ping the first instrument controller 215, and determine the communication rate and / or latency value as a time corresponding to a time between the navigation controller 140 determining tracking data indicative of a pose of the first surgical instrument 220 relative to the virtual boundary 1042 in the known coordinate system and the navigation controller 140 determining further tracking data indicating an updated pose of the first surgical instrument 220 relative to the virtual boundary 1042 and the ping reply time, such as by summing these times or summing the averages of these times as described above.

[0101] The functions, features, and processes of a given controller described herein may also be distributed across a plurality of controllers. In this application, it will be understood that one or more controllers being configured to implement a plurality of functions, features, and / or processes may include a plurality of controllers each configured to implement a different one of the functions, features, and / or processes, and that one or more controllers being configured to implement a given function, feature, or process may include a plurality of controllers that are configured to cooperate, such as via communications therebetween, to implement the given function, feature, or process.

[0102] Spatial and functional relationships between elements (for example, between controllers, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements.

[0103] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” The term subset does notnecessarily require a proper subset. In other words, a first subset of a first set may be coextensive with (equal to) the first set.

[0104] In the FIGS., the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information, but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

[0105] In this application, including the definitions below, the term “controller” or “module” may be replaced with the term “circuit.” The term “controller” may refer to, be part of, or include: at least one Application Specific Integrated Circuit (ASIC); at least one programmable system on a chip (PSoC); at least one digital, analog, or mixed analog / digital discrete circuit; at least one digital, analog, or mixed analog / digital integrated circuit; at least one combinational logic circuit; at least one field programmable gate array (FPGA); at least one processor (shared, dedicated, or group) that executes code; at least one memory circuit (shared, dedicated, or group) that stores code executed by the at least one processor; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0106] The controller may include one or more interface circuits with one or more transceivers, such as radio frequency (RF) or optical based transceivers (e.g., infrared (IR)). In some examples, the interface circuit(s) may implement wired or wireless interfaces that connect to a local area network (LAN) or a wireless personal area network (WPAN). Examples of a LAN are Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11 -2016 (also known as the WIFI wireless networking standard) and IEEE Standard 802.3-2015 (also known as the ETHERNET wired networking standard). Examples of a WPAN are the BLUETOOTH wireless networking standard from the Bluetooth Special Interest Group and IEEE Standard 802.15.4.

[0107] The controller may communicate with other controllers using the interface circuit(s). Although the controller may be depicted in the present disclosure as logically communicatingdirectly with other controllers, in various implementations the controller may actually communicate via a communications system. The communications system may include physical and / or virtual networking equipment such as hubs, switches, routers, gateways and transceivers. In some implementations, the communications system connects to or traverses a wide area network (WAN) such as the Internet. For example, the communications system may include multiple LANs connected to each other over the Internet or point-to-point leased lines using technologies including Multiprotocol Label Switching (MPLS) and virtual private networks (VPNs).

[0108] In various implementations, the functionality of the controller may be distributed among multiple controllers that are connected via the communications system. For example, multiple controllers may implement the same functionality distributed by a load balancing system. In a further example, the functionality of the controller may be split between a server (also known as remote, or cloud) controller and a client (or, user) controller.

[0109] Some or all hardware features of a controller may be defined using a language for hardware description, such as IEEE Standard 1364-2005 (commonly called “Verilog”) and IEEE Standard 1076-2008 (commonly called “VHDL”). The hardware description language may be used to manufacture and / or program a hardware circuit. In some implementations, some or all features of a controller may be defined by a language, such as IEEE 1666-2005 (commonly called “SystemC”), that encompasses both code, as described below, and hardware description.

[0110] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple controllers. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more controllers. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple controllers. The term group memory circuit encompasses a memory circuitthat, in combination with additional memories, stores some or all code from one or more controllers.

[0111] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Nonlimiting examples of a non-transitory computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0112] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks and flowchart elements described above may serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0113] The computer programs may include processor-executable instructions that are stored on at least one non-transitory computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input / output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0114] The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, JavaScript®, HTML5 (Hypertext Markup Language 5threvision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

CLAIMS1. A system for controlling operation of a powered surgical instrument as a function of tracking data latency, the system comprising: a tracker configured to be attached to the powered surgical instrument for treating patient tissue; a navigation system configured to cooperate with the tracker to generate tracking data indicative of a position of the powered surgical instrument relative to the patient tissue; and at least one controller coupled to the powered surgical instrument and configured to: determine a system latency value associated with the tracking data generated by the navigation system; determine at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data; and control an actuator of the powered surgical instrument based on the system latency value and the at least one spatial movement characteristic.

2. The system of claim 1 , wherein the at least one controller includes an instrument controller coupled to the powered surgical instrument and configured to receive the tracking data from the navigation system, and wherein the at least one controller is configured to determine the system latency value based on a communication rate of the tracking data from the navigation system to the instrument controller.

3. The system of claim 1 or 2, wherein the at least one controller is configured to: define a virtual boundary associated with the patient tissue in a known coordinate system; determine a position of the powered surgical instrument relative to the virtual boundary in the known coordinate system based on the tracking data; and control the actuator of the powered surgical instrument based on the system latency value, the at least one spatial movement characteristic, and the position of the powered surgical instrument relative to the virtual boundary in the known coordinate system.

4. The system of claim 3, wherein the virtual boundary corresponds to a target insertion depth for the powered surgical instrument relative to the patient tissue.

5. The system of any one of claims 1-4, wherein the at least one controller is configured to: compare the system latency value to a threshold latency value; and control the actuator of the powered surgical instrument based on the at least one spatial movement characteristic and at least one of the system latency value and the threshold latency value based on the comparison.

6. The system of claim 5, wherein the at least one controller is configured to: predict a future position of the powered surgical instrument relative to the patient tissue based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the at least one of the system latency value and the threshold latency value; and control the actuator of the powered surgical instrument based on the future position of the powered surgical instrument.

7. The system of claim 6, wherein the at least one spatial movement characteristic includes a first velocity and a second velocity of the powered surgical instrument through a surgical site including the patient tissue over a time bound running window.

8. The system of claim 7, wherein the first velocity and the second velocity are a highest velocity and a lowest velocity of the powered surgical instrument over the time bound running window respectively.

9. The system of claim 7 or 8, wherein the at least one controller is configured to: estimate, for each velocity of the first velocity and the second velocity, a time for stopping movement of the powered surgical instrument through the surgical site at the velocity; andpredict the future position based on the first velocity, the second velocity, the time for each of the first and second velocities, and the at least one of the system latency value and the threshold latency value.

10. The system of any one of claims 6-9, wherein the at least one controller is configured to predict the future position based on at least one of a speed of the actuator, a torque of the actuator, a thread pitch of the powered surgical instrument, and a type of implant being implanted by the powered surgical instrument.

11. The system of any one of claims 6-10, wherein the at least one spatial movement characteristic includes an average velocity of the powered surgical instrument over a time bound running window.

12. The system of claim 11, wherein the at least one controller is configured to: calculate a look ahead factor based on one or more of the at least one spatial movement characteristic and the at least one of the system latency value and the threshold latency value; and predict the future position based on the look ahead factor, the average velocity, and the current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data.

13. The system of claim 12 as far as dependent on claim 9, wherein the at least one controller is configured to calculate the look ahead factor based on the first velocity, the second velocity, the time for each of the first and second velocities, and the at least one of the system latency value and the threshold latency value.

14. The system of any one of claims 5-13, wherein the at least one controller is configured to: responsive to the comparison indicating the system latency value is less than the threshold latency value, control the actuator of the powered surgical instrument based on the at least one spatial movement characteristic and the at least one of the system latency value and the threshold latency value; andresponsive to the comparison indicating that the system latency value is greater than the threshold latency value, trigger an alert indicative that automatic control of the actuator of the powered surgical instrument is disabled.

15. The system of any one of claims 1-14, wherein the powered surgical instrument is a hand-held surgical instrument.

16. The system of any one of claims 1-15, wherein the patient tissue comprises vertebra bone tissue.

17. A system for controlling operation of a powered surgical instrument as a function of navigation data latency, the system comprising: a tracker configured to be attached to the powered surgical instrument for treating patient tissue; a navigation system configured to cooperate with the tracker to generate tracking data indicative of a position of the powered surgical instrument relative to the patient tissue; and at least one controller coupled to the powered surgical instrument and configured to: retrieve a predefined system latency value associated with the tracking data; determine at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data generated by the navigation system; and control an actuator of the powered surgical instrument based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the predefined system latency value.

18. A method for controlling operation of a powered surgical instrument for treating patient tissue as a function of navigation data latency, the method comprising: generating, by a navigation system configured to cooperate with a tracker attached to the powered surgical instrument, tracking data indicative of a position of the powered surgical instrument relative to the patient tissue;determining, by at least one controller coupled to the powered surgical instrument, a system latency value associated with the tracking data generated by the navigation system; determining, by the at least one controller, at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data; and controlling, by the at least one controller, an actuator of the powered surgical instrument based on the system latency value and the at least one spatial movement characteristic.

19. The method of claim 18, comprising: communicating the tracking data between the navigation system and an instrument controller of the at least one controller, the instrument controller coupled to the powered surgical instrument; and determining, by the at least one controller, the system latency value based on a communication rate of the tracking data from the navigation system to the instrument controller.

20. The method of claim 18 or 19, comprising: defining, by the at least one controller, a virtual boundary associated with the patient tissue in a known coordinate system; determining, by the at least one controller, a position of the powered surgical instrument relative to the virtual boundary in the known coordinate system based on the tracking data; and controlling, by the at least one controller, the actuator of the powered surgical instrument based on the system latency value, the at least one spatial movement characteristic, and the position of the powered surgical instrument relative to the virtual boundary in the known coordinate system.

21. The method of claim 20, wherein the virtual boundary corresponds to a target insertion depth for the powered surgical instrument relative to the patient tissue.

22. The method of any one of claims 18-21, comprising: comparing, by the at least one controller, the system latency value to a threshold latency value; andcontrolling, by the at least one controller, the actuator of the powered surgical instrument based on the at least one spatial movement characteristic and at least one of the system latency value and the threshold latency value based on the comparison.

23. The method of claim 22, comprising: predicting, by the at least one controller, a future position of the powered surgical instrument relative to the patient tissue based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the at least one of the system latency value and the threshold latency value; and controlling, by the at least on controller, the actuator of the powered surgical instrument based on the future position of the powered surgical instrument.

24. The method of claim 23, wherein the at least one spatial movement characteristic includes a first velocity and a second velocity of the powered surgical instrument through a surgical site including the patient tissue over a time bound running window.

25. The method of claim 24, wherein the first velocity and the second velocity are a highest velocity and a lowest velocity of the powered surgical instrument over the time bound running window respectively.

26. The method of claim 24 or 25, comprising: estimating, by the at least one controller, for each velocity of the first velocity and the second velocity, a time for stopping movement of the powered surgical instrument through the surgical site at the velocity; and predicting, by the at least one controller, the future position based on the first velocity, the second velocity, the time for each of the first and second velocities, and the at least one of the system latency value and the threshold latency value.

27. The method of any one of claims 23-26, comprising predicting the future position based on at least one of a speed of the actuator, a torque of the actuator, a thread pitch of thepowered surgical instrument, and a type of implant being implanted by the powered surgical instrument.

28. The method of any one of claims 23-27, wherein the at least one spatial movement characteristic includes an average velocity of the powered surgical instrument over a time bound running window.

29. The method of claim 28, comprising: calculating, by the at least one controller, a look ahead factor based on one or more of the at least one spatial movement characteristic and the at least one of the system latency value and the threshold latency value; and predicting, by the at least one controller, the future position based on the look ahead factor, the average velocity, and the current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data.

30. The method of claim 29 as far as dependent on claim 9, comprising calculating, by the at least one controller, the look ahead factor based on the first velocity, the second velocity, the time for each of the first and second velocities, and the at least one of the system latency value and the threshold latency value.

31. The method of any one of claims 18-30, wherein the powered surgical instrument is a hand-held surgical instrument.

32. The method of any one of claims 18-32, wherein the patient tissue comprises vertebra bone tissue.

33. A method for controlling operation of a powered surgical instrument for treating patient tissue as a function of navigation data latency, the method comprising: generating, by a navigation system configured to cooperate with a tracker attached to the powered surgical instrument, tracking data indicative of a position of the powered surgical instrument relative to the patient tissue;retrieving, by at least one controller coupled to the powered surgical instrument, a predefined system latency value associated with the tracking data; determining, by the at least one controller, at least one spatial movement characteristic of the powered surgical instrument relative to the patient tissue based on the tracking data generated by the navigation system; and controlling, by the at least one controller, an actuator of the powered surgical instrument based on the at least one spatial movement characteristic, a current position of the powered surgical instrument relative to the patient tissue indicated by the tracking data, and the predefined system latency value.

34. A system for navigating a plurality of surgical instruments relative to patient tissue including a target site to be treated during a surgical procedure, the system comprising: a first instrument tracker and a second instrument tracker configured to be attached to a first surgical instrument and a second surgical instrument respectively; a localizer configured to cooperate with the first and second instrument trackers to generate localization data indicative of a position of each of the first and second surgical instruments relative to the target site in a known coordinate system; and at least one controller coupled to the localizer and configured to: define a virtual treatment zone relative to the target site in the known coordinate system; track the position of both the first and second surgical instruments relative to the target site based on the localization data; determine whether the first surgical instrument enters the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument enters the virtual treatment zone, pause the tracking of the position of the second surgical instrument relative to the target site while continuing to track the position of the first surgical instrument relative to the target site.

35. The system of claim 34, wherein the at least one controller is configured to:while tracking the position of both the first and second surgical instruments relative to the target site based on the localization data, communicate instructions to the second instrument tracker that causes the second instrument tracker to emit light signals detectable by the localizer to generate the localization data; and pause the tracking of the position of the second surgical instrument by pausing the communication of the instructions to the second instrument tracker.

36. The system of claim 34 or 35, wherein the at least one controller is configured to: determine whether the first surgical instrument exits the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument exits the virtual treatment zone, resume the tracking of the position of the second surgical instrument relative to the target site.

37. The system of any one of claims 34-36, wherein the at least one controller is configured to, responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, adjust a size of the virtual treatment zone.

38. The system of any one of claims 34-36, wherein the at least one controller is configured to, responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, increase a size of the virtual treatment zone.

39. The system of any one of claims 34-38, wherein the first instrument tracker includes a plurality of markers configured to emit light signals detectable by the localizer to generate the localization data, the first instrument tracker being operable in a sequential marker firing mode and a parallel marker firing mode, and the at least one controller is configured to: responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, trigger the first instrument tracker to operate in the parallel marker firing mode; and responsive to determining that the first surgical instrument exits the virtual treatment zone based on the localization data, trigger the first instrument tracker to operate in the sequential marker firing mode.

40. The system of any one of claims 34-39, wherein the at least one controller is configured to: alternate operation of the localizer between a discovery mode in which new surgical instrument trackers in a view of the localizer are identified based on the localization data and a tracking mode in which one or more previously identified surgical trackers are tracked relative to the target site based on the localization data; and responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, operate the localizer in the tracking mode without alternating between the tracking mode and the discovery mode until the first surgical instrument exits the virtual treatment zone.

41. The system of any one of claims 34-40, wherein the virtual treatment zone relative to the target site is further defined as a first virtual treatment zone relative to a first target site, the patient tissue includes a second target site to be treated, and comprising: a first patient tracker and a second patient tracker configured to be attached to the patient tissue, wherein the localizer is configured to cooperate with the first and second patient trackers to generate the localization data, the localization data being indicative of a position of each of the first and second surgical instruments relative to the first and second target sites in the known coordinate system, wherein the at least one controller is configured to: define a second virtual treatment zone relative to the second target site in the known coordinate system; track the position of both the first and second surgical instruments relative to the first and second target sites based on the localization data; and responsive to determining that the first surgical instrument enters the first virtual treatment zone, pause the tracking of the position of the second surgical instrument relative to the first target site and of the position of both of the first and second surgical instruments relative to the second target site while continuing to track the position of the first surgical instrument relative to the first target site.

42. A system for navigating a surgical instrument relative to patient tissue including a plurality of target sites to be treated during a surgical procedure, the system comprising: a first patient tracker and a second patient tracker configured to be attached to the patient tissue for tracking a first target site of the patient tissue to be treated and a second target site of the patient tissue to be treated respectively; an instrument tracker configured to be attached to a surgical instrument for treating the first and second target sites; a localizer configured to cooperate with the first and second patient trackers and the instrument tracker to generate localization data indicative of a position of the surgical instrument relative to the first and second target sites in a known coordinate system; and at least one controller coupled to the localizer and configured to: define a first virtual treatment zone relative to the first target site and a second virtual treatment zone relative to the second target site in the known coordinate system; track the position of surgical instrument relative to both the first and second target sites based on the localization data; determine whether the surgical instrument enters the first virtual treatment zone based on the localization data; and responsive to determining that the surgical instrument enters the first virtual treatment zone, pause the tracking of the position of the surgical instrument relative to the second target site while continuing to track the position of the surgical instrument relative to the first target site.

43. A method for navigating a plurality of surgical instruments relative to patient tissue including a target site to be treated during a surgical procedure, the method comprising: generating, by a localizer configured to cooperate with first and second instrument trackers attached to first and second surgical instruments respectively, localization data indicative of a position of each of the first and second surgical instruments relative to the target site in a known coordinate system; and defining, by at least one controller coupled to the localizer, a virtual treatment zone relative to the target site in the known coordinate system;tracking, by the at least one controller, the position of both the first and second surgical instruments relative to the target site based on the localization data; determining, by the at least one controller, that the first surgical instrument enters the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument enters the virtual treatment zone, pausing, by the at least one controller, the tracking of the position of the second surgical instrument relative to the target site while continuing to track the position of the first surgical instrument relative to the target site.

44. The method of claim 43, comprising: while tracking the position of both the first and second surgical instruments relative to the target site based on the localization data, communicating, by the at least one controller, instructions to the second instrument tracker that causes the second instrument tracker to emit light signals detectable by the localizer to generate the localization data; and pausing, by the at least one controller, the tracking of the position of the second surgical instrument by pausing the communication of the instructions to the second instrument tracker.

45. The method of claim 43 or 44, comprising: determining, by the at least one controller, that the first surgical instrument exits the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument exits the virtual treatment zone, resuming, by the at least one controller, the tracking of the position of the second surgical instrument relative to the target site.

46. The method of any one of claims 43-45, comprising, responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, adjusting, by the at least one controller, a size of the virtual treatment zone.

47. The method of any one of claims 43-45, comprising, responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, increasing, by the at least one controller, a size of the virtual treatment zone.

48. The method of any one of claims 43-47, wherein the first instrument tracker includes a plurality of markers configured to emit light signals detectable by the localizer to generate the localization data, the first instrument tracker being operable in a sequential marker firing mode and a parallel marker firing mode, and comprising: responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, triggering, by the at least one controller, the first instrument tracker to operate in the parallel marker firing mode; determining, by the at least one controller, that the first surgical instrument exits the virtual treatment zone based on the localization data; and responsive to determining that the first surgical instrument exits the virtual treatment zone based on the localization data, triggering, by the at least one controller, the first instrument tracker to operate in the sequential marker firing mode.

49. The method of any one of claims 43-48, comprising: alternating, by the at least one controller, operation of the localizer between a discovery mode in which new surgical instrument trackers in a view of the localizer are identified based on the localization data and a tracking mode in which one or more previously identified surgical trackers are tracked relative to the target site based on the localization data; and responsive to determining that the first surgical instrument enters the virtual treatment zone based on the localization data, operating, by the at least one controller, the localizer in the tracking mode without alternating between the tracking mode and the discovery mode until the first surgical instrument exits the virtual treatment zone.

50. The method of any one of claims 43-49, wherein the virtual treatment zone relative to the target site is further defined as a first virtual treatment zone relative to a first target site, the patient tissue includes a second target site to be treated, the localizer is configured to cooperate with first and second patient trackers attached to the patient tissue for tracking the first and second target sites respectively to generate the localization data, the localization data is indicative of a position of each of the first and second surgical instruments relative to the first and second target sites in the known coordinate system, and comprising:defining, by the at least one controller, a second virtual treatment zone relative to the second target site in the known coordinate system; tracking, by the at least one controller, the position of both the first and second surgical instruments relative to the first and second target sites based on the localization data; and responsive to determining that the first surgical instrument enters the first virtual treatment zone, pausing, by the at least one controller, the tracking of the position of the second surgical instrument relative to the first target site and of the position of both of the first and second surgical instruments relative to the second target site while continuing to track the position of the first surgical instrument relative to the first target site.

51. A method for navigating a surgical instrument relative to patient tissue including a plurality of target sites to be treated during a surgical procedure, the method comprising: generating, by a localizer configured to cooperate with first and second patient trackers attached to the patient tissue for tracking a first target site of the patient tissue to be treated and a second target site of the patient tissue to be treated respectively and an instrument tracker attached to a surgical instrument for treating the first and second target sites, localization data indicative of a position of the surgical instrument relative to the first and second target sites in a known coordinate system; defining, by at least one controller coupled to the localizer, a first virtual treatment zone relative to the first target site and a second virtual treatment zone relative to the second target site in the known coordinate system; tracking, , by at least one controller, the position of surgical instruments relative to both the first and second target sites based on the localization data; determining, , by at least one controller, that the surgical instrument enters the first virtual treatment zone based on the localization data; and responsive to determining that the surgical instrument enters the first virtual treatment zone, pausing, by at least one controller, the tracking of the position of the surgical instrument relative to the second target site while continuing to track the position of the surgical instrument relative to the first target site.

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