An alert system that operates based on location-specific recognition

Abstract

A handheld surgical system comprises an instrument configured to be held in a user's hand and including a drive motor. The instrument is coupled to a tracking device. The handheld surgical system also comprises a tracking unit, an alert module, and a control system, the control system communicating with the tracking unit, the alert module, and the instrument. The control system is configured to track the pose of the instrument in a known coordinate system using the tracking unit, determine a boundary associated with a region of interest of a surgical procedure in the known coordinate system, control the alert module based on the boundary and the tracked pose of the instrument, determine that a occlusion event has occurred at the tracking device, and control the drive motor based on the occlusion event, the boundary, and the tracked pose of the instrument.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 346,075, filed on May 26, 2022, and U.S. Provisional Patent Application No. 63 / 350,224, filed on Jun. 8, 2022, the disclosures of each of which are hereby incorporated by reference in their entirety.

Background Art

[0002] In modern surgery, medical practitioners frequently use powered surgical instruments such as cordless drills, saws, wire drivers, high - speed drills, ultrasonic handpieces, etc. Many of these surgical instruments incorporate a drive motor and / or a processor within a handpiece or housing. The surgical instrument is provided with a mounting mechanism configured to receive a cutting attachment designed to be applied to a surgical site for performing a specific medical procedure. For example, a surgical drill may use cutting attachments such as drill bits, burs, reamers, etc. to create holes in tissue or selectively remove tissue such as bone. If powered surgical instruments can be used on patients, the physical burden on the surgeon during a medical procedure on the patient is alleviated. More specifically, using powered surgical instruments can generally perform most surgical procedures more quickly and accurately than their manually - operated equivalents that have been used previously.

[0003] To further enhance the accuracy and effectiveness of surgical procedures that require powered surgical instruments, these instruments are often tracked by a positioning system. These positioning systems can alert the surgeon if the powered surgical instrument deviates from the course or approaches an important structure such as the spinal cord. These positioning systems often rely on a line-of-sight with the surgical instrument. Depending on the surgery performed by the surgeon, the line-of-sight between the positioning system and the surgical instrument may frequently be blocked. Such blockages may occur particularly frequently when the surgical instrument is a hand-held instrument that the surgeon can move to various positions.

[0004] While alerts in response to the loss of line-of-sight may be useful to the surgeon in some cases, they may not be in others, such as when the loss is insignificant and / or not important. Such alerts in the latter case may be annoying or confusing to the surgeon. Further, if the system is configured to stop the operation of the surgical tool, the surgeon may be prone to a situation where the tool being used is frequently deactivated in response to an insignificant and / or not important loss of line-of-sight.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, in the art, there is a need for surgical systems and methods that can determine and distinguish whether the loss of line-of-sight is relatively important or not important in order to reduce the number of alerts and interruptions during surgery.

Means for Solving the Problems

[0006] According to a first aspect, a handheld surgical system is provided. The system includes an instrument configured to be held in a user's hand and including a drive motor, a console coupled to the instrument, a tracking device coupled to the instrument, a tracking unit, an alert module, and a control system that communicates with the tracking unit, the alert module, and the console. The control system is configured to determine the posture of the instrument, determine a boundary, control the alert module based on the boundary and the posture of the instrument, determine that a shielding event has occurred in the tracking device, and control the drive motor based on the shielding event, the boundary, and the posture of the instrument.

[0007] According to a second aspect, a handheld surgical system is provided. The system includes an instrument configured to be held in a user's hand and including a drive motor, a tracking device coupled to the instrument, a tracking unit, an alert module, and a control system that communicates with the tracking unit and the alert module. The control system is configured to determine the posture of the instrument, determine a boundary, control the alert module based on the boundary and the posture of the instrument, determine that a shielding event has occurred in the tracking device, determine the duration of the shielding event, determine the distance between the instrument and the boundary, and control the drive motor based on the shielding event, the duration of the shielding event, the boundary, the posture of the instrument, and the distance between the instrument and the boundary.

[0008] Any of the above aspects can be combined, in part or in whole, with any other aspect. Regardless of whether any of the above aspects are combined in part or in whole, they can further be combined, in part or in whole, with any of the following embodiments.

[0009] In some embodiments, the control system is further configured to determine at least one of the duration of the shielding event, the duration threshold, the boundary, the distance between the appliance and the boundary based on the posture of the appliance, the direction of movement of the appliance based on the posture of the appliance and the boundary, the speed of the appliance based on the boundary and the posture of the appliance, and the motion parameters of the appliance based on the posture of the appliance and the boundary. In some embodiments, the motion parameters are selected from at least one of the direction of the appliance, the speed of the appliance, the velocity of the appliance, and the acceleration of the appliance.

[0010] In some embodiments, the control system is further configured to control the drive motor based on at least one of the duration of the shielding event, the distance and the shielding event, the duration and the distance and the shielding event, the duration and the duration threshold, the direction of movement of the appliance and the shielding event, and the speed of the appliance.

[0011] In some embodiments, the control system is further configured to determine a first posture of the appliance based on the posture of the appliance at a first point in time and a second posture of the appliance based on the posture of the appliance at a second point in time. In some embodiments, the control system is further configured to determine the direction of the appliance based on the first posture and the second posture of the appliance and / or determine the speed of the appliance based on the first posture and the second posture of the appliance.

[0012] In some embodiments, the system further comprises a location recognition indicator that communicates with the control system. In some embodiments, the control system controls the location recognition indicator based on the shielding event. In some embodiments, the location recognition indicator is defined as at least one of an auditory indicator, a visual indicator, and a tactile indicator. In some embodiments, the location recognition indicator is defined as a software routine.

[0013] In some embodiments, the alert module is at least one of a vibratory foot switch, a graphical user interface, a speaker, and a software routine. In some embodiments, the software routine is configured to set the driving speed of the motor and / or to stop the driving motor.

[0014] In some embodiments, the system further comprises a switch that communicates with the instrument and the control system, and the switch is configured to generate an input signal sufficient to control the instrument. In some embodiments, the control system is further configured to restart the driving motor based on the input signal.

[0015] In some embodiments, the instrument further comprises a battery that electrically communicates with the driving motor, and the control of the driving motor includes the control of the battery.

[0016] In some embodiments, the boundary is a mesh. In some embodiments, this mesh is obtained from at least one of a patient image and a segmentation of the patient image.

[0017] In some embodiments, the system further comprises a patient tracking device attached to the patient, and the control system is further configured to determine at least a partial posture of the patient and to determine that a shielding event has occurred in the patient tracking device.

[0018] These configurations, features, and advantages of the present disclosure, as well as other configurations, features, and advantages, should be apparent to those skilled in the art. The present disclosure is not intended to be limited to these configurations, embodiments, features, and / or advantages.

[0019] The advantages of the present invention will be more readily understood by referring to the following detailed description when considered in connection with the accompanying drawings.

Brief Description of the Drawings

[0020]

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DETAILED DESCRIPTION OF THE INVENTION

[0021] In today's surgery, tracking information is used to confirm whether a surgical instrument is following a planned surgical path and / or maintaining a safe distance from important anatomical structures, and accordingly, when the surgical instrument deviates from the surgical path and / or there is a risk of hitting an important anatomical structure, provide feedback to and / or notify the medical staff performing the surgery. For this purpose, it is also beneficial to provide feedback to and / or notify the medical staff when the tracking becomes so unreliable that the tracking information cannot determine whether the surgical instrument is following the planned surgical path and / or maintaining a safe distance from important anatomical structures.

[0022] Accordingly, FIG. 1 shows an exemplary surgical system 10, which includes a surgical navigation system 100 that tracks one or more surgical instrument assemblies 200, 300, 400 each including surgical instruments 220, 320, 420, and can assist medical staff such as surgeons when performing medical procedures.

[0023] The surgical navigation system 100 can include a navigation interface including one or more display units 120 and one or more user input devices 130, and this device may be implemented as a touch screen mechanism integrated with the display unit 120. The display unit 120 of the surgical navigation system 100 can be configured to display one or more graphical user interfaces (GUIs) 150, and this GUI may include various prompts or data input boxes for receiving input from the user. For example, the display unit 120 can be configured to display a text box or prompt that allows a surgeon to manually enter or select the type of surgical procedure to be performed. The display unit 120 may also be configured to display patient data such as preoperative images or scans. The preoperative image may be based on an MRI scan, a radiation scan, or a computed tomography (CT) scan of the patient's anatomical structure. The preoperative image may be uploaded to the surgical navigation system 100 and displayed on the display unit 120. The display unit 120 may further be configured to display a surgical plan for a medical treatment by overlaying it on the patient data or image.

[0024] The surgical plan can include a surgical path for performing a medical procedure, and / or a planned trajectory, and / or the orientation of a medical instrument during the medical procedure. The surgical plan can also include the position and / or orientation of an implant or medical device inserted into the region of interest during the medical procedure, overlaid on patient data or an image. It is contemplated that the surgical navigation system 100 can include a display unit 120 configured to display and / or project a holographic image of a surgical path for performing a medical procedure, and / or a planned trajectory, and / or the orientation of a medical instrument during the medical procedure. This can include projecting the surgical path onto the patient or onto another wall surface of the operating room. It can also include projecting the surgical path onto a head unit worn by the surgeon, such as the 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 and displaying the target trajectory and / or target position of the medical procedure is disclosed in International Patent Application No. PCT / IB2018 / 053130, the entire disclosure of which is incorporated herein by reference in its entirety.

[0025] The user input device(s) 130, and / or the graphical user interface (GUI) 150, can be configured such that a surgeon can input or enter patient data and / or modify a surgical plan. The patient data may include patient images such as preoperative images of the patient's anatomical structure. Such images may be based on an MRI scan, a radiation scan, or a computed tomography (CT) scan of the patient's anatomical structure. The patient data may also include additional information related to the type of medical treatment to be performed, the patient's anatomical shape parts, the patient's specific medical conditions, and / or the operation settings of the surgical navigation settings. For example, when performing spinal surgery, the surgeon can enter information related to the specific vertebrae where the medical treatment is being performed via the user input device(s) 130, and / or the graphical user interface (GUI) 150. The surgeon can also input various anatomical dimensions related to the vertebrae and / or the size and shape of the medical device or implant to be inserted during the medical treatment. Further, the user input device(s) 130, and / or the graphical user interface (GUI) 150, can be configured such that a surgeon can select, edit, or manipulate patient data. For example, the surgeon can identify and / or select from the patient data the anatomical shape parts that define the region of interest of the medical treatment. This may include selecting one or more surgical sites where the medical treatment is to be performed, for example, selecting one or more vertebrae and / or specific regions of one or more vertebrae.

[0026] The surgeon can also identify important anatomical features that define the region of interest for a medical procedure, such as anatomical features that the surgeon may want to target or avoid during the medical procedure. For example, the surgeon can use the user input device(s) 130 and / or the graphical user interface (GUI) 150 to select a cortical wall or a part thereof, a nerve, a blood vessel, or a similar important anatomical structure that the surgeon believes should be avoided, and establish a zone surrounding these anatomical structures. The surgeon can also use the user input device(s) 130 and / or the graphical user interface (GUI) 150 to select and / or input the target position of the surgical path, the target region to be resected, the target trajectory, the target depth, or similar features, and these features are associated with the region of interest to help guide the surgeon during the medical procedure.

[0027] The system can be configured to utilize segmentation to facilitate the identification of zones and / or boundaries associated with the region of interest for a medical procedure. This segmentation can be performed automatically, semi-automatically, or manually.

[0028] In an example of manual segmentation, a surgeon can define geometric primitives associated with regions of interest of a medical procedure using a user input device(s) 130 and / or a graphical user interface (GUI) 150. Methods of defining geometric primitives for the segmentation and visualization of body cavities or openings can include, as the following steps, manually pre-segmenting by defining closed geometric primitives and generating an initial envelope within a three-dimensional patient image, analyzing anatomical structures within the geometric primitives after pre-segmentation, adjusting the envelope using the analysis results, and visualizing the envelope. Adjustment of the visualized envelope can be based on anatomical structures analyzed using calculated voxel associations, and adjustment of the visualized cell envelope can be achieved, in whole or in part, by calculating a surface mesh of the voxels associated with the cell. Further, adjustment of the visualized envelope can be achieved by optimizing the type, orientation, position, and / or size of the closed geometric primitive. Exemplary methods and systems for defining geometric primitives and guiding surgical instruments are disclosed in U.S. Patent Application No. 15 / 300,414 and U.S. Patent Application No. 15 / 582,637, the entireties of both of which are incorporated herein by reference in their entireties.

[0029] Further, the user input device(s) 130 and / or the graphical user interface (GUI) 150 can be configured to enable input for surgical planning. This can include selection of surgical instruments to be used, devices to be inserted, and / or implants to be selected. This can further include specifying, as regions of interest, the location and / or orientation (i.e., pose) at which a device or implant is to be placed within the patient. Also, the user input device(s) 130 and / or the graphical user interface (GUI) 150 enable a surgeon to select parameters of an implant to be inserted, such as the length and / or diameter of a screw to be inserted.

[0030] The surgical navigation system 100 can further include a navigation processor 140. The navigation processor 140 can be disposed in a personal computer or a laptop computer. The navigation processor 140 can communicate with a user input device(s) 130, a display unit(s) 120, a central processing unit (CPU) and / or other processors (e.g., the respective instrument processors 215, 315, 415 of the instrument assemblies 200, 300, 400), a memory (not shown), and a storage device (not shown). The navigation processor 140 further includes software and / or operating instructions related to the operation of the surgical navigation system 100 and can be configured to implement various routines and / or methods disclosed herein when executed. For example, the software and / or operating instructions can include a planning system configured to determine the precise position and / or angle adjustment of the implant with respect to the patient 20 (FIG. 2). The navigation processor 140 can communicate directly or indirectly, wired or wirelessly, with the surgical instrument assemblies 200, 300, 400.

[0031] The surgical navigation system 100 can further include software utilized by the navigation processor 140 to control the operation of the surgical assemblies 200, 300, 400, or more specifically, the surgical instruments 220, 320, 420. The software can include a boundary generation unit. The boundary generation unit can be implemented in one or more of the navigation processor 140, the instrument processors 215, 315, 415, and / or other components, such as a separate processor or controller. Exemplary systems and methods for boundary generation are described in U.S. Patent Publication No. 2004 / 0034283A1, which is hereby incorporated by reference in its entirety. The boundary generation unit can also be part of a separate system that operates remotely from the surgical system 10. The boundary generation unit is a software program or module that generates one or more virtual boundaries and / or one or more alert zones to constrain the movement and / or operation of the surgical instruments 220, 320, 420. The virtual boundaries and / or zones can be associated with one or more regions of interest of a medical procedure, such regions including, but not limited to, anatomical shapes or regions that are the target of a procedure, resection, or surgical implant reception, and / or anatomical shapes or regions to be avoided. In some examples, the boundary generation unit provides a virtual boundary that defines a guide for a virtual drill and / or driver (e.g., a virtual implant planning guide). The virtual boundary or alert zone can also be provided to control the operation of the surgical instruments 220, 320, 420 based on important anatomical shapes, target depths, target regions to be resected, and / or target positions that the surgeon wishes to avoid or treat. The virtual boundary can be one-dimensional (1D), two-dimensional (2D), or three-dimensional (3D), and can include other shapes such as points, lines, axes, trajectories, planes (infinite planes or planar portions bounded by anatomical structures or other boundaries), volumes, or complex geometric shapes. The virtual boundary can be represented by pixels, point clouds, voxels, triangle meshes, other 2D or 3D models, and combinations thereof, etc.U.S. Patent Publication No. 2018 / 0333207 and U.S. Patent No. 8,898,043 are hereby incorporated by reference in their entirety and any of these features may be used to facilitate the planning or execution of a surgical procedure. A plurality of boundaries may likewise be used to define zones associated with one or more regions of interest.

[0032] Virtual boundaries can be used in a variety of ways. For example, the navigation processor 140 can control certain operations / functions of the surgical instruments 220, 320, 420 based on the relationship (e.g., space, velocity, etc.) of the surgical instruments 220, 320, 420 to the boundaries and / or zones. Other uses of the boundaries and / or zones are also contemplated.

[0033] A boundary for ensuring that an instrument is positioned at a desired depth can be defined by a virtual plane boundary, a virtual volume boundary, or other forms of virtual boundaries. Virtual boundaries may also be referred to as virtual objects. Virtual boundaries can be defined with respect to an anatomical model such as a 3D bone model. That is, the points, lines, axes, trajectories, surfaces, volumes, etc. associated with the virtual boundary are defined in a coordinate system that is fixed with respect to the coordinate system of the anatomical model so that when the anatomical model is tracked (e.g., via tracking of the associated aligned anatomical structures), the virtual boundary can also be tracked.

[0034] The anatomical model can be aligned with the patient tracking device PT so that the virtual boundary is associated with the anatomical model and the associated coordinate system. The virtual boundary can be implant-specific, e.g., defined based on the size, shape, volume, etc. of the implant, and / or patient-specific, e.g., defined based on the patient's anatomical structure. The virtual boundary can be a boundary created preoperatively, intraoperatively, or a combination of these. That is, the virtual boundary can be defined before the start of the surgical procedure, during the surgical procedure (including during tissue removal), or a combination of these. The virtual boundary can be provided in many ways, such as created by the navigation processor 140 or received from other information sources / systems. The virtual boundary can be stored in memory for retrieval and / or update.

[0035] Furthermore, in some cases, it is also contemplated that the virtual boundary can have multiple planar boundaries that can be used to indicate multiple target depths (e.g., three target depths) for separate instruments to be used in a single surgery. For example, the multiple virtual boundaries can include a first virtual boundary representing a target depth for drilling a hole in the region of interest, a second virtual boundary representing a target depth of a tap with respect to the region of interest, and a third virtual boundary representing a target depth for inserting a screw with a driver with respect to the region of interest. These are shown in FIG. 5 and will be described in more detail below. These multiple virtual boundaries can be activated one by one by the navigation processor 140 and can be restricted to cut one plane at a time. The navigation processor 140 can track the states of the surgical instruments 220, 320, 420 with respect to the virtual boundary.

[0036] The surgical navigation system 100 can also include a tracking unit 110. The tracking unit 110 cooperates with the tracking devices 230, 330, 430 of the surgical instrument assemblies 200, 300, 400 and / or the patient tracking device PT (FIG. 2) to generate tracking data indicating the posture of the surgical instruments 220, 320, 420 of the surgical instrument assemblies 200, 300, 400 and / or the posture of the patient, more specifically, one or more regions of interest of the patient, in a known coordinate system, for example, a coordinate system specific to the tracking unit 110. For this purpose, the tracking unit 110 can include one or more sensors 115. Examples of the sensor(s) 115 include 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 and / or orientation (posture) of the tracking devices 230, 330, 430 of the surgical instrument assemblies 200, 300, 400 in a known coordinate system. Next, the navigation processor 140 is configured to apply a conversion function to such positions and / or orientations based on the known relationship between the tracking devices 230, 330, 430 and the surgical instruments 220, 320, 420 in a known coordinate system to determine the position and / or orientation of the surgical instruments 220, 320, 420 in the known coordinate system. Tracking the position and / or orientation of the region of interest of the patient can be performed similarly using one or more patient tracking devices PT arranged based on that region. A description of a suitable tracking unit 110 and the various positioning devices available therein is described in U.S. Patent Publication No. 2017 / 0333137, the entire disclosure of which is incorporated herein by reference.

[0037] Referring to FIG. 1, various exemplary surgical instrument assemblies 200, 300, 400 are illustrated as being in communication with a surgical navigation system 100. Each of the various exemplary surgical instrument assemblies will be described in detail below. The surgical instrument assemblies 200, 300, 400 can be configured to communicate with the surgical navigation system 100 in a wired and / or wireless manner. Further, each of the surgical instrument assemblies 200, 300, 400 includes a number of similar components that can perform similar functions and / or operations. Similar components among the various surgical instrument assemblies 200, 300, 400 are designated with the same two-digit number preceded by 2, 3, 4 to represent the associated surgical instrument assemblies 200, 300, 400. For example, the surgical instrument assemblies 200, 300, 400 can each include a surgical instrument 220, 320, 420.

[0038] The surgical system 10 can include a first surgical instrument assembly 200 that communicates with the navigation system 100. For example, the first surgical instrument assembly 200 may be implemented as a first surgical instrument 220, such as a surgical drill or driver, that includes a handpiece 225. The handpiece 225 can have a housing 210 configured to house components of the first surgical instrument 220. The handpiece 225 can be shaped to define a handle or grip portion for a surgeon to grasp during the performance of a medical procedure. A suitable handpiece is described in U.S. Patent No. 5,747,953, which is hereby incorporated by reference in its entirety.

[0039] The first surgical instrument 220 can further include a first instrument processor 215 and a drive motor 245. The first instrument processor 215 and the drive motor 245 can each be disposed within the handpiece 225 of the first surgical instrument 220. The first instrument processor 215 and the drive motor 245 can communicate with each other, and the first instrument processor 215 can be configured to control the operation of the drive motor 245, and thus the operation of the first surgical instrument 220. For example, the first surgical instrument 220 can have an end effector 240 such as a drill bit for making a hole or a driver for inserting a screw into the region of interest. The end effector 240 can be coupled to the handpiece 225 of the first surgical instrument 220 such that the drive motor 245 can be operably coupled to the end effector 240. For example, the drive motor 245 can be configured to rotate the drill bit 240 to make a hole and / or remove biological tissue from the region of interest. The first instrument processor 215 can communicate with the drive motor 245 and can be configured to control the operation of the drive motor 245, and thus the drill bit 240. Further, the first instrument processor 215 can communicate with the navigation processor 140 and can be configured to exchange data related to the position and / or orientation of the first surgical instrument 220, as well as data related to the operation of the first surgical instrument 220. For example, the first instrument processor 215 and the navigation processor 140 can be configured to communicate with each other data related to the operation of the first surgical instrument 220 based on the position and / or orientation of the first surgical instrument 220 detected by the surgical navigation system 100.

[0040] The first surgical instrument assembly 200 can also have a power source 260. The power source 260 can be detachably coupled to the handpiece 225 of the first surgical instrument 220. For example, the power source 260 can have a detachable battery pack. It is also contemplated that the power source 260 can be formed as a part of or disposed within the handpiece 225 of the first surgical instrument 220. The power source 260 can be configured to selectively supply power to the drive motor 245 to rotate the end effector 240 by electrically communicating with the first instrument processor 215 and / or the drive motor 245. Also, the power source 260 can be a surgical console that supplies power to the first surgical instrument 220 via a cord.

[0041] When the power source 260 is in the form of a detachable battery pack, the power source 260 can further have a processor 265. The processor 265 can communicate with the first instrument processor 215 via a power signal and / or a data signal. The processor 265 and the first instrument processor 215 can be configured to communicate with each other to control the operation of the drive motor 245 and, thus, the operation of the first surgical instrument 220. For example, the processor 265 within the power source 260 can be configured to identify when the power source 260 falls below a threshold charge level at which the power source 260 can no longer continue to operate the drive motor 245 at a minimum threshold for making holes or cutting biological tissue. The processor 265 can be configured to completely cut off power to the first instrument processor 215 and / or the drive motor 245 to prevent the operation of the end effector 240 until the power source 260 obtains a charge level sufficient to operate the drive motor 245 at a speed exceeding the minimum threshold for making holes or cutting biological tissue. Also, the processor 265 within the power source 260 can be wirelessly communicable with the navigation processor 140. For this purpose, the power source 260 can include a transceiver configured to transmit and receive signals between the power source 260 and the surgical navigation system 100 and / or the instrument processor 215.

[0042] Processor 265 and navigation processor 140 can be configured to communicate with each other data related to the operation of the first surgical instrument 220 based on the position and / or orientation of the first surgical instrument 220 detected by the surgical navigation system 100. For example, the navigation system 100 can be configured to communicate to processor 265 data including an instruction for processor 265 to stop supplying energy to the first instrument processor 215 and / or drive motor 245 based on the position and / or orientation of the first surgical instrument 220 detected by the surgical navigation system 100. Further, the navigation system 100 can be configured to communicate to processor 265 data including an instruction for processor 265 to continue and / or resume supplying energy to the first instrument processor 215 and / or drive motor 245 based on the position and / or orientation of the first surgical instrument 220 detected by the surgical navigation system 100.

[0043] The first surgical instrument assembly 200 can also have a switch 250, such as a trigger or a button or a lever, which is operably coupled to the first instrument processor 215. The switch 250 can be configured to be operable by a medical professional to control the energization of the variable speed drive motor 245. For example, the switch 250 can be operable between a first position in a non-energized state and a second position in an energized state. Further, the first surgical instrument assembly 200 can have a switch sensor configured to detect the position of the switch 250 and generate a signal indicating the position of the switch 250 based on a user's operation of the switch 250 to control the operation of the first surgical instrument 220, and / or communicate this signal to the first instrument processor 215. For example, the switch 250 can include a first position, a second position, and a plurality of intermediate positions between the first position and the second position. The first position can be configured as an off position such that when the first instrument processor 215 receives a signal from the switch sensor detecting that the switch 250 is in the first position, the first instrument processor 215 blocks the flow of energy from the power source 260 to the drive motor 245 to prevent the operation of the first surgical instrument 220. Conversely, the second position and the plurality of intermediate positions can each be configured as an on position. When the first instrument processor 215 receives a signal from the switch sensor detecting that the switch 250 is in the second position, the first instrument processor 215 can be configured to allow the maximum flow of energy from the power source 260 to the drive motor 245 so that the first surgical instrument 220 can operate at the maximum drilling speed or cutting speed. When the first instrument processor 215 receives a signal from the switch sensor detecting that the switch 250 is in one of the intermediate positions, the first instrument processor 215 can be configured to allow a level of energy corresponding to the position of the switch 250 between the first position and the second position to flow from the power source 260 to the drive motor 245 so that the first surgical instrument 220 can operate at an intermediate level of drilling speed or cutting speed.For example, when the first instrument processor 215 receives a signal detected by a switch sensor that the switch 250 is positioned halfway (50%) between the first position and the second position, the first instrument processor 215 can be configured to allow energy at a level that enables the first surgical instrument 220 to operate at 50% of the maximum drilling speed or drive speed to flow from the power source 260 to the drive motor 245. Alternatively, when the switch 250 is in a position other than the first position, the first instrument processor 215 can be configured to always allow the maximum flow of energy from the power source 260 to the drive motor 245, so that when the switch 250 is in either the second position or an intermediate position, the first surgical instrument 220 can operate at the maximum drilling or cutting speed. An exemplary switch sensor is described in U.S. Patent No. 9,295,476, which is hereby incorporated by reference in its entirety.

[0044] The first surgical instrument assembly 200 can also include a first alert module 255. The first alert module 255 can be configured to indicate the position of the first surgical instrument 220 based on regions of interest in a surgical procedure, such as tissue regions to be avoided, tissue regions to be treated, tissue regions to be excised, or regions for receiving a surgical implant. More specifically, the first alert module 255 can be configured to indicate when the end effectors 240 of the first surgical instruments 220, 320, 420 enter or cross a pre-determined distance from a boundary associated with the region of interest. To that end, the first alert module 255 can include devices that are perceptible audibly, tactually, and / or visually. The first alert module 255 can alternatively be a software routine. The first alert module 255 can be configured to communicate with the first instrument processor 215 or the processor 265 of the power supply 260. The first instrument processor 215, the processor 265, or another processor of the surgical system 10 (e.g., the navigation processor 140) can be configured to send a signal to activate the first alert module 255 to provide a warning or notification based on pre-programmed conditions or settings.

[0045] For example, as described above, the surgeon can use the user input device(s) 130 to select cortical walls, nerves, blood vessels, or similar important anatomical structures that the surgeon wishes to avoid, and input predetermined conditions and / or settings, such as for establishing regions or zones (e.g., zones to be excluded from cutting) surrounding these anatomical structures, into the surgical navigation system 100. Further, the surgeon can use the user input device(s) 130 to select and / or input a target position (location(s)), a target region for resection, a target trajectory in one or more degrees of freedom, or a similar shaped portion of a surgical path to assist in guiding the surgeon during the performance of a medical procedure. The first instrument processor 215 can be configured to send a signal to activate the first alert module 255 when the end effector 240 of the first surgical instrument 220 enters one of the regions and / or zones defined by the surgeon, based on data provided by the navigation processor 140. The first instrument processor 215 or another processor can also be configured to send a signal to activate the first alert module 255 when the end effector 240 of the first surgical instrument 220 deviates from a trajectory and / or when the end effector 240 reaches a target position / region, based on data provided by the navigation processor 140.

[0046] In an exemplary configuration, the first alert module 255 can have a vibration device configured to contact the surgeon and vibrate to notify the surgeon of a specific state or give a warning. In an exemplary configuration, as shown in FIG. 1, the first alert module 255 can include a vibration device coupled to a switch 250 that controls the operation of the first surgical instrument 220. The first alert module 255 can be configured to vibrate when a predetermined state occurs. When driving the first surgical instrument 220, the surgeon will always be in contact with the switch 250, so the surgeon should feel the first alert module 255 vibrating and be notified of the occurrence of the predetermined state. The first alert module 255 can be configured to generate vibrations in a specific pattern or at specific intervals when a predetermined state occurs. Alternatively, the first alert module 255 can be configured to generate a first vibration in a specific pattern or at specific intervals when a first state occurs, and generate a second vibration in a different pattern or at different intervals when a second state occurs.

[0047] The first alert module 255 can further be configured as an audible device, such as a speaker, configured to supply an audible alert to the surgeon when a predetermined state occurs. For example, the first alert module 255 can have a speaker configured to generate a specific sound when a predetermined state occurs. Alternatively, the first alert module 255 can have a speaker configured to generate sound in a specific pattern or at specific intervals when a predetermined state occurs. The speaker can be part of the surgical navigation system 100.

[0048] As yet another configuration, the first alert module 255 can be configured as a visually recognizable device or indicator, such as a visual display, configured to supply a visual alert to the surgeon upon the occurrence of a predetermined state. For example, the first alert module 255 can have illumination configured to blink upon the occurrence of a predetermined state. Alternatively, the first alert module 255 can have a plurality of multi-color illuminations configured to illuminate and / or blink in a predetermined color or pattern upon the occurrence of a predetermined state. When the first alert module 255 is a display, the display can be configured to generate a visual cue indicating the alert state. The navigation display unit 120 can be used as the display for the first alert module 255 such that the navigation display unit 120 is configured to provide a visual cue for warning the surgeon. For example, the navigation display unit 120 can be configured such that when the first alert module 255 is triggered, a prompt or window is displayed to supply a notification to the surgeon. Alternatively, the navigation display unit 120 can be configured to blink and / or change color when the first alert module 255 is triggered. One of the many advantages of using the navigation display unit 120 as the display of the first alert module 255 is that since the surgeon is already likely to be regularly looking at the navigation display unit 120 during the surgery, if the navigation display unit 120 is configured to display the notifications supplied from the first alert module 255, the surgeon is more likely to quickly receive the visual notification.

[0049] The detachable power source 260 can further have the first alert module 255 in a certain specific configuration. For example, the detachable power source 260 can include a vibration motor or a speaker responsive to a signal generated by the navigation processor 140.

[0050] Furthermore, it is also contemplated that the first alert module 255 can have a combination of audible, tactile, and / or visually perceptible devices. For example, the first alert module 255 can be configured as a combination of an audible device and a tactile device. In this case, the tactile device can be configured to vibrate to provide a first alert, and the audible device can be configured to generate noise to provide a second alert. The first alert and the second alert may indicate the occurrence of the same predetermined state, or alternatively, the first alert and the second alert may indicate the occurrence of different predetermined states. For example, the first alert can be based on the fact that the first surgical instrument 220 has deviated from the target trajectory, and the second alert can be based on the fact that the end effector 240 has reached the target position.

[0051] Furthermore, it is contemplated that the first alert module 255 can be configured as a software routine configured to control audible, tactile, and / or visually perceptible devices. The software routine can also be configured to control a combination of audible, tactile, and / or visually perceptible devices. For example, the software routine can include instructions stored in a memory accessible by the surgical navigation system 100, one or more of the surgical instrument assemblies 200, 300, 400, and / or other elements of the surgical system 10.

[0052] The first alert module 255 is shown coupled to or in proximity to the switch 250 of the first surgical instrument assembly 200, although it is contemplated that the first alert module 255 may be coupled and / or positioned at other locations. For example, if the first alert module 255 includes a tactile device, the first alert module 255 may be configured as a vibrating member removably attached to the surgeon. The first alert module 255 may be configured as a wearable device, such as a bracelet worn on the surgeon's wrist or arm, so that the surgeon can feel the first alert module 255 vibrate when a predetermined condition occurs. Alternatively, if the first alert module 255 includes an audible device, the first alert module 255 may be configured as a speaker removably attached to the surgeon. The first alert module 255 may be configured as a Bluetooth®-compatible speaker or earpiece to be worn on the surgeon's head or positioned within the surgeon's ear so that the surgeon can hear the noise emitted by the first alert module 255 when a predetermined condition occurs.

[0053] Although not necessary, positioning the first alert module 255 away from the first surgical instrument 220 has many advantages. For example, one advantage of positioning the first alert module 255 away from the first surgical instrument 220 is that the size of the first surgical instrument 220 can be reduced. This allows the first surgical instrument 220 to be housed in a narrower space. The reduced-size first surgical instrument 220 further reduces the obstruction of the surgeon's view of the surgical site. Another advantage of positioning the first alert module 255 away from the first surgical instrument 220 is that, especially in the case of a haptic device, the first alert module 255 provides an alert or notification to the surgeon without vibrating or affecting the movement of the first surgical instrument 220. During a highly technical surgery, an alert that vibrates the first surgical instrument 220 can startle the surgeon by the first alert module 255 and / or cause an unwanted movement of the first surgical instrument 220 due to the vibration, potentially causing the surgeon to move the first surgical instrument 220 to an undesired position.

[0054] The first surgical instrument assembly 200 can also include a tracking device 230. The tracking device 230 can be coupled to the handpiece 225 of the first surgical instrument 220. The tracking device 230 can have a plurality of markers 235 that can be identified by the tracking unit 110 of the surgical navigation system 100. The markers 235 can have passive tracking elements (e.g., reflectors) for transmitting an optical signal to a sensor(s) 115 (e.g., reflecting light emitted from the tracking unit 110). In other configurations, the markers 235 can be configured as active tracking markers, such as LEDs. Additionally, it is contemplated that the markers 235 can have a combination of active and passive arrangements. The markers 235 can be arranged at defined or known positions and orientations relative to other markers 235 such that the surgical navigation system 100 can determine, for example, the position and orientation (pose) of the surgical instrument 220 relative to a defined region of interest. For example, the markers 235 can be aligned with the first surgical instrument 220 such that the surgical navigation system 100 can determine the position and / or orientation of the end effector 240, or the cutting portion of the first surgical instrument 220, within a defined space such as the surgical field. In one exemplary configuration, the surgical navigation system 100 can be configured to determine the position and / or orientation of the end effector 240 or the cutting portion of the first surgical instrument 220 relative to a target trajectory and / or target position of a planned surgical path. In another exemplary configuration, the surgical navigation system 100 can further be configured to determine the position and / or orientation of the end effector 240 or the cutting portion of the first surgical instrument 220 relative to important anatomical structures within the patient's body, as well as the position and / or orientation relative to user-defined boundaries, zones, and / or regions.

[0055] Additionally, or alternatively, the surgical system 10 can have a second surgical instrument assembly 300 to be used with the navigation system 100. For example, the second surgical instrument assembly 300 may include a second surgical instrument 320 such as a high-speed surgical bar that includes a handpiece 325. The handpiece 325 is connectable to a console 310 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 that a surgeon grasps during the performance of a medical procedure. Exemplary second surgical instruments for connection to the console are described in U.S. Patent No. 10,016,209 and U.S. Patent Publication No. 20190117322, each of which is hereby incorporated by reference in its entirety.

[0056] The second surgical instrument 320 can further include a second instrument processor 315 and a drive motor 345. The second instrument processor 315 can be disposed within the console 310 of the second surgical instrument assembly 300. The drive motor 345 can be disposed within the handpiece 325 of the second surgical instrument 320. The second instrument processor 315 and the drive motor 345 can communicate with each other, and the second instrument processor 315 can be configured to control the operation of the drive motor 345 and, thus, the operation of the second surgical instrument 320. For example, the second surgical instrument 320 can be coupled to the console by a cord that connects the second instrument processor 315 to the drive motor 345, enabling communication between the second instrument processor 315 and the drive motor 345 and allowing the operation of the drive motor 345 to be controlled. Further, the second instrument processor 315 can include an end effector 340, such as a high-speed cutting bar. The end effector 340 can be coupled to the handpiece 325 of the second surgical instrument 320 such that the drive motor 345 can be operably coupled to the end effector 340. For example, the drive motor 345 can be configured to drive the high-speed cutting bar 340 to grind and / or remove biological tissue from a surgical site corresponding to the region of interest. The second instrument processor 315 can communicate with the drive motor 345 and can be configured to control the operation of the drive motor 345 and, thus, the high-speed cutting bar 340. Further, the second instrument processor 315 can communicate with the navigation processor 140 and can be configured to exchange data related to the position and / or orientation of the second surgical instrument 320 and data related to the operation of the second surgical instrument 320. For example, the second instrument processor 315 and the navigation processor 140 can be configured to communicate data related to the operation of the second surgical instrument 320 with each other based on the position and / or orientation of the second surgical instrument 320 detected by the surgical navigation system 100. It is also contemplated that additional surgical instruments can be coupled to the console and / or can communicate with the second instrument processor 315 disposed within the console 310.

[0057] The second surgical instrument assembly 300 can also have a power source (not shown). The power source can be coupled to the console 310 of the second surgical instrument assembly 300 and configured to supply energy to the drive motor 345 of the second surgical instrument 320 to drive the end effector 340. Further, it is contemplated that the console 310 can be provided with a cord configured to be plugged into an outlet connected to an electrical grid to supply energy to the second surgical instrument assembly 300. The power source can be configured to selectively power the drive motor 345 by communicating electrically with the second instrument processor 315 and / or the drive motor 345 to drive the end effector 340.

[0058] The second surgical instrument assembly 300 can also have a switch 350, such as a foot switch, a trigger, or a button, which is operably coupled to the second instrument processor 315. The switch 350 can be configured to generate a signal and / or communicate the signal to the second instrument processor 315 based on a user input that controls the operation of the second surgical instrument 320. For example, the switch 350 can include a first position, a second position, and a plurality of intermediate positions between the first and second positions. The first position can be configured as an off position such that when the second instrument processor 315 detects that the switch 350 is in the first position, the second instrument processor 315 blocks the flow of energy from the power source to the drive motor 345 to prevent the operation of the second surgical instrument 320. Conversely, the second position and the plurality of intermediate positions can each be configured as an on position. When the second instrument processor 315 detects that the switch 350 is in the second position, the second instrument processor 315 can be configured to allow the maximum flow of energy from the power source to the drive motor 345 so that the second surgical instrument 320 can operate at a maximum speed, such as a maximum cutting speed or a grinding speed. When the second instrument processor 315 detects that the switch 350 is in one of the intermediate positions, the second instrument processor 315 can be configured to allow the flow of energy from the power source to the drive motor 345 at a level corresponding to the position of the switch 350 between the first and second positions, enabling the second surgical instrument 320 to operate at an intermediate level of cutting or grinding speed. For example, when the second instrument processor 315 detects that the switch 350 is located at the midpoint (50%) between the first and second positions, the second instrument processor 315 can be configured to allow the flow of energy from the power source to the drive motor 345 at a level that enables the second surgical instrument 320 to operate at 50% of the maximum cutting speed or grinding speed. Alternatively, the second instrument processor 315 can be configured such that when the switch 350 is in a position other than the first position, the maximum flow of energy from the power source to the drive motor 345 is always allowed, enabling the second surgical instrument 320 to operate at the maximum speed or grinding speed when the switch 350 is in either the second position or an intermediate position.

[0059] Although not shown, it is contemplated that a plurality of surgical instruments 320 may be coupled to the console 310 and controllable by a foot switch. A switch 350, such as a foot switch, can be configured to control each of the plurality of surgical instruments. For example, a single foot switch may include a plurality of buttons, and each button may be assigned to one of the plurality of surgical instruments. An exemplary surgical system including a switch connected to a console for controlling a plurality of surgical instruments is disclosed in U.S. Patent Application No. 15 / 450,477, the entire disclosure of which is incorporated herein by reference.

[0060] The second surgical instrument assembly 300 can also include a second alert module 355. The second alert module 355 can include an audible, tactile, and / or visually perceptible device. The second alert module 355 can be configured to communicate with the second instrument processor 315, or directly with the navigation processor 140. The second instrument processor 315 or the navigation processor 140 can be configured to send a signal to activate the second alert module 355 to provide a warning or notification based on a pre-programmed condition or setting.

[0061] For example, as described above, the surgeon can use the user input device(s) 130 to select cortical boundaries, nerves, blood vessels, or similar important anatomical structures that the surgeon wishes to avoid, and input predetermined conditions and / or settings, such as for establishing boundaries or zones (e.g., zones to be excluded from cutting) surrounding these anatomical structures, into the surgical navigation system 100. Further, the surgeon can use the user input device(s) 130 to select and / or input a target position, a target region for resection, a target trajectory, or a similar shaped portion to assist in guiding the surgeon during the performance of a medical procedure. The second instrument processor 315 can be configured to transmit a signal to activate the second alert module 355 when the end effector 340 of the second surgical instrument 320 enters one of the regions and / or zones defined by the surgeon and surrounding an anatomical structure, based on data provided by the navigation processor 140. For example, the surgeon can use the user input device(s) 130 of the surgical navigation system 100 to define boundaries or zones for the anatomical model. This can include identifying important anatomical shaped portions, such as specific walls of a vertebral body, a central foramen, a nerve, or a blood vessel, and assigning it to a zone. As described above, the navigation system 100 can include a boundary generation unit for generating virtual boundaries within the patient related to important anatomical shaped portions. As part of generating such boundaries, the navigation system 100 can be configured to recognize and / or define virtual boundaries based on a segmentation algorithm. When the navigation system 100 generates one or more virtual boundaries, the navigation system 100 can be further configured to allow the surgeon to select a depth or distance. When the surgeon selects a depth, the navigation system 100 can be configured to project a second virtual boundary at the selected depth or distance from the original virtual boundary. The region and / or volume defined between the original virtual boundary and the second virtual boundary can define at least a portion of the zone. An exemplary system and / or method for segmentation is described in U.S. Patent Publication No. 2017 / 0061242, the entire disclosure of which is incorporated herein by reference.

[0062] The boundary generation unit can also identify additional zones including regions or areas surrounding important anatomical shape parts, such as defining a second zone that surrounds the important anatomical shape part separated from the boundary of the important anatomical shape part. The boundary generation unit can further define additional subsequent zones, such as a third zone that is separated from the boundary of the important anatomical shape part by a distance longer than the distance by which the second zone is separated from the important anatomical shape part and that surrounds the second zone. In this exemplary configuration, the end effector 340 is likely to first contact the outermost alert zone, thereby triggering the second alert module 355 to generate a first alert. Next, the end effector 340 can contact the alert zone that is next closest to the important anatomical structure, triggering the alert module 355 to generate a second alert. The first alert and the second alert are configured to notify the surgeon that the end effector 340 has entered the respective alert zones assigned to the first alert and the second alert. The surgical navigation system 100 can be configured to enable the surgeon to define alert zones (or multiple alert zones) or regions (or multiple regions) if required for a particular surgery. The alert zone can be configured as a boundary line or a region surrounding the important anatomical structure. For example, the alert zone (or multiple alert zones) can include a region or layer surrounding the important anatomical structure. The surgeon can define the thickness of the alert zone in the surgical navigation system 100. For example, the second alert zone adjacent to the important anatomical structure may be defined as a 2-millimeter-thick region surrounding the important anatomical structure. The thickness can be varied based on the type of surgery and / or the surgeon's preference so as not to surely contact the important anatomical structure. The surgeon can define a subsequent alert zone adjacent to the second alert zone and on the opposite side of the important anatomical structure, such that this subsequent alert zone can be made to be farther from the important anatomical structure than the second alert zone.

[0063] The surgeon can define the subsequent alert zone as a 5 - millimeter - thick region surrounding the outermost periphery of the second alert zone. Based on the type of surgery and / or the surgeon's preference, the user input device can be operated to adjust the thickness.

[0064] It will be understood that such alert zones may be automatically generated based on segmentation data from the patient scan.

[0065] The second instrument processor 315 can also be configured to send a signal to activate the second alert module 355 when the end effector 340 of the second surgical instrument 320 deviates from the trajectory and / or when the end effector 340 reaches the target position / zone / boundary, based on the data provided by the navigation processor 140. For example, based on the surgical navigation system 100 identifying that the end effector 340 and / or the second surgical instrument 320 is not properly aligned with the target trajectory established as part of the panned surgical path, the second alert module 355 can be activated to generate at least one of an audible, tactile, or visually perceivable alert. In this exemplary configuration, the second alert module 355 can generate a tactile alert, such as vibrating the switch 350 or a detachable power source, to notify the surgeon that the end effector 340 is not properly aligned with the target trajectory. Once the end effector 340 is properly aligned with the target trajectory, the second alert module 355 may be stopped. Similarly, the second alert module 355 can be configured to be activated to generate at least one of an audible, tactile, or visually perceivable alert based on the surgical navigation system 100 identifying that the end effector 340 and / or the second surgical instrument 320 has reached the target position determined by the surgeon. For example, the second alert module 355 may generate a tactile alert such as vibrating the switch 350 to notify the surgeon that the end effector 340 has reached the target position / zone, such as a suitable depth or position relative to an important anatomical boundary. It is also contemplated that the control console can be configured to stop the drive motor 345, and thus the end effector 340, so that the end effector 340 does not exceed the target position / zone once it reaches the target position.

[0066] In an exemplary configuration, the second alert module 355 can have a vibration device configured to contact a surgeon and vibrate to inform the surgeon of a specific condition or give a warning. In an exemplary configuration, as shown in FIG. 1, the second alert module 355 can include a vibration device coupled to a switch 350, such as a foot switch, that controls the operation of the second surgical instrument 320. The second alert module 355 can be configured to vibrate upon the occurrence of a predetermined condition. For example, the second alert module 355 may include a vibration device coupled to and / or communicating with the foot switch 350. In this configuration, the second alert module 355 can be configured to vibrate the foot switch 350 to notify the surgeon of the occurrence of a predetermined condition, such as when the end effector 340 of the second surgical instrument 320 approaches and / or enters one of the defined alert zones. When driving the second surgical instrument 320, the surgeon will always be in contact with the switch 350, so the surgeon should feel the second alert module 355 vibrate and be notified of the occurrence of the specified condition without affecting the grip of the handheld surgical instrument. The second alert module 355 can be configured to generate vibrations in a specific pattern or at intervals upon the occurrence of a predetermined condition. Alternatively, the second alert module 355 can be configured to generate a first vibration in a specific pattern or at specific intervals upon the occurrence of a first condition, and generate a second vibration in a different pattern or at different intervals upon the occurrence of a second condition. For example, the second alert module 355 can be configured to vibrate and stop alternately when the end effector 340 of the second surgical instrument 320 approaches and / or enters the first alert zone, and the second alert module 355 can be configured to vibrate continuously when the end effector 340 of the second surgical instrument 320 approaches and / or enters the second alert zone.

[0067] The second alert module 355 can further be configured as an audible device, such as a speaker, configured to supply an audible alert to the surgeon upon occurrence of a predetermined state. For example, the second alert module 355 can have a speaker configured to generate a specific voice upon occurrence of a predetermined state. Alternatively, the second alert module 355 can have a speaker configured to generate voice in a specific pattern or at specific intervals upon occurrence of a predetermined state, such as when the position of the end effector exceeds a predetermined zone / boundary.

[0068] As yet another configuration, the second alert module 355 can be configured as a visually recognizable device, such as a visual display, configured to supply a visual alert to the surgeon upon occurrence of a predetermined state. For example, the second alert module 355 can have illumination configured to blink upon occurrence of a predetermined state. Alternatively, the second alert module 355 can have a plurality of multi-color illuminations configured to illuminate and / or blink in a predetermined color or pattern upon occurrence of a predetermined state. The display can be integrated into the handpiece 325 or the battery, or as part of the navigation system 100, or a combination thereof.

[0069] Furthermore, it is also contemplated that the second alert module 355 can have a combination of audible, tactile, and / or visually perceptible devices. For example, the second alert module 355 can be configured as a combination of an audible device and a tactile device, in which case the tactile device can be configured to vibrate to provide a first alert, and the audible device can be configured to generate noise to provide a second alert. The first alert and the second alert may indicate the occurrence of the same predetermined state, or alternatively, the first alert and the second alert may indicate the occurrence of different predetermined states. For example, the first alert can be based on the entry of the second surgical instrument 320 into the first region, and the second alert can be based on the entry of the end effector 340 into the second region.

[0070] Furthermore, it is contemplated that the second alert module 355 can be configured as a software routine configured to control an audible, tactile, and / or visually perceivable device. The software routine can also be configured to control a combination of audible, tactile, and / or visually perceivable devices. For example, the software routine can include instructions stored in a memory accessible to the surgical navigation system 100, one or more of the surgical instrument assemblies 200, 300, 400, and / or other elements of the surgical system 10.

[0071] Although the second alert module 355 is shown coupled to the switch 350 of the second surgical instrument assembly 300, it is also contemplated that the second alert module 355 can be coupled and / or positioned at other locations. For example, if the second alert module 355 includes a tactile device, the second alert module 355 can be configured as a vibrating member removably attached to the surgeon. The second alert module 355 can be configured as a bracelet worn on the surgeon's wrist or arm so that the surgeon can feel the second alert module 355 vibrate when a predetermined condition occurs. Alternatively, if the second alert module 355 includes an audible device, the second alert module 355 can be configured as a speaker removably attached to the surgeon. The second alert module 355 can be configured as a Bluetooth-enabled speaker or earpiece worn on the surgeon's head or positioned in the surgeon's ear so that the surgeon can hear the noise emitted by the second alert module 355 when a predetermined condition occurs.

[0072] The second surgical instrument assembly 300 can also have a tracking device 330. The tracking device 330 can be coupled to the handpiece 325 of the second surgical instrument 320. The tracking device 330 is similar to that described above for the first surgical instrument assembly 200.

[0073] The surgical system 10 can have a third surgical instrument assembly 400 that communicates with the navigation system 100. For example, the third surgical instrument assembly 400 can have a third surgical instrument 420, such as an ultrasonic instrument that includes a handpiece 425. The handpiece 425 can 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 can be shaped to include a handle or grip portion for a surgeon to hold during the performance of a medical procedure.

[0074] The third surgical instrument 420 can further include a third instrument processor 415 and a drive motor 445. The third instrument processor 415 can be disposed within the console 410 of the third surgical instrument assembly 400. The drive motor 445 can be disposed within the handpiece 425 of the third surgical instrument 420. The third instrument processor 415 and the drive motor 445 can communicate with each other. The drive motor 445 can have a piezoelectric element configured to expand and contract upon application of an electric current to the piezoelectric element. The piezoelectric element can include a plurality of disc-shaped piezoelectric elements stacked end-to-end. The third instrument processor 415 can be configured to control the drive motor 445 and, thus, the operation of the third surgical instrument 420. For example, the third surgical instrument 420 can have an end effector 440, such as an ultrasonic tip assembly. The end effector 440 can include an ultrasonic tip assembly that includes a horn in which an ultrasonic tip portion vibrates at ultrasonic speed when the piezoelectric element(s) expands and contracts. Further, the ultrasonic tip assembly can include an outer sheath disposed at least in part on the horn excluding the ultrasonic tip portion. The end effector 440 can be coupled to the handpiece 425 of the third surgical instrument 420 such that the drive motor 445 can be operably coupled to the end effector 440. For example, the drive motor 445 can be configured to drive the ultrasonic tip assembly 440 to grind and / or remove biological tissue from the surgical site. The third instrument processor 415 can communicate with the drive motor 445 and can be configured to control the flow of electric current to the piezoelectric element(s) to control the operation of the drive motor 445 and, thus, the ultrasonic tip assembly 440. Further, the third instrument processor 415 can communicate with the navigation processor 140 and can be configured to exchange data related to the position and / or orientation of the third surgical instrument 420 and data related to the operation of the third surgical instrument 420. For example, the third instrument processor 415 and the navigation processor 140 can be configured to communicate with each other data related to the operation of the third surgical instrument 420 based on the position and / or orientation of the third surgical instrument 420 detected by the surgical navigation system 100.

[0075] The third surgical instrument assembly 400 can also have a power source (not shown). The power source is coupled to the console 410 of the third surgical instrument assembly 400 and can be configured to supply energy to the drive motor 445 of the third surgical instrument 420 to drive the end effector 440. For example, the power source can have a detachable battery pack. Additionally, it is contemplated that the console 410 can be provided with a cord configured to be plugged into an outlet connected to an electrical grid to supply energy to the third surgical instrument assembly 400. The power source can be configured to selectively supply power to the drive motor 445 by communicating electrically with the third instrument processor 415 and / or the drive motor 445 to drive the end effector 440.

[0076] The third surgical instrument assembly 400 can also have a switch 450, such as a footswitch, pedal, or button, operably coupled to the third instrument processor 415, which can be similar to the aforementioned switch 350.

[0077] The third surgical instrument assembly 400 can also include a third alert module 455. The third alert module 455 can include audible, tactile, visually perceivable devices, and / or software routines. The third alert module 455 can be configured to communicate with the third instrument processor 415. The third instrument processor 415 can be configured to send a signal to activate the third alert module 455 to provide a warning or notification based on pre-programmed conditions or settings.

[0078] As described above, the surgeon can use the user input device(s) 130 to select and / or input the target position of the surgical path, the target region of resection, the target trajectory, or a similar shaped part to assist in guiding the surgeon during the performance of a medical procedure, which can be used to establish a target region or zone. The third instrument processor 415 is configurable to send a signal to activate the third alert module 455 when the end effector 440 of the third surgical instrument 420 enters one of the regions and / or zones defined by the surgeon that surround the anatomical structure, based on the data provided by the navigation processor 140. The third instrument processor 415 is also configurable to send a signal to activate the third alert module 455 when the end effector 440 of the third surgical instrument 420 deviates from the trajectory and / or when the end effector 440 reaches the target position, based on the data provided by the navigation processor 140. For example, based on the surgical navigation system 100 identifying that the end effector 440 and / or the third surgical instrument 420 is not properly aligned with the target trajectory established as part of the planned surgical path, the third alert module 455 can be activated to generate at least one of an audible, tactile, or visually perceivable alert. In this exemplary configuration, the third alert module 455 can generate a tactile alert, such as by vibrating the switch 450, to notify the surgeon that the end effector 440 is not properly aligned with the target trajectory. Once the end effector 440 is properly aligned with the target trajectory, the third alert module 455 may be stopped. Similarly, the third alert module 455 is configurable to be activated to generate at least one of an audible, tactile, or visually perceivable alert based on the surgical navigation system 100 identifying that the end effector 440 and / or the third surgical instrument 420 has reached the target position determined by the surgeon in the planned surgical path.For example, to notify the surgeon that the end effector 440 has reached a target position such as a suitable depth, the third alert module 455 may generate a tactile alert such as vibrating the switch 450. When the end effector 440 reaches the target position, it is also contemplated that the console 410 may be configured to stop the drive motor 445 and, thus, the end effector 440 so that the end effector 440 does not exceed the target position.

[0079] In one exemplary configuration, the third alert module 455 may be configured as described above for the first alert module 255 and the second alert module 355.

[0080] The third surgical instrument assembly 400 can also include a tracking device 430. The tracking device 430 can be coupled to the handpiece 425 of the third surgical instrument 420. The tracking device 430 can be similar to that defined above for other surgical instrument assemblies 200, 300 (including, for example, a plurality of markers 435, etc.).

[0081] The above-described surgical instrument assemblies 200, 300, 400 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 also contemplated. The plurality of exemplary surgical instrument assemblies 200, 300, 400 are described as being part of the surgical system 10 and communicating with the surgical navigation system 100, but it is contemplated that the surgical system 10 can have only a single surgical instrument assembly 200, 300, 400 and navigation system 100. Further, although 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 can be configured to include any combination of surgical instrument assemblies 200, 300, 400 and / or surgical navigation system 100. For example, the surgical system 10 can have a single surgical instrument assembly 200, 300, 400 and multiple surgical navigation systems 100.

[0082] Referring to FIG. 2, an exemplary configuration of an operating room or surgical facility for performing a medical procedure on a patient 20 using the above-described surgical system 10 is illustrated. The surgical system 10, including the surgical navigation system 100 and at least one of the above-described surgical instrument assemblies 200, 300, 400, can be positioned in an operating room surrounding the patient 20 and / or the surgical site 30 where the medical procedure is to be performed.

[0083] In FIG. 2, only the second surgical instrument assembly 300 is illustrated, but it should be understood that this is merely an exemplary configuration of the surgical system 10, and any number of surgical instrument assemblies 200, 300, 400 are contemplated to be positionable within the operating room. As described above, the second surgical instrument assembly 300 includes a second surgical instrument 320 that includes an end effector 340 and a tracking device 330. The tracking device 330 includes a plurality of markers 335 that can be identified and / or tracked by the surgical navigation system 100. The second surgical instrument 320 is coupled to a console 310 that is located at a position remote from the second surgical instrument 320. Further, the second surgical instrument assembly 300 also includes a switch 350 that is positioned away from the patient 20 and is coupled to the console 310. The switch 350 communicates with the second surgical instrument 320 via a second instrument processor 315 (not shown) stored within the console 310.

[0084] Although not previously described, it is also contemplated that the surgical system 10 may further include an imaging system 500 such as a CT or MRI imaging device. The imaging system 500 can have a scanner 510 and a display unit 520. The scanner 510 can be used to take images of the surgical site 30 of the patient 20 and display them on the display unit 520. For example, the scanner can have a C-arm configured to rotate around the patient 20 to generate a plurality of images of the surgical site 30. Further, the imaging system 500 can also have a processor (not shown) having software that can image a plurality of images captured by the scanner 510 and generate a two-dimensional image and / or a three-dimensional model of the surgical site 30. The display unit 520 can be configured to display the final two-dimensional image and / or three-dimensional model.

[0085] Furthermore, the imaging system 500 can communicate with the navigation processor 140 of the surgical navigation system 100. The imaging system 500 can be configured to communicate with the navigation processor 140 via a wired and / or wireless connection. For example, the imaging system 500 can be configured to supply preoperative and / or intraoperative image data, such as the final two-dimensional image and / or three-dimensional model of the surgical site 30, to the navigation processor 140. Next, the navigation processor 140 can be configured to supply the final two-dimensional image and / or three-dimensional model to the navigation display unit 120. In this case, the surgeon can use the user input device(s) 130 or an algorithm to identify and / or define the corresponding regions and / or zones around the important anatomical structures. For example, the surgeon can use the user input device(s) 130 of the surgical navigation system 100 to define an alert zone around a vertebral body, nerve, or blood vessel that the surgeon wishes to avoid during a medical procedure. The surgeon can use the user input device(s) 130 of the surgical navigation system 100 to input and / or modify the planned surgical path, boundary, or alert zone to be used during the execution of a medical procedure.

[0086] Referring to FIG. 3, an exemplary block diagram of the surgical system 10 is shown. According to the example shown, the surgical system 10 further includes a navigation system 100, or more specifically, a control system 141 that communicates with the navigation processor 140 of the navigation system 100, and the navigation system 100 communicates with a GUI 150. The control system 141 also communicates with one or more of the instrument assemblies 200, 300, 400. Specifically, the control system 141 can communicate with one or more of the surgical instruments 220, 320, 420, and / or one or more of the consoles 310, 410 of the instrument assemblies 200, 300, 400, or more specifically, one or more of the instrument processors 215, 315, 415 of these components. The control system 141 can further communicate with one or more of the alert modules 255, 355, 455 of the instrument assemblies 200, 300, 400, and those alert modules can communicate with one or more of the switches 250, 350, 450 of the instrument assemblies 200, 300, 400.

[0087] The control system 141 may include or be implemented by one or more controllers or one or more processors, each of which may be configured to operate under the control of a software routine or program embodied by one or more computer-executable instructions stored in a memory accessible to the controller or processor. The computer-executable instructions may be configured to implement the functions, features, processes, and routines of the control system 141 described herein when executed by one or more controllers or processors. As shown in the example presented, the control system 141 is separated from other components of the surgical system 10, such as the navigation system 100 and / or the instrument assemblies 200, 300, 400, and can communicate with them. In an alternative embodiment, the control system 141, or more specifically, the functions, features, processes, and routines of the control system 141 described herein, may be implemented by one or more other components of the surgical system 10, such as the navigation system 100, or more specifically, one or more of the navigation processor 140 and / or the instrument assemblies 200, 300, 400, or more specifically, one or more of the instrument processors 215, 315, 415. That is, the control system 141, or more specifically, the functions, features, processes, and routines of the control system 141 described herein, may be distributed across multiple devices or systems of the surgical system 10 and thus may be considered to form the control system 141.

[0088] The control system 141 can be configured to control the outputs of the navigation system 100 and the alert modules 255, 355, 455 according to the tracked postures of the surgical instruments 220, 320, 420 in a known coordinate system with reference to virtual boundaries and / or zones. Further, the control system 141 can be configured to identify a shielding event (introduced below) and control the output of the navigation system 100 according to the shielding event. The control system 141 can also be configured to control the alert modules 255, 355, 455 and / or the drive motors 245, 345, 445 of the instrument assemblies 200, 300, 400 based on the shielding event and / or based on one or more characteristics of the shielding event. For example, the control system 141 can be configured to adjust the drive speed of the drive motors 245, 345, 445 from a current non-zero value, which is, for example, a value set by the surgeon, to another non-zero value. The another non-zero value is slower than the current non-zero value and / or may not be able to treat the tissue in the region of interest generally. Additionally or alternatively, the control system 141 can be configured to deactivate and stop the drive motors 245, 345, 445 based on the shielding event and / or based on one or more characteristics of the shielding event.

[0089] After controlling the alert modules 255, 355, 455 and / or the drive motors 245, 345, 445 based on the occlusion event, the control system 141 continues to monitor the occlusion event and maintains the state of the alert modules 255, 355, 455 and / or the drive motors 245, 345, 445 until it detects that the occlusion event has been resolved through updated tracking data from the tracking unit 110 or, alternatively, until it receives an input from the surgeon to deactivate the occlusion monitoring. Thereafter, the control system 141 can be configured to stop the operation of the alert modules 255, 355, 455 and / or resume the operation of the drive motors 245, 345, 445. In some embodiments, the surgeon can temporarily deactivate the occlusion monitoring, for example, for a predefined duration, thereby also stopping the operation of the alert modules 255, 355, 455 and / or resuming the operation of the drive motors 245, 345, 445, such as by switching the associated switches 250, 350, 450 to the off position and then back to the on position.

[0090] In some examples, the surgical system 10 can also include a location loss of awareness (LLA) indicator 142 that communicates with the control system 141. In such examples, the control system 141 is configured to control the LLA indicator 142 based on the presence of an occlusion event, as described further below. The LLA indicator 142 can be a visually perceivable device, such as a visual display, a light-emitting diode (LED), or any other suitable alternative. The LLA indicator 142 can also be an auditory device and / or a tactile device, or it can be a software routine. A software routine is a set of instructions stored in memory and can be configured to control an audible, tactile, and / or visually perceivable device. A software routine can also be configured to control a combination of audible, tactile, and / or visually perceivable devices. For example, a software routine can include computer-executable instructions stored in memory accessible to one or more of the surgical navigation system 100, the surgical instrument assemblies 200, 300, 400, and / or other elements of the surgical system 10.

[0091] Referring to FIGS. 4 and 5, a schematic diagram of the surgical system 10 during the performance of a medical procedure is shown. This schematic diagram of the surgical system 10 includes any one of the surgical instruments 220, 320, 420 described above for the purpose of further explaining the operation of the surgical system 10, which has various orientations with respect to the patient 20, and more specifically, the surgical site 30 of the patient 20.

[0092] As described above, the surgeon can use the surgical navigation system 100 to identify and / or define various boundaries, regions, target trajectories, or target positions, etc. in preoperative and / or intraoperative patient data corresponding to the region of interest of the medical treatment, such as in a CT scan or an MRI scan. For example, the surgeon can use the surgical navigation system 100 to select and / or define one or more virtual boundaries (Boundary 1, 2, 3, 4) and / or one or more alert zones (Zone 1, 2, 3, 4) based on important anatomical structures or boundaries such as the central foramen, vertebral wall, nerve, or blood vessel present at the surgical site 30. This may include defining a plurality of virtual boundaries (Boundary 1, 2, 3, 4) and / or alert zones (Zone 1, 2, 3, 4) at various distances from the important anatomical structures and / or regions of interest. For example, in the examples shown in FIGS. 4 and 5, the surgical site 30 includes the vertebra where the medical treatment is performed, and the virtual boundaries (Boundary 1, 2, 3, 4) can be defined based on the outer edge of the spinal cord. The virtual boundaries (Boundary 1, 2, 3, 4) can be manually defined by the surgeon using the navigation system 100. However, the virtual boundaries (Boundary 1, 2, 3, 4) can also be selected by the surgeon from a list of pre-created virtual boundaries provided by the boundary generation software of the navigation system 100. The boundary generation unit can also be configured to define one or more alert zones (Zone 1, 2, 3, 4) based on important anatomical structures and / or regions of interest. An exemplary method of setting and / or defining virtual boundaries and alert zones is described in International Patent Publication No. WO 2021 / 062373, the entire content of which is incorporated herein by reference.

[0093] In a medical procedure for removing biological tissue from a surgical site, the end effectors 240, 340, 440 of the predetermined surgical instruments 220, 320, 420 may approach any of various virtual boundaries (Boundary 1, 2, 3, 4), alert zones (Zone 1, 2, 3, 4), and / or target depth (T). As described above, the surgical navigation system 100 tracks the position and / or orientation (posture) of the surgical instruments 220, 320, 420 based on various virtual boundaries (Boundary 1, 2, 3, 4), alert zones (Zone 1, 2, 3, 4), and / or target depth (T), sends signals or commands to the instrument processors 215, 315, 415 associated with the predetermined surgical instruments 220, 320, 420, activates the alert modules 255, 355, 455 associated with the predetermined surgical instruments 220, 320, 420, and is configured to notify the surgeon when the end effectors 240, 340, 440 approach and / or enter any of the various virtual boundaries (Boundary 1, 2, 3, 4), alert zones (Zone 1, 2, 3, 4), and / or target depth (T). The alert modules 255, 355, 455 can be configured to provide specific alerts or combinations of alerts according to the types of alerts assigned to their respective boundaries (Boundary 1, 2, 3, 4) and / or alert zones (Zone 1, 2, 3, 4). The surgical navigation system 100 is also configured to operate / control the speed of the drive motors 245, 345, 445 associated with the predetermined surgical instruments 220, 320, 420, and thus the speed at which the end effectors 240, 340, 440 operate, based on the position and / or orientation of the surgical instruments 220, 320, 420 with respect to one or more of the virtual boundaries (Boundary 1, 2, 3, 4), alert zones (Zone 1, 2, 3, 4), and / or target depth (T). For example, the surgical navigation system 100 can be configured to stop the drive motors 245, 345, 445 or decelerate them from the maximum cutting speed to the minimum cutting speed based on the position of the surgical instruments 220, 320, 420 with respect to one or more virtual boundaries (Boundary 1, 2, 3, 4), alert zones (Zone 1, 2, 3, 4), and / or target depth (T).

[0094] When end effectors 240, 340, 440 are adjacent to any of the virtual boundaries and / or are located distal thereto and / or enter any of the various alert zones, when the surgical navigation system 100 transmits a signal to stop or decelerate the variable speed drive motors 245, 345, 445 to the processors 215, 315, 415 of the surgical instruments 220, 320, 420, the processors 215, 315, 415 are configured to decelerate or stop the variable speed drive motors 245, 345, 445, and in the latter case, to stop, for example, by rotating the drive motors 245, 345, 445 at 0 rpms. The processors 215, 315, 415 are configured to restart the variable speed drive motors 245, 345, 445 and return them to the speed etc. before deceleration or stop after temporarily stopping or decelerating the variable speed drive motors 245, 345, 445 while the end effectors 240, 340, 440 are in a position adjacent to any of the virtual boundaries and / or in a distal position thereto and / or staying in any of the various alert zones. In some cases, the variable speed drive motors 245, 345, 445 can be restarted by the processors 215, 315, 415 after a predetermined time, for example, after 1 second, 2 seconds, 3 seconds, or 4 seconds have elapsed. Alternatively, after the processors 215, 315, 415 receive a signal that the user has performed an operation such as switching a switch 250, 350, 450 associated with a predetermined surgical instrument 220, 320, 420 from the on position to the off position and then back to the on position, the variable speed drive motors 245, 345, 445 can be restarted by the processors 215, 315, 415.

[0095] More specifically, when the end effectors 240, 340, 440 cross and / or approach the defined virtual boundaries (boundaries 1, 2, 3, 4), the defined alert zones (zones 1, 2, 3, 4), and / or the defined target depth (T), the control system 141 can be configured to cause the alert modules 255, 355, 455 to alert the surgeon and / or to control the drive motors 245, 345, 445. The nested configuration of boundaries 1, 2, 3, and 4 and zones 1, 2, 3, and 4 (where one is positioned more distally than the other with respect to the region of interest) provides increasingly more alerts in a stepwise manner, enabling the surgeon to reliably recognize that the surgical instruments 220, 320, 420 are in close proximity to important anatomical structures and / or the target depth (T) associated with the region of interest. The alert modules 255, 355, 455 can be configured to provide specific alerts or combinations of alerts depending on the type of alert assigned to the respective alert zones (zones 1, 2, 3, 4) and / or virtual boundaries (boundaries 1, 2, 3, 4).

[0096] As can be seen from the figure (e.g., FIG. 5), the surgical instruments 220, 320, 420 can be configured to drill holes to remove biological tissue from the region of interest in the surgical site 30 and / or drive screws such as pedicle screws into the region of interest in the surgical site 30. In this scenario, the surgeon can select and / or define the planned posture of the implant, such as the planned posture of one or more screws including the axis T as the target trajectory and the target depth (T). Alternatively, the navigation processor 140 can also receive the planned surgical path, which is automatically generated based on the segmentation of the patient image data and the planned posture of the medical device or implant 275 (FIG. 9) inserted during the surgery. When the end effectors 240, 340, 440 deviate from the axis T as the target trajectory and / or exceed and / or approach the target depth (T), the control system 141 can be configured to cause the alert modules 255, 355, 455 to alert the surgeon and / or control the drive motors 245, 345, 445.

[0097] An exemplary method of controlling the motor of the instrument and / or alerting the surgeon based on the position of the instrument relative to the virtual boundary, alert zone, target trajectory, and / or target depth is described in International Patent Publication No. 2021 / 062373, the entire disclosure of which is incorporated herein by reference.

[0098] In the process of tracking the surgical instruments 220, 320, 420, and thus the end effectors 240, 340, 440, it is contemplated that the tracking devices 230, 330, 430 of the surgical instruments 220, 320, 420 and / or the patient tracking device PT may be blocked from the view of the navigation system 100 (e.g., the tracking unit 110). For example, if the surgical instruments 220, 320, 420 are hand-held instruments, the surgeon may move the instruments 220, 320, 420 outside the view of the tracking unit 110. In another example, the surgeon may enter between the tracking unit 110 and the surgical instruments 220, 320, 420. In yet another example, the tracking devices 230, 330, 430 associated with a given surgical instrument 220, 320, 420 may include active tracking markers associated with the given surgical instrument 220, 320, 420 that are powered by a power source 260. If the power supplied from the power source 260 is interrupted, the tracking devices 230, 330, 430 may not be able to output tracking signals to the tracking unit 110. In yet another example, the tracking unit 110 may not be able to recognize the posture of the surgical instruments 220, 320, 420 due to problems associated with the tracking unit 110 itself. Regardless of the cause, the control system 141 is configured to determine whether the line of sight between the tracking unit 110 and any of the tracking devices 230, 330, 430 of the surgical instruments 220, 320, 420 and / or the patient tracking device PT is blocked, for example, based on tracking data received from the tracking unit 110 indicating that fewer markers than all the markers of the tracking devices 230, 330, 430 are detected. Such a blockage is herein referred to as a blockage event. The control system 141 can generally communicate with the tracking unit 110, the alert modules 255, 355, 455, and the consoles 310, 410 (if applicable). If the surgical instrument assemblies 200, 300, 400 do not include a console (e.g., the surgical instrument 220), the control system 141 can communicate with the surgical instruments 220, 320, 420 and / or the instrument processors 215, 315, 415 associated with the surgical instruments 220, 320, 420.

[0099] The control system 141 can be configured to control the alert modules 255, 355, 455 and / or drive motors 245, 345, 445 associated with a given surgical instrument 220, 320, 420 targeted by a shielding event based on one or more characteristics of the shielding event. The characteristics of this shielding event can include one or more characteristics of the shielding event itself (e.g., duration and / or cause of the shielding event) and / or one or more characteristics of the surgical instruments 220, 320, 420 associated with the shielding event, for example, characteristics during and / or before the shielding event, more specifically, characteristics immediately before the shielding event. This immediately preceding characteristic can correspond to one or more postures of the surgical instruments 220, 320, 420 that the navigation system 100 last observed before the shielding event, according to the tracked postures of the surgical instruments 220, 320, 420 in a known coordinate system. For example, the control system 141 can consider the cause of the shielding event, the duration of the shielding event, the orientation or posture of the surgical instruments 220, 320, 420 before the shielding event, the distance between the instruments 220, 320, 420 and a virtual boundary or region of interest before the shielding event, the direction of movement of the instruments 220, 320, 420 relative to the region of interest before the shielding event (e.g., towards or away from the region of interest), the speed, velocity, or acceleration of the instruments 220, 320, 420 before the shielding event, the movement parameters of the instruments 220, 320, 420 before the shielding event, and / or user input received during the shielding event for controlling the operation of the drive motors 245, 345, 445. Other factors not listed here can also be considered. By way of example, and as described in more detail below, the control system 141 may determine not to alert the surgeon and not to change the operation of the instruments 220, 320, 420 if the shielding event is shorter than a pre-determined duration threshold and during which the instruments 220, 320, 420 are at least a certain specific distance away from the patient's region of interest and / or virtual boundary.

[0100] The characteristics of the occlusion event, such as the characteristics of the occlusion event itself and / or the characteristics of the surgical instruments 220, 320, 420 associated with the occlusion event (e.g., during and / or prior to the occlusion event), can be useful indicators as to whether the occlusion event has or may cause an unacceptable level of uncertainty in the surgical system 10. As briefly described above, the characteristics of the occlusion event can include, among several characteristics, in particular, the cause of the occlusion event, the duration of the occlusion event, the posture of the surgical instruments 220, 320, 420 prior to the occlusion event, the distance between the instruments 220, 320, 420 and the virtual boundary or region of interest prior to the occlusion event, the orientation or direction of movement of the instruments 220, 320, 420 relative to the virtual boundary or region of interest prior to the occlusion event, the speed, velocity, or acceleration of the instruments 220, 320, 420 prior to the occlusion event, and / or the motion parameters of the instruments 220, 320, 420 prior to the occlusion event. Depending on the particular circumstances present during the use of the surgical instruments 220, 320, 420, different characteristics can be considered by the control system 141.

[0101] In the first example, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 associated with instruments 220, 320, 420 that are the subject of a shielding event, based only on the duration of the shielding event. More specifically, control system 141 can be configured to compare the duration of the shielding event with a set duration threshold and, based on that comparison, control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455. In this way, control system 141 can be configured to ignore any shielding event if the duration of the shielding event is shorter than the duration threshold. On the other hand, if the shielding event continues for longer than the duration threshold, control system 141 can alert the surgeon (e.g., using alert modules 255, 355, 455) and / or control drive motors 245, 345, 445 of surgical instruments 220, 320, 420. The duration threshold can be a specific time, for example, 0.001 seconds. Alternatively, the duration threshold can be determined based on the type of surgical instruments 220, 320, 420 being used and / or the surgery being performed using instruments 220, 320, 420. For example, the duration threshold can be 0.001 seconds when operating on a patient's spine and 0.01 seconds when operating on a patient's knee.

[0102] In a second example, the control system 141 is configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455, for example, by determining a positional relationship or distance between the instrument and the region of interest based on the tracked poses of the instruments 220, 320, 420 that are the subject of the occlusion event and a virtual boundary in a known coordinate system prior to the occlusion event. Specifically, the control system 141 can be configured to determine the distance between the surgical instruments 220, 320, 420 and each virtual boundary in a known coordinate system and identify a distance threshold corresponding to each distance. In such an example, in response to the distance between the instruments 220, 320, 420 and each virtual boundary associated with the region of interest exceeding the corresponding distance threshold, the surgical instruments 220, 320, 420 can be considered less likely to have an unexpected impact during the occlusion event. Thus, the control system 141 can be configured not to alert for any occlusion event. Alternatively, in response to the distance between the instruments 220, 320, 420 and any of the virtual boundaries associated with the region of interest being less than or equal to the corresponding distance threshold, the surgical instruments 220, 320, 420 can be considered more likely to have an unexpected impact during the occlusion event. Thus, the control system 141 can be configured to alert the surgeon via the alert modules 255, 355, 455 for any occlusion event and / or control the drive motors 245, 345, 445 associated with the occlusion event. The distance threshold can be a specific distance, for example, 1 millimeter. Alternatively, the distance threshold can be determined based on the type of surgical instruments 220, 320, 420 used, and / or the surgery being performed with the instruments 220, 320, 420, and / or the region of interest associated with the virtual boundary. For example, the distance threshold can be 5 to 10 millimeters when operating on the patient's spine and 1 millimeter when operating on the patient's knee. The distance threshold can be much larger (e.g., 1 meter) when there is a high concern about the occlusion event for the surgeon and / or the patient.

[0103] The distance between the surgical instruments 220, 320, 420 and each virtual boundary can be calculated as a straight line between the end effectors 240, 340, 440 of the surgical instruments 220, 320, 420 and the closest point on the virtual boundary. In some cases, this straight line may be orthogonal to a point on the mesh of the virtual boundary. Further, any of the distance calculations, including those described later, can be used to determine whether the surgical instruments 220, 320, 420 have crossed the virtual boundary and are currently in the alert zone (e.g., zones 1, 2, 3, or 4) and / or region of interest, and / or whether the surgical instruments 220, 320, 420 are within a range of a distance threshold based on the virtual boundary, such that as a result, it should be understood that the surgeon should be alerted about a shielding event.

[0104] The distance between the surgical instruments 220, 320, 420 and the virtual boundary can also be calculated by a specific method based on the type of the end effectors 240, 340, 440 that the instruments 220, 320, 420 are driving, or the type of the instruments 220, 320, 420 being used. When the end effectors 240, 340, 440 are bars (e.g., FIG. 4), for example, the control system 141 can be configured to calculate the distance as the distance between the center of the heads of the bars 240, 340, 440 and a point on the virtual boundary, e.g., a point on the mesh of the virtual boundary. However, the distance may be a scalar value, i.e., a value without a direction. Therefore, the control system 141 cannot determine whether the bars 240, 340, 440 are 1 mm away from the virtual boundary or outside the virtual boundary by 1 mm, or whether they are 1 mm inside the virtual boundary or inside the virtual boundary by 1 mm and located within the region of interest. To determine whether the bars 240, 340, 440 are 1 mm away from the virtual boundary or 1 mm inside the virtual boundary, the control system 141 can utilize ray casting to determine the direction, thereby further distinguishing the distance. Ray casting may include, for example, emitting a ray of light from the center of the bars 240, 340, 440 towards the shafts of the bars 240, 340, 440 and towards the handpieces 225, 325, 425 of the instruments 220, 320, 420 in a known coordinate system. If the ray of light collides with the virtual boundary, the control system 141 can assume that the bars 240, 340, 440 are 1 mm inside the virtual boundary and are in a potentially dangerous position based on the patient's anatomical structure that defines the region of interest. It is safe to assume so because when the center of the bars 240, 340, 440 is inside the region surrounded by the virtual boundary, the virtual boundary will surround at least a part of the shafts of the bars 240, 340, 440. Therefore, the ray of light emitted towards the shafts of the bars 240, 340, 440 will collide with the boundary when at least a part of the shaft is inside the boundary. Even when only the bar heads 240, 340, 440 are inside the boundary, the ray of light emitted from the center of the bar will also collide with the boundary.On the other hand, when the light beam does not collide with the virtual boundary, the control system 141 can assume that the bars 240, 340, 440 are 1 mm away from the virtual boundary. The control system 141 can be configured to control the alert modules 255, 355, 455 to indicate such a situation in the case where the light beam intersects the boundary. In such an example, the control system 141 can be configured such that the alert modules 255, 355, 455 can continue to issue alerts when the end effectors 240, 340, 440 enter the boundary based on the intersection of the light beam. That is, the control system 141 can control the alert modules 255, 355, 455 based on the intersection of the light beam, the postures of the instruments 220, 320, 420, and the boundary.

[0105] Furthermore, when the end effectors 240, 340, 440 are drill bits (e.g., FIG. 5), the control system 141 can perform in a manner similar to the above-described method that requires ray casting. However, the control system 141 can be configured to calculate the distance between the tip of the drill bits 240, 340, 440 and the virtual boundary instead of calculating the distance from the center of the bar. Thereafter, the control system 141 can be configured to determine the direction of the distance by emitting a light ray from the tip of the drill bits 240, 340, 440 towards the handpieces 225, 325, 425 along the remaining portion of the drill bits 240, 340, 440. Similarly, when the light ray collides with the virtual boundary, the control system 141 can assume that the drill bits 240, 340, 440 are in a potentially dangerous position based on the patient's anatomical structure that defines the region of interest because the drill bits 240, 340, 440 are 1 mm into the virtual boundary or within 1 mm of the virtual boundary. Alternatively, when the light ray does not collide with the virtual boundary, the control system 141 can assume that the drill bits 240, 340, 440 are 1 mm away from the virtual boundary. It should be understood that the specific distance (e.g., 1 mm) used here is merely an example, and the control system 141 can utilize the above method for other distances. The control system 141 can be configured to control the alert modules 255, 355, 455 to indicate such a situation in the case where the light ray intersects the boundary. In such an example, the control system 141 can cause the alert modules 255, 355, 455 to continuously issue an alert when the end effectors 240, 340, 440 enter the boundary based on the intersection of the light ray. That is, the control system 141 can be configured to control the alert modules 255, 355, 455 based on the intersection of the light ray, the posture of the instruments 220, 320, 420, and the boundary.

[0106] Furthermore, when end effectors 240, 340, 440 are drivers for driving screws (e.g., FIG. 6), the control system 141 can be configured to calculate the distance as the distance between the tip of the drivers 240, 340, 440 and the center of the planned position of the screw 275, which can also be represented by a virtual boundary. When actively attempting to drive the screw 275 connected to the drivers 240, 340, 440 into the patient, this distance can instead be the distance between the tip of the screw 275 attached to the drivers 240, 340, 440 and the center of the planned position of the screw 275. For example, FIG. 9 shows the planned position of the screw 275 based on the patient's anatomical structure, by which the region of interest can be defined. The center of the planned position of the screw 275 can be determined by enclosing the planned position of the screw 275 with a spherical virtual boundary having a diameter D equal to the length of the planned position of the screw 275 (e.g., represented by a line segment extending from one end of the planned position of the screw 275 to the other end of the planned position of the screw 275), and then treating the center of the spherical virtual boundary as the center of the planned position of the screw 275. The control system 141 can be configured to determine the planned screw 275 position for calculating the distance by enclosing a plurality of planned screw 275 positions with spherical virtual boundaries and then determining the distance between each of the drivers 240, 340, 440 and each of the spherical virtual boundaries. The control system 141 can then be configured to calculate the distance based on which distance is the shortest (i.e., which planned screw 275 position is closest to the tip of the drivers 240, 340, 440). Alternatively, the control system 141 can be configured to calculate the distance as a plurality of distances each corresponding to the distance between the tip of the drivers 240, 340, 440 and the center of any of the spherical virtual boundaries.

[0107] After calculating the distance between the tips of the drivers 240, 340, 440 and the center of the spherical virtual boundary, the radius R of the spherical virtual boundary can be subtracted from this distance. In this way, the distance is adjusted so that it becomes the distance between the tips of the drivers 240, 340, 440 and the outer boundary of the spherical virtual boundary, for example, at a position away from the region of interest. If the tips of the drivers 240, 340, 440 affect the virtual boundary, this adjusted distance may be desirable because an undesirable effect may be brought to the patient. Here too, since the control system 141 may not determine the direction along with the distance, the spherical virtual boundary can be used to minimize the possibility of such an undesirable effect. When the drivers 240, 340, 440 are approaching from above the position of the planned screw 275 to the position of the planned screw 275, the adjusted distance will match the distance between the upper part of the position of the planned screw 275 and the tips of the drivers 240, 340, 440. However, when the drivers 240, 340, 440 are approaching the position of the planned screw 275 from the side of the screw 275, the adjusted distance will match the distance obtained by adding the radius R to the distance between the drivers 240, 340, 440 and the center of the position of the planned screw 275. That is, the adjusted distance may be accurate when approaching from above the position of the planned screw 275. However, instead, it may be inaccurate when approaching from the side of the position of the planned screw 275. Since the calculation may lack a direction element, the control system 141 may not recognize whether the drivers 240, 340, 440 are approaching from above or the side of the planned screw 275. Therefore, it may be desirable to assume that the drivers 240, 340, 440 are located coaxially with the major axis of the position of the planned screw 275 and the drivers 240, 340, 440 are approaching from above the position of the planned screw 275. Furthermore, when the control system 141 is configured to monitor the distances between the tips of the drivers 240, 340, 440 and a plurality of positions of the planned screws 275, the above distance calculation is applicable to the plurality of distances.Since the drill bit may be used prior to the drivers 240, 340, 440, this method is also applicable when drill bits 240, 340, 440 are connected to the instruments 220, 320, 420 instead of the drivers 240, 340, 440.

[0108] In cases where there are multiple virtual boundaries for a particular patient, the control system 141 can perform distance calculations for all boundaries, or the control system 141 can perform calculations described only for the boundary closest to the instruments 220, 320, 420. More specifically, the control system 141 can determine the closest boundary based on the boundary closest to the current posture of the instruments 220, 320, 420. This determination may be based on the center of the planned screw 275 position and the closest point on the boundary mesh, or may use the center of the bars 240, 340, 440 and the closest point on the boundary mesh. The control system 141 is configured to switch boundaries in response to the user moving the instruments 220, 320, 420 to another aspect of the surgery, for example, when the user places a different screw 275, or when the user resections different levels of vertebrae. In other embodiments, the control system 141 can be configured to perform distance calculations only for the boundary closest to the anatomical structure defining the region of interest.

[0109] In a third example, the control system 141 can be configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455 based on both the duration of the occlusion event and the distance between the instruments 220, 320, 420 and the virtual boundary and / or region of interest prior to the occlusion event. The control system 141 can be configured to determine the duration threshold together with the distance threshold based on one or more other characteristics of the occlusion event regarding the combination of the duration threshold and the distance threshold, and to control the drive motors 245, 345, 445 and / or the alert modules 255, 355, 455. By considering both the duration and the distance associated with the occlusion event, the control system 141 can more accurately predict whether the occlusion event has an unacceptable level of uncertainty or causes such uncertainty. Thus, the control system 141 can be configured to ignore longer occlusion events when the surgical instruments 220, 320, 420 are far from the virtual boundary and / or region of interest. For example, if the instruments 220, 320, 420 were last observed at a position 2 meters from the virtual boundary, the control system 141 can ignore the occlusion event unless it lasts more than 10 seconds.

[0110] In the above combination example, the control system 141 may also be configured to set a duration threshold based on the distance between the instruments 220, 320, 420 and the region of interest and / or the virtual boundary, or to set a distance threshold based on the duration of the occlusion event. For example, when the instruments 220, 320, 420 approach the region of interest and / or the virtual boundary, the duration threshold may be decreased. Alternatively, when the instruments 220, 320, 420 move away from the region of interest and / or the virtual boundary, the duration threshold may be increased. Thereby, the control system 141 can determine whether to alert the surgeon and / or whether to control the drive motors 245, 345, 445 based on the potential risks associated with the occlusion event. For example, when the instruments 220, 320, 420 are relatively far from the region of interest and / or the virtual boundary, even if the instruments 220, 320, 420 are occluded from the field of view of the tracking unit 110 for a relatively long time, it may not be as important for the surgeon to recognize this as when the instruments 220, 320, 420 are relatively close to the region of interest and / or the virtual boundary. This is particularly true when the instruments 220, 320, 420 are not currently in use. The surgeon may temporarily leave the instruments 220, 320, 420 while performing other tasks, and the surgeon may not benefit from recognizing that an occlusion event is occurring for the instruments 220, 320, 420 that are not currently in use.

[0111] For example, as described above, the control system 141 is configured to determine the distance between the instruments 220, 320, 420 and the region of interest or a virtual boundary associated with the region of interest based on the tracked pose of the instruments in a known coordinate system with respect to a virtual boundary in the known coordinate system, and to determine whether the distance between the instrument and the region of interest or the virtual boundary exceeds a pre-determined threshold distance. If the threshold distance is exceeded, the control system 141 can be configured to set the duration threshold to a first pre-determined duration, and if not, the control system 141 can be configured to set the duration threshold to a second pre-determined duration that is less than the first pre-determined duration threshold. In this way, when the instruments 220, 320, 420 approach the region of interest or the associated virtual boundary, the control system 141 can be configured to shorten the minimum duration for which a shielding event needs to be present and take measures (e.g., control the drive motors 245, 345, 445 and / or the alert modules 255, 355, 455).

[0112] In some examples, a plurality of virtual boundaries are associated with a given region of interest, with the first of the virtual boundaries surrounding the region of interest and the second of the virtual boundaries, for example, located further from the region of interest than the first boundary according to a pre-determined distance from the first boundary. In this case, the control system 141 can be configured to determine whether the end effectors 240, 340, 440 of the surgical instruments 220, 320, 420 are between the first and second boundaries or outside the first and second boundaries in a known coordinate system, for example, using the ray casting method described above. If outside the boundaries, the control system 141 can be configured to set the duration threshold to a first pre-determined duration, and if between the boundaries, the control system 141 can be configured to set the duration threshold to a second pre-determined duration that is less than the first pre-determined duration threshold to achieve a similar effect as described above.

[0113] In some embodiments, the control system 141 is also configured to determine, for example, using the ray casting method described above, whether the end effectors 240, 340, 440 of the surgical instruments 220, 320, 420 are beyond a virtual boundary (e.g., the first virtual boundary described above) associated with the region of interest or are located within the region of interest. In that case, the control system 141 is configured to set the duration threshold to a different predetermined duration (e.g., a third predetermined duration) different from the predetermined duration (e.g., the second predetermined duration) for which the duration threshold is set when the end effectors 240, 340, 440 are outside the virtual boundary or the region of interest. In some cases, the different predetermined duration can be longer than the previous predetermined duration, and when the surgeon enters the region of interest or crosses a virtual boundary associated with the region of interest, it is possible that the surgeon is already on high alert and / or has received notification of a shielding event by other means (e.g., the LLA indicator 142), and it may be desirable to avoid confusing alerts or interruptions. For example, assuming the first and second predetermined durations described above, the third predetermined duration may exceed the second predetermined threshold and / or be equal to the first predetermined duration, corresponding to the surgical instruments 220, 320, 420 being relatively far from the region of interest.

[0114] In a fourth example, in response to an occlusion event, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 based on the direction of movement of instruments 220, 320, 420 (e.g., towards or away from the region of interest) relative to the region of interest prior to the occlusion event. The direction of movement can be determined based on the history of the pose of instruments 220, 320, 420 in a known coordinate system relative to a virtual boundary, as tracked by navigation system 100. This pose history may include a first pose of the instrument based on the tracked pose of instruments 220, 320, 420 relative to the virtual boundary at a first time prior to the occlusion event, and a second pose of the instrument based on the tracked pose of instruments 220, 320, 420 relative to the virtual boundary at a second time prior to the occlusion event. Control system 141 can be configured to calculate the direction of movement of instruments 220, 320, 420 by comparing the second pose to the first pose. More specifically, if the first pose indicates that instruments 220, 320, 420 (more specifically, end effectors 240, 340, 440) were at a position 10 mm from the virtual boundary, and the second pose indicates that instruments 220, 320, 420 (more specifically, end effectors 240, 340, 440) were at a position 5 mm from the virtual boundary, the control system can assume that instruments 220, 320, 420 were approaching the virtual boundary (and thus, the region of interest associated with the virtual boundary) when the occlusion event began. Since instruments 220, 320, 420 were approaching the virtual boundary / region of interest when the occlusion event began, it can be assumed that instruments 220, 320, 420 remain approaching the virtual boundary / region of interest during the occlusion event. Therefore, control system 141 can be configured to alert the surgeon and / or control the speed of drive motors 245, 345, 445 if instruments 220, 320, 420 were approaching the virtual boundary / region of interest when the occlusion event began.

[0115] On the other hand, the control system 141 may not alert the surgeon and / or may not control the drive motors 245, 345, 445 when the instruments 220, 320, 420 are moving away from the virtual boundary / region of interest when the occlusion event starts. For example, if the instruments 220, 320, 420 are at a position 5 mm from the virtual boundary in the first posture and at a position 10 mm from the virtual boundary in the second posture, it can be assumed that the instruments 220, 320, 420 are moving away from the virtual boundary / region of interest. Since the surgeon may move the tool away from the patient for any reason, it may be of relatively low value to alert the surgeon that the instruments 220, 320, 420 are blocked from view and / or to control the drive motors 245, 345, 445 of the instruments 220, 320, 420 that are not likely to be close enough to affect the region of interest.

[0116] In some embodiments, the control system 141 may be configured to scale a previously set duration threshold, which may be initially set based on the distance determined as described above, according to the direction of movement of the instruments 220, 320, 420 relative to the region of interest. For example, in response to a determination that the instruments 220, 320, 420 are approaching the virtual boundary / region of interest, the control console 141 may be configured to reduce the set duration threshold by a predefined scaling value, and in response to a determination that the instruments 220, 320, 420 are moving away from the virtual boundary / region of interest, to increase the set duration threshold by a predefined scaling value. In some examples, the magnitudes of the increase and decrease values can be equal. The control system 141 may then compare the scaled duration threshold to the duration of the occlusion event and be configured to determine whether to alert the surgeon and / or whether to control the drive motors 245, 345, 445 as described herein.

[0117] In a fifth example, in response to a shielding event, the control system 141 can be configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455 (e.g., immediately before the shielding event) based on the speeds of the appliances 220, 320, 420 associated with the shielding event. This speed can be determined (e.g., immediately before the shielding event) based on the history of the posture of the appliances 220, 320, 420 tracked by the navigation system 100 in a known coordinate system, based on the virtual boundaries of the appliances 220, 320, 420. The history of the posture may include the first and second postures of the appliances described in the fourth example above. However, when determining the output of the control system 141, not only the direction of movement of the appliances 220, 320, 420 may be considered, but also the speed of the appliances 220, 320, 420 may be considered. Therefore, the control system 141 can grasp how far the appliances 220, 320, 420 are considered to move during a shielding event of a certain length. For example, the control system 141 can be configured to determine that the appliances 220, 320, 420 are approaching the virtual boundary / region of interest based on a comparison of the second posture with the first posture. At this point, the control system 141 can also be configured to calculate the speed of the appliances 220, 320, 420 by dividing the difference between the second posture and the first posture by the difference between the second time point and the first time point. Thereby, in addition to the direction of the appliances 220, 320, 420, the speed of the appliances is also calculated.

[0118] When determining whether to control alert modules 255, 355, 455 and / or drive motors 245, 345, 445 in response to a shielding event, control system 141 can be configured to consider the speed of instruments 220, 320, 420 before or during the shielding event. Compared with instruments 220, 320, 420 moving at a low speed, instruments 220, 320, 420 approaching the virtual boundary / region of interest while moving at a high speed are more likely to unintentionally cross the virtual boundary and / or enter the region of interest associated with the virtual boundary during and / or before the shielding event than surgical instruments 220, 320, 420 approaching the virtual boundary / region of interest while moving at a low speed or surgical instruments 220, 320, 420 moving away from the virtual boundary / region of interest. Therefore, control system 141 can be configured to alert the surgeon before the shielding event or immediately after the shielding event occurs and / or control the speed of drive motors 245, 345, 445 in response to the speed of surgical instruments 220, 320, 420 indicating that the surgical instruments 220, 320, 420 are approaching the virtual boundary / region of interest at a speed exceeding a set threshold.

[0119] Additionally or alternatively, the control system 141 can be configured to take into account the speeds of the instruments 220, 320, 420 when determining the duration threshold for the aforementioned occlusion events. For example, if the instruments 220, 320, 420 are approaching the virtual boundary / region of interest at a relatively high speed (e.g., exceeding a predefined speed threshold), the control system 141 can be configured to set the duration threshold to a relatively short duration (e.g., 0.01 seconds) so as to alert the surgeon and / or control the drive motors 245, 345, 445 after a short occlusion event (e.g., 0.01 seconds). Conversely, if the instruments 220, 320, 420 are moving away from the virtual boundary / region of interest or approaching the virtual boundary / region of interest at a relatively low speed (e.g., below a predefined speed threshold), the control system 141 can be configured to set the duration threshold to a relatively long duration (e.g., 0.1 seconds) so as to alert the surgeon and / or control the drive motors 245, 345, 445 after a longer occlusion event (e.g., 0.1 seconds).

[0120] In some examples, if the speed indicates that the surgical instruments 220, 320, 420 are approaching the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a shorter duration than when the speed indicates movement away from the virtual boundary / region of interest. In some examples, the set duration may vary depending on the magnitude of the speed. For example, assuming the speed indicates movement towards the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a shorter duration as the speed increases, e.g., according to a linear function. Conversely, assuming the speed indicates movement away from the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a longer duration as the speed increases, e.g., according to a linear function.

[0121] In some embodiments, control system 141 can be configured to scale an initially set duration threshold based on the distance determined as described above according to the speeds of instruments 220, 320, 420. For example, in response to a determination that instruments 220, 320, 420 are approaching the virtual boundary / region of interest, control console 141 can reduce the set duration threshold by a predetermined scaling value, and in response to a determination that instruments 220, 320, 420 are moving away from the virtual boundary / region of interest, control console 141 can be configured to expand the set duration threshold by a predetermined scaling value. The magnitude of the values applied for expansion and reduction may be fixed, or alternatively, control system 141 may determine it based on the magnitude of the speeds of instruments 220, 320, 420. For example, the magnitude of the scaling value applied by control system 141 may increase as the speed increases, for example, according to a linear function, regardless of whether the duration threshold is about to be expanded or reduced. Next, control system 141 compares the scaled duration threshold with the duration of the occlusion event and is configured to determine whether to alert the surgeon and / or whether to control drive motors 245, 345, 445 as described herein.

[0122] In a sixth example, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 in response to a shielding event, based on the speeds of appliances 220, 320, 420 before the shielding event. The speed can be determined based on the history of the postures of appliances 220, 320, 420 tracked by navigation system 100. This posture history may include a first posture of the appliance based on the tracked posture of appliances 220, 320, 420 at a first time point before the shielding event, and a second posture of the appliance based on the posture of appliances 220, 320, 420 at a second time point before the shielding event. Unlike speed, since speed does not include a direction element, the first posture and the second posture do not need to be calculated with reference to a virtual boundary. Alternatively, the speeds of appliances 220, 320, 420 may be calculated by an inertial measurement unit (IMU) (not shown) attached to appliances 220, 320, 420.

[0123] Regardless of the method of calculating the speeds of appliances 220, 320, 420, control system 141 can then be configured to determine whether to control alert modules 255, 355, 455 and / or drive motors 245, 345, 445 in response to a shielding event, based on the speeds of appliances 220, 320, 420 before the shielding event begins. Similar to the example of speed, when appliances 220, 320, 420 are moving at a higher speed, they may inadvertently cross a virtual boundary and / or enter a region of interest associated with the virtual boundary. Thus, control system 141 can be configured to control alert modules 255, 355, 455 and / or drive motors 245, 345, 445 in response to the speeds of appliances 220, 320, 420 exceeding a predefined speed threshold.

[0124] Additionally or alternatively, the control system 141 can be configured to determine the aforementioned duration threshold based on the speed of the instruments 220, 320, 420. For example, if the instruments 220, 320, 420 were moving at a relatively low speed (e.g., below a predefined speed threshold) before the occlusion event, the control system 141 can be configured to set the duration threshold to a relatively long duration (e.g., 0.1 seconds) to alert the surgeon and / or control the drive motors 245, 345, 445 after a longer (e.g., 0.1 second) occlusion event. However, if the instruments 220, 320, 420 were moving at a relatively high speed (e.g., above a predefined speed threshold) before the occlusion event, the control system 141 can be configured to set the duration threshold to a relatively short duration (e.g., 0.01 seconds) to alert the surgeon and / or control the drive motors 245, 345, 445 after a short (e.g., 0.01 second) occlusion event. In some examples, the duration threshold can be set to a fixed relatively long duration and a short duration depending on whether the speed is below or above a predefined speed threshold. Alternatively, the duration threshold to be set can be set according to a function that defines a shorter duration as a function of increasing speed, for example, according to a linear relationship.

[0125] In some embodiments, control system 141 can be configured to scale an initially set duration threshold based on the distance determined as described above according to the speeds of instruments 220, 320, 420. For example, control system 141 can be configured to reduce the duration threshold based on the speeds of instruments 220, 320, 420 such that the scaling value applied to the duration threshold increases as the speed increases. Alternatively, control system 141 can be configured to expand and reduce the duration threshold based on the speeds of instruments 220, 320, 420 in response to a determination that the speed exceeds a threshold speed, where the duration threshold is reduced according to a scaling value, which can be of a fixed magnitude or a variable magnitude based on the degree of speed. Conversely, in response to a determination that the speed is below the threshold speed, the duration threshold can be expanded according to a scaling value, which can be of a fixed magnitude or a variable magnitude based on the degree of speed. Control system 141 then can be configured to compare the scaled duration threshold to the duration of the occlusion event and determine whether to alert the surgeon and / or control drive motors 245, 345, 445 as described herein.

[0126] In a seventh example, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 based on the acceleration of appliances 220, 320, 420 associated with a shielding event in response to the shielding event. Similar to the directions, velocities, and speeds of appliances 220, 320, 420 described above, control system 141 can be configured to determine acceleration based on the posture history of appliances 220, 320, 420 tracked by navigation system 100. However, this acceleration can be calculated based on at least a first posture, a second posture, and a third posture of appliances 220, 320, 420. The third posture of appliances 220, 320, 420 may be based on the tracked posture of appliances 220, 320, 420 at a third point in time before the shielding event. The first posture, the second posture, and the third posture may be determined based on a virtual boundary or may be determined without reference to a virtual boundary. To determine the acceleration, a first velocity or a first speed is calculated based on the difference between the second posture and the first posture. After the first velocity or the first speed is calculated, a second velocity or a second speed is calculated based on the difference between the third posture and the second posture. Finally, the acceleration is calculated based on either the difference between the second velocity and the first velocity or the difference between the second speed and the first speed. Using velocity, control system 141 can determine the directional component of the acceleration. However, this may increase the computational cost, so speed may be used instead. Alternatively, the acceleration of appliances 220, 320, 420 may be calculated by an inertial measurement unit (IMU) attached to appliances 220, 320, 420.

[0127] Regardless of the method for calculating the accelerations of appliances 220, 320, and 420, control system 141 is then configured to determine whether to control alert modules 255, 355, and 455 and / or whether to control drive motors 245, 345, and 445 based on the accelerations of appliances 220, 320, and 420 before the start of the shielding event in response to the shielding event. Similar to the examples of speed and velocity, appliances 220, 320, and 420 may be likely to cross an unintended virtual boundary and / or enter a region of interest associated with the virtual boundary when having a greater acceleration. Thus, control system 141 is configured to control alert modules 255, 355, and 455 and / or drive motors 245, 345, and 445 in response to appliances 220, 320, and 420 having a relatively large acceleration before the shielding event, as indicated by, for example, the acceleration exceeding a predefined acceleration threshold. Further, since the acceleration is calculated using the first speed, the second speed, and the third speed, if a direction component is included, the direction component of the acceleration may be considered by control system 141. For example, control system 141 can be configured to determine whether appliances 220, 320, and 420 were accelerating toward the virtual boundary / region of interest before the shielding event. If accelerating, control system 141 is configured to control alert modules 255, 355, and 455 and / or drive motors 245, 345, and 445 in response to appliances 220, 320, and 420 having a relatively large acceleration before the shielding event, as indicated by, for example, the acceleration exceeding a predefined acceleration threshold. If not accelerating, control system 141 can be configured to allow the continuation of the shielding event based on the assumption that appliances 220, 320, and 420 are moving away from the patient without performing such control.

[0128] Additionally or alternatively, the control system 141 can be configured to determine the aforementioned duration threshold based on the acceleration of the instruments 220, 320, 420. For example, if the acceleration is relatively small and in the direction towards the virtual boundary / region of interest, or if the acceleration is in the direction away from the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a relatively long duration (e.g., 0.1 seconds) so as to alert the surgeon and / or control the drive motors 245, 345, 445 after a longer (e.g., 0.1 seconds) occlusion event. Conversely, if the acceleration is relatively large and in the direction towards the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a relatively short duration (e.g., 0.01 seconds) so as to alert the surgeon and / or control the drive motors 245, 345, 445 after a short (e.g., 0.01 seconds) occlusion event.

[0129] In some examples, if the acceleration indicates that the surgical instruments 220, 320, 420 are accelerating towards the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a shorter duration than when the acceleration indicates that the instruments are moving away from the virtual boundary / region of interest. In some examples, the duration set for the duration threshold may vary depending on the magnitude of the acceleration. For example, assuming that the acceleration indicates movement towards the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a shorter duration as the magnitude of the acceleration increases, for example, according to a linear function. Conversely, assuming that the acceleration indicates movement away from the virtual boundary / region of interest, the control system 141 can be configured to set the duration threshold to a longer duration as the magnitude of the acceleration increases, for example, according to a linear function.

[0130] In some embodiments, the control system 141 can be configured to scale a duration threshold that may be initially set based on the distance determined as described above, according to the accelerations of the instruments 220, 320, 420. For example, in response to a determination that the instruments 220, 320, 420 are accelerating toward the virtual boundary / region of interest, the control console 141 can reduce the set duration threshold by a predetermined scaling value, and in response to a determination that the instruments 220, 320, 420 are accelerating away from the virtual boundary / region of interest, the control console 141 can be configured to increase the set duration threshold by a predetermined scaling value. The magnitude of the values applied for the increase and decrease may be fixed or may vary based on the magnitude of the acceleration of the instruments 220, 320, 420. For example, the magnitude of the scaling value applied by the control system 141 may increase as the magnitude of the acceleration increases, according to, for example, a linear function, regardless of whether the duration threshold is about to be increased or decreased. The control system 141 then compares the scaled duration threshold to the duration of the occlusion event and can be configured to determine whether to alert the surgeon and / or whether to control the drive motors 245, 345, 445 as described herein.

[0131] In some embodiments, whether the velocity, speed, acceleration associated with the occlusion event is used to determine the duration threshold may be based on the type of the currently operating end effectors 240, 340, 440 or the type of the surgical instruments 220, 320, 420. To that end, the control system 141 can be configured to determine the type of the operating surgical instruments 220, 320, 420 or the type of the end effectors 240, 340, 440, and this type may be indicated by the user's input. As an example, in response to a determination that the type of the end effectors 240, 340, 440 is a driver, the control system 141 can be configured to determine (e.g., scale) the duration threshold based on the velocity of the surgical instruments 220, 320, 420 associated with the occlusion event as described above. Conversely, in response to a determination that the type of the end effectors 240, 340, 440 is a bar, the control system 141 can be configured to determine (e.g., scale) the duration threshold based on the speed of the surgical instruments 220, 320, 420 associated with the occlusion event as described above.

[0132] In the eighth example, in response to a shielding event, the control system 141 can be configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455 based on the motion parameters of the instruments 220, 320, 420 before the shielding event. The motion parameters can be determined based on at least one of the direction, velocity, speed, and / or acceleration of the instruments 220, 320, 420. The direction, velocity, speed, and / or acceleration of the instruments 220, 320, 420 can be determined as described above. Further, the surgeon can have the option to select specific parameters included in the motion parameters. For example, the graphical user interface 150 may include selection means by which the surgeon can instruct the control system 141 to consider the specified parameters when determining an appropriate response to the shielding event. This selection means can be a drop-down menu, a series of radio buttons, a series of check boxes, or any suitable alternative means.

[0133] In a ninth example, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 based on a shielding event associated with patient tracking device PT. Since the patient is mostly stationary during most medical procedures, control system 141 can be configured to determine the duration of the shielding event and respond as in the first example. For example, control system 141 can be configured to determine a duration threshold and to ignore any shielding event if the duration of the shielding event is shorter than the duration threshold. Further, control system 141 can be configured to control at least one of drive motors 245, 345, 445 and alert modules 255, 355, 455 based on characteristics of a shielding event associated with patient tracking device PT, where the characteristics can include one or more characteristics of the shielding event itself and / or the instruments 220, 320, 420 associated with the shielding event (e.g., during and / or prior to shielding of patient tracking device PT). More specifically, control system 141 can be configured to determine the posture of surgical instruments 220, 320, 420 during and / or prior to a shielding event, the distance between instruments 220, 320, 420 and a virtual boundary / region of interest during and / or prior to a shielding event, the speed of instruments 220, 320, 420 during and / or prior to a shielding event, the acceleration of instruments 220, 320, 420 during and / or prior to a shielding event, and / or the motion parameters of instruments 220, 320, 420 during and / or prior to shielding of patient tracking device PT. The above characteristics of instruments 220, 320, 420 can be calculated and used as described in the above examples. For example, control system 141 can be configured to determine a duration threshold for a shielding event associated with patient tracking device PT based on the distance between instruments 220, 320, 420 and a virtual boundary / region of interest during and / or prior to the shielding event.The duration threshold can be set to a shorter duration when the appliances 220, 320, 420 approach the virtual boundary / region of interest than when the appliances 220, 320, 420 are away from the virtual boundary / region of interest. Similar combination examples are also contemplated.

[0134] Furthermore, it is also contemplated to combine the above examples in any combination. For example, the control system 141 can be configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455 based on the duration of the shielding event, the motion parameters of the appliances 220, 320, 420, and the distance between the appliances 220, 320, 420 and the virtual boundary. Other combinations are also contemplated.

[0135] Furthermore, the control system 141 can control an LLA indicator 142 configured to notify a surgeon of the occurrence of a shielding event. Generally, the LLA indicator 142 may include a visually perceivable device, such as an LED or a visual display, which is activated by the control system 141 when a shielding event is detected. The LLA indicator 142 may be incorporated such that the surgeon can recognize a shielding event, which may be considered irrelevant or unimportant in other respects according to the above examples. For example, assume that the control system 141 is configured to control at least one of the drive motors 245, 345, 445 and the alert modules 255, 355, 455 based on the distance between the instruments 220, 320, 420 and the virtual boundary during and / or before the shielding event in response to the shielding event. Such control may not occur if the instruments 220, 320, 420 are far away from the patient. However, in the same example, the LLA indicator 142 may be activated even when the drive motors 245, 345, 445 and the alert modules 255, 355, 455 are not actively controlled by the control system 141. Thus, the LLA indicator 142 can suggest to the surgeon to bring the instruments 220, 320, 420 into the field of view of the tracking unit 110 before the surgeon engages with the patient using the instruments 220, 320, 420.

[0136] Referring to FIG. 6, an exemplary configuration of a surgical system including the above-described surgical navigation system 100 and a first surgical instrument 220 is illustrated. In FIG. 6, only the first surgical instrument is shown, but it is contemplated that any of the surgical instruments 220, 320, 420 described above may be included in the system. The surgical system may also have a plurality of end effectors 240A, 240B, 240C detachably connectable to the handpiece 225 of the first surgical instrument 220. The end effectors 240A, 240B, 240C may also be referred to as end effectors, surgical attachments, and / or tool attachments. For example, the surgical system may have a first end effector 240A incorporating a drill for cutting and / or making holes in biological material. The surgical system may further have a second end effector 240B incorporating a tap for forming threads on the inner surface of a hole or opening. Additionally, the surgical system may also have a third end effector 240C incorporating a driver for driving or inserting a screw into a hole or opening. Each of the end effectors 240A, 240B, 240C may include instrument tracking devices 230A, 230B, 230C incorporating markers 235A, 235B, 235C of unique configurations and / or arrangements. The navigation system 100 is configured to identify the end effectors 240A, 240B, 240C based on the known association with a particular handpiece 225 and the unique sizes, shapes, and / or arrangements of the markers 235A, 235B, 235C of the instrument tracking devices 230A, 230B, 230C attached to that particular handpiece 225. Next, the navigation system can be configured to provide virtual boundaries (boundaries 1, 2, 3, 4) and / or alert zones (zones 1, 2, 3, 4) to the appropriate end effectors 240A, 240B, 240C being currently navigated. An exemplary method of navigating an instrument based on the fact that a particular instrument is being navigated with respect to virtual boundaries, alert zones, target trajectories, and / or target depths is described in International Patent Publication No. WO 2021 / 062373, the entire disclosure of which is incorporated herein by reference.

[0137] Referring to FIG. 7, an exemplary configuration of a surgical system including the above-described surgical navigation system 100 and a second surgical instrument 320 is illustrated. In FIG. 7, only the second surgical instrument 320 is illustrated, but it is contemplated that any of the above-described surgical instruments 220, 320, 420 may be included in the system. Further, the surgical system can also have a plurality of end effectors 340A, 340B, 340C that are detachably coupled to the handpiece 325 of the second surgical instrument 320. The end effectors 340A, 340B, 340C may also be referred to as end effectors, surgical attachments, and / or tool attachments. For example, the surgical system can have a first end effector 340A that includes a first bar head 360A having a first diameter head D1. The surgical system can further have a second end effector 340B that includes a second bar head 360B having a second diameter head D2. Additionally, the surgical system can also have a third end effector 340C that includes a third bar head 360C having a third diameter head D3. And it is contemplated that the heads of each of the end effectors 340A, 340B, 340C may differ by shape, material, and / or cutting type. Further, it is also contemplated that the length of the shaft may vary from one end effector 340A, 340B, 340C to the next end effector. The surgical navigation system 100 can be configured to identify which of the end effectors 340A, 340B, 340C is connected to the handpiece 325 in a manner similar to that described above with respect to the end effectors 240A, 240B, 240C. The navigation system can then be configured to provide virtual boundaries (boundaries 1, 2, 3, 4) and / or alert zones (zones 1, 2, 3, 4) to the appropriate end effectors 340A, 340B, 340C that are currently being navigated. An exemplary method of navigating an instrument based on which particular instrument is being navigated with respect to virtual boundaries, alert zones, target trajectories, and / or target depths is described in International Patent Publication No. WO 2021 / 062373, the entire contents of which are incorporated herein by reference.

[0138] Referring to FIG. 8, an exemplary configuration of the graphical user interface (GUI) 150 of the navigation system 100 is illustrated. The graphical user interface (GUI) 150 can be configured as a touch screen on the display unit 120 of the navigation system 100. As shown in FIG. 8, the graphical user interface (GUI) 150 can have a plurality of buttons and / or prompts that are selectable and / or operable by the surgeon. For example, the graphical user interface (GUI) 150 can have an exemplary alert setting interface 151 or window that includes a plurality of buttons that are selectable or operable by the user to modify or adjust various settings for alerts to be provided during a medical procedure. The alert setting interface 151 can have at least one tool selection button 152. The tool selection button(s) 152 can enable the surgeon to select the surgical instrument assemblies 200, 300, 400 from a pre-entered list of surgical instruments, or can enable the surgeon to enter a particular surgical instrument assembly 200, 300, 400 to be utilized during the performance of a surgical procedure. For example, the tool selection button 152 can enable the surgeon to select the second surgical instrument 320 that includes a high-speed cutting bar. Thereby, since a particular surgical instrument 320 is identified from the navigation system 100, the navigation system 100 can input various virtual boundaries and / or alert zones used for the identified instrument. Further, the tool selection button(s) 152 can be configured such that the surgeon can select the end effectors 240, 340, 440 that can be coupled to the surgical instruments 220, 320, 420. The alert setting interface 151 can further have one or more alert buttons 156. The alert buttons 156 can be used to operate the various alerts described above. For example, the alert buttons 156 can be configured such that the user can activate or deactivate alerts related to the rotational speed of the end effectors 240, 340, 440, tactile alerts, visual alerts, and / or audible alerts.

[0139] The alert setting interface 151 of the graphical user interface (GUI) 150 can also have one or more alert graphics 158A, 158B. The alert graphic(s) 158A, 158B are specific to the particular surgical instruments 220, 320, 420 and / or end effectors 240, 340, 440 selected via the GUI 150, and may be configured to provide a schematic and / or visual representation of the positions of various virtual boundaries and / or alert zones. The first alert graphic 158A can have a visual representation of the surgical site, the region of interest at the surgical site, and any implant or device to be inserted during the medical procedure to assist the surgeon in identifying the location of the surgery and in setting various alerts. For example, as shown in FIG. 8, the first alert graphic 158A includes a visual representation of a vertebral body schematically indicating the region where the surgery is to be performed with a dotted line. The first alert graphic may further include a visual representation of the pedicle screw to be inserted during the surgery.

[0140] To facilitate adjustment or modification of where the alerts assigned by the surgeon to each of the various virtual boundaries and / or alert zones should be triggered, the second alert graphic 158B can be configured to provide a visual representation of the implant or device to be inserted during the surgery, along with markers indicating the various virtual boundaries (boundaries 1, 2, 3, 4) for the implant or device. For example, as shown in FIG. 8, the second alert graphic 158B includes a visual representation of the pedicle screw to be inserted and markers along the pedicle screw indicating the positions of the various virtual boundaries (boundaries 1, 2, 3, 4) for the pedicle screw that trigger various alerts during the surgery.

[0141] The alert setting interface 151 of the graphical user interface (GUI) 150 may also include one or more virtual boundary setting interfaces 160A, 160B. The boundary setting interfaces 160A, 160B may include one or more prompts or buttons 162 for setting virtual boundaries and / or for manipulating the timing at which virtual boundaries, alert zones, and / or target depths trigger one or more of the various alerts described above. Thereby, the navigation system 100 can determine how many virtual boundaries, alert zones, and / or target depths to provide. For example, when a surgeon operates a first button 162 indicating that a laminectomy is to be performed, the navigation system 100 recognizes that this is an excision process, and the navigation system 100 also identifies important structures of the vertebrae and recognizes that it provides various alert zones around them to assist the surgeon during the operation.

[0142] International Patent Publication No. 2021 / 062373 describes an exemplary graphical user interface, the entirety of which is incorporated herein by reference.

[0143] Referring to FIG. 9, an exemplary graphical user interface (GUI) 150 including a shielding event button 170 and a shielding event interface 172 is shown. The shielding event button 170 is configured to present the shielding event interface 172 to the user, and the shielding event interface 172 is configured to enable the user to set the control system 141. More specifically, the shielding event interface 172 can include selection means by which the user can select the characteristics of the shielding event considered by the control system 141. Depending on the selected characteristics, the control system 141 can control the alert modules 255, 355, 455 and / or the drive motors 245, 345, 445 of the surgical instruments 220, 320, 420 in response to the shielding event based on the selected characteristics. The shielding event interface 172 can also enable the user to set the control system 141 and control the alert modules 255, 355, 455 and / or the drive motors 245, 345, 445 based on the shielding of the patient tracking device PT.

[0144] The occlusion event interface 172 may be used by a user to configure the control system 141 based on which medical procedure is being performed and / or which surgeon is performing the surgery to meet the needs and / or wishes of the surgeon. Specifically, the occlusion event interface 172 can include selection means for selecting at least one of the following characteristics. The characteristics include the cause of the occlusion event, the duration of the occlusion event, the postures of the surgical instruments 220, 320, 420 (e.g., postures based on a virtual boundary / region of interest), the distances between the instruments 220, 320, 420 and the virtual boundary / region of interest, the speeds of the instruments 220, 320, 420, the velocities of the instruments 220, 320, 420, the accelerations of the instruments 220, 320, 420, and / or the motion parameters of the instruments 220, 320, 420 during and / or before the occlusion event. Other characteristics are contemplated, including some of those included above and those not listed herein. For example, a surgeon may wish for the control system 141 to control the alert modules 255, 355, 455 and / or drive motors 245, 345, 445 of the surgical instruments 220, 320, 420 in response to any occlusion event lasting longer than 0.1 seconds. In such an example, the occlusion event interface 172 may include time selection means for selecting a duration threshold. Further, the occlusion event interface 172 may include alert selection means by which the user / surgeon can select how the control system 141 is to control the alert modules 255, 355, 455 and / or drive motors 245, 345, 445 of the surgical instruments 220, 320, 420 in response to an occlusion event exceeding the selected duration threshold. For example, a surgeon may wish for the control system 141 to use the alert modules 255, 355, 455 to issue an audible alert and decelerate the drive motors 245, 345, 445 in response to an occlusion event.

[0145] The occlusion event interface 172 may also include a button (not shown) configured to switch the occlusion detection mode of the control system 141 between an active state and an inactive state.

[0146] Referring still to FIG. 9, an exemplary Location Loss of Awareness (LLA) indicator 142 is also shown. As previously described, the LLA indicator 142 can include a software routine with instructions stored in a memory, to which the control system 141, the surgical navigation system 100, one or more of the surgical instrument assemblies 200, 300, 400, and / or other elements of the surgical system 10 are accessible. The LLA indicator 142 is configured to provide an indication of an ongoing occlusion event. As can be seen from FIG. 9, the LLA indicator 142 can be implemented as a small window separate from the GUI 150. In the example shown, the LLA indicator 142 is small so as not to overspread the GUI 150 and is offset from the center of the screen. Generally, the LLA indicator 142 includes an indication of whether an occlusion event has been detected. For example, the LLA indicator 142 can be a plain box that switches between two colors to indicate whether an occlusion event has been detected. In such an example, the LLA indicator 142 can be a green box when no occlusion event has been detected, and the LLA indicator 142 can change to a red box in response to the detection of an occlusion event. In another example, the LLA indicator 142 can be a pop-up screen that appears only when an occlusion event has been detected. Other examples are contemplated.

[0147] The LLA indicator 142 may further incorporate means for changing the operation of the LLA indicator 142. In one example, the LLA indicator 142 may include a button configured to switch the LLA indicator 142 between an active state in which the LLA indicator 142 indicates the occurrence of a shielding event and an inactive state in which the LLA indicator 142 does not indicate the occurrence of a shielding event. In another example, the LLA indicator 142 may include a snooze button configured to disable the LLA indicator 142 for a predefined period. In another example, the LLA indicator 142 may incorporate selection means configured to change how the LLA indicator 142 is displayed on the GUI 150. For example, by this selection means, the user may be able to cause the LLA indicator 142 to be displayed on the GUI 150 as at least one of a pop-up, a fixed box including a color display, and other suitable alternative means. In another example, by this selection means, the user may be able to change the size and / or position of the LLA indicator 142 displayed on the GUI 150. Combinations of examples are also contemplated.

[0148] The broad teachings of the present 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 orders (or concurrently) without altering the principles of the present disclosure. Further, while each example is described above as having certain features, any one or more of the features described with respect to any example of the present disclosure may be implemented in and / or combined with any of the features of any other example, even if the combination is not explicitly described, i.e., the described examples are not mutually exclusive, and substitutions of one or more examples with each other remain within the scope of the present disclosure.

[0149] Spatial and functional relationships between elements (e.g., between a controller, 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 stated to be "direct", when a relationship between a first element and a second element is described in the above disclosure, the relationship can be a direct relationship with no other intervening elements between the first element and the second element, but can also be an indirect relationship with one or more intervening elements (spatially or functionally) between the first element and the second element.

[0150] As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean the logic (A OR B OR C) using non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C". The term subset does not necessarily require a proper subset. In other words, the first subset of the first set may refer to (be equal to) the same object as the first set.

[0151] In the figures, the direction of the arrow generally indicates the flow of the information (data or instructions, etc.) being illustrated, as indicated by the arrowhead. For example, if element A and element B exchange various information and the information transmitted from element A to element B is relevant to the figure, the arrow may point from element A to element B. This one-way arrow does not mean that no other information is transmitted from element B to element A. Further, with respect to the information transmitted from element A to element B, element B can transmit a request for information or an acknowledgment of receipt to element A.

[0152] In this application, which includes the following definitions, the terms "controller" or "module" can be replaced with the term "circuit". The term "controller" refers to an application-specific integrated circuit (ASIC), a programmable system-on-chip (PSoC), a digital, analog, or hybrid analog / digital discrete circuit, a digital, analog, or hybrid analog / digital integrated circuit, a combinational logic circuit, a field-programmable gate array (FPGA), a processor circuit (shared, dedicated, or grouped) that executes code, a memory circuit (shared, dedicated, or grouped) that stores code executed by the processor circuit, other suitable hardware components that provide the described functionality, or some or all combinations of the above in a system-on-chip, etc., or a part thereof, or may include it.

[0153] The controller may include one or more interface circuits with one or more transceivers. In some examples, the interface circuit(s) may implement a wired or wireless interface to connect to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs are the Institute of Electrical and Electronics Engineers (IEEE) standards 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 WPANs are the BLUETOOTH wireless networking standard of the Bluetooth Special Interest Group and IEEE standard 802.15.4.

[0154] The controller can communicate with other controllers using an interface circuit (which may be plural). Although the controller may be depicted in this disclosure as communicating logically directly with other controllers, in various embodiments, the controller may actually communicate via a communication system. The communication system may include physical and / or virtual networking devices such as hubs, switches, routers, gateways, and transceivers. In some embodiments, the communication system connects to or traverses a wide area network (WAN) such as the Internet. For example, the communication system may include multiple LANs connected to each other via the Internet or a point-to-point dedicated line using technologies including Multiprotocol Label Switching (MPLS) and Virtual Private Network (VPN).

[0155] In various embodiments, the functions of the controller may be distributed among multiple controllers connected via a communication system. For example, multiple controllers may implement the same function distributed by a load balancing system. In a further example, the functions of the controller can be split between a server (also known as remote or cloud) controller and a client (or user) controller.

[0156] Some or all of the hardware functions of the controller can be defined using languages for hardware description, such as IEEE standard 1364 - 2005 (generally referred to as "Verilog") and IEEE standard 1076 - 2008 (generally referred to as "VHDL"). Hardware description languages can be used to manufacture and / or program hardware circuits. In some embodiments, some or all of the features of the controller can be defined by languages such as IEEE 1666 - 2005 (generally referred to as "SystemC") that include both the code and hardware description described below.

[0157] The term "code" as used above can include software, firmware, and / or microcode, and may refer to a program, routine, function, class, data structure, and / or object. The term "shared processor circuit" encompasses a single processor circuit that executes some or all of the code from multiple controllers. The term "group processor circuit" encompasses a processor circuit that, in combination with additional processor circuits, executes some or all of the code from one or more controllers. References to multiple processor circuits include multiple processor circuits on separate dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or combinations of the above. The term "shared memory circuit" encompasses a single memory circuit that stores some or all of the code from multiple controllers. The term "group memory circuit" encompasses a memory circuit that, in combination with additional memory, stores some or all of the code from one or more controllers.

[0158] The term "memory circuit" is a subset of the term "computer-readable medium". The term "computer-readable medium", as used herein, does not include transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave). Thus, the term "computer-readable medium" can be considered tangible and non-transitory. Non-limiting examples of non-transitory computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray (registered trademark) discs).

[0159] The apparatus and methods described in this application can be implemented, in part or in whole, by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks and flowchart elements described above can function as software specifications and can be converted into a computer program by routine work of a skilled surgeon or programmer.

[0160] The computer program includes processor-executable instructions stored on at least one non-transitory computer-readable medium. The computer program may also include or depend on stored data. The computer program can include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, and the like.

[0161] As a computer program, examples can include (i) parsed descriptive text 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, and the like. By way of example only, source code can be described 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 5th revision), Ada, ASP (Active Server Pages), PHP (Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash™, Visual Basic™, Lua, MATLAB®, SIMULINK®, and Python™.

[0162] Some examples are described with respect to the following numbered items, with specific features being explained in the dependent items. [Item 1] A method for determining a shielding event for a tracking device coupled to a handheld instrument incorporating a drive motor, the method comprising: tracking the tracking device coupled to the handheld instrument using a tracking unit; determining an attitude of the instrument; determining a boundary; determining whether the shielding event has occurred for the tracking device; controlling at least one of the alert module and the drive motor based on the shielding event, the boundary, and the attitude of the instrument. A method comprising [Item 2] A navigation system for tracking a tracking device connected to a hand-held instrument incorporating a drive motor, a tracking unit, an alert module, a control system communicating with the tracking unit and the alert module, determining the orientation of the instrument, determining a boundary, controlling the alert module based on the boundary and the orientation of the instrument, determining that an occlusion event has occurred on the tracking device, and a control system configured to control the drive motor based on the occlusion event, the boundary, and the orientation of the instrument, A navigation system comprising [Item 3] A method for determining an occlusion event for a tracking device connected to a hand-held instrument incorporating a drive motor, tracking the orientation of the instrument in a known coordinate system using a tracking unit; determining a boundary in the known coordinate system associated with a region of interest of a surgical procedure; controlling the alert module based on the boundary and the tracked orientation of the instrument in the known coordinate system; determining that an occlusion event has occurred on the tracking device; and controlling the drive motor based on the occlusion event, the boundary, and the tracked orientation of the instrument. A method comprising [Item 4] A navigation system configured to be held in a user's hand for tracking an instrument including a drive motor, a tracking unit configured to generate tracking data indicative of the orientation of the instrument in a known coordinate system in cooperation with a tracking device connected to the instrument A tracking unit, an alert module for indicating the position of the instrument relative to the region of interest of the surgical operation, and a control system for communicating with the instrument, tracking the posture of the instrument in the known coordinate system based on the tracking data, determining a boundary in the known coordinate system that is associated with the region of interest, controlling the alert module based on the boundary and the tracked posture of the instrument in the known coordinate system, determining that a shielding event has occurred in the tracking device, determining the duration of the shielding event, a control system configured to control the drive motor based on the duration of the shielding event, A navigation system comprising the same. [Item 5] The control system is determining a duration threshold based on one or more characteristics of the shielding event, The navigation system according to item 4, configured to control the drive motor based on the duration of the shielding event and the duration threshold. [Item 6] A method for determining a shielding event for a tracking device connected to a handheld instrument incorporating a drive motor, comprising: tracking the posture of the instrument in a known coordinate system using a tracking unit; determining a boundary in the known coordinate system that is associated with the region of interest of the surgical operation; controlling the alert module based on the boundary and the tracked posture of the instrument in the known coordinate system; determining that a shielding event has occurred in the tracking device; determining the distance between the instrument and the region of interest based on the boundary and the tracked posture of the instrument in the known coordinate system; Controlling the drive motor based on the distance between the instrument and the region of interest and the occlusion event; A method comprising. [Item 7] A method for determining an occlusion event for a tracking device coupled to a handheld instrument incorporating a drive motor, comprising: Tracking the orientation of the instrument in a known coordinate system using a tracking unit; Determining a boundary in the known coordinate system associated with a region of interest of a surgical procedure; Controlling the alert module based on the boundary and the tracked orientation of the instrument in the known coordinate system; Determining that an occlusion event has occurred in the tracking device; Determining the duration of the occlusion event; Determining the distance between the instrument and the region of interest based on the boundary and the tracked orientation of the instrument in the known coordinate system; Controlling the alert module based on the duration of the occlusion event and the distance between the instrument and the region of interest; A method comprising. [Item 8] A handheld surgical system comprising: An instrument configured to be held by a user's hand and incorporating a drive motor; A console coupled to the instrument; A tracking device coupled to the instrument; A tracking unit; An alert module; A control system in communication with the tracking unit, the alert module, and the console, the control system being configured to: Determine the orientation of the instrument; Determine a boundary; Control the alert module based on the boundary and the orientation of the instrument; Determine that an occlusion event has occurred in the tracking device; A control system configured to control the drive motor based on the occlusion event, the boundary, and the posture of the instrument. A handheld surgical system comprising the same. [Item 9] The control system further determines the duration of the occlusion event, The handheld surgical system according to item 8, configured to control the drive motor based on the duration of the occlusion event. [Item 10] The control system further determines the distance between the instrument and the boundary based on the boundary and the posture of the instrument, The handheld surgical system according to item 8 or 9, configured to control the drive motor based on the distance and the occlusion event. [Item 11] The control system further determines the duration of the occlusion event, determines the distance between the instrument and the boundary based on the boundary and the posture of the instrument, The handheld surgical system according to any one of items 8 to 10, configured to control the drive motor based on the duration, the distance, and the occlusion event. [Item 12] The handheld surgical system according to any one of items 8 to 11, wherein the alert module is a vibratory foot switch, a graphical user interface, or a speaker. [Item 13] The handheld surgical system according to any one of items 8 to 12, wherein the alert module is defined as a software routine. [Item 14] The handheld surgical system according to item 13, wherein the software routine is configured to set the driving speed of the motor. [Item 15] The handheld surgical system according to item 13, wherein the software routine is configured to stop the drive motor. [Item 16] The system further comprises a switch that communicates with the instrument and the control system, the switch being configured to generate an input signal sufficient to control the instrument. The handheld surgical system according to any one of items 8 to 15, wherein the control system is further configured to restart the drive motor based on the input signal. [Item 17] The control system further determines the duration of the occlusion event, determines a duration threshold, The handheld surgical system according to any one of items 8 to 16, wherein the control system is configured to control the alert module based on the duration and the duration threshold. [Item 18] The system further comprises a switch that communicates with the instrument and the control system, the switch being configured to generate an input signal sufficient to control the instrument, the handheld surgical system according to any one of items 8 to 17. [Item 19] The control system is further configured to determine the duration of the occlusion event and to determine the distance between the instrument and the boundary. The control of the alert module based on the boundary and the posture of the instrument further includes the control of the alert module based on the duration and the distance of the occlusion event, the handheld surgical system according to any one of items 8 to 18. [Item 20] The control system further determines the direction of movement of the instrument based on the posture of the instrument and the boundary, The handheld surgical system according to any one of items 8 to 19, wherein the control system is configured to control the drive motor based on the direction of movement of the instrument and the occlusion event. [Item 21] The control system further determines a first posture of the instrument based on the posture of the instrument at a first point in time, determines a second posture of the instrument based on the posture of the instrument at a second point in time, and is configured to determine the direction of the instrument based on the first posture of the instrument and the second posture of the instrument. The handheld surgical system according to item 20. [Item 22] The instrument further includes a battery that communicates electrically with the drive motor, and control of the drive motor includes control of the battery. The handheld surgical system according to any one of items 8 to 21. [Item 23] The control system further determines the speed of the instrument based on the boundary and the posture of the instrument, and is configured to control the drive motor based on the speed of the instrument. The handheld surgical system according to any one of items 8 to 22. [Item 24] The control system further determines a first posture of the instrument based on the posture of the instrument at a first point in time, determines a second posture of the instrument based on the posture of the instrument at a second point in time, and is configured to determine the speed of the instrument based on the first posture of the instrument and the second posture of the instrument. The handheld surgical system according to item 23. [Item 25] The control system further is configured to determine the motion parameters of the instrument based on the posture and boundary of the instrument. The handheld surgical system according to any one of items 8 to 24. [Item 26] The motion parameters are selected from at least one of the direction of the instrument, the speed of the instrument, and the acceleration of the instrument. The handheld surgical system according to item 25. [Item 27] The handheld surgical system according to any one of Items 8 to 26, further comprising a position identification indicator that communicates with the control system. [Item 28] The handheld surgical system according to Item 27, wherein the control system controls the position identification indicator based on the shielding event. [Item 29] The handheld surgical system according to Item 28, wherein the position identification indicator is defined as at least one of an auditory indicator, a visual indicator, and a tactile indicator. [Item 30] The handheld surgical system according to Item 28, wherein the position identification indicator is defined as a software routine. [Item 31] The handheld surgical system according to any one of Items 8 to 30, wherein the boundary is a mesh. [Item 32] The handheld surgical system according to Item 31, wherein the mesh is obtained from a patient image. [Item 33] The handheld surgical system according to Item 32, wherein the mesh is obtained from segmentation of the patient image. [Item 34] The handheld surgical system according to any one of Items 8 to 33, further comprising a patient tracking device attached to the patient. [Item 35] The control system further determines at least a partial posture of the patient, The handheld surgical system according to Item 34, wherein the control system is configured to determine that the shielding event has occurred in the patient tracking device. [Item 36] A handheld surgical system, an instrument configured to be held by a user's hand and including a drive motor, a tracking device connected to the instrument, a tracking unit, an alert module, A control system that communicates with the tracking unit and the alert module, determines the posture of the instrument, determines a boundary, controls the alert module based on the boundary and the posture of the instrument, determines that a shielding event has occurred in the tracking device, determines the duration of the shielding event, determines the distance between the instrument and the boundary, and is configured to control the alert module based on the shielding event, the duration of the shielding event, the boundary, the posture of the instrument, and the distance between the instrument and the boundary. A control system, A handheld surgical system comprising the same. [Item 37] A handheld surgical system, an instrument configured to be held by a user's hand and including a drive motor, a console connected to the instrument, a tracking device connected to the instrument, a tracking unit, an alert module, and a control system that communicates with the tracking unit, the alert module, and the console, determines the posture of the instrument, determines a boundary, controls the alert module based on the boundary and the posture of the instrument, determines that a shielding event has occurred in the tracking device, determines the distance between the instrument and the boundary based on the boundary and the posture of the instrument, and is configured to control the drive motor based on the distance and the shielding event. A control system, A handheld surgical system comprising the same. [Item 38] The handheld surgical system according to item 37, wherein the control system determines a distance threshold, and when the distance between the instrument and the boundary is less than the distance threshold when a shielding event occurs, the drive motor is configured to be controlled. [Item 39] The handheld surgical system according to item 37 or 38, wherein an end effector is incorporated in the instrument, and the distance between the instrument and the boundary is determined by the length of a straight line between the end effector and the point on the boundary closest to the end effector. [Item 40] The handheld surgical system according to item 39, wherein the straight line is orthogonal to the boundary and intersects the point on the boundary closest to the end effector. [Item 41] The handheld surgical system according to item 39 or 40, wherein the end effector is a bar including a bar head, and the straight line is between the center of the bar head and the boundary. [Item 42] The handheld surgical system according to item 39 or 40, wherein the end effector is a drill bit including a tip portion, and the straight line is between the tip portion of the drill bit and the boundary. [Item 43] The handheld surgical system according to item 41 or 42, wherein the control system is further configured to determine the direction of the distance with respect to the boundary by using ray casting. [Item 44] The ray casting includes emitting a light ray from the center of the bar to the shaft of the bar, The handheld surgical system according to item 43, wherein when the light ray intersects the boundary, the control system determines that the center of the bar has passed over the boundary. [Item 45] The ray casting includes emitting a light ray from the tip portion of the drill bit to the remaining portion of the drill bit, The handheld surgical system according to item 43, wherein when the light ray intersects the boundary, the control system determines that the center of the bar has passed beyond the boundary. [Item 46] The handheld surgical system according to item 39, wherein the end effector is a driver including a tip, and the straight line is between the tip of the driver and the center of the planned position of the screw. [Item 47] The handheld surgical system according to item 39, wherein the end effector is a screw including a tip, and the straight line is between the tip of the screw and the center of the planned position of the screw. [Item 48] The boundary is recognized as a spherical virtual boundary surrounding this position with the planned screw position as the center, and the planned screw position has a length. The diameter of the spherical virtual boundary is equal to the length of the planned screw position. The handheld surgical system according to item 46 or 47, wherein the straight line is between the tip of the screw and the center of the spherical virtual boundary. [Item 49] The handheld surgical system according to item 48, wherein the control system determines a distance threshold, and when the distance is less than the distance threshold when a shielding event occurs, the control system is configured to control the drive motor. [Item 50] The control system determines an adjustment distance between the tip of the screw and the edge of the spherical virtual boundary as a value obtained by subtracting the radius of the spherical virtual boundary from the length of the straight line. The handheld surgical system according to item 48, wherein the control system determines a distance threshold, and when the adjustment distance is less than the distance threshold when a shielding event occurs, the control system is configured to control the drive motor. [Item 51] The planned screw position is recognized as a first planned screw position. The spherical virtual boundary is recognized as a first spherical virtual boundary centered on and surrounding the first planned screw position. The straight line is recognized as a first straight line between the tip of the screw and the center of the first spherical virtual boundary. The boundary further includes a second spherical virtual boundary centered on a second predetermined screw position and surrounding it. The diameter of the second spherical virtual boundary is equal to the length of the second predetermined screw position. A second straight line is determined between the tip of the screw and the center of the second spherical virtual boundary. The handheld surgical system according to item 48, wherein the distance between the instrument and the boundary is determined as the shorter one of the first straight line and the second straight line. [Item 52] The handheld surgical system according to item 51, wherein the control system determines a distance threshold, and when the distance is less than the distance threshold when a shielding event occurs, the control system is configured to control the drive motor. [Item 53] The control system determines an adjustment distance between the tip of the screw and the edge of the spherical virtual boundary as a value obtained by subtracting the radius of each spherical virtual boundary from the length of the shorter straight line. The handheld surgical system according to item 51, wherein the control system determines a distance threshold, and when the adjustment distance is less than the distance threshold when a shielding event occurs, the control system is configured to control the drive motor. [Item 54] The control system further determines the duration of the shielding event, The handheld surgical system according to any one of items 37 to 53, wherein the control system is configured to control the drive motor based on the duration, the distance, and the shielding event. [Item 55] The handheld surgical system according to item 54, wherein the control system determines a duration threshold, and when the duration of the shielding event is longer than the duration threshold, the control system is configured to control the drive motor. [Item 56] The handheld surgical system according to item 55, wherein the duration threshold is based on the distance. [Item 57] When the distance indicates that the instrument is outside the boundary, the duration threshold is recognized as a first duration threshold, and when the distance indicates that the instrument has crossed the boundary, the duration threshold is recognized as a second duration threshold. The handheld surgical system according to item 56, wherein the second duration threshold is shorter than the first duration threshold. [Item 58] When the distance indicates that the instrument is within the distance threshold of the boundary, the duration threshold is recognized as a first duration threshold, and when the distance indicates that the instrument is not within the distance threshold of the boundary, the duration threshold is recognized as a second duration threshold. The handheld surgical system according to item 56, wherein the second duration threshold is longer than the first duration threshold. [Item 59] The handheld surgical system according to any one of items 37 to 58, further comprising a position-specific recognition indicator that communicates with the control system. [Item 60] The handheld surgical system according to item 59, wherein the control system controls the position-specific recognition indicator based on the shielding event.

Claims

1. It is a handheld surgical system, A device including a drive motor, configured to be held in the user's hand, A tracking device connected to the aforementioned device, A tracking unit configured to work in conjunction with the tracking device to generate tracking data indicating the orientation of the instrument in a known coordinate system, An alert module for indicating the position of the instrument relative to the area of ​​interest in surgical procedures, A control system that communicates with the tracking unit, the alert module, and the device, Based on the aforementioned tracking data, the orientation of the instrument in the known coordinate system is tracked. Determine the boundary in the known coordinate system associated with the region of interest, The alert module is controlled based on the boundary in the known coordinate system and the tracked orientation of the instrument. The tracking device determines that an obstruction event has occurred, A control system configured to disable the drive motor based on the shielding event, the boundary, and the tracked orientation of the device, A handheld surgical system equipped with [features / equipment].

2. The control system further, Determine the duration of the aforementioned shielding event, The handheld surgical system according to claim 1, configured to deactivate the drive motor based on the duration of the shielding event, the boundary, and the tracked orientation of the instrument.

3. The control system further, A duration threshold is determined based on the boundary and the tracked orientation of the device. The handheld surgical system according to claim 2, configured to disable the drive motor based on the duration and duration threshold of the shielding event.

4. The boundary is defined as the first boundary, and the control system further, Determine a second boundary in the known coordinate system that is located further from the region of interest than the first boundary in the known coordinate system. Based on the tracked orientation of the instrument, the position of the end effector of the instrument is determined with respect to the first and second boundaries in the known coordinate system. In response to the determination that the end effector is outside the first and second boundaries in the known coordinate system, the duration threshold is set to the first duration. The handheld surgical system according to claim 3, wherein, in response to a determination that the end effector is between the first boundary and the second boundary in the known coordinate system, the duration threshold is configured to set to a second duration which is less than the first duration.

5. The control system further, Based on the boundary in the known coordinate system and the tracked orientation of the instrument, the positional relationship between the instrument and the region of interest is determined. The handheld surgical system according to claim 3, configured to determine the duration threshold based on the aforementioned positional relationship.

6. The control system further, Based on the boundary in the known coordinate system and the tracked orientation of the instrument, the distance between the instrument and the region of interest is determined. The handheld surgical system according to claim 3, configured to determine the duration threshold based on the distance.

7. The handheld surgical system according to claim 6, wherein the instrument incorporates an end effector, and the control system is configured to determine the distance between the instrument and the region of interest by determining the distance between the end effector and the boundary in the known coordinate system.

8. The handheld surgical system according to claim 7, wherein the control system is configured to determine the distance between the end effector and the boundary in the known coordinate system based on the length of a straight line between the end effector and the point on the boundary closest to the end effector in the known coordinate system.

9. The handheld surgical system according to claim 8, wherein the straight line is perpendicular to the boundary and intersects the point on the boundary closest to the end effector.

10. The handheld surgical system according to claim 8 or 9, wherein the end effector is a bar including a bar head, and the straight line is between the center of the bar head and the boundary.

11. The handheld surgical system according to claim 8 or 9, wherein the end effector is a drill bit including a tip, and the straight line is between the tip of the drill bit and the boundary.

12. The handheld surgical system according to claim 7, wherein the end effector is a driver including a tip, and the control system is configured to determine the distance between the end effector and the boundary based on the length of a straight line between the tip of the driver and the center of the planned position of the screw in the known coordinate system.

13. The handheld surgical system according to claim 7, wherein the end effector is a screw including a tip, and the control system is configured to determine the distance between the end effector and the boundary based on the length of a straight line between the tip of the screw and the center of the planned position of the screw in the known coordinate system.

14. A navigation system used with an instrument configured to be held in the user's hand, the instrument including a drive motor and an alert module for indicating the position of the instrument relative to a surgical region of interest, A tracking unit configured to generate tracking data indicating the orientation of the instrument in a known coordinate system, in cooperation with a tracking device connected to the instrument, A control system that communicates with the tracking unit, the alert module, and the device, Based on the aforementioned tracking data, the orientation of the instrument in the known coordinate system is tracked. The boundary in the known coordinate system, which is associated with the region of interest, is determined. The alert module is controlled based on the boundary in the known coordinate system and the tracked orientation of the instrument. The tracking device determines that an obstruction event has occurred, A control system configured to disable the drive motor based on the shielding event, the boundary, and the tracked orientation of the device, A navigation system equipped with this feature.

15. A computer implementation program for tracking an instrument configured to be held in the hand of a user and including a drive motor, which, when executed by a control system, A step of tracking the orientation of the instrument in a known coordinate system based on tracking data generated by a tracking unit linked to a tracking device connected to the instrument, The steps include determining a boundary in the known coordinate system that is associated with the region of interest in the surgical procedure, The steps include controlling an alert module configured to indicate the position of the instrument relative to the region of interest, based on the boundary and the tracked orientation of the instrument in the known coordinate system, The step of determining that an occlusion event has occurred in the tracking device, The steps include disabling the drive motor based on the shielding event, the boundary, and the tracked orientation of the device, A computer implementation program that includes instructions to cause the control system to execute the above.

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