Systems and methods for using a force-torque sensor of a surgical robot to estimate kerf

Abstract

A robotic surgical system includes a tracking system configured to facilitate tracking of a robotic arm within a coordinate system. The tracking system comprises a force-torque sensor configured to be in force transmitting contact with the robotic arm and an end effector that supports a surgical tool for removing a portion of an anatomical element of a patient. At least one processor is configured to monitor kerf of the removed portion of the anatomical element based on output of the force-torque sensor, determine that the monitored kerf reaches a threshold, and output one or more signals in response to determining that the monitored kerf has reached the threshold.

Description

A0012601SYSTEMS AND METHODS FOR USING A FORCE-TORQUE SENSOR OF A SURGICAL ROBOT TO ESTIMATE KERF

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 730,609, filed 11 December 2024, the entire content of which is incorporated herein by reference.BACKGROUND

[0002] The present disclosure is generally directed to systems and methods for using a forcetorque sensor to estimate kerf during a removal procedure (e.g., bone removal).

[0003] Surgical robots may assist a surgeon or other medical provider in carrying out a surgical procedure, or may complete one or more surgical procedures autonomously. Various tools, referred to as end effectors, may be used to carry out the surgical procedure with the aid of imaging devices.BRIEF SUMMARY

[0004] Example aspects of the present disclosure include:

[0005] A robotic surgical system, comprising: a tracking system configured to facilitate tracking of a robotic arm within a coordinate system, the tracking system comprising a force-torque sensor configured to be in force transmitting contact with the robotic arm and an end effector that supports a surgical tool for removing a portion of an anatomical element of a patient; and at least one processor configured to: monitor kerf of the removed portion of the anatomical element based on output of the force-torque sensor; and determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

[0006] A device, comprising: at least one processor; and memory comprising instructions that when executed by the processor, cause the processor to: monitor kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor in forcetransmitting contact with a robotic arm and the surgical tool; determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

[0007] A method, comprising: monitoring kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor in force-transmitting contact with a robotic arm and the surgical tool; determining that the monitored kerf reaches a threshold; andA0012601 outputting one or more signals in response to determining that the monitored kerf has reached the threshold.

[0008] Any aspect in combination with any one or more other aspects.

[0009] Any one or more of the features disclosed herein.

[0010] Any one or more of the features as substantially disclosed herein.

[0011] Any one or more of the features as substantially disclosed herein in combination with any one or more other features as substantially disclosed herein.

[0012] Any one of the aspects / features / embodiments in combination with any one or more other aspects / features / embodiments .

[0013] Use of any one or more of the aspects or features as disclosed herein.

[0014] It is to be appreciated that any feature described herein can be claimed in combination with any other feature(s) as described herein, regardless of whether the features come from the same described embodiment.

[0015] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.

[0016] The phrases “at least one”, “one or more”, and “and / or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and / or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. When each one of A, B, and C in the above expressions refers to an element, such as X, Y, and Z, or class of elements, such as XI -Xn, Yl-Ym, and Zl-Zo, the phrase is intended to refer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., XI and X2) as well as a combination of elements selected from two or more classes (e.g., Y1 and Zo).

[0017] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.

[0018] The preceding is a simplified summary of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various aspects, embodiments, and configurations. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailedA0012601 description presented below. As will be appreciated, other aspects, embodiments, and configurations of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.

[0019] Numerous additional features and advantages of the present disclosure will become apparent to those skilled in the art upon consideration of the embodiment descriptions provided hereinbelow.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0020] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the disclosure. The drawings simply illustrate preferred and alternative examples of how the disclosure can be made and used and are not to be construed as limiting the disclosure to only the illustrated and described examples. Further features and advantages will become apparent from the following, more detailed, description of the various aspects, embodiments, and configurations of the disclosure, as illustrated by the drawings referenced below.

[0021] Fig. 1A shows aspects of a system according to at least one embodiment of the present disclosure.

[0022] Fig. IB shows additional aspects of the system according to at least one embodiment of the present disclosure.

[0023] Fig. 1C shows aspects of a tracking system according to at least one embodiment of the present disclosure.

[0024] Fig. ID shows aspects of an end effector according to at least one embodiment of the present disclosure.

[0025] Figs. 2A and 2B show various views of a tool changer according to at least one embodiment of the present disclosure.

[0026] Fig. 2C shows distal end view of a tracking system according to at least one embodiment of the present disclosure.

[0027] Fig. 3 illustrates a flow chart for a method according to at least one embodiment of the present disclosure.

[0028] Fig. 4A illustrates a flow chart for a method according to at least one embodiment of the present disclosure.

[0029] Fig. 4B illustrates a flow chart for a method according to at least one embodiment of the present disclosure.A0012601DETAILED DESCRIPTION

[0030] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example or embodiment, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, and / or may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the disclosed techniques according to different embodiments of the present disclosure). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a computing device and / or a medical device.

[0031] In one or more examples, the described methods, processes, and techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Alternatively or additionally, functions may be implemented using machine learning models, neural networks, artificial neural networks, or combinations thereof (alone or in combination with instructions). Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0032] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors (e.g., Intel Core i3, i5, i7, or i9 processors; Intel Celeron processors; Intel Xeon processors; Intel Pentium processors; AMD Ryzen processors; AMD Athlon processors; AMD Phenom processors; Apple A10 or 10X Fusion processors; Apple Al l, A12, A12X, A12Z, or A13 Bionic processors; or any other general purpose microprocessors), graphics processing units (e.g., Nvidia GeForce RTX 2000-series processors, Nvidia GeForce RTX 3000-series processors, AMD Radeon RX 5000-series processors, AMD Radeon RX 6000-series processors, or any other graphics processing units), application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.A0012601

[0033] Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, the present disclosure may use examples to illustrate one or more aspects thereof. Unless explicitly stated otherwise, the use or listing of one or more examples (which may be denoted by “for example,” “by way of example,” “e.g.,” “such as,” or similar language) is not intended to and does not limit the scope of the present disclosure.

[0034] The terms proximal and distal are used in this disclosure with their conventional medical meanings, proximal being closer to the operator or user of the system, and further from the region of surgical interest in or on the patient, and distal being closer to the region of surgical interest in or on the patient, and further from the operator or user of the system.

[0035] When performing robotics assisted surgery, some of the main risks include injury to the patient’s spinal cord and other, less severe, potential temporary or permanent harm to the patient. Therefore, it is important to have a system that is as accurate and robust as possible to minimize the chance of patient harm. The point of interest for accuracy in a cutting or drilling operation is called the TCP (tool center point) and is usually the distal-most point of a surgical tool (e.g., the tip of a bone removal tool), or the point where a tool makes contact with the patient.

[0036] One of the contributors to inaccuracy, especially in active robotic procedures, such as bone removal procedures, is the dynamic response of the entire system (e.g., the robot cart, robotic arm, tracking system, tool changer, and end effector) and how the system reacts and moves under vibrations caused by either external sources, or (more likely) internal sources, such as a motorized bone removal tool attached to the robotic arm.

[0037] When vibrations occur at a resonant frequency, this causes a system to resonate with maximum amplitude. Prolonged operation at the resonant frequency can escalate the vibrational amplitude, increasing the risk of the system losing control and sustaining damage. In the case of surgical robotic systems, vibrations, especially at the resonant frequency, may also result in patient harm due to the bone removal tool tip vibrating and increasing the kerf (width of a cut) and / or the depth of the cut. For example, the kerf of a cutting tool under ideal or normal conditions may be 4mm but due to vibrations of the overall system (e.g., at resonant frequency or otherwise), the kerfA0012601 may approach 4.5mm which could be an unsafe value if removing tissue or bone near a damagesensitive area such as a spinal cord or other nerve.

[0038] Example embodiments propose to use a tracking system, also termed herein as a Robotic Tracking Unit (RTU), attached to a distal end of a robotic arm and which facilitates the connection of end effectors to the robotic arm for carrying out surgery. Such an RTU may also add functionality to an off-the-shelf robotic arm, such as 3D imaging, LED indications, user interfaces (buttons), a tool changer acting an electrical and mechanical interface for end effectors, and a six degrees of freedom force-torque sensor at the distal end of the RTU. In at least one embodiment, the forcetorque sensor of the RTU and / or other similar sensors at joints of the robotic arm are used to implement a safety layer method that involves estimating the kerf in a robotic bone removal procedure and taking appropriate actions when needed.

[0039] In at least one example, the force-torque (FT) sensor may act as an accelerometer, monitoring accelerations of the system at various points of interest. Real-time accelerometer data from the FT sensor may then be used to estimate current kerf in at least two ways: 1) a lookup table built empirically by measuring actual kerf under different variables such as load on end effector, direction of load, arm position, arm movement speed, end effector working frequency, cut depth, and / or anatomical element variables (density, size, shape, type) - in this method, kerf values are retrieved from the lookup table in real time; and 2) performing a double integration on a measured acceleration (e.g., at the tip of the surgical tool) to calculate the actual displacement of the tip of the surgical too since displacement(t) = \velocity(t)dt = J ( \acceleration(i)di)di - here, the displacement is calculated in the relevant direction (e.g., perpendicular to the robotic arm movement direction) and will give the actual real-time kerf without interpolation and / or sensitivity to system and / or anatomical element variables. In some examples, cut depth may also be calculated, such as by measuring acceleration in a direction that informs on cut depth.

[0040] Monitoring kerf in real time during a tissue or bone removal procedure may serve several purposes. In some examples, the monitored kerf is compared to a threshold (e.g., a variable threshold that could change according to procedure type, type of anatomy, and / or surgeon input). When the monitored kerf reaches the threshold, the system may issue an audio and / or visual alert that informs the surgeon to stop operation. In some examples, reaching the kerf threshold will automatically stop the motion of the robotic arm and / or the operation of the surgical tool. In some examples, reaching the kerf threshold automatically adjusts operating parameters of the surgical tool (tool operating frequency, robotic arm speed, downward tool force, etc.) so as to avoid exceeding a second kerf threshold considered unsafe for the procedure. As may be appreciated then, monitoring kerf in realA0012601 time may reduce or minimize the risk of harm to a patient due to overly wide or deep cuts. In addition, providing alerts or automatic control mechanisms instills confidence regarding the device's safety and reliability, fostering trust in its use for medical applications.

[0041] Embodiments of the present disclosure provide technical solutions to one or more of the problems of (1) patient safety during a bone removal procedure and / or (2) time / cost associated with additional instrumentation for taking real time kerf measurements, in addition to other problems that one may appreciate as being solved by embodiments set forth herein.

[0042] Figs 1A-1D illustrate elements of a system 100 according to an embodiment of the present disclosure. The system 100 may be used to carry out a robot-assisted surgery or procedure and / or carry out one or more other aspects of one or more of the methods disclosed herein. The system 100 comprises one or more imaging device(s) 112, a robot 114, a navigation system 118, a database 130, a tracking system 132, a cloud or other network 134, a tool changer 136, an end effector 140. Systems according to other embodiments of the present disclosure may comprise more or fewer components than the system 100. For example, the system 100 may not include the imaging device 112, the database 130, the cloud 134, and / or the tool changer 136 (in which case the end effector 140 may be attached to the tracking system 132 or an upstream part of the robot 114).

[0043] The imaging device 112 may be operable to image anatomical feature(s) (e.g., a bone, veins, tissue, etc.) and / or other aspects of patient anatomy to yield image data (e.g., image data depicting or corresponding to a bone, veins, tissue, etc.). “Image data” as used herein refers to the data generated or captured by an imaging device 112, including in a machine-readable form, a graphical / visual form, and in any other form. In various examples, the image data may comprise data corresponding to an anatomical feature of a patient, or to a portion thereof. The image data may be or comprise a preoperative image, an intraoperative image, a postoperative image, or an image taken independently of any surgical procedure. In some embodiments, a first imaging device 112 may be used to obtain first image data (e.g., a first image) at a first time, and a second imaging device 112 may be used to obtain second image data (e.g., a second image) at a second time after the first time. The imaging device 112 may be capable of taking a two-dimensional (2D) image or a three- dimensional (3D) image to yield the image data. The imaging device 112 may be or comprise, for example, an ultrasound scanner (which may comprise, for example, a physically separate transducer and receiver, or a single ultrasound transceiver), an 0-arm, a C-arm, a G-arm, or any other device utilizing X-ray-based imaging (e.g., a fluoroscope, a CT scanner, or other X-ray machine), a magnetic resonance imaging (MRI) scanner, an optical coherence tomography (OCT) scanner, an endoscope, a microscope, an optical camera, a thermographic camera (e.g., an infrared camera), aA0012601 radar system (which may comprise, for example, a transmitter, a receiver, a processor, and one or more antennae), or any other imaging device 112 suitable for obtaining images of an anatomical feature of a patient. The imaging device 112 may be contained entirely within a single housing, or may comprise a transmitter / emitter and a recei ver / detector that are in separate housings or are otherwise physically separated.

[0044] In some embodiments, the imaging device 112 may comprise more than one imaging device 112. For example, a first imaging device may provide first image data and / or a first image, and a second imaging device may provide second image data and / or a second image. In still other embodiments, the same imaging device may be used to provide both the first image data and the second image data, and / or any other image data described herein. The imaging device 112 may be operable to generate a stream of image data. For example, the imaging device 112 may be configured to operate with an open shutter, or with a shutter that continuously alternates between open and shut so as to capture successive images. For purposes of the present disclosure, unless specified otherwise, image data may be considered to be continuous and / or provided as an image data stream if the image data represents two or more frames per second.

[0045] The robot 114 comprises one or more robotic arms 116, a processor 120, a memory 122, a communication interface 124, and a controller 128. Robots according to other embodiments of the present disclosure may comprise more or fewer components than the robot 114. In some embodiments, the robot 114 may be mechanically coupled with (e.g., affixed to, attached to, mounted to, etc.) a patient bed or table. In other embodiments, the robot 114 may be disposed on a robot cart 144. The robot cart 144 may be a mobile platform that enables the robot 114 and / or components thereof to be positioned relative to the patient and / or the bed or table on which the patient is positioned. In some embodiments, the robot cart 144 may comprise wheels that enable the robot cart 144 to roll or move relative to the patient. The robot cart 144 may be detachable from the wheels or the wheels may be lockable such that, once the robot cart 144 is positioned in a desired location relative to the patient, the robot cart 144 will remain fixed in the desired location. In other words, the robot cart 144 may have a mechanism that enables the robot cart 144 to remain fixed relative to the patient. The mechanism may better ensure that the robot 114 and / or any other components on the robot cart 144 do not move relative to the patient due to the mobility of the robot cart 144 once the robot cart 144 has been positioned in the desired location.

[0046] The robot 114 may be or comprise any surgical robot or surgical robotic system. The robot 114 may be or comprise, for example, the Mazor X™ Stealth Edition robotic guidance system or successor thereof. The robot 114 may be configured to position the imaging device 112 at one orA0012601 more precise position(s) and orientation(s), and / or to return the imaging device 112 to the same position(s) and orientation(s) at a later point in time. The robot 114 may additionally or alternatively be configured to manipulate the end effector 140 and / or a component thereof such as a surgical tool (whether based on guidance from the navigation system 118 or not) to accomplish or to assist with a surgical task. In some embodiments, the robot 114 may be configured to hold and / or manipulate an anatomical element during or in connection with a surgical procedure.

[0047] In some embodiments, the robotic arm 116 may comprise a first robotic arm and a second robotic arm, though the robot 114 may comprise more or fewer than two robotic arms. In some embodiments, one or more of the robotic arms 116 may be used to hold and / or maneuver the imaging device 112. In embodiments where the imaging device 112 comprises two or more physically separate components (e.g., a transmitter and receiver), one robotic arm 116 may hold one such component, and another robotic arm 116 may hold another such component. Each robotic arm 116 may be positionable independently of the other robotic arm. The robotic arms 116 may be controlled in a single, shared coordinate space, or in separate coordinate spaces.

[0048] The robot 114, together with the robotic arm 116, may have, for example, one, two, three, four, five, six, seven, or more degrees of freedom. Further, the robotic arm 116 may be positioned or positionable in any pose, plane, and / or focal point. The pose includes a position and an orientation. As a result, an imaging device 112, the tracking system 132, the tool changer 136, the end effector 140 and components thereof such as a surgical tool, or other object held by or connected to the robot 114 (or, more specifically, held by or connected to the robotic arm 116) may be precisely positionable in one or more needed and specific positions and orientations.

[0049] The robotic arm(s) 116 may comprise one or more sensors that enable the processor 120 (or another processor of another component of the system 100) to determine a precise pose in space of the robotic arm (as well as any object or element held by or secured to the robotic arm such as the tracking system 132, the tool changer 136, and / or the end effector 140).

[0050] With reference to Fig. IB, the processor 120 of the robot 114 may be any processor described herein or any similar processor. The processor 120 may be configured to execute instructions stored in the memory 122, which instructions may cause the processor 120 to carry out one or more computing steps utilizing or based on data received from the imaging device 112, the navigation system 118, the database 130, the cloud 134, and / or the end effector 140. The processor 120 may be or comprise one or more digital signal processors (DSPs), general purpose microprocessors (e.g., Intel Core i3, i5, i7, or i9 processors; Intel Celeron processors; Intel Xeon processors; Intel Pentium processors; AMD Ryzen processors; AMD Athlon processors; AMDA0012601Phenom processors; Apple A10 or 10X Fusion processors; Apple Al l, Al 2, A12X, A12Z, or Al 3 Bionic processors; or any other general purpose microprocessors), graphics processing units (e.g., Nvidia GeForce RTX 2000-series processors, Nvidia GeForce RTX 3000-series processors, AMD Radeon RX 5000-series processors, AMD Radeon RX 6000-series processors, or any other graphics processing units), application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry.

[0051] The memory 122 may be or comprise RAM, DRAM, SDRAM, other solid-state memory, any memory described herein, or any other tangible, non-transitory memory for storing computer- readable data and / or instructions. The memory 122 may store information or data useful for completing, for example, one or more steps of the methods described herein, or of any other methods. In one embodiment, the memory 122 comprises an EEPROM. The memory 122 may store, for example, instructions and / or machine learning models that support one or more functions of the robot 114. For instance, the memory 122 may store content (e.g., instructions and / or machine learning models) that, when executed by the processor 120, enable image processing, segmentation, transformation, and / or registration. Such content, if provided as in instruction, may, in some embodiments, be organized into one or more applications, modules, packages, layers, or engines. Alternatively or additionally, the memory 122 may store other types of content or data (e.g., machine learning models, artificial neural networks, deep neural networks, etc.) that can be processed by the processor 120 to carry out the various method and features described herein. Thus, although various contents of memory 122 may be described as instructions, it should be appreciated that functionality described herein can be achieved through use of instructions, algorithms, and / or machine learning models. The data, algorithms, and / or instructions may cause the processor 120 to manipulate data stored in the memory 122 and / or received from or via the imaging device 112, the database 130, the tracking system 132, the cloud 134, the tool changer 136, and / or the end effector 140.

[0052] The communication interface 124 may be used for receiving image data or other information from an external source (such as the imaging device 112, the navigation system 118, the database 130, the tracking system 132, the cloud 134, the tool changer 136, the end effector 140, and / or any other system or component not part of the system 100), and / or for transmitting instructions, images, or other information to an external system or device (e.g., the imaging device 112, the robot 114, the navigation system 118, the database 130, the tracking system 132, the cloud 134, the tool changer 136, the end effector 140, and / or any other system or component not part of the system 100). The communication interface 124 may comprise one or more wired interfaces (e.g., a USB port, an Ethernet port, a Firewire port) and / or one or more wireless transceivers or interfacesA0012601(configured, for example, to transmit and / or receive information via one or more wireless communication protocols such as 802.11a / b / g / n, Bluetooth, NFC, ZigBee, and so forth). In some embodiments, the communication interface 124 may be useful for enabling the robot 114 (or one or more components thereof) to communicate with one or more other processors discussed herein, whether to reduce the time needed to accomplish a computing-intensive task or for any other reason.

[0053] The controller 128 may be configured to automatically control one or more functions and / or components of the robot 114. In some embodiments, the controller 128 may utilize the processor 120 to perform computations during the course of controlling the one or more functions and / or components of the robot 114. In some embodiments, the controller 128 may be configured to actuate one or more motors in one or more joints of the robotic arm 116 to, for example, cause the robotic arm 116 to move. In some embodiments, the controller 128 may receive information from the tracking system 132, the tool changer 136, and / or the end effector 140, and use such information to authenticate and control the tracking system 132, the tool changer 136, and / or end effector 140. For example, the controller 128 may receive authentication information from the end effector 140, and compare such information to information stored, for example, in the database 130. When the authentication information from the end effector 140 does not match the information in the database 130, the controller 128 may prevent the end effector 140 from being used in the surgery or surgical procedure. In another example, the controller 128 may receive usage information from the tracking system 132 associated with a number of times the end effector 140 has been used. If the number of times the end effector 140 has been used exceeds a threshold value, the controller 128 may prevent the end effector 140 from being used in the surgery or surgical procedure. Such information stored in the tracking system 132, the tool changer 136, and the end effector 140 and received by the controller 128 is discussed in further detail below.

[0054] Still with reference to Fig. IB, the navigation system 118 may provide navigation for a surgeon and / or a surgical robot during an operation. The navigation system 118 may be any now- known or future-developed navigation system, including, for example, the Medtronic StealthStation™ S8 surgical navigation system or any successor thereof. The navigation system 118 may include one or more cameras or other sensor(s) for tracking one or more reference markers, navigated trackers, or other objects within the operating room or other room in which some or all of the system 100 is located. The one or more cameras may be optical cameras, infrared cameras, or other cameras. In some embodiments, the navigation system 118 may comprise one or more electromagnetic sensors. In various embodiments, the navigation system 118 may be used to track a position and orientation (referred to as a pose) of the imaging device 112, the robot 114, the roboticA0012601 arm 116, and / or the tracking system 132, and components thereof, and / or one or more surgical tools (or, more particularly, to track a pose of a navigated tracker attached, directly or indirectly, in fixed relation to the one or more of the foregoing). The navigation system 118 may include a display (including, for example, the user interface 110) for displaying one or more images from an external source (e.g., imaging device 112 or other source) or for displaying an image and / or video stream from the one or more cameras or other sensors of the navigation system 118. In some embodiments, the system 100 can operate without the use of the navigation system 118. The navigation system 118 may be configured to provide guidance to a surgeon or other user of the system 100 or a component thereof, to the robot 114, or to any other element of the system 100 regarding, for example, a pose of one or more anatomical elements, whether or not a tool is in the proper trajectory, and / or how to move a tool into the proper trajectory to carry out a surgical task according to a preoperative or other surgical plan. The navigation system 118 comprises a processor 104, a memory 106, a communication interface 108, and a user interface 110.

[0055] In some embodiments, reference markers (e.g., navigation markers) may be placed on the imaging device 112, the robot 114 (including, e.g., on the robotic arm 116), or any other object in the surgical space. As described with reference to Fig. 1C, for example, one or more navigation markers 150 (e.g., infrared Light Emitting Diodes (IRLEDs)) on the tracking system 132 may be used as reference markers that the navigation system uses to track the robotic arm 116 and / or the end effector 140. The reference markers may be tracked by the navigation system 118, and the results of the tracking may be used by the robot 114 and / or by an operator of the system 100 or any component thereof. In some embodiments, the navigation system 118 can be used to track other components of the system (e.g., imaging device 112).

[0056] The processor 104 may be similar to or the same as any processor discussed herein (e.g., the processor 120). The processor 104 may be configured to execute instructions stored in the memory 106, which instructions may cause the processor 104 to carry out one or more computing steps utilizing or based on data received from the imaging device 112, the robot 114, the database 130, the cloud 134, and / or any other component of the system 100.

[0057] The memory 106 may be similar to or the same as any memory discussed herein (e.g., the memory 122). The memory 106 may be or comprise RAM, DRAM, SDRAM, other solid-state memory, any memory described herein, or any other tangible, non-transitory memory for storing computer-readable data and / or instructions. In one embodiment, the memory 106 comprises an EEPROM. The memory 106 may store information or data useful for completing, for example, one or more steps of the methods described herein, or of any other methods.A0012601

[0058] The communication interface 108 may be similar to or the same as any communication interface discussed herein (e.g., the communication interface 124). The communication interface 108 may be used for receiving image data or other information from an external source (such as the imaging device 112, the robot 114, the database 130, the cloud 134, and / or any other system or component not part of the system 100), and / or for transmitting instructions, images, or other information to an external system or device (e.g., the imaging device 112, the robot 114, the database 130, the cloud 134, and / or any other system or component not part of the system 100).

[0059] The user interface 110 may be or comprise one or multiple user interfaces. The user interface 110 may be or comprise a keyboard, mouse, trackball, monitor, television, screen, touchscreen, and / or any other device for receiving information from a user and / or for providing information to a user. The user interface 110 may be used, for example, to receive a user selection or other user input regarding any step of any method described herein. Notwithstanding the foregoing, any required input for any step of any method described herein may be generated automatically by the system 100 (e.g., by the processor 104, the processor 120, or another component of the system 100) or received by the system 100 from a source external to the system 100. In some embodiments, the user interface 110 may be useful to allow a surgeon or other user to modify instructions to be executed by the processor 104 (or in some embodiments the processor 120) according to one or more embodiments of the present disclosure, and / or to modify or adjust a setting of other information displayed on the user interface 110 or corresponding thereto.

[0060] Although the user interface 110 is shown as part of the navigation system 118, in some embodiments, the processor 104 and / or the processor 120 (or any other processor discussed herein) may utilize a user interface 110 that is housed separately from the navigation system 118. In some embodiments, the user interface 110 may be located proximate one or more other components of the robot 114, while in other embodiments, the user interface 110 may be located remotely from one or more other components of the robot 114.

[0061] The database 130 may store information that correlates one coordinate system to another (e.g., one or more robotic coordinate systems to a patient coordinate system and / or to a navigation coordinate system). The database 130 may additionally or alternatively store, for example, one or more surgical plans (including, for example, pose information about a target and / or image information about a patient’s anatomy at and / or proximate the surgical site, for use by the robot 114, the navigation system 118, and / or a user of the system 100; information about planned surgical tools to be used and connected to the robotic arm 116 to carry out the surgery or surgical procedure); one or more images useful in connection with a surgery to be completed by or with the assistance of oneA0012601 or more other components of the system 100; information related to the tracking system 132, the tool changer 136, and / or the end effector 140, and / or any other useful information. The database 130 may be configured to provide any such information to any device of the system 100 or external to the system 100, whether directly or via the cloud 134. In some embodiments, the database 130 may be or comprise part of a hospital image storage system, such as a picture archiving and communication system (PACS), a health information system (HIS), and / or another system for collecting, storing, managing, and / or transmitting electronic medical records including image data.

[0062] The cloud 134 may be or represent the Internet or any other wide area network. The robot 114, the navigation system 118, the database 130, and / or the like may be connected to the cloud 134 via the communication interface 108 and / or the communication interface 124, using a wired connection, a wireless connection, or both. In some embodiments, one or more components of the system 100 may communicate with the imaging device 112, the database 130, any other component of the system 100, and / or an external device (e.g., a computing device outside the system 100) via the cloud 134.

[0063] With reference to Figs. IB and 1C, the tracking system 132, which may correspond to an RTU, has a proximal end with an interface that is connectable to the distal end of the robotic arm 116 to attach the tracking system 132 to the robotic arm 116. The tracking system 132 has a distal end that facilitates connection of the tracking system 132 to the tool changer 136. In general, the tracking system 132 remains on the robotic arm 116 through the course of the surgery or surgical procedure. The tracking system 132 may comprise a tracking device 134 that includes components used for tracking the system 132 itself, the robotic arm 116, the tool changer 136, and / or the end effector 140 within a coordinate system, such as a coordinate system formed by the navigation system 118 with the aid of imaging device(s) 112. The tracking device 134 may comprise a processor 148, a memory 152, and one or more passive or active navigation markers 150 (e.g., reflective spheres as passive markers, infrared Light Emitting Diodes (IRLEDs) as active markers). As shown in Fig. 1C, the navigation markers 150A to 150F may be disposed in a predetermined arrangement on the tracking system 132 which may enable, for example, registration with other elements of the system based on the detection of the navigation markers 150 using image data from the imaging devices 112 and processing by the navigation system 118. Additionally or alternatively, the memory 152 of the tracking system 132 may comprise a calibration file including calibration and authentication information that enables the controller 128 to calibrate and authenticate the tracking system 132, as discussed in further detail below. In some embodiments, the tracking system 132 may omit one or more components depicted in Fig. IB. In some embodiments, the tracking system 132A0012601 may comprise additional components, such as temperature sensors, LED driver circuit(s), other sensors used for surgery, communication interfaces, and / or the like.

[0064] With reference to Fig. IB, the processor 148 may be similar to or the same as any processor discussed herein (e.g., the processor 104, the processor 120, etc.). The processor 148 may be configured to execute instructions stored in the memory 152, which instructions may cause the processor 148 to carry out one or more computing steps utilizing or based on data received from the imaging device 112, the robot 114, the database 130, the cloud 134, and / or any other component of the system 100.

[0065] The memory 152 may be similar to or the same as any memory discussed herein (e.g., memory 106, the memory 122, etc.). The memory 152 may be or comprise RAM, DRAM, SDRAM, other solid-state memory, any memory described herein, or any other tangible, non-transitory memory for storing computer-readable data and / or instructions. The memory 152 may store information or data useful for completing, for example, one or more steps of the methods described herein, or of any other methods. In one embodiment, the memory 152 comprises an EEPROM that is programmable to store information specific to the tracking system 132. For example, the EEPROM may comprise information about the position of LEDs on the tracking system 132; specification information associated with the dimensions, operating conditions, and the like of the tracking system 132; usage information associated with the tracking system 132; authentication information of the tracking system 132; and / or any other useful information. Such information may be sent by the processor 148 to the controller 128 upon the tracking system 132 being attached to the robotic arm 116.

[0066] The interface(s) 156 may comprise one or more electrical and / or mechanical interfaces to electrically and mechanically connect interface(s) 164 of the tool changer 136 to the tracking system 132 to enable the tool changer 136 to provide power and control signals to the end effector 140. The end effector 140 may be an active component, such as a motorized surgical tool. In this case, the interfaces 156 may send signals to and receive signals from the end effector 140 through the tool changer 136 to control the end effector 140 and / or active components of the end effector 140 such as surgical drills, reamers, etc. In some embodiments, power supplied to the interfaces 156 and signals exchanged with the end effector 140 are controlled by the processor 148. In some examples, the end effector 140 comprises a passive component, such as a cylinder that facilitates use of another tool therethrough - whether motorized or non-motorized. In other examples, the end effector 140 is integrated with a surgical tool (e.g., a cutting tool) as an active end effector. The interfaces 156 may control or include a locking mechanism of the tracking system 132 that locks and unlocks the toolA0012601 changer 136 such that the tool changer 136 can or cannot move relative to the tracking system 132. The locking mechanism may be mechanical (e.g., the tool changer 136 is blocked from attaching to or detaching from the tracking system 132 by bolt(s) and / or the like), electrical (e.g., the tool changer 136 receives an electrical signal from the locking mechanism that causes the tool changer 136 to lock or unlock), combinations thereof, and / or the like.

[0067] Again with reference to Figs. IB and 1C, the tracking system 132 may further comprise a force-torque (FT) sensor 158. The FT sensor 158 may be in force-transmitting contact with the robotic arm 116, tool changer 136, and / or end effector 140 (with or without a surgical tool) so as to measure rotational, compressive, and / or tensile forces applied to one or more of these elements. The FT sensor 158 may generate sensor data indicative of these forces and send the sensor data to processor 148 which may generate an alert for excessive forces and / or compensate for forces (e.g., caused by robotic arm 116 deflections). The FT sensor 158 may be a six axis FT sensor that can measure tensile and compression forces as well as elastic deformations and rotational forces around axes. The FT sensor 158 may be located closer to a distal end of the tracking system 132 than a proximal end thereof. The FT sensor 158 may be implemented with suitable force and torque sensing technology, such as a strain gauge sensor. It should be appreciated that the FT sensor 158 may be replaced by a sensor that only senses rotational force (and not necessarily compressive and tensile forces). According to embodiments of the present disclosure, the FT sensor 158 may further generate sensor data used for real-time monitoring of kerf during a bone removal procedure on an anatomical element of a patient. Fig. 3 describes these aspects in more detail.

[0068] The tracking system 132 may comprise one or more output devices 159 configured to issue audio and / or visual alerts based on output of the FT sensor 158. Examples of output devices 159 include but are not limited to light sources (e.g., visible-light LEDs separate from navigation markers 150) for issuing visual alerts, a display for issuing visual alerts with readable text, one or more speakers for issuing audio alerts, and / or the like. In accordance with embodiments of the present disclosure, such alerts may be generated based on output of the FT sensor 158 that is indicative of a real time kerf value during a procedure that removes part of a patient’s anatomy.

[0069] As noted above, the tool changer 136 may comprise one or more electrical and / or mechanical interfaces 164 at the distal and proximal ends thereof that electrically and mechanically connect with an end effector 140 and the tracking system 132. The interfaces 164 are described in more detail below with reference to Figs. 2A and 2B but should generally be understood to include a first type of mechanical connection to the tracking system (e.g., via one or more screws with corresponding screw locators) and a second type of mechanical connection to the end effector (e.g., aA0012601 locking kinematic connection). In some cases, the first and second types of mechanical connections are the same type of connection, such as both being a kinematic connection or both including screws and corresponding screw locators. The tool changer 136 may comprise a distal end interface with fixed dimensions designed to connect to corresponding end effectors 140. Optionally, the tool changer 136 comprises a distal end interface with adjustable dimensions to enable end effectors 140 of different shapes and sizes to be coupled to the robotic arm 116. The tool changer 136 comprises a tool changer controller 160 that generates control signals (or in some cases receive control signals from other components of the system 100) that are passed to the end effector 140. The tool changer controller 160 may control, for example, an interlocking feature of the tool changer 136 such that the end effector 140 can only be uncoupled from the tool changer 136 when the tool changer 136 is positioned near or within a tool stand.

[0070] In one example, the tool changer controller 160 may determine that the tool changer 136 is coupled with the end effector 140. The tool changer controller 160 may determine this information based on sensors, based on signals generated when the end effector 140 has effectively coupled with the tool changer 136, based on the step in the surgical procedure, combinations thereof, and / or the like. Once the tool changer controller 160 determines that the tool changer 136 and the end effector 140 are coupled, the tool changer controller 160 may keep the interlocking feature locked until receiving a further signal. The tool changer controller 160 may generate and / or send the further signal when the tool changer 136 has been placed back in the tool stand (e.g., after the end effector 140 has been used and the surgery or surgical procedure has progressed to the next step), such that the tool changer controller 160 changes the interlocking feature to an unlocked state.

[0071] With reference to Figs. IB and 1C, the tracking device 134 enables the navigation system 118 to track the robotic arm 116. In the illustrated example, the tracking device 134 comprises navigation markers 150A-150F. The navigation markers 150A-150F may be or comprise one or more active markers (e.g., infrared light sources), one or more passive markers (e.g., sections of reflective tape, objects of a particular shape (spheres)), or a combination of active and passive markers. The navigation markers 150A-150F may be, for example, IRLEDs, reflective markers, and / or the like. The navigation system 118 may be configured to obtain pose information describing a pose of the navigation markers 150A-150F, which may be used to determine a correlating pose of the robotic arm 116, the tracking system 132, and / or the end effector 140 (e.g., using transformation 124 and registration 128).

[0072] With reference to Figs. IB and ID, the end effector 140 may include a proximal end having an electromechanical interface that is connectable to an interface 164 of the tool changer 136 and aA0012601 distal end that comprises an operative portion 180 that can be used to carry out one or more surgical tasks. The end effector 140 may comprise an active end effector, such as when the operative portion 180 comprises a surgical tool, or a passive end effector, such as when the operative portion 180 comprises a tool guide. The end effector 140 also comprises a memory 172, and may additionally comprise a processor 168 and a motor controller 176.

[0073] The operative portion 180 may comprise a surgical tool. The surgical tool may be configured to drill, burr, mill, cut, saw, ream, tap, etc. into anatomical tissues such as patient anatomy (e.g., soft tissues, bone, etc.). In some embodiments, the system 100 may comprise multiple surgical tools, with each surgical tool performing a different surgical task (e.g., a surgical drill for drilling, a surgical mill for milling, a curette for removing anatomical tissue, an osteotome for cutting bone, etc.). In other embodiments, the surgical tool may provide an adapter interface to which different working ends can be attached to perform multiple different types of surgical maneuvers (e.g., the surgical tool may be able to receive one or more different tool bits, such that the surgical tool can drill, mill, cut, saw, ream, tap, etc. depending on the tool bit coupled with the surgical tool). The surgical tool may be operated autonomously or semi-autonomously. The navigation system 118 may track the pose (e.g., position and orientation) of and / or navigate the surgical tool.

[0074] Additionally or alternatively, the operative portion 180 may comprise a tool guide. The tool guide may provide a passive hole through which a surgical tool or component may pass to reach a surgical site. For example, the tool guide may be or comprise a hollow cylinder that can be aligned with a planned trajectory of a surgical tool. As a result, the guide provides a visual indicator to an operator (e.g., a surgeon) of the planned trajectory of the surgical tool. In some cases, the operative portion 180 comprising the tool guide may be attached to the robotic arm 116 and the robotic arm 116 may move such that the tool guide is positioned at the planned surgical entry point. Another robotic arm 116 with a surgical tool (e.g., a surgical drill) may then be positioned such that the surgical tool enters the surgical site through the tool guide.

[0075] The operative portion 180 may be controlled by a motor controller 176. The motor controller 176 may be connected to or otherwise communicate with one or more motors disposed in or connected to the end effector 140. The motor controller 176 may control the operation of the motors, such that the motor controller 176 controls movement of the end effector 140 and / or one or more components thereof such as the operative portion 180. The motor controller 176 may control the motors based on signals sent from the robot 114 or components thereof (e.g., the controller 128), the navigation system 118 or components thereof (e.g., the processor 104), the tracking system 132,A0012601 the tool changer 136, and / or the like. In one example, such as when the operative portion 180 comprises a surgical tool, the motor controller 176 may control one or more motors of the operative portion 180 to cause movement of the surgical tool, to turn the surgical tool on and off, combinations thereof, and / or the like.

[0076] The processor 168 may be similar to or the same as any processor discussed herein (e.g., the processor 104, processor 120, the processor 148, etc.). The processor 168 may be configured to execute instructions stored in the memory 172, which instructions may cause the processor 168 to send information stored in the memory 172 to one or more components of the system 100 (e.g., to the robot 114, to the navigation system 118, to the tracking system 132, to the tool changer 136, etc.). Additionally or alternatively, the instructions may cause the processor 168 write to or otherwise update information stored in the memory 172, such as to update information about the number of uses of the end effector 140, as discussed in further detail below.

[0077] Still with reference to Figs. IB and ID, the memory 172 may be similar to or the same as any memory discussed herein (e.g., the memory 122). The memory 172 may be or comprise RAM, DRAM, SDRAM, other solid-state memory, any memory described herein such as an EEPROM, or any other tangible, non-transitory memory for storing computer-readable data and / or instructions. The memory 106 may store information or data useful for completing, for example, one or more steps of the methods described herein, or of any other methods. In some cases, both the processor 168 and the stored on a printed circuit board disposed in the end effector 140. The memory 172 is reprogrammable memory, such that information stored in the memory 172 can be erased and reprogrammed. In one embodiment, the memory 172 may be unique to the end effector 140. In other words, each end effector 140 may have a separate memory 172 embedded in the end effector 140 and containing information unique to the end effector 140. The memory 172 comprises end effector type information 184, authentication information 188, calibration information 192, end effector usage information 194, and miscellaneous information 196.

[0078] The end effector type information 184 may indicate whether the end effector 140 is an active end effector (e.g., the operative portion 180 comprises an active surgical tool such as a surgical drill) or a passive end effector (e.g., the operative portion 180 comprises a passive surgical tool such as a tool guide). The end effector type information 184 may be accessed by the processor 168 and sent to the controller 128 of the robot 114. In some cases, the end effector type information 184 may be sent to the navigation system 118 to help the navigation system 118 track the end effector 140. In other words, the navigation system 118 may be able to better track the end effector 140 when the navigation system 118 has information about the type of end effector in use (e.g., aA0012601 passive end effector may not move as compared to an active end effector which may move). The controller 128 may render the end effector type information 184 to the user interface 110 to enable a user to view the end effector type information 184. The controller 128 may compare the end effector type information 184 to information stored in the database 130 to authenticate the end effector 140. For example, the surgical plan may call for the use of an active end effector capable of resecting anatomical tissue, and the end effector type information 184 may specify that the end effector 140 is an active end effector that includes a surgical drill. The controller 128 may receive the end effector type information 184 and, since the end effector type information 184 matches the end effector type required by the surgical plan, the controller 128 may determine that the end effector 140 connected to the robotic arm 116 is the correct end effector. As another example, the surgical plan may call for the use of an active surgical drill, but the end effector type information 184 may specify that the end effector 140 is a passive instrument (e.g., a tool guide) that cannot resect anatomical tissue. As a result, when the controller 128 compares the end effector type information 184 to the stored data, the controller 128 may determine that the end effector 140 is not the correct end effector for the current step of the procedure. In such examples, the controller 128 may render a warning (e.g., a flashing light) to the display to notify the user that the incorrect end effector has been attached. Additionally or alternatively, the controller 128 may disable use of the robotic arm 116 and / or components thereof until the improper end effector 140 is removed or until the appropriate end effector 140 is attached.

[0079] The authentication information 188 may comprise information that enables the system 100 or components thereof (e.g., the processor 120 of the robot 114) to authenticate the end effector 140. The end effector type information 184 may be or comprise information associated with the manufacturing source, date of manufacturing, lot number, model number, serial number, recommended operating settings, operating parameters, combinations thereof, and / or the like. In some embodiments, the authentication information 188 may be accessed by the processor 168 and sent to the controller 128 of the robot 114. The controller 128 may compare the authentication information 188 to information stored in the database 130 to authenticate the end effector 140. For example, the surgical plan for a surgical procedure may call for the use of an end effector manufactured by a first manufacturer, and the authentication information 188 may specify that the end effector 140 was manufactured by the first manufacturer. The controller 128 may receive the authentication information 188 and, since the authentication information 188 matches the surgical plan, the controller 128 may determine that the end effector 140 connected to the robotic arm 116 is an acceptable end effector for performing the surgical procedure. In some cases, the controller 128 may be able to control the end effector 140 once the end effector 140 has been authenticated. AsA0012601 another example, the surgical plan may call for the use of an end effector manufactured by the first manufacturer, but the authentication information 188 may specify that the end effector 140 was manufactured by a second, different manufacturer. As a result, when the controller 128 compares the authentication information 188 to the stored data, the controller 128 may determine that the end effector 140 is not acceptable to perform the current step of the procedure. In such examples, the controller 128 may render a warning (e.g., a flashing light) to the display to notify the user that the incorrect end effector has been attached. Additionally or alternatively, the controller 128 may disable use of the robotic arm 116 and / or components thereof until the improper end effector 140 is removed or until the appropriate end effector 140 is attached.

[0080] The calibration information 192 may comprise information about the dimensions of the end effector 140 and / or components thereof (e.g., the operative portion 180). The dimensions may be based on one or more measurements of the end effector 140 generated with one or more measurement systems. For example, the dimensions of the end effector 140 may be generated using a CMM. The CMM may capture the geometry of the end effector 140 based on sensing of discrete points on the surface of the end effector 140. In some embodiments, the measurements of the end effector 140 may be stored as the calibration information 192 in the memory 172. The calibration information 192 may be accessed by the processor 168 and sent to the controller 128. The processor 168 may send the information once the end effector 140 is coupled to the robotic arm 116 (e.g., via the tool changer 136). The controller 128 may receive the calibration information 192 and use the calibration information 192 along with the known pose of the robotic arm 116 to register the end effector 140 to the robot 114. The controller 128 may additionally or alternatively register the end effector 140 to any other coordinate system, and send such information to the navigation system 118 to enable the navigation system 118 to track the pose of the end effector 140.

[0081] The end effector usage information 194 may comprise information about a number of times the end effector 140 has been used. For example, the end effector usage information 194 may comprise an integer number representative of the number of times the end effector 140 has connected to a robotic arm 116 and / or a component thereof (e.g., the tool changer 136) and / or the number of times the end effector 140 has been used in a surgery or surgical procedure. In some embodiments, the end effector usage information 194 may be updated and saved to the memory 172 once the end effector 140 has been connected to the tool changer 136. For example, the end effector usage information 194 may indicate that the end effector 140 has been used three times. When the robotic arm 116 moves to the tool stand and the end effector 140 is coupled with the distal end of the tool changer 136, or when the user manually attaches the end effector 140 to the tool changer 136,A0012601 the processor 168 may access the memory 172 and update the end effector usage information 194 to indicate that the end effector 140 has been used four times. Additionally or alternatively, the processor 168 may send the end effector usage information 194 to one or more components of the system 100, such as to the user interface 110 so that the end effector usage information 194 can be rendered to a display and reviewed by a user (e.g., a physician, a member of surgical staff, etc.). In some embodiments, the end effector usage information 194 may be updated by the processor 168 after the end effector 140 has been used and returned to the tool stand. In other words, the memory 172 is updated after the end effector 140 has been used and the surgical procedure requiring the end effector 140 has concluded.

[0082] In some embodiments, the processor 168 may access the end effector usage information 194 and send the end effector usage information 194 to the controller 128, and the controller 128 may determine whether the end effector 140 has exceeded a predetermined number of uses. The predetermined number of uses may be or comprise a threshold value stored, for example, in the database 130. When the number of uses of the end effector 140 meets or exceeds the threshold value, the controller 128 may disable use of the end effector 140 such as by preventing the operative portion 180 of the end effector 140 from receiving power. In some embodiments, the controller 128 may cause the processor 168 to write instructions to the memory 172 that specify that the end effector 140 is not to be used again. Additionally or alternatively, the controller 128 may render a warning to the user interface 110 that notifies the user that the end effector 140 has exceeded the threshold number of uses. The threshold number of uses may be based on the specifications of the surgery or surgical procedure, the surgical plan, surgeon preference, combinations thereof, and / or the like.

[0083] The miscellaneous information 196 may comprise any other useful information associated with the end effector 140 and / or components thereof. The miscellaneous information 196 may comprise historical data associated with the end effector 140, such as the dates on which the end effector 140 was used, overall time of use of the end effector 140, combinations thereof, and / or the like.

[0084] As may be appreciated and as described in more detail below with reference to other figures, some or all of the information 184, 188, 192, 194, and 196 contained in the memory 172 may be used to identify the end effector 140 for the sake of energizing selected portions (e.g., conductive pins) of an electrical interface of the tool changer 136 included with the interfaces 164. Stated another way, an electrical interface 164 of a tool changer 136 may comprise a plurality of conductive pins or other electrical connectors and different end effectors 140 may utilize differentA0012601 ones of the pins or connectors. The information in memory 172 may be used to identify the end effector 140 currently connected to the tool changer 136 so that the tracking system 132 sends power and / or data (e.g., control signals) to the appropriate pins or connectors. For example, the end effector type information 184 may be used to identify the currently connected end effector 140 as a particular model of a drill that utilizes a subset of the electrical pins on the tool changer 136 so that power and / or control signals are sent from the tracking system 132 to the proper pins of the tool changer 136 for the purpose of controlling the end effector 140.

[0085] It is to be understood that the above discussion of the memory 172 and the elements thereof (e.g., the end effector type information 184, the authentication information 188, etc.) is not limiting to the end effector 140, and other components of the system 100 may have such information stored in an erasable and programmable memory that is unique to that component. For example, the memory 152 of the tracking system 132 may comprise an EEPROM or any similar erasable and programmable memory that stores information about the tracking system 132.

[0086] The system 100 or similar systems may be used, for example, to carry out one or more aspects of the methods described herein. The system 100 or similar systems may also be used for other purposes.

[0087] Figs. 2A and 2B illustrate different views of a tool changer 136 according to at least one embodiment of the present disclosure. Fig. 2C illustrates a distal end view of a tracking system 132 according to at least one embodiment of the present disclosure. In particular, Fig. 2 A illustrates an example distal end view of a tool changer 136 that electrically and mechanically connects to an end effector 140 (not shown) via corresponding interfaces. Meanwhile Fig. 2B illustrates an example proximal end view of a tool changer 136, which may face the distal end of the tracking system 132 in Fig. 2C when connected to the tracking system 132. The interfaces of the tool changer 136 are described in more detail below with reference to Figs. 2A-2C but should generally be understood to include respective electrical connections and a first type of mechanical connection to the tracking system 132 (e.g., via one or more screws or threaded bolts) and a second type of mechanical connection to the end effector (e.g., a locking kinematic connection). One may refer to US Patent Application Nos. US 17 / 357,649 (US Publication No. 2022 / 0409303) and US 17,357 / 647 (US Publication No. 2022 / 0409304), both incorporated herein by reference, filed on June 24, 2021, and entitled “Interchangeable End Effector and Sterile Barrier” for additional detail regarding connections between a tool changer and an end effector and an add-on, such as the tracking system 132.A0012601

[0088] With reference to Figs. 2A and 2B, the tool changer 136 includes a stationary portion 200 and a movable portion 204 that rotates relative to the stationary portion 200 in the directions illustrated with dashed bi-directional arrows D. The stationary portion 200 may include a lockunlock indicator 208 and the movable portion 204 may include a corresponding mark or indicator 212 used to indicate whether an end effector 140 is locked to the tool changer 136. For example, starting in an unlocked state as indicated by indicators 208 and 212, a user may place an end effector 140 (not shown) into an interior 218 of the tool changer and manually rotate the movable portion 204 with the aid of a protrusion 216 relative to the stationary portion 200 in a counter-clockwise direction (or clockwise direction if designed as such) to lock the end effector 140 to the stationary portion 200. Four total protrusions 216 are shown, but the number of protrusions could be more or fewer, and in some scenarios, could be zero in which case the outer surface of the movable portion 204 may be textured. To unlock the end effector 140 from the stationary portion 200, the user manually rotates the movable portion 204 clockwise until the indicator 212 reaches the unlock portion of indicator 208. In some examples, locking the end effector 140 to the tool changer 136 also causes the end effector 140 to make electrical contact with the tool changer 136 by means of a mechanism that converts the rotational movement of the movable portion 204 into translational movement of the end effector 140. Conversely, unlocking the end effector 140 from the tool changer 136 may cause or allow the end effector 140 to move away from the tool changer 136 so that electrical contact does not exist.

[0089] In some cases, the mechanism employed for a locking effect comprises a mechanism described in the above- referenced US patent applications and / or any other suitable locking mechanism. As described in these documents, protrusions 220a, 220b, 220c, and / or 220d may facilitate alignment, locking, and / or restriction of movement between the tool changer 136 and an end effector 140. In some examples, protrusions 220c are for a kinematic connection between the tool changer 136 and the end effector 140.

[0090] As described in more detail below, the connection between the tool changer 136 and the tracking system 132 may be embodied by one or more mechanical connectors that are engaged via an applied rotational force that can be converted to a torque measurement based output of the FT sensor 158. For example, the tool changer 136 comprises one or more screw connections 222, shown in Figs. 2A and 2B as 222a, 222b, and 222c (222c not shown in Fig. 2A due to the view). When the tool changer 136 and tracking system 132 are connected to one another, each screw connection 222a, 222b, and 222c may comprise a threaded screw or bolt inserted into the interior 218 of the distal end of the tool changer 136 in Fig. 2A so as to penetrate through the proximal end of the tool changerA0012601136 in Fig. 2B and into a corresponding threaded receiver portion 224a, 224b, and 224c of the tracking system 132 in Fig. 2C.

[0091] As shown in Figs. 2A-2C, electrical connection between the tool changer 136 and the tracking system 132 and end effector 140 may be achieved through electrical connectors of the tool changer 136 and an electrical connector of the tracking system 132. In the non-limiting example shown in Figs. 2A and 2B, the electrical connectors of the tool changer 136 comprise a plurality of conductive pins 226a and 226b, and the electrical connector of the tracking system 132 comprises conductive pads 228 that correspond to each conductive pin 226b. Here, it should be appreciated that Figs. 2A, 2B, and 2C do not necessarily show a one-to-one correspondence between the pins at the distal and proximal ends of the tool changer 136 and / or between the pins of the tool changer 136 and conductive pads 228 of the tracking system 132, but that such a one-to-one correspondence may exist in practice. Stated another way, each pin 226a at a distal end of the tool changer 136 may electrically connect to a corresponding pin 226b at the proximal end of the tool changer 136 and a corresponding conductive pad 228 of the tracking system 132 through a pad internal to the tool changer, and each pin 226b may electrically connect to a corresponding conductive pad 228 of the tracking system 132. In some cases, corresponding pins 226a and 226b are aligned with one another so as to have a same central longitudinal axis.

[0092] In some examples, the pins 226a and 226b are spring loaded so as to have a compressed or pushed-in state and a decompressed or protruded state. For example, when the tool changer 136 and the tracking system 132 are already connected, the pins 226a and 226b may be in a compressed state and in electrical contact with corresponding conductive pads (not shown) internal to the tool changer 136 and positioned between ends of corresponding pins 226a and 226b. Meanwhile, the pins 226b are in a decompressed state when the tool changer 136 is detached from or not secured to the tracking system 132. When an end effector 140 is attached and / or locked to the tool changer 136, spring-loaded pins 226a may be pushed into electrical contact with the conductive pads (not shown) internal to the tool changer 136. The pins 226b may be in a decompressed state when the end effector 140 is detached from or not locked to the tool changer 136. In this case, the pins 226a retract from the conductive pads internal to the tool changer 136 so as to not to be in electrical contact. In some examples, at least some of the pins 226a and / or some of the pins 226b are not spring-loaded and are instead non-retractable conductive posts designed to make electrical contact with connections (which may be spring-loaded or not) on the end effector 140 and / or the tracking system 132. For example, pins 226b at the proximal end of the tool changer 136 are not spring loaded, andA0012601 instead have lengths so as to be in constant electrical contact with pads 228 when the tool changer 136 is connected to the tracking system 132.

[0093] The above discussion describes a pin 226a as being separate from a pin 226b and electrically connectable to one another through a corresponding conductive pad internal to the tool changer 136. However, in some examples, a pin 226a and a pin 226b form a unitary component (i.e., a single pin) which passes through the tool changer 136 from the distal end to the proximal end. In this case, both ends of the pin may have the same or similar spring-loaded functionality and compressed / decompressed states described so that the ends are compressed inward toward a center of the tool changer 136 in a compressed state and are allowed to decompress by extending away from the center of the tool changer 136 in a decompressed state. In some examples, the pin may comprise a conductive pad or part located between the ends which serves the same purpose as the above-described conductive pads internal to the tool changer 136. Here, the pin conducts electricity from one end to the other only when both ends are in the compressed state. Thus, a conductive part of one end of the pin may be separated from a conductive part of the other end of the pin by an insulator when either end is in the decompressed state. For example, an insulative middle section of the pin may separate the two conductive ends. The insulative middle section may be secured within the tool changer 136 and may be surrounded by or house a conductive pad that enables electrical connection when both ends are in the compressed state (i.e., when the tool changer 136 is connected to the end effector 140 and the tracking system 132 to push each end of the pin into contact with the conductive pad).

[0094] Referring to Figs. 2B and 2C, the proximal end of the tool changer 136 may include one or more alignment aids, such as protrusions 230a and 230b integrated with respective connections 222a and 222b, and the tracking system 132 may include corresponding recesses 232a and 232b. The protrusions and recesses may assist with aligning the tool changer 136 and the tracking system 132 for proper connection and with ensuring accuracy of the system by providing an accurate and repeatable connection. In Fig. 2B, a protrusion and a corresponding recess is not included for connection 222c. In at least one example, a user inserts each protrusion 230a, 230b into a corresponding recess 232a, 232b and then secures the tool changer 136 to the tracking system 132 via the one or more screw connections 222 and corresponding threads 224. The protrusions 230a and 230b and corresponding recesses 232a and 232b may be shaped differently so as to provide additional assurance that the tool changer 136 is properly aligned to the tracking system 132.

[0095] With reference to Fig. 2C, the tracking system 132 may comprise a mesa structure 234, threaded receiver portions 224, and pads 228. The mesa structure 234 may protrude from a recessedA0012601 surface 236 that functions as a cover for other components of the tracking system 132. The tracking system 132 may further comprise an FT sensor 158 which, when connected to the tool changer 136 and the robotic arm 116, is in force-transmitting contact with the robotic arm 116 and the tool changer 136. The FT sensor 158 may be an internal component of the tracking system 132 not visible in Fig. 2C, but with a “tool side” of the FT sensor 158 being in force-transmitting contact with (e.g., attached to) a support portion 238 and with the “robot side” of the FT sensor 158 being attached to a chassis 250 of the tracking system 132 connected to the robotic arm 116. Notably, the support portion 238 is a “floating” component that is allowed to move freely relative to the chassis 250 of the tracking system 132 to enable accurate readings from the FT sensor 158. Stated another way, there is not a direct connection or attachment between the chassis 250 and the support portion 238. In general, the FT sensor 158 is configured to generate sensor data indicative of rotational and / or translational (compressive and tensile) forces experienced by the elements of the system 100 while operating the end effector during a surgical procedure. That is, the FT sensor 158 is capable of measuring moments / torques in all axes (X, Y, and Z) and forces (compressive and tensile) in all axes (X, Y, and Z), which may be used to trigger one or more alerts, such a visual alert by an output device 159 embodiment by one or more visible-light LEDs in Fig. 2C.

[0096] In some examples and as discussed in more detail below, output of the FT sensor 158 may be used to monitor kerf during a procedure that removes a portion of an anatomical element of a patient.

[0097] Fig. 3 illustrates a method 300 according to at least one embodiment of the present disclosure. The method 300 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by at least one processor. The at least one processor may be the same as or similar to the processor(s) described above. The at least one processor may be part of a robot (such as a robot 114) or part of another system (such as a tracking system 132). A processor other than any processor described herein may also be used to execute the method 300. The at least one processor may perform the method 300 by executing instructions stored in a memory described herein. The instructions stored in memory and executed by the processor may cause the processor to execute one or more steps of a function as shown in method 300.

[0098] Operation 304 includes monitoring kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor 158 in force- transmitting contact with a robotic arm 116 and an end effector 140 and / or the surgical tool. Kerf may refer to the width of a cut in the anatomical element as a result of drilling, cutting, milling, sawing, and / or reaming. Thus, the surgical tool may correspond to an operative portion 180 of an end effector 140A0012601 and may include a tool for drilling, cutting, milling, sawing, and / or reaming the anatomical element, which may include bone (e.g., a vertebra) or tissue. In some examples, the surgical tool comprises a laser or other light source for ablating or cutting hard and / or soft tissue. The FT sensor 158 may be included with a tracking system 132 that facilitates tracking of the robotic arm 116 within a coordinate system, such as coordinate system formed by navigation system 118. Monitoring kerf may be performed in real-time throughout or during at least part of the removal of the portion of the anatomical element for the sake of ensuring that the kerf remains within acceptable limits as the overall system vibrates due to internal and / or external causes, such as operation of the surgical tool, movement of the robotic arm, accidental collision with the robot 114, and / or the like.

[0099] As discussed herein, real-time monitoring of the kerf during removal of the portion of the anatomical element may include repeatedly measuring or estimating the kerf based on output of the FT sensor 158 as a robotic arm 116 moves along a path to remove the portion of the anatomical element. As such, it may be said that the kerf is indirectly determined in that there is not a physical measurement of the width of the cut but an indirect measurement derived from output of the FT sensor 158.

[0100] Example embodiments provide at least two ways to estimate or determine kerf during the monitoring step 304. In one or both scenarios, step 304 may include one or more steps to account for the circumstance that output of the FT sensor 158 is affected by one or more elements of the system positioned between the FT sensor 158 and the tip of the surgical tool. Such elements may include the surgical tool itself, the end effector 140, the tool changer 136, and / or any robotic arm or other joints which may be positioned upstream of the FT sensor 158. Accordingly, step 304 may include correcting the output of the FT sensor 158 to account for effects on the output caused by elements being positioned between the force-torque sensor and the anatomical element, including the surgical tool and the end effector, and then determining the kerf using the corrected output. Correcting the output of the FT sensor 158 may comprise performing one or more calibration operations that match known kerfs (i.e., known cut widths) to measurements taken by the FT sensor 158 during formation of the known kerfs.

[0101] In any case, a first method for determining kerf in step 304 is described with reference to Fig. 4A and method 400. The method 400 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by at least one processor. The at least one processor may be the same as or similar to the processor(s) described above. The at least one processor may be part of a robot (such as a robot 114) or part of another system (such as a tracking system 132). A processor other than any processor described herein may also be used to execute the method 400. The at leastA0012601 one processor may perform the method 400 by executing instructions stored in a memory described herein. The instructions stored in memory and executed by the processor may cause the processor to execute one or more steps of a function as shown in method 400.

[0102] As shown in Fig. 4 A, the method 400 includes a step 404 of measuring acceleration at one or more locations of interest with the FT sensor 158 and in real time or near real time. For example, step 404 may include measuring, based on the output of the force-torque sensor 158, acceleration at the surgical tool, for example, at the tip of the surgical tool. In at least one example, acceleration is measured in a direction that is perpendicular to movement of the robotic arm 116 during removal of the portion of the anatomical element. For example, if the robotic arm 116 is moving in a y- direction, then the signals of interest output from the FT sensor 158 to measure acceleration are signals indicative of surgical tool movement in an x-direction for kerf or a z-direction (depth direction) for cut depth. As may be appreciated, output of the FT sensor 158 that is not indicative of movement in the x-direction and / or z-direction may be discarded or ignored.

[0103] In step 404, kerf is continuously determined or calculated based on the measured acceleration, for example, by performing a double integration of the measured acceleration in the x- direction to arrive at a displacement value which corresponds to the kerf because displacement(t) = \velociiy(i)di = J ( \acceleration(i)di)di. If measuring cut depth, then step 404 may perform the double integration on the measured acceleration in the z-direction, where the displacement value corresponds to cut depth.

[0104] As shown in Fig. 4A, the method may proceed from step 408 to step 308 in Fig. 3, which is described in more detail below following the description of a second method for performing step 304.

[0105] A second method for determining or monitoring kerf in step 304 which may be performed in addition to or as an alternative to the first method is described with reference to Fig. 4B and method 500. The method 500 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by at least one processor. The at least one processor may be the same as or similar to the processor(s) described above. The at least one processor may be part of a robot (such as a robot 114) or part of another system (such as a tracking system 132). A processor other than any processor described herein may also be used to execute the method 500. The at least one processor may perform the method 500 by executing instructions stored in a memory described herein. The instructions stored in memory and executed by the processor may cause the processor to execute one or more steps of a function as shown in method 500.A0012601

[0106] As shown in Fig. 4B, the method 500 includes a step 504 of generating a lookup table or other suitable database of information that matches a plurality of kerfs to a plurality of variables, where such variables correspond to possible system conditions for performing a bone removal procedure. The plurality of kerfs and plurality of variables may be collected prior to step 304 in a calibration or preparation step for the system.

[0107] In some examples, the plurality of variables include one or more robotic system variables and one or more anatomical element variables. The one or more robotic system variables may include a load on the end effector 140, direction of the load on the end effector 140, pose of the robotic arm 116, movement speed of the robotic arm 116 during removal of the portion of the anatomical element, operating parameters of the surgical tool (e.g., operating frequency or speed), or any combination thereof. Both the load on the surgical tool and the direction of the load on the surgical tool may be determined from output of the FT sensor 158, which output may be translated (e.g., by processor 148) from a raw output that includes forces not relevant to load or load direction into a signal or signals that are indicative of load and load direction of the surgical tool.

[0108] Meanwhile, the one or more anatomical element variables may include a depth of the removed portion of the anatomical element (e.g., cut depth), a density of the anatomical element (e.g., bone density), a size of the anatomical element, a shape of the anatomical element, a type of the anatomical element (e.g., vertebra, vertebra at a particular level - Ti l vs. T12, patella, skull, etc.), or any combination thereof. The anatomical element variables may be specific to the patient based on past measurements of those variables for the patient. However, example embodiments are not limited thereto, and the anatomical element variables may be selected to match those of an average patient.

[0109] An example lookup table for determining kerf that may be generated and stored in memory in step 504 is shown below in Table 1.Table 1A0012601

[0110] As may be appreciated, Table 1 is merely an example and may be modified and expanded upon in a suitable manner. For example, more or fewer arm poses (e.g., P3, P4... Pn), arm speeds (e.g., 4mm / s, 5mm / s...Nmm / s), cutting speeds (e.g., S3, S4... Sn), cut depths (e.g., CD2, CD3... CDn), loads (e.g., L3, L4...Ln), load directions (e.g., DL3, DL4...DLn), and types of anatomical elements (e.g., A2, A3... An) may be included.

[0111] The method 500 may further include monitoring real time system conditions during a bone removal procedure in step 508, and determining or estimating real time kerf based on the system conditions and the lookup table that matches a plurality of kerfs to a plurality of variables in step 512. The system conditions may be determined in real time with suitable sensors that sense the variables used for the table. Such sensors may already be included with off-the-shelf robotic arms and other elements forming the system 100. As may be appreciated, steps 508 and 512 may be performed substantially simultaneously to continuously match the system conditions to variables in the table, where the system conditions include robotic system and / or anatomical element values that have corresponding values in the table. Stated another way, in Table 1, kerfs are measured (i.e., known by physical measurement or other suitable accurate measurement) under various different robotic system and anatomical element variables such that steps 508 and 512, at a time tl, can include consulting the table to match the system conditions of the bone removal procedure at time tl to a row of variables in the table to arrive at a real-time kerf value for time tl . For example, step 512 includes selecting one of the plurality of kerfs from the table as the real-time kerf measurement when there is a matching of system conditions to variables in the table. Retrieving kerf values from the table in step 512 may be repeated at times t2, t3...tn throughout step 512. The frequency of retrieval may vary according to preference or design constraints but should be performed often enough to safely avoid exceeding the threshold discussed below with reference to step 308 (e.g., every 100ms).

[0112] Here, it should be understood that in some scenarios the table may not contain a row of variables that exactly match the conditions of the bone removal procedure. In this case, a rounding approach may be used. For example, matching values of conditions to values of variables mayA0012601 involve searching the table to select the variables nearest in value to respective values of the conditions and considering the selected variables as ones that match the values of the condition. Additionally or alternatively, if values of the conditions do not exactly match values of variables in the table, interpolation and / or extrapolation may be used to create new data points which may be added to the table. In an interpolation example, the conditions of the bone removal procedure may fall between two sets (e.g., rows) of variables in the table in which case an interpolation algorithm may be used to determine a kerf value that falls between the kerf values associated with the two sets of variables. In an extrapolation example, the conditions of the bone removal procedure may fall outside the sets of variables within the table in which case an extrapolation algorithm may determine one or more trends within the table and apply the trend(s) to the conditions of the removal procedure to arrive at a kerf value. In some examples, the surgeon or system may be prompted to physically or directly measure the kerf and / or cut depth following a procedure for the sake of adding another entry (e.g., row) to the table that associates the measured kerf and / or cut depth to the conditions just used for the procedure.

[0113] As shown in Fig. 4B, the method may proceed from step 512 to step 308 in Fig. 3, described in more detail below.

[0114] With reference back to Fig. 3, operation 308 includes determining that the monitored kerf in operation 304 (using method 400 and / or 500) reaches a threshold. Operation 308 may be performed substantially simultaneously with operation 304 and may include continuously determining whether the kerf monitored in step 304 reaches the threshold. If so, the method proceeds to operation 312, but if not, the method continues to determine whether the monitored kerf reaches the threshold until the bone removal procedure terminates.

[0115] As noted above, either the double integration method 400 or the lookup table method 500 can be used to determine real time kerf in the monitoring step 304. In some examples, both methods are performed simultaneously as a means to provide an extra layer of confidence that the estimated kerf is accurate and suitable for comparison to the threshold in step 308. If each method produces a different estimated kerf at a particular point in time, the different kerfs may be averaged with the result being compared to the threshold in operation 308. In some examples, one of the methods (e.g., the double integration method) may be known to be more accurate than the other method (e.g., the lookup table method) as determined through past procedures, and so the kerf value produced by the more accurate method may be weighted more heavily when determining the average than the kerf value produced by the less accurate method. Stated another way, the kerf used for comparison to the threshold in step 308 is computed as a weighted average. In yet other examples, the kerf value fromA0012601 the less accurate method is discarded and not used at all for the comparison to the threshold in step 308.

[0116] In some examples, step 304 determines a difference between the kerf value produced for each method at various points in time and the system may issue an audio and / or visual alert or warning te the surgeon when the difference is larger than a suitable threshold. The difference between kerf values produced by each method being larger than a threshold difference may indicate a malfunction with hardware and / or software within one of the methods used to determine the kerf value. At that point, the surgeon can provide input to a user interface to indicate that the system should discard the kerf value from the malfunctioning method and use the kerf value from the normally functioning method for comparison to the threshold in step 308.

[0117] As noted herein, vibrations of the overall system (e.g., vibrations caused by cart movement, robotic arm movement, surgical tool operation, and / or accidental impacts with the cart, arm, and / or tool, etc.), especially vibrations that occur at the resonant frequency of the system, may cause kerf to undesirably increase, leading to potentially unsafe cutting conditions near damage sensitive areas such as nerves or the spinal cord. The threshold in step 308 then, may be selected as a kerf that is considered safe for the particular removal procedure. For example, if a kerf of an oscillating drill under normal conditions (e.g., no vibration or normal vibration) is 4mm and a damage sensitive area is at minimum 6mm away from a part of the cut path, the threshold in step 308 may be selected as 4.5mm. If the double integration and / or the lookup table method above determines that the kerf of the oscillating drill reaches 4.5mm or more, then method proceeds to operation 312.

[0118] In some examples, step 308 includes selecting the threshold based on a type of procedure for removing the portion of the anatomical element, a type of anatomical element, surgeon input, or any combination thereof. At least one embodiment includes consulting a table similar to step 204. For example, different thresholds may exist for different types of procedures and anatomical elements. Thus, one example of a table for use in step 308 includes a listing that matches each type of procedure and / or anatomical element to a threshold kerf. Obtaining a threshold kerf may include, prior to the removal procedure, automatically selecting a threshold kerf from the table based on the type of procedure and / or anatomical element being operated on and then presenting the selected threshold kerf to the surgeon as a proposed threshold kerf that the surgeon can modify or accept through a user interface (e.g., user interface 110) as the threshold for use during the removal procedure. Alternatively, the surgeon may input the kerf to the user interface prior to the procedure.A0012601

[0119] In some examples, the threshold is automatically adjusted upward and / or downward during the removal procedure as the robotic arm 116 moves along a cutting path to account for varying tolerances. For example, as the robotic arm 116 moves the surgical tool further away from a damage sensitive area, the threshold may be automatically adjusted upward (e.g., to 5mm in the example above). Similarly, as the robotic arm 116 moves the surgical tool closer to a damage sensitive area, the threshold may automatically adjust downward (e.g., to 4.25mm in the example above). Automatic adjustment of the threshold upward and downward may occur in a step-wise or graded fashion as the navigation system 118 determines surgical tool to cross different distance thresholds relative to a location of a damage sensitive area.

[0120] In step 308, upon determining that a kerf value from step 304 exceeds the threshold at an instant time, the method proceeds to step 312 to output one or more signals in response thereto. Stated another way, step 312 includes outputting one or more signals in response to determining that the monitored kerf has reached the threshold. The one or more signals may be output by processor 148 (or another processor in the system such as one that also carries out steps 304 and 308) to one or more other elements of the system to carry out a safety measure related to the removal procedure. For example, the one or more signals may cause the tracking system 132 to issue an audio and / or visual alert, for example, through output device(s) 159. In some examples, the one or more signals cause movement of the robotic arm 116 to stop so that the surgical tool’s cutting path is temporarily halted. In some examples, the one or more signals cause the surgical tool to cease operation, which may include cutting power to the operative portion 180. In some cases, the one or more signals cause adjustment to an operating parameter of the surgical tool and / or the robotic arm with the adjustment being intended to bring the monitored kerf back below the threshold. Such adjustment may include reducing rotation or oscillating speed of the tool, reducing robotic arm speed, raising the surgical tool from the cutting surface, and / or the like.

[0121] Here, it should be appreciated that the method 300 may include comparing the monitored kerf in step 304 to multiple thresholds in step 308, where each threshold is selected in accordance with the discussion above. In this case, outputting the one or more signals in operation 312 may cause different effects as different thresholds are reached, such that the monitored kerf reaching progressively higher threshold kerfs results in more drastic safety actions. For example, the monitored kerf from step 304 reaching a first threshold (e.g., 4.5mm) may result in the one or more signals causing an alert or warning for the surgeon. The kerf reaching a second threshold (e.g., 4.75mm), higher than the first threshold, may result in the one or more signals of step 312 causing adjustment to elements known to reduce kerf to bring the monitored kerf back below the secondA0012601 threshold, such as adjustment to an operating parameter of the surgical tool and / or adjustment to arm speed (e.g., reduction of surgical tool rotation or oscillation frequency and / or reduction of arm speed). Should the monitored kerf subsequently reach a third threshold (e.g., 5mm), higher than the second threshold, the one or more signals may cause the robotic arm and / or the surgical tool to cease operation / movement. Operation of the robotic arm and / or the surgical tool may only restart when specifically approved by the surgeon, for example, through input to the user interface.

[0122] The present disclosure encompasses methods with fewer than all of the steps identified in Fig. 3 (and the corresponding description of the method 300), as well as methods that include additional steps beyond those identified in Fig. 3 (and the corresponding description of the method 300). The present disclosure also encompasses methods that comprise one or more steps from one method described herein, and one or more steps from another method described herein.

[0123] The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description, for example, various features of the disclosure are grouped together in one or more aspects, embodiments, and / or configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and / or configurations of the disclosure may be combined in alternate aspects, embodiments, and / or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects he in less than all features of a single foregoing disclosed aspect, embodiment, and / or configuration. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0124] Moreover, though the foregoing has included description of one or more aspects, embodiments, and / or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, embodiments, and / or configurations to the extent permitted, including alternate, interchangeable and / or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and / or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

[0125] Aspects of the present disclosure include:

[0126] The techniques of this disclosure may also be described in the following examples:A0012601

[0127] Example 1. A robotic surgical system, comprising: a tracking system configured to facilitate tracking of a robotic arm within a coordinate system, the tracking system comprising a force-torque sensor configured to be in force transmitting contact with the robotic arm and an end effector that supports a surgical tool for removing a portion of an anatomical element of a patient; and at least one processor configured to: monitor kerf of the removed portion of the anatomical element based on output of the force-torque sensor; determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

[0128] Example 2. The robotic surgical system of example 1, wherein the at least one processor is configured to monitor the kerf by: correcting the output of the force-torque sensor to account for effects on the output caused by elements being positioned between the force-torque sensor and the anatomical element, including the surgical tool and the end effector; and determining the kerf using the corrected output.

[0129] Example 3. The robotic surgical system of one or more of examples 1 to 2, wherein the at least one processor is configured to monitor kerf by: measuring, based on the output of the forcetorque sensor, acceleration at the surgical tool in a direction that is perpendicular to movement of the robotic arm during removal of the portion of the anatomical element; and determining the kerf based on the measured acceleration.

[0130] Example 4. The robotic surgical system of one or more of examples 1 to 3, wherein the at least one processor is configured to perform a double integration of the measured acceleration to arrive at a displacement value which corresponds to the kerf.

[0131] Example 5. The robotic surgical system of one or more of examples 1 to 4, wherein the at least one processor is configured to monitor kerf by: determining the kerf from a lookup table that matches a plurality of kerfs to a plurality of variables.

[0132] Example 6. The robotic surgical system of one or more of examples 1 to 5, wherein the plurality of variables include one or more robotic system variables and one or more anatomical element variables.

[0133] Example 7. The robotic surgical system of claim one or more of examples 1 to 6, wherein the one or more robotic system variables include at least one of a load on the end effector, direction of the load on the end effector, pose of the robotic arm, movement speed of the robotic arm during removal of the portion of the anatomical element, or operating parameters of the surgical tool.A0012601

[0134] Example 8. The robotic surgical system of one or more of examples 1 to 7, wherein the one or more anatomical element variables include at least one of a depth of the removed portion of the anatomical element, a density of the anatomical element, a size of the anatomical element, a shape of the anatomical element, or a type of the anatomical element.

[0135] Example 9. The robotic surgical system of one or more of examples 1 to 8, wherein the at least one processor is configured to select the threshold based on one or more of a type of procedure for removing the portion of the anatomical element, a type of anatomical element, or surgeon input.

[0136] Example 10. The robotic surgical system of one or more of examples 1 to 9, wherein the one or more signals cause the tracking system to issue an audio and / or visual alert.

[0137] Example 11. The robotic surgical system of one or more of examples 1 to 10, wherein the one or more signals cause movement of the robotic arm to stop.

[0138] Example 12. The robotic surgical system of one or more of examples 1 to 11, wherein the one or more signals cause the surgical tool to cease operation.

[0139] Example 13. The robotic surgical system of one or more of examples 1 to 12, wherein the one or more signals cause adjustment to an operating parameter of the surgical tool.

[0140] Example 14. The robotic surgical system of one or more of examples 1 to 13, wherein the force-torque sensor has six degrees of freedom.

[0141] Example 15. The robotic surgical system of one or more of examples 1 to 14, further comprising: the end effector; and the surgical tool.

[0142] Example 16. The robotic surgical system of example 15, wherein the surgical tool is integrated with the end effector as an active end effector.

[0143] Example 17. A device, comprising: at least one processor; and memory comprising instructions that when executed by the processor, cause the processor to: monitor kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor in force-transmitting contact with a robotic arm and the surgical tool; determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

[0144] Example 18. The device of example 17, wherein the instructions include instructions that when executed by the at least one processor, cause the at least one processor to monitor kerf by: measuring, based on the output of the force-torque sensor, acceleration at the surgical tool in a direction that is perpendicular to movement of the robotic arm during removal of the portion of the anatomical element; and performing a double integration of the measured acceleration to arrive at a displacement value which corresponds to the kerf.A0012601

[0145] Example 19. The device of one or more of examples 17 to 18, wherein the instructions include instructions that when executed by the at least one processor, cause the at least one processor to monitor kerf by: determining the kerf from a lookup table that matches a plurality of kerfs to a plurality of variables, wherein the plurality of variables include one or more robotic system variables and one or more anatomical element variables.

[0146] Example 20. A method, comprising: monitoring kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor in forcetransmitting contact with a robotic arm and the surgical tool; determining that the monitored kerf reaches a threshold; and outputting one or more signals in response to determining that the monitored kerf has reached the threshold.

Claims

A0012601CLAIMSWhat is claimed is:

1. A robotic surgical system, comprising: a tracking system configured to facilitate tracking of a robotic arm within a coordinate system, the tracking system comprising a force-torque sensor configured to be in force transmitting contact with the robotic arm and an end effector that supports a surgical tool for removing a portion of an anatomical element of a patient; and at least one processor configured to: monitor kerf of the removed portion of the anatomical element based on output of the force-torque sensor; determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

2. The robotic surgical system of claim 1, wherein the at least one processor is configured to monitor the kerf by: correcting the output of the force-torque sensor to account for effects on the output caused by elements being positioned between the force-torque sensor and the anatomical element, including the surgical tool and the end effector; and determining the kerf using the corrected output.

3. The robotic surgical system of one or more of claims 1 to 2, wherein the at least one processor is configured to monitor kerf by: measuring, based on the output of the force-torque sensor, acceleration at the surgical tool in a direction that is perpendicular to movement of the robotic arm during removal of the portion of the anatomical element; and determining the kerf based on the measured acceleration.

4. The robotic surgical system of one or more of claims 1 to 3, wherein the at least one processor is configured to perform a double integration of the measured acceleration to arrive at a displacement value which corresponds to the kerf.A00126015. The robotic surgical system of one or more of claims 1 to 4, wherein the at least one processor is configured to monitor kerf by: determining the kerf from a lookup table that matches a plurality of kerfs to a plurality of variables.

6. The robotic surgical system of one or more of claims 1 to 5, wherein the plurality of variables include one or more robotic system variables and one or more anatomical element variables.

7. The robotic surgical system of claim one or more of claims 1 to 6, wherein the one or more robotic system variables include at least one of a load on the end effector, direction of the load on the end effector, pose of the robotic arm, movement speed of the robotic arm during removal of the portion of the anatomical element, or operating parameters of the surgical tool.

8. The robotic surgical system of one or more of claims 1 to 7, wherein the one or more anatomical element variables include at least one of a depth of the removed portion of the anatomical element, a density of the anatomical element, a size of the anatomical element, a shape of the anatomical element, or a type of the anatomical element.

9. The robotic surgical system of one or more of claims 1 to 8, wherein the at least one processor is configured to select the threshold based on one or more of a type of procedure for removing the portion of the anatomical element, a type of anatomical element, or surgeon input.

10. The robotic surgical system of one or more of claims 1 to 9, wherein the one or more signals cause the tracking system to issue an audio and / or visual alert.

11. The robotic surgical system of one or more of claims 1 to 10, wherein the one or more signals cause movement of the robotic arm to stop.

12. The robotic surgical system of one or more of claims 1 to 11, wherein the one or more signals cause the surgical tool to cease operation.

13. The robotic surgical system of one or more of claims 1 to 12, wherein the one or more signals cause adjustment to an operating parameter of the surgical tool.A001260114. The robotic surgical system of one or more of claims 1 to 13, further comprising: the end effector; and the surgical tool, wherein the surgical tool is integrated with the end effector as an active end effector.

15. A device, comprising: at least one processor; and memory comprising instructions that when executed by the processor, cause the processor to: monitor kerf during removal of a portion of an anatomical element with a surgical tool based on output of a force-torque sensor in force-transmitting contact with a robotic arm and the surgical tool; determine that the monitored kerf reaches a threshold; and output one or more signals in response to determining that the monitored kerf has reached the threshold.

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