Selectively automated robotic surgery system

Abstract

A robotic surgical system and method for resection of a biological structure includes a cutting tool, a manipulator configured to move the cutting tool, and a control system. The control system associates a target plane with the biological structure, the target plane separating a portion of the biological structure to be resected from a portion of the biological structure that remains unresected. The control system controls the manipulator to align the cutting tool with the target plane. The control system controls the manipulator in an automatic mode to perform at least one of the following actions: automatically resecting along the target plane with the cutting tool, automatically retracting the cutting tool along the target plane, and automatically changing the orientation of the cutting tool on the target plane. A user or the control system can pre-select and assign whether any of the actions will be performed in manual mode or automatic mode.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to selectively automated robotic cutting systems and methods for their use. [Background technology]

[0002] Surgical saws are commonly used in total knee arthroplasty (TKA) to resect the femur and tibia and remove diseased tissue. A TKA procedure typically involves using a saw to make at least five planar cuts in the femur to accommodate a femoral implant and one planar cut in the tibia to accommodate a tibial implant. To perform the procedure, a surgeon typically must perform several manual actions with the saw. These manual actions include aligning the saw with the cutting plane, making resection cuts with the saw along that plane, retracting the saw along that plane, and reorienting the saw relative to that plane.

[0003] Cuts must be performed with extreme precision to ensure the resected bone can fit into each implant. Another factor complicating TKA surgery is the presence of four major ligaments (PCL, ACL, MCL, and LCL) surrounding the surgical site in the knee. When cutting the femur and tibia, surgeons must be careful not to accidentally cut the surrounding soft tissues and ligaments. Therefore, the surgical workflow for TKA surgery, which involves multiple cuts, is burdensome for surgeons and surgical staff, requiring a lot of time and effort. Furthermore, performing these multiple cuts manually can increase the duration of the surgery, resulting in unnecessary prolongation of the patient's anesthesia time.

[0004] There are several conventional approaches for performing TKA surgery. One approach involves using a generic or patient-specific cutting jig with a saw slot to guide the surgeon to perform each cut manually. Manufacturing and setting up such a jig significantly increases the cost and delay of the surgical procedure. Furthermore, the surgeon must manually move the saw to each plane and manually perform the cutting action, thus exposing the procedure to the challenges described above. Furthermore, manual cutting is prone to skiving, whereby the cutting tool misses or slips from the bone being cut.

[0005] Another approach is to use a robotic system to perform TKA, whereby a robotic manipulator assists the user in performing manual actions. For example, a robotic device is attached to the surgical site and robotically moves a slotted cutting guide from plane to plane. The user then manually performs each cut using a handheld power saw. However, this approach still requires the surgeon to manually perform all cutting actions.

[0006] Other robotic systems have attempted to improve surgery by utilizing a robotic arm supporting a passive planar linkage with a powered saw attached to its distal end. The robotic arm aligns the saw with the cutting plane, and the passive planar linkage mechanically constrains the saw blade's trajectory to stay on the cutting plane. The user then manually moves the saw blade toward the bone, causing the passive planar linkage to extend and allow the saw to cut relative to the plane. While this approach automates the alignment process, the user still must manually perform all other actions involved in the cutting, thereby suffering from the drawbacks mentioned above. Therefore, this approach still requires significant effort, time, manual precision to avoid accidental cuts, and surgical duration. Furthermore, such robotic systems offer little flexibility to allow the surgeon to modify how the system operates to alleviate the aforementioned concerns.

[0007] Therefore, there remains a need in the art to provide robotic systems and methods that provide solutions to at least some of the technical problems discussed above. Summary of the Invention

[0008] This Summary introduces in a simplified form a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to limit the scope of the claimed subject matter, nor is it intended to identify key features or essential features of the claimed subject matter.

[0009] In a first aspect, a robotic surgical system for resecting a anatomical structure is provided, comprising: a cutting tool; a manipulator configured to move the cutting tool; and a control system configured to: associate a target plane with the anatomical structure, the target plane separating a portion of the anatomical structure to be resected from a portion of the anatomical structure that remains unresected; control the manipulator to align the cutting tool with the target plane; and control the manipulator in an automatic mode to perform at least one of the following: automatically resect along the target plane using the cutting tool; automatically retract the cutting tool along the target plane; and automatically change the orientation of the cutting tool on the target plane.

[0010] In a second aspect, a method of operating the robotic surgical system of the first aspect is provided.

[0011] In a third aspect, a robotic surgical system for resecting an anatomical structure is provided, comprising: a cutting tool; a manipulator configured to move the cutting tool; and a control system configured to: associate a target plane with the anatomical structure, the target plane separating a portion of the anatomical structure to be resected from a portion of the anatomical structure that will remain unresected; and control the manipulator in an automatic mode to automatically align the cutting tool with the target plane, automatically resect the anatomical structure along the target plane using the cutting tool, automatically retract the cutting tool along the target plane, and automatically change the orientation of the cutting tool on the target plane.

[0012] In a fourth aspect, there is provided a method of operating the robotic surgical system of the third aspect.

[0013] In a fifth aspect, there is provided a robotic surgical system for resecting a anatomical structure, the robotic surgical system comprising: a cutting tool; a manipulator configured to move the cutting tool; and a control system configured to: associate a target plane with the anatomical structure, the target plane separating a portion of the anatomical structure to be resected from a portion of the anatomical structure that will remain unresected; control the manipulator in an automatic mode to perform at least one of the following: automatically align the cutting tool with the target plane, automatically resect the anatomical structure along the target plane using the cutting tool, and automatically retract the cutting tool along the target plane; and change the orientation of the cutting tool on the target plane in a manual mode.

[0014] In a sixth aspect, there is provided a method of operating the robotic surgical system of the fifth aspect.

[0015] In a seventh aspect, there is provided a robotic surgical system for resecting a anatomical structure, the robotic surgical system comprising: a cutting tool; a manipulator configured to move the cutting tool; a control system configured to: associate a target plane with the anatomical structure, the target plane separating a portion of the anatomical structure to be resected from a portion of the anatomical structure that will remain unresected; move the cutting tool in one or both of a manual mode and an automatic mode to align the cutting tool with the target plane; resect the anatomical structure along the target plane using the cutting tool; retract the cutting tool along the target plane; and change the orientation of the cutting tool on the target plane; and a user interface coupled to the control system, the user interface configured to allow an operator to selectively pre-assign the one or more actions to be performed in either the manual mode or the automatic mode.

[0016] In an eighth aspect, there is provided a method of operating the robotic surgical system of the seventh aspect.

[0017] In a ninth aspect, there is provided a non-transitory computer-readable medium or computer program product comprising instructions that, when executed by one or more processors, implement the user interface of the seventh aspect to enable an operator to selectively pre-assign one or more action(s) to be performed in either a manual mode or an automatic mode.

[0018] In a tenth aspect, there is provided a robotic surgery system comprising: a cutting tool, a manipulator configured to support the cutting tool, a user interface, and a control system configured to control the manipulator to move the cutting tool to perform a plurality of different actions and to receive input from the user interface to selectively pre-assign one or more of the plurality of different action(s) to be performed in either a manual or an automatic mode of operation.

[0019] In an eleventh aspect, there is provided a method of operating the robotic surgical system of the tenth aspect.

[0020] In a twelfth aspect, there is provided a robotic surgical system for resecting a biological structure, the robotic surgical system comprising: a cutting tool; a manipulator configured to move the cutting tool; and a control system configured to: associating a target plane with the biological structure, the target plane separating a portion of the biological structure to be resected from a portion of the biological structure that will remain unresected; moving the cutting tool in one or both of a manual mode and an automatic mode to align the cutting tool with the target plane; resecting the biological structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; and changing the orientation of the cutting tool on the target plane; automatically pre-assigning one or more of the actions to be performed in either a manual mode or an automatic mode; and controlling the manipulator to move the cutting tool to perform the one or more actions according to the pre-assigned mode.

[0021] In a thirteenth aspect, there is provided a method of operating the robotic surgical system of the twelfth aspect.

[0022] In a fourteenth aspect, there is provided a robotic surgical system comprising: a cutting tool; a manipulator configured to move the cutting tool; and a control system configured to acquire a plurality of actions to be performed by the manipulator moving the cutting tool, selectively pre-assign one or more of the actions to be performed in either a manual or automatic operating mode, and control the manipulator to move the cutting tool to perform one or more of the actions in accordance with the pre-assigned mode.

[0023] In a fifteenth aspect, there is provided a method of operating the robotic surgical system of the fourteenth aspect.

[0024] In a sixteenth aspect, there is provided a robotic surgical system for resecting a biological structure, the system comprising: a cutting tool; a manipulator configured to move the cutting tool; a control system configured to: associate a target plane with the biological structure, the target plane separating a portion of the biological structure to be resected from a portion of the biological structure that will remain unresected; move the cutting tool in an automatic mode to align the cutting tool with the target plane; resect the biological structure along the target plane using the cutting tool; retract the cutting tool along the target plane; and change the orientation of the cutting tool on the target plane; and a user interface coupled to the control system, the user interface configured to enable an operator to selectively pre-assign a feed rate of the cutting tool for any one or more of the actions.

[0025] In a seventeenth aspect, there is provided a method of operating the robotic surgical system of the sixteenth aspect.

[0026] In an eighteenth aspect, there is provided a robotic surgical system comprising: a surgical saw configured to cut bone; a manipulator configured to move the surgical saw; and a control system configured to: associate a target plane with the bone, the target plane distinguishing between a portion of the bone to be resected and a portion of the bone to remain unresected; control the manipulator to align the surgical saw with the target plane; control the manipulator in an automatic mode to initially penetrate a cortical surface of the bone at a first feed rate to automatically cut the bone along the target plane with the surgical saw; and, after initially penetrating the cortical surface with the surgical saw, control the manipulator to resect the bone along the target plane with the surgical saw at a second feed rate that is faster than the first feed rate.

[0027] In a nineteenth aspect, there is provided a method of operating the robotic surgical system of the eighteenth aspect.

[0028] In a twentieth aspect, there is provided a robotic surgical system comprising: a cutting tool; a manipulator configured to support the cutting tool; and a control system configured to control the manipulator in either an automatic mode or a manual mode to perform an action from among a plurality of different actions; detect occurrence of a predefined behavior of the cutting tool during performance of the action; and control the manipulator to automatically switch to a different action in response to detection of the predefined behavior.

[0029] In a twenty-first aspect, there is provided a method of operating the robotic surgical system of the twentieth aspect.

[0030] Any of the above aspects may be combined in part or in whole.

[0031] With respect to any of the above aspects, any one or more of the following embodiments are contemplated individually or in combination.

[0032] The control system may associate a target perimeter with the anatomical structure. The target perimeter may be located within a target plane. The target perimeter may correspond to a perimeter of a portion of the anatomical structure. The control system may associate a virtual boundary with the anatomical structure. The virtual boundary may be located within the target plane. The virtual boundary may be based on the target perimeter. The manipulator may be configured to resect along the target plane with the cutting tool when the cutting tool is located within the virtual boundary. The manipulator may be configured to stop resection with the cutting tool, deactivate the cutting tool, or retract the cutting tool along the target plane when the cutting tool reaches or passes the virtual boundary.

[0033] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane, and to control the manipulator in an automatic mode to automatically resect biological structures along the target plane using the cutting tool, automatically retract the cutting tool along the target plane, and automatically change the orientation of the cutting tool on the target plane.

[0034] The control system may be configured to control the manipulator in a manual mode to resect biological structures along a target plane using the cutting tool, and to control the manipulator in an automatic mode to automatically align the cutting tool with the target plane, automatically retract the cutting tool along the target plane, and automatically change the orientation of the cutting tool on the target plane.

[0035] The control system may be configured to control the manipulator in a manual mode to retract the cutting tool along the target plane, and to control the manipulator in an automatic mode to automatically align the cutting tool with the target plane, automatically resect the biological structure along the target plane using the cutting tool, and automatically change the orientation of the cutting tool on the target plane.

[0036] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane and use the cutting tool to resect the biological structure along the target plane, and to control the manipulator in an automatic mode to automatically retract the cutting tool along the target plane and automatically change the orientation of the cutting tool on the target plane.

[0037] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane and retract the cutting tool along the target plane, and to control the manipulator in an automatic mode to automatically resect biological structures along the target plane using the cutting tool and automatically change the orientation of the cutting tool on the target plane.

[0038] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane and change the orientation of the cutting tool on the target plane, and to control the manipulator in an automatic mode to automatically resect biological structures along the target plane using the cutting tool and automatically retract the cutting tool along the target plane.

[0039] The control system may be configured to control the manipulator in a manual mode to resect anatomical structures along a target plane using the cutting tool and retract the cutting tool along the target plane, and to control the manipulator in an automatic mode to automatically align the cutting tool with the target plane and automatically change the orientation of the cutting tool on the target plane.

[0040] The control system may be configured to control the manipulator in a manual mode to use the cutting tool to resect anatomical structures along a target plane and to change the orientation of the cutting tool on the target plane, and to control the manipulator in an automatic mode to automatically align the cutting tool with the target plane and automatically retract the cutting tool along the target plane.

[0041] The control system may be configured to control the manipulator in a manual mode to retract the cutting tool along the target plane and change the orientation of the cutting tool on the target plane, and to control the manipulator in an automatic mode to automatically align the cutting tool with the target plane and automatically resect the biological structure along the target plane using the cutting tool.

[0042] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane, use the cutting tool to resect the biological structure along the target plane, and retract the cutting tool along the target plane, and to control the manipulator in an automatic mode to automatically change the orientation of the cutting tool on the target plane.

[0043] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane, use the cutting tool to resect biological structure along the target plane, and change the orientation of the cutting tool on the target plane, and to control the manipulator in an automatic mode to automatically retract the cutting tool along the target plane.

[0044] The control system may be configured to control the manipulator in a manual mode to align the cutting tool with the target plane, retract the cutting tool along the target plane, and change the orientation of the cutting tool on the target plane, and to control the manipulator in an automatic mode to automatically resect biological structures along the target plane using the cutting tool.

[0045] The control system may be configured to control the manipulator in an automatic mode by automatically moving the cutting tool along a predetermined tool path. The force / torque sensor may be configured to sense a force / torque applied to the cutting tool by an operator, and the control system is configured to command movement of the cutting tool in response to the sensed force / torque, thereby controlling the manipulator in a manual mode.

[0046] The control system may be configured to control the manipulator in an automatic mode to initially advance the cortical surface of the bone at a first feed rate until the surgical saw reaches a predetermined depth to automatically cut the bone along a target plane with the surgical saw. After reaching the predetermined depth, the control system may be configured to control the manipulator to resect the bone along the target plane with the surgical saw at a second feed rate. The sensing system may be configured to detect bone characteristics, and the control system is configured to: control the manipulator in the automatic mode to initially advance the cortical surface of the bone at a first feed rate to automatically cut the bone along the target plane with the surgical saw; determine from the sensing system that the surgical saw has broken through the cortical surface of the bone; and, in response to detecting breakthrough of the cortical bone, control the manipulator to resect the bone along the target plane with the surgical saw at the second feed rate.

[0047] A user interface may be coupled to the control system and configured to allow an operator to selectively assign manual or automatic mode control. The selective mode assignment may be to perform at least one of the following actions: aligning a cutting tool with a target plane; resecting an anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; and changing the orientation of the cutting tool on the target plane. The selective action / mode assignment may be applied to all planar resections of a surgical procedure. The selective action / mode assignment may be selected for each individual planar resection of a surgical procedure. The selective action / mode assignment may be determined preoperatively or intraoperatively. The selective action / mode assignment is based on a surgical plan. The selective action / mode assignment may be performed for actions specifically related to total hip replacement surgery, partial knee replacement surgery, shoulder replacement surgery, spinal surgery, or trauma surgery. Any action may include sub-steps or sub-actions. The selective action / mode assignment may be performed for any sub-steps or sub-actions of the described actions. A user can select a feedrate for any of the described actions, or for any or each sub-step of the described actions. The control system is configured to automatically and selectively pre-assign manual mode control or automatic mode control to perform any of the described actions. The user interface may be provided on an extended reality, augmented reality, or mixed reality display device worn by the user.

[0048] The action may include one of the following: aligning the cutting tool with the target plane, using the cutting tool to cut along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane. A different action may include a different one of the following: aligning the cutting tool with the target plane, using the cutting tool to cut along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane. The control system may control the manipulator in a manual mode to perform the action, detect occurrence of a predefined behavior during performance of the action in the manual mode, and control the manipulator to automatically switch to a different action and automatically switch from the manual mode to the automatic mode in response to detecting the predefined behavior. The predefined behavior may include at least one of the following: a collision of the cutting tool with a virtual boundary, a change in direction of the cutting tool, and the cutting tool removing a predefined amount of material from the target plane.

[0049] The manipulator may include an arm formed from multiple links and joints. The manipulator may be held by hand (against gravity) and may include a gripping portion and a moving portion including joints and actuators for moving the moving portion relative to the gripping portion. The resection may be for a total knee surgery. The resection may include one or more incisions in a total knee surgery, including incisions in the femur and / or tibia. The resection may be for a revision surgery, or the resection may be for a shoulder surgery, such as, but not limited to, stemless shoulder surgery or reverse or anatomical (anatomical) shoulder arthroplasty. The cutting tool may be a planar cutting tool. The cutting tool may be a surgical saw. The cutting tool may be a side cutting burr or a router.

[0050] Any of the above embodiments are contemplated individually or in combination.

[0051] The advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0052] [Figure 1] FIG. 1 illustrates a perspective view of a robotic cutting system in an operating room, according to one embodiment. [Figure 2] FIG. 1 is a perspective view of an example of a manipulator of a robotic cutting system that supports a cutting tool. [Figure 3] 1 is a side view of a surgical site including a patient's femur and tibia, where a robotic cutting system aligns cutting tools with various target planes associated with the target site, according to an example. [Figure 4] 1 illustrates a cutting tool shown relative to a femur with a target plane, target perimeter, and virtual boundary associated with the femur, according to an example. [Figure 5] 1 is a table detailing operations that a robotic cutting system can perform on a cutting tool using manual mode, automatic mode, and / or a combination thereof, according to an example. [Figure 6] 1 illustrates a cutting tool shown on a femur, where the cutting tool is controlled to perform cuts along a predefined path, according to one embodiment. [Figure 7] 1 illustrates a cutting tool shown relative to a femur, according to one embodiment, where the cutting tool is controlled to perform multiple cuts along multiple predefined paths by positionally moving relative to a target plane. [Figure 8] 1 illustrates a cutting tool shown relative to a femur, where the cutting tool is controlled to retract along a target plane, according to one embodiment. [Figure 9]1 illustrates a cutting tool relative to a femur, according to an example, where the cutting tool is controlled to change orientation relative to a target plane after making a first cut in preparation for making a second cut. [Figure 10] 1 illustrates a cutting tool shown relative to a femur, according to an example, where the cutting tool is controlled to change orientation relative to the target surface so that the tool path is curved when performing a first cut. [Figure 11] 1 is a graphical representation of a display screen with which an operator interacts to select an action / mode combination for a surgical procedure or surgical step, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0053] I. System Overview

[0054] Referring to the figures, a robotic cutting system 10 for use during a surgical procedure is shown. Typically, the surgical procedure involves cutting a surgical site 12, such as hard tissue (bone), soft tissue, etc. In some embodiments, the surgical procedure includes total knee surgery. In other embodiments, the surgical procedure includes partial knee surgery, partial or total hip replacement, shoulder replacement such as stemless or reverse shoulder arthroplasty, trauma surgery, spinal surgery, or any type of revision surgery from the aforementioned surgeries. The surgical procedure may also be any other type of surgery requiring the use of a cutting instrument.

[0055] The robotic cutting system 10 is designed to cut material. In some cases, the material (e.g., bone) will be replaced with a surgical implant, such as a hip, knee, shoulder, or spinal implant (including unicondylar, bicondylar, or total knee implants, acetabular cups, femoral stems, humeral implants, etc.). Some of these types of implants are disclosed in U.S. Patent Application Publication No. 2012 / 0330429, entitled "Prosthetic Implant and Method of Implantation," the entire disclosure of which is expressly incorporated herein by reference. It should be understood that the systems and methods disclosed herein can be used to perform other procedures, surgical or non-surgical, or for industrial or other applications.

[0056] The robotic cutting system 10 may include a navigation system 13 including a localizer 14 and a tracking device 16, one or more displays 18, and a robotic manipulator 20 including a robotic arm. The manipulator 20 has a base 22, and the robotic arm may include a base link 24 rotatably coupled to the base 22 and multiple arm links 26 extending continuously from the base link 24 to a distal end 28. The arm links 26 pivot / rotate about multiple joints within the robotic arm. The manipulator 20 may have a serial arm configuration as shown, a parallel link configuration, or the system may employ multiple robotic arms.

[0057] The cutting tool 30, or end effector, is coupled or attached to the distal end 28 of the manipulator 20. The manipulator 20 can move the cutting tool 30 with multiple degrees of freedom, for example, five or six degrees of freedom. In some cases, one or more of the links 26 may be passively moved by a user's physical force. Such links operate as planar mechanisms, where the movement of the joint(s) is mechanically constrained to be along a plane.

[0058] In several examples described herein, the cutting tool 30 is a saw blade 50, and therefore these terms may be used interchangeably throughout the description. The saw blade 50 is actuated or powered such that the saw blade 50 oscillates and cuts tissue. The saw blade 50 may be of any size, shape, or type (e.g., straight blade, crescent blade, etc.). In some embodiments, the saw blade 50 is formed from a single piece of material, such as metal, by stamping and / or machining. The saw blade 50 may be configured to create a cut with a substantially flat surface or to provide a cut with a rounded contour. The cutting tool 30 and associated saw blade 50 are similar to those described in U.S. Patent Application Publication No. 2017 / 0348007, entitled "Surgical Saw and Saw Blade for use therewith," filed June 2, 2017, which is incorporated herein by reference. The cutting tool 30 and associated saw blade 50 may be similar to those described in U.S. Patent Application Publication No. 2014 / 0180290, entitled "Systems and Methods for Haptic Control of a Surgical Tool," filed December 21, 2012, which is incorporated herein by reference.

[0059] In some embodiments, such as the embodiment shown in FIG. 2 , the cutting tool 30 includes a coupler 40 having a housing 42 for mounting to the robotic manipulator 20. It is also contemplated that a separate motor 44 may be disposed within the housing 42 of the coupler 40. The motor 44 may be of any suitable type for operating the cutting tool 30, including, but not limited to, a pneumatic or electric motor. The motor 44 may be configured to impart oscillating motion to a saw blade 50 of the cutting tool 30 during a surgical procedure, for example. The motor 44 may provide cyclic linear and / or cyclic angular motion, such as that used in an oscillating sagittal saw. In some embodiments, the cutting tool 30 may include a drive hub 46 coupled to the motor 44. The saw blade 50 may include a mounting portion 52 configured to be removably coupled to the housing 42. The saw blade 50 includes a cutting portion 54 opposite the mounting portion 52, the cutting portion 54 having a plurality of teeth 56.

[0060] Although a saw blade 50 is described as one example of a cutting tool 30, other cutting tools may be utilized to perform any of the techniques described herein, such as a cutting bar (such as a side cutting bar), a router, a pressurized water cutting system, a laser cutting system, a steerable wire path and wire saw guide, and the like.

[0061] A robotic controller 32, which forms part or all of the control system 32, 36, is coupled to the robotic manipulator 20 and controls the manipulator 20 or provides guidance to the surgeon during operation of the cutting tool 30. In one embodiment, the robotic controller 32 is configured to control the manipulator 20 (e.g., its joint motors) to provide haptic feedback to the operator via the manipulator 20. This haptic feedback helps the surgeon constrain or inhibit manual manipulation (e.g., movement) of the cutting tool 30 beyond a predefined virtual boundary associated with the surgical procedure. Such a haptic feedback system and associated haptic objects defining the virtual boundary are described, for example, in U.S. Pat. No. 8,010,180, which is incorporated herein by reference in its entirety. In one embodiment, the robotic cutting system 10 comprises a RIO™ Robotic Arm Interactive Orthopedic System manufactured by MAKO Surgical Corp.

[0062] In some embodiments, the manipulator 20 operates autonomously based on a predefined toolpath and / or other predefined movements to perform a surgical procedure. Such movements may be defined during and / or prior to the surgical procedure. Further embodiments utilize a combination of manual and autonomous control. For example, U.S. Patent No. 9,566,122, the entire contents of which are incorporated herein by reference, describes a robotic system that employs both a manual mode in which an operator applies forces to the cutting tool 30 to move the manipulator 20, and a semi-automatic mode in which an operator holds a pendant and controls the manipulator 20 to autonomously follow a toolpath. Additional features and implementations of the manual and automatic modes are described in more detail below.

[0063] The manipulator 20 may, in some cases, be a handheld robotic manipulator. The handheld robotic manipulator may support a cutting tool 30, such as a saw blade 50 or a cutting burr, for making surgical incisions. The handheld manipulator includes a gripper that is held by a user's hand to support the manipulator against gravity. Coupled to the gripper is a moving part that includes an actuator system for moving the cutting tool 30 with multiple degrees of freedom. Control systems 32, 36 can command the movement of the actuators to autonomously align and maintain the cutting tool 30 with a target plane. In some cases, the actuators may be configured to linearly retract the cutting tool 30 or change the orientation of the cutting tool 30. In other cases, the handheld manipulator may hold the cutting tool 30 stationary, effectively allowing the manipulator to be operated manually. An example of a handheld robotic manipulator supporting a cutting tool is described in International Patent Application No. PCT / US2021 / 049440, filed September 8, 2021, entitled "Systems and methods for guiding movement of a handheld medical robotic instrument," the contents of which are incorporated by reference in their entirety into this specification.

[0064] The navigation system 13 is configured to track the movement of various objects within the operating room, including, for example, the cutting tool 30, the patient's target anatomy, such as the femur F and tibia T, and / or other objects. The navigation system 13 tracks these objects for the purposes of displaying their relative positions and orientations to the surgeon and, in some cases, for the purposes of controlling or constraining manual manipulation of the cutting tool 30 relative to a virtual boundary associated with the patient's anatomy.

[0065] The navigation system 13 includes a cart assembly 34 that houses a navigation controller 36. In one embodiment, the navigation controller 36 and the robot controller 32 collectively form the control system 32, 36 of the robotic cutting system 10. A navigation interface is in operative communication with the navigation controller 36. The navigation interface includes a display 18 adjustably mounted to the cart assembly 34. Input devices such as a keyboard and mouse can be used to input information into the navigation controller 36 or to otherwise select / control certain aspects of the navigation controller 36. Other input devices, including a touchscreen (not shown) or voice activation, are contemplated. In some cases, one or more of the displays 18 may be implemented using an extended, augmented, or mixed reality head-mounted display device worn by the user. The head-mounted device can display any aspect of the technology described herein using virtual images superimposed on a view of the real world or an image of the surgical site.

[0066] The localizer 14 communicates with the navigation controller 36. In the illustrated embodiment, the localizer 14 is an optical localizer and includes a camera unit (an example of a sensing device). The camera unit includes an outer housing that houses one or more optical position sensors. In some embodiments, at least two optical sensors, and sometimes three or more optical sensors, are used. The optical sensors may be separate charge-coupled devices (CCDs). The camera unit is mounted on an adjustable arm to position the optical sensors relative to the ideally unobstructed field of view of the tracking device 16, described below. In some embodiments, the camera unit is adjustable in at least one degree of freedom by rotating about a rotational joint. In other embodiments, the camera unit is adjustable in approximately two or more degrees of freedom.

[0067] The localizer 14 includes a localizer controller (part of the navigation controller) that communicates with the light sensors to receive signals from the light sensors. The localizer controller communicates with the navigation controller 36 via either a wired or wireless connection (not shown). One such connection can be an IEEE 1394 interface, which is a serial bus interface standard for high-speed communication and isochronous real-time data transfer. The connection can also use a proprietary protocol. In other embodiments, the light sensors communicate directly with the navigation controller 36.

[0068] The position and orientation signals and / or data are transmitted to a navigation controller 36 for purposes of tracking the object. The cart assembly 34, display 18, and localizer 14 can be similar to those described in U.S. Patent No. 7,725,162 to Malackowski et al., issued May 25, 2010, and entitled "Surgery System," which is incorporated herein by reference.

[0069] The navigation controller 36 can be a personal computer, a laptop computer, or any other suitable type of controller. The navigation controller 36 includes a display 18, a central processing unit (CPU) and / or other processor, memory (not shown), and storage (not shown). The navigation processor can be any type of processor, microprocessor, or multiprocessor system. The navigation controller 36 is loaded with software, described below. The software converts signals received from the localizer 14 into data representing the position and orientation of the object being tracked.

[0070] The navigation system 13 includes multiple tracking devices 16, also referred to herein as trackers. In the illustrated embodiment, the trackers 16 are coupled to separate bones of the patient, e.g., the femur F and the tibia T. In some cases, the trackers 16 are rigidly fixed to portions of the bone via bone screws, bone pins, etc. In other cases, bone clamps may be used to attach the trackers 16. In further embodiments, the trackers 16 may be attached to portions of other tissue types or anatomical forms. The position of the trackers 16 relative to the anatomy to which they are attached can be determined by registration techniques, such as point-based registration, which uses a digitizing probe P (e.g., a navigation pointer) to turn contact off on a bone marker on the bone, or point-based registration, which turns contact on at multiple points on the bone for surface-based registration. Conventional registration techniques can be used to correlate the pose of the trackers 16 to the patient's anatomy, e.g., the bone being treated.

[0071] The base tracker 16 is also coupled to the base 22 and tracks the pose of the cutting tool 30, e.g., when combined with data obtained from joint encoders in the joints of the manipulator 20 that partially define the spatial transformation from the base 22 to the distal end 28 of the manipulator 20, and when combined with data describing the position of the cutting tool 30 relative to the distal end 28. In other embodiments, a separate tracker 16 can be affixed to the cutting tool 30, e.g., integrated into the cutting tool 30 during manufacturing, or separately attached to the cutting tool 30 in preparation for a surgical procedure. In either case, the working end of the cutting tool 30 is tracked by the base tracker 16 or another tracker. The working end may be the distal end of an accessory to the cutting tool 30. Such an accessory may include a saw blade 50.

[0072] In the illustrated embodiment, the trackers 16 are active trackers. In this embodiment, each tracker 16 has at least three active tracking elements or markers M, such as LEDs, for emitting light to the localizer 14 and optical sensors. In other embodiments, the trackers 16 may be passive trackers that reflect infrared light to the optical sensors. The navigation controller 36 generates data indicating the relative position and orientation of the tracker 16 with respect to the localizer 14 based on the received optical signals. In some cases, more or fewer markers may be used. For example, if the tracked object is rotatable about a line, two markers may be used to determine the orientation of the line by measuring the positions of the markers at various positions around the line. While the localizers 14 and trackers 16 are described above as utilizing optical tracking technology, it should be understood that other tracking modalities, such as electromagnetic tracking, radio frequency tracking, ultrasonic tracking, inertial tracking, machine vision tracking, or combinations thereof, may alternatively or additionally be used to track the object.

[0073] II. Overview of surgery

[0074] In one example, the robotic cutting system 10 may be used to perform knee arthroplasty, and more specifically, total knee surgery. Referring to FIG. 3 , the robotic cutting system 10 may be used to resect the femur F and / or the tibia T. For example, the robotic cutting system 10 may be configured to remove damaged cartilage and / or bone from the femur F by performing one or more of an anterior femoral cut AFC, a femoral chamfer cut CC1, CC2, a distal femoral cut DFC, and a posterior femoral cut PFC using the cutting tool 30. Additionally, the robotic cutting system 10 may be configured to remove damaged cartilage and / or bone from the tibia T by performing a tibial plateau cut. Depending on the requirements of the surgical plan and the intended implant, the surgeon may perform any number of cuts.

[0075] The robotic cutting system 10 can resect the femur F and / or tibia T by cutting along one or more target planes 58. The target planes 58 are planes along which planar cuts are made by the cutting tool 30. The target planes 58 separate the portions of the anatomy that are to be resected from the portions of the anatomy that are not to be resected. For example, with reference to FIG. 4 , a portion R of the femur F within the target plane 58 defines the portion of the femur F that is to be resected by the cutting tool 30. Thus, portions of the femur F that lie outside of portion R and the target plane 58 are not resected by the cutting tool 30, and portions of the femur F that lie inside of portion R and the target plane 58 are resected by the cutting tool 30.

[0076] The target plane 58 may be a virtual object associated with or aligned to the patient's anatomy. The navigation system 13 can be used to perform this association using any type of registration technique, such as touching a pointer (P) to the surface of the bone, or other image-based or image-less registration process. The target plane 58 can be defined relative to a 3D model of the bone during the surgical planning process. The 3D model of the bone can be aligned to the actual bone to virtually position the target plane 58 in the coordinate system of the surgical site. The target plane 58 can be defined intraoperatively or preoperatively and can be updated at any time by the surgeon using the user interface.

[0077] The target plane 58 may be defined such that resection along the target plane(s) 58 performs an anterior femoral cut AFC, a femoral chamfer cut CC1, CC2, a distal femoral cut DFC, a posterior femoral cut PFC, or a tibial plateau cut TC. For example, in FIG. 4 , the target plane 58 is positioned such that the cutting tool 30 performs a distal femoral cut DFC when the cutting tool 30 resects along the target plane 58.

[0078] The control systems 32, 36 may determine a protective virtual boundary VB that defines the limits of the anatomy beyond which the cutting tool 30 must not resect. In some cases, the virtual boundary VB may be based on soft tissue locations identified using preoperative or intraoperative images / models (e.g., CT scans, X-ray images, MRI images, 3D models, etc.) of the patient's anatomy. The control systems 32, 36 may be configured to associate the virtual boundary VB with the patient's anatomy using registration techniques such as those described above. The virtual boundary VB may be located completely or partially within the target plane 58. A separate virtual boundary VB may be associated with each target plane 58. The navigation controller 36 determines the relative position of the cutting tool 30 with respect to the virtual boundary VB. The manipulator 20 may be controlled to allow the cutting tool 30 to resect along the target plane 58 when the cutting tool 30 is located within or adheres to the virtual boundary VB. In other words, the cutting tool 30 may be actuated to remove tissue when within the virtual boundary VB. When the cutting tool 30 reaches or crosses the virtual boundary VB, the manipulator 20 is configured to stop the cutting tool 30 from resecting along the target plane 58. Collision with the virtual boundary VB may cause a reaction force that haptically pushes the cutting tool 30 away from the virtual boundary VB. Additionally or alternatively, the manipulator 20 may immediately deactivate the cutting tool 30 and / or automatically retract the cutting tool 30 in response to the collision with the virtual boundary VB. Methods for controlling the robotic cutting system 10 based on virtual / haptic objects such as the virtual boundary VB are similar to those described in U.S. Pat. Nos. 8,010,180, 9,119,655, and U.S. Patent Application Publication No. 2014 / 0180290, the contents of both of which are incorporated herein by reference in their entireties.

[0079] The geometry of the virtual boundary VB may be defined based on or uniquely for the type of cut being performed by the cutting tool 30 (e.g., anterior femoral cut AFC, femoral chamfer cuts CC1, CC2, distal femoral cut DFC, posterior femoral cut PFC, and / or tibial plateau cut TC). For example, the virtual boundary VB can be defined to define the extent of material to be removed for each particular cut. The virtual boundary VB can be implant-specific and / or patient-specific. The thickness of the virtual boundary VB can be defined based on the thickness of the target plane 58 or can be thicker than the target plane 58 as an added measure of redundancy. The width and depth of the virtual boundary VB can be defined based on the physical width and depth of each portion of the anatomy where the cut is being performed.

[0080] In some cases, the virtual boundary VB may be based on a target boundary 60 associated with the patient's anatomy, as shown in FIG. 4 . Specifically, the target boundary 60 is located within the target plane 58 and corresponds to the planar edge or profile of the bone that will exist after a cut is performed along the target plane 58. The virtual boundary VB may be coplanar with the target plane 58 and offset a predefined distance beyond the target boundary 60. In this manner, the cutting tool 30 may remain activated after breaking through the target boundary 60 but cease activation upon reaching or crossing the virtual boundary VB. In some cases, the predefined distance from the target boundary 60 may be 2 mm, 5 mm, 10 mm, or 15 mm from the target boundary 60. The offset of the virtual boundary VB from the target boundary 60 may be defined based on the proximity of the soft tissue to the target boundary 60, which may be determined from patient image data, modeling, or pointer (P) registration of soft tissue features. The virtual boundary VB may be offset a different distance from the target boundary 60 depending on the shape of the cut and the proximity of the soft tissue. The virtual boundary VB may also have a shape or contour based on the shape of the target boundary 60 .

[0081] The target plane 58, target perimeter 60, and virtual boundary VB may all be defined by points, lines, planes, volumes, etc., and may be one-dimensional, two-dimensional, or three-dimensional. For example, the target plane 58, target perimeter 60, and virtual boundary VB may be defined as models, and may be solid models (e.g., constructed from structural solid geometry, etc.), surface models (e.g., surface meshes, etc.), or any suitable form of three-dimensional model. The target plane 58, target perimeter 60, and virtual boundary VB may all be registered pre-operatively or intra-operatively, and may be based on patient images / models (e.g., CT scans, X-ray images, MRI images, three-dimensional models, etc.) of the patient's anatomy mapped to the patient's actual anatomy using a navigation system.

[0082] III. Manual and Automatic Modes

[0083] The robotic cutting system 10 can be configured to operate in a manual mode and an automatic mode.

[0084] In manual mode, the operator manually directs and the robot controller 32 controls the movement of the robotic manipulator 20, and therefore the movement of the cutting tool 30 at the surgical site. The operator physically contacts the cutting tool 30 and / or manipulator 20 to move the cutting tool 30.

[0085] The robotic manipulator 20 may include a force / torque sensor S configured to measure forces and torques applied by an operator to the cutting tool 30 and / or manipulator 20. In one embodiment, as shown in FIG. 1 , the force / torque sensor S is positioned between the cutting tool 30 and the distal end 28 of the manipulator 20. The force / torque sensor S can be configured to monitor the forces and torques applied by the operator to the cutting tool 30 in many degrees of freedom during manual mode. In one embodiment, the force / torque sensor S monitors the load applied to the cutting tool 30 in six degrees of freedom (6 DOF). Those skilled in the art will appreciate that the force / torque sensor S can monitor the load applied to the cutting tool 30 and / or manipulator 20 in any suitable number of DOFs, up to a maximum of six DOFs. In some cases, the operator may need to press and hold a trigger or switch to activate a movement command in manual mode. In other examples, the operator can activate any movement command in manual mode simply by applying force and torque to the tool 30.

[0086] In response to the applied forces and torques, the force / torque sensors S may be configured to generate corresponding inputs that may be used by the control systems 32, 36. In response to the operator-applied forces and torques, the robotic manipulator 20 moves the cutting tool 30 in a manner that emulates the movement that would have occurred based on the operator-applied forces and torques. The robot controller 32 processes the signals to determine control signals for determining a target position of the cutting tool 30 and / or a posture of the robotic manipulator 20. Based on the determination of the arm target position, the robot controller 32 selectively activates the motors of the robotic manipulator 20 to advance the manipulator 20 to the target position.

[0087] In automatic mode, the robot controller 32 directs the automatic movement of the robotic manipulator 20, which in turn directs the automatic movement of the cutting tool 30 at the surgical site. In automatic mode, the robot controller 32 can automatically move the cutting tool 30 without operator assistance. Without operator assistance may mean that the operator does not physically contact the cutting tool 30 to apply force to move the cutting tool 30. Instead, the operator may use some form of control to remotely manage starting and stopping of movement. For example, the operator may press and hold a button on the remote control to start movement of the cutting tool 30 and release the button to stop movement of the cutting tool 30. Alternatively, the operator may press a button to start movement of the cutting tool 30 and a button to stop movement of the cutting tool 30. In automatic mode, the robot controller 32 directs the automatic movement of the cutting tool 30 along a predefined tool path and / or based on predefined movements or actions to perform the surgical procedure. The tool path, movements, or actions performed in automatic mode can be defined before and / or during the surgical procedure.

[0088] The manual and automatic modes utilized in the techniques described herein are similar to those described in U.S. Patent No. 9,119,655, entitled "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes," the entire contents of which are incorporated herein by reference. Examples of how the manual and automatic modes may be implemented with respect to control of the cutting tool 30 are described in detail below.

[0089] IV. Manual / Automatic Surgery Action of Cutting Tools

[0090] During a surgical procedure involving the resection of anatomical structures, the control systems 32, 36 can command various actions on the cutting tool 30. For example, the robotic cutting system 10 can (1) align the cutting tool 30 with one or more target planes 58, (2) resect a patient's anatomical structure along any of the target planes 58, (3) retract the cutting tool 30 along any of the target planes 58, and (4) change the attitude (position and / or orientation) of the cutting tool 30 relative to the target planes 58. These primary techniques involved in resection are referred to as "actions." These actions can be combined in one or more steps of a procedure. For example, the tool 30 can be controlled to resect or retract along the target plane 58 by changing its attitude along the target plane 58. Furthermore, as will be understood below, any action described herein can include or be defined to include multiple sub-actions or sub-steps. For example, a resection action can include an entry cut and a plunge cut along the same plane 58. Other actions of the cutting tool 30 beyond those specifically described herein are also contemplated.

[0091] Figure 3 shows an example of the operation of the robotic cutting system 10 to align the cutting tool 30 with the target plane 58. Figures 6 and 7 show an example of the robotic cutting system 10 using the cutting tool 30 to resect a patient's anatomy along the target plane 58. Figure 8 shows an example of the robotic cutting system 10 retracting the cutting tool 30 along the target plane 58. Figures 9 and 10 show an example of the robotic cutting system 10 changing the orientation of the cutting tool 30 relative to the target plane 58.

[0092] Individual actions of the cutting tool 30 can occur in manual mode or automatic mode. For example, referring to FIG. 5 , a table is shown illustrating various combinations of manual and automatic modes for each action. In "Action / Mode Combination" Example 3 in the table, for example, in manual mode, alignment of the cutting tool 30 with the target plane 58 can be performed manually, in automatic mode, resection along the target plane 58 can be performed automatically, in automatic mode, retraction of the cutting tool 30 along the target plane 58 can be performed automatically, and in automatic mode, a change in the orientation of the cutting tool 30 on the target plane 58 can be performed automatically. All of the example actions and combinations of modes shown in the table in FIG. 5 are contemplated and can be implemented by a surgical system to perform automatic or combined automatic / manual resection of biological structures with the cutting tool 30.

[0093] Additionally, the control systems 32, 36 may allow pre-operative or intra-operative selection or determination (prior to performing such actions) of which actions should be performed in manual mode and which actions should be performed in automatic mode. The selection of action / mode combinations can be made for any substep of an action. The selection can be made by the operator or determined by the control systems 32, 36. For example, the control systems 32, 36 may automatically determine the selection of action / mode combinations based on the current surgical plan, past surgical plan data, statistical patient data, and / or past robotic data. In some cases, machine learning algorithms or trained neural networks may be utilized to adaptively learn which action / mode combinations to select. For example, the control systems 32, 36 may infer from these various data sources that the surgeon prefers that alignment to the target plane and reorientation of the tool relative to the target plane be performed automatically, while resection and retraction actions be performed manually. The control systems 32, 36 may then output a surgical or resection plan that includes a selection or suggestion of predefined actions / modes. The selection or suggestion of predefined actions / modes by the control systems 32, 36 can be overridden by the operator pre-operatively or intra-operatively, if desired.

[0094] In some cases, the data in the table of FIG. 5 can be refined and displayed in a GUI, accessible on the display 18, as shown in FIG. 11, to allow the operator to select predefined action / mode combinations. As mentioned above, the display 18 may be a head-mounted augmented reality device or other type of user-accessible monitor. Using a head-mounted device, any of the selections described herein can be made using gesture control detection, gaze detection, voice commands, etc. The operator can select action / mode combinations for one or more cuts, or the action / mode combination can be the same for all cuts. FIG. 11 shows six cuts in the femur and tibia. The operator selects one cut, such as the AFC anterior femoral cut. For this particular cut, the operator then selects the mode in which each action should be performed, e.g., (M—manual mode, A—automatic mode). As shown in the example, the operator selected to perform all actions for the AFC cut in automatic mode, except for tool pose changes (which are performed in manual mode). Other selections include mode selection for substeps of specific actions. For example, a cutting action may include a substep that performs a series of cuts to reduce tool skiving. The operator can select a mode for each individual substep of the action. Additionally, the default feed rate for the tool may be displayed to the operator on the GUI for any action. The operator can use the GUI to confirm the use of the default feed rate or change the feed rate as needed.

[0095] This embodiment provides the operator with the flexibility to selectively and precisely control the extent to which a procedure is automated or performed manually. Each surgeon may have individual preferences regarding whether to use manual or automated modes for various steps or actions in a procedure. Therefore, by providing this versatile form of control to a robotic system, the system is well-suited to address each surgeon's unique needs. As a result, the surgical workflow for multiple cuts in a TKA procedure can be streamlined and less demanding for the surgeon and surgical staff. Furthermore, the ability to selectively automate certain actions as needed can shorten the duration of the surgical procedure and the time the patient is under anesthesia. Therefore, robotic systems offer the advantage of providing superior surgical outcomes compared to conventional systems and techniques.

[0096] Once the selection is complete and surgery begins, the manipulator 20 can be controlled to initiate the selected mode of each action upon completion of each action. Completion of each action can be determined automatically or manually. For example, kinematic and / or localization data can be used to identify or infer robotic motion, such as a change in alignment to another target plane 58. The relationship between the tool 30 and the anatomy can be recorded in memory and compared to determine whether a particular action, such as a retraction or resection cut, has been completed. Alternatively, the operator can use the display screen 18 or other user input to notify the control system 32, 36 that a particular action has been performed. The display screen 18 or other user interface may require operator confirmation before initiating the next step or cut.

[0097] Selective action / mode assignment can be performed intraoperatively (as described above) or preoperatively. If performed preoperatively, action / mode assignment can be determined based on surgeon preference or surgical plan. In some cases, historical or statistical procedural data may be analyzed to determine action / mode assignment. For example, the data may be based on robotic data from previous procedures. The data may comprehensively indicate the duration of each action, the accuracy parameters for each action, the severity of each action, error events for each action, etc. From this data, a surgical plan can be created and each action can be assigned a manual or automatic mode.

[0098] The operator can also use the GUI to override manual mode actions with automatic mode actions, or vice versa. Additionally or alternatively, when the tool 30 is operated in automatic mode for a particular action, the operator can exert force / torque and / or depress the trigger of the cutting tool 30 to override automatic control with manual mode control. Similarly, when the tool 30 is operated in manual mode for a particular action, the operator can temporarily stop and utilize the user interface or GUI to override manual control with automatic mode control.

[0099] An operator can remotely manage the starting and stopping of actions in automatic mode using some form of control. For example, the control can be configured to automatically control actions individually. In one such example, the control may include physical buttons on the cutting tool 30 or handheld control pendant, or digital buttons displayed on a GUI, for individually initiating each action in automatic mode. In this manner, an operator of the robotic cutting system 10 may perform one or more actions in manual mode and then easily transition to performing one or more actions in automatic mode. The manual and automatic modes for each action are described in more detail below.

[0100] Thus, the technology described herein enables selective automatic and manual mode control for performing resection surgeries. The operator is empowered to define which actions are manually controlled, providing an enhanced sense of control over certain actions. Conversely, the operator can designate automatic mode control for other actions that may, for example, be more complex or add time to the surgical workflow. The benefits are further enhanced by allowing the surgeon to make such choices for each cut in the surgery. For example, the surgeon may choose to fully automate all actions for the tibial cut, but select to automate only certain actions for the femoral cut. Thus, the robotic system 10 performs more dynamic techniques than traditional manually controlled systems while providing the operator with selective control over the degree to which the surgery is automated.

[0101] A. Action: Align cutting tool with target plane

[0102] 3 illustrates an example of the robotic manipulator 20 (in manual or automatic mode) aligning the cutting tool 30 with the target plane 58. As shown, the cutting tool 30 is aligned with a first target plane 58′, and the cutting tool 30 moves along the first target plane 58′ to perform a chamfer cut CC1.

[0103] Additionally, the cutting tool 30 may be aligned with multiple target planes 58 during a surgical procedure. For example, with reference to FIG. 3 , the cutting tool 30 may first be aligned with a first target plane 58′, such that a chamfer cut CC1 is performed by moving the cutting tool 30 along the first target plane 58′. The cutting tool 30 may then be aligned with a second target plane 58″, such that a distal femur cut DFC is performed by moving the cutting tool 30 along the second target plane 58″.

[0104] In other examples, the cutting tool 30 may be aligned with any suitable number of target planes 58 in any suitable order during a surgical procedure. For example, the cutting tool 30 may be aligned with the target plane 58 to perform an anterior femoral cut AFC, then aligned with the target plane 58 to perform a chamfer cut CC1, then aligned with the target plane 58 to perform a distal femoral cut DFC, then aligned with the target plane 58 to perform a chamfer cut CC2, then aligned with the target plane 58 to perform a posterior femoral cut PFC, and finally aligned with the target plane 58 to perform a tibial cut.

[0105] In the manual mode, the cutting tool 30 may be aligned with the target plane 58. In such a case, the operator may apply force / torque to the cutting tool 30 to move the cutting tool 30 and align the cutting tool 30 with the target plane 58. Additionally, in the manual mode, the control systems 32, 36 may operate to guide the alignment of the cutting tool 30. For example, the robot controller 32 may permit movement of the cutting tool 30 if the forces and torques applied by the operator to the cutting tool 30 move the cutting tool 30 toward the target plane 58. Similarly, the control systems 32, 36 may prevent movement of the cutting tool 30 if the forces and torques applied by the operator to the cutting tool 30 move the cutting tool 30 away from the target plane 58.

[0106] In manual mode, pulling haptics can be utilized to guide the operator to move toward the target plane 58. In some cases, the control systems 32, 36 can detect the direction of a force / torque manually applied by the operator to the tool 30 in manual mode and determine whether the force / torque direction is toward or intersects with the target plane 58. If so, the manipulator 20 can be controlled to move the tool 30 toward the target plane 58. In some cases, this movement is implemented using pulling haptics. Such attraction can be implemented by a guide handler of the control systems 32, 36 obtaining a current state of the tool 30 (away from the target plane) and a target state of the tool 30 (aligned with the target plane), and generating one or more virtual constraints based on the current state and the target state. The control systems 32, 36 can implement constraint forces adapted to pull the tool 30 from the virtual constraints based on the current state toward the target state aligned with the target plane. The control systems 32, 36 may implement a virtual simulator that simulates the dynamics of the tool 30 in a virtual simulation based on inputs from the force / torque sensors S and constraint forces and outputs a commanded pose. The control systems 32, 36 then command the manipulator 20 to move the tool 30 to align with the target plane 58 based on the commanded pose, thereby providing haptic feedback to the operator to guide the operator in placing the tool 30 in the target state. Examples of pulling haptics that can be utilized to guide the tool to the target plane may include those described in U.S. Patent Application No. 17 / 701,989, entitled "Systems And Methods For Guiding Movement Of A Tool," the entire contents of which are incorporated herein by reference.

[0107] In an automatic mode, the cutting tool 30 can be aligned with the target planes 58. In such a case, the control system 32, 36 can identify the orientation of the target planes 58 and automatically move the cutting tool 30 so that the orientation of the cutting tool 30 coincides with the target planes 58. In one example, the control system 32, 36 can determine a predefined tool path 62 for the cutting tool 30 to follow, the tool path 62 being designed to align the cutting tool 30 along one or more target planes 58. Once the control system 32, 36 determines the predefined tool path 62, the control system 32, 36 can automatically advance the tool 30 along the path during a surgical procedure to align the cutting tool 30 with one or more target planes 58. The tool 30 can be advanced to align with the target planes 58 according to a default feedrate predefined by the system. An operator may be able to change the default feedrate before the alignment action occurs or change the feedrate during the alignment action.

[0108] The manual mode can be used to align the tool 30 to a particular target plane(s) 58, while the automatic mode can be used to align the tool 30 to other target plane(s) 58. In some cases, the action of aligning the tool 30 to a target plane 58 may be performed exclusively in either manual mode or automatic mode. In other examples, the action of aligning the tool 30 to a target plane 58 may include a combination of sub-actions or sub-steps, with some steps selected to be performed in manual mode and other steps selected to be performed in automatic mode. For example, in one step of the alignment action, an operator may guide the tool 30 to a location remote from the anatomy in manual mode, and then in a second step, an automatic mode toolpath can be generated to advance the tool from the remote location to an aligned pose relative to the target plane 58. In another example, for one step of the alignment action, an automatic mode toolpath can be generated to advance the tool from a remote location to an aligned pose relative to the target plane 58 and to an end position a predefined distance away from the bone. Then, in a second step, the operator can navigate the tool 30 from the end position towards the anatomy in manual mode.

[0109] B. Action: Cut along the cutting surface

[0110] Another action of the cutting tool 30 that can be performed by the manipulator 20 includes the cutting tool 30 performing a resection. FIGS. 6 and 7 illustrate an example in which the control systems 32, 36 control the cutting tool 30 to resect a patient's anatomy, shown as a femur F. In the example illustrated in FIGS. 6 and 7, the cutting tool 30 resects the patient's anatomy by moving along a path 62 determined or commanded by the control systems 32, 36. In this particular example, moving the cutting tool 30 along the path 62 resects the femur F, performing a distal femoral cut DFC. Of course, other cuts can be performed using the techniques described herein. Additionally, the action of performing a resection may, but does not necessarily, require the removal of all material from the target plane 58. In other words, the resection action may include a partial resection performed by one or more cuts by the cutting tool 30. Accordingly, it is contemplated that the resection action may include one or more steps or series of actions.

[0111] To perform a resection action in automatic mode, the cutting tool 30 is activated, allowing the cutting tool 30 to remove tissue, and the cutting tool 30 moves along a predefined path 62. As shown in FIG. 6, the predefined path 62 can be a longitudinal path (y-direction, 270 degrees) along the target plane 58 that extends along the cross-sectional portion of the bone. Of course, the predefined path 62 can be oriented in a direction different from the y-direction shown. For example, the predefined path 62 can include various turns, pivot points for the cutting tool 30, and changes of direction (e.g., in the x and y directions).

[0112] In automatic mode, the cutting action can be performed by moving the cutting tool 30 in a straight line, a curved path, or a curved path (by changing the tool orientation during the cut). Thus, the plunge cut does not necessarily have to be a straight line. However, if a curved or curved path is used, the control system may determine a pre-cut based on the shape and direction of the curve to remove material and thereby allow space for the cutting tool 30 to reorient into the curve. When a pre-cut is performed, the cutting tool 30 is instructed to move along a pre-defined curved path 62.

[0113] In automatic mode, the cutting tool 30 may move along multiple predefined paths 62 to completely resect the patient's anatomy. For example, as shown in FIG. 7 , the cutting tool 30 may move along a series of predefined paths 62(1)-62(13) to resect the femur F along the target plane 58 and completely perform the distal femoral resection DFC. The predefined paths 62 may cause the tool 30 to interact with the bone by performing a series of plunge cuts, such as facing the bone, making a resection cut, retracting from the cut, then changing position to make another cut. Thus, the predefined paths 62 may define the movement path of the tool 30 in a manner related to some of the actions described herein. For example, the predefined paths 62 may define a series of actions within the same target plane 58, including multiple resection cuts, retractions, and repositioning of the tool 30.

[0114] The control system 32, 36 may determine the predefined path 62 using any suitable method. For example, the control system 32, 36 may pre-operatively and / or intra-operatively determine the predefined path 62 based on the target plane 58, the target perimeter 60, and / or the virtual boundary VB. More specifically, the control system 32, 36 may determine the predefined path 62 such that the cutting tool 30 moves along the predefined path 62 to resect the entire portion R of the patient's anatomy within the target boundary 60 while adhering to the virtual boundary VB. In some cases, the predefined path 62 may include multiple passes. For example, the predefined path 62 may include a first pass to cut the entire anatomy, followed by a finishing pass to remove any remaining portions of the region R not cut during the first pass. A removal material logger may be implemented by the control system 32, 36 to monitor the pose of the tool 30 relative to the registered bone model over time to determine what material may remain after the first pass. In other words, the control systems 32, 36 identify the volume of bone to be cut and track the volume of bone that remains uncut. Once the remaining bone portion(s) are identified, one or more predefined paths 62 are generated so that the cutting tool 30 can remove the portion(s). The removal material logger is similar to that described in U.S. Patent No. 9,119,655, entitled "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes," the entire contents of which are incorporated herein by reference.

[0115] The control systems 32, 36 may also determine the predefined path 62 to optimize the cutting efficiency of the cutting tool 30. For example, the control systems 32, 36 may determine the predefined path 62 based on the density of the patient's anatomy, the type or size of the cutting tool, and / or the shape of the patient's anatomy.

[0116] The control system 32, 36 can define a feed rate for the predefined path 62, which is the speed at which the tool 30 moves along the predefined path 62. The feed rate can be predefined based on the surgical plan or can be set by the operator before or during surgery. In some cases, the operator can control the feed rate during automated movement using a remote control or pendant, such as that described in U.S. Pat. No. 9,119,655, entitled "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes." The entire contents of this patent are incorporated herein by reference. The feed rate for the resection cut can be defined differently from the feed rate for the retraction action along the predefined path 62. For example, a slower feed rate for the cut can be used to avoid skiving or achieve a smoother cut. After the cut, a faster feed rate can be used to retract the tool 30 along the predefined path 62, expediting the process of reaching the next cut on the same target plane 58. The operator can select the feed rate before or during surgery. In some cases, a GUI may be available to allow the operator to manage the feedrate of the cutting action, or each substep of the cutting action. In some cases, the system may provide a default feedrate, allowing the operator to change the default feedrate as needed.

[0117] In manual mode, the control systems 32, 36 may move the cutting tool 30 to resect the patient's anatomy based on the forces and torques applied to the cutting tool 30 by the operator, as sensed by the force / torque sensor S. In response, the control systems 32, 36 may move the cutting tool 30 in a manner that emulates the forces and torques applied to the cutting tool 30 by the operator, to resect the patient's anatomy. Thus, the tool 30 may move along a path, but the path is dictated by the operator and not pre-defined as in automatic mode.

[0118] In manual mode, the control systems 32, 36 may prevent movement of the cutting tool 30 and / or disable actuation of the cutting tool 30 based on interaction with the virtual boundary VB. For example, in manual mode, the virtual boundary VB may define a limit beyond which the cutting tool 30 must not move or resect. If the surgeon desires to position the cutting tool 30 beyond the virtual boundary VB during resection, the control systems 32, 36 will prevent movement of the cutting tool 30 and / or disable actuation of the cutting tool 30.

[0119] In manual mode, the control systems 32, 36 also constrain movement of the cutting tool 30 to the target plane 58 when the cutting tool 30 is within the target plane 58. Thus, the control systems 32, 36 provide a tactile response and constrain the operator's ability to move the cutting tool 30 when forces and torques applied to the cutting tool 30 by the operator would otherwise cause the cutting tool 30 to collide with the target plane 58.

[0120] The manual mode may be utilized to perform resection cuts with the tool 30 on specific target plane(s) 58, and the automatic mode may be utilized to perform resection cuts with the tool 30 on other target plane(s) 58. In some cases, the action of performing resection cuts with the tool 30 may only be performed in either the manual mode or the automatic mode.

[0121] It is also possible to utilize a combination of manual and automatic modes for the resection action for a single target plane 58. For example, an action / mode combination can be selected such that an initial “bulk cut” pass is performed in manual mode and a second “finish cut” pass is performed in manual mode. In another example, the resection action can include two sub-actions to reduce the likelihood of tool skiving: (1) performing an initial cut between the cutting tool 30 and the outer (cortical) surface of the bone at an entry position relative to the target plane 58, and (2) performing a plunge-cut resection along the target plane 58 from the entry position after the initial cut. In this example, the action / mode combination can be selected such that the initial cut is performed in automatic mode and the plunge cuts are performed in either manual or automatic mode. The feed rate for the first cut in automatic mode can be defined separately from the feed rate for performing subsequent plunge cuts. For example, the feed rate for the first cut in automatic mode can be slowed to avoid skiving at the entry position. A faster feed rate can then be utilized to allow the cutting tool 30 (in either manual or automatic mode) to perform subsequent plunge cuts to expedite tissue removal. Controlling the first cut in this way can reduce the chance of tool skiving, which can be particularly advantageous when the system is performing automatic cutting without direct operator control.

[0122] The system may be configured to detect the transition between cortical and cancellous bone for purposes such as skiving mitigation. In one example, sensors can be coupled to the manipulator and / or cutting tool 30 to facilitate detection of the transition between cortical and cancellous bone. The sensors can be force / torque sensors, pressure sensors, tissue temperature sensors, current or power drawn by the cutting tool 30, etc. Additionally or alternatively, the navigation system can include patient image data (matched to the patient) that identifies the cancellous / cortical bone transition. The patient image data may include bone mineral density information, such as BMD data. The navigation system can compare the position of the cutting tool 30 to the bone transition. In any of these examples, the mode and / or feed rate can be automatically changed once the transition is detected.

[0123] For use in either manual or automatic mode, the surgical system can detect off-axis loads applied to the tool 30 using sensors on the cutting tool 30, such as a force / torque sensor S, or joint motor sensors. Off-axis loads can indicate an undesirable condition, such as deflection or skiving of the cutting tool 30. This condition is most likely to occur during the resection action as the tool 30 engages a bone region. The control system 32, 36 can measure this off-axis load for a threshold time, magnitude, and / or direction. If the control system 32, 36 determines that a threshold has been exceeded, it can command a mitigating action to the manipulator 20 and / or cutting tool 30 to mitigate the condition. In one embodiment, the mitigating action is to adjust the feed rate or penetration rate of the cutting tool 30. For example, the feed rate can be slowed to reduce the likelihood of skiving. In another example, the tool path(s) can be modified to adjust the volume of bone cut with each pass. If the toolpath passes are closer together, the cutting tool 30 will be exposed to less bone during cutting, which may reduce the likelihood of skiving occurring.

[0124] C. Action: Retract the cutting tool along the target surface

[0125] Another action of the cutting tool 30 that can be performed by the manipulator 20 is retracting the cutting tool 30. Retracting the cutting tool 30 refers to withdrawing, pulling back, turning back, or changing direction of the cutting tool 30 to move the cutting tool 30 away from the tissue resection area. Retraction may involve the cutting tool 30 exiting the bone region or may involve the cutting tool 30 remaining within the bone region. For example, a retraction action may occur after a resection action to pull back the cutting tool 30 to perform the next cutting iteration. In such a case, retraction may occur after performing a resection cut in either manual or automatic mode. In another example, retraction may occur in response to a collision with the virtual boundary VB or exceeding the target perimeter 60. A retraction action may occur while the cutting tool 30 is constrained to the target plane 58. However, retraction may occur while the cutting tool 30 is out of the constraints of the target plane 58. For example, retraction may cause the cutting tool 30 to exit the target plane 58 in preparation for alignment with another target plane 58.

[0126] 8 shows an example in which the cutting tool 30 is controlled to retract along the target plane 58. The cutting tool 30 retracts by moving along a retract path as indicated by arrow 64. The retract direction may differ from that shown. The cutting tool 30 can retract from any pose (position and / or orientation) within the target plane 58.

[0127] In automatic mode, the control system 32, 36 may be configured to automatically retract the cutting tool 30 along predefined retraction path(s). The control system 32, 36 may determine the predefined retraction path using any suitable method. For example, the control system 32, 36 may limit or define the predefined retraction path in one or more of the following ways: retracting along the target plane 58; avoiding collisions or potential collisions between any portion of the cutting tool 30 and other objects (e.g., the virtual boundary VB or anatomy); retracting the cutting tool 30 within the target perimeter 60; retracting the cutting tool 30 from its last, deepest cutting point; retracting the cutting tool 30 a predetermined retraction distance, e.g., 100 mm; retracting the cutting tool 30 to exit an anatomical region of the anatomy (e.g., in preparation for alignment to another target plane); retracting the cutting tool 30 in a straight line, a curved path, or a curved path (changing the tool orientation during retraction); retracting the cutting tool 30 in a straight line, a curved path, or a curved path; retracting the cutting tool 30 to the start of a subsequent cutting path, etc.

[0128] The control system 32, 36 can define the feedrate for the retract path 64, which is the speed at which the cutting tool 30 retracts along the path 64. The feedrate can be predefined based on the surgical plan or can be set by the operator before or during the retraction. In some cases, the operator can control the feedrate during automated movements using, for example, a remote control or pendant, such as that described in U.S. Pat. No. 9,119,655, entitled "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes." The entire contents of this patent are incorporated herein by reference. The retraction feedrate can be defined differently from the feedrate for the resection cut action along the tool path 62. For example, the retraction feedrate can be faster to expedite the process of reaching the next cut on the same target plane 58. The operator can select the retraction feedrate preoperatively or intraoperatively. In some cases, a GUI can be utilized to allow the operator to manage the retraction action feedrate or each substep of the retraction action. In some cases, the system provides a default feedrate, allowing the operator to change the default feedrate as needed.

[0129] During retraction in automatic mode, the cutting tool 30 may be activated or deactivated. The control systems 32, 36 allow the surgeon to configure a setting for activating or deactivating the cutting tool 30 during retraction. Alternatively, this may be a default setting for the surgical plan.

[0130] In manual mode, the control systems 32, 36 may retract the cutting tool 30 based on the force and torque applied to the cutting tool 30 by the operator as sensed by the force / torque sensor S. In response, the control systems 32, 36 may retract the cutting tool 30 in a manner that emulates the force and torque applied to the cutting tool 30 by the operator to retract the patient's anatomy.

[0131] In manual mode, the control systems 32, 36 may prevent movement of the cutting tool 30 based on interaction with the virtual boundary VB. For example, in manual mode, the virtual boundary VB may define a limit beyond which the cutting tool 30 must not be moved or retracted. If the practitioner wishes to retract the cutting tool 30 beyond the virtual boundary VB, the control systems 32, 36 will prevent movement of the cutting tool 30.

[0132] In manual mode, the control systems 32, 36 also constrain movement of the cutting tool 30 to the target plane 58 when the cutting tool 30 is within the target plane 58. Thus, the control systems 32, 36 provide a tactile response and constrain the operator's ability to move the tool 30 when forces and torques applied by the operator to the cutting tool 30 would otherwise cause the cutting tool 30 to collide with the target plane 58. However, assuming there is no collision with the target plane 58, the control systems 32, 36 enable a retract action of the cutting tool 30, allowing the operator to manually retract the tool 30 relative to the target plane 58.

[0133] In manual mode, it may be useful to limit the way the operator can retract the tool 30. For example, input from the force / torque sensor S may be utilized by the control systems 32, 36 to compare the direction of resection with the direction of subsequent retraction. If the directions are opposite to each other within a threshold, the control systems 32, 36 may allow manual retraction. On the other hand, if the retraction direction differs from the resection direction by a threshold, the control systems 32, 36 may apply a virtual constraint to the tool 30 to limit the retraction direction to be opposite to the resection direction.

[0134] The manual mode may be utilized to perform a retract action by the tool 30 relative to a particular target plane(s) 58, while the automatic mode may be utilized to perform a retract action by the tool 30 relative to another target plane(s) 58. In some cases, the retract action of the tool 30 may be performed exclusively in either the manual mode or the automatic mode. It is also possible that a combination of manual and automatic modes may be utilized for a single target plane 58. For example, an action / mode combination may be selected such that a first "bulk cut" pass is performed in manual mode and a second "finish cut" pass is performed in manual mode. The manual retract occurs during the bulk cut and the automatic retract occurs during the finish cut.

[0135] D. Action: Changing the orientation of the cutting tool relative to the target plane

[0136] Another action of the cutting tool 30 that can be performed by the manipulator 20 includes changing the pose of the cutting tool 30. To change the pose of the cutting tool 30, the manipulator 20 changes the orientation and / or position of the cutting tool 30. A change of pose action can occur when the cutting tool 30 is inside, outside, or partially within a bone region. For example, a change of pose action may occur after a resection or retraction action to change the position / orientation of the cutting tool 30 to perform the next cutting iteration. In such a case, a change of pose action may occur after performing a resection or retraction action in either manual or automatic mode. In another example, a change of pose action may occur in response to a collision with the virtual boundary VB or exceeding the target perimeter 60. A change of pose action may occur while the cutting tool 30 is constrained to the target plane 58. However, a change of pose action may occur while the cutting tool 30 is outside the constraints of the target plane 58. For example, a change of pose action may occur outside the target plane 58 in preparation for alignment with another target plane 58.

[0137] FIGS. 7, 9, and 10 illustrate various examples of changing the orientation of the cutting tool 30. Referring to FIG. 7, the control system 32, 36 commands the manipulator 20 to change the position of the cutting tool 30 by moving the tool 30 in the X direction while maintaining its orientation in the Y direction. This change in position can be performed for a variety of reasons, such as preparing the tool 30 to perform a series of linear cuts. In FIG. 9, the manipulator 20 is instructed to control the cutting tool 30 to cut along a first predetermined path 62(1) and then change the orientation of the cutting tool 30 to prepare the cutting tool 30 to cut along a second predetermined path 62(2). As shown, the orientation of the cutting tool 30 is changed from 250 degrees to 290 degrees relative to the x-y coordinate system of the target plane 58. In FIG. 10, the orientation is changed by changing the orientation of the cutting tool 30 while cutting along the predefined path 62. Here, the cutting tool 30 first follows a straight path 62 along the Y direction (270 degrees) and then turns towards the X direction (180 degrees) to form a curved resection path 62 .

[0138] In the automatic mode, the control system 32, 36 may be configured to automatically reorient the cutting tool 30 via an automatic reorientation action. The control systems 32, 36 can determine the movement and / or timing of automatic reorientation actions based on various inputs or events, such as to change orientation to facilitate exiting a region of the anatomy (e.g., in preparation for alignment with another target plane), change orientation before, during, or after a retraction action, change orientation before, during, or after a cutting action, change orientation before, during, or after alignment with a target plane, change orientation within or outside of the target plane 58, avoid a collision or potential collision between the cutting tool 30 and other objects (such as the virtual boundary VB or anatomy), change orientation to maintain the cutting tool 30 within the target perimeter 60, change orientation to follow a predefined cutting path, reposition the cutting tool 30 by a predetermined displacement, e.g., 100 mm, change the orientation of the cutting tool 30 by a predetermined angle, e.g., 15 degrees, change the orientation of the cutting tool 30 toward the start of a subsequent cutting path, etc.

[0139] The parameters of the automatic reorientation action may be determined based on the surgical plan, surgeon preference, tool geometry, anatomical geometry, manipulator constraints, etc. During the automatic reorientation action in automatic mode, the cutting tool 30 may be activated or deactivated. The control systems 32, 36 allow the surgeon to configure settings for activating or deactivating the cutting tool 30 during reorientation. Alternatively, this may be a default setting for the surgical plan.

[0140] In manual mode, the control systems 32, 36 may change the attitude of the cutting tool 30 based on the forces and torques applied to the cutting tool 30 by an operator as sensed by the force / torque sensor S. In response, the control systems 32, 36 may change the attitude of the cutting tool 30 in a manner that emulates the forces and torques applied to the cutting tool 30 by the operator when making the change in attitude.

[0141] In manual mode, the control systems 32, 36 may prevent reorientation of the cutting tool 30 based on interaction with the virtual boundary VB. For example, in manual mode, the virtual boundary VB may define limits within which the cutting tool 30 must not move or reorient. If the practitioner wishes to reorient the cutting tool 30 beyond the virtual boundary VB, the control systems 32, 36 will prevent movement of the cutting tool 30.

[0142] In manual mode, the control systems 32, 36 also constrain the movement of the cutting tool 30 to the target plane 58 when the cutting tool 30 is within the target plane 58. Thus, the control systems 32, 36 provide a tactile response and constrain the operator's ability to change the orientation of the tool 30 when forces and torques applied to the cutting tool 30 by the operator would otherwise cause the cutting tool 30 to collide with the target plane 58.

[0143] The manual mode may be utilized to perform reorientation actions by the tool 30 relative to specific target plane(s) 58, and the automatic mode may be utilized to perform automatic reorientation actions by the tool 30 relative to other target plane(s) 58. In some cases, reorientation actions of the tool 30 may be performed exclusively in either manual mode or automatic mode. It is also possible that a combination of manual and automatic modes may be utilized for a single target plane 58. For example, an action / mode combination may be selected such that a first "bulk cut" pass is performed in manual mode and a second "finish cut" pass is performed in manual mode. Manual reorientation actions occur during bulk cuts, and automatic reorientation actions occur during finish cuts.

[0144] E. Context-aware switching of manual / automated surgical actions

[0145] Any of the manual / automated surgical actions described above may be automatically triggered when the control system 32, 36 detects a predefined behavior, a situational context, or the completion of one or more steps. For example, the control system 32, 36 may automatically switch between a resection action and a retract action. The resection action may be identified as completed by the control system 32, 36 in response to various inputs. For example, the control system 32, 36 may sense activity related to pressing the tool 30 trigger or collision of the tool 30 with the virtual boundary VB by monitoring the amount of material removed by the tool 30 from the target plane 58 or by monitoring the path of the tool 30 relative to the surgical plan. Using one or more of these inputs, the control system 32, 36 may infer that the resection action is complete and trigger an automatic switch to a retract action. The retract action may be performed manually or automatically, depending on the configuration. Switching by the control system 32, 36 may include not only switching actions but also automatically switching modes (e.g., between manual and automatic modes, or vice versa). For example, the cutting action can be performed in manual mode, and after the control system 32, 36 detects a predetermined behavior, the control system 32, 36 can switch to automatic mode to perform retraction and / or reorientation of the tool 30. In some cases, a specific input may be required to change actions or modes. For example, before switching from manual cutting to automatic retraction, the control system 32, 36 may require the tool 30 to reach or collide with a virtual boundary VB (indicating that full retraction has been completed). Additionally, or alternatively, before switching from manual cutting to automatic retraction, the control system 32, 36 may need to detect the start of a manual retraction action and then automatically take over the retraction action. In yet another example, the control system 32, 36 may trigger automatic repositioning to another cutting plane by detecting that a required amount of material has been removed from the current target plane 58.To implement the above techniques, any combination of predefined behaviors, situational contexts, or completion of one or more steps can be utilized with any combination of surgical procedures described herein.

[0146] F. Anatomical Considerations for Manual / Automated Surgical Actions

[0147] One additional input or variable that may alter the behavior of the manipulator 20 when performing any of the manual or automated surgical actions described above is tracking, sensing, imaging, or modeling of bone or soft tissue at the surgical site. The bone and / or soft tissue can be imaged preoperatively or intraoperatively using any imaging modality, such as a CT scan, X-ray, ultrasound, or machine vision. In some cases, the bone and / or soft tissue image data can be converted into a 3D model, geometric model, mesh, or point cloud. A segmentation process can be used to convert slices of the image data into a model. The soft tissue can be identified to determine sensitive structures surrounding the bone. These structures could be ligaments, surrounding soft tissue, or incisions at the surgical site. The bone or soft tissue model can be used as a reference for creating a surgical plan, and a navigation system can be used to align the model to the actual patient anatomy. In some cases, image-less registration techniques can be used, using a pointer (P) to digitize various points on the bone or soft tissue to form a model during surgery.

[0148] A navigation system can also be used to track the patient's incision and associate a virtual boundary with the incision. Incision tracking can be achieved by tracking elements coupled to retractors holding the incision open or by using fiber optic cables attached to the skin surrounding the incision opening. In another example, a machine vision system can be utilized to track the incision. The machine vision system can be implemented as a camera coupled to the manipulator 20 and / or the localizer. In one embodiment, the machine vision system identifies the incision opening or image and identifies surrounding retractors, allowing for the creation of a virtual constraint boundary associated with the incision. In another embodiment, a machine vision system is utilized in conjunction with a navigation system. The machine vision system images the soft tissue and bone in the machine vision camera's coordinate system. The navigation system tracks the bone in the localizer coordinate system. The localizer data is combined with the machine vision image data into a common coordinate system and merged to identify data points in the image data with coordinates that lie outside the aligned bone model. These outside coordinates represent the soft tissue surrounding the bone. Associating virtual objects with soft tissue can define areas outside of the bone region that are avoided by the cutting tool 30. The incision tracking utilized by the techniques described herein can be similar to that described in U.S. Patent No. 9,603,665, entitled "Systems And Methods For Establishing Virtual Constraint Boundaries," or that described in U.S. Patent No. 10,667,868, entitled "System And Methods For Performing Surgery On A Patient At A Target Site Defined By A Virtual Object."

[0149] In one embodiment, a navigation probe (P) is utilized to define virtual boundaries during surgery. This technique may be effective for soft tissue structures such as ligaments, patellas, and incision openings. The probe (P) is tracked by a navigation system, and digitized or touched points of the probe tip are recorded. The operator can trigger or record touch points using a user interface (UI), a display, or controls on the probe (P). A computer model of the anatomical location of the anatomy and the movement of the probe (P) relative to that location can be displayed on the display. Once a sufficient number of points have been recorded, the soft tissue boundaries can be established. This technique can be performed regardless of whether the anatomy is directly or continuously tracked. For example, if the anatomy is not tracked, the pointer (P) can be used to reestablish the soft tissue boundaries if the operator determines that the anatomy has moved since the last registration. Bone tracking allows the soft tissue boundaries to be established and maintained in relation to bones, even if the anatomy has moved.

[0150] By understanding the relationship of the soft tissue or incision to the bone being treated, the control systems 32, 36 can provide additional input to manage or control the above-described operations of the cutting tool 30, i.e., alignment to the target plane, resection, retraction, and reorientation of the cutting tool 30. For example, virtual boundaries associated with the soft tissue may change how the tool 30 is oriented in either mode. In automatic mode, the soft tissue boundaries may provide constraints, and the control systems 32, 36 redefine the allowable reorientation of the tool 30 between resection cuts to avoid collisions with the soft tissue. In manual mode, the soft tissue boundaries act as virtual boundaries, restricting the movement of the tool 30 from meeting or exceeding the boundaries, or deactivating the tool 30.

[0151] Furthermore, in some embodiments, the resection of anatomy by the cutting tool can be monitored without using a bone model or directly tracking bone with a navigation system. Here, the incision area can be identified using any of the techniques described above. The surgical system can use one or more sensors to detect when the cutting tool 30 is fully inserted into the bone area. The sensors can detect changes in power to the cutting tool 30, monitor vibration of the cutting tool 30 during cutting (e.g., less vibration when cutting compared to moving through air), and / or monitor force measurements on the cutting tool 30 and / or manipulator 20. Without using a bone model, the control systems 32, 36 can receive sensor measurements to determine or infer the relationship between the cutting tool 30 and bone. For example, the control systems 32, 36 can determine whether the cutting tool 30 is entering, passing through, or exiting the cortical bone (or surrounding the target), or cutting soft tissue. Any of these sensing techniques may be utilized in any of the operations of the cutting tool 30 described above, whether used in manual or automatic mode.

[0152] In the foregoing description, several embodiments have been discussed. However, the embodiments discussed herein are not intended to be exhaustive or to limit the invention to any particular form. The terminology used is intended to be in the nature of words descriptive rather than limiting. Many modifications and variations are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described.

Claims

1. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; controlling the manipulator to align the cutting tool with the target plane; The manipulator is operated in an automatic mode by at least one of the following: automatically cutting along the target plane using the cutting tool; automatically retracting the cutting tool along the target plane; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of at least one of the following: the control system configured to: The robotic surgery system comprises:

2. The robotic surgical system of claim 1 , wherein the control system is configured to associate a target perimeter with the anatomical structure, the target perimeter being disposed within the target plane and corresponding to a perimeter of a portion of the anatomical structure.

3. 3. The robotic surgical system of claim 2, wherein the control system is configured to associate a virtual boundary with the anatomical structure, the virtual boundary being located within the target plane and based on the target perimeter; the manipulator is configured to resect along the target plane with the cutting tool in response to the cutting tool being located within the virtual boundary; and the manipulator is configured to deactivate or retract the cutting tool in response to the cutting tool reaching or crossing the virtual boundary.

4. the control system controlling the manipulator in a manual mode to align the cutting tool with the target plane; the manipulator in an automatic mode; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically retracting the cutting tool along the target plane; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

5. the control system controlling the manipulator in a manual mode to resect the anatomical structure along the target surface using the cutting tool; the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically retracting the cutting tool along the target plane; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

6. the control system controlling the manipulator in a manual mode to retract the cutting tool along the target plane; the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

7. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; and controlling the execution of the the manipulator in an automatic mode; automatically retracting the cutting tool along the target plane; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

8. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; retracting the cutting tool along the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

9. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; changing the orientation of the cutting tool on the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically retracting the cutting tool along the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

10. the control system The manipulator is in a manual mode. ablating the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically changing the orientation of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

11. the control system The manipulator is in a manual mode. ablating the anatomical structure along the target plane using the cutting tool; changing the orientation of the cutting tool on the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically retracting the cutting tool along the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

12. the control system The manipulator is in a manual mode. retracting the cutting tool along the target plane; changing the orientation of the cutting tool on the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically cutting the anatomical structure along the target plane using the cutting tool; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

13. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically changing the pose of the cutting tool on the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

14. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; changing the orientation of the cutting tool on the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically retracting the cutting tool along the target plane; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

15. the control system The manipulator is in a manual mode. aligning the cutting tool with the target plane; retracting the cutting tool along the target plane; changing the orientation of the cutting tool on the target plane; and controlling the execution of the the manipulator in an automatic mode; automatically cutting the anatomical structure along the target plane using the cutting tool; and controlling the execution of the The robotic surgery system of claim 1 , configured to:

16. The robotic surgical system of claim 1 , wherein the control system is configured to control the manipulator in the automatic mode by automatically moving the cutting tool along a predetermined tool path.

17. 10. The robotic surgical system of claim 1, further comprising a force / torque sensor configured to sense a force / torque applied to the cutting tool by an operator, and wherein the control system is configured to command movement of the cutting tool in response to the sensed force / torque, thereby controlling the manipulator in a manual mode.

18. and a user interface coupled to the control system, the user interface allowing an operator to selectively pre-assign manual or automatic mode control to at least one of the following: aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; changing the orientation of the cutting tool on the target plane; The robotic surgery system of claim 1 , configured to perform at least one of the following:

19. ablating the anatomical structure includes performing a plurality of ablations, each ablation occurring on a target plane different from the target planes of the other ablations, and for each ablation, the user interface allows an operator to selectively pre-assign manual or automatic mode control to at least one of the following: aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; changing the orientation of the cutting tool on the target plane; 20. The robotic surgery system of claim 18, configured to perform at least one of the following:

20. The control system automatically and selectively pre-assigns manual or automatic mode control to at least one of the following: aligning the cutting tool with the target plane; ablating the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; changing the orientation of the cutting tool on the target plane; 10. The robotic surgery system of any preceding claim, configured to perform at least one of:

21. the control system controlling the manipulator in a manual mode to perform one of the following actions: aligning the cutting tool with the target plane; resecting the anatomical structure along the target plane using the cutting tool; retracting the cutting tool along the target plane; and changing the orientation of the cutting tool on the target plane; detecting an occurrence of a predefined behavior of the cutting tool during execution of the action; controlling the manipulator to automatically switch between performing different actions from the plurality of actions in response to detecting the predefined behavior; 10. A robotic surgery system according to any preceding claim, configured to:

22. 22. The robotic surgery system of claim 21, wherein in response to detecting the predefined behavior, the control system is configured to automatically switch from the manual mode to the automatic mode so as to further control the manipulator to automatically perform the different behavior.

23. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; the manipulator in an automatic mode; automatically aligning the cutting tool with the target plane; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically retracting the cutting tool along the target plane; automatically changing the orientation of the cutting tool on the target plane; and the control system configured to: The robotic surgery system comprises:

24. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; The manipulator is operated in an automatic mode by at least one of the following: automatically aligning the cutting tool with the target plane; automatically cutting the anatomical structure along the target plane using the cutting tool; automatically retracting the cutting tool along the target plane; and controlling the execution of at least one of the following: The manipulator is in a manual mode. changing the orientation of the cutting tool on the target plane; and controlling the execution of the the control system configured to: The robotic surgery system comprises:

25. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; moving the cutting tool in one or both of a manual mode and an automatic mode to control the manipulator to perform one or more actions including aligning the cutting tool with the target plane, using the cutting tool to resect the anatomical structure along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane; the control system configured to: a user interface coupled to the control system, the user interface configured to allow an operator to selectively pre-assign the one or more action(s) to be performed in either the manual mode or the automatic mode; and The robotic surgery system comprises:

26. 1. A robotic surgery system, comprising: A cutting tool; a manipulator configured to support the cutting tool; A user interface; 1. A control system comprising: controlling the manipulator to move the cutting tool to perform a plurality of different actions; receiving input from the user interface for selectively pre-assigning one or more of a plurality of different action(s) to be performed in either a manual or automatic mode of operation; the control system configured to: The robotic surgery system comprises:

27. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; controlling the manipulator to move the cutting tool in one or both of a manual mode and an automatic mode to perform actions including aligning the cutting tool with the target plane, using the cutting tool to resect the anatomical structure along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane; automatically pre-assigning one or more of the actions to be performed in either the manual mode or the automatic mode; controlling the manipulator to move the cutting tool to perform one or more of the actions according to the pre-assigned mode; the control system configured to: The robotic surgery system comprises:

28. 1. A robotic surgery system, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: obtaining a plurality of actions to be performed by the manipulator moving the cutting tool; Selectively pre-assigning one or more of said actions to be performed in either a manual or an automatic mode of operation; controlling the manipulator to move the cutting tool to perform one or more of the actions according to the pre-assigned mode; the control system configured to: The robotic surgery system comprises:

29. 1. A robotic surgical system for resecting a anatomical structure, comprising: A cutting tool; a manipulator configured to move the cutting tool; 1. A control system comprising: associating a target plane with the anatomy, the target plane separating a portion of the anatomy to be ablated from a portion of the anatomy that is to remain unablated; controlling the manipulator to move the cutting tool in an automatic mode to perform one or more actions including aligning the cutting tool with the target plane, using the cutting tool to resect the anatomical structure along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane; the control system configured to: a user interface coupled to the control system, the user interface configured to allow an operator to selectively pre-assign a feed rate of the cutting tool to any one or more of the actions; and The robotic surgery system comprises:

30. 1. A robotic surgery system, comprising: a surgical saw configured to cut bone; a manipulator configured to move the surgical saw; 1. A control system comprising: associating a target plane with the bone, the target plane separating a portion of the bone to be resected from a portion of the bone that is to remain unresected; controlling the manipulator to align the surgical saw with the target plane; controlling the manipulator in an automatic mode to first penetrate a cortical surface of the bone according to a first feed rate to automatically cut the bone along the target plane with the surgical saw; controlling the manipulator to initially penetrate the cortical surface with the surgical saw and then resect the bone along the target plane with the surgical saw according to a second feed rate that is faster than the first feed rate; the control system configured to: The robotic surgery system comprises:

31. the control system controlling the manipulator in the automatic mode to first penetrate the cortical surface of the bone according to the first feed rate until the surgical saw reaches a predetermined depth to automatically cut the bone along the target plane with the surgical saw; After reaching the predetermined depth, controlling the manipulator to resect the bone along the target plane with the surgical saw according to the second feed rate; 31. The robotic surgery system of claim 30 configured to:

32. a sensing system configured to detect a characteristic of the bone, the control system further comprising: controlling the manipulator in the automatic mode to first penetrate the cortical surface of the bone according to the first feed rate to automatically cut the bone along the target plane with the surgical saw; determining from the sensing system that the surgical saw has broken through the cortical surface of the bone; in response to detecting breakthrough of the cortical surface, controlling the manipulator to resect the bone along the target plane with the surgical saw according to the second feed rate; The robotic surgery system according to any one of claims 30 to 31, configured to perform the following:

33. 1. A robotic surgery system, comprising: A cutting tool; a manipulator configured to support the cutting tool; 1. A control system comprising: controlling the manipulator in either an automatic mode or a manual mode to perform an action from a plurality of different actions; detecting an occurrence of a predefined behavior of the cutting tool during execution of the action; controlling the manipulator to automatically switch to a different action in response to detecting the predefined behavior; the control system configured to: The robotic surgery system comprises:

34. 34. The robotic surgical system of claim 33, wherein the control system is configured to associate a target plane with the anatomy.

35. the action includes one of the following: aligning the cutting tool with the target plane; using the cutting tool to cut along the target plane; retracting the cutting tool along the target plane; and changing the orientation of the cutting tool on the target plane; 35. The robotic surgical system of claim 34, wherein the different actions include different ones of the following: aligning the cutting tool with the target plane, using the cutting tool to cut along the target plane, retracting the cutting tool along the target plane, and changing the orientation of the cutting tool on the target plane.

36. the control system controlling the manipulator in the manual mode to perform the action; Detecting an occurrence of the predefined behavior while performing the action in the manual mode; controlling the manipulator to automatically switch to the different action and automatically switch from the manual mode to the automatic mode in response to detecting the predefined behavior; The robotic surgery system of any one of claims 33 to 35, configured to perform the following:

37. 37. The robotic surgical system of claim 34, wherein the predefined behavior includes at least one of the following: a collision of the cutting tool with a virtual boundary, a change in direction of the cutting tool, and the cutting tool removing a predefined amount of material from the target plane.

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