Robotic spinal surgery system and method with haptic interface

Abstract

Disclosed herein is technology including a robotic manipulator including a surgical tool coupled to a screw for rotating the screw about a rotation axis. The haptic device includes an actuator and a rotation interface coupled to the actuator, the rotation interface being manually operable by an operator's hand. One or more controllers control the movement of the robotic manipulator to maintain the rotation axis of the surgical tool along a planned trajectory, autonomously control the surgical tool to rotate the screw at a rotational speed about the rotation axis, linearly advance the screw at an advancement speed according to the screw's known thread profile, obtain measurements indicative of a current interaction between the screw and the target site, and control the actuator of the haptic device to enable the rotation interface to emulate the current interaction between the screw and the target site.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the full benefit of U.S. Provisional Patent Application No. 63 / 001,019, filed March 27, 2020, the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] Robotic surgical systems for performing surgical procedures on a patient's spine are well known. For example, robotic surgical systems are currently utilized to place pedicle screws in a patient's spine.

[0003] When a patient requires surgery involving pedicle screw placement, pre-operative and / or intra-operative imaging is often used to visualize the patient's anatomy (in this case, the patient's spine) requiring treatment. The surgeon then plans where the pedicle screws should be placed with respect to the images and / or a 3D model created from the images. This can involve, for example, determining the location and orientation (i.e., pose) of each pedicle screw relative to the particular vertebra in which it is being placed by identifying the desired pose within the images and / or the 3D model. Once such a plan is established, it is transferred to a robotic surgical system for execution.

[0004] Typically, a robotic surgical system includes a robotic manipulator that positions a tool guide above the patient along a desired trajectory that aligns with the desired orientation of the pedicle screw to be placed. The robotic surgical system also includes a navigation system that determines the position of the tool guide relative to the patient's anatomy so that the robotic manipulator can place the tool guide along the desired trajectory according to the surgeon's plan. In some cases, the navigation system includes tracking devices attached to the manipulator and the patient, allowing the robotic surgical system to monitor and respond to patient movement during surgery by moving the tool guide as needed to maintain the desired trajectory.

[0005] Once the tool guide is positioned to align with the desired trajectory, the robotic manipulator is controlled to maintain the alignment. The surgeon then positions a cannula adjacent to the vertebra through the tool guide. The surgeon inserts a conventional drilling tool into the cannula and drills pilot holes for the pedicle screws. The surgeon then removes the drilling tool and uses a pedicle screwdriver to insert the pedicle screws into place within the pilot holes. This method does not utilize the robotic manipulator much, as it plays little or no role in drilling the pilot holes or inserting the pedicle screws.

[0006] On the other hand, U.S. Patent No. 16 / 184,376, filed November 8, 2018, entitled "Robotic Spine Surgery System and Methods," discloses a technology that utilizes a robotic system to autonomously control surgical tools to rotate a screw at a rotational speed about a rotation axis and linearly advance the screw at an advancement speed along a planned trajectory. Despite utilizing a robotic manipulator in this methodology, the surgeon lacks direct contact with or control over the flow of force, energy, material, and information involved during tissue interaction. This, in turn, can lead to a loss of tactile and sensory information that surgeons are accustomed to using to monitor and evaluate tissue interaction processes during surgery. The surgeon's inability to evaluate the process due to a lack of sensory input can lead, among other things, to a loss of surgeon confidence, emotional stress, inadequate procedural effectiveness, and an inability to respond to unexpected situations that would otherwise be recognizable to the surgeon but not captured by a robotic solution. Summary of the Invention [Problem to be solved by the invention]

[0007] A first aspect of the present disclosure provides a robotic surgery system including: a robotic manipulator; a surgical tool coupled to the robotic manipulator and configured to couple with a screw and rotate the screw about a rotation axis; a haptic device including an actuator and a rotation interface coupled to the actuator, the rotation interface configured to be manually operable by a hand of an operator; a navigation system configured to track a position of a target site; and one or more controllers coupled to the robotic manipulator, the haptic device, and the navigation system, wherein the one or more controllers are configured to move the robotic manipulator along a planned trajectory relative to the target site based on the tracked position of the target site. and autonomously controlling the surgical tool to rotate the screw at a rotational rate about the rotational axis and linearly advance the screw at an advancement rate along a planned trajectory, the rotational rate and advancement rate being predefined and proportional to a known thread form of the screw; acquiring measurements indicative of a current interaction between the screw and the target site; and, based on the acquired measurements, controlling a haptic device to enable a rotational interface to emulate the current interaction between the screw and the target site.

[0008] In some embodiments, the rotary interface includes, but is not limited to, one or more of a knob, a wheel, a rotary switch, or a dial.

[0009] In some implementations, instead of a rotary interface, the haptic device includes a linear interface, such as, but not limited to, a linear push button, a linear switch, a linear trigger, or a linear slider.

[0010] In some embodiments, the one or more controllers are configured to control actuators of the haptic device to emulate the current interaction between the screw and the target site.

[0011] In some embodiments, the one or more controllers are configured to provide a resistance force to the actuator to adjust the force required to manually rotate the rotation interface by an operator, thereby further emulating the current interaction between the screw and the target site, wherein the force required to rotate the rotation interface reflects the current force required to rotate the screw relative to the target site.

[0012] In some implementations, the one or more controllers are configured to resist mechanical movement of the interface using means other than or in addition to actuators. For example, to resist the effects of interface movement, the haptic device may utilize mechanical components, including but not limited to biasing mechanisms, detents, ratchets and / or gear systems, electrical components, including but not limited to inductive, capacitive and / or resistive elements, magnetic components, electromagnetic components, electromechanical components, hydraulic components and / or pneumatic components.

[0013] In some embodiments, the one or more controllers are configured to limit the range of motion of the interface, thereby further emulating the current interaction between the screw and the target site.

[0014] In some embodiments, the one or more controllers are further configured to initiate an autonomous check mode, wherein the rotation interface is manually operable according to the adjusted force without the ability to control a surgical tool to rotate the screw, to provide the operator with tactile feedback reflecting the current force required to rotate the screw relative to the target site.

[0015] In some embodiments, in response to a condition or command, the one or more controllers are further configured to autonomously control the surgical tool while simultaneously initiating an autonomous check mode.

[0016] In some embodiments, in response to a condition or command, the one or more controllers are further configured to stop or pause autonomously controlling the surgical tool to stop rotation of the screw and then initiate an autonomous check mode.

[0017] In some embodiments, in response to a condition or command, the one or more controllers are further configured to stop or pause autonomous control of the surgical tool to stop rotating the screw, and then resume autonomous control of the surgical tool to rotate the screw.

[0018] In some embodiments, the one or more controllers are further configured to initiate a manual control mode, wherein the rotational interface is manually operable with the ability to control one of the screw rotation speed or the screw advancement speed based on an operator manually manipulating the rotational interface, and the one or more controllers are configured to control the surgical tool to rotate the screw at a rotational speed about the rotation axis and linearly advance the screw at an advancement speed along the planned trajectory in response to the rotational interface being manually manipulated to control one of the screw rotation speed or the screw advancement speed, and the rotational interface is manually operable according to the adjusted force and provides tactile feedback to the operator reflecting the current force required to rotate the screw relative to the target site.

[0019] In some embodiments, in response to a condition or command, the one or more controllers are further configured to stop or pause autonomously controlling the surgical tool to stop rotation of the screw and then initiate a manual control mode.

[0020] In some embodiments, in response to a condition or command, the one or more controllers are further configured to switch from the manual control mode to resume autonomously controlling the surgical tool to rotate the screw.

[0021] In some implementations, the haptic device is configured to trigger a condition or command.

[0022] In some embodiments, the robotic surgical system further includes a sensor configured to obtain measurements indicative of a current interaction between the screw and the target site, wherein the one or more controllers are coupled to the sensor.

[0023] In some embodiments, the one or more controllers are configured to determine that a condition exists during control of the screw, and in response to determining that the condition exists, provide haptic feedback to the operator regarding the condition by impeding the ability to control the actuator of the haptic device to rotate the rotation interface.

[0024] In some embodiments, the navigation system is further configured to determine a position of a screw relative to an anatomical model of the target site registered to the target site, the navigation system including predetermined data indicative of an expected interaction between the screw and the anatomical model at multiple positions of the screw relative to the anatomical model, and obtain the measurements indicative of the current interaction between the screw and the target site based on the determined position of the screw relative to the anatomical model and the predetermined data.

[0025] In some embodiments, the rotational speed and the advancement speed are related.

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[0026] In some embodiments, the tactile device is further defined as a handheld pendant.

[0027] In some implementations, the tactile device is a rotary interface such as, but not limited to, a knob, rotary switch, or dial.

[0028] In some embodiments, any implant can be utilized in place of the screw, such as a spinal implant such as a rod, anchor, spacer, cage or plate.

[0029] In some embodiments, the screw is more specifically a self-tapping screw.

[0030] In some implementations, the haptic device is located remotely and spaced apart from the robotic manipulator and surgical tool.

[0031] In some embodiments, the haptic device is attached directly to a robotic manipulator or surgical tool.

[0032] In some embodiments, the one or more controllers are further configured to receive input from an operator and selectively adjust one or more of the resistance force provided to the actuator and the sensitivity of the ability of the rotation interface to control the surgical tool to rotate the screw.

[0033] In some embodiments, the robotic surgical system further includes a display, and the one or more controllers are further configured to initiate a simulated autonomous check mode, wherein the one or more controllers are configured to: simulate autonomously controlling the surgical tool by rotating the screw at a rotational speed about the rotation axis and linearly advancing the screw at an advancement speed along the planned trajectory; display the simulated autonomous control of the surgical tool on the display; obtain a simulated current interaction between the screw and the target site; and, based on the simulated current interaction, control an actuator of the haptic device to enable the rotational interface to emulate the simulated current interaction between the screw and the target site by configuring the actuator to provide a resistance force to the actuator to adjust a force required to rotate the rotational interface by an operator's hand, wherein the force required to rotate the rotational interface reflects a simulated current force required to rotate the screw relative to the target site; and the rotational interface is manually operable without an ability to control the surgical tool to rotate the screw according to the adjusted force to provide haptic feedback to the operator reflecting the simulated current force.

[0034] In some embodiments, the one or more controllers are further configured to initiate a simulated autonomous check mode before autonomously controlling the surgical tool.

[0035] In some embodiments, the robotic surgical system further includes a display, and the one or more controllers are further configured to initiate a simulated manual control mode, wherein the rotational interface is manually operable with the ability to control one of a screw rotational speed or a screw advancement speed during the simulated manual control of the surgical tool based on an operator manually manipulating the rotational interface without the ability to control the surgical tool to rotate the screw, and the one or more controllers simulate manual control of the surgical tool by rotating the screw at a rotational speed about a rotational axis and linearly advancing the screw at an advancement speed along a planned trajectory in response to the rotational interface being manually manipulated to control one of the screw rotational speed or the screw advancement speed. and displaying simulated manual control of the surgical tool on a display; obtaining a simulated current interaction between the screw and the target site; and controlling an actuator of the haptic device based on the simulated current interaction, such that the rotational interface is configured to provide a resistance force to the actuator to adjust a force required to rotate the rotational interface by an operator's hand, thereby enabling the simulated current interaction between the screw and the target site to be emulated, wherein the force required to rotate the rotational interface reflects the simulated current force required to rotate the screw relative to the target site, and the rotational interface is manually operable according to the adjusted force to provide haptic feedback to the operator reflecting the simulated current force.

[0036] In some embodiments, in response to a condition or command, the one or more controllers are further configured to stop or pause autonomously controlling the surgical tool to stop the rotation of the screw and then initiate a simulated manual control mode.

[0037] A second aspect of the present disclosure includes a method of operating a robotic surgical system according to the first aspect of the present disclosure and, optionally, according to any embodiment in this section. The first and second aspects of the present disclosure are optionally implemented according to any of the embodiments in this section.

[0038] A third aspect of the present disclosure provides a robotic surgical system comprising: a robotic manipulator; a surgical tool coupled to the robotic manipulator and configured to couple with a screw and rotate the screw about a rotation axis; a haptic device including an actuator and a rotation interface coupled to the actuator, the rotation interface configured to be manually operable by a hand of an operator; a navigation system configured to track a position of a target site; and one or more controllers coupled to the robotic manipulator, the haptic device, and the navigation system, wherein the one or more controllers control movement of the robotic manipulator to maintain a rotation axis of the surgical tool along a planned trajectory relative to the target site based on the tracked position of the target site; and receive control inputs from the haptic device, wherein the one or more controllers control the movement of the robotic manipulator to maintain a rotation axis of the surgical tool along a planned trajectory relative to the target site based on the tracked position of the target site. the interface is manually operable with the ability to control one of a screw rotation speed or a screw advancement speed based on an operator manually manipulating the rotary interface; and in response to control input from the haptic device, control a surgical tool to rotate the screw at a rotational speed about an axis of rotation and linearly advance the screw at an advancement speed along a planned trajectory, the rotational speed and advancement speed being predefined and proportional to a known thread form of the screw; obtain measurements indicative of a current interaction between the screw and the target site; and based on the obtained measurements, control an actuator of the haptic device to enable the rotary interface to emulate the current interaction between the screw and the target site.

[0039] A fourth aspect of the present disclosure includes a method of operating a robotic surgical system according to the third aspect of the present disclosure and, optionally, according to any embodiment in this section. The third and fourth aspects of the present disclosure are optionally implemented according to any of the embodiments in this section.

[0040] A fifth aspect of the present disclosure includes a robotic surgical system comprising: a robotic manipulator; a surgical tool coupled to the robotic manipulator and configured to rotate about a rotational axis; a haptic device including an actuator and an interface coupled to the actuator, the interface configured to be manually operable by an operator's hand; a navigation system configured to track the position of a target site; and one or more controllers coupled to the robotic manipulator, the haptic device, and the navigation system, wherein the one or more controllers are configured to: control motion of the robotic manipulator to maintain the rotational axis of the surgical tool along a planned trajectory relative to the target site based on the tracked position of the target site; autonomously control the surgical tool to rotate the surgical tool at a rotational speed about the rotational axis and to linearly advance the surgical tool at an advancement speed along the planned trajectory; obtain measurements indicative of a current interaction between the surgical tool and the target site; and, based on the obtained measurements, control the actuator of the haptic device to enable the rotational interface to emulate the current interaction between the surgical tool and the target site.

[0041] A sixth aspect of the present disclosure includes a method of operating a robotic surgical system according to the fifth aspect of the present disclosure and, optionally, according to any embodiment in this section. The fifth and sixth aspects of the present disclosure are optionally implemented according to any of the embodiments in this section.

[0042] A seventh aspect of the present disclosure includes a simulation system comprising: a haptic device including an actuator and a rotational interface coupled to the actuator, the rotational interface configured to be manually operable by an operator's hand; a display device; and one or more controllers coupled to the haptic device and the display device and configured to provide a simulation on the display device, the simulation comprising: providing a simulated surgical tool coupled to a simulated screw and configured to rotate the simulated screw about a rotational axis along a simulated trajectory relative to a simulated target site; providing simulated control of the simulated surgical tool to rotate the simulated screw at a rotational speed about the rotational axis and linearly advance the simulated screw at an advancement speed along the simulated trajectory, the rotational speed and advancement speed being predefined and proportional to a known thread profile of the simulated screw; obtaining a simulated current interaction between the simulated screw and the simulated target site; and controlling the haptic device based on the simulated current interaction to enable the rotational interface to emulate the simulated current interaction between the simulated screw and the simulated target site.

[0043] An eighth aspect of the present disclosure includes a method of operating a simulation system according to the seventh aspect of the present disclosure and, optionally, according to any embodiment in this section. The seventh and eighth aspects of the present disclosure are optionally implemented according to any of the embodiments in this section. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a perspective view of a robotic surgical system, according to one embodiment. [Figure 2]FIG. 2 is a perspective view of one embodiment of a surgical robotic arm for use with the robotic surgical system of FIG. 1. [Figure 3] FIG. 1 is a perspective view of one embodiment of a robotic surgical system used in combination with an imaging device to perform spinal surgery. [Figure 4] FIG. 1 is a partial perspective view of an example of a surgical tool coupled to a robotic arm, the surgical tool including a housing coupled to a drill. [Figure 5] FIG. 10 is a partial perspective view of a robotic arm coupled to a surgical tool coupled to a driver and a screw. [Figure 6] FIG. 10 is an elevational view of an alternative surgical tool. [Figure 7] FIG. 10 illustrates drilling a pilot hole in the pedicle according to one embodiment. [Figure 8] FIG. 1 is a diagram of a pedicle screw into a vertebra, according to one embodiment. [Figure 9] FIG. 10 is a diagram of pedicle screws placed along the line haptics. [Figure 10] FIG. 2 is a perspective view of an example of the robotic surgical system of FIG. 1, the robotic surgical system including a haptic device. [Figure 11A] 1 is a table illustrating various operating modes, including an autonomous check mode, a manual control mode, a simulated autonomous check mode, and a simulated manual control mode, and parameters of a haptic device. [Figure 11B] 10 is a table illustrating various techniques for controlling pedicle screw insertion based on input from a haptic device during manual control mode. [Figure 11C] FIG. 10 is a diagram of a rotation interface of a haptic device being manually manipulated from a home position to a non-home position. [Figure 12A] FIG. 10 is a diagram of a haptic device providing tactile feedback to the operator while the pedicle screws are being inserted during the autonomous check mode. [Figure 12B]FIG. 10 is a diagram of a haptic device providing tactile feedback to the operator while a pedicle screw is being inserted during manual control mode. [Figure 13] A and B are diagrams showing current output versus depth, which can be used to verify that drilling and pedicle screw insertion are according to the operator's plan. [Figure 14A] FIG. 1 is a perspective view of a robotic surgical system including a haptic device and displaying a simulation of a pedicle screw being inserted, according to one embodiment. [Figure 14B] FIG. 10 is a diagram of a haptic device providing haptic feedback to the operator while pedicle screws are being inserted during a simulated autonomous check mode. [Figure 14C] FIG. 10 is a diagram of a haptic device providing haptic feedback to the operator while a pedicle screw is being inserted during a simulated manual control mode. [Figure 15A] 1 is a flowchart of a method for operating a robotic surgical system using a haptic device. [Figure 15B] 10 is a flowchart of sample steps for performing an autonomous check mode. [Figure 15C] 10 is a flowchart of sample steps for implementing a manual control mode. [Figure 15D] 10 is a flowchart of sample steps for performing a simulated autonomous check mode. [Figure 15E] 10 is a flowchart of sample steps for implementing a simulated manual control mode. [Figure 15F] 1 is a flowchart of sample steps performed during a surgical procedure to autonomously control the insertion of pedicle screws PS. DETAILED DESCRIPTION OF THE INVENTION

[0045] I. System Overview 1 and 2 , a surgical robotic surgery system 10 is shown that can be used in various surgical procedures, including, but not limited to, spinal surgery, such as spinal surgery in which pedicle screws, other screws, or other types of implants are placed within the spine. The robotic surgery system 10 includes a navigation system 12 including a localizer 14 and a tracking device 16, one or more displays 18, and a robotic manipulator (e.g., a robotic arm 20 mounted to a base 22, table, or the like). The robotic arm 20 includes a base link 24 rotatably coupled to the base 22 and multiple arm links 26 extending from the base link 24 to a distal end 28. The arm links 26 pivot / rotate about multiple joints within the robotic arm 20. Surgical tools for use in performing spinal surgery are generally indicated at 30, for example. The surgical tools 30 can be pivotally coupled to the distal end 28 of the robotic arm 20. The arm links 26 can be mounted in series. Alternatively, the robotic arm 20 can include a parallel arm linkage. Additionally, any number of robotic arms 20 may be used.

[0046] The robotic controller 32 is configured to control the robotic arm 20 or provide guidance to a surgeon (referred to herein as an "operator") during manipulation of the surgical tool 30. In one example, the robotic controller 32 is configured to control the robotic arm 20 (e.g., by controlling its joint motors) to provide haptic feedback to the operator via the robotic arm 20. This haptic feedback helps the operator to constrain or inhibit manual movement of the surgical tool 30 beyond predetermined virtual boundaries associated with the surgical procedure. Such haptic feedback systems and associated haptic objects that define a virtual boundary are described, for example, in U.S. Pat. No. 8,010,180 to Quaid et al., filed February 21, 2006, and entitled "Haptic Guidance System And Method," and / or U.S. Patent Application Publication No. 2014 / 0180290 to Otto et al., filed December 21, 2012, and entitled "Systems And Methods For Haptic Control Of A Surgical Tool," each of which is incorporated herein by reference in its entirety. In one example, the robotic surgical system 10 is the RIO™ Robotic Arm Interactive Orthopedic System manufactured by MAKO Surgical Corp. of Fort Lauderdale, Florida, USA.

[0047] In some examples, the robotic arm 20 operates autonomously based on a predetermined toolpath and / or other predetermined motions to perform a surgical procedure. Such motions can be defined during and / or prior to the surgical procedure. Further examples utilize a combination of manual and autonomous control. For example, a robotic surgical system that employs both a manual mode in which an operator applies force to the surgical tool 30 to cause movement of the robotic arm 20 and a semi-autonomous mode in which the operator holds a pendant and controls the robotic arm 20 to autonomously follow a toolpath is described in U.S. Patent No. 9,566,122, filed June 4, 2015, to Bowling et al., entitled "Robotic Surgical System And Method For Transitioning Between Operating Modes," which is incorporated herein by reference in its entirety.

[0048] The navigation system 12 is set up to track the movement of various objects in the operating room with respect to a target coordinate system. Such objects include, for example, the surgical tool 30, the patient's anatomy of interest (such as one or more vertebrae), and / or other objects. The navigation system 12 tracks these objects for the purpose of displaying their relative position and orientation in the target coordinate system to the operator, and possibly for the purpose of controlling or constraining the movement of the surgical tool 30 with respect to a virtual boundary defined with respect to the target coordinate system in relation to the patient's anatomy (e.g., via coordinate system transformations well known in surgical navigation).

[0049] The surgical navigation system 12 includes a computer cart assembly 34 that houses a navigation controller 36. The navigation controller 36 and the robot controller 32 together form the control system of the robotic surgical system 10. A navigation interface is in operative communication with the navigation controller 36. The navigation interface includes a display 18 that is adjustably mounted to the computer 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 touch screen (not shown) or voice activation, are contemplated.

[0050] The localizer 14 communicates with the navigation controller 36. In the example shown, 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. Some examples use at least two optical sensors, and sometimes three or more. 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 examples, the camera unit is adjustable in at least one degree of freedom by rotating about a rotational joint. In other examples, the camera unit is adjustable in approximately two or more degrees of freedom.

[0051] The localizer 14 includes a localizer controller (not shown) 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. Alternatively, the connection can use a proprietary protocol. In another example, the light sensors communicate directly with the navigation controller 36.

[0052] The position and orientation signals and / or data are transmitted to a navigation controller 36 for purposes of tracking the object. The computer cart assembly 34, display 18, and localizer 14 may be similar to those described in U.S. Patent No. 7,725,162 to Malackowski et al., entitled "Surgery System," issued May 25, 2010, which is incorporated herein by reference in its entirety.

[0053] The robot controller 32 and the navigation controller 36, respectively or together, may include one or more personal or laptop computers and memory suitable for storing data and computer-readable instructions, such as local memory, external memory, cloud-based memory, random access memory (RAM), nonvolatile RAM (NVRAM), flash memory, or any other suitable form of memory. The robot controller 32 and the navigation controller 36, respectively or together, may include one or more processors, such as a microprocessor, that can process instructions or algorithms stored in memory and perform the functions described herein. These processors may be any type of processor, microprocessor, or multiprocessor system. Additionally or alternatively, the robot controller 32 and the navigation controller 36, respectively or together, may include one or more microcontrollers, field programmable gate arrays, systems-on-chips, discrete circuits, and / or other suitable hardware, software, or firmware capable of performing the functions described herein. The robot controller 32 and the navigation controller 36 may be carried by the robot manipulator or computer cart assembly 34 and / or mounted in any other suitable location. The robot controller 32 and / or navigation controller 36 are loaded with software, as described below, that converts signals received from the localizer 14 into data representing the position and orientation of the object being tracked.

[0054] In addition to the robot controller 32, the surgical robotic system 10 may include any number of controllers for controlling components of the surgical robotic system 10. For example, the surgical robotic system 10 may include a tool controller configured to control the surgical tool 30. As another example, the surgical robotic system 10 may include a haptic device controller configured to control a haptic device of the surgical robotic system 10 (described in more detail below). The controllers of the surgical robotic system 10 may be configured to perform surgical functions individually or in combination. For example, the robot controller 32, the navigation controller 36, the localizer controller, the tool controller, and the haptic device controller may operate in combination to provide haptic feedback to the operator via the haptic device of the surgical robotic system 10. As another example, the robot controller 32 may operate individually to control the robotic arm 20. Accordingly, to capture these various configurations, the following description may refer to “one or more controllers 33,” as also shown in FIG. 1 . It should be understood that “one or more controllers 33” includes any individual controller or any combination of controllers suitable for performing the referenced functions. Collectively, one or more controllers can also be considered a control system.

[0055] Additionally, any of the steps herein performed by any of the one or more controllers 33 described herein may operate according to a control algorithm described herein, which may be implemented according to a finite series of steps to solve a task described herein.

[0056] Referring to FIG. 3 , the navigation system 12 includes multiple tracking devices 16, also referred to herein as trackers. In the illustrated example, the trackers 16 are coupled to separate vertebrae of the patient. In some cases, the trackers 16 are secured to sections of bone via bone screws, bone pins, or the like. In other cases, the trackers 16 can be attached using clamps over the spinous processes or other portions of the spine. In further examples, the trackers 16 can be attached to other tissue types or portions of the anatomy. 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, in which a digital probe 73 (e.g., a navigation pointer with its own marker) is used to turn contact off on a bone landmark on the bone, or to turn contact on at several 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, such as the vertebra V being treated.

[0057] Other types of registration are also possible, such as using a tracker 16 with a mechanical clamp that attaches to the spinous process of a vertebra V and includes tactile sensors (not shown) that determine the shape of the spinous process to which the clamp is attached. The shape of the spinous process can then be matched to a 3D model of the spinous process for registration. Known relationships between the tactile sensors and three or more markers on the tracking device 16 are preloaded into the navigation controller 36. Based on these known relationships, the positions of the markers relative to the patient's anatomy can be determined.

[0058] The base tracker 16 may be coupled to the base 22 to track the orientation of the surgical tool 30. In other examples, a separate tracker 16 may be affixed to the surgical tool 30, such as integrated into the surgical tool 30 during manufacturing, or separately attached to the surgical tool 30 in preparation for a surgical procedure. In either case, the working end of the surgical tool 30 is tracked by the base tracker 16 or another tracker. The working end can be the distal end of an accessory to the surgical tool 30. Such accessories can include drills, burrs, saws, an electrical ablation device, a screwdriver, a tap, a surgical knife, a Jamshidi needle, or the like.

[0059] In the illustrated example, the trackers 16 are passive trackers. In this example, each tracker 16 includes at least three passive tracking elements or markers M to reflect light from the localizer 14 back to an optical sensor. In other examples, the trackers 16 may be active trackers and include light-emitting diodes or LEDs that transmit light, such as infrared light, to an optical sensor. Based on the received optical signals, the navigation controller 36 generates data indicating the relative position and orientation of the tracker 16 with respect to the localizer 14 using conventional triangulation techniques. 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, ultrasound, radio frequency tracking, inertial tracking, or combinations thereof, may alternatively or additionally be utilized to track the object.

[0060] It may also be desirable to track the patient's skin surface to ensure that the surgical tool 30 does not inadvertently contact or penetrate the patient's skin outside any desired incision boundaries. To this end, skin-adherent markers M, such as active or passive markers with adhesive backings, can be attached to the patient's skin to define the boundaries associated with the patient's skin. An array of such markers M can be provided on the peripheral ring 74 (circular, rectangular, etc.) without substantially obstructing the ring 74, such that the surgical procedure continues inside the ring 74 (i.e., the ring is placed on the patient's skin around the intended incision and vertebrae). One suitable skin marker array is the SpineMask® Tracker, manufactured by Stryker Leibinger GmbH & Co. KG (Botzinger StraBe41, D-79111 Freiburg, Germany). See also U.S. Patent Application Publication No. 2015 / 0327948 to Schoepp et al., filed May 13, 2015, entitled "Navigation System For And Method Of Tracking The Position Of A Work Target," which is incorporated herein by reference in its entirety. Other suitable skin trackers are contemplated. Digital probes can also be used to map the skin surface and / or incisions. However, once mapped, they do not detect any movement of the skin without further digitization, whereas an attached tracker array can detect movement of the patient's skin.

[0061] Prior to the start of a surgical procedure, additional data is loaded into the navigation controller 36. Based on the position and orientation of the tracker 16 and the previously loaded data, the navigation controller 36 determines the position of the working end of the surgical tool 30 and the orientation of the surgical tool 30 relative to the tissue to which the working end will be applied. The additional data may include calibration data, such as geometric data regarding the position and / or orientation of the tracker 16 or its markers M relative to the working end of the surgical tool 30. This calibration data may also be determined preoperatively or intraoperatively, such as by using a calibration probe or calibration divot on the tracker 16 of known geometry to determine the position of the working end of the surgical tool 30 relative to its own tracker or a base tracker 16. The additional data may include registration data, such as transformation data relating the tracker 16 to the patient's anatomy or a 3D model thereof. In some examples, the navigation controller 36 transfers this data to the robot controller 32. The robot controller 32 can then use this data to control the robot arm 20 as described in U.S. Pat. Nos. 8,010,180 or 9,566,122, both of which are incorporated herein by reference in their entireties.

[0062] The navigation controller 36 also generates image signals indicative of the relative position of the working end of the surgical tool 30 with respect to the tissue of interest. These image signals are applied to the display 18. Based on these signals, the display 18 generates an image that allows the operator and staff to view the relative position of the surgical tool 30 with respect to the surgical site. The display 18, as discussed above, may include a touch screen or other input / output device that allows commands to be entered.

[0063] In the illustrated example, the pose of the surgical tool 30 can be determined by using the navigation system 12 to track the position of the base 22 via the base tracker 16 and calculate the pose of the surgical tool 30 based on joint encoder data from the joints of the robotic arm 20 and the known geometric relationship between the surgical tool 30 and the robotic arm 20. Ultimately, the localizer 14 and tracking device 16 enable the pose of the surgical tool 30 and the patient's anatomy to be determined, so that the navigation system 12 knows the relative relationship between the surgical tool 30 and the patient's anatomy. One such navigation system is shown in U.S. Patent No. 9,008,757 to Wu, filed September 24, 2013, and entitled "Navigation System Including Optical And Non-Optical Sensors," which is incorporated herein by reference in its entirety.

[0064] During surgery, for a particular surgical task, the operator manually manipulates the robotic arm 20 (e.g., moves or causes movement of the robotic arm) and manipulates the surgical tool 30 to perform a surgical operation on the patient, such as drilling, cutting, sawing, reaming, implant insertion, etc. As the operator manipulates the surgical tool 30, the navigation system 12 tracks the position of the surgical tool 30 and / or the robotic arm 20, provides haptic feedback (e.g., force feedback) to the operator, and limits the operator's ability to move (or cause movement of) the surgical tool 30 beyond one or more predetermined virtual boundaries registered (or mapped) to the patient's anatomy, resulting in highly accurate and repeatable drilling, cutting, sawing, reaming, and / or implant placement.

[0065] In one example, the robotic arm 20 operates in a passive manner, providing haptic feedback when the operator attempts to move the surgical tool 30 beyond a virtual boundary. The haptic feedback is generated by one or more actuators (e.g., joint motors) within the robotic arm 20 and transmitted to the operator via a flexible transmission, such as a cable-driven transmission. When the robotic arm 20 is not providing haptic feedback, the operator can freely move the robotic arm 20. In another example, similar to that shown in U.S. Pat. No. 9,566,122, which is incorporated herein by reference in its entirety, the robotic arm 20 is manipulated by the operator in a similar manner, but operates in an active manner. For example, when the operator applies force to the surgical tool 30, a force / torque sensor measures the force, and the robotic arm 20 emulates the operator's desired movement based on the measurements from the force / torque sensor. For other surgical tasks, the robotic arm 20 operates autonomously.

[0066] 4 and 5, an example of a surgical tool 30 coupled to the distal end 28 of the robotic arm 20 is shown. More specifically, a coupling 40 is provided between the surgical tool 30 and the distal end 28 of the robotic arm 20, allowing rotation of the surgical tool 30 relative to the distal end 28 about axis A. In FIG. 4, the surgical tool 30 includes a drill 42 for drilling pilot holes for pedicle screws, other screws, or other types of implants. The drill 42 is positioned to rotate about an axis of rotation R. In FIG. 5, the surgical tool 30 includes a driver 44 (e.g., a screwdriver) positioned along the axis of rotation R for rotation about the axis of rotation R to insert a pedicle screw PS or other implant. The surgical tool 30 includes a housing 45. A drive system (e.g., a motor) is located within the housing 45 for driving the drill 42, the driver 44, or another accessory. The drive system may be variable speed.

[0067] Additionally, the housing 45 includes a collet 47 or other type of coupler for releasably attaching the drill 42, driver 44, or other accessory to the driveline. Optionally, a reducer 48 (see FIG. 5) may be releasably attached to the collet 47 and used with certain accessories. The reducer 48 includes a transmission or gear arrangement that reduces the rotational speed of the accessory compared to if it were directly coupled to the driveline. This is useful when a slower rotational speed is desired.

[0068] In another example shown in FIG. 6 , one end of coupling 40 supports surgical tool 30 for rotation about axis A. The other end of coupling 40 supports housing 45. Housing 45 may be fixed to coupling 40 or may be supported within coupling 40 for rotation about rotation axis R. In other words, housing 45 can passively rotate within coupling 40. At the same time, however, coupling 40 limits axial movement of housing 45 along rotation axis R relative to coupling 40 so that positioning of housing 45 can be precisely controlled. A tracker (not shown) can be attached to housing 45 to track the position and / or orientation of housing 45, thereby tracking rotation axis R and / or the distal end of an accessory attached to housing 45. Rotational shaft 60 is rotatably supported within housing 45. Rotation shaft 60 includes a distal interface / collet 62 that couples to an accessory (e.g., driver 44 as shown) and a proximal interface / collet 64 that couples to a power source, such as a torque source such as a motor, a rotatable handle for manual rotation, etc. For example, driver 44 is shown coupled to distal interface 62 / rotation shaft 60.

[0069] The robotic surgical system 10 may include various components for controlling the drill 42 and / or driver 44. For example, in FIGS. 4 and 5 , the surgical tool 30 includes a handle 46 depending from a housing 45. The handle 46 may include a grip that an operator grasps to manipulate the surgical tool 30 and / or the robotic arm 20 during a surgical procedure. A trigger 49 is also present, which controls the speed of the drill 42 and / or driver 44, initiates movement of the robotic arm 20, aligns the axis of rotation R with a desired trajectory, etc. The trigger 49 can communicate signals to the robot controller 32 and / or tool controller to control the robotic arm 20 and / or the surgical tool 30.

[0070] 6, the surgical tool 30 includes a handpiece 66 with an internal motor for controlling the surgical tool 30 and the drill 42. As shown, the handpiece 66 is coupled to the proximal interface 64 such that an operator can grasp the handpiece 66 and trigger operation of the motor, causing the motor to transmit torque via the rotating shaft 60 to the driver 44 and ultimately to the pedicle screw PS.

[0071] Preoperative and / or intraoperative imaging can be used to visualize the patient's anatomy requiring treatment, such as the patient's spine. The operator can plan the placement of the pedicle screws PS with respect to the images and / or with respect to a 3D model created from these images. This planning can include determining the orientation of each pedicle screw PS relative to the particular vertebra V in which it is to be placed, for example, by identifying the desired orientation within the images and / or 3D model. This can include creating or positioning separate 3D models of the pedicle screws PS with respect to the 3D model of the patient's anatomy. Once the plan is established, it can be transferred to the robotic surgical system 10 for execution.

[0072] The robotic surgery system 10 can be used with an imaging device 50 (e.g., a C-arm shown in FIG. 3 ) to obtain intraoperative images of the patient's anatomy in addition to, or in place of, any preoperative images, such as X-rays, CT scans, or MRI images obtained before surgery. The intraoperative images from the imaging device 50 can help determine the actual position of the drill 42 or driver 44 relative to the desired orientation of the pedicle screws PS being placed in the patient's spine. A separate tracking device 16 can be used for each vertebra V to separately track each vertebra V and the corresponding orientation of the drill 42 and / or driver 44 relative to the individual vertebra V as the pedicle screws PS or other implants are placed into the vertebra V.

[0073] The robotic surgical stem 10 assesses the desired orientation of the pedicle screw PS, creates a virtual boundary (e.g., a haptic object), a predefined tool path, and / or other autonomous motion commands corresponding to the desired orientation of the pedicle screw PS, and controls the movement of the robotic arm 20, and the drill 42 and driver 44 of the surgical tool 30, to ultimately place the pedicle screw PS according to the operator's plan. This may include, for example, ensuring that the trajectory of the surgical tool 30 is aligned with the desired orientation of the pedicle screw PS during the surgical procedure, e.g., that the axis of rotation R is aligned with the desired orientation of the pedicle screw PS.

[0074] In other examples, the operator may plan a desired trajectory and / or screw placement during surgery. For example, the operator may position the drill 42 at a desired insertion point relative to the target anatomy, e.g., vertebra V, and orient the drill 42 until the display 18 indicates that the trajectory of the rotation axis R is within the desired orientation. Once the operator is satisfied with this trajectory, the operator may provide an input (e.g., a touchscreen, button, foot pedal, etc.) to the control system that sets this trajectory as the desired trajectory to be maintained during surgery. A haptic object created to constrain the movement of the surgical tool 30 to maintain the rotation axis R and stay along the desired trajectory may be a line haptic object LH, as shown in FIG. 4. The line haptic object LH may include a start point SP, a target point TP that defines the desired depth of the drill 42, pedicle screw PS, etc., and an insertion point EP, as described further below. Other haptic object shapes, sizes, etc. are also contemplated.

[0075] 7 and 8, one of the vertebrae V is shown. During a surgical procedure, such as a spinal fusion procedure, an operator can insert one or more pedicle screws PS through the pedicle region into a vertebral body 100 of the vertebra V. Prior to inserting the pedicle screws PS, the operator can drill a pilot hole 102 in the vertebral body 100 using a drill 42. In an alternative example, the pilot hole can be omitted, such as when using a self-drilling, self-tapping bone screw. See, for example, the teachings of U.S. Patent No. 7,637,929, issued December 29, 2009, to Stefan Auth, entitled "Self-drilling bone screw," which is incorporated herein by reference in its entirety.

[0076] In one example, before drilling begins, the robotic surgical system 10 autonomously aligns the rotation axis R of the surgical tool 30 with a desired trajectory that coincides with the desired orientation of the pilot hole 102, thereby controlling the movement of the surgical tool 30 to place the rotation axis R along the desired trajectory. In this case, the robotic arm 20 can autonomously position the drill 42 along the desired trajectory but spaced above the vertebral body 100 (as shown in FIG. 4 ), with the drill 42 not yet in contact with the vertebral body 100. Such autonomous positioning can be initiated by an operator pulling the trigger of the surgical tool 30 or otherwise providing an input to the control system that initiates the movement. In some cases, the tool center point (TCP) of the surgical tool 30 is initially brought within a predetermined distance (e.g., within a predetermined starting sphere) of the starting point SP of the line haptic object LH that provides the desired trajectory. Once the TCP (e.g., the center of gravity of a burr, the center of a drill tip, etc.) is within a predetermined distance from the starting point SP, pulling a trigger (or alternatively pressing a foot pedal or moving another input) causes the robotic arm 20 to autonomously align and position the surgical tool 30 on the desired trajectory. See, for example, U.S. Patent Application Publication No. 2014 / 0180290 to Otto et al., filed December 21, 2012, and entitled "Systems And Methods For Haptic Control Of A Surgical Tool," which is incorporated herein by reference in its entirety. The robotic arm 20 can be programmed to move the surgical tool 30 a fixed distance from the patient based on a preoperative plan, or it can move the TCP to the nearest point on the trajectory. Once the surgical tool 30 is in the desired pose, the robotic surgical system 10 can effectively maintain the rotation axis R of the surgical tool 30 on the desired trajectory by tracking the patient's movements and autonomously adjusting the robotic arm 20 as needed to keep the rotation axis R on the desired trajectory, i.e., in alignment with the line haptic object LH.

[0077] While the robotic surgical system 10 holds the surgical tool 30 on the desired trajectory, the operator can manually manipulate the surgical tool 30 to move (or cause movement of) the drill 42 along the line haptic object LH toward the vertebral body 100 to drill the pilot hole 102. In some cases, such as when using a passive robotic arm 20, if the operator attempts to move the surgical tool 30 in a manner that deviates from the line haptic object LH and the desired trajectory, the robotic surgical system 10 provides haptic feedback to the operator to constrain the operator's movement of the surgical tool 30 to stay along the desired trajectory. If the operator wishes to return the robotic arm 20 to free mode due to unconstrained movement of the surgical tool 30, the operator can pull the surgical tool 30 back along the line haptic object LH and away from the patient until the insertion point EP is reached.

[0078] The operator then drills the pilot hole 102 to the desired depth. The drilling speed can be controlled by the operator via the trigger 49 or can be automatically controlled based on the position of the drill 42 relative to the patient's anatomy. For example, the rotational speed of the drill 42 can be set high during initial drilling into the vertebral body V, slowed during further drilling into the vertebral body V, and set even slower during final drilling to the final depth. The control system can also monitor contact / contact force during line haptic guidance via one or more sensors S (e.g., one or more force sensors, force / torque sensors, torque sensors, pressure sensors, optical sensors, etc.) in communication with the robot controller 32. If significant contact / contact force is not detected, meaning the surgical tool 30 is passing through soft tissue, the control system will not activate the motor or other power source (e.g., RF energy, ultrasonic motor, etc.) of the surgical tool 30. If contact with bone is detected (e.g., if an optically sensed force exceeds a predetermined threshold), the control system can activate the motor or other power source. Also, the operator can passively feel the contact / contact force and trigger the switch to activate the power source.

[0079] When the operator reaches the desired depth of the pilot hole 102, e.g., when the target point TP is reached, a virtual boundary (e.g., a haptic object) used to constrain the operator's movement along the desired trajectory may also be indicated via haptic feedback. A separate virtual boundary may also be used to set the desired depth. In other cases, the robotic surgical system 10 may autonomously drill the pilot hole 102 to the desired depth. In further cases, the robotic surgical system 10 may initially drill autonomously, but then manually perform the final drilling, or vice versa. Once the pilot hole 102 is created, the driver 44 may be used to place the pedicle screw PS. In some instances, the pilot hole 102 may not be necessary, and the pedicle screw PS may be placed over a guidewire placed by the robotic surgical system 10 or without any guidance. A pilot hole may not be necessary, such as when using self-drilling, self-tapping bone screws. See, for example, the teachings of U.S. Patent No. 7,637,929 to Stefan Auth, entitled "Self-drilling bone screw," issued December 29, 2009, which is incorporated herein by reference in its entirety.

[0080] One advantage of using the navigation system 12 to continuously track each vertebra V separately and track the movement of the drill 42 is that the pedicle screws PS can be inserted in close proximity to the spinal cord 103; therefore, the placement of the pedicle screws PS and their corresponding pilot holes 102 must be precisely aligned to avoid interaction with or damage to the spinal cord 103. If the operator drills the pilot holes 102 at an improper angle and / or too deep, the pedicle screws PS, or the drill 42 used to drill the pilot holes 102, can damage the spinal cord 103. As a result, the spinal cord 103 can be avoided by using the navigation system 12 to track the orientation of the drill 42 and / or driver 44 relative to the patient's anatomy, specifically the anatomy as outlined in the preoperative and / or intraoperative images.

[0081] Once drilling is complete, the drill 42 is removed from the vertebral body 100 and disconnected from the drive system via the collet 47. The driver 44 (with or without the reducer 48) is then coupled to the drive system.

[0082] The pedicle screws PS can be inserted with the aid of the robotic surgical system 10. In one example, the robot controller 32 autonomously controls the insertion of the pedicle screws PS such that the rotational speed about the rotation axis R and the advancement speed along the planned trajectory are proportional to the thread form of the pedicle screws. The robot controller 32 can autonomously control the insertion of the pedicle screws PS using a variety of methods.

[0083] For example, the pedicle screws PS may be inserted at a constant rotational speed or a constant advancement speed, which may be stored preoperatively in the memory of the robotic surgical system 10. In such cases, the advancement speed and / or rotational speed may be stored in the memory of the robotic surgical system 10 prior to surgery. The advancement speed and / or rotational speed may also be entered and stored in the memory of the robotic surgical system during surgery by the operator.

[0084] In another example, the robotic controller 32 can follow a predetermined profile for rotational or advancement speed. The predetermined profile for rotational or advancement speed can be based on any suitable variable, such as time or the position of the pedicle screw PS. For example, with reference to FIG. 9 , insertion of the pedicle screw PS can be autonomously controlled based on the position of the driver 44 and / or the pedicle screw PS relative to the patient's anatomy. In such a case, the rotational speed of the driver 44 can be set high during initial insertion into the vertebral body V, slowed during further insertion into the vertebral body V, and set even slower during final implantation to the final depth.

[0085] FIG. 9 illustrates the home position of the pedicle screw PS while the robotic controller 32 autonomously controls the surgical tool 30. As shown, the pedicle screw PS is adjacent to the target site, in this case, shown as vertebra V, with a planned trajectory specified by the linear haptic object LH. The threaded interface between the pedicle screw PS and the vertebral body 100 poses a risk of damage to the bone, the screw PS, the driver 44, or the surgical tool 30 if the pedicle screw is not inserted correctly. Because bone is perhaps the weakest material, it is most likely to be damaged if the screw is not inserted correctly. Improper insertion can occur, for example, when the pedicle screw PS advances linearly along the trajectory LH with insufficient rotation about the rotation axis R. This can cause bone material to shear adjacent to the threads and become wedged into the bone. In another example, improper insertion can occur when, for example, the pedicle screw PS rotates about the axis of rotation R with insufficient advancement along the trajectory LH, causing bone material to shear adjacent to the threads and be forced back along the threads, effectively over-drilling the hole. In either example, the result of improper insertion is a decrease in the strength and amount of bone material securing the pedicle screw PS to the bone.

[0086] FIG. 9 also illustrates the use of position control to insert the pedicle screw PS while the robotic controller 32 autonomously controls the surgical tool 30. Position control for inserting the screw ensures that the proper depth and angular or rotational position are maintained throughout the procedure. As shown in the example above, a pilot hole can be formed in the vertebral body 100, or the procedure can use self-drilling and self-tapping screws that do not require a pilot hole. The starting point Do of the pedicle screw PS is adjacent to the vertebral body 100, i.e., before any portion of the screw penetrates the vertebral body 100. In an alternative example, the starting point Do can be spaced a certain distance from the vertebral body 100 as a safety margin to ensure proper position control throughout the procedure. The insertion depth D is the planned depth to complete the insertion of the pedicle screw PS into the vertebral body 100, proceeding along the trajectory LH to a final depth Df.

[0087] The robot controller 32 is configured to autonomously control the insertion of the pedicle screws PS such that the rotational speed and the advancement speed along the trajectory LH are proportional to the thread profile of the pedicle screws PS. Each pedicle screw PS has a known thread profile stored in the memory of the robotic surgical system 10. For example, for each pedicle screw PS, the thread profile may include any one or more of the length of the pedicle screw PS, the thread diameter, the thread depth, the head size, and the thread pitch P, which is defined as the number of threads per unit length. In a specific example, the pedicle screw PS shown in FIG. 11A can have a thread pitch of 12 threads per inch (2.54 centimeters). Other exemplary pedicle screws PS can have 8, 10, 14, 16, or other numbers of threads per inch (2.54 centimeters). By having a defined relationship between the robotic arm 20 and the pedicle screw PS and the known geometry of the pedicle screw PS stored in the memory of the robotic surgical system 10, the robotic controller 32 is configured to ensure the proper rotational and advancement speeds for inserting a pedicle screw PS having a particular thread pitch.

[0088] The thread forms of the pedicle screws PS can be stored in the memory of the robotic surgical system 10 preoperatively or intraoperatively. In one example, the pedicle screws PS are selected as part of a surgical plan, and the corresponding thread forms of the pedicle screws PS are associated with the pedicle screws PS and entered into the plan. When the plan is loaded for intraoperative surgery, the robotic surgical system 10 stores the known thread forms in memory for immediate access. In another example, the operator can manually select a different pedicle screw PS or manually input the thread form using a GUI associated with operation of the robotic surgical system 10. The input thread form can be retrieved from a database stored in memory, or the operator can derive such information from an offline specification associated with the selected pedicle screw PS. In either of these examples, the thread form can be stored in memory after being input by the operator using the GUI, and the robotic surgical system 10 can then execute the control techniques described herein using the input thread form. In yet another example, a measurement tool connected directly or wirelessly to the robotic surgical system 10 can be utilized to scan or measure any intended pedicle screws PS, extract the thread form, and transmit the measured thread form to the memory of the robotic surgical system 10. Once the thread form of the pedicle screws PS is stored in the memory of the robotic surgical system 10, the pedicle screws PS can be virtually presented within the navigation system 12.

[0089] The relationship between the pitch, angular or rotational position of the pedicle screw threads and the insertion depth or advancement along the trajectory is determined by the equation θ=D*(pitch / 2π), where θ is the angular position, D is the insertion depth per unit length, and pitch is the number of threads per unit length of the pedicle screw PS. The robot controller 32 uses this relationship to control the insertion of the pedicle screw PS. For example, taking the first derivative with respect to time, the rate of change in angular position, or rotational speed δθ / δt, is equal to the rate of change in insertion depth, or advancement speed δD / δt, multiplied by the pitch divided by 2π. This can be expressed as follows: δθ / δt=δD / δt*pitch / 2π (Equation 1).

[0090] The robotic surgical system 10 may include various accessories for preparing the anatomy for the pedicle screws PS. For example, one of the accessories of the surgical tool 30 may include a skin incision tool, such as a scalpel, electrocautery, or other tool with a sharp tip. The skin incision tool may be attached similarly to the drill 42 and / or driver 44, or may be part of a separate end effector and connected to a mount that attaches to the coupling 40. The skin incision may be performed using haptic guidance in a manner similar to that described above, i.e., virtual boundaries (e.g., haptic objects), which can be used to constrain the operator's movement relative to the desired incision in the patient's skin when creating the incision. In one example, a digital probe may be used to contact the desired incision location and create the associated boundaries / haptic objects. In another example, a 3D skin model may be determined based on the pose of a skin tracker by digitization and / or preoperative methods, and the control system may use the desired plan for pedicle screw placement to determine the location of the incision based on this skin model.

[0091] Other types of pointers similar to digital probes can also be used to identify the desired incision location, such as a laser pointer, end effector, or other component that can be attached to a skin incision tool and project visible light onto the patient's skin to indicate the location of the incision. Such a laser pointer can be used to first align the desired trajectory with the skin incision tool's rotation axis R, and then activate the laser pointer to project light along the desired trajectory. Alternative forms of skin incision tools are positioned through tool guides held in place by a robotic arm. For tracking of the patient's skin achieved via a skin tracker, the navigation system 12 can also approximately determine the desired location of the incision based on a skin model (e.g., a surface model or point cloud) and the intersection of the desired trajectory with the skin model, allowing the operator to make the desired incision at the desired location within the patient's skin via tactile feedback.

[0092] The haptic object can be defined in various ways to establish haptic feedback to guide the dissection procedure. The haptic object can be defined based on the width of the skin incision tool, the desired length of the skin incision, and / or the desired depth of the incision. The desired incision depth can also be controlled by the operator up to a maximum incision depth, which can be determined either by this maximum incision depth being programmed as part of the haptic object or by a mechanical stop that can be used to prevent the skin incision tool from sliding beyond a predetermined point into a guide opening (not shown) in the tool guide TG of the end effector.

[0093] One of the accessories of the surgical tool 30 may include a wire insertion tool, such as a Jamshidi needle or another access cannula with a stylet. The wire insertion tool can be attached similarly to the skin incision tool, or it can be part of a separate end effector and fixedly coupled to a mount attached to the coupling 40. If relative movement between the wire insertion tool and the mount is not permitted, i.e., they are fixed to each other, the wire insertion tool can be guided by the line haptic object to enter the skin incision and reach the target point on the bone, e.g., a vertebra. If relative axial sliding movement between the wire insertion tool and the mount is permitted, such as when the mount includes a tool guide with an opening, the tool guide can be positioned in a desired orientation, and the wire insertion tool can be inserted along the opening in the tool guide. Depending on the relative distance to the target point, the length of the wire insertion tool, and the tool guide position, the wire insertion tool can be guided via the line haptic object in the same manner as described above for the drill 42 and / or driver 44.

[0094] Because the skin and the desired location for the incision are tracked, the robotic surgical system 10 can control the movement of a skin incision tool relative to a haptic object created for the incision. The haptic object is defined in a target coordinate system to incise the desired location within the patient's skin. In one example, the robotic surgical system 10 can control the movement of the skin incision tool relative to the haptic object by controlling manual manipulation of the skin incision tool. This can be done by constraining the movement of the skin incision tool relative to a virtual boundary defined by the haptic object so that the skin incision tool makes the incision at the desired location while the operator manually moves it or while the operator manually triggers the movement of the skin incision tool. The robotic surgical system 10 can constrain the movement of the skin incision tool relative to the haptic object by generating haptic feedback to the operator indicating that the skin incision tool has reached the desired depth of the incision or otherwise reached a desired limit for the incision. Once the incision is made at the desired location, the skin incision tool is withdrawn from the anatomy, and the surgery proceeds until all incisions have been made. The skin incision technique may be similar to that described in U.S. Patent Application No. 16 / 184,376, filed November 8, 2018, entitled "Robotic Spine Surgery System and Methods."

[0095] II. Haptic Feedback Technology As described above, the robotic system 10 can be utilized to control the surgical tool 30 to rotate a screw along a planned trajectory. Described herein are technologies utilized in conjunction with the robotic system 10 to provide the surgeon with direct tactile "feel," contact or control of the forces, energy, material, and information flows involved while the robotic system 10 interacts with the surgical tool 30. The technology described herein then provides a technological solution for emulating the tactile and sensory information that surgeons are accustomed to (manually) for monitoring and evaluating tissue interaction processes during a surgical procedure. The haptic technology described herein restores the surgeon's ability to evaluate processes during robotically controlled surgery. This solution provides a sophisticated mechanism for providing tactile feedback, for example, using one degree of freedom (e.g., rotation) and one concomitant phenomenon (e.g., resistance). The haptic device may include an interface (e.g., knob) that controls or emulates the interaction of a screw (or accessory) manipulated by the robotic arm 20 and / or surgical tool 30. In some examples, the resistance of the interface can be modulated or amplified, dynamically changing depending on the interaction between the screw and the surrounding tissue into which it is inserted. In some examples, the user manipulates the interface, causing the robot to rotate and advance the screw. The robotic system captures parameters of the screw insertion process via appropriate sensors. The sensor information is then translated and used to modulate feedback to the interface, thereby providing the surgeon with enhanced sensory acuity that helps them understand the consistency of the tissue into which the screw is being inserted and the quality of the form's grip that fits between the screw and the tissue. In turn, the haptic technology described here increases surgeon confidence, reduces emotional stress, increases procedural effectiveness, and provides the surgeon with the ability to recognize and respond to unexpected situations not captured by robotic solutions.

[0096] The haptic technology described herein can be used in a variety of medical applications. For example, while the haptic technology is associated with screw insertion processes, the haptic technology can also be used in a variety of other medical applications. As one example, during a procedure involving a scalpel or syringe, the haptic device interface can provide haptic feedback to emulate the force applied by the scalpel or syringe as it advances through different tissues. The haptic technology can be used in procedures involving soft tissue to prevent damage to the soft tissue. For example, during a procedure in which a distractor separates soft tissue, the haptic device interface can provide haptic feedback to emulate the force applied by the distractor to the soft tissue (or the tension applied by the soft tissue on the distractor) as the distractor separates soft tissue at a wound site, a surgical opening, between bones in a joint cavity, or between bones during bone growth procedures (e.g., mandibular distraction). As another example, during a procedure involving a tourniquet, the haptic device interface can provide haptic feedback to emulate the pressure applied to the soft tissue by the tourniquet. As yet another example, during surgery involving a jack to open a joint space, the haptic device interface may provide haptic feedback to emulate the force applied to the ligaments by the jack (or tension due to the ligaments on the jack) to aid in the process of balancing the ligaments.

[0097] A. Haptic Devices Referring to one example, as shown in FIG. 10 , the robotic surgical system 10 includes a haptic device 51 for controlling the surgical tool 30. The haptic device 51 may include an interface 53 that may be manually operable by the operator's hand. In one non-limiting example, the haptic device 51 may be a handheld pendant. Alternatively, the haptic device 51 may include a unit that can be placed on a surface, a haptic glove, or a physical design that mimics a tool utilized in manual surgery (e.g., a screwdriver). The haptic device 51 may be any other device configured to provide the surgeon with the functionality described herein.

[0098] The term "device" in haptic device is not limited to the specific embodiment(s) described herein. Indeed, a haptic device may include any device configured to provide an operator with a haptic sensation (feel) that emulates conditions in an environment remote from the haptic device. The device may be comprised of one or more of mechanical, electrical, electromechanical, software, controller(s), pneumatic, and / or hydraulic components to provide the appropriate haptic sensation.

[0099] In FIG. 10 , the haptic device 51 is attached directly to the robotic manipulator or surgical tool 30 via the base 22. In other examples, the haptic device 51 may be attached to any other suitable component of the robotic surgical system 10, such as the computer cart assembly 34 or the navigation system 12. In yet another example, the haptic device 51 may be directly coupled to the robotic arm 20 or the surgical tool 30 such that the haptic device 51 does not need to be held by the operator. The haptic device 51 may also be remotely located, spaced apart from the robotic manipulator and surgical tool 30, as shown in FIG. 10 . In such cases, the haptic device 51 may be wirelessly coupled to the robotic surgical system 10. Alternatively, the haptic device 51 may be powered by a cord connected to the system 10, as shown in FIG. 10 . In yet other examples, the haptic device 51 may be used as a standalone device that is not necessarily attached to the robotic surgical system 10. For example, the haptic device 51 may be used with a surgical system that does not include a robotic manipulator and / or a navigation system 12.

[0100] The interface 53 of the haptic device 51 can move with a degree of freedom relative to the haptic device 51. In one example, the interface 53 is a rotary interface that can move with a rotational degree of freedom relative to the haptic device 51. In some examples, the rotary interface 53 can be a rotary knob, as shown in FIG. 10 . The rotary interface 53 can also be a rotatable dial, ball, or wheel. The interface 53 can have a configuration other than that specifically shown in the drawings or described herein.

[0101] The rotational interface 53 may be desirable to allow the operator to associate the rotational degree of freedom of the rotational interface 53 with the rotational degree of freedom about which the screw or tool rotates. However, configurations other than the rotational interface 53 can be utilized to implement the interface 53 of the haptic device 51. For example, the haptic device 51 may include a linear interface 53 that may be manually operable by the operator's hand. In some examples, the linear interface 53 may be a pivot lever, a push button, a palm or finger trigger, a spring switch, a plunger, an elastic pad, or a slider. Additionally, the one or more controllers 33 may control the actuator 55 of the haptic device 51 to enable the linear interface 53 to emulate the current interaction between the screw and the target site. For example, if the linear interface 53 is a push button, the one or more controllers 33 may control the actuator 55 to cause the operator to apply more or less force to press the push button depending on the current interaction. In another example, if the linear interface 53 is a switch or plunger, the one or more controllers 33 can control the actuator 55 of the haptic device 51 so that the operator applies a greater or lesser force to actuate the switch or plunger. In yet another example, the linear interface 53 is a slider that includes a mechanism configured to slide along a path. The one or more controllers 33 can control the actuator 55 of the haptic device 51 so that the operator applies a greater or lesser force to actuate the slider and / or control the actuator 55 to limit the linear displacement of the slider.

[0102] The robotic surgical system 10 provides haptic feedback to the operator via the haptic device 51. As shown in FIG. 10 , the haptic device 51 may include an actuator 55 that can be controlled by one or more controllers 33. The actuator 55 is coupled to the interface 53 and configured to apply a force to the interface 53. The actuator 55 may include a drive output drive shaft 68 coupled between the actuator 55 and the interface 53. The one or more controllers 33 can control the actuator 55 to enable the interface 53 to emulate the current interaction between the screw and the target site. In some examples, the interface 53 is utilized to directly control the surgical tool 30 and / or the driver 44 to rotate the screw. Direct control via the haptic device 51 can also be combined with haptic feedback to emulate the current interaction between the screw and the target site. In these examples, the operator can perceptually associate the degrees of freedom of the interface 53 with the degrees of freedom about which the screw moves.

[0103] The actuator 55 may be implemented as a motor such as a brushed or brushless motor, a direct drive motor, an active actuator, a DC motor, an electric linear motor, a linear current controlled motor, a stepper motor, an electric rotary motor, a torquer (a motor with a limited angular range), a spring-based actuator, a magnetic actuator, a hydraulic actuator, a pneumatic actuator, a manual mechanical actuator, a passive actuator including a magnetic particle brake, a friction brake, a damped resistance mechanism, or a friction generating mechanism, or a combination thereof.

[0104] In some examples, the haptic device 51 may include safety features to prevent unintended use of the robotic system 10 or the haptic device 51. For example, the haptic device 51 may include a user interface 57 (deadman's switch) that may need to be pressed for the interface 53 to be operable. Similarly, the user interface 57 may need to be pressed for the haptic device 51 to send commands to the robotic surgical system 10. In another example, the interface 53 may need to be pressed and held in a pressed position before it can be operated. In yet another example, the haptic device 51 may include one or more sensors, such as a force sensor, a temperature sensor, a proximity sensor, a light sensor, and / or a pressure sensor, to enable one or more controllers 33 to determine whether an operator's hand is in contact with the haptic device 51.

[0105] The haptic device 51 can be utilized in a variety of operating modes, some of which are described in the table of FIG. 11A (the operating modes are referred to as "haptic device operating modes"). As shown, these operating modes include, but are not limited to, an "autonomous check mode," a "manual control mode," a "simulated autonomous check mode," and a "simulated manual control mode." The names of these modes are provided for ease of understanding and explanation, and may be named using any other suitable convention. The functionality of these modes will be fully understood based on the following description.

[0106] Referring to column B of the table in FIG. 11A , in each of the haptic device's operating modes, the one or more controllers 33 provide haptic feedback to the haptic device 51. In the autonomous check mode and the manual control mode, the haptic device 51 emulates the current interaction between the pedicle screw PS and the target site. In the simulated autonomous check mode and the simulated manual control mode, the haptic device 51 emulates the current interaction between a simulated pedicle screw and a simulated target site. All of these modes are initiated automatically by the robotic system 10, manually by an operator, or pursuant to any other command.

[0107] Additionally, the screw position and depth can be displayed on a display device for any of the control modes described herein.

[0108] B. Interaction Sensor For any of the operating modes described herein, the robotic surgical system 10 may include one or more sensors coupled to one or more controllers 33 to obtain measurements indicative of the current interaction between the system's moving elements (such as the implant, the screw, and / or the tool itself) and the target site. For example, the robotic surgical system 10 may include a position sensor configured to sense the position of the pedicle screw PS relative to the target site and / or a rotary encoder configured to sense the rotation of the driver 44 of the surgical tool 30 or the rotation of the pedicle screw PS. The robotic surgical system 10 may include a force sensor configured to sense the force applied to the pedicle screw PS by the target site. The robotic surgical system 10 may also include a torque sensor configured to sense the torque applied to the pedicle screw PS by the target site and / or an electrical parameter sensor configured to sense an electrical parameter generated by the actuator of the surgical tool 30, the electrical parameter being proportional to the torque applied to the surgical tool 30 by the current interaction between the screw and the target site. For example, in such a case, an increase in torque can indicate that the pedicle screw PS has contacted or is about to contact the cortical wall, and a rapid decrease in torque can indicate that the pedicle screw PS has breached the cortical wall and bottomed out. The robotic surgical system 10 may also include a proximity sensor configured to sense the proximity of the pedicle screw PS relative to a feature at the target site, a depth sensor configured to sense the depth of the pedicle screw PS within the target site, and a displacement sensor configured to sense the displacement of the pedicle screw PS relative to a feature at the target site.

[0109] In one embodiment, the navigation system 12 additionally or alternatively determines the current interaction between the pedicle screw PS and the target site. As previously described, preoperative and / or intraoperative imaging can be used to visualize the patient's anatomy. For example, preoperative images, such as X-rays, CT scans, or MRI images, can be used to create an anatomical (virtual) model of the patient's anatomy, specifically the target site. The anatomical model of the target site can be registered to the target site using any suitable registration method. The navigation system 12 can track the robot, the tool, the screws, and / or the patient to determine the position of the pedicle screw PS relative to the anatomical model of the target site. The navigation system 12 can include predetermined data indicating the expected interaction between the pedicle screw PS and the anatomical model at multiple positions of the pedicle screw PS relative to the anatomical model. In one example, the data can be stored in a look-up table in memory for access by one or more controllers 33. The navigation system 12 can obtain measurements indicative of the current interaction between the pedicle screw PS and the target site based on the determined state, position, orientation, and / or posture of the screw relative to the anatomical model and predetermined data. The predetermined data can include bone mineral density data of the vertebra V. The navigation system 12 can use the bone mineral density data and the state of the screw relative to the anatomical model of the vertebra V to obtain measurements indicative of the current interaction between the pedicle screw PS and the vertebra V, for example, at depth A shown in FIG. 12A . The predetermined data can also include known data about the shape of the screw, the tool, or any other features relevant to defining the interaction.

[0110] Any combination of the above sensors, including the navigation system 12, may be combined to provide sensing between the moving element and the target site.

[0111] C. Haptic Interaction Feedback The controller 32 may be configured to provide physical feedback to the haptic device 51, thereby emulating the current interaction between the pedicle screw PS and the target site. As described below, the physical feedback may take a variety of forms.

[0112] Any of the control modes described herein, "autonomous check mode," "manual control mode," "simulated autonomous check mode," and "simulated manual control mode," can fully utilize any of the haptic interaction feedback techniques described herein.

[0113] To enable these techniques, the haptic device 51 may include one or more sensors 65 for sensing characteristics of the haptic device 51, as shown in Figure 10. For example, the one or more sensors may detect any measurement related to the actuator 55, the interface 53, any combination thereof, or any other function. Such sensors 65 may be implemented as position or displacement sensors, incremental / absolute encoders, angle sensors, potentiometers, Hall effect sensors, inductive sensors, capacitive sensors, inertial sensors such as accelerometers, velocity / speed sensors, inclinometers, gyroscopes, force sensors, torque sensors, strain gauge sensors, or any combination thereof or equivalent.

[0114] In some implementations, the one or more controllers 33 are configured to modify or limit mechanical movement of the interface 53 using means other than, or in addition to, the actuators 55. For example, to affect movement of the interface 54, the haptic device 51 may use mechanical components, including but not limited to, biasing mechanisms, detents, ratchets, and / or gear systems, electrical components, including but not limited to, inductive, capacitive, and / or resistive elements, magnetic components, electromagnetic components, electromechanical components, hydraulic components, and / or pneumatic components.

[0115] In some embodiments, the one or more controllers 33 are configured to interfere with the ability to manually manipulate the interface 53. For example, the one or more controllers 33 can determine that a condition exists in the control of the pedicle screws PS and, in response, can provide haptic feedback to the operator regarding the condition by controlling the actuators 55 of the haptic device 51 to interfere with the ability to rotate the rotation interface 53. For example, the condition can include an error condition that would interfere with the ability to rotate the rotation interface 53. These stopping conditions include the pedicle screw PS reaching a desired depth, the pedicle screw PS being rotated a predetermined number of times, a prediction of the contact point between the pedicle screw PS and the bone (described in U.S. Patent Application Publication No. 2017 / 0000572, entitled "Robotic Surgical Systems And Methods For Controlling A Tool Removing Material From A Workpiece," by Moctezuma de la Barrera et al., filed June 28, 2016, and incorporated herein by reference), and / or the operator's subjective knowledge of the stopping point (e.g., the operator may set the amount of time to rotate each pedicle screw PS). Additionally, the conditions may include an error condition, such as a fault detected within the robotic surgical system 10. In some examples, instead of preventing rotation of the rotation interface 53, the robotic surgical system 10 can provide haptic feedback to the operator via vibrations and / or pulses. For example, the one or more controllers 33 can vibrate the haptic device 51 when the pedicle screw PS reaches a desired depth.

[0116] Any of the above haptic techniques can be utilized individually or in combination for any mode or example described herein, or their equivalents. Additionally, one or more controllers 33 can change or modify any of the haptic techniques in response to any condition, such as an interaction sensor, a reading from a sensor 65 of the haptic device 51, a change or initiation of a control mode, or based on input by an operator. Additionally, any of the techniques described herein can be adapted to the rotary or linear interface of the haptic device 51.

[0117] 1. Haptic feedback – resistance or torque In one example, the physical feedback is a resistive force applied to the interface 53. The actuator 55 can adjust the force or torque required to manipulate the interface 53 by the operator's hand. The force required to manipulate the rotational interface 53 can reflect the current force required to rotate the screw relative to the target site. Because the interface 53 is coupled to the actuator 55, the actuator 55 can generate a resistive force to resist movement in a degree of freedom of the interface 53.

[0118] For example, referring to FIG. 12A, the current force required to rotate the pedicle screw PS is F PS and the resistive force provided to the actuator 55 is F A and the force required to rotate the rotating interface 53 is F RI It is shown as F RI When the operator manually operates the rotary interface 53, F RI At various depths along the trajectory LH, the current force F PS The magnitude of the resistance force F A and force F RI changes.

[0119] The controller 32 can control the actuator 55 to adjust, modify, amplify, or dynamically change the resistive force. To do so, the controller 32 can change the operating voltage, frequency, or current of the actuator 55. The resistive force can be modeled or implemented as a spring force, a damper force, an impact force, etc. Additionally, the resistive force can be based on position, velocity, and / or acceleration parameters.

[0120] In some examples, the robotic surgical system 10 may include a resistive force F provided to the actuator 55. A In addition, the robotic surgical system 10 may be configured to receive input from an operator to selectively adjust the sensitivity of the interface 53's ability to control the surgical tool 30 to rotate the pedicle screw PS. In some examples, the resistance force F A and the sensitivity of the interface 53 are related. For example, the resistance force F A The larger the resistance force F A The smaller the , the less sensitive the interface 53. Parameters that may be adjustable to change the sensitivity of the interface 53 include, but are not limited to, spring parameters, damping parameters, force parameters, a scaling factor between the rotational ratio of the actuator 55 and the interface 53, actuator parameters, force magnitude, force direction, displacement limits or ranges of the interface 53 for any given resistance force, resistance force curve or slope, etc. For example, if the interface 53 includes a spring and a spring parameter is adjusted, such spring parameter may be a spring constant, where a larger spring constant requires a larger force to actuate the interface 53. In such cases, the spring may be formed from an elastic element such that the spring constant can be changed by changing the material properties of the elastic element or by changing the geometric properties of the elastic element.

[0121] In one example, the resistive force may be a restoring force having a magnitude proportional to the magnitude of the deviation of the interface 53 from a home position (zero detent) defined on the interface 53 or between the interface 53 and the actuator 55. The home position may be, for example, the position of the interface 53 defined by the controller at the moment the haptic mode is initiated. In one example, the home position is defined at a static position relative to the haptic device 51. In another example, the one or more controllers 33 may dynamically adjust the location of the home position based on any pre-existing conditions, such as an interaction sensor, readings from the sensors 65 of the haptic device 51, a change or initiation of a control mode, completion of a task, or based on input by an operator. Alternatively, the home position may be pre-defined mechanically, for example, using a physical detent, etc.

[0122] In some embodiments, the resistance force may yield to movement of the interface 53. In other words, the resistance force does not attempt to restore the position of the interface 53 to any home position. The resistance force may be initially small in magnitude and increase in magnitude as the interface 53 moves farther from the home position.

[0123] In some instances, the resistance force increases to a magnitude necessary to communicate to the user that the screw PS has reached its limit relative to the target site. For example, this may be appropriate in situations where the screw may abut the inner cortical wall of the vertebral body, thereby providing a limit to avoid cortical wall fracture. In one example, the resistance force can be modeled as a barrier force effect with a large stiffness magnitude. Alternatively, in such cases, the controller can control the actuator 55 to apply a mechanical limit to the movement of the interface 53.

[0124] In many examples, a resistive force is applied to resist rotational motion. However, a resistive force can also be applied to resist linear motion. For example, a linear motion may resist linear movement of the interface 53. Such linear motion may be the movement of a mechanism of the linear interface 53, such as a slider, a push button, or the like. Alternatively or additionally, the linear motion may be an example in which the rotational interface 53 can be depressed. The resistive force in such an example may resist depression of the rotational interface 53.

[0125] The resistance force may be provided in response to different conditions related to the current interaction between the pedicle screw PS and the target site, any of which may be detected by any of the interaction sensors described above.

[0126] In one example, a resistance force is applied to the interface 53 depending on the rotational position of the pedicle screw PS. The position of the screw PS relative to a reference point is determined. The resistance force applied to the interface 53 can be incrementally increased or decreased until the screw reaches a specified position. In this example, a home position of the interface 53 can be utilized. The interface 53 can be rotated away from the home position to command the screw to be driven. While in a non-home position, a resistance force is applied to the interface 53. However, once a specific position is reached, the resistance force can be zeroed, and the interface 53 can bounce back to the home position. Alternatively, the resistance force can be incrementally reduced (to zero) as the screw gradually approaches reaching a specific position.

[0127] In another example, a resistance force is applied to the interface 53 depending on the insertion depth of the pedicle screw PS. In this example, a home position for the interface 53 can be utilized. The interface 53 can be rotated away from the home position to command the screw to be driven. While in the non-home position, a resistance force is applied to the interface 53. However, once the insertion depth is reached, the resistance force can be zeroed and the interface 53 can bounce back to the home position. Alternatively, the resistance force can be gradually reduced (to zero) as the screw gradually approaches reaching the insertion depth.

[0128] In another example, a resistance force is applied to the interface 53 depending on the rotational speed of the pedicle screw PS. In this example, a home position for the interface 53 may be utilized. The interface 53 may be rotated away from the home position to command the screw to be driven. While in the non-home position, the resistance force may be gradually increased or decreased depending on the rotational speed of the screw.

[0129] In another example, the resistance force is applied to the interface 53 in response to torque applied to the pedicle screw PS by the target site or in response to torque applied by a tool.

[0130] In another example, the one or more controllers 33 can also provide haptic feedback to the operator via vibrations and / or pulses. For example, the one or more controllers 33 can adjust the frequency and / or amplitude of vibrations of the haptic device 51 based on the current force required to rotate the screw relative to the target site. In a more specific example, as the force required to rotate the screw relative to the target site increases, the amplitude of vibrations of the haptic device 51 may increase and the frequency of vibrations of the haptic device 51 may decrease. Similarly, as the force required to rotate the screw relative to the target site decreases, the amplitude of vibrations of the haptic device 51 may decrease and the frequency of vibrations of the haptic device 51 may increase.

[0131] The resistance force may be implemented using any combination of the embodiments described herein, or equivalents thereof.

[0132] 2. Haptic Feedback – Position The interface 53 may employ feedback techniques other than resistance force. In one example, the position of the interface 53 is actively controlled (moved) by an actuator 55 depending on the current interaction between the screw PS and the target site, providing feedback to the operator. Any of these conditions can be detected by any of the interaction sensors described above.

[0133] In one example, the position of the interface 53 is controlled according to the rotational position of the pedicle screw PS. The position of the interface 53 can be actively rotated by the actuator 55 based on the real-time position of the screw. As the screw rotates, the interface 53 also rotates. In another example, the position of the interface 53 can be moved to or between specific fixed positions to inform the operator of any positional information related to the screw, such as maximum position or insertion depth. The interface 53 can include a graphic scale or indicia to correlate the interface position to the screw position.

[0134] In another example, the position of the interface 53 is controlled in response to torque applied to the pedicle screw PS by the target site or in response to torque applied by a tool. The position of the interface 53 can be actively moved by the actuator 55 to indicate to the operator the various torque levels the screw is subjected to. The interface 53 can include a graphic scale or indicia to correlate the interface position to the screw torque.

[0135] In yet another example, the position of the interface 53 is controlled in response to the rotational speed of the pedicle screw PS. The position of the interface 53 can be actively moved by the actuator 55 to indicate to the operator the various speed levels the screw is subjected to. The interface 53 can include a graphic scale or indicia to correlate the interface position to the tool or screw speed.

[0136] 3. Haptic Feedback – Range of Motion In another example, the position of the interface 53 is controlled to be limited depending on the current interaction between the screw PS and the target site to provide feedback to the operator. Any of these conditions can be detected by any of the interaction sensors described above.

[0137] In one example, the interface 53 is limited to only being allowed to rotate an amount related to the amount the screw has been turned. In another example, the interface 53 is limited to only being allowed to rotate an amount related to the depth to which the screw has been inserted. In another example, the interface 53 is limited to only being allowed to rotate an amount that identifies where the screw has reached a physical or virtual boundary.

[0138] In another embodiment, when interface 53 is rotating, its range of motion can be controlled to allow continuous rotation, for example, any number of full 360 degree rotations. This can be appropriate in certain control modes, such as when haptic device 51 is utilized to allow a user to manually control screw insertion by controlling the rotational interface 53 to reach a speed or force / torque for input control, as described below.

[0139] D. Autonomous Check Mode One mode of the haptic device 51 is an autonomous check mode. During the autonomous check mode, the robotic surgical system 10 provides haptic feedback to the operator to emulate the current interaction between the pedicle screw PS and the target site as the robotic system 10 autonomously inserts the screw PS. During the autonomous check mode, the rotational interface 53 controls the force F RI and the current force F required to rotate the pedicle screw PS relative to the vertebra V. PS In other words, the autonomous check mode allows the operator to "feel" the screw interaction at any time before, during, or after autonomous screw insertion.

[0140] As shown in columns B and D of the table in FIG. 11A, tactile feedback is provided to the haptic device 51 for checking, but the haptic device 51 does not control the surgical tool 30 or driver 44 to insert the pedicle screw PS during the autonomous check mode because the screw is being inserted autonomously by the robotic system 10 (see column D in FIG. 11A).

[0141] FIG. 12A provides an example of a pedicle screw PS interacting with a target site, a vertebra V, during an autonomous check mode. In FIG. 12A , the one or more controllers 33 autonomously control the insertion of the pedicle screw PS along a planned trajectory LH. In this case, the screw is self-tapping. Meanwhile, the one or more controllers 33 control the haptic device 51 to emulate the current interaction between the pedicle screw PS and the vertebra V. For example, when the pedicle screw PS is inserted along the planned trajectory LH to a depth A, the one or more controllers 33 control the haptic device 51 to emulate the current interaction between the pedicle screw PS and the vertebra V at the depth A. Thus, the system 10 provides the operator with haptic sensations that allow them to experience the screw PS insertion being performed by the robotic system.

[0142] In one example, as outlined in column F of the table in FIG. 11A , the autonomous check mode can be performed simultaneously with / during active and autonomous screw insertion by the robotic system 10. In such a case, by initiating the autonomous check mode, the rotational interface 53 is controlled to be manually operable so that an operator can receive haptic feedback from the robotic surgical system 10 via the rotational interface 53 as the screw is being inserted autonomously. In this example, the autonomous screw insertion does not stop for the haptic check. As the screw PS continues to be inserted autonomously, the insertion depth continuously changes, thereby changing the current interaction between the pedicle screw PS and the vertebra. Therefore, in this example, the resistance feedback to the rotational interface 53 can be modified to reflect the near real-time current interaction between the pedicle screw PS and the vertebra. The resistance force update can be set according to any suitable time step, such as every N seconds, every N degrees of screw rotation, or every N mm of screw displacement.

[0143] Alternatively, as outlined in column F of the table in FIG. 11A , the autonomous check mode can be initiated after one or more controllers 33 autonomously control the surgical tool 30 to stop or pause the rotation of the pedicle screw PS. In one example, the robotic system 10 stops or pauses autonomous control in response to an operator triggering the autonomous check mode. Alternatively, the robotic system 10 stops or pauses autonomous control in response to any other system command, such as a user-initiated stop of autonomous motion. In either case, the system 10 controls the haptic device 51 to emulate the interaction between the pedicle screw PS and the vertebrae that exists when the system 10 is stopped or paused. After the autonomous check mode is executed, the operator can resume autonomous control of the robotic system 10 to continue inserting the screw.

[0144] In another example, as outlined in column F of the table in FIG. 11A , the robotic surgical system 10 can initiate an autonomous check mode before one or more controllers 33 autonomously control the surgical tools 30 to insert the pedicle screws PS. For example, an operator may be interested in haptic feedback of the pedicle screws PS before one or more controllers 33 autonomously control the surgical tools 30 to insert the pedicle screws PS. In such a case, the screws PS may be partially implanted following manual insertion by the surgeon and then inserted autonomously at a later time. The existing interaction between the partially implanted screws PS and the target site may be reflected in the haptic device 51 for the surgeon to check before initiating autonomous insertion.

[0145] In some examples, initiation of the autonomous check mode automatically initiates autonomous control of the surgical tool 30 by the one or more controllers 33. Similarly, deactivation of the autonomous check mode can cause the one or more controllers 33 to cease autonomous control of the surgical tool 30. Alternative examples of the autonomous check mode, their functionality and uses are discussed.

[0146] E. Manual control mode In the manual control mode, the operator utilizes the haptic device 51 to control the surgical tool 30 for purposes such as, but not limited to, inserting the pedicle screws PS. During the manual control mode, the one or more controllers 33 do not autonomously control the insertion of the pedicle screws PS (as shown in row D of FIG. 11A ). Instead, the interface 53 of the haptic device 51 is operated to provide input to the one or more controllers 33 to control the insertion of the pedicle screws PS. In response to the control input from the haptic device 51, the one or more controllers 33 control the surgical tool to rotate the screws at a rotational speed about the rotation axis R and linearly advance the screws at an advancement speed along the planned trajectory LH.

[0147] The manual control mode can be utilized before or after any of the other haptic device modes described herein. In one example, the robot can autonomously insert a screw to a desired or predetermined torque peak, insertion depth, or number of screw turns. The manual control mode can then be utilized to complete the remainder of the task.

[0148] 1. Manual control input Referring to column G of the table in FIG. 11A for manual control mode, one or more controllers 33 may be configured to determine or receive an input control technique that defines how the haptic device 51 may be utilized as input.

[0149] 11B, examples of these input control techniques include, but are not limited to, utilizing the haptic device 51 as a force or torque input, a rotational position input, or a rotational speed input. The input control technique can be set according to the surgeon's preference, specified by the system, or any combination thereof. The operator can select the input control technique using the user interface 57 (shown in FIG. 10) of the haptic device 51 or by other methods, such as input to the display device 18.

[0150] In manual control mode, the tool is controlled to insert the screw in response to input from the haptic device 51. As described below, there are also various output technologies for controlling the screw, which may be the same or different from the technology utilized for input control.

[0151] a. Force or torque input from a haptic device 11B, one example input provided by haptic device 51 is a force or torque input applied by the operator to interface 53. As shown in FIG. in The interface 53 can be manually operated by applying the force F inmay also be an applied torque. The one or more controllers 33 may obtain measurements of the force applied to the interface 53 to determine a desired force for inserting the pedicle screw PS and control the insertion of the pedicle screw PS based on the desired force. The applied force or torque may represent a force or torque desired by the operator between the screw PS and the target site.

[0152] For example, the one or more controllers 33 may be configured to generate a force F used to manually manipulate the rotational interface 53 from a home position P0 to a non-home position P1, as shown in FIG. 11C. in Based on this, the desired force for inserting the pedicle screw PS can be determined. In each of these examples, position P1 is shown only as one possible example of many positions that the interface 53 may be in relative to the home position. In one example, the one or more controllers 33 may be configured to allow the operator to apply a force F in By measuring or calculating the torque applied to the rotating interface 53 when applying in In another example, the one or more controllers 33 may be configured to obtain a measurement of the force F in By determining the acceleration of the rotating interface 53 when applying the force F in The device may be configured to obtain measurements of:

[0153] In one example, if the robotic surgical system 10 includes a surgical tool 30 having a trigger 49 as shown in Figures 4-6, the operator can control the insertion of the pedicle screw PS by manually manipulating the trigger 49 instead of the rotational interface 53 of the haptic device 51. In such a case, the operator can apply a force F in A trigger 49 can be depressed at , which can transmit a signal to one or more controllers 33 indicative of the operator's input.

[0154] The interface 53 may include a zero detent (home position P0) so that when released by the operator after applying a force, the interface 53 returns to the home position. In this way, the operator can apply a series of forces F without unnecessary hand movement. in can be applied to the rotational interface 53. In another example, the interface 53 can continue to rotate with a degree of freedom unimpeded, allowing sufficient rotation of the interface 53 to achieve the desired force. Thus, the rotational interface 53 provides a full 360-degree range of motion, allowing an operator to simulate rotating a screw by hand.

[0155] b. Position input from a haptic device In another example, the one or more controllers 33 can obtain measurements of the position (or change in position) of the interface 53 to provide control input. For example, if an operator manually manipulates the rotational interface 53 from a home position P0 to a position P1, the one or more controllers 33 can determine a desired rotational position of the pedicle screw PS based on the location of position P1 relative to the location of the home position P0. In some examples, the one or more controllers 33 can obtain measurements of the rotational angle of the rotational interface 53 at position P1 relative to the home position P0. The position can be determined using any suitable sensor, such as an incremental or absolute encoder coupled to the interface 53 and / or the actuator 55. The displacement of the interface 53 relative to the home position P0 can also be utilized to provide input. Alternatively, the position of the interface 53 relative to a full degree of movement (e.g., 360 degrees) of the interface 53 can be utilized as an input regardless of the home position. The position can also take into account the cumulative number of rotations of the interface 53 relative to a full degree of movement (e.g., 1.5 rotations or 540 degrees).

[0156] In one example, interface 53 may include a zero detent (home position P0) so that interface 53 returns to the home position when released by the operator at the desired position. In another example, interface 53 may continue to rotate with an unimpeded degree of freedom to allow sufficient rotation of interface 53 to achieve the desired position.

[0157] c. Velocity input from a haptic device In yet another example, the input provided by the haptic device 51 is the velocity experienced by the interface 53 in response to the operator's manipulation. The one or more controllers 33 can obtain measurements of the velocity of the interface 53 using any suitable sensing device, such as an inertial sensor, an encoder, or a Hall-effect sensor. For example, as shown in FIG. 11B, assume that the interface 53 is at a home position P0 at time T0 and the operator manually manipulates the interface to move to position P1 at time T1. The one or more controllers 33 can determine the distance or displacement between P1 and P0 over time T1-T0 to determine the velocity of the interface 53. This distance or displacement can be linear or angular. The one or more controllers 33 can utilize any suitable software or logic for calculating velocity based on sensed readings, such as an integrator, a differentiator, a look-up table, or the like.

[0158] In one example, interface 53 may include a zero detent (home position P0) so that interface 53 returns to the home position when released by the operator. In another example, interface 53 may continue to rotate with an unimpeded degree of freedom to allow sufficient rotation of interface 53 to achieve the desired velocity input.

[0159] The input control from the haptic device 51 can be any combination of force, position, and / or velocity.

[0160] 2. Manual control output The system 10 is configured to control the insertion of the screw in response to control input from the haptic device 51 utilizing any of the input techniques (force, position, velocity) described above. Referring to FIG. 11B, the tool can be controlled to drive the screw according to a variety of output control techniques. These output control techniques include force, rotational position, insertion depth, and velocity. These output control techniques are described in more detail below, and the output control techniques can be utilized in response to any of the input techniques (force, position, velocity).

[0161] The one or more controllers 33 may be configured to determine or receive an output control technique (i.e., force, rotational position, insertion depth, and speed) that defines how the tool should be operated in manual control mode. The output control technique can be set according to the surgeon's preference, specified by the system, or any combination thereof. The operator can select the output control technique using the user interface 57 (shown in FIG. 10) of the haptic device 51 or by other methods, such as input to the display device 18.

[0162] In all examples of manual control mode output, the screw rotation and advancement speed are coupled by thread pitch in accordance with the techniques described herein. Additionally, the sensitivity of interface 53 for triggering tool control can be modified for any of the examples described herein. The sensitivity of interface 53 can be updated manually or automatically to take bone density into account.

[0163] a. Tool force output control In response to any input technique (force, position, velocity), one or more controllers 33 can act on the tool to drive the screw PS based on force control.

[0164] In one example, the input position of interface 53 determines the force output by tool 30 to the screw. The force output can be torque. In one example, the input position of interface 53 can determine a specific force or torque level that the tool should apply to the screw, and tool 30 is controlled to apply the specified force or torque. In another example, the position of interface 53 can determine a maximum force or torque level that the tool should apply to the screw, and the robot and tool 30 continue to insert the screw until the maximum force or torque is achieved. In these examples, interface 53 can include a zero detent (home position P0) so that interface 53 returns to the home position when released by the operator.

[0165] In one example, the input speed of interface 53 determines the force output to the screw by tool 30. For example, an increase / decrease in the speed of interface 53 may cause an increase / decrease in the torque applied to the screw by the tool. In this example, the user may need to turn interface 53 faster and faster to achieve full screw insertion.

[0166] In yet another example, an input force or torque applied to interface 53 causes the tool to apply a force or torque output to drive the screw. In one example, the input force or torque to interface 53 can determine a particular force or torque level that the tool should apply to the screw, and the tool 30 is controlled to apply the specified force or torque. Alternatively, the input force or torque to interface 53 can determine a maximum force or torque level that the tool should apply to the screw, and the robot and tool 30 continue to insert the screw until the maximum force or torque is achieved.

[0167] b. Tool rotation position output control In response to any input technique (force, position, velocity), one or more controllers 33 can act on the tool to drive the screw PS based on rotational position control, which can be defined as the rotational angle of the screw relative to a reference angle.

[0168] In one example, an input position of the interface 53 causes the tool to rotate the screw PS to a certain position, or a displacement of the interface 53 causes the tool to rotate the screw PS according to the displacement.

[0169] In another example, a speed input on interface 53 causes the tool to rotate the screw PS to a certain position. An increase / decrease in the input speed on interface 53 can also cause a change in the output position control. In this example, the user may need to turn interface 53 faster and faster to achieve full screw insertion.

[0170] In another example, a force or torque input at interface 53 causes the tool to rotate the screw PS to a certain position. In one example, the force or torque input at interface 53 can determine a specific position to which the tool should drive the screw. Alternatively, the force or torque input at interface 53 can determine a maximum position to which the tool should drive the screw, and the robot and tool 30 continue to insert the screw until the maximum position is reached.

[0171] c. Tool insertion depth output control In response to any input technique (force, position, velocity), one or more controllers 33 can act on the tool to drive the screw PS to a particular insertion depth within the target site.

[0172] In one example, an input position of the interface 53 causes the tool to rotate the screw PS to a particular insertion depth, or a displacement of the interface 53 causes the tool to rotate the screw PS according to the insertion depth.

[0173] In another example, a speed input on interface 53 causes the tool to rotate the screw PS to a specific insertion depth. Increasing / decreasing the input speed on interface 53 can also cause a change in insertion depth. In this example, the user may need to turn interface 53 faster and faster to achieve the full insertion depth.

[0174] In another example, the force or torque input of interface 53 causes the tool to rotate the screw PS to a particular insertion depth. In one example, the force or torque input of interface 53 can determine a particular insertion depth to which the tool should drive the screw. Alternatively, the force or torque input of interface 53 can determine a maximum particular insertion depth to which the tool should drive the screw, and the robot and tool 30 continue to insert the screw until the particular insertion depth is reached.

[0175] d. Tool speed output control In response to any input technique (force, position, velocity), one or more controllers 33 can act on the tool to drive the screw PS based on velocity control, which can be defined by the change over time of the screw rotation angle, the linear screw insertion rate, the tool rotation rate, or any combination thereof.

[0176] In one example, an input speed of the interface 53 causes the tool to rotate the screw PS according to the associated speed. Alternatively, a displacement of the interface 53 causes the tool to rotate the screw PS according to the associated speed.

[0177] In another example, a speed input on interface 53 causes the tool to rotate screw PS according to the associated speed. An increase / decrease in the input speed on interface 53 may also cause a change in the output speed control. In this example, to achieve a particular speed, the user may need to turn interface 53 faster and faster.

[0178] In another example, a force or torque input at interface 53 causes the tool to rotate the screw PS according to an associated speed. In one example, the force or torque input at interface 53 can determine a particular speed at which the tool should drive the screw. Alternatively, the force or torque input at interface 53 can determine a maximum speed at which the tool should drive the screw, and the robot and tool 30 continue to insert the screw until the maximum speed is reached.

[0179] e. Input and output relationships Described above are various input control techniques provided by the haptic device 51 and various output control techniques for driving a tool. The relationship between the input of the haptic device 51 and the output to the tool can be defined according to various configurations described below. The relationship between the input of the haptic device 51 and the output to the tool can be defined according to any combination of various configurations described below.

[0180] The one or more controllers 33 can map inputs of the haptic device 51 to predetermined outputs to the tool, which can correspond to default settings for the tool. For example, the memory of the one or more controllers 33 can include a lookup table in which inputs of the haptic device 51 correspond to predetermined default outputs to the tool. In one such example, the one or more controllers 33 can obtain measurements where the interface 53 is rotated 30 degrees. Then, based on the lookup table, the one or more controllers 33 can determine that the pedicle screw PS should be rotated at a rotational speed of 1.5 rotations per second.

[0181] The one or more controllers 33 can map the inputs of the haptic device 51 to predetermined outputs to the tool, which can be based on various variables. For example, the predetermined outputs to the tool can be based on a condition of the haptic device 51, which can be detected by any of the interaction sensors or sensors 65 described above. For example, the predetermined outputs can be based on the insertion depth of the pedicle screw PS, the current force F required to rotate the pedicle screw PS, PS , and / or bone density data of vertebra V. As another example, the predetermined output to the tool can be based on readings sensed by sensors 65 of user interface 57 of haptic device 51. For example, user interface 57 can include a push button that can be pressed for a "sensing" control, or a slider that can be actuated to indicate a desired sensitivity of the control. The predetermined output can be based on the desired sensitivity of the control, as sensed by sensors 65.

[0182] The one or more controllers 33 can map the relationship between the input and output based on any suitable mathematical function, such as monotonic, linear (e.g., proportional), exponential, logarithmic, polynomial, root, power, and rational functions. In one example, the one or more controllers 33 can map the measured position to the desired insertion depth based on a linear function, such that the amount of angle the rotational interface 53 rotates is proportional to the desired insertion depth. For example, for every degree the rotational interface 53 is rotated, the one or more controllers 33 increase the desired insertion depth by 1 / 90 of a millimeter. In another example, the one or more controllers 33 can map the measured position to the rotational speed based on a piecewise constant function (i.e., a floor function). In such a case, the one or more controllers 33 can map the measured positions to desired rotational speeds such that when the rotating interface 53 rotates between 1 degree and 180 degrees (inclusive), the one or more controllers 33 determine the desired rotational speed to be 1 revolution / second, and when the rotating interface 53 rotates between 181 degrees and 360 degrees (inclusive), the one or more controllers 33 determine the desired rotational speed to be 2 revolutions / second.

[0183] The one or more controllers can map any input technique (force, position, velocity) to an output control of the tool (force, rotational position, insertion depth, velocity) based on the mapping relationship between the input of the haptic device 51 and the output to the tool.

[0184] As shown in column D of FIG. 11B, the force input can be mapped to a rotational position output, an insertion depth output, a force output, or a velocity output. For example, the force input can be linearly mapped to a rotational position output, resulting in a measure of the force input (F inThe force input (measurement of force) can be mapped to a proportional screw rotation angle. Similarly, the force input can be linearly mapped to insertion depth output, force output, and velocity output, such that the force input can be mapped to a proportional screw insertion depth, a proportional torque applied to the pedicle screw PS, and a proportional velocity of screw insertion.

[0185] As shown in column D of FIG. 11B , the position input may be mapped to a rotational position output, insertion depth output, force output, or velocity output. For example, the position input may be linearly mapped to a rotational position output, such that a measurement of the position input (a measurement of position P1 or a measurement of the displacement between positions P1 and P0) may be mapped to a proportional screw rotation angle. Similarly, the position input may be linearly mapped to an insertion depth output, a force output, and a velocity output, such that a measurement of position P1 relative to home position P0 may be mapped to a proportional screw insertion depth, a proportional maximum torque level that needs to be applied to the pedicle screw PS, and a proportional velocity of screw insertion.

[0186] As shown in column D of FIG. 11B , the velocity input can be mapped to a rotational position output, insertion depth output, force output, or velocity output. For example, the velocity input can be linearly mapped to a rotational position output, such that a measurement of the velocity input (a measurement of the displacement between P1 and P0 over time T1-T0) can be mapped to a proportional screw rotation angle. Similarly, the velocity input can be linearly mapped to an insertion depth output, a force output, and a velocity output, such that the velocity input can be mapped to a proportional screw insertion depth, a proportional torque applied to the pedicle screw PS, and a proportional speed of screw insertion.

[0187] F. Simulated Mode The technology associated with the haptic device 51 described above relates to intraoperative techniques that utilize physical robotic control and / or drive to tools. However, it is contemplated that the haptic device 51 may be utilized to perform simulations to provide training or greater confidence to an operator in using a robotic system prior to performing an actual surgical procedure. Referring to the table in FIG. 11A and FIGS. 14A-14C, there are various simulated modes that may be utilized with the haptic device 51. These modes include a simulated autonomous check mode and a simulated manual control mode, which are described in more detail below.

[0188] The simulation mode can simulate the entire operating room conditions that may exist during surgery, including, but not limited to, the patient, robotic system, robotic manipulator, patient table, navigation system, tools, and screws. Alternatively, the simulation can simulate screws and target site, tools, screws, and target site, or robotic manipulator, tools, screws, and target site. Additionally, the reference simulation can provide a surgical plan including target trajectory and insertion depth.

[0189] The simulation can be run on any suitable graphical display device, such as, but not limited to, one or more of the display 18 of the robotic system 10 or displays outside the operating room. One or more controllers 33 can run the simulation. Alternatively, the haptic device 51 can be connected to a simulation system separate from the robotic system 10, where the simulation system has its own control system.

[0190] The simulated modes described herein can be performed pre-operatively or intra-operatively. For example, a surgeon can run a simulation in the operating room immediately prior to directing the execution of physical robotic controls. Alternatively, the simulation can be run pre-operatively. In either case, the surgeon can set, confirm, or modify any operational parameters of the system 10 that will be experienced during the simulation. For example, the surgeon can set, confirm, or modify the surgical plan, such as pedicle screw size, insertion depth, and pedicle entry point location; haptic device operation or sensitivity; preferred haptic device control input technique (force / torque, position, velocity); tool operation, feed rate, linear advancement speed, rotational speed, or sensitivity; tool-appropriate control output technique (force / torque, position, velocity); robot parameters, such as pose and orientation; and the like.

[0191] As previously described, preoperative and / or intraoperative imaging can be used to visualize the patient's anatomy. For example, preoperative images, such as X-rays, CT scans, or MRI images, can be used to create an anatomical model of the patient's anatomy, specifically the target site. This virtual anatomical model can be utilized in the simulation. Additionally, once the thread forms of the pedicle screws PS are stored in the memory of the robotic surgical system 10, the selected pedicle screws PS can be virtually presented within the simulation.

[0192] During the simulated mode, the one or more controllers 33 provide haptic feedback to the haptic device 51. The one or more controllers 33 are configured to control the actuators 55 of the haptic device 51 to enable the rotational interface 53 to emulate the simulated current interaction between the pedicle screw PS and the target site. Referring to Figures 14B and 14C, the one or more controllers 33 may calculate the force F required to rotate the rotational interface 53 by the operator's hand. RI To adjust the resistance force F A, the force required to rotate the rotation interface 53 is shown in FIG. 14C as F SPS , reflecting the simulated current force required to rotate the pedicle screw PS relative to the vertebra V (target site). Of course, the haptic device 51 can be controlled to provide haptic feedback using any technique other than resistive feedback, such as the force, position, or range of motion feedback techniques described above.

[0193] During the simulated mode, the one or more controllers 33 may be configured to acquire a simulated current interaction between the (simulated) pedicle screw PS and the (simulated) target site using various methods. For example, the one or more controllers 33 may acquire virtual measurements corresponding to the simulated current interaction in a simulation coordinate system. The simulation system may track the simulated robot, tool, screw, and / or patient and determine the position of the simulated pedicle screw PS relative to an anatomical model of the target site. The simulation system may include predetermined data indicative of the expected interaction between the simulated pedicle screw PS and the anatomical model at multiple positions of the simulated pedicle screw PS relative to the anatomical model. In one example, the data may be stored in a lookup table in memory for access by the one or more controllers 33. The simulation system may calculate parameters indicative of the simulated current interaction between the pedicle screw PS and the target site based on the determined state, position, orientation, and / or posture of the screw relative to the anatomical model and the predetermined data. The predetermined data may include bone mineral density data of the vertebrae V. The simulation system can use the bone density data and the state of the screw relative to an anatomical model of the vertebra V to calculate or obtain parameters indicative of a simulated current interaction between the pedicle screw PS at various depths and the vertebra V. The predetermined data can also include known data regarding the screw, tool geometry, or other features relevant to defining the interaction.

[0194] 1. Simulated autonomous check mode In a sense, the simulated autonomous check mode is a simulated version of the autonomous check mode. Therefore, the description of the autonomous check mode above can be incorporated herein to understand the simulated autonomous check mode. During the simulated autonomous check mode, the one or more controllers 33 simulate (graphically) autonomously controlling the surgical tool 30, and the operator can tactilely sense the simulated autonomous insertion using the haptic device 51. The one or more controllers 33 simulate autonomously controlling the surgical tool 30 by simulating rotating the pedicle screw PS at a rotational speed about the rotation axis R and simulating linearly advancing the pedicle screw PS at an advancement speed along the planned trajectory LH. However, the robotic system does not physically control the tool's motion. Instead, the one or more controllers 33 simulate autonomous control of the surgical tool 30 (as shown in row E of FIG. 11A ) to simulate autonomously inserting the pedicle screw PS. During the simulated autonomous check mode, the rotation interface 53 applies a regulated force F RI , but without the ability to control the simulated surgical tool 30 to rotate the pedicle screws PS and without the ability to control the simulated autonomous control of the surgical tool 30. Just like the autonomous check mode, the simulated autonomous check mode can be executed before, during, or after stopping / pausing the simulation of autonomous screw insertion.

[0195] 2.Simulated manual control mode In a sense, the simulated manual control mode is a simulated version of the manual control mode. Therefore, the description of the manual control mode above can be incorporated herein to understand the simulated manual control mode. In contrast to the manual control mode, during the simulated manual control mode, the interface 53 is manually operable without the ability to control the (physical) surgical tool 30. Instead, the one or more controllers 33 simulate manual control of the surgical tool 30 (as shown in column E of FIG. 11A ) in response to an operator manually manipulating the interface 53 of the haptic device 51. During the simulated manual control mode, the one or more controllers 33 simulate manually controlling the surgical tool 30 in response to input from the haptic device 51. During the simulated manual control mode, the one or more controllers 33 simulate controlling one of the rotation speed or advancement speed of the pedicle screw PS. The operator can manually manipulate the haptic device 51, and in response, the one or more controllers 33 can simulate controlling one of the rotational speed or advancement speed of the pedicle screw PS (as shown in column G of FIG. 11A ). For example, the operator can manually manipulate the interface 53 using any of the input techniques described above. In response to the control input, the one or more controllers 33 control the output of the simulated tool based on any suitable output technique, such as force, position, or velocity for the simulated insertion of the pedicle screw PS. In this example, as shown in FIG. 14C , the user can manually manipulate the haptic device 51 and, in response, control one of the rotational speed or advancement speed of the pedicle screw PS. in is applied to the interface 53 to perform simulated manual control of screw insertion on the display 18. The input force is converted into the (resistance) force F output by the actuator 55. RI is resisting.

[0196] III. Methods for Controlling a Robotic Surgical System 15A, a flow chart illustrates an example method for controlling the robotic surgical system 10. As shown, the flow chart illustrates the operation of various haptic device operating modes during surgery.

[0197] The flowchart illustrates a method for controlling the robotic surgical system 10 to insert or simulate the insertion of a pedicle screw PS. The method begins at step 200 and proceeds directly to step 202, which involves preparing the anatomy to receive the pedicle screw PS. During step 202, various steps may be performed to prepare the anatomy for insertion of the pedicle screw PS. These steps may include step 1: forming an incision in the patient, step 2: retracting the tissue with a tissue retractor, step 3: placing a cannula through the retracted tissue, step 4: drilling a pilot hole 102 into the anatomy, and step 5: tapping threads into the anatomy. Note that step 202 need not include steps 1-5 above. For example, in alternative examples, drilling the pilot hole 102 and tapping threads into the anatomy may be omitted, thereby excluding steps 4 and 5. For example, such examples include those in which self-drilling, self-tapping bone screws are used.

[0198] The method then proceeds to step 204, where the pedicle screw PS is interacted with by the surgical tool 30. In some embodiments, the tool 30 is coupled to the screw PS before interacting with the anatomy. Alternatively, the pedicle screw PS can be partially seated into the target site anatomy using any technique, including manual or robotic insertion, and then the tool 30 interacts with the partially seated screw PS. More likely, the pedicle screw PS is attached to the distal end of the driver 44 for placement into one of the pilot holes 102. The original line haptic object can be used to insert the pedicle screw PS, or a new line haptic object including a new start point, target point, and exit point can be created when installing the driver 44 and / or pedicle screw PS. In this case, the drill 42 and / or driver 44 may include an RFID tag or other identification device so that one or more robotic controllers 33 can identify accessories coupled to the housing 45. The housing 45 includes a corresponding RFID reader or the like that can communicate with one or more controllers 33 to read the tag and determine which accessories are attached. Based on this information, the controller can then create, access, or otherwise determine a new line haptic object. Similarly, the pedicle screws PS can also be equipped with RFID tags, and the driver 44 can include a similar reader, so that the one or more controllers 33 can also determine the size / type of pedicle screw PS to be attached. Thus, the line haptic object can be based on the driver 44 and / or the pedicle screw PS, thereby precisely controlling the robotic arm 20 to place that particular pedicle screw PS in a desired location, e.g., at a desired orientation and depth relative to the patient's anatomy.

[0199] Additionally, automatic detection of an accessory, either via an RFID tag or other detection device such as a vision camera, can cause the control system to advance any surgical software utilized by the robotic surgical system 10 to the next screen associated with the driver 44, where the driver 44 is coupled and thus can provide different prompts, instructions, etc., for the operator. Voice recognition, gesture sensing, or other input devices can be used to advance the software and / or change to the next vertebra 100 to be treated and / or change the side of the vertebral body 100 on which surgery is being performed. This can also be based on the position of the surgical tool 30. For example, if the operator manually positions the TCP of an attached accessory closer to one side of the vertebra V than the other side, the software can automatically advance to accommodate that side of the vertebra V. The selected vertebra V and side of surgery can be confirmed visually by the display 18 or via audio input / output.

[0200] In some surgeries, the rotation axis R may deviate from the desired trajectory between drilling the pilot holes 102 and inserting the pedicle screws PS, such as when all pilot holes 102 are drilled first and then all pedicle screws PS are inserted into their desired positions. In such cases, before placing each pedicle screw PS, the robotic surgical system 10 can initially control the motion of the surgical tool 30 to position the rotation axis R along the desired trajectory by autonomously aligning the rotation axis R of the surgical tool 30 with the desired trajectory for each pedicle screw PS in the manner described above.

[0201] The method proceeds to step 208, where if the operator does not terminate the surgical action during step 206, the one or more controllers 33 determine which haptic device operating mode is selected (step 206 is described in more detail below). The haptic device operating mode can be selected in response to any condition or command. During step 210, the method determines whether the selected haptic device operating mode is currently being executed by the one or more controllers 33. If the selected haptic device operating mode is not being executed by the one or more controllers 33, the method first proceeds to step 212, where the one or more controllers 33 terminate the executing haptic device operating mode if the haptic device operating mode is currently being executed. In response, the method proceeds to one of an autonomous check mode, a manual control mode, a simulated autonomous check mode, or a simulated manual control mode based on the selected haptic device operating mode. If the selected haptic device operating mode is already being executed, the method continues executing the selected haptic device operating mode. Thus, between steps 208 and 210, the one or more controllers 33 determine whether conditions prompt initiation of the haptic device operating mode or whether an operator commands initiation of the haptic device operating mode.

[0202] Thus, any haptic device operating mode can be initiated at any appropriate time in response to a condition or command. For example, in response to a condition or command, one or more controllers 33 can be configured to stop or pause autonomous control of the surgical tool 30 and then initiate a manual control mode to stop rotation of the pedicle screw PS (also shown in column F of FIG. 11A ). As another example, in response to a condition or command, one or more controllers 33 can be configured to initiate a manual control mode before autonomously controlling the surgical tool 30 (also shown in column F of FIG. 11A ). In such a case, one or more controllers 33 can switch from the manual control mode to stop or pause autonomous control of the surgical tool 30 and then resume autonomous control of the surgical tool to rotate the screw. In yet another example, in response to a condition or command, one or more controllers 33 can be configured to initiate a simulated autonomous check mode before or after stopping or pausing autonomous control of the surgical tool (also shown in column F of FIG. 11A ). In yet another example, in response to a condition or command, one or more controllers 33 may be configured to initiate a simulated manual control mode before or after stopping or pausing autonomous control of the surgical tool (also shown in column F of FIG. 11A).

[0203] The ability to initiate any haptic device operating mode at any appropriate time allows the operator to customize the surgery based on their preferences. For example, in one configuration in which the one or more controllers 33 stop or pause autonomously controlling the surgical tool 30 and then initiate manual control mode, the one or more controllers 33 can first autonomously insert the pedicle screw PS to an initial depth before the operator implants the pedicle screw PS to its final depth during manual control mode (or vice versa). In such a configuration, the pedicle screw PS can be autonomously placed until the pedicle screw PS is within a predetermined distance of the final depth (as determined by the navigation system 12). At this point, the operator can manually finish implanting the pedicle screw PS with the surgical tool 30 to allow the operator to more actively feel the tightening of the pedicle screw PS. The operator can also choose to complete the placement of the pedicle screw PS during manual control mode using a tool (powered or manual) different from that used during autonomous control.

[0204] Other configurations also illustrate the operator's ability to customize the surgery based on preferences. For example, in another configuration, one or more controllers 33 initiate a simulated autonomous check mode before autonomously controlling the surgical tool 30. In such a configuration, the operator can visualize a simulation of the autonomous control of the surgical tool 30 on the display 18 before the one or more controllers 33 initiate autonomous control to insert the pedicle screws PS. In another configuration, one or more controllers 33 initiate a simulated manual control mode before initiating a manual control mode to control the surgical tool 30. In such a configuration, the operator can visualize a simulation of the manual control of the surgical tool 30 on the display 18 before the one or more controllers 33 initiate manual control mode to manually control the insertion of the pedicle screws PS.

[0205] Furthermore, the ability to initiate any haptic device operating mode in response to a condition or command eliminates potential errors (e.g., collision with the spinal cord 103) and provides the operator with on-the-fly control of the procedure. For example, in the above configuration in which the one or more controllers 33 first autonomously insert the pedicle screw PS to an initial depth before the operator implants the pedicle screw PS to its final depth during manual control mode, the one or more controllers 33 can initiate the manual control mode in response to a condition or command. If a condition prompts the initiation of manual control mode and the cessation of autonomous control, the one or more controllers 33 can detect that the pedicle screw PS is within a predetermined distance of the final depth during autonomous control and send the condition to the one or more controllers 33. The one or more controllers 33 can then be prompted to initiate manual control mode and cessation of autonomous control, allowing the operator to manually complete the placement of the pedicle screw PS. The predetermined distance of the final depth can be predetermined so that the pedicle screw PS does not contact the spinal cord 103. When a command is issued to initiate the manual control mode, the operator may be instructed by the navigation system 12 regarding the state of autonomous control. For example, the display 18 may indicate how many rotations remain before the pedicle screw PS reaches maximum depth, and / or the display 18 may graphically represent the pedicle screw PS, the anatomy, and / or the target point so that the operator can easily visualize how much further insertion of the pedicle screw PS is required. The one or more controllers 33 may also provide tactile feedback (e.g., vibration or pulse) to the operator via the haptic device 51 to notify the operator that the pedicle screw PS has reached a predetermined depth. When the operator determines that the pedicle screw PS is within a predetermined distance of the final depth, the operator may instruct the one or more controllers 33 to initiate the manual control mode and stop autonomous control, allowing the operator to manually complete the placement of the pedicle screw PS.

[0206] Some exemplary conditions that may prompt initiation of the haptic device operating mode may include the pedicle screw PS reaching a desired depth, the pedicle screw PS potentially impinging on the spinal cord 103, and the pedicle screw PS being rotated a predetermined number of rotations. In such cases, the one or more controllers 33 may be configured to automatically select one of an autonomous check mode, a manual control mode, a simulated autonomous check mode, or a simulated manual control mode. In one such example, after the one or more controllers 33 autonomously control the surgical tool 30 to rotate the pedicle screw PS a predetermined number of rotations, the one or more controllers 33 may be configured to automatically select the manual control mode to allow the operator to manually complete the insertion of the pedicle screw PS.

[0207] The robotic surgical system 10 may include various components for commanding initiation of a haptic device operating mode. For example, an operator can use a haptic device 51 to command initiation of a haptic device operating mode. As shown in FIG. 10 , the haptic device 51 may include a user interface 57. The operator can select the haptic device operating mode using the user interface 57 by actuating the user interface 57 to send a command to one or more controllers 33. Alternatively, in some examples, the operator can select the haptic device operating mode by depressing the rotary interface 53. If the robotic surgical system 10 includes the surgical tool 30 of FIGS. 4-6 , the operator can select the haptic device operating mode using the trigger 49 or user interface 59 of the surgical tool 30. In other examples, the operator can select the haptic device operating mode via a user interface of the computer cart assembly 34, such as the keyboard 61 of the computer cart assembly 34. The operator can also select the haptic device operating mode via a user interface 63 of the base 22. It is contemplated that an individual other than the operator can command initiation of a haptic device operating mode. For example, initiation of the haptic device operating mode may be commanded by a remote user from a remote location using a remote user interface.

[0208] 15B illustrates exemplary steps of the autonomous check mode. As shown, the autonomous check mode includes step 304 of obtaining measurements indicative of the current interaction between the pedicle screw PS and the target site, and step 306 of controlling the actuator of the haptic device based on the obtained measurements to enable the rotational interface 53 of the haptic device 51 to emulate the current interaction between the pedicle screw PS and the target site, where the resistive force F A to the actuator 55 of the haptic device 51 to generate the force F required to rotate the rotation interface 53 by the operator's hand. RI, and adjusting the force F required to rotate the rotation interface 53. RI is the current force F required to rotate the pedicle screw PS relative to the target site. PS and step 306 reflecting the adjusted force F RI , and manually manipulate the rotation interface 53 according to the current force F required to rotate the pedicle screw PS relative to the target site without the ability to control the surgical tool 30. PS and providing 310 haptic feedback to the operator reflecting the

[0209] 15C illustrates exemplary steps of the manual control mode. As shown, the manual control mode includes step 300 of manually manipulating the rotation interface 53 with the ability to control one of the rotation speed of the pedicle screw PS or the advancement speed of the pedicle screw PS based on the operator manually manipulating the rotation interface 53; step 302 of controlling the surgical tool 30 to rotate the pedicle screw PS at a rotational speed about the rotation axis and linearly advance the pedicle screw PS at an advancement speed along a planned trajectory in response to the rotation interface being manually manipulated to control one of the rotation speed of the pedicle screw PS or the advancement speed of the pedicle screw PS; and steps 304, 306, and 308 described above, and adjusting the adjusted force F. RI The rotation interface 53 is manually operated according to the current force F required to rotate the pedicle screw PS relative to the target site. PS and providing 311 haptic feedback to the operator reflecting the

[0210] 15D illustrates exemplary steps of the simulated autonomous check mode. As shown, the simulated autonomous check mode includes step 312 of simulating autonomously controlling the surgical tool 30 by simulating rotating the pedicle screw PS at a rotational speed about the rotation axis R and simulating linearly advancing the screw at an advancement speed along the planned trajectory LH, step 314 of displaying the simulated autonomous control of the surgical tool 30 on the display 18, an example of step 304 of obtaining measurements indicative of a simulated current interaction between the pedicle screw PS and the target site (shown as step 304′), and an example of step 306 of controlling the actuator of the haptic device based on the obtained measurements to enable the rotational interface 53 of the haptic device 51 to emulate the simulated current interaction between the pedicle screw PS and the target site, where the resistance force F is applied. A to the actuator 55 to generate the force F required to manually rotate the rotation interface 53. RI (shown as step 308′) to adjust the force F required to rotate the rotation interface 53. RI is the current force F required to rotate the pedicle screw PS relative to the target site. SPS and an example of step 306 (shown as step 306′) reflecting the adjusted force F RI , without the ability to manually manipulate the rotation interface 53 to control the surgical tool 30 to rotate the pedicle screw PS, and without the ability to control the simulated autonomous control of the surgical tool 30, the simulated current force F SPS and providing 316 haptic feedback to the operator reflecting the

[0211] 15E illustrates exemplary steps of the simulated autonomous check mode. As shown, the simulated autonomous check mode includes step 318 of manually manipulating the rotation interface 53 without the ability to control the surgical tool 30 to rotate the pedicle screw PS, but with the ability to control one of the rotational speed of the pedicle screw PS or the advancement speed of the pedicle screw PS based on the operator manually manipulating the rotation interface 53; step 320 of simulating the manual control of the surgical tool 30 by rotating the pedicle screw PS at a rotational speed about the rotation axis R and linearly advancing the pedicle screw PS at an advancement speed along the planned trajectory LH in response to the rotational interface 53 being manually manipulated to control one of the rotational speed of the pedicle screw PS or the advancement speed of the pedicle screw PS; step 322 of displaying the simulated manual control of the surgical tool 30 on the display 18; step 304' as described above; step 306' as described above, including step 308' as described above; and step 320 of simulating the manual control of the surgical tool 30 by rotating the pedicle screw PS at a rotational speed about the rotation axis R and linearly advancing the pedicle screw PS at an advancement speed along the planned trajectory LH in response to the rotational interface 53 being manually manipulated to control one of the rotational speed of the pedicle screw PS or the advancement speed of the pedicle screw PS. RI , without the ability to manually manipulate the rotation interface 53 to control the surgical tool 30 to rotate the pedicle screw PS. SPS and providing 324 haptic feedback to the operator reflecting the

[0212] 15A , the dashed box indicates step 214 of autonomously controlling the surgical tool 30 to insert the pedicle screws PS. After step 202 of preparing the anatomy and step 204 of placing the pedicle screws PS on the surgical tool 30, step 214 may occur simultaneously with steps 206, 208, 210, and any of the autonomous check modes. As previously described, between the manual control mode, the simulated autonomous check mode, and the simulated manual control mode, the one or more controllers 33 are not autonomously controlling the surgical tool 30. Thus, upon entering any one of the manual control mode, the simulated autonomous check mode, or the simulated manual control mode, the one or more controllers 33 cease execution of step 214 and cease autonomous control of the surgical tool 30 (if the one or more controllers 33 are autonomously controlling the surgical tool 30). However, step 214 can be executed during any of steps 206, 208, 210, or at any time during the autonomous check mode, and one or more controllers 33 can simultaneously initiate autonomous control of the surgical tool 30.

[0213] Step 214 of autonomously controlling the surgical tool 30 is further illustrated in Figure 15F. As shown, the method includes step 400 of tracking the position of the target site, step 402 of positioning the rotation axis R along a desired trajectory, step 404 of controlling the movement of the robotic manipulator to maintain the rotation axis R of the surgical tool 30 along a planned trajectory LH relative to the target site based on the tracked position of the target site, and step 406 of autonomously controlling the surgical tool 30 to rotate the pedicle screw PS about the rotation axis R at a rotational rate and to linearly advance the pedicle screw PS at an advancement rate along the planned trajectory LH, where the rotational rate and advancement rate are predetermined and proportional to the known thread profile of the pedicle screw PS.

[0214] During step 400, the location of the target site is tracked. An ultrasound transducer (not shown) can be attached to the underside of the patient's skin to generate real-time images of the patient's anatomy and the progress of the surgical procedure. The intraoperative images can be used to determine whether the pedicle screws PS are following the desired planned trajectory or whether the drill 42 or pedicle screws PS are approaching any critical structures, including nerves and the medial or lateral cortical borders.

[0215] During step 402, the rotation axis R is aligned with the planned trajectory LH. As in FIG. 9 , if the rotation axis R is not yet aligned with the planned trajectory LH according to the surgical plan, or if the rotation axis R deviates from the desired trajectory for other reasons, the rotation axis R is aligned in step 402. Specifically, in step 402, the robotic surgical system 10 controls the movement of the surgical tool 30 to position the rotation axis R along the desired trajectory. This may include the robotic surgical system 10 causing autonomous movement of the surgical tool 30 to position the rotation axis R along the desired trajectory. Alternatively, the robotic surgical system 10 may allow the operator to move the surgical tool 30 by applying force / torque in manual mode until the rotation axis R is positioned along the planned trajectory LH. The robotic surgical system 10 may generate feedback (visual, audible, and / or tactile) to the operator indicating proper alignment. In some examples, the tool position is close to the planned trajectory LH by a threshold distance defined by the attractive haptics, and the attractive haptics can be used to pull the tool 30 toward the planned trajectory LH.

[0216] During step 406, the robotic surgical system 10 triggers the autonomous movement of the surgical tool 30, while simultaneously controlling the autonomous advancement of the tool in a straight line along the planned trajectory LH and the autonomous rotation of the surgical tool about the rotation axis R. The autonomous control of advancement and rotation is related to the thread pitch defined by Equation 1 above. The autonomous control, determined by the thread pitch, ensures proper insertion of the pedicle screw and avoids causing damage to the surrounding bone tissue.

[0217] Step 214 can be commanded by the operator in several ways. In a first example, the robotic surgical system 10 can be configured to execute fully autonomously. That is, once the operator commands the robotic surgical system 10 to perform autonomous control of the surgical tool 30, the robotic surgical system 10 executes autonomous control without further operator input until the operation is completed. In an alternative example, the operator can initiate the autonomous execution of the operation and then provide continuous input, such as by holding down a button, a footswitch, or other continuous input control, such that when the input stops, e.g., when the button or footswitch is released, the robotic surgical system 10 pauses execution of the operation. In conjunction with the autonomous control, the operator can adjust the speed at which the operation is executed. In addition to a button or footswitch, additional controls can be provided to allow the operator to command an increase or decrease in the robot's speed, in a stepwise function involving multiple discrete speeds. The additional speed control can include a set of buttons, selectors, dials, or other suitable controls.

[0218] Referring to FIG. 15A , during step 206, the robotic surgical system 10 determines whether the operation has ended. The operation may be determined to have ended using various methods. For example, if the operator determines that all pedicle screws PS have been implanted to the desired depth, the operator may command the end of the operation. As another example, if the operator subjectively determines that the operation has ended, the operator may command the end of the operation. As yet another example, if the one or more controllers 33 determine that all pedicle screws PS have been inserted to the desired depth, the one or more controllers 33 may trigger the end of the operation. However, in some examples, the operation is not ended after the pedicle screws PS have been implanted to the desired depth. In such cases, the method may continue by repeating the steps of the method of FIG. 15A for another pedicle screw PS until all pedicle screws PS have been implanted.

[0219] If the robotic surgical system 10 determines during step 206 that the operation is complete, the method proceeds to step 216, where it determines whether the surgical tool 30 has been inserted into the target site. During step 216, the one or more controllers 33 may determine the position of the surgical tool 30 and whether the surgical tool 30 has been inserted into the target site. If the robotic surgical system 10 determines that the surgical tool 30 has not been inserted, the method proceeds to step 218, which is the end of the operation. If the robotic surgical system 10 determines that the surgical tool 30 has been inserted, the method proceeds to step 220, where the tool is withdrawn before proceeding to the end of step 218.

[0220] During step 220, the surgical tool 30 is withdrawn from the implant. Similar to advancing the pedicle screw PS into the bone, the operator can input a force on the surgical tool 30 in a direction away from the vertebra V to command withdrawal of the surgical tool 30. Alternatively, the robotic surgical system 10 can autonomously withdraw the surgical tool 30 once the implant is placed without further input from the operator.

[0221] A partial facetectomy can be performed while the surgical tool 30 provides a smooth bone surface for the eventual reception of the head of the pedicle screw PS. The amount of resection can be defined based on the operator's plan, i.e., by determining the position of the head in a 3D model. A burr or pre-formed reamer 70 corresponding to the head shape can be used to remove material. In some cases, the drill 42 can incorporate a reamer to avoid a separate tool, such that the drill 42 includes a smaller-profile drilling shaft to create the pilot hole, and the drill 42 can be positioned more proximally to the reamer 70 to create the seat 72 for the head of the pedicle screw PS, thereby simultaneously forming at least a portion of the pilot hole 102 and the seat 72. In the example shown, the drill 42 includes a drilling shaft having proximal and distal ends and a drill tip at the distal end. The reamer 70 is spaced proximally from the drill tip so that when the drill 42 is inserted to the desired depth within the target vertebral body, the reamer 70 is located near the facet joint. The cutting function of any suitable drill and / or reamer can be used to form holes, such as pilot holes and seats in the patient's spine that will receive the implant.

[0222] It should be understood that the systems and methods described herein may be used to place pedicle screws PS, other screws, fasteners, or other implants in a patient. Thus, even though pedicle screws PS are referenced throughout as an example, the same systems and methods described herein may be utilized to treat any patient anatomical form and / or place any implant into a patient, for example, in the hip, knee, femur, tibia, face, shoulder, spine, etc. For example, the robotic arm 20 may also be used to place cages for spinal implants, place rods, drive pins, implant threaded cups, or place other components, and may be used for discectomy or other surgeries. For other surgeries, different end effectors may also be attached to the robotic arm 20. In some cases, the end effector may also include an articulated arm that facilitates implant insertion, i.e., positions the implant in a desired orientation. The articulated arm of the end effector may simply be a scaled-down version of the robotic arm 20, controlled in the same manner to place the implant, or may be a separate mechanism controlled to position the implant.

[0223] The navigation system 12 may include an optical navigation system with an optically based tracker, although other modalities may additionally or alternatively be used, such as an ultrasound navigation system that tracks objects via ultrasound, a radio frequency navigation system that tracks objects via RF energy, and / or an electromagnetic navigation system that tracks objects via electromagnetic signals. Other types of navigation systems are also contemplated. It should also be understood that in some cases, the models described herein may include triangular meshes, volumetric models using voxels, or other types of 3D and / or 2D models.

[0224] The foregoing description has set forth several examples. However, the examples discussed herein are not intended to be exhaustive or to limit the disclosure to any particular form. The terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teaching, and the disclosure may be practiced otherwise than as specifically described. In order to maintain the disclosure of the present application as originally filed, the contents of claims 1 to 46 as originally filed are added below. (Claim 1) A robot manipulator, a surgical tool coupled to the robotic manipulator and configured to engage a screw and rotate the screw about an axis of rotation; a haptic device including an actuator and a rotational interface coupled to the actuator, the rotational interface configured to be manually operable by an operator's hand; a navigation system configured to track the location of the target site; one or more controllers coupled to the robotic manipulator, the haptic device, and the navigation system; 1. A robotic surgery system comprising: The one or more controllers: controlling the motion of the robotic manipulator to maintain the axis of rotation of the surgical tool along a planned trajectory relative to the target site based on the tracked position of the target site; autonomously controlling the surgical tool to rotate the screw at a rotational speed about the rotation axis and to linearly advance the screw at an advancement speed along the planned trajectory, the rotational speed and the advancement speed being predefined and proportional to a known thread profile of the screw; obtaining a measurement indicative of a current interaction between the screw and the target site; controlling the actuator of the haptic device based on the acquired measurements to enable the rotational interface to emulate the current interaction between the screw and the target site; To do Robotic surgery system. (Claim 2) 10. The robotic surgical system of claim 1, wherein the one or more controllers are configured to provide a resistance force to the actuator to adjust the force required to rotate the rotation interface by the operator's hand, thereby further emulating the current interaction between the screw and the target site, wherein the force required to rotate the rotation interface reflects the current force needed to rotate the screw relative to the target site. (Claim 3) 3. The robotic surgical system of claim 2, wherein the one or more controllers are further configured to initiate an autonomous check mode, and wherein the rotation interface is manually operable without the ability to control the surgical tool to rotate the screw to provide haptic feedback to the operator reflecting the current force required to rotate the screw relative to the target site according to the adjusted force. (Claim 4) 4. The robotic surgical system of claim 3, wherein the one or more controllers are further configured to initiate the autonomous check mode simultaneously with autonomously controlling the surgical tool in response to a condition or command. (Claim 5) 5. The robotic surgical system of claim 3 or 4, further configured to, in response to a condition or command, the one or more controllers stop or pause autonomously controlling the surgical tool to stop rotating the screw and then initiate the autonomous check mode. (Claim 6) 6. The robotic surgical system of claim 3, wherein, in response to a condition or command, the one or more controllers are further configured to: stop or pause autonomous control of the surgical tool to stop rotating the screw, and then resume autonomous control of the surgical tool to rotate the screw. (Claim 7) the one or more controllers are further configured to initiate a manual control mode, wherein the rotational interface is manually operable with the ability to control one of the rotational speed of the screw or the advancement speed of the screw based on the operator manually manipulating the rotational interface; the one or more controllers are configured to control the surgical tool to rotate the screw at the rotational speed about the rotation axis and to linearly advance the screw at the advancement speed along the planned trajectory in response to the rotation interface being manually manipulated to control one of the rotational speed of the screw or the advancement speed of the screw; the rotation interface is manually operable according to the adjusted force and provides the operator with tactile feedback reflecting the current force required to rotate the screw relative to the target site. 7. The robotic surgery system according to claim 2. (Claim 8) 8. The robotic surgical system of claim 7, further configured to, in response to a condition or command, the one or more controllers stop or pause autonomously controlling the surgical tool to stop rotating the screw and then initiate the manual control mode. (Claim 9) 10. The robotic surgical system of claim 8, wherein, in response to a condition or command, the one or more controllers are further configured to switch from the manual control mode to resume autonomously controlling the surgical tool to rotate the screw. (Claim 10) The robotic surgery system of claim 4 , wherein the haptic device is configured to trigger the condition or the command. (Claim 11) 11. The robotic surgical system of claim 1, further comprising a sensor configured to obtain the measurement indicative of the current interaction between the screw and the target site, the one or more controllers coupled to the sensor. (Claim 12) the one or more controllers: determining that a condition exists in control of the screw; In response to determining that the condition exists, providing haptic feedback to the operator regarding the condition by interfering with the ability to control the actuator of the haptic device to rotate the rotational interface. 12. The robotic surgery system according to claim 7, wherein the robotic surgery system is configured as follows. (Claim 13) The navigation system determining a position of the screw relative to an anatomical model of the target site registered to the target site, the navigation system including predetermined data indicative of an expected interaction between the screw and the anatomical model at a plurality of positions of the screw relative to the anatomical model; obtaining the measurements indicative of the current interaction between the screw and the target site based on the determined position of the screw relative to the anatomical model and the predetermined data; 13. The robotic surgery system according to claim 1, further configured to perform the following: (Claim 14) The rotational speed and the forward speed are related

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Claims

1. A robot manipulator, a surgical tool coupled to the robotic manipulator and configured to engage a screw and rotate the screw about an axis of rotation; a haptic device including an actuator and a rotational interface coupled to the actuator, the rotational interface configured to be manually operable by an operator's hand; a navigation system configured to track the location of the target site; one or more controllers coupled to the robotic manipulator, the haptic device, and the navigation system; 1. A robotic surgery system comprising: The one or more controllers: controlling the motion of the robotic manipulator to maintain the axis of rotation of the surgical tool along a planned trajectory relative to the target site based on the tracked position of the target site; autonomously controlling the surgical tool to rotate the screw at a rotational speed about the rotation axis and linearly advance the screw at an advancement speed along the planned trajectory, wherein the rotational speed and the advancement speed are predefined, the rotational speed being proportional to a pitch, which is the number of threads per unit length of the screw, and the advancement speed being inversely proportional to the pitch, which is the number of threads per unit length of the screw; obtaining a measurement indicative of a current interaction between the screw and the target site; controlling the actuator of the haptic device based on the acquired measurements to enable the rotational interface to emulate the current interaction of rotation between the screw and the target site. and Robotic surgery system.

2. 2. The robotic surgical system of claim 1, wherein the one or more controllers are configured to provide a resistance force to the actuator to adjust the force required to rotate the rotation interface by the operator's hand, thereby further emulating the current interaction between the screw and the target site, wherein the force required to rotate the rotation interface reflects the current force needed to rotate the screw relative to the target site.

3. 3. The robotic surgical system of claim 2, wherein the one or more controllers are further configured to initiate an autonomous check mode for autonomous control of the surgical tool before, during, or after autonomous control of the surgical tool, and wherein when the one or more controllers initiate the autonomous check mode, the rotation interface is manually operable without the ability to control the surgical tool to rotate the screw to provide the operator with haptic feedback reflecting the current force required to rotate the screw relative to the target site in accordance with the adjusted force.

4. The robotic surgical system of claim 3 , wherein the one or more controllers are further configured to initiate the autonomous check mode simultaneously with autonomously controlling the surgical tool in response to a condition or command.

5. 5. The robotic surgical system of claim 3 or 4, further configured to, in response to a condition or command, the one or more controllers stop or pause autonomously controlling the surgical tool to stop rotating the screw and then initiate the autonomous check mode.

6. 6. The robotic surgical system of claim 3, wherein, in response to a condition or command, the one or more controllers are further configured to: stop or pause autonomous control of the surgical tool to stop rotating the screw, and then resume autonomously controlling the surgical tool to rotate the screw.

7. the one or more controllers are further configured to initiate a manual control mode, wherein the rotational interface is manually operable with the ability to control one of the rotational speed of the screw or the advancement speed of the screw based on the operator manually manipulating the rotational interface; the one or more controllers are configured to control the surgical tool to rotate the screw at the rotational speed about the rotation axis and to linearly advance the screw at the advancement speed along the planned trajectory in response to the rotation interface being manually manipulated to control one of the rotational speed of the screw or the advancement speed of the screw; the rotation interface is manually operable according to the adjusted force and provides the operator with tactile feedback reflecting the current force required to rotate the screw relative to the target site. The robotic surgery system according to any one of claims 2 to 6.

8. 8. The robotic surgical system of claim 7, further configured to, upon a condition or command, the one or more controllers stop or pause autonomously controlling the surgical tool to stop rotating the screw and then initiate the manual control mode.

9. 10. The robotic surgical system of claim 8, wherein, in response to a condition or command, the one or more controllers are further configured to switch from the manual control mode to resume autonomously controlling the surgical tool to rotate the screw.

10. The robotic surgery system of any one of claims 4 to 9, wherein the haptic device is configured to trigger the condition or the command.

11. 11. The robotic surgery system of claim 1, further comprising a sensor configured to obtain the measurement indicative of the current interaction between the screw and the target site, the one or more controllers coupled to the sensor.

12. the one or more controllers: identifying a condition that prevents rotation of the rotational interface while controlling the screw; In response to identifying the condition, providing haptic feedback to the operator regarding the condition by interfering with the ability to control the actuator of the haptic device to rotate the rotational interface. The robotic surgery system according to any one of claims 7 to 11, configured as follows:

13. The navigation system determining a position of the screw relative to an anatomical model of the target site to which the target site is registered; obtaining the measurements indicative of the current interaction between the screw and the target site based on the determined position of the screw relative to the anatomical model and predetermined data indicative of an expected interaction between the screw and the anatomical model at the determined position of the screw relative to the anatomical model; The robotic surgery system of any one of claims 1 to 12, further configured to:

14. The rotational speed and the forward speed are related [Equation 1] where: [Equation 2] is the rotational speed, [Equation 3] 14. The robotic surgery system of claim 1, wherein: is the advancement speed and pitch is the number of threads per unit length of the screw.

15. The robotic surgery system of any one of claims 1 to 14, wherein the haptic device is further defined as a handheld pendant and the rotary interface is further defined as a knob.

16. The one or more controllers receive input from the operator; the resistive force provided to the actuator; and the sensitivity with which the rotation interface controls the surgical tool to rotate the screw; The robotic surgical system of claim 2 , further configured to selectively adjust one or more of:

17. the robotic surgical system further includes a display, and the one or more controllers are further configured to initiate a simulated autonomous check mode before, during, or after the simulated autonomous insertion of the screw by the robotic surgical system, simulating autonomous control of the surgical tool; When the one or more controllers initiate the simulated autonomous check mode, autonomously controlling the surgical tool by simulating rotation of the screw at the rotational speed about the rotation axis and simulating linear advancement of the screw at the advancement speed along the planned trajectory; displaying the simulated autonomous control of the surgical tool on the display; obtaining a simulated current interaction between the screw and the target site; Controlling the actuator of the haptic device based on the simulated current interaction to enable the rotational interface to emulate the simulated current interaction between the screw and the target site. The robotic surgery system according to any one of claims 1 to 16, configured as follows:

18. 18. The robotic surgical system of claim 17, wherein the one or more controllers are further configured to initiate the simulated autonomous check mode before autonomously controlling the surgical tool.

19. the robotic surgical system further includes a display, and the one or more controllers are further configured to initiate a simulated manual control mode; The one or more controllers: receiving a control input in response to the rotation interface being manually operated to control one of the rotational speed of the screw or the advancement speed of the screw; manually controlling the surgical tool by simulating rotation of the screw at the rotational speed about the rotation axis and simulating linear advancement of the screw at the advancement speed along the planned trajectory in response to the control input; displaying the simulated manual control of the surgical tool on the display; obtaining a simulated current interaction between the screw and the target site; Controlling the actuator of the haptic device based on the simulated current interaction to enable the rotational interface to emulate the simulated current interaction between the screw and the target site. The robotic surgery system according to any one of claims 1 to 18, configured as follows:

20. 20. The robotic surgical system of claim 19, further configured to, upon a condition or command, the one or more controllers stop or pause autonomously controlling the surgical tool to stop rotating the screw and then initiate the simulated manual control mode.

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