Methods for identifying and segmenting anatomical structures from cone-beam CT images

Abstract

A method for identifying and segmenting anatomical structures from cone beam CT images is disclosed. An image processing system receives at least one 2D x-ray image from a cone beam CT device, which is a portion of a set of x-ray images acquired from a 360 degree scan of a patient using a cone beam CT imaging device. The x-ray image contains at least one anatomical structure, such as a vertebral body to be segmented. The received x-rays are then analyzed to identify and segment the anatomical structure contained in the x-ray image based on a stored anatomical structure model. Once the 360 ​​degree rotation is completed, a 3D image volume from the set of x-ray images is created. The identification and segmentation information derived from the x-ray image is then added to the created 3D image volume.

Description

Technical Field

[0001] The present invention relates to surgical imaging systems and, in particular, to systems for automatically segmenting anatomical structures. Background Art

[0002] Automatic segmentation of a two-dimensional (2D) image or a three-dimensional (3D) image volume refers to the process of automatically delineating boundaries between adjacent structures and optionally correctly identifying each structure. For example, successful automatic segmentation of a previously unreviewed spinal x-ray image means that each vertebra or vertebral body in the image is automatically highlighted or outlined, and each vertebra is automatically or semi-automatically correctly identified ("L2", "L3", etc.).

[0003] There are methods that use deep learning or neural networks to train computer models to identify structures within an image plane or volume by comparing a new image to a set of known images. Because scanning an image volume is computationally more complex than scanning a 2D image plane, the process of automatically segmenting a 3D image volume, such as a computed tomography (CT) scan, can be slower than the process of automatically segmenting a simple 2D x-ray. Furthermore, the accuracy of 3D image segmentation can depend on seeding the software starting point through user input.

[0004] In contrast, segmentation software used to identify structures in 2D image planes (such as vertebral levels in a 2D x-ray image of the spinal region) is faster and less dependent on seeding, but is often not as reliable as corresponding 3D segmentation software because less information is present in the 2D image.

[0005] Therefore, there is a need for a system and method that combines the speed of 2D segmentation with the accuracy of 3D segmentation. Summary of the invention

[0006] According to one aspect of the present invention, a method for identifying and segmenting anatomical structures from cone beam CT images is disclosed. An image processing system receives at least one x-ray image from a cone beam CT device, which is a portion of a set of x-ray images acquired from a 360 degree scan of a patient using a cone beam CT imaging device. The x-ray image contains at least one anatomical structure to be segmented. The received x-rays are then analyzed to identify and segment at least one anatomical structure contained in the x-ray image based on a stored anatomical structure model. Once the 360 ​​degree rotation is completed, a 3D image volume from the set of x-ray images is created. The identification and segmentation information derived from the x-ray image is then added to the created 3D image volume.

[0007] Advantageously, segmentation and identification are performed from 2D x-ray images rather than from 3D image volumes. Since 2D x-ray images are available while the imaging system is rotating, processing can begin before the rotation is complete. Furthermore, image processing of 2D images can be much faster than 3D volumes. Thus, the method of the present invention can save a great deal of time while being very accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a top view of a possible arrangement of the positions of the robotic system, patient, surgeon, and other medical personnel during a surgical procedure;

[0009] Figure 2 A robotic system including a surgical robot and positioning of a camera relative to a patient is shown according to one embodiment;

[0010] Figure 3 A surgical robotic system according to an exemplary embodiment is illustrated;

[0011] Figure 4 illustrates portions of a surgical robot according to an exemplary embodiment;

[0012] Figure 5 illustrates a block diagram of a surgical robot according to an exemplary embodiment;

[0013] Figure 6 A surgical robot according to an exemplary embodiment is shown;

[0014] 7A to 7C An end effector according to an exemplary embodiment is shown;

[0015] Figure 8 shows a surgical instrument and an end effector before and after inserting the surgical instrument into a guide tube of the end effector according to one embodiment;

[0016] 9A to 9C shows portions of an end effector and a robotic arm according to an exemplary embodiment;

[0017] Fig.10 shows a dynamic reference array, imaging array, and other components according to an exemplary embodiment;

[0018] Fig.11 A registration method according to an exemplary embodiment is shown;

[0019] FIG. 12A to FIG. 12B An embodiment of an imaging device according to an exemplary embodiment is shown;

[0020] Fig.13A shows a portion of a robot including a robot arm and an end effector according to an exemplary embodiment;

[0021] Fig. 13B yes Fig.13A a close-up view of an end effector shown having a plurality of tracking markers rigidly attached thereto;

[0022] Fig. 13C is a tool or instrument having a plurality of tracking markers rigidly attached thereto according to one embodiment;

[0023] Fig.14A is an alternative version of the end effector having a movable tracking marker in the first configuration;

[0024] Fig. 14B is in the second configuration with a removable tracking mark Fig.14A The end effector shown in ;

[0025] Fig. 14C Shown from Fig.14A a template for tracking markers in a first configuration;

[0026] Fig.14D Shown from Fig. 14B A template for tracking markers in a second configuration;

[0027] Fig.15A An alternative version of the end effector is shown with only a single tracking marker attached;

[0028] Fig. 15B A device having a catheter placed therethrough is shown. Fig.15A The end effector;

[0029] Fig. 15C Shows Fig.15A an end effector having an instrument in two different positions and resulting logic to determine whether the instrument is positioned within or outside of the catheter;

[0030] Fig.15D shows an apparatus in a catheter with two different frames Fig.15A an end effector, and a relative distance of the end effector from a single tracking marker on the catheter;

[0031] Fig.15E Shows the coordinate system relative to Fig.15A The end effector;

[0032] Fig.16 is a block diagram of a method for navigating and moving an end effector of a robot to a desired target trajectory;

[0033] Figures 17A-17B depicts an apparatus for inserting an expandable implant having fixed and removable tracking markers in collapsed and expanded positions, respectively;

[0034] Figures 18A-18B depicts instruments for inserting an articulated implant having fixed and movable tracking markers in insertion and tilted positions, respectively;

[0035] Fig.19A and 19B Typical AP and lateral images of the spine are shown;

[0036] Fig. 20 showing a misaligned transverse image of the spine;

[0037] Fig.21 A method for determining a 3-dimensional position of an imaging arm of an imaging device for capturing an optimal image of a vertebral body according to one aspect of the present invention is shown;

[0038] Fig. 22 A calibration ring with tracking marks according to an aspect of the present invention is shown;

[0039] Fig.23 is an example of an x-ray imaging apparatus according to an aspect of the present invention, which is capable of automatic positioning with respect to the 3D position and orientation of its C-arm;

[0040] Fig.24A is an example of a graphical user interface showing available selections of images at different spinal segments according to aspects of the invention;

[0041] Fig. 24B is an example of a graphical user interface showing additional available selections of images at adjacent spinal segments according to aspects of the invention;

[0042] Fig.25 is an example of a graphical user interface for guiding a user to position a C-arm in an optimal position according to aspects of the present invention;

[0043] Fig.26 is a representation of a method of segmenting a vertebral body according to aspects of the present invention;

[0044] Fig.27A and 27B graphically illustrating a method of aligning a 3D model of a selected vertebral body with scanned AP and transverse images according to aspects of the present invention;

[0045] Fig.28 is a flow chart of image control software for automatic segmentation and calculation of data associated with a 3D rotated 3D image volume of an imaging system according to aspects of the present invention;

[0046] Fig.29A a conventional graphical display showing the output of the 3D image volume; and

[0047] Fig.29B A graphical display of the output of a 3D image volume with superimposed automatic segmentation information according to aspects of the present invention is shown. DETAILED DESCRIPTION

[0048] It should be understood that the present disclosure is not limited in its application to the details of the construction and arrangement of the components set forth in the description herein or illustrated in the accompanying drawings. The teachings of the present disclosure may be used and practiced in other embodiments, and practiced or implemented in various ways. Also, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered restrictive. The use of "includes," "comprising," or "having" and their variations herein is intended to cover the items listed thereafter and their equivalents and additional items. Unless otherwise specified or limited, the terms "install," "connect," "support," and "couple" and their variations are widely used and cover both direct and indirect installations, connections, supports, and couplings. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings.

[0049] The following discussion is presented to enable those skilled in the art to make and use embodiments of the present disclosure. Those skilled in the art will readily appreciate various modifications to the illustrated embodiments, and without departing from the embodiments of the present disclosure, the principles herein may be applied to other embodiments and applications. Therefore, the embodiments are not intended to be limited to the embodiments shown, but should be given the widest scope consistent with the principles and features disclosed herein. The following detailed description should be read with reference to the accompanying drawings, in which similar elements in different figures have similar reference numerals. The figures, which are not necessarily to scale, depict the selected embodiments and are not intended to limit the scope of the embodiments. Those skilled in the art will recognize that the embodiments provided herein have many useful alternatives and fall within the scope of the embodiments.

[0050] Now turning to the accompanying drawings, Figure 1 and Figure 2A surgical robotic system 100 is shown according to an exemplary embodiment. The surgical robotic system 100 may include, for example, a surgical robot 102, one or more robotic arms 104, a base 106, a display 110, an end effector 112 including, for example, a guide tube 114, and one or more tracking markers 118. The surgical robotic system 100 may include a patient tracking device 116, which also includes one or more tracking markers 118, and the patient tracking device is suitable for being directly fixed to a patient 210 (e.g., fixed to a bone of the patient 210). The surgical robotic system 100 may also utilize, for example, a camera 200 positioned on a camera support 202. The camera support 202 may have any suitable configuration to move, orient, and support the camera 200 in a desired position. The camera 200 may include any suitable one or more cameras capable of identifying, for example, active and passive tracking markers 118 in a given measurement volume visible from the perspective of the camera 200, such as one or more infrared cameras (e.g., dual focus or stereo photogrammetry cameras). The camera 200 can scan a given measurement volume and detect light from the markers 118 to identify and determine the location of the markers 118 in three dimensions. For example, active markers 118 can include infrared emitting markers activated by electrical signals (e.g., infrared light emitting diodes (LEDs)), and passive markers 118 can include retroreflective markers that reflect infrared light (e.g., they reflect incoming IR radiation into the direction of the incident light), such as emitted by an illuminator on the camera 200 or other suitable device.

[0051] Figure 1 and 2 A potential configuration for placement of the surgical robotic system 100 in an operating room environment is shown. For example, the robot 102 can be located near or beside the patient 210. Although depicted near the head of the patient 210, it should be understood that the robot 102 can be located in any suitable location near the patient 210, depending on the area of ​​the patient 210 being operated on. The camera 200 can be separate from the robotic system 100 and positioned at the foot of the patient 210. The position allows the camera 200 to have a direct line of sight to the surgical field of view 208. Again, it is contemplated that the camera 200 can be located in any suitable location with a line of sight to the surgical field of view 208. In the configuration shown, the surgeon 120 can be positioned opposite the robot 102, but still be able to manipulate the end effector 112 and the display 110. The surgical assistant 126 can again be positioned opposite the surgeon 120 and can access both the end effector 112 and the display 110. If desired, the positions of the surgeon 120 and the assistant 126 can be reversed. The traditional area for the anesthesiologist 122 and nurse or surgical technician 124 remains unobstructed by the position of the robot 102 and camera 200.

[0052] With respect to other components of the robot 102, the display 110 may be attached to the surgical robot 102, and in other exemplary embodiments, the display 110 may be separate from the surgical robot 102, whether in an operating room with the surgical robot 102 or at a remote location. The end effector 112 may be coupled to the robot arm 104 and controlled by at least one motor. In an exemplary embodiment, the end effector 112 may include a guide tube 114 that is capable of receiving and directing a surgical instrument 608 (described further herein) for performing a surgical procedure on a patient 210. As used herein, the term "end effector" is used interchangeably with the terms "end implementer" and "implementer element". Although typically shown with a guide tube 114, it should be understood that the end effector 112 may be replaced with any suitable instrument suitable for surgical procedures. In some embodiments, the end effector 112 may include any known structure for achieving movement of the surgical instrument 608 in a desired manner.

[0053] The surgical robot 102 is capable of controlling the translation and orientation of the end effector 112. The robot 102 is capable of moving the end effector 112, for example, along the x-axis, y-axis, and z-axis. The end effector 112 can be configured for selective rotation about one or more of the x-axis, y-axis, and z-axis and the Z-frame axis (so that one or more Euler angles (e.g., roll, pitch, and / or yaw) associated with the end effector 112 can be selectively controlled). In some exemplary embodiments, the selective control of the translation and orientation of the end effector 112 can allow the performance of medical procedures with significantly improved accuracy compared to conventional robots utilizing, for example, a six-degree-of-freedom robotic arm that includes only a rotation axis. For example, the surgical robotic system 100 can be used to operate on a patient 210, and the robotic arm 104 can be positioned above the body of the patient 210, with the end effector 112 selectively angled toward the body of the patient 210 relative to the z-axis.

[0054] In some exemplary embodiments, the position of the surgical instrument 608 can be dynamically updated so that the surgical robot 102 can always know the position of the surgical instrument 608 during surgery. Therefore, in some exemplary embodiments, the surgical robot 102 can quickly move the surgical instrument 608 to the desired position without any further assistance from the physician (unless the physician needs it). In some further embodiments, the surgical robot 102 can be configured to correct the path of the surgical instrument 608 if the surgical instrument 608 deviates from the selected pre-planned trajectory. In some exemplary embodiments, the surgical robot 102 can be configured to allow the movement of the end effector 112 and / or the surgical instrument 608 to be stopped, modified and / or manually controlled. Therefore, in an exemplary embodiment, in use, a physician or other user can operate the system 100 and can choose to stop, modify or manually control the autonomous movement of the end effector 112 and / or the surgical instrument 608. Further details of the surgical robot system 100 including the control and movement of the surgical instrument 608 by the surgical robot 102 can be found in the co-pending U.S. patent application No. 13 / 924,505, the entire contents of which are incorporated herein by reference.

[0055] The robotic surgical system 100 may include one or more tracking markers 118 configured to three-dimensionally track the movement of the robotic arm 104, the end effector 112, the patient 210, and / or the surgical instrument 608. In an exemplary embodiment, a plurality of tracking markers 118 may be mounted (or otherwise affixed) to an external surface of the robot 102, such as (and not limited to) the base 106 of the robot 102, the robotic arm 104, or the end effector 112. In an exemplary embodiment, at least one tracking marker 118 of the plurality of tracking markers 118 may be mounted or otherwise affixed to the end effector 112. One or more tracking markers 118 may further be mounted (or otherwise affixed) to the patient 210. In an exemplary embodiment, the plurality of tracking markers 118 may be positioned on the patient 210 spaced apart from the surgical field of view 208 to reduce the possibility of being obstructed by the surgeon, surgical tools, or other parts of the robot 102. In addition, one or more tracking markers 118 may be further mounted (or otherwise secured) to a surgical tool 608 (e.g., a screwdriver, dilator, implant inserter, etc.). Thus, the tracking markers 118 enable each of the marked objects (e.g., the end effector 112, the patient 210, and the surgical tool 608) to be tracked by the robot 102. In an exemplary embodiment, the system 100 may use the tracking information collected from each marked object to calculate, for example, the orientation and position of the end effector 112, the surgical instrument 608 (e.g., positioned in the tube 114 of the end effector 112), and the relative position 210 of the patient.

[0056] In an exemplary embodiment, one or more of the markers 118 may be optical markers. In some embodiments, the positioning of one or more tracking markers 118 on the end effector 112 may maximize the accuracy of position measurement by being used to check or verify the position of the end effector 112. Further details of the surgical robotic system 100 including control, movement, and tracking of the surgical robot 102 and surgical instruments 608 may be found in co-pending U.S. Patent Application No. 13 / 924,505, the entire contents of which are incorporated herein by reference.

[0057] The exemplary embodiment includes one or more markers 118 coupled to the surgical instrument 608. In the exemplary embodiment, for example, these markers 118 coupled to the patient 210 and the surgical instrument 608, as well as the markers 118 coupled to the end effector 112 of the robot 102 may include conventional infrared light emitting diodes (LEDs) or may be capable of being tracked using a commercially available infrared optical tracking system (e.g., )Tracking diode. is a registered trademark of Northern Digital Inc. of Waterloo, Ontario, Canada. In other embodiments, the marker 118 may include a conventional reflective sphere that can be tracked using a commercially available optical tracking system (e.g., Polaris Spectra). Polaris Spectra is also a registered trademark of Northern Digital. In an exemplary embodiment, the marker 118 coupled to the end effector 112 is an active marker that includes an infrared light emitting diode that can be turned on and off, and the marker 118 coupled to the patient 210 and the surgical instrument 608 includes a passive reflective sphere.

[0058] In an exemplary embodiment, light emitted and / or reflected by the marker 118 can be detected by the camera 200 and can be used to monitor the position and movement of the tagged object. In alternative embodiments, the marker 118 can include a radio frequency and / or electromagnetic reflector or transceiver, and the camera 200 can include or be replaced by a radio frequency and / or electromagnetic transceiver.

[0059] Similar to the surgical robot system 100, Figure 3 A surgical robot system 300 and a camera support 302 are shown in a docked configuration consistent with an exemplary embodiment of the present disclosure. The surgical robot system 300 may include a robot 301 including a display 304, an upper arm 306, a lower arm 308, an end effector 310, a vertical column 312, casters 314, a cabinet 316, a flat drawer 318, a connector panel 320, a control panel 322, and an information ring 324. The camera support 302 may include a camera 326. These components are referred to as Figure 5 Describe in more detail. Figure 3 The surgical robotic system 300 is shown in a docked configuration, with the camera support 302 nested with the robot 301, for example when not in use. Those skilled in the art will recognize that the camera 326 and the robot 301 can be separated from each other during a surgical procedure and positioned in any suitable position, such as Figure 1 and 2 shown.

[0060] Figure 4 A base 400 consistent with an exemplary embodiment of the present disclosure is shown. The base 400 may be part of the surgical robot system 300 and include a cabinet 316. The cabinet 316 may house certain components of the surgical robot system 300, including but not limited to a battery 402, a power distribution module 404, a platform interface board module 406, a computer 408, a handle 412, and a flat panel drawer 414. The connections and relationships between these components refer to Figure 5 Describe in more detail.

[0061] Figure 5 A block diagram of certain components of an exemplary embodiment of a surgical robot system 300 is shown. The surgical robot system 300 may include a platform subsystem 502, a computer subsystem 504, a motion control subsystem 506, and a tracking subsystem 532. The platform subsystem 502 may further include a battery 402, a power distribution module 404, a platform interface board module 406, and a tablet charging station 534. The computer subsystem 504 may further include a computer 408, a display 304, and a speaker 536. The motion control subsystem 506 may further include a driver circuit 508, motors 510, 512, 514, 516, 518, stabilizers 520, 522, 524, 526, an end effector 310, and a controller 538. The tracking subsystem 532 may further include a position sensor 540 and a camera converter 542. The system 300 may also include a foot pedal 544 and a tablet 546.

[0062] Input power is supplied to the system 300 via a power supply 548 that may be provided to the power distribution module 404. The power distribution module 404 receives the input power and is configured to generate different supply voltages that are provided to other modules, components, and subsystems of the system 300. The power distribution module 404 may be configured to provide different voltage supplies to the platform interface module 406 that may be provided to other components such as the computer 408, the display 304, the speaker 536, the drive 508, etc., to power, for example, the motors 512, 514, 516, 518 and the end effector 310, the motor 510, the ring 324, the camera converter 542, and other components for the system 300, such as fans for cooling electrical components within the cabinet 316.

[0063] The power distribution module 404 may also provide power to other components, such as a tablet charging station 534 that may be located within the tablet drawer 318. The tablet charging station 534 may communicate wirelessly or wired with the tablet 546 for charging the tablet 546. The tablet 546 may be used by a surgeon consistent with the present disclosure and as described herein.

[0064] The power distribution module 404 may also be connected to the battery 402, which serves as a temporary power source in the event that the power distribution module 404 is not receiving power from the input power 548. At other times, the power distribution module 404 may be used to charge the battery 402 if necessary.

[0065] Other components of the platform subsystem 502 may also include a connector panel 320, a control panel 322, and a ring 324. The connector panel 320 may be used to connect different devices and components to the system 300 and / or associated components and modules. The connector panel 320 may include one or more ports that receive wires or connections from different components. For example, the connector panel 320 may have a ground terminal port that can ground the system 300 to other equipment, a port that connects the foot pedal 544 to the system 300, and a port that connects to the tracking subsystem 532, which may include a position sensor 540, a camera converter 542, and a camera 326 associated with the camera support 302. [The ports in the connector panel 320 may also be connected to an imaging device for receiving scanned images and controlling the position and orientation of the C-arm based on optical / navigation markers attached to the imaging device] The connector panel 320 may also include other ports for allowing USB, Ethernet, HDMI to communicate with other components such as the computer 408.

[0066] The control panel 322 may provide various buttons or indicators for controlling the operation of the system 300 and / or providing information about the system 300. For example, the control panel 322 may include buttons for powering the system 300 on or off, raising or lowering the vertical column 312, and raising or lowering the stabilizers 520-526, which may be designed to engage the casters 314 to lock the system 300 from physical movement. Other buttons may stop the system 300 in an emergency, which may remove all motor power and apply mechanical brakes to prevent all movement from occurring. The control panel 322 may also have indicators for notifying the user of certain system conditions, such as a line power indicator or the charge status of the battery 402.

[0067] Ring 324 may be a visual indicator to inform a user of system 300 of the different modes in which system 300 is operating as well as certain warnings to the user.

[0068] The computer subsystem 504 includes a computer 408, a display 304, and a speaker 536. The computer 504 includes an operating system and software for operating the operating system 300. The computer 504 can receive and process information from other components (e.g., the tracking subsystem 532, the platform subsystem 502, and / or the motion control subsystem 506) to display information to the user. In addition, the computer subsystem 504 may also include a speaker 536 to provide audio to the user.

[0069] Tracking subsystem 532 may include position sensor 504 and transducer 542. Tracking subsystem 532 may correspond to camera support 302 including camera 326, as shown in FIG. Figure 3 The position sensor 504 may be a camera 326. The tracking subsystem may track the position of certain markers located on different components of the system 300 and / or on instruments used by a user during a surgical procedure. This tracking may be performed in a manner consistent with the present disclosure, including the use of infrared technology that tracks the position of active or passive elements such as LEDs or reflective markers, respectively. The location, orientation, and position of structures having these types of markers may be provided to the computer 408 and may be presented to the user on the display 304. For example, a surgical instrument 608 having these types of markers and tracked in this manner (which may be referred to as a navigation space) may present a three-dimensional image of the associated patient's anatomical structure to the user.

[0070] The motion control subsystem 506 can be configured to physically move the vertical column 312, the upper arm 306, the lower arm 308, or the rotary end effector 310. The physical movement can be performed by using one or more motors 510-518. For example, the motor 510 can be configured to vertically raise or lower the vertical column 312. Figure 3 As shown, the motor 512 can be configured to move the upper arm 308 laterally about the point of engagement with the vertical column 312. Figure 3 As shown, motor 514 can be configured to move lower arm 308 laterally about a point of engagement with upper arm 308. Motors 516 and 518 can be configured to move end effector 310 in a controllable tilt and controllable tilt manner, thereby providing a plurality of angles at which end effector 310 can be moved. These movements can be achieved by controller 538, which can control these movements through load cells that are disposed on end effector 310 and activated by a user engaging these load cells to move system 300 in a desired manner.

[0071] In addition, system 300 can provide for automatic movement of vertical column 312, upper arm 306, and lower arm 308 by the user indicating on display 304 (which can be a touch screen input device) the position of surgical instruments or assemblies on a three-dimensional image of the patient's anatomy on display 304. The user can initiate this automatic movement by stepping on foot pedal 544 or some other input device.

[0072] Figure 6 A surgical robotic system 600 consistent with an exemplary embodiment is shown. The surgical robotic system 600 may include an end effector 602, a robotic arm 604, a guide tube 606, an instrument 608, and a robotic base 610. The instrument tool 608 may be attached to a tracking array 612 containing one or more tracking markers (e.g., marker 118) and have an associated trajectory 614. The trajectory 614 may represent a movement path that the instrument tool 608 is configured to travel once it passes through or is secured in the guide tube 606, such as a path that the instrument tool 608 is inserted into a patient's body. In exemplary operation, the robotic base 610 may be configured to electronically communicate with the robotic arm 604 and the end effector 602 so that the surgical robotic system 600 can assist a user (e.g., a surgeon) in operating on a patient 210. The surgical robotic system 600 may be consistent with the surgical robotic systems 100 and 300 described previously.

[0073] Tracking array 612 can be mounted on instrument 608 to monitor the position and orientation of instrument tool 608. Tracking array 612 can be attached to instrument 608 and can include tracking markers 804. Figure 8 As best seen in FIG. 1 , the tracking marker 804 may be, for example, a light emitting diode and / or other type of reflective marker (e.g., marker 118 as described elsewhere herein). The tracking device may be one or more line of sight devices associated with the surgical robotic system. As an example, the tracking device may be one or more cameras 200, 326 associated with the surgical robotic system 100, 300, and may also track the tracking array 612 to obtain a defined domain or relative orientation of the instrument 608 relative to the robotic arm 604, the robotic base 610, the end effector 602, and / or the patient 210. The tracking device may be consistent with those structures described in conjunction with the camera support 302 and the tracking subsystem 532.

[0074] Fig. 7A , 7B7C show top, front, and side views, respectively, of an end effector 602 consistent with an exemplary embodiment. The end effector 602 may include one or more tracking markers 702. The tracking markers 702 may be light emitting diodes or other types of active and passive markers, such as the tracking markers 118 described previously. In an exemplary embodiment, the tracking markers 702 are active infrared emitting markers that are activated by an electrical signal, such as an infrared light emitting diode (LED). Thus, the tracking markers 702 may be activated such that the infrared markers 702 are visible to the camera 200, 326, or may be deactivated such that the infrared markers 702 are not visible to the camera 200, 326. Thus, when the markers 702 are active, the end effector 602 may be controlled by the system 100, 300, 600, and when the markers 702 are deactivated, the end effector 602 may be locked in place and cannot be moved by the system 100, 300, 600.

[0075] The marker 702 may be disposed on or within the end effector 602 in a manner such that the marker 702 may be visible to one or more cameras 200, 326 or other tracking devices associated with the surgical robotic system 100, 300, 600. The camera 200, 326 or other tracking device may track the end effector 602 as it moves to different positions and viewing angles by following the movement of the tracking marker 702. The position of the marker 702 and / or the end effector 602 may be displayed on a display 110, 304 associated with the surgical robotic system 100, 300, 600, for example. Figure 2 The display 110 and / or Figure 3 The display 304 is shown. This display 110, 304 may allow the user to ensure that the end effector 602 is in a desired position with respect to the robotic arm 604, the robotic base 610, the patient 210, and / or the user.

[0076] For example, if Fig. 7A As shown, the markers 702 can be placed around the surface of the end effector 602 so that a tracking device placed away from the surgical field of view 208 and facing the robot 102, 301 and the camera 200, 326 can view at least three of the markers 702 through a series of common orientations of the end effector 602 relative to the tracking device 100, 300, 600. For example, distributing the markers 702 in this manner allows the end effector 602 to be monitored by the tracking device as it translates and rotates in the surgical field of view 208.

[0077] Additionally, in an exemplary embodiment, the end effector 602 may be equipped with an infared (IR) receiver that may detect when the external camera 200, 326 is ready to read the marker 702. Upon this detection, the end effector 602 may then illuminate the marker 702. The detection by the IR receiver that the external camera 200, 326 is ready to read the marker 702 may indicate a need to synchronize the duty cycle of the marker 702 (which may be a light emitting diode) to the external camera 200, 326. This may also allow the robotic system as a whole to achieve lower power consumption, whereby the marker 702 will only be illuminated at appropriate times rather than being continuously illuminated. Additionally, in an exemplary embodiment, the marker 702 may be turned off to prevent interference with other navigation tools (e.g., different types of surgical instruments 608).

[0078] Figure 8 A type of surgical instrument 608 is depicted that includes a tracking array 612 and a tracking marker 804. The tracking marker 804 can be of any type described herein, including but not limited to a light emitting diode or a reflective ball. The marker 804 is monitored by a tracking device associated with the surgical robotic system 100, 300, 600, and the marker can be one or more of the line-of-sight cameras 200, 326. The cameras 200, 326 can track the positioning of the instrument 608 based on the position and orientation of the tracking array 612 and the marker 804. A user, such as a surgeon 120, can orient the instrument 608 in a manner such that the tracking array 612 and the marker 804 are sufficiently discernible by the tracking device or camera 200, 326 to display the instrument 608 and the marker 804, for example, on the display 110 of the exemplary surgical robotic system.

[0079] Surgeon 120 can place instrument 608 into guide tube 606 of end effector 602 and adjust instrument 608 in this way. Figure 8602 is apparent. The size and configuration of the hollow tube or conduit 114, 606 of the end effector 112, 310, 602 is set to receive at least a portion of the surgical instrument 608. The conduit 114, 606 is configured to be oriented by the robotic arm 104 so that the insertion and trajectory of the surgical instrument 608 can reach the desired anatomical target in or on the patient 210. The surgical instrument 608 may include at least a portion of a generally cylindrical instrument. Although a screwdriver is illustrated as the surgical tool 608, it should be understood that any suitable surgical tool 608 can be positioned by the end effector 602. As an example, the surgical instrument 608 may include one or more guide wires, cannulas, retractors, drills, reamers, screwdrivers, insertion tools, removal tools, etc. Although the hollow tube 114, 606 is generally shown as having a cylindrical configuration, it will be understood by those skilled in the art that the conduit 114, 606 can have any suitable shape, size, and configuration desired for accommodating the surgical instrument 608 and accessing the surgical site.

[0080] 9A to 9C A portion of an end effector 602 and a robotic arm 604 are shown consistent with an exemplary embodiment. The end effector 602 may further include a body 1202 and a clamp 1204. The clamp 1204 may include a handle 1206, a ball 1208, a spring 1210, and a lip 1212. The robotic arm 604 may further include a recess 1214, a mounting plate 1216, a lip 1218, and a magnet 1220.

[0081] The end effector 602 can mechanically interface and / or engage the surgical robot system and the robotic arm 604 through one or more couplings. For example, the end effector 602 can be engaged with the robotic arm 604 through a positioning coupling and / or a reinforcement coupling. Through these couplings, the end effector 602 can be fastened to the robotic arm 604 outside the flexible sterile barrier. In an exemplary embodiment, the positioning coupling can be a magnetic kinematic bracket, and the reinforcement coupling can be a five-bar cross-center clamp linkage.

[0082] With respect to the positioning coupling, the robotic arm 604 may include a mounting plate 1216 (which may be a non-magnetic material), one or more recesses 1214, a lip 1218, and magnets 1220. The magnets 1220 are mounted below each recess 1214. Portions of the fixture 1204 may include a magnetic material and be attracted by the one or more magnets 1220. Through the magnetic attraction of the fixture 1204 and the robotic arm 604, the ball 1208 becomes seated in the corresponding recess 1214. For example, as Fig. 9B The ball 1208 shown will be placed in the recess 1214, as shown in FIG. Fig.9AAs shown. This arrangement can be considered a magnetically assisted kinematic coupling. The magnets 1220 can be configured to be strong enough to support the entire weight of the end effector 602 regardless of the orientation of the end effector 602. The positioning coupling can be any type of kinematic mounting that uniquely constrains six degrees of freedom.

[0083] With respect to the enhanced coupling, portions of the clamp 1204 can be configured as fixed ground linkages, and such a clamp 1204 can be used as a five-bar linkage. When the lip 1212 and the lip 1218 engage the clamp 1204 in a manner that secures the end effector 602 and the robotic arm 604, closing the clamp handle 1206 can secure the end effector 602 to the robotic arm 604. When the clamp handle 1206 is closed, the spring 1210 can be stretched or stressed when the clamp 1204 is in the locked position. The locked position can be a position that provides a linkage that passes through the center. Because the closed position passes through the center, the linkage will not open without a force applied to the clamp handle 1206 to release the clamp 1204. Therefore, in the locked position, the end effector 602 can be securely secured to the robotic arm 604.

[0084] The spring 1210 may be a tensioned bending beam. The spring 1210 may be composed of a material exhibiting high stiffness and high yield strain, such as virgin PEEK (polyetheretherketone). The connection between the end effector 602 and the robotic arm 604 may provide a sterile barrier between the end effector 602 and the robotic arm 604 without interfering with the fastening of the two couplings.

[0085] The enhanced coupling may be a linkage with multiple spring members. The enhanced coupling may lock with a cam or friction based mechanism. The enhanced coupling may also be a sufficiently powerful electromagnet that will support the fastening of the end effector 102 to the robotic arm 604. The enhanced coupling may be a multi-piece collar that is completely separate from the end effector 602 and / or robotic arm 604, slides over the joint between the end effector 602 and the robotic arm 604, and is fastened with a screw mechanism, a cross-center linkage, or a cam mechanism.

[0086] refer to Fig.10 and 11 Before or during a surgical procedure, certain registration procedures may be performed to track the target anatomy of the patient 210 in navigation space and imaging space. To perform such registration, a registration system 1400 may be used, such as Fig.10 shown.

[0087] To track the position of the patient 210, the patient tracking device 116 may include a patient fixation device 1402 to be fixed to a rigid anatomical structure of the patient 210, and a dynamic reference base (DRB) 1404 may be securely attached to the patient fixation device 1402. For example, the patient fixation device 1402 may be inserted into an opening 1406 of the dynamic reference base 1404. The dynamic reference base 1404 may include markers 1408 visible to the tracking device (e.g., the tracking subsystem 532). These markers 1408 may be optical markers or reflective balls, such as the tracking markers 118, as previously described.

[0088] Patient fixation apparatus 1402 is attached to a rigid anatomical structure of patient 210 and may remain attached throughout the surgical procedure. In an exemplary embodiment, patient fixation apparatus 1402 is attached to a rigid area of ​​patient 210, such as a bone located away from a target anatomical structure undergoing the surgical procedure. To track the target anatomical structure, dynamic reference base 1404 is associated with the target anatomical structure by using a registration fixture temporarily placed on or near the target anatomical structure to register dynamic reference base 1404 with the location of the target anatomical structure.

[0089] The registration fixture 1410 is attached to the patient fixation apparatus 1402 by using the pivot arm 1412. The pivot arm 1412 is attached to the patient fixation apparatus 1402 by inserting the patient fixation apparatus 1402 through an opening 1414 of the registration fixture 1410. The pivot arm 1412 is attached to the registration fixture 1410 by, for example, inserting a knob 1416 through an opening 1418 of the pivot arm 1412.

[0090] Using the pivot arm 1412, the registration fixture 1410 can be placed over the target anatomy and its position can be determined in imaging space and navigation space using tracking markers 1420 and / or fiducials 1422 on the registration fixture 1410. The registration fixture 1410 can include a collection of markers 1420 that are visible in the navigation space (e.g., the markers 1420 can be detected by the tracking subsystem 532). As previously described herein, the tracking markers 1420 can be optical markers that are visible under infrared light. The registration fixture 1410 can also include a collection of fiducials 1422 that are visible in the imaging space (e.g., a three-dimensional CT image), such as bearing balls. As described with respect to Fig.11In more detail, using the registration fixture 1410, the target anatomy can be associated with the dynamic reference base 1404, allowing the depiction of the object in the navigation space to be superimposed on the image of the anatomy. The dynamic reference base 1404 located at a location away from the target anatomy can become a reference point, allowing the registration fixture 1410 and / or the pivot arm 1412 to be removed from the surgical field.

[0091] Fig.11 An exemplary method 1500 for registration consistent with the present disclosure is provided. The method 1500 begins at step 1502, where a graphical representation (or image) of a target anatomical structure can be imported into the system 100, 300, 600, such as the computer 408. The graphical representation can be a three-dimensional CT or fluoroscopic scan of the target anatomical structure of the patient 210, which contains a detectable imaging pattern of the registration fixture 1410 and the fiducials 1420.

[0092] At step 1504, the imaged pattern of fiducials 1420 is detected and registered in imaging space and stored in computer 408. Optionally, at this point at step 1506, a graphical representation of registration fixture 1410 may be superimposed on the image of the target anatomy.

[0093] At step 1508, the navigation pattern of the registration fixture 1410 is detected and registered by identifying the marker 1420. The marker 1420 can be an optical marker that is recognized in the navigation space by the tracking subsystem 532 via the position sensor 540 through infrared light. Therefore, the location, orientation, and other information of the target anatomical structure are registered in the navigation space. Therefore, the registration fixture 1410 can be recognized in the imaging space by using the reference point 1422, and the registration fixture can be recognized in the navigation space by using the marker 1420. At step 1510, the registration of the registration fixture 1410 in the imaging space is transferred to the navigation space. For example, this transfer is completed by using the relative position of the imaging pattern of the reference point 1422 compared to the position of the navigation pattern of the marker 1420.

[0094] At step 1512, the registration of the navigation space of the registration fixture 1410 (already registered with the imaging space) is further transferred to the navigation space of the dynamic registration array 1404 attached to the patient fixation apparatus 1402. Thus, the registration fixture 1410 can be removed, and because the navigation space is associated with the imaging space, the dynamic reference base 1404 can be used to track the target anatomy in both the navigation space and the imaging space.

[0095] At steps 1514 and 1516, the navigation space may be superimposed on the imaging space, and the object may have a marker visible in the navigation space (e.g., surgical instrument 608 with optical marker 804). The object may be tracked by the graphical representation of surgical instrument 608 on the image of the target anatomy.

[0096] Figures 12A-12B An imaging device 1304 is shown that can be used in conjunction with the robotic system 100, 300, 600 to obtain pre-operative, intra-operative, post-operative, and / or real-time image data of the patient 210. Using the imaging system 1304, any suitable subject can be imaged for any suitable procedure. The imaging system 1304 can be any imaging device, such as an imaging device 1306 and / or a C-arm 1308 device. It may be desirable to take x-rays of the patient 210 from a plurality of different positions without requiring frequent manual repositioning of the patient 210 that may be required in an x-ray system. Fig. 12A As shown, the imaging system 1304 can be in the form of a C-shaped arm 1308, which includes an elongated C-shaped member terminating at a relatively distal end 1312 of the "C" shape. The C-shaped member 1300 can further include an x-ray source 1314 and an image receptor 1316. The space within the C-shaped arm 1308 of the arm can provide a physician with space to care for the patient without being substantially disturbed by the x-ray support structure 1318. Fig. 12B As shown, the imaging system may include an imaging device 1306 having a gantry housing 1324 attached to a support structure imaging device support structure 1328, such as a wheeled mobile cart 1330 with wheels 1332, which may surround an image capture portion (not shown). The image capture portion may include an x-ray source and / or emitting portion and an x-ray receiving and / or image receiving portion, which may be positioned approximately one hundred eighty degrees apart from each other and mounted on a rotor (not shown) relative to a track of the image capture portion. The image capture portion may be operable to rotate three hundred sixty degrees during image acquisition. The image capture portion may rotate about a center point and / or axis, thereby allowing image data of the patient 210 to be acquired from multiple directions or multiple planes. Although certain imaging systems 1304 are exemplified herein, it should be understood that a person of ordinary skill in the art may select any suitable imaging system.

[0097] Now turn to see Figures 13A-13C The surgical robotic system 100, 300, 600 relies on accurate positioning of the end effector 112, 602, surgical instrument 608, and / or patient 210 (e.g., patient tracking device 116) relative to a desired surgical area. Figures 13A-13C In the illustrated embodiment, the tracking markers 118 , 804 are rigidly attached to the instrument 608 and / or a portion of the end effector 112 .

[0098] Fig.13A A portion of a surgical robotic system 100 is depicted having a robot 102 including a base 106, a robotic arm 104, and an end effector 112. Other elements not shown, such as displays, cameras, etc., may also be present as described herein. Fig. 13B A close-up view of the end effector 112 is depicted with the catheter 114 and a plurality of tracking markers 118 rigidly secured to the end effector 112. In this embodiment, the plurality of tracking markers 118 are attached to the catheter 112. Fig. 13C An instrument 608 (in this case, a stylet 608A) is depicted having a plurality of tracking markers 804 rigidly attached to the instrument 608. As described elsewhere herein, the instrument 608 may include any suitable surgical instrument, such as, but not limited to, a guidewire, a cannula, a retractor, a drill, an reamer, a screwdriver, an insertion tool, a removal tool, and the like.

[0099] When an instrument 608, end effector 112, or other object is to be tracked in 3D, an array of tracking markers 118, 804 can be rigidly attached to a portion of the tool 608 or end effector 112. Preferably, the tracking markers 118, 804 are attached so that the markers 118, 804 do not interfere (e.g., do not interfere with surgical manipulation, visibility, etc.). The markers 118, 804 can be attached to the instrument 608, end effector 112, or other object to be tracked with the array 612, for example. Typically, three or four markers 118, 804 are used with the array 612. The array 612 may include linear segments, cross-pieces, and may be asymmetric so that the markers 118, 804 are in different relative positions and locations with respect to each other. For example, as shown in FIG. Fig. 13C , a probe 608A having a 4-marker tracking array 612 is shown, and Fig. 13B An end effector 112 with a different 4-marker tracking array 612 is depicted.

[0100] exist Fig. 13C , the tracking array 612 serves as the handle 620 of the probe 608A. Thus, the four markers 804 are attached to the handle 620 of the probe 608A, out of the way of the shaft 622 and the tip 624. Stereophotogrammetric tracking of these four markers 804 allows the instrument 608 to be tracked as a rigid body and allows the tracking system 100, 300, 600 to accurately determine the position of the tip 624 and the orientation of the shaft 622 as the probe 608A moves around in front of the tracking camera 200, 326.

[0101] In order to be able to automatically track one or more tools 608, end effectors 112, or other objects to be tracked in 3D (e.g., multiple rigid bodies), the markers 118, 804 on each tool 608, end effector 112, or the like are arranged asymmetrically at known marker spacings. The reason for the asymmetrical alignment is to make it clear which marker 118, 804 corresponds to a specific location on the rigid body and whether the marker 118, 804 is viewed from the front or back (i.e., mirrored). For example, if the markers 118, 804 are arranged in a square on the tool 608 or end effector 112, it will be unclear to the system 100, 300, 600 which marker 118, 804 corresponds to which corner of the square. For example, for the probe 608A, it is unclear which marker 804 is closest to the shaft 622. Therefore, the direction in which the shaft 622 extends from the array 612 is unknown. Therefore, each array 612, and therefore each tool 608, end effector 112, or other object to be tracked, should have a unique marker pattern to enable it to be distinguished from other tools 608 or other objects being tracked. The asymmetric and unique marker pattern allows the system 100, 300, 600 to detect individual markers 118, 804 and then check the marker intervals against a stored template to determine which tool 608, end effector 112, or other object they represent. The detected markers 118, 804 can then be automatically classified and assigned to each tracked object in the correct order. Without this information, rigid body calculations cannot be performed to extract key geometric information, such as the alignment of the tool tip 624 and the shaft 622, unless the user manually specifies which detected marker 118, 804 corresponds to which location on each rigid body. These concepts are generally known to those skilled in 3D optical tracking methods.

[0102] Now turn to see Figures 14A-14D , shows an alternative version of the end effector 912 with movable tracking markers 918A-918D. Fig.14A In FIG. 1 , an array with removable tracking marks 918A-918D is shown in a first configuration and in Fig. 14B , the removable tracking marks 918A-918D are shown in a second configuration that is angled relative to the first configuration. Fig. 14C As shown, for example, by Fig.14A a template of tracking markers 918A-918D as seen by the camera 200, 326 in the first configuration; and Fig.14D As shown, for example, by Fig. 14B A template of tracking markers 918A-918D as seen by the camera 200, 326 in the second configuration.

[0103] In this embodiment, 4-marker array tracking is contemplated where the markers 918A-918D are not all located in fixed positions relative to a rigid body, and instead one or more of the array markers 918A-918D may be adjusted, for example during testing, to give updated information about the rigid body being tracked without hampering the process of automatic detection and classification of the tracked markers 918A-918D.

[0104] When tracking any tool, such as a guide tube 914 connected to an end effector 912 of a robotic system 100, 300, 600, the main purpose of the tracking array is to update the position of the end effector 912 in the camera coordinate system. Fig. 13B , an array 612 of reflective markers 118 rigidly extends from the catheter 114. Because the tracking markers 118 are rigidly attached, knowledge of the marker positions in the camera coordinate system also provides the accurate positions of the centerline, tip, and tail of the catheter 114 in the camera coordinate system. Typically, information about the position of the end effector 112 from this array 612 and information about the position of the target track from another tracked source are used to calculate the required movement that must be input for each axis of the robot 102 to move the catheter 114 into alignment with the track and move the tip to a specific position along the track vector.

[0105] Sometimes, a desired trajectory is in an inconvenient or inaccessible location, but if the guide tube 114 can be rotated, then the desired trajectory can be reached. For example, if the guide tube 114 can be rotated upward beyond the limits of the pitch (wrist up-down angle) axis, then a very steep trajectory pointing away from the base 106 of the robot 102 may be reachable, but if the guide tube 114 is attached parallel to the plate connecting it to the end of the wrist, then the very steep trajectory may not be reachable. In order to reach this trajectory, the base 106 of the robot 102 can be moved, or a different end effector 112 with a different guide tube attached can be swapped with the working end effector. Both solutions can be time consuming and cumbersome.

[0106] like Fig.14A and 14BAs best seen in FIG. 1 , if the array 908 is configured so that one or more of the markers 918A-918D are not in a fixed position, and instead, one or more of the markers 918A-918D can be adjusted, rotated, pivoted, or moved, the robot 102 can provide updated information about the object being tracked without hindering the detection and tracking process. For example, one of the markers 918A-918D can be fixed in place and the other markers 918A-918D can be movable; two of the markers 918A-918D can be fixed in place and the other markers 918A-918D can be movable; three of the markers 918A-918D can be fixed in place and the other markers 918A-918D can be movable; or all of the markers 918A-918D can be movable.

[0107] exist Fig.14A and 14B , markers 918A, 918B are rigidly connected directly to the base 906 of the end effector 912, and markers 918C, 918D are rigidly connected to the tube 914. Similar to the array 612, an array 908 can be provided to attach the markers 918A-918D to the end effector 912, the instrument 608, or other objects to be tracked. However, in this case, the array 908 is composed of multiple separate components. For example, the markers 918A, 918B can be connected to the base 906 by a first array 908A, and the markers 918C, 918D can be connected to the tube 914 by a second array 908B. The marker 918A can be attached to the first end of the first array 908A, and the marker 918B can be separated by a linear distance and attached to the second end of the first array 908A. While the first array 908 is generally linear, the second array 908B has a curved or V-shaped configuration with the respective root ends connected to the catheter 914 and radiating therefrom to the distal ends in a V-shape with the marker 918C at one distal end and the marker 918D at the other distal end. While specific configurations are exemplified herein, it should be understood that other asymmetric designs including different numbers and types of arrays 908A, 908B and different arrangements, numbers and types of markers 918A-918D are contemplated.

[0108] The catheter 914 may be movable, rotatable, or pivotable relative to the base 906, for example, across a hinge 920 or other connector to the base 906. Thus, the markers 918C, 918D are movable so that when the catheter 914 pivots, rotates, or moves, the markers 918C, 918D also pivot, rotate, or move. Fig.14A As best seen in FIG. 1 , the catheter 914 has a longitudinal axis 916 that is aligned in a generally orthogonal or vertical orientation such that the markings 918A-918D have a first configuration. Fig. 14B , the catheter 914 is pivoted, rotated or moved such that the longitudinal axis 916 is now angled relative to the vertical orientation such that the markings 918A-918D have a second configuration that is different from the first configuration.

[0109] Compared to Figures 14A-14D In the described embodiment, if there is a rotation between the guide tube 914 and the arm 104 (e.g., wrist attachment), where all four markers 918A-918D remain rigidly attached to the guide tube 914, and this rotation is adjusted by the user, then the robotic system 100, 300, 600 will not be able to automatically detect that the guide tube 914 orientation has changed. The robotic system 100, 300, 600 will track the position of the marker array 908 and will calculate the wrong robot axis movement assuming that the guide tube 914 is attached to the wrist (robotic arm 104) in the previous orientation. By keeping one or more markers 918A-918D (e.g., two markers 918C, 918D) rigidly on the tube 914 and keeping one or more markers 918A-918D (e.g., two markers 918A, 918B) across the rotation, automatic detection of the new position becomes possible and the correct robot movement is calculated based on the detection of the new tool or end effector 112, 912 on the end of the robotic arm 104.

[0110] One or more of the markers 918A-918D are configured to move, pivot, rotate, etc. according to any suitable manner. For example, the markers 918A-918D may be moved by a hinge 920 such as a clamp, spring, lever, slide, toggle, etc., or any other suitable mechanism for moving the markers 918A-918D individually or in combination, moving the arrays 908A, 908B individually or in combination, moving any portion of the end effector 912 relative to another portion, or moving any portion of the tool 608 relative to another portion.

[0111] like Fig.14A and 14B 908 and the conduit 914 can become reconfigurable by simply loosening a clamp or hinge 920, moving portions of the array 908A, 908B relative to other portions 908A, 908B, and re-tightening the hinge 920 so that the conduit 914 is oriented in a different position. For example, two markers 918C, 918D can be rigidly interconnected with the tube 914, and two markers 918A, 918B can be rigidly interconnected across a hinge 920 to a base 906 of an end effector 912 attached to the robotic arm 104. The hinge 920 can be in the form of a clamp, such as a wing nut, that can be loosened and re-tightened to allow the user to adjust the configuration in a first configuration ( Fig.14A ) and the second configuration ( Fig. 14B ) to quickly switch between them.

[0112] Cameras 200, 326 detect e.g. Fig. 14C and 14D If array 908 is in a first configuration ( Fig.14A ) and the tracking camera 200, 326 detects the markers 918A-918D, then the tracked markers are Fig. 14C 1 matches the array template 1 shown in FIG. If array 908 is the second configuration ( Fig. 14B ) and the tracking cameras 200, 326 detect the same markers 918A-918D, then the tracked markers are the same as Fig.14D Array Template 1 and Array Template 2 are recognized by the system 100, 300, 600 as two distinct tools, each with its own uniquely defined spatial relationship between the guide tube 914, markers 918A-918D, and robot attachment. The user can therefore adjust the position of the end effector 912 between the first configuration and the second configuration without notifying the system 100, 300, 600 of the change, and the system 100, 300, 600 will appropriately adjust the movement of the robot 102 to stay on track.

[0113] In this embodiment, there are two assembly locations where the marker array matches a unique template that allows the system 100, 300, 600 to recognize the assembly as two different tools or two different end effectors. Fig. 14C and 14D 1 and array template 2) shown in the figure, or in any position of external rotation, the markers 918A-918D will not match any template, and although the camera 200, 326 detects the individual markers 918A-918D, the system 100, 300, 600 will not detect that any array exists, which has the same result as if the markers 918A-918D were temporarily blocked from the field of view of the camera 200, 326. It should be understood that other array templates may exist for other configurations, such as to identify different instruments 608 or other end effectors 112, 912, etc.

[0114] In the described embodiment, Fig.14A and 14BTwo discrete assembly positions are shown. However, it should be appreciated that there may be multiple discrete positions on a rotational joint, linear joint, combination of rotational and linear joints, pegboard, or other assembly where a unique marking template may be generated by adjusting the position of one or more markings 918A-918D of the array relative to other markings, where each discrete position matches a specific template and defines a unique tool 608 or end effector 112, 912 by a different known attribute. Additionally, while illustrated with respect to an end effector 912, it should be appreciated that movable and fixed markings 918A-918D may be used with any suitable instrument 608 or other object to be tracked.

[0115] When using an external 3D tracking system 100, 300, 600 to track a fully rigid body array of three or more markers attached to the end effector 112 of the robot (e.g., Fig.13A and 13B 106 ), it is possible to directly track or calculate the 3D position of each segment of the robot 102 in the coordinate system of the camera 200, 326. The geometric orientation of the joints relative to the tracker is known by design, and the linear or angular positions of the joints are known from the encoders of each motor of the robot 102, thereby completely defining the 3D position of all moving parts from the end effector 112 to the base 116. Similarly, if the tracker is mounted on the base 106 of the robot 102 (not shown), then it is likewise possible to track or calculate the 3D position of each segment of the robot 102 from the base 106 to the end effector 112 based on the joint geometry and joint positions known from the encoders of each motor.

[0116] In some cases, it may be desirable to track the positions of all segments of the robot 102 from fewer than three markers 118 rigidly attached to the end effector 112. Specifically, if the tool 608 is introduced into the catheter 114, then the fully rigid body motion of the robot 902 may need to be tracked with only one additional marker 118 being tracked.

[0117] Now turn to see Figures 15A-15E , shows an alternative version of an end effector 1012 having only a single tracking marker 1018. The end effector 1012 can be similar to another end effector described herein, and can include a guide tube 1014 extending along a longitudinal axis 1016. Similar to the other tracking markers described herein, the single tracking marker 1018 can be rigidly attached to the guide tube 1014. This single marker 1018 can serve to add a missing degree of freedom to allow for fully rigid body tracking, and / or can serve to act as a surveillance marker to ensure that assumptions about the robot and camera positioning are valid.

[0118] A single tracking marker 1018 may be attached to the robotic end effector 1012 as a rigid extension to the end effector 1012 that protrudes in any convenient direction and does not obstruct the surgeon's field of view. The tracking marker 1018 may be attached to the catheter 1014 or any other suitable location on the end effector 1012. When attached to the catheter 1014, the tracking marker 1018 may be positioned at a location between the first and second ends of the catheter 1014. For example, at Fig.15A , a single tracking marker 1018 is shown as a reflective sphere mounted on the end of a narrow shaft 1017 extending forward from the catheter 1014 and positioned longitudinally above the midpoint of the catheter 1014 and below the entrance of the catheter 1014. This position allows the marker 1018 to be generally visible by the camera 200, 326 and will not block the vision of the surgeon 120 or collide with other tools or objects in the surgical vicinity. In addition, the catheter 1014 with the marker 1018 in this position is designed so that the array of markers on any tool 608 introduced into the catheter 1014 is visible at the same time as the single marker 1018 on the catheter 1014 is visible.

[0119] like Fig. 15B 1014, the instrument 608 becomes mechanically constrained in four of the six degrees of freedom. That is, the instrument 608 cannot rotate in any direction except about the longitudinal axis 1016 of the catheter 1014, and the instrument 608 cannot translate in any direction except along the longitudinal axis 1016 of the catheter 1014. In other words, the instrument 608 can only translate along and rotate about the centerline of the catheter 1014. If two other parameters, such as (1) the rotation angle about the longitudinal axis 1016 of the catheter 1014; and (2) the position along the catheter 1014, are known, then the position of the end effector 1012 in the camera coordinate system is fully defined.

[0120] Reference Fig. 15C , the system 100, 300, 600 should be able to know when the tool 608 is actually positioned inside the catheter 1014, rather than being instead positioned outside the catheter 1014 and simply somewhere within the field of view of the camera 200, 326. The tool 608 has a longitudinal axis or centerline 616 and an array 612 having a plurality of tracked markers 804. Rigid body calculations can be used to determine where the centerline 616 of the tool 608 is located in the camera coordinate system based on the tracked position of the array 612 on the tool 608.

[0121] The fixed normal (vertical) distance DF from the single marker 1018 to the centerline or longitudinal axis 1016 of the catheter 1014 is fixed and geometrically known, and the position of the single marker 1018 can be tracked. Therefore, when the detected distance DD from the tool centerline 616 to the single marker 1018 matches the known fixed distance DF from the catheter centerline 1016 to the single marker 1018, it can be determined that the tool 608 is within the catheter 1014 (the centerlines 616, 1016 of the tool 608 coincide with the catheter 1014) or at a point in the possible location where this distance DD matches the fixed distance DF. For example, at Fig. 15C , the detected normal distance DD from the tool centerline 616 to the single marker 1018 matches the fixed distance DF from the catheter centerline 1016 to the single marker 1018 in the two data frames (tracked marker coordinates) represented by the transparent tool 608 in the two positions, and therefore additional consideration may be required to determine when the tool 608 is positioned in the catheter 1014.

[0122] Now turn to see Fig.15D , programmed logic may be used to find a frame of tracking data in which the detected distance DD from the tool centerline 616 to the single marker 1018 remains fixed at the correct length regardless of the tool 608 moving in space relative to the single spherical surface 1018 by more than a certain minimum distance to satisfy the condition that the tool 608 moves within the catheter 1014. For example, a first frame F1 may be detected by the tool 608 in a first position, and a second frame F2 may be detected by the tool 608 in a second position (i.e., linearly moved relative to the first position). The markers 804 on the tool array 612 may move from the first frame F1 to the second frame F2 by more than a given amount (e.g., more than 5 mm total). Even with this movement, the detected distance DD from the tool centerline vector C' to the single marker 1018 is substantially the same in both the first frame F1 and the second frame F2.

[0123] Logically, the surgeon 120 or user can place the tool 608 within the catheter 1014 and rotate or slide the tool 608 slightly down into the catheter 1014, and the system 100, 300, 600 will be able to detect that the tool is within the catheter 1014 from tracking five markers (the four markers 804 on the tool 608 plus the single marker 1018 on the catheter 1014). Knowing that the tool 608 is within the catheter 1014, all six degrees of freedom that spatially define the position and orientation of the robotic end effector 1012 can be calculated. Without the single marker 1018, even if it is known with certainty that the tool 608 is within the catheter 1014, it is not known where the catheter 1014 is located along the centerline vector C' of the tool and how the catheter 1014 is rotated relative to the centerline vector C'.

[0124] Focus on Fig.15E , in the case where the presence of a single marker 1018 is tracked and there are four markers 804 on the tool 608, it is possible to construct the centerline vector C' and the normal vector of the catheter 1014 and the tool 608 through the single marker 1018 and through the centerline vector C'. This normal vector has an orientation that intersects the centerline vector C' at a known orientation and at a specific fixed position relative to the forearm of the robot distal to the wrist (in this example, parallel to the segment orientation). For convenience, three mutually orthogonal vectors k', j', i' can be constructed, such as Fig.15E , thereby defining the rigid body position and orientation of the catheter 1014. One of the three mutually orthogonal vectors k' is composed of the centerline vector C', the second vector j' is composed of the normal vector passing through the single marker 1018, and the third vector i' is the vector cross product of the first vector k' and the second vector j'. When all joints are at zero, the robot joint positions relative to these vectors k', j', i' are known and fixed, and therefore the rigid body calculation can be used to determine the position of any section of the robot relative to these vectors k', j', i' when the robot is in the starting position. During robot movement, if the position of the tool marker 804 (when the tool 608 is in the catheter 1014) and the position of the single marker 1018 are detected from the tracking system, and the angular / linear position of each joint is known from the encoder, then the position and orientation of any section of the robot can be determined.

[0125] In some embodiments, the orientation of the fixed tool 608 relative to the catheter 1014 may be useful. For example, the end effector catheter 1014 may be oriented in a specific position around its axis 1016 to allow machining or implant positioning. Although the orientation of any object attached to the tool 608 inserted into the catheter 1014 is known from the tracked marker 804 on the tool 608, the rotational orientation of the catheter 1014 itself in the camera coordinate system is unknown without an additional tracking marker 1018 (or multiple tracking markers in other embodiments) on the catheter 1014. This marker 1018 provides a substantially "clock position" from -180° to +180° based on the orientation of the marker 1018 relative to the centerline vector C'. Therefore, a single marker 1018 can provide additional degrees of freedom to allow fully rigid body tracking, and / or can serve as a monitoring marker to ensure that assumptions about robot and camera positioning are valid.

[0126] Fig.161 is a block diagram of a method 1100 for navigating and moving the end effector 1012 of the robot 102 (or any other end effector described herein) to a desired target trajectory. Another use of a single marker 1018 on the robot end effector 1012 or guide tube 1014 is to enable automated safe movement of the robot 102 as part of the method 1100 without a full tracking array attached to the robot 102. This method 1100 works when the tracking cameras 200, 326 do not move relative to the robot 102 (i.e., they are in a fixed position), the coordinate system of the tracking system is co-registered with the coordinate system of the robot, and the robot 102 is calibrated so that the position and orientation of the guide tube 1014 can be accurately determined in the robot Cartesian coordinate system based solely on the encoded position of each robot axis.

[0127] For this method 1100, the coordinate system of the tracker and the coordinate system of the robot must be co-registered, which means that a coordinate transformation from the Cartesian coordinate system of the tracking system to the Cartesian coordinate system of the robot is required. For convenience, this coordinate transformation can be a 4×4 matrix of translations and rotations, which is well known in the field of robotics. This transformation will be referred to as Tcr to refer to "Transformation-Camera to Robot". Once this transformation is known, any new frame of tracking data received as x, y, z coordinates in vector form for each tracked marker can be multiplied by the 4×4 matrix, and the resulting x, y, z coordinates will be in the coordinate system of the robot. To obtain Tcr, the full tracking array on the robot is tracked when it is rigidly attached to the robot at a known position in the robot's coordinate system, and then the known rigid body method is used to calculate the transformation of the coordinates. It should be obvious that when the additional markers 1018 are also read, any tool 608 inserted into the catheter 1014 of the robot 102 can provide the same rigid body information as the rigidly attached array. That is, rather than being inserted into a fixed position and orientation, the tool 608 only needs to be inserted into any position and at any rotation within the catheter 1014. Therefore, it is possible to determine the Tcr by inserting any tool 608 with a tracking array 612 into the catheter 1014 and reading the tool's array 612 plus a single marker 1018 of the catheter 1014 while determining the current position of the catheter 1014 in the robot's coordinate system from the encoders on each axis.

[0128] exist Fig.16Logic for navigating and moving the robot 102 to a target trajectory is provided in method 1100 of . Prior to entering loop 1102, it is assumed that a transformation Tcr has been previously stored. Therefore, prior to entering loop 1102, in step 1104, after securing the robot base 106, when the robot is static, greater than or equal to one frame of tracking data of the tool inserted in the catheter is stored; and in step 1106, a transformation Tcr of the robot catheter position from camera coordinates to robot coordinates is calculated from this static data and previous calibration data. Tcr should remain valid as long as the camera 200, 326 does not move relative to the robot 102. If the camera 200, 326 moves relative to the robot 102 and Tcr needs to be re-acquired, the system 100, 300, 600 can be caused to prompt the user to insert the tool 608 into the catheter 1014 and then automatically perform the necessary calculations.

[0129] In the flow chart of method 1100, each frame of collected data consists of a snapshot of the tracked position of the DRB 1404 on the patient 210, the tracked position of a single marker 1018 on the end effector 1014, and the position of each robot axis. From the positions of the robot's axes, the position of the single marker 1018 on the end effector 1012 is calculated. This calculated position is compared to the actual position of the marker 1018 as recorded from the tracking system. If the values ​​match, then it can be ensured that the robot 102 is in a known position. A transformation Tcr is applied to the tracked position of the DRB 1404 so that a target for the robot 102 can be provided according to the robot's coordinate system. The robot 102 can then be commanded to move to reach the target.

[0130] After steps 1104, 1106, loop 1102 includes step 1108 of receiving rigid body information of DRB 1404 from the tracking system; step 1110 of transforming the target tip and trajectory from image coordinates to tracking system coordinates; and step 1112 of transforming the target tip and trajectory from camera coordinates to robot coordinates (applying Tcr). Loop 1102 further includes step 1114 of receiving a single stray marker position of the robot from the tracking system; and step 1116 of transforming the single stray marker from tracking system coordinates to robot coordinates (applying stored Tcr). Loop 1102 also includes step 1118 of determining the current position of the single robot marker 1018 in the robot coordinate system according to forward kinematics. Information from steps 1116 and 1118 is used to determine step 1120 whether the stray marker coordinates from the transformed tracked position are consistent with the calculated coordinates within a given tolerance. If so, then proceed to step 1122 to calculate and apply robot movement to the target x, y, z and trajectory. If no, then proceed to step 1124: stop and require full array to be inserted into catheter 1014 before proceeding; step 1126: recalculate Tcr after array insertion; and proceed to repeat steps 1108, 1114 and 1118.

[0131] This method 1100 has advantages over methods that omit continuous monitoring of a single marker 1018 to verify position. Without a single marker 1018, it would still be possible to use the Tcr to determine the position of the end effector 1012 and send the end effector 1012 to the target position, but it would not be possible to verify that the robot 102 is actually in the expected position. For example, if the camera 200, 326 has been raised and the Tcr is no longer valid, the robot 102 will move to the wrong position. For this reason, the single marker 1018 provides safety value.

[0132] For a given fixed position of the robot 102, it is theoretically possible to move the tracking camera 200, 326 to a new position where the single tracked marker 1018 remains unmoved, since the single tracked marker is a single point and not an array. In this case, the system 100, 300, 600 will not detect any errors, since there will be agreement in the calculated and tracked positions of the single marker 1018. However, once the robot's axis causes the catheter 1012 to move to a new position, the calculated and tracked positions will not agree and the safety check will come into play.

[0133] For example, the term "monitoring marker" may be used in reference to a single marker in a fixed position relative to the DRB 1404. In this example, if the DRB 1404 is raised or otherwise moved, the relative position of the monitoring marker changes and the surgeon 120 may be alerted that there may be a problem with navigation. Similarly, in the embodiments described herein, the system 100, 300, 600 can continuously check whether the camera 200, 326 has moved relative to the robot 102 through a single marker 1018 on the catheter 1014 of the robot. If the registration of the coordinate system of the tracking system and the coordinate system of the robot is lost (for example, because the camera 200, 326 is raised or malfunctioning or because the robot malfunctions), the system 100, 300, 600 can alert the user and can make corrections. Therefore, this single marker 1018 can also be considered a monitoring marker for the robot 102.

[0134] It should be apparent that in the case where the full array is permanently mounted on the robot 102 (e.g., the plurality of tracking markers 702 are mounted on Figures 7A-7C 602 shown in FIG. 1 ), such functionality of a single marker 1018 as a robot monitoring marker is not needed because the camera 200, 326 is not required to be in a fixed position relative to the robot 102 and update the Tcr at each frame based on the tracked position of the robot 102. The reason for using a single marker 1018 instead of a full array is that the full array is bulkier and obtrusive, thereby blocking the surgeon's field of view and access to the surgical field of view 208 that is larger than the single marker 1018, and the line of sight to the full array is more easily blocked than the line of sight to a single marker 1018.

[0135] Now turn to see Figures 17A-17B 18A-18B, depicts an instrument 608 such as an implant holder 608B, 608C, which includes both a fixed tracking marker 804 and a removable tracking marker 806. The implant holder 608B, 608C may have a handle 620 and an outer shaft 622 extending from the handle 620. The shaft 622 may be positioned substantially perpendicular to the handle 620, as shown, or may be positioned in any other suitable orientation. An inner shaft 626 may extend through the outer shaft 622 at one end by a knob 628. Using a typical connection mechanism known to those skilled in the art, at the other end, the implant 10, 12 is connected to the shaft 622 at the tip 624 of the implant holder 608B, 608C. For example, the knob 628 may be rotated to expand or articulate the implant 10, 12. US Patent Nos. 8,709,086 and 8,491,659, which are incorporated herein by reference, describe expandable fusion devices and methods of installation.

[0136] When tracking a tool 608, such as an implant holder 608B, 608C, the tracking array 612 may include a combination of fixed markers 804 and one or more movable markers 806, which constitute the array 612 or are otherwise attached to the implant holder 608B, 608C. The navigation array 612 may include at least one or more (e.g., at least two) fixed position markers 804, which are positioned at known positions relative to the implant holder instruments 608B, 608C. These fixed markers 804 will not be able to move in any orientation relative to the instrument geometry and will be suitable for defining the position of the instrument 608 in space. In addition, there is at least one marker 806 that can be attached to the array 612 or the instrument itself, which can move (e.g., slide, rotate, etc.) within predetermined boundaries relative to the fixed marker 804. The system 100, 300, 600 (e.g., software) aligns the position of the movable marker 806 with a specific position, orientation, or other attribute (e.g., position) of the implant 10. Figures 17A-17B The height of the expandable intervertebral body spacer shown in, or Figures 18A-18B Thus, the system and / or user can determine the height or angle of the implant 10, 12 based on the position of the movable marker 806.

[0137] exist FIG. 17A to FIG. 17B In the embodiment shown in FIG. 6 , four fixed markers 804 are used to define the implant holder 608B, and a fifth movable marker 806 is capable of sliding within a predetermined path to provide feedback regarding the height of the implant (eg, a collapsed position or an expanded position). Fig.17A The expandable spacer 10 is shown at its initial height, and Fig. 17B The spacer 10 is shown in an expanded state, wherein the movable marker 806 is translated to different positions. In this case, the movable marker 806 moves closer to the fixed marker 804 when the implant 10 expands, but it is expected that this movement can be reversed or otherwise different. The amount of linear translation of the marker 806 will correspond to the height of the implant 10. Although only two positions are shown, it will be possible to use this as a continuous function, by which any given expansion height can be related to a specific position of the movable marker 806.

[0138] Now turn to see Figures 18A to 18B , four fixed markers 804 are used to define the implant holder 608C, and a fifth movable marker 806 is configured to slide within a predetermined path to provide feedback regarding the implant articulation angle. Fig.18A The articulated spacer 12 is shown in its initial linear state, and Fig.18BThe spacer 12 is shown in an articulated state at a certain offset angle, wherein the movable marker 806 is translated to different positions. The amount of linear translation of the marker 806 will correspond to the articulation angle of the implant 12. Although only two positions are shown, it is possible to use this as a continuous function, by which any given articulation height can be related to a specific position of the movable marker 806.

[0139] In these embodiments, removable marker 806 continues to slide to provide feedback about the attribute of implant 10,12 based on position.It is also expected that there may be a careful position that removable marker 806 must be in, and the careful position will also be able to provide other information about the implant attribute.In this case, each careful configuration of all marks 804,806 is relevant to the specific geometry of implant holder 608B, 608C and implant 10,12 on or under the specific height with specific orientation.In addition, any movement of removable marker 806 can be used for other variable attributes of the navigated implant of any other type.

[0140] Although depicted and described with respect to the linear movement of movable marker 806, movable marker 806 should not be limited to only sliding, because there may be rotation or other movement of marker 806 that may be applicable to the application of providing information about implant 10,12. Any relative position change between this set of fixed markers 804 and movable marker 806 may be relevant information of implant 10,12 or other devices. In addition, although expandable and articulated implant 10,12 are used as examples for explanation, instrument 608 may work with other medical devices and materials, such as spacers, cages, plates, fasteners, nails, screws, rods, pins, wire structures, sutures, anchoring clips, nails, stents, bone grafts, biological agents, etc.

[0141] One aspect of the present invention relating to determining the 3-dimensional position of an imaging arm of an imaging device for capturing an optimal image of a vertebral body will now be described with reference to FIGS. 19-27.

[0142] Most conventional systems do not have navigation capabilities and rely on the user to position the C-arm. A few systems may have some navigation functionality that allows the user to return to a previously stored position. In other words, existing systems may have the ability to let the user know where the imaging system may have been in the past. In contrast, the present invention as described in conjunction with Figures 19-27 proposes to let the user know where the imaging system needs to be in the future to capture the best image.

[0143] Fig.23320 is an example of an x-ray imaging device 2300 according to one aspect of the present invention that is capable of automatic positioning for the 3D position and orientation of its C-arm 2316. The imaging device 2300 includes a detector panel assembly 2314 that includes a sensor array (not shown) for receiving x-ray transmissions from an x-ray source 2312. The imaging device 2300 is more fully described in U.S. Patent No. 1,044,8910 assigned to the applicant of the present invention, which is incorporated herein by reference. The imaging device 2300 is capable of communicating with the surgical robot system 300 wirelessly via a physical I / O cable via a connector panel 320 or via well-known wireless transmission methods including WiFi, Bluetooth, etc.

[0144] Unlike imaging system 2300 which does not require a calibration ring, a manually operated C-arm such as 1308 would typically have a calibration ring such as Fig. 12A The calibration ring 2200 shown mounted to the detector panel assembly 1316. The calibration ring 2200 includes two spaced rings 2210, 2212, each having a planar surface. Each planar surface includes a plurality of radiopaque markers 2206, 2208 spaced apart from each other in a selected pattern. Two sets of multiple circumferentially spaced optical markers 2202, 2204 are also mounted to the rings 2210, 2212. The radiopaque markers 2206, 2208 are used to perform an initial registration of the imaging device 1308 (i.e., the mapping of the position and orientation of the C-arm relative to the patient from the imaging space to the camera coordinate system) so that the tracking subsystem 532 can track the position and orientation of the C-arm 1308 during the surgical procedure. For an automatically navigated imaging system 2300, the calibration ring is unnecessary, and the tracking and navigation of the system can be accomplished using optical markers 2310 or encoders positioned in each moving part of the system. The encoders can be used to mark the relative position and orientation of the C-arm 2316 at any time of use.

[0145] Once the initial registration has been performed, the camera 326 of the tracking subsystem 532 may continue to track the position and orientation of the C-arm 2316 during the surgical procedure via the optical markers 2202 , 2204 and, optionally, via the markers 2310 on the C-arm 2316 .

[0146] Fig.21 A flow chart illustrating a method of determining the 3-dimensional (3D) position and orientation of an imaging device for each spinal segment for taking optimal AP and transverse images such that only one set of images is required. Fig.21 The processing steps in the above can be performed by the image control module 409 in the computer 408, the processor of the imaging device 2300 itself, other remotely located processors, or a combination thereof. In one embodiment, the image control module 409 includes computer executable code stored in the memory 410.

[0147] In step 2100, a user (typically an X-ray technician in an operating room) positions the imaging device 2300 around a patient table (not shown) so that the patient lying on the table is within the C-arm 2316. Once the imaging device 2300 is positioned, the user can take a pair of x-ray images (one AP image and one lateral image) without regard to the accuracy or optimality of the positioning of the C-arm 2316, as long as the spinal segment of interest is included. Fig.26 A typical AP image 2602 and a lateral image 2604 are shown in FIG. Once these two images are captured, they are received by the computer 408 and stored.

[0148] In addition to the images, the computer 408 also receives and stores the 3D position and orientation of the C-arm (eg, the 3D position and orientation of the C-arm's imaging panel / intensifier or x-ray source or both) for each of the two images 2602 , 2604 .

[0149] In step 2102, the vertebral body of interest is segmented for later analysis. Segmentation is a process used to identify certain points or features on a body part, such as a vertebral body. The segmentation can be manual, semi-automatic, or fully automatic. Fig.26 An illustration of a segmented vertebra is shown in FIG. Semi-automatic or fully automatic segmentation methods for identifying relevant points of a vertebra are well known in the art. For example, an open source software program called "ITK-SNAP" (available at www.itksnap.net) allows a user to interactively segment each vertebra.

[0150] Step 2102 may also identify spinal segments as part of the segmentation process. This identification process may be completely manual, requiring the user to identify each segment. Alternatively, the identification process may be semi-automatic or fully automatic. In the semi-automatic case, the user may identify at least one segment, and the remaining segments may be automatically applied based on image processing. For example, once the user identifies a vertebra as L4 (e.g., Fig.26 ), the computer 408 automatically identifies all other segments, for example, based on the lordotic angle of the segmented vertebral body. As a double check, the computer 408 may require the user to confirm that the automatically identified segment is correct through a semi-automatic or fully automatic process.

[0151] In step 2104, the computer 408 asks the user to identify the spinal segments of interest. The user then identifies the segments displayed on the touch screen display device 304 (eg, the four segments from L1 to L4) using a graphical user interface, for example, by touching them.

[0152] In step 2106, the computer 408 retrieves from the database a 3D model 2702 of the spine containing the vertebral body of interest. The 3D model may be based on a statistical model that is not specific to any patient, as most spines generally follow a standard pattern, or it may be based on a relevant specific patient from a 3D scan. Alternatively, the standard 3D model may be enhanced by patient-specific data, such as the lordotic and kyphotic angles derived from the images 2602, 2604. The retrieved vertebral body 2702 is then scaled so that the size of the vertebral body is the same as those in the AP and transverse images. The scaling may be based on the segmentation information obtained from step 2102.

[0153] In step 2106, for each vertebra of interest, the computer 408 performs alignment of the retrieved 3D model of the selected vertebra with the corresponding segmented vertebra in the AP image 2602 and the transverse image 2604. For example, one method that may be used is "fluoro-CT merge". An algorithm for fluoro-CT merge can be found in the article entitled "Image-Assisted Navigation System for Spinal Surgery" published in Applied Bionics and Biomechanics, Vol. 2015, p. 9, article number 478062, May 28, 2015 (downloaded from http: / / dx.doi.org / 10.1155 / 2015 / 478062), which is incorporated herein by reference. In essence, the position and orientation (including X, Y, Z, yaw, roll, and pitch) of the 3D spinal model are adjusted by the computer 408 until optimal alignment is achieved.

[0154] Fig.27A and 27B The alignment method is illustrated graphically. Fig.27B A transverse test image 2710 from an x-ray source 2708 is shown. The transverse test image 2710 and the x-ray source 2706 correspond to the detector panel 2710 and the x-ray source 2312 of the detector panel assembly 2314 of the imaging device 2300, respectively, when the test image was taken. The AP test image 2710 and the x-ray source 2706 correspond to the detector panel 2710 and the x-ray source 2312 of the imaging device 2300, respectively, when the test image was taken. It can be seen that the model vertebral body 2702 is scaled and manipulated until the vertebral body most closely matches the corresponding vertebral body in the AP and transverse images.

[0155] Step 2106 is repeated for each vertebral body of interest identified in step 2104 .

[0156] Then, in step 2110, the computer 408 determines an optimal C-arm 2316 orientation and position (e.g., the 3D position and orientation of the detector panel 2314 or the x-ray source 2312 or both) to center the vertebral body at perfect AP and lateral angles based on the optimal 3D position and orientation of the vertebral body determined in step 2108. The determined optimal C-arm 2316 orientation and position for the vertebral body is then stored in the memory 410.

[0157] The optimal C-arm 2316 orientation and position determination of step 2110 can be performed at Fig.27A Partially seen. Fig.27A The model vertebra 2702 is shown aligned with the corresponding vertebra in the AP test image 2602 and the lateral test image 2604. It can be easily seen from the left panel 2720 showing the test AP image 2602 that the optimal position of the C-arm 2316 will include rotating it about 15 degrees clockwise and moving it down about half a spinal segment to center the vertebra. According to the right panel 2722 showing the lateral test image 2604, the optimal position of the C-arm 2316 will include rotating it about 10 degrees counterclockwise and moving it to the left about half a spinal segment to center the vertebra in the image.

[0158] The optimal C-arm 2316 orientation and position of the vertebral body is then stored in memory. In one embodiment, the orientation and position information used to capture one of the two images is stored. Capturing the other image is then just a matter of rotating the C-arm 2316 90 degrees. In an alternative embodiment, the orientation and position information used to capture both the AP and lateral images is stored. If there are any additional segments that have not been processed, steps 2106-2110 may be repeated.

[0159] In step 2112, the computer 408 displays the available spinal segments for optimal imaging on the display device 304 for the user to select, one example of which is shown in FIG. Fig.24A . For each segment, the display 304 displays two user input buttons 2402 and 2404. These buttons are used to position the imaging system 2300 to the ideal or optimal imaging position. Depending on the imaging device used, the positioning can be manual or automatic. Button 2402 is used to capture AP images, while box 2404 is used to capture lateral images. The user can select the image to be captured through an input device such as a mouse, touch screen, or keyboard. In one embodiment, the user can make a selection by touching the input button on the touch-sensitive screen of the display device 304.

[0160] In decision 2114 , the computer 408 determines whether the imaging device 2300 has automatic positioning capability. The automatic positioning capability allows the computer 408 to send position and orientation commands to move and rotate the C-arm 2316 of the imaging device 2300 in the optimal 3D position and orientation determined in step 2110 .

[0161] If it is determined that the imaging device 2300 has such capabilities, control passes to step 2116. In step 2116, the computer 408 sends the optimal 3D position and orientation of the C-arm 2316 to the imaging device.

[0162] In one embodiment, the computer 408 sends absolute position and orientation data to the imaging device 2300. This is possible if the imaging device 2300 knows its exact location within the operating room. In another embodiment, the computer 408 sends movement instructions to incrementally move and position the C-arm 2316, step by step. The computer 408 knows the relative position of the C-arm 2316 based on the initial registration of the imaging device 2300 to the patient. Based on the registration data and the optical markers 2310 on the gantry, the computer 408 can track the relative position and orientation of the C-arm 2316 with respect to the patient. Based on the tracking data and while tracking the markers, the computer can issue a series of incremental positioning commands to the imaging device 2300 until the optimal C-arm 2316 position and orientation is reached.

[0163] If it is determined in step 2114 that the imaging device does not have such automatic positioning capabilities (e.g., Fig. 12A If the user does not have an imaging system 1304 of the C-arm 1308, control passes to step 2118. In step 2118, the computer 408 graphically displays an indication of the position of the C-arm 1308 relative to the optimal position on the display device 304, and enables the user to move and orient the C-arm 1308. As the user moves the C-arm 1308, the graphical display on the display device 304 is continuously updated to show the user how close the C-arm 1308 is to its optimal position. The position of the C-arm 1308 may be tracked by optical markers 2202, 2204 on the calibration ring 2200 or some other trackable marker located on the C-arm. Fig.25 An example of a graphic display is shown.

[0164] The image on the left shows the xyz coordinates of the C-arm 1308. The dashed circle indicates the optimal position of the C-arm 1308. The center of the dashed circle indicates the optimal XY position, where the size of the dashed circle indicates the optimal Z position. The solid circle indicates the actual position of the C-arm 1308. As the user moves the C-arm 1308, the solid circle moves and changes its size to indicate its actual 3D (XYZ) position relative to the optimal position.

[0165] The right image shows the yaw-pitch-roll coordinates of the C-arm 1308. The dashed circle indicates the optimal orientation of the C-arm 1308. The center of the dashed circle indicates the optimal yaw-pitch position, where the size of the dashed circle indicates the optimal roll position. The solid circle indicates the actual position of the C-arm 1308 in terms of yaw, pitch, and roll. As the user moves the C-arm 1308, the solid circle moves and changes its size to indicate its 3D orientation relative to the optimal position.

[0166] Once the solid circle on both coordinates is aligned with the corresponding dashed circle, the imaging device 1304 is ready to capture the appropriate image. For example, if the user has selected L1-AP 2402, the imaging device 2300 captures the AP image. This can be done by actuating the appropriate button on the imaging device, or a command from the computer 408 can be sent to accomplish this.

[0167] Alternatively, once a spinal segment is selected, the computer 408 may send instructions to the imaging device 2300 to take both optimal AP and lateral images based on the stored optimal position and orientation that has been determined through steps 2102-2110.

[0168] In one embodiment, for each image captured and stored by the imaging device 2300, the computer 408 also stores the image in the memory 410 along with the position and orientation information of the C-arm 2316. This can be accomplished by optical markers 2310 and 2202-2204, or by internal positioning elements of the imaging device that control each axis and 3D position of the C-arm 2316, such as encoders in a motor.

[0169] As images are captured, additional spinal segments may appear in the newly acquired images. For example, when the best L1 images are captured, those images may include a new segment, such as L4. In one aspect of the invention, the computer 408 stores the newly acquired images (both AP and lateral) and their positions and orientations in the memory 410, and then if the new spinal segment is identified as a segment of interest in step 2104, steps 2102 to 2112 are repeated for this new segment.

[0170] In another aspect of the present invention, the computer 408 may optimize the best 3D position and orientation data that has been obtained. In the same example, the computer 408 may repeat steps 2102 to 2112 for L2 and L3 based on the newly acquired AP and lateral images. Since the images were taken based on the best 3D position and orientation data for L1, the images may also contain segments that are more optimally aligned for L2 and L3. Therefore, the optimized 3D and orientation positions of L2 and L3 may be more accurate than before.

[0171] In step 2112, the computer 408 displays on the display device 304 a graphical representation of input buttons 2410, 2412 for the new segment (eg, AP and lateral of L4), in addition to the input buttons 2402, 2404 for the old segment (eg, L1-L3).

[0172] As can be appreciated, the above method greatly reduces the setup time for positioning the x-ray imaging device in the operating room, because only two fluoroscopic images (a set of AP and lateral images) are required for each spinal segment, rather than 10 or more. This advantageous feature produces many benefits, including greatly reduced surgical time, greatly reduced radiation exposure to the patient and medical staff, and reduced surgical costs due to the reduced time required for the surgical procedure. Perhaps more importantly, because the present invention allows better images to be taken, it allows the physician to place the implant more accurately, which results in better surgical outcomes for the patient in many surgeries.

[0173] In another aspect of the invention, systems and methods are disclosed for identifying and segmenting anatomical structures from cone beam CT images rather than from reconstructed 3D volumetric data.

[0174] Cone beam CT reconstruction is a known method for creating 3D image volumes, where 2D x-ray shots or images taken from different known viewing angles are combined to form a 3D volume. Typically, x-rays are taken on a robotic rotating platform (e.g., see Fig.23 The images are taken on an imaging device 2300 in the image processing apparatus 2300, with each shot taken in small angular increments. For example, the imaging mechanism of the imaging device 2300 can rotate the x-ray emitter 2312 and collector 2314 360° around the patient, taking an x-ray image for each 1 degree increase. Knowing the orientation in which each x-ray was taken, the cone beam reconstruction software can combine the information from 360 separate 2D x-ray projections into a 3D volume. The process of reconstructing a volume from a set of shots is computationally intensive and, even with modern computer processors, typically requires at least 20 seconds to complete. The reconstruction software may also require that all shots be present before beginning image processing. In other words, processing may need to wait until the 360° rotation is complete.

[0175] According to one aspect of the invention, a method is contemplated that uses software on 2D samples from a series of shots acquired for segmentation purposes. By the time the rotation of the imaging device 2300 is complete, combining the segmentation statistics from multiple 2D viewing angles will provide fast and reliable automatic segmentation of the 3D volume.

[0176] Fig.28 A flow chart showing the workflow when using the 2D automatic segmentation software as part of the image control module 409 is shown. Figure 5 and Fig.21As discussed, the image control module 409 is stored in the memory 410 of the computer subsystem 504 for the surgical robot system. Fig.21 In addition to determining the 3D position and orientation of the imaging device for each spinal segment as discussed above, the imaging control software includes executing Fig.28 Additional software for the segmentation step of CT, as well as 3D volume reconstruction software for cone-beam CT.

[0177] In step 2800, the image control module 409 starts the 3D rotation of the cone beam CT imaging device 2300, which includes the initialization of the x-ray emitter, collector and other electronic components. In step 2802, the image control module 409 controls the C-arm 2316 of the imaging device 2300 to move to a suitable angular position and take an x-ray image. In the case of the first image, the imaging device 2300 can move the C-arm 2316 to a zero degree offset relative to the base of the device 2300 (e.g., perpendicular to the floor) to take the first image. The captured image is then transmitted to and stored in the memory 410. In subsequent imaging, the module 409 controls the C-arm 2316 to move to a predetermined angular position. For example, the C-arm 2316 can move one degree.

[0178] Because the orientation of the C-arm 2316 can be tracked by the tracking subsystem 532 via the tracking markers 2310, the orientation data for each image captured is recorded and transmitted to the memory 410 for storage.

[0179] In step 2804, module 409 determines whether the image just captured in step 2802 should be analyzed for segmentation. For example, module 409 determines whether the image is a multiple of N, where N is an integer. In one embodiment, N is at least 5. If N=5, it means that every 5th image (5 degrees offset from the previous image) will be analyzed.

[0180] Although only a selected set of 2D x-ray images are selected for processing to save time, the module 409 may perform the segmentation step 2806 on every 2D image from the c-arm 2316.

[0181] If the decision is yes, control passes to step 2806. In step 2806, module 409 performs an automatic segmentation method based on a previously stored model. The model can be enhanced or trained with deep learning or a neural network to train the computer model to identify structures within the image plane by comparing the image to a set of known images. In the case of the spine, segmentation can include determining the boundaries of each vertebra, its center (x, y, z position of the vertebral center), the 3D angular orientation of each subject, and the spinal segment of each subject.

[0182] When the automatic segmentation is complete, the method may also generate a set of confidence factors, which may include confidence levels for identifying the spinal segments, the center of each vertebral body in the image, and the 3D angular orientation of each body.

[0183] With respect to the confidence factors for the spinal segments, the confidence may reflect how certain the software is that the segment of each vertebra has been correctly determined.

[0184] With respect to the X, Y, Z coordinates of the center of the vertebra, the confidence may reflect the certainty of the center-finding method that the coordinates are correctly found values ​​within a certain tolerance (eg, 1 mm).

[0185] With respect to a unit vector describing a 3D orientation, the confidence may reflect how certain the orientation finding method is that it has found the orientation correctly within a certain tolerance (eg, 1 degree).

[0186] If the decision of step 2804 is no, control passes to step 2808. In step 2808, module 409 updates the display of the x-ray image with the segmentation and identification information obtained from step 2806. As the scan progresses, the display device 304 may display information, such as a progress bar, and may also display the last 2D shot on the screen, as well as adjust and display the latest labels on the 2D shot and in the area of ​​the screen where the volume will appear.

[0187] In step 2810, it is determined whether the 3D image rotation is complete. In one embodiment, the rotation is complete when all 360 images are taken at one degree intervals. If the rotation is not yet complete, control returns to step 2802, where the C-arm 2316 increases the predetermined angle interval and takes the next x-ray image.

[0188] If the decision in step 2810 is yes, control passes to step 2811. In step 2811, the segmentation and identification of each image in step 2806 is refined by analyzing all data obtained from step 2806.

[0189] In one embodiment, a weighting scheme is used. For the spinal segment finding method, the data listing might show that the average certainty of identifying the top segment is 85% L1, 75% L2, 75% L3, 75% L4, 70% L5, where each of those values ​​is taken as a simple average of 36 images. In this case, the method will name the top segment L1 because that is the best guess. There may be cases where there is no obvious answer. For example, there may be a case where, considering all the images, the average certainty score shows that the top segment is named L1 and also shows that the next segment below is named L1. In this case, when considering the top vertebra compared to the next below, the method can look at the surrounding individual images and see if the L1 certainty in any one shot is separated by a larger margin than all other segments. For example, considering the first five 2D x-ray images, assume that the top segment has the following certainty scores:

[0190] 1)85%L1, 75%L2, 74%L3, 76%L4, 70%L5

[0191] 2)85%L1, 76%L2, 75%L3, 75%L4, 69%L5

[0192] 3)86%L1, 75%L2, 76%L3, 75%L4, 70%L5

[0193] 4)85%L1, 74%L2, 75%L3, 75%L4, 70%L5

[0194] 5)84%L1, 75%L2, 75%L3, 74%L4, 71%L5

[0195] But further assume that the next segment below has the following certainty score:

[0196] 1)95%L1, 45%L2, 45%L3, 45%L4, 45%L5

[0197] 2)83%L1, 80%L2, 85%L3, 82%L4, 76%L5

[0198] 3)80%L1, 88%L2, 83%L3, 84%L4, 76%L5

[0199] 4)84%L1, 74%L2, 84%L3, 82%L4, 76%L5

[0200] 5)83%L1, 88%L2, 78%L3, 82%L4, 77%L5

[0201] In both data sets, the average of the 5 values ​​will be the same. However, in the second data set, L1 has a large separation from the competing names in the first shot (95% L1 vs. 45% L2 or other = 50% certainty difference), while in the first case the separation of certainty is small (9% to 11% certainty difference between the segment name being L1 and the other names). Therefore, the method can decide that the next segment down is more likely to be L1 than the first segment. Since it is known that the segments are numbered sequentially, with L1 above L2, L2 above L3, and so on, the method can consider all segments first and find the most likely overall segment, and then name the others based on their descending geometric significance.

[0202] However, for the center finding method, it may not matter what the segments of the vertebrae are named, and weighting may be used differently. As the rotation proceeds, focusing only on the top vertebra (regardless of what it is named), the algorithm may find the center (XYZ) with the following certainty for the first 7 shots: 95%, 92%, 75%, 25%, 25%, 75%, 95%.

[0203] Instead of averaging the X, Y, Z coordinates for the centers of the two shots that have only 25% certainty (even taking weighting into account), the method can exclude those two values ​​because they are below a chosen threshold (e.g., 70%). The other 5 images that remain can use a weighted average in order to take their certainty into account. The weighted average of these 5 remaining values ​​will be calculated using the usual method: sum of (weight*value) / sum of weight.

[0204] After step 2811, control then passes to step 2812. In step 2812, module 409 creates a 3D image volume 2900 using well-known cone beam reconstruction methods by combining all 2D x-ray images taken at known angular orientations different from the previous step (e.g., 360 images at 1 degree increments) (see Fig.29A ).

[0205] After 3D reconstruction, traditional methods would involve additional steps of segmentation and identification using the 3D volume just created, which is computationally very intensive.

[0206] However, in accordance with the principles of the present invention, the segmentation information has already been derived from the 2D image in a previous step. Therefore, the segmentation and identification information is fed into step 2812 and superimposed on the 3D image volume, as shown in FIG. Fig.29B As shown, a significant amount of time can be saved. Since cone beam rotation usually occurs in the operating room, saving surgical time is very important both for patient safety and surgical costs.

[0207] In step 2814, the updated 3D image volume 2910 with the segmentation information is displayed on the display device 304 for the physician to manipulate. The segmentation information may include a description of each vertebral body (e.g., see Fig.26 ), center position and boundary points of the 3D orientation (2902-2908) of each subject. Identification information may include the segments of each vertebra (L1-L4) and other bones or anatomical structures visible in the scan volume.

[0208] The graphical user interface portion of module 409 allows the physician to move the 3D image volume 2900 in six degrees of freedom to assist the physician in planning the implant.

[0209] Those of ordinary skill in the art will appreciate that while the present invention has been described with respect to vertebral bodies, the principles of the present invention may also be applied to any other tissue structure in the body, such as the knee, ankle, fingers, and the like.

[0210] Although several embodiments of the present invention have been disclosed in the foregoing description, it should be understood that many modifications and other embodiments of the present invention to which the present invention relates will benefit from the teachings presented in the foregoing description and the associated drawings. It should therefore be understood that the present invention is not limited to the specific embodiments disclosed above, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. It is also conceivable that features from one embodiment may be combined or used with features from different embodiments described herein. In addition, although specific terms are used here and in the subsequent claims, they are used only in a general and descriptive sense, and not for the purpose of limiting the described invention or the appended claims. The disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication is individually incorporated by reference herein. Various features and advantages of the present invention are set forth in the appended claims.

Claims

1. A method for identifying and segmenting anatomical structures from a cone beam CT image, the method comprising: receiving at least one x-ray image from a cone beam CT device that is a portion of a plurality of x-ray images acquired from a 360 degree scan of the patient, the at least one x-ray image containing at least one anatomical structure; identifying and segmenting the at least one anatomical structure contained in the x-ray image based on a stored anatomical structure model; as well as creating a 3D image volume from a plurality of x-ray images resulting from the 360 ​​degree scan; adding said identification and segmentation information derived from said at least one x-ray image to said created 3D image volume, wherein the receiving step includes receiving a set of x-ray images at regularly spaced angular orientations; as well as For each received x-ray image, determining a match confidence level for each of said received x-ray images; determining optimal recognition and segmentation information based on the confidence level, Wherein the step of determining optimal identification and segmentation information comprises determining a center of the anatomical structure by weighting the x-ray image based on the confidence level.

2. The method of claim 1, wherein the steps of identifying and segmenting include identifying and segmenting at least one vertebral body contained in the x-ray image.

3. The method of claim 1, wherein the step of determining optimal identification and segmentation information comprises excluding the x-ray images having a confidence level lower than a predetermined confidence level.

4. The method of claim 1, wherein the receiving step comprises receiving every Nth x-ray image from the 360 ​​degree scan, where N is equal to 5 or greater. 5 . The method of claim 4 , wherein the step of receiving each Nth x-ray image comprises receiving angular orientation information for each Nth x-ray image. The method of claim 1 , wherein the segmenting step comprises determining a center of the at least one anatomical structure.

7. The method of claim 6, wherein the step of determining the confidence level comprises determining a confidence level for the center of the at least one anatomical structure.

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