Surgical robotic system and method for using dithering to adjust transparency of an ar overlay

Abstract

A method and system provide intra-operative visualization in robotic-assisted and minimally invasive surgeries through augmented reality (AR) overlays using dithering techniques. The system integrates pre-operative and intra-operative imaging directly into the surgeon's field of view on a stereoscopic 3D screen without obstructing critical anatomical views. Traditional alpha blending methods for AR overlays are computationally intensive. The disclosed dithering approach alternately displays augmented and real pixels to create a semi-transparent effect, preserving the endoscopic view and ensuring patient safety. Transparency is dynamically adjustable using hand controllers, foot pedals, eye tracking, and voice commands. This innovation provides surgeons with critical subsurface anatomical information during procedures, reducing cognitive load and improving surgical outcomes by minimizing the risk of damaging critical structures. The system is compatible with existing surgical robotic platforms, offering an efficient and safe solution for integrating AR in surgical environments.

Description

SURGICAL ROBOTIC SYSTEM AND METHOD FOR USING DITHERING TO ADJUST TRANSPARENCY OF AN AR OVERLAYCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 660,634, filed June 17, 2024, the entire content of which is incorporated herein by reference.BACKGROUND

[0002] Surgical robotic systems are currently being used in a variety of surgical procedures, including minimally invasive medical procedures. Some surgical robotic systems include a surgeon console controlling a surgical robotic arm and a surgical instrument having an end effector (e.g., forceps or grasping instrument) coupled to and actuated by the robotic arm. In operation, the robotic arm is moved to a position over a patient and then guides the surgical instrument into a small incision via a surgical port or a natural orifice of a patient to position the end effector at a work site within the patient’s body.

[0003] Minimally invasive surgery (MIS) and robotic-assisted surgery (RAS) are becoming increasingly prevalent due to their advantages in reducing patient recovery time, minimizing surgical trauma, and enhancing surgical precision. These procedures often require the use of advanced imaging techniques such as pre-operative CT / MRI scans and intra-operative ultrasound (IOUS) to guide surgeons during operations. Traditional approaches involve displaying these images on separate monitors, requiring surgeons to shift their focus away from the surgical site, thereby increasing cognitive load and the potential for errors.

[0004] In certain surgical robotic systems, the primary visualization modality is stereoscopic endoscopic or laparoscopic imaging, which provides a surface view of the organs and tissues being operated on. However, these systems face significant challenges in visualizing subsurface structures such as tumors and critical anatomical features, which are useful for effective surgical planning and execution.

[0005] Traditional methods for integrating AR overlays with surgical video feeds typically employ alpha blending techniques. Alpha blending requires access to raw video feeds and involves resource-intensive operations, such as pixel value multiplication and addition across multiple render passes. This not only increases the computational burden but alsonecessitates dedicated hardware support, which is not always available in all surgical systems.

[0006] There is an unmet need for a system that can integrate additional imaging data, such as pre-operative scans and real-time intra-operative imaging, directly into the surgeon’s field of view without obstructing critical areas.SUMMARY

[0007] The present disclosure relates generally to the field of augmented reality (AR) in surgical procedures. More specifically, it pertains to a method and system for providing transparency in AR overlays using dithering techniques, particularly in RAS and MIS. This present disclosure aims to provide visualization as an AR overlay in the safest way (i.e., without obstructing laparoscopic video feed) that is useful to surgical goal of cancer resection. MIS and RAS require the surgeon to precisely locate the tumor and critical structures during the surgical procedure. The main modality used during surgical procedures is stereo laparoscopic imaging. This imaging modality shows the organ surface during the surgical procedure. Surgical resection requires precise localization of tumor and critical structures buried deep inside the organ undergoing resection. In many surgical indications like partial nephrectomy, hepatic resection, myomectomy, etc., use of intra-operative imaging sensors, like intra-operative ultrasound (IOUS), is used. In many surgical indications like radical prostatectomy, partial nephrectomy, hepatic resection, etc. the use of pre-operative imaging and digital twin 3D models (i.e., organ and tissue models computed from the pre-operative imaging) may also be used. There is an unmet need of showing the information from external video sources, pre-operative imaging and digital twin 3D.

[0008] The disclosed system and method provide for displaying an AR overlay to enhance surgeon’s vision during the procedure. In RAS platforms, there is a need to see the additional visualizations (e.g., intra-operative ultrasound, pre-operative imaging and digital twin 3D models) on the main 3D screen without turning their head and taking the gaze away from the S3D screen. Finally, there is an unmet need to display the IOUS images on S3D to satisfy two opposite constraints. Another need is to reduce the cognitive burden on surgeons to help them register the surface view of anatomy (from laparoscopic images) to the sub-surface critical structures and tumor (from IOUS images). A further need is to avoid obscuring the endoscope view to ensure patient safety. This disclosure proposes an innovative solution forintra-operative navigational assistance by rendering AR overlay of IOUS images on main 3D screen in a safe and effective way.

[0009] The present disclosure provides a method of visualizing additional pre-operative imaging, digital twin 3D models, and intra-operative imaging as an AR overlay. The AR overlays are generated using a dithering-based process to achieve realistic transparency in hardware-constrained platforms that lack dedicated alpha blending hardware. In addition, a user interface mechanism is provided to identify the optimal placement and transparency control in order to satisfy the safe visualization requirements.

[0010] According to one embodiment of the present disclosure, a method for generating a transparent augmented reality (AR) overlay in a surgical robotic system is disclosed. The method includes receiving an image for use as the AR overlay and receiving a video feed from a laparoscopic camera. The method also includes selecting a location for the AR overlay on a display screen including pixels showing the video feed and generating the AR overlay using a dithering process, where the dithering process replaces a portion of the pixels showing the video feed with the image to create a semi-transparent effect. The method further includes displaying the dithered AR overlay on the display screen along with a laparoscopic video feed and adjusting the transparency of the AR overlay dynamically based on user input and surgical context.

[0011] Implementations of the above embodiment may include one or more of the following features. According to one aspect of the above embodiment, the image for the AR overlay may be obtained from pre-operative imaging modalities, which may be one of computed tomography (CT) or magnetic resonance imaging (MRI). The image for the AR overlay may be obtained from intra-operative imaging modalities, which may be one of ultrasound, gamma probe, or Raman spectroscopy. The GUI may include a slider to control one of transparency or opacity of the AR overlay. The dithering process may further include rendering a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying. The method may also include adjusting transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay. The transparency of the AR overlay may be adjusted based on its position on the display screen, with a higher transparency in the center of the display screen. Adjusting the transparency may include increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when theoverlay is positioned over non-critical areas. Transparency of the AR overlay may be increased when positioned in the protected zone.

[0012] According to another embodiment of the present disclosure, a surgical robotic system is disclosed. The surgical robotic system includes a display screen configured to output a video feed of a surgical site from a laparoscopic camera. The system also includes an imaging device configured to capture images of the surgical site. The system further includes a processing device configured to receive an image for generating a transparent augmented reality (AR) overlay; receive a video feed from a laparoscopic camera; select a location for the AR overlay on a display screen including pixels showing the video feed; generate the AR overlay using a dithering process, where the dithering process replaces a portion of the pixels showing the video feed with the image to create a semi-transparent effect; display the dithered AR overlay on the display screen along with a laparoscopic video feed; and adjust the transparency of the AR overlay dynamically based on user input and surgical context.

[0013] Implementations of the above embodiment may include one or more of the following features. According to one aspect of the above embodiment, the imaging device is a pre- operative imaging device may be one of computed tomography (CT) and magnetic resonance imaging (MRI). The imaging device may be an intra-operative imaging device, which may be one of ultrasound, gamma probe, and Raman spectroscopy. The display screen may be configured to output a graphical user interface (GUI) to control the transparency of the AR overlay, where the GUI includes a slider to control one of transparency or opacity of the AR overlay. The processing device may be further configured to render a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying. The processing device may be further configured to adjust transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay. The transparency of the AR overlay may be adjusted based on its position on the display screen, with a higher transparency in the center of the display screen. The processing device may be further configured to adjust the transparency by increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when the overlay is positioned over non-critical areas. The processing device may be also configured to divide the display screen intoprotected and unprotected zones, where transparency of the AR overlay is increased when positioned in the protected zone.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments of the present disclosure are described herein with reference to the drawings wherein:

[0015] FIG. 1 is a perspective view of a surgical robotic system including a control tower, a console, and one or more surgical robotic arms each disposed on a mobile cart according to an embodiment of the present disclosure;

[0016] FIG. 2 is a perspective view of a surgical robotic arm of the surgical robotic system of FIG. 1 according to an embodiment of the present disclosure;

[0017] FIG. 3 is a perspective view of a mobile cart having a setup arm with the surgical robotic arm of the surgical robotic system of FIG. 1 according to an embodiment of the present disclosure;

[0018] FIG. 4 is a schematic diagram of a computer architecture of the surgical robotic system of FIG. 1 according to an embodiment of the present disclosure;

[0019] FIG. 5 is a plan schematic view of the surgical robotic system of FIG. 1 positioned about a surgical table according to an embodiment of the present disclosure;

[0020] FIG. 6 is a schematic diagram of a system for determining phases of a surgical procedure according to an embodiment of the present disclosure;

[0021] FIG. 7 is a flow chart of a method for controlling transparency of an AR overlay using dithering according to an embodiment of the present disclosure;

[0022] FIG. 8 is a screenshot of a graphical user interface for controlling transparency of the AR overlay according to an embodiment of the present disclosure;

[0023] FIG. 9A is a screenshot of an alpha-blending technique to combine two images; and

[0024] FIG. 9B is a screenshot of a dithering technique to combine two images according to an embodiment of the present disclosure.DETAILED DESCRIPTION

[0025] Embodiments of the presently disclosed surgical robotic system are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “coupledto” denotes a connection between components, which may be direct or indirect (i.e., through one or more components) and may be electronic, electrical, mechanical, or combinations thereof.

[0026] With reference to FIG. 1, a surgical robotic system 10 includes a control tower 20, which is connected to all the components of the surgical robotic system 10 including a surgeon console 30 and one or more mobile carts 60. Each of the mobile carts 60 includes a robotic arm 40 having a surgical instrument 50 removably coupled thereto. The robotic arms 40 also couple to the mobile carts 60. The robotic system 10 may include any number of mobile carts 60 and / or robotic arms 40.

[0027] The surgical instrument 50 is configured for use during minimally invasive surgical procedures. In embodiments, the surgical instrument 50 may be configured for open surgical procedures. In further embodiments, the surgical instrument 50 may be an electrosurgical or ultrasonic instrument, such as a forceps configured to seal tissue by compressing tissue between jaw members and applying electrosurgical current or ultrasonic vibrations via an ultrasonic transducer to the tissue. In yet further embodiments, the surgical instrument 50 may be a surgical stapler including a pair of jaws configured to grasp and clamp tissue while deploying a plurality of tissue fasteners, e.g., staples, and cutting stapled tissue. In yet further embodiments, the surgical instrument 50 may be a surgical clip applier including a pair of jaws configured apply a surgical clip onto tissue. The system also includes an electrosurgical generator 57 configured to output electrosurgical (e.g., monopolar or bipolar) or ultrasonic energy in a variety of operating modes, such as coagulation, cutting, sealing, etc. Suitable generators include a Valleylab™ FT10 Energy Platform available from Medtronic of Minneapolis, MN.

[0028] One of the robotic arms 40 may include a laparoscopic camera 51 configured to capture video of the surgical site. The laparoscopic camera 51 may be a stereoscopic camera configured to capture two side-by-side (i.e., left and right) images of the surgical site to produce a video stream of the surgical scene. The laparoscopic camera 51 is coupled to an image processing device 56, which may be disposed within the control tower 20. The image processing device 56 may be any computing device configured to receive the video feed from the laparoscopic camera 51 and output the processed video stream.

[0029] The surgeon console 30 includes a first, i.e., surgeon, screen 32, which displays a video feed of the surgical site provided by camera 51 of the surgical instrument 50 disposedon the robotic arm 40, and a second screen 34, which displays a user interface for controlling the surgical robotic system 10. The first screen 32 and second screen 34 may be touchscreens allowing for displaying various graphical user inputs. The first screen 32 may be a 3D screen.

[0030] The surgeon console 30 also includes a plurality of user interface devices, such as foot pedals 36 and a pair of hand controllers 38a and 38b which are used by a user to remotely control robotic arms 40. The surgeon console further includes an armrest 33 used to support clinician’s arms while operating the hand controllers 38a and 38b.

[0031] The control tower 20 includes a screen 23, which may be a touchscreen, and outputs on the graphical user interfaces (GUIs). The control tower 20 also acts as an interface between the surgeon console 30 and one or more robotic arms 40. In particular, the control tower 20 is configured to control the robotic arms 40, such as to move the robotic arms 40 and the corresponding surgical instrument 50, based on a set of programmable instructions and / or input commands from the surgeon console 30, in such a way that robotic arms 40 and the surgical instrument 50 execute a desired movement sequence in response to input from the foot pedals 36 and the hand controllers 38a and 38b. The foot pedals 36 may be used to enable and lock the hand controllers 38a and 38b, repositioning camera movement and electrosurgical activation / deactivation. In particular, the foot pedals 36 may be used to perform a clutching action on the hand controllers 38a and 38b. Clutching is initiated by pressing one of the foot pedals 36, which disconnects (i.e., prevents movement inputs) the hand controllers 38a and / or 38b from the robotic arm 40 and corresponding instrument 50 or camera 51 attached thereto. This allows the user to reposition the hand controllers 38a and 38b without moving the robotic arm(s) 40 and the instrument 50 and / or camera 51. This is useful when reaching control boundaries of the surgical space.

[0032] Each of the control tower 20, the surgeon console 30, and the robotic arm 40 includes a respective computer 21, 31, 41. The computers 21 , 31 , 41 are interconnected to each other using any suitable communication network based on wired or wireless communication protocols. The term “network,” whether plural or singular, as used herein, denotes a data network, including, but not limited to, the Internet, Intranet, a wide area network, or a local area network, and without limitation as to the full scope of the definition of communication networks as encompassed by the present disclosure. Suitable protocols include, but are not limited to, transmission control protocol / intemet protocol (TCP / IP), datagramprotocol / intemet protocol (UDP / IP), and / or datagram congestion control protocol (DC). Wireless communication may be achieved via one or more wireless configurations, e.g., radio frequency, optical, Wi-Fi, Bluetooth (an open wireless protocol for exchanging data over short distances, using short length radio waves, from fixed and mobile devices, creating personal area networks (PANs), ZigBee® (a specification for a suite of high level communication protocols using small, low-power digital radios based on the IEEE 122.15.4-1203 standard for wireless personal area networks (WPANs)).

[0033] The computers 21, 31, 41 may include any suitable processor (not shown) operably connected to a memory (not shown), which may include one or more of volatile, nonvolatile, magnetic, optical, or electrical media, such as read-only memory (ROM), random access memory (RAM), electrically erasable programmable ROM (EEPROM), non-volatile RAM (NVRAM), or flash memory. The processor may be any suitable processor (e.g., control circuit) adapted to perform the operations, calculations, and / or set of instructions described in the present disclosure including, but not limited to, a hardware processor, a field programmable gate array (FPGA), a digital signal processor (DSP), a central processing unit (CPU), a microprocessor, and combinations thereof. Those skilled in the art will appreciate that the processor may be substituted for by using any logic processor (e.g., control circuit) adapted to execute algorithms, calculations, and / or set of instructions described herein.

[0034] With reference to FIG. 2, each of the robotic arms 40 may include a plurality of links 42a, 42b, 42c, which are interconnected at joints 44a, 44b, 44c, respectively. Other configurations of links and joints may be utilized as known by those skilled in the art. The joint 44a is configured to secure the robotic arm 40 to the mobile cart 60 and defines a first longitudinal axis. With reference to FIG. 3, the mobile cart 60 includes a lift 67 and a setup arm 61, which provides a base for mounting the robotic arm 40. The lift 67 allows for vertical movement of the setup arm 61. The mobile cart 60 also includes a screen 69 for displaying information pertaining to the robotic arm 40. In embodiments, the robotic arm 40 may include any type and / or number of joints.

[0035] The setup arm 61 includes a first link 62a, a second link 62b, and a third link 62c, which provide for lateral maneuverability of the robotic arm 40. The links 62a, 62b, 62c are interconnected at joints 63a and 63b, each of which may include an actuator (not shown) for rotating the links 62b and 62b relative to each other and the link 62c. In particular, thelinks 62a, 62b, 62c are movable in their corresponding lateral planes that are parallel to each other, thereby allowing for extension of the robotic arm 40 relative to the patient (e.g., surgical table). In embodiments, the robotic arm 40 may be coupled to the surgical table (not shown). The setup arm 61 includes controls 65 for adjusting movement of the links 62a, 62b, 62c as well as the lift 67. In embodiments, the setup arm 61 may include any type and / or number of joints.

[0036] The third link 62c may include a rotatable base 64 having two degrees of freedom. In particular, the rotatable base 64 includes a first actuator 64a and a second actuator 64b. The first actuator 64a is rotatable about a first stationary arm axis which is perpendicular to a plane defined by the third link 62c and the second actuator 64b is rotatable about a second stationary arm axis which is transverse to the first stationary arm axis. The first and second actuators 64a and 64b allow for full three-dimensional orientation of the robotic arm 40.

[0037] The actuator 48b of the joint 44b is coupled to the joint 44c via the belt 45 a, and the joint 44c is in turn coupled to the joint 46b via the belt 45b. Joint 44c may include a transfer case coupling the belts 45a and 45b, such that the actuator 48b is configured to rotate each of the links 42b, 42c and a holder 46 relative to each other. More specifically, links 42b, 42c, and the holder 46 are passively coupled to the actuator 48b which enforces rotation about a pivot point “P” which lies at an intersection of the first axis defined by the link 42a and the second axis defined by the holder 46. In other words, the pivot point “P” is a remote center of motion (RCM) for the robotic arm 40. Thus, the actuator 48b controls the angle 0 between the first and second axes allowing for orientation of the surgical instrument 50. Due to the interlinking of the links 42a, 42b, 42c, and the holder 46 via the belts 45a and 45b, the angles between the links 42a, 42b, 42c, and the holder 46 are also adjusted to achieve the desired angle 0. In embodiments, some or all of the joints 44a, 44b, 44c may include an actuator to obviate the need for mechanical linkages.

[0038] The joints 44a and 44b include an actuator 48a and 48b configured to drive the joints 44a, 44b, 44c relative to each other through a series of belts 45a and 45b or other mechanical linkages such as a drive rod, a cable, or a lever and the like. In particular, the actuator 48a is configured to rotate the robotic arm 40 about a longitudinal axis defined by the link 42a.

[0039] With reference to FIG. 2, the holder 46 defines a second longitudinal axis and configured to receive an instrument drive unit (IDU) 52 (FIG. 1). The IDU 52 is configured to couple to an actuation mechanism of the surgical instrument 50 and the camera 51 and isconfigured to move (e.g., rotate) and actuate the instrument 50 and / or the camera 51. IDU 52 transfers actuation forces from its actuators to the surgical instrument 50 to actuate components an end effector 49 of the surgical instrument 50. The holder 46 includes a sliding mechanism 46a, which is configured to move the IDU 52 along the second longitudinal axis defined by the holder 46. The holder 46 also includes a joint 46b, which rotates the holder 46 relative to the link 42c. During laparoscopic procedures, the instrument 50 may be inserted through a laparoscopic access port 55 (FIG. 3) held by the holder 46. The holder 46 also includes a port latch 46c for securing the access port 55 to the holder 46 (FIG. 2).

[0040] The robotic arm 40 also includes a plurality of manual override buttons 53 (FIG. 1) disposed on the IDU 52 and the setup arm 61, which may be used in a manual mode. The user may press one or more of the buttons 53 to move the component associated with the button 53.

[0041] With reference to FIG. 4, each of the computers 21, 31, 41 of the surgical robotic system 10 may include a plurality of controllers, which may be embodied in hardware and / or software. The computer 21 of the control tower 20 includes a controller 21a and safety observer 2 lb. The controller 21a receives data from the computer 31 of the surgeon console 30 about the current position and / or orientation of the hand controllers 38a and 38b and the state of the foot pedals 36 and other buttons. The controller 21a processes these input positions to determine desired drive commands for each joint of the robotic arm 40 and / or the IDU 52 and communicates these to the computer 41 of the robotic arm 40. The controller 2 la also receives the actual joint angles measured by encoders of the actuators 48a and 48b and uses this information to determine force feedback commands that are transmitted back to the computer 31 of the surgeon console 30 to provide haptic feedback through the hand controllers 38a and 38b. The safety observer 21b performs validity checks on the data going into and out of the controller 21a and notifies a system fault handler if errors in the data transmission are detected to place the computer 21 and / or the surgical robotic system 10 into a safe state.

[0042] The controller 21a is coupled to a storage 22a, which may be non-transitory computer-readable medium configured to store any suitable computer data, such as software instructions executable by the controller 21a. The controller 21a also includes transitory memory 22b for loading instructions and other computer readable data during execution ofthe instructions. In embodiments, other controllers of the system 10 include similar configurations.

[0043] The computer 41 includes a plurality of controllers, namely, a main cart controller 41a, a setup arm controller 41b, a robotic arm controller 41c, and an instrument drive unit (IDU) controller 4 Id. The main cart controller 41a receives and processes joint commands from the controller 21a of the computer 21 and communicates them to the setup arm controller 41b, the robotic arm controller 41c, and the IDU controller 41d. The main cart controller 41a also manages instrument exchanges and the overall state of the mobile cart 60, the robotic arm 40, and the IDU 52. The main cart controller 41a also communicates actual joint angles back to the controller 21a.

[0044] Each of joints 63a and 63b and the rotatable base 64 of the setup arm 61 are passive joints (i.e., no actuators are present therein) allowing for manual adjustment thereof by a user. The joints 63a and 63b and the rotatable base 64 include brakes that are disengaged by the user to configure the setup arm 61. The setup arm controller 41b monitors slippage of each of joints 63a and 63b and the rotatable base 64 of the setup arm 61, when brakes are engaged or can be freely moved by the operator when brakes are disengaged, but do not impact controls of other joints. The robotic arm controller 41c controls each joint 44a and 44b of the robotic arm 40 and calculates desired motor torques required for gravity compensation, friction compensation, and closed loop position control of the robotic arm 40. The robotic arm controller 41c calculates a movement command based on the calculated torque. The calculated motor commands are then communicated to one or more of the actuators 48a and 48b in the robotic arm 40. The actual joint positions are then transmitted by the actuators 48a and 48b back to the robotic arm controller 41c.

[0045] The IDU controller 4 Id receives desired joint angles for the surgical instrument 50, such as wrist and jaw angles, and computes desired currents for the motors in the IDU 52. The IDU controller 4 Id calculates actual angles based on the motor positions and transmits the actual angles back to the main cart controller 41a.

[0046] With reference to FIG. 5, the surgical robotic system 10 is set up around a surgical table 90. The system 10 includes mobile carts 60a-d, which may be numbered “1” through “4.” During setup, each of the carts 60a-d are positioned around the surgical table 90. Position and orientation of the carts 60a-d depends on a plurality of factors, such as placement of a plurality of access ports 55a-d, which in turn, depends on the surgery beingperformed. Once the port placement is determined, the access ports 55a-d are inserted into the patient, and carts 60a-d are positioned to insert instruments 50 and the laparoscopic camera 51 into corresponding ports 55a-d.

[0047] During use, each of the robotic arms 40a-d is attached to one of the access ports 55a- d that is inserted into the patient by attaching the latch 46c (FIG. 2) to the access port 55 (FIG. 3). The IDU 52 is attached to the holder 46, followed by the SIM 43 being attached to a distal portion of the IDU 52. Thereafter, the instrument 50 is attached to the SIM 43. The instrument 50 is then inserted through the access port 55 by moving the IDU 52 along the holder 46. The SIM 43 includes a plurality of drive shafts configured to transmit rotation of individual motors of the IDU 52 to the instrument 50 thereby actuating the instrument 50. In addition, the SIM 43 provides a sterile barrier between the instrument 50 and the other components of robotic arm 40, including the IDU 52. The SIM 43 is also configured to secure a sterile drape (not shown) to the IDU 52.

[0048] A surgical procedure may include multiple phases, and each phase may include one or more surgical actions. As used herein, the term “phase” represents a surgical event that is composed of a series of steps (e.g., closure). A “surgical action” may include an incision, a compression, a stapling, a clipping, a suturing, a cauterization, a sealing, or any other such actions performed to complete a phase in the surgical procedure. A “step” refers to the completion of a named surgical objective (e.g., hemostasis). During each step, certain surgical instruments 50 (e.g., forceps) are used to achieve a specific objective by performing one or more surgical actions.

[0049] With reference to FIG. 6, the surgical robotic system 10 may include a machine learning (MU) processing system 310 that processes the surgical data using one or more MU models to identify one or more features, such as surgical phase, instrument, anatomical structure, etc., in the surgical data. The MU processing system 310 includes a MU training system 325, which may be a separate device (e.g., server) that stores its output as one or more trained MU models 330. The MU models 330 are accessible by a MU execution system 340. The MU execution system 340 may be separate from the MU training system 325, namely, devices that “train” the models are separate from devices that “infer,” i.e., perform real-time processing of surgical data using the trained MU models 330.

[0050] System 10 includes a data reception system 305 that collects surgical data, including the video data and surgical instrumentation data. The data reception system 305 can includeone or more devices (e.g., one or more user devices and / or servers) located within and / or associated with a surgical operating room and / or control center. The data reception system 305 can receive surgical data in real-time, i.e., as the surgical procedure is being performed.

[0051] The ML processing system 310, in some examples, may further include a data generator 315 to generate simulated surgical data, such as a set of virtual images, or record the video data from the image processing device 56, to train the ML models 330 as well as other sources of data, e.g., user input, arm movement, etc. Data generator 315 can access (read / write) a data store 320 to record data, including multiple images and / or multiple videos.

[0052] The ML processing system 310 also includes a phase detector 350 that uses the ML models to identify a phase within the surgical procedure. Phase detector 350 uses a particular procedural tracking data structure 355 from a list of procedural tracking data structures. Phase detector 350 selects the procedural tracking data structure 355 based on the type of surgical procedure that is being performed. In one or more examples, the type of surgical procedure is predetermined or input by user. The procedural tracking data structure 355 identifies a set of potential phases that may correspond to a part of the specific type of surgical procedure.

[0053] In some examples, the procedural tracking data structure 355 may be a graph that includes a set of nodes and a set of edges, with each node corresponding to a potential phase. The edges may provide directional connections between nodes that indicate (via the direction) an expected order during which the phases will be encountered throughout an iteration of the surgical procedure. The procedural tracking data structure 355 may include one or more branching nodes that feed to multiple next nodes and / or may include one or more points of divergence and / or convergence between the nodes. In some instances, a phase indicates a procedural action (e.g., surgical action) that is being performed or has been performed and / or indicates a combination of actions that have been performed. In some instances, a phase relates to a biological state of a patient undergoing a surgical procedure. For example, the biological state may indicate a complication (e.g., blood clots, clogged arteries / veins, etc.), pre-condition (e.g., lesions, polyps, etc.). In some examples, the ML models 330 are trained to detect an “abnormal condition,” such as hemorrhaging, arrhythmias, blood vessel abnormality, etc.

[0054] The phase detector 350 outputs the phase prediction associated with a portion of the video data that is analyzed by the ML processing system 310. The phase prediction is associated with the portion of the video data by identifying a start time and an end time of the portion of the video that is analyzed by the ML execution system 340. The phase prediction that is output may include an identity of a surgical phase as detected by the phase detector 350 based on the output of the ML execution system 340. Further, the phase prediction, in one or more examples, may include identities of the structures (e.g., instrument, anatomy, etc.) that are identified by the ML execution system 340 in the portion of the video that is analyzed. The phase prediction may also include a confidence score of the prediction. Other examples may include various other types of information in the phase prediction that is output. The predicted phase may be used by the controller 21 a to determine when to control transparency and other parameters of AR overlay as described below.

[0055] FIG. 7 shows a method 400 for generating a transparent AR overlay on a laparoscopic video feed using dithering. The method may be embodied as software instructions stored in storage 22a and / or memory 22b that are executable by a processor (e.g., controller 21a). With reference to FIG. 8, the display screen 32 shows a laparoscopic video feed 500 including an AR overlay 502. At step 402, the image that is to be displayed as the AR overlay 502 is provided to the system 10, e.g., downloaded from a server, uploaded via a removable storage device into storage 22a, etc. The image used as the AR overlay 502 may be obtained using any suitable preoperative or intraoperative imaging modality and may include a digital twin 3D tissue and organ models constructed therefrom. Preoperative imaging modalities include computed tomography (CT), magnetic resonance imaging (MRI), etc. Intraoperative imaging modalities ultrasound, gamma probe, Raman spectroscopy, gamma probe, etc.

[0056] The AR overlay 502 may be an ultrasound fan-beam outline rendered under the ultrasound probe to represent the registration of the IOUS slice with the laparoscopic video feed 500. This ultrasound fan beam outline may be either opaque or semi-transparent or dithered to show the anatomy from endoscope image. In another embodiment, the AR overlay 502 may include the raw ultrasound image rendered under the ultrasound probe to represent the registration of the IOUS slice with endoscope surface view and show the ultrasound image content. This ultrasound raw image may be either opaque or semitransparent or dithered to show the anatomy from endoscope image.

[0057] In another embodiment, the AR overlay 502 may include the raw ultrasound image with Al-based semantic segmented mask overlay IOUS images rendered under the ultrasound probe to represent the registration of the IOUS slice with the laparoscopic video feed 500 and show the ultrasound image content along with Al-based segmentation. This Al-based semantic segmented mask overlay IOUS image may be either opaque or semitransparent or dithered to show the anatomy from endoscope image. In a further embodiment, the AR overlay 502 may include the IOUS images and may be displayed in any portion of the screen, e.g., a comer. The placement can be preset from surgeon and procedure specific preferences as described below.

[0058] At step 404, location of the AR overlay 502 on the video feed 500 is selected which may be done automatically by the controller 21a and / or by the user. Registration includes matching a plurality of landmarks or other features on the image forming the AR overlay 502 with counterpart features in the feed 500. In addition, the AR overlay 502 may be placed in a position on the screen 32 based on user selection or preset option or extending from an ultrasonic probe as shown in FIG. 8.

[0059] At step 406, the AR overlay 502 is generated and is displayed along with the video feed 500 as shown in FIG. 8. The AR overlay 502 is displayed in a dithered manner. FIGS. 9A and 9B show dithering (FIG. 9B) as compared to alpha blending (FIG. 9A). Alpha blending transparency utilizes the raw video feed to blend the pixel values with AR overlay 502, so this approach only works when AR overlay application has access to raw sensor video feed. Alpha blending is also a resource-heavy operation as it requires multiplication and addition of pixel values with multiple render passes using specialized hardware.

[0060] Dithering in graphics is a technique employed to simulate color depth in images that have a limited color palette. This method arranges pixels of different colors in specific patterns, which blend together when viewed from a distance to create the illusion of intermediate colors that are not actually present in the palette. For instance, by placing black and white pixels next to each other in a certain arrangement, dithering can produce the appearance of gray shades, without actually mixing or blending the colors for the individual pixel. Suitable dithering algorithms include Floyd-Steinberg dithering, which diffuses the quantization error to neighboring pixels, and Ordered dithering, which employs a fixed pattern of pixel intensities.

[0061] In the context of AR overlays in surgical procedures, dithering is used to combine the image as the AR overlay 502 seamlessly with the real-time video feed 500. This method creates a semi-transparent effect, allowing the augmented content to overlay without fully obscuring critical real-world visual information. This is particularly advantageous in surgical settings, where maintaining a clear view of the operative field is essential for patient safety and effective surgical manipulation, and where resource-intensive alpha blending is not feasible due to hardware constraints.

[0062] The dithering process includes initially creating a virtual scene with augmented information based on selected imaging modality. All pixels where no augmented information is to be shown are rendered as pass-through (i.e., chroma-keyed) with the video feed 500. Chroma key compositing, or chroma keying, is a visual-effects and postproduction technique for compositing (layering) two or more images or video streams together based on color hues (chroma range). All pixels where augmented information is to be shown are rendered with dithering fraction. Initial dithering fraction may be set to 50%, which is user configurable. For example, at 50% dithering, every other pixel (e.g., half of pixels covered by the AR overlay 502) is rendered with augmented information, while every other pixel (e.g., other half of pixels covered by the AR overlay 502) is rendered as pass- through (chroma keyed). The system 10 then mixes laparoscopic video feed 500 and virtual scene of the AR overlay 502 using dithering. Thus, the AR overlay 502 is created using dithered pixels, without performing any blending calculations, i.e., without pixel multiplication and addition, a pixel is either provided from the video feed 500 or the image used as the AR overlay 502. The full scene, the AR overlay 502 and the video feed 500 frame are rendered at once.

[0063] The system 10 implements AR overlay as chroma key with dithering. The system 10 may implement a range of color values in the YUV or any other color space as chroma keys. The AR overlay visualization can render individual pixels, groups of pixels as subregions and groups of subregions as zones either inside or outside the chroma key range. This method of rendering individual pixels values as either inside or outside the chroma key range is also referred to as dithering.

[0064] If a pixel is rendered with a value in the chroma key range, that pixel value will be replaced with the laparoscopic video feed not providing an AR overlay at that pixel. If a pixel is rendered with a value outside the chroma key range, that pixel value will overwritethe laparoscopic video feed at that pixel providing the AR overlay at that pixel. Transparency of the AR overlay can be controlled on a subregion or zone level. In addition to chroma key, dithering may be implemented for a fixed location of AR overlay by specifying which pixels would be replaced (e.g., in an XY location for each pixel).

[0065] At step 408, selections for the dithering process are received via a GUI 504 or any other inputs, such as buttons of handle controllers 38a and 38b, foot pedals, eye tracking, voice commands, mouse or keyboard, bedside assist controls (e.g., headset or keypad). The GUI 504 may include an element (e.g., slider, drop down menu, etc.) to adjust the transparency of the AR overlay 502. The slider may be moved from a 0% (e.g., full transparency) to 100 % (e.g., full opacity).

[0066] The GUI 504 may be displayed on any of the display screens 32 and 34 and may be a touch-based interface with one of the screens 32 and 34 being a touchscreen. In one embodiment, the GUI 504 lets the user position the non-laparoscopic imaging modality, e.g., ultrasound image, on any portion, e.g., comer, of the screen 32. The location can be implemented with a preset surgeon and procedure-specific setting, e.g., bottom right comer of the screen.

[0067] The GUI 504 may also include elements for controlling the size of the external imaging modality, which can be implemented with a preset surgeon and procedure-specific setting, e.g., 1 / 16th of the horizontal and vertical size of the full screen. The GUI 504 may also implement a toggle for turning the AR overlay on / off The GUI 504 may also implement a toggle showing or hiding additional AR overlay on top of the second video feed such as the Al-based segmentation of the ultrasound.

[0068] In further embodiments, transparency of dithering may be adjusted for different regions of the endoscope view based on critical structures (e.g., highly transparent region) and tools (e.g., highly opaque region). The dithering amount may also be adjusted based on the output of the phase detector 350. The transparency may be adjusted for different regions of the camera view based on critical structures, where critical structures are displayed using a highly transparent region (e.g., 10% dithering) and tools and instmments 50 using a highly opaque region (e.g., 90% dithering).

[0069] At step 410, the dithering level is adjusted based on the inputs at step 408. The controller 21a may adjust the level of dithering based on safety constraints provided by the phase detector 350 and / or detection of objects and critical structures using Al-basedsegmentation. The transparency of the AR overlay 502 is automatically increased when critical structures are detected, and the AR overlay 502 is positioned over them. Conversely, opacity of the AR overlay 502 is automatically decreased when critical structures are detected, and the AR overlay 502 is positioned over them.

[0070] In embodiments, transparency of the AR overlay 502 may be adjusted based on its position on the display screen 32, which may be done based on the distance between the center of the AR overlay 502 and the center of the display screen 32. Additionally, the display area may be subdivided into protected and unprotected zones, where the center of the laparoscope feed is protected zone and only AR overlay 502 with highly transparent visualization is shown in that area. This allows the surgeon to always have a view of the anatomy from laparoscope. The method is also safe to use with energy instrument, whereby any opaque overlays are disabled or made highly transparent when an energy instrument is present in the scene. The transparency of the AR overlay 502 when placed over critical structures and tumor may also be increased regardless which part of screen they are located based on Al-based segmentation of critical structures and tumor, thereby disregarding the area of the screen as the guiding parameter for transparency selection when critical structures are present in the scene.

[0071] Thus, transparency of the AR overlay 502 may be adaptively adjusted based on whether the overlay is present in the protected vs unprotected zones, based on the phase of the procedure, whether or not critical structures are in view, whether energy instruments are active or in the view or not, and the like. Furthermore, the method can adaptively change the dithering -based transparency at a subregion level within zones. A subregion can be as large as a zone or as small as a group of pixels, e.g., 2x2 pixels. With this approach, the transparency of certain parts of the AR overlay 502 can be changed granularly. For example, for a 3D model AR overlay, the transparency of the pixels showing the organ capsule can be adjusted to a very low opacity, e.g., 20%, to show the organ capsule AR overlay in a highly transparent way. In this setting, transparency of the pixels showing the internal critical structures can be dynamically adjusted to a higher opacity, e.g., 80%, hence showing the internal critical structures in a highly opaque way. This dynamic adjustment can also be applied with energy instruments, whereby the transparency value on the pixels overlapping with the energy instruments can be dynamically adjusted and made highly transparent when an energy instrument is present in the scene.

[0072] In further embodiments, the AR overlay 502 may only include an outline 503 of the ultrasound sensing region without blocking the anatomy in surgeon’s view. This reduces the cognitive load on the surgeon by providing them with registration between organ surface and the precise location of where the ultrasound image readings inside the organ.

[0073] In additional embodiments, overlays according to the present disclosure could also be viewed by OR staff, remote viewing, or recording. Furthermore, this same dithering approach could be applied to stereoscopic displays having two 2D screens that are used to create a 3D image by sending each image to the left and right eyes. The display screen 32 may be a stereoscopic display, in which case the overlay is processed for each left and right channel separately, i.e., the overlay is dithered in the left and right channel images separately, then combining the images together to render on stereoscopic 3D screen. The dithering approach could also be used in an AR headset. The dithering could also be applied to other overlays such as error messages, warnings, and other information to guide the surgeon and OR staff during the procedure via dithering.

[0074] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended thereto.

[0075] The following examples are illustrative of the techniques described herein.

[0076] Example 1. A method for generating a transparent augmented reality (AR) overlay in a surgical robotic system, the method comprising: receiving an image for use as the AR overlay; receiving a video feed from a laparoscopic camera; selecting a location for the AR overlay on a display screen including pixels showing the video feed; generating the AR overlay using a dithering process, wherein the dithering process replaces a portion of the pixels showing the video feed with the image to create a semi-transparent effect; displaying the dithered AR overlay on the display screen along with a laparoscopic video feed; and adjusting the transparency of the AR overlay dynamically based on user input and surgical context.

[0077] Example 2. The method of Example 1, wherein the image for the AR overlay is obtained from a pre-operative imaging modality selected from the group consisting of computed tomography (CT) and magnetic resonance imaging (MRI).

[0078] Example 3. The method of Example 1, wherein the image for the AR overlay is obtained from an intra-operative imaging modality selected from the group consisting of ultrasound, gamma probe, and Raman spectroscopy.

[0079] Example 4. The method of Example 1, further comprising: receiving input through a graphical user interface (GUI) to control the transparency of the AR overlay, wherein the GUI includes a slider to control one of transparency or opacity of the AR overlay.

[0080] Example 5. The method of Example 1, wherein the dithering process further includes rendering a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying.

[0081] Example 6. The method of Example 1, further comprising: adjusting transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay.

[0082] Example 7. The method of Example 6, wherein the transparency of the AR overlay is adjusted based on its position on the display screen, with a higher transparency in the center of the display screen.

[0083] Example 8. The method of Example 6, wherein adjusting the transparency includes increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when the overlay is positioned over non-critical areas.

[0084] Example 9. The method of Example 1, further comprising: dividing the display screen into protected and unprotected zones, wherein transparency of the AR overlay is increased when positioned in the protected zone.

[0085] Example 10. A surgical robotic system comprising: a display screen configured to output a video feed of a surgical site from a laparoscopic camera; an imaging device configured to capture images of the surgical site; and a processing device configured to: receive an image for generating a transparent augmented reality (AR) overlay; receive a video feed from a laparoscopic camera; select a location for the AR overlay on a display screen including pixels showing the video feed; generate the AR overlay using a dithering process, wherein the dithering process replaces a portion of the pixels showing the video feed with the image to create a semi-transparent effect; display the dithered AR overlay on the display screen along with a laparoscopic video feed; and adjust the transparency of the AR overlay dynamically based on user input and surgical context.

[0086] Example 11. The system of Example 10, wherein the imaging device is a preoperative imaging device selected from the group consisting of computed tomography (CT) scans and magnetic resonance imaging (MRI) scans.

[0087] Example 12. The system of Example 10, wherein the imaging device is an intraoperative imaging device selected from the group consisting of ultrasound, gamma probe, and Raman spectroscopy.

[0088] Example 13. The system of Example 10, wherein the display screen is configured to output a graphical user interface (GUI) to control the transparency of the AR overlay, wherein the GUI includes a slider to control one of transparency or opacity of the AR overlay.

[0089] Example 14. The system of Example 10, wherein the processing device is further configured to render a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying.

[0090] Example 15. The system of Example 10, wherein the processing device is further configured to adjust transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay.

[0091] Example 16. The system of Example 15, wherein the transparency of the AR overlay is adjusted based on its position on the display screen, with a higher transparency in the center of the display screen.

[0092] Example 17. The system of Example 15, wherein the processing device is further configured to adjust the transparency by increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when the overlay is positioned over non-critical areas.

[0093] Example 18. The system of Example 10, wherein the processing device is further configured to divide the display screen into protected and unprotected zones, wherein transparency of the AR overlay is increased when positioned in the protected zone.

Claims

WHAT IS CLAIMED IS:

1. A method for generating a transparent augmented reality (AR) overlay in a surgical robotic system, the method comprising: receiving an image for use as the AR overlay; receiving a video feed from a laparoscopic camera; selecting a location for the AR overlay on a display screen including pixels showing the video feed; generating the AR overlay using a dithering process, wherein the dithering process replaces a portion of the pixels showing the video feed with the image to create a semitransparent effect; displaying the dithered AR overlay on the display screen along with a laparoscopic video feed; and adjusting the transparency of the AR overlay dynamically based on user input and surgical context.

2. The method of claim 1, wherein the image for the AR overlay is obtained from a pre-operative imaging modality selected from the group consisting of computed tomography (CT) and magnetic resonance imaging (MRI).

3. The method of claim 1, wherein the image for the AR overlay is obtained from an intra-operative imaging modality selected from the group consisting of ultrasound, gamma probe, and Raman spectroscopy.

4. The method of claim 1, further comprising: receiving input through a graphical user interface (GUI) to control the transparency of the AR overlay, wherein the GUI includes a slider to control one of transparency or opacity of the AR overlay.

5. The method of claim 1, wherein the dithering process further includes rendering a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying.

6. The method of claim 1, further comprising: adjusting transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay.

7. The method of claim 6, wherein the transparency of the AR overlay is adjusted based on its position on the display screen, with a higher transparency in the center of the display screen.

8. The method of claim 6, wherein adjusting the transparency includes increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when the overlay is positioned over non-critical areas.

9. The method of claim 1, further comprising: dividing the display screen into protected and unprotected zones, wherein transparency of the AR overlay is increased when positioned in the protected zone.

10. A surgical robotic system comprising: a display screen configured to output a video feed of a surgical site from a laparoscopic camera; an imaging device configured to capture images of the surgical site; and a processing device configured to: receive an image for generating a transparent augmented reality (AR) overlay; receive a video feed from a laparoscopic camera; select a location for the AR overlay on a display screen including pixels showing the video feed; generate the AR overlay using a dithering process, wherein the dithering process replaces a portion of the pixels showing the video feed with the image to create a semi-transparent effect; display the dithered AR overlay on the display screen along with a laparoscopic video feed; andadjust the transparency of the AR overlay dynamically based on user input and surgical context.

11. The system of claim 10, wherein the imaging device is a pre-operative imaging device selected from the group consisting of computed tomography (CT) scans and magnetic resonance imaging (MRI) scans.

12. The system of claim 10, wherein the imaging device is an intra-operative imaging device selected from the group consisting of ultrasound, gamma probe, and Raman spectroscopy.

13. The system of claim 10, wherein the display screen is configured to output a graphical user interface (GUI) to control the transparency of the AR overlay, wherein the GUI includes a slider to control one of transparency or opacity of the AR overlay.

14. The system of claim 10, wherein the processing device is further configured to render a portion of the pixels without augmented information as pass-through pixels of the video feed using chroma keying.

15. The system of claim 10, wherein the processing device is further configured to adjust transparency of the AR overlay based on at least one of a critical structure or a surgical instrument being overlayed by the AR overlay.

16. The system of claim 15, wherein the transparency of the AR overlay is adjusted based on its position on the display screen, with a higher transparency in the center of the display screen.

17. The system of claim 15, wherein the processing device is further configured to adjust the transparency by increasing the transparency of the AR overlay when critical structures are detected and decreasing the transparency when the overlay is positioned over non- critical areas.

18. The system of claim 10, wherein the processing device is further configured to divide the display screen into protected and unprotected zones, wherein transparency of the AR overlay is increased when positioned in the protected zone.

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