Patent Description:
Once implanted into a patient, prosthetic devices may sometimes become infected. For example, a biofilm, a community of bacteria in a structural matrix, may infect a prosthetic implant by adhering to the surface of the implant. If a prosthetic implant becomes infected, the first treatment step is to decide whether to remove the infected prosthetic implant, though in the case of an early infection, the prosthetic implant does not necessarily have to be removed. Instead, a thorough debridement of the infected implant and surrounding tissue can be performed by, for example, irrigating the area using an irrigation fluid such as bactericidal solutions, nanoparticle solutions, biofilm inhibiting agents, and/or antibiotics, using an ultrasonic debridement tool, and or using irradiation. The irrigation and debridement should penetrate and destroy, for example, biofilms adhered to the surface of the prosthetic implant, thereby disinfecting the implant. Known systems are disclosed in <CIT> and <CIT>. Further prior art is disclosed in <NPL>.

The invention is defined by the independent claim. Methods referred to hereafter do not form part of the claimed invention.

One aspect of the present disclosure relates to a method for debriding an infected implant area using a robotic-assisted surgery system. The method includes determining, by a processing circuit associated with a computer, an area to be debrided, the debridement area including at least a surface of an implant or patient tissue, and generating, by the processing circuit, a plan for debriding the debridement area. The method further includes controlling a debridement tool while the debridement tool is used to carry out the debridement plan, and monitoring, by the processing circuit, the debridement.

An embodiment of the invention relates to a system for debriding an infected implant area. The system includes a robotic system including an articulated arm and a debridement tool coupled to the articulated arm and a processing circuit including a processor and non-transitory machine readable media with instructions stored thereon. The processing circuit is configured to determine an area to be debrided, the debridement area including at least a surface of an implant or patient tissue, and generate a plan for debriding the debridement area. The processing circuit is further configured to control a debridement tool while the debridement tool is used to carry out the debridement plan, and monitor the debridement.

The accompanying drawings, which are incorporated and constitute a part of this specification, illustrate several embodiments that, together with the description, serve to explain the principles and features of the present disclosure.

Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures.

The present disclosure introduces a robotic-assisted approach to treating an implanted prosthetic device, such as a knee joint replacement or a hip joint replacement, by debriding the infected prosthesis and the surrounding tissue, such as by irrigation, ultrasonic debridement, irradiation to kill bacteria, or a combination thereof With effective debridement of an infected prosthesis, early infections can be treated without the need for the prosthesis to be removed. Alternatively, more severe infections can be treated by removing the infected prosthesis, cleaning the infected prosthesis, and irrigating the infected patient tissues. In some embodiments, removal of the prosthesis can be carried out according to systems and methods described in <CIT> and entitled "Systems and Methods for a Robotic-Assisted Revision Procedure.

While implant and tissue debridement can be done manually by a practitioner, manual debridement relies on the practitioner's ability to cover the entire infected area. By contrast, the systems and methods described herein provide several technical advantages over existing debridement processes. For one, a practitioner using the robotic-assisted system described herein to irrigate an infected implant and/or tissue can use the robotic-assisted system to generate a debridement plan for covering all affected surfaces with an irrigation fluid, such as bactericidal solutions, nanoparticle solutions, biofilm inhibiting agents, and/or antibiotics. Further, the robotic-assisted system is able to assist the practitioner in carrying out the plan, or autonomously carry out the plan, as well as monitor the irrigation to confirm that even difficult-to-reach surfaces receive at least a minimum amount of debridement (e.g., which decreases the risk of leaving a portion of biofilm on the infected implant or leaving a portion of infected tissue untreated). Furthermore, the robotic-assisted system may be used to generate and implement a debridement plan using an ultrasonic tool for removing tissue from an implant component using robotic-assistance or autonomously. Finally, debridement can be planned for irriadiation to kill bacteria on the implant. The debridement plans and process described herein may involve irrigation, ultrasonic debridement, irradiation, or any combination thereof.

Though the present disclosure makes reference to the knee and hip joints, and treating infected implants and surrounding tissues for the knee and the hip joints, the systems and methods disclosed herein are equally applicable to infected implants for other bones or joints and their surrounding tissues. For example, the systems and methods disclosed herein may be used with implants for the shoulder, the wrist, the spine, the ankle, etc. The systems and methods disclosed herein are suitable for the debridement of any implantable metallic device which may be used in any arthroplasty procedure and which may use any trauma fixation hardware.

Various features of a robotic-assisted system and methods for debriding an infected implant and/or surrounding tissue according to the present disclosure will now be described in greater detail. <FIG> provides a schematic diagram of an exemplary computer-assisted surgery (CAS) system <NUM>, in which processes and features associated with certain disclosed embodiments may be implemented. CAS system <NUM> may be configured to perform a wide variety of orthopedic surgical procedures (e.g., implantation and revision procedures), as well as other implant-related procedures such as the debridement procedures described herein. CAS system <NUM> includes a navigation system <NUM>, a computing system <NUM>, one or more display devices 103a and 103b, and a robotic system <NUM>.

Robotic system <NUM> can be used in an interactive manner by a practitioner, such as a surgeon, to perform a procedure on a patient. As an example, the surgeon can use the robotic system <NUM> to make incisions such that the practitioner can access an infected implant. As another example, the surgeon can use the robotic system <NUM> to debride the infected implant, as well as the tissue surrounding the infected implant. As shown in <FIG>, robotic system <NUM> includes a base <NUM>, and an articulated arm <NUM>. A surgical tool <NUM> is coupled to one end of the articulated arm <NUM>. The surgical tool <NUM> may be, for example, an end effector having an operating member (e.g., a saw reamer or a burr) or is, in some embodiments, a debridement tool such as an irrigation tool (e.g., a pulsatile lavage hydro jet), an ultrasonic debridement tool, or an irradiation tool. The surgeon can manipulate the surgical tool <NUM> by grasping and manually moving the articulated arm <NUM> and/or the surgical tool <NUM>. Alternatively, the surgeon can manipulate the surgical tool <NUM> by using an input/output device (not shown) to move the articulated arm <NUM> and/or the surgical tool <NUM> (e.g., by using a keyboard, a joystick, etc. to move the articulated arm <NUM> and/or the surgical tool <NUM>).

Some embodiments of the robotic system <NUM> may further include a force system and a controller configured to provide a restraint guide. For example, the robotic system <NUM> may provide a restraint guide to aid a surgeon in preparing a bone to receive an implant or debriding an infected implant. The restraint guide may operate by providing control or guidance to the surgeon during manipulation of the surgical tool <NUM>. When providing a restraint guide, the force system is configured to provide at least some force to the surgical tool <NUM> via the articulated arm <NUM>, and the controller is programmed to generate control signals for controlling the force system. In one embodiment, the force system includes actuators and a back-drivable transmission that provide haptic (or force) feedback to constrain or inhibit the surgeon from manually moving the surgical tool <NUM> beyond predefined haptic boundaries defined by haptic objects as described, for example, in <CIT> and/or <CIT>. The force system and controller may be housed within the robotic system <NUM>. In some embodiments, a handheld robot can be used, such as described in <CIT> and <CIT>.

Navigation system <NUM> is configured to determine a pose (i.e., position and orientation) of one or more objects during a surgical procedure to detect movement of the object(s). For example, the navigation system <NUM> may include a detection device (e.g., an optical tracking device or a mechanical tracking device) that obtains a pose of an object with respect to a coordinate frame of reference of the detection device. As an object moves in the coordinate frame of reference, the detection device tracks the pose of the object to detect (or enable the CAS system <NUM> to determine) movement of the object. Additionally, by using the navigation system <NUM>, the computing system <NUM> can capture data in response to movement of tracked object or objects. Tracked objects may include, for example, tools/instruments (e.g., the surgical tool <NUM>), patient anatomy, implants/prosthetic devices, and components of the CAS system <NUM>.

The navigation system <NUM> may be any navigation system that enables the CAS system <NUM> to continually determine (or track) a pose of the relevant anatomy of the patient or movement of surgical tool <NUM>. For example, the navigation system <NUM> may include a non-mechanical tracking system, a mechanical tracking system, or any combination of non-mechanical and mechanical tracking systems suitable for use in a surgical environment. A mechanical tracking system may include a mechanical arm having passive joints for tracking and characterizing movement of the tracked object relative to a reference point. A non-mechanical tracking system may include an optical (or visual), magnetic, radio, or acoustic tracking system. Such systems typically include a detection device adapted to locate, in predefined coordinate space, specially recognizable trackable elements (or trackers) that are detectable by the detection device and that are either configured to be attached to an object to be tracked or are an inherent part of an object to be tracked. For example, a trackable element may include an array of markers having a unique geometric arrangement and a known geometric relationship to the tracked object when the trackable element is attached to the tracked object. The known geometric relationship may be, for example, a predefined geometric relationship between the trackable element and an endpoint and axis of the tracked object. Thus, the detection device can recognize a particular tracked object, at least in part, from the geometry of the markers (if unique), an orientation of the axis, and a location of the endpoint within a frame of reference deduced from positions of the markers.

The markers may include any known marker, such as, for example, extrinsic markers (or fiducials) and/or intrinsic features of the tracked object. Extrinsic markers are artificial objects that are attached to the patient and/or other objects to be tracked (e.g., markers affixed to skin, markers implanted in bone, stereotactic frames, etc.). Extrinsic markers designed to be visible to and accurately detectable by the detection device. Intrinsic features are salient and accurately locatable portions of the tracked object that are sufficiently defined and identifiable to function as recognizable markers (e.g., landmarks, outlines of anatomical structure, shapes, colors, or any other sufficiently recognizable visual indicator). The markers may be located using any suitable detection method, such as, for example, optical, electromagnetic, radio, or acoustic methods as are well-known. For example, an optical tracking system having a stationary stereo camera pair sensitive to infrared radiation may be used to track markers that emit infrared radiation either actively (such as a light emitting diode ("LED")) or passively (such as a spherical marker with a surface that reflects infrared radiation). As another example, a magnetic tracking system may include a stationary field generator that emits a spatially varying magnetic field sensed by small coils integrated into the tracked object.

Using pose data from the navigation system <NUM>, the CAS system <NUM> (e.g., via the computing system <NUM> or via a computer of the navigation system <NUM>) is also able to register, map, or coordinates in one space to those in another to achieve spatial alignment or correspondence (e.g., using a coordinate transformation process as is well-known). Objects in physical space may be registered to any suitable coordinate system, such as a coordinate system being used by a process running on a surgical controller and/or a computer device of the robotic system <NUM>. For example, utilizing pose data from the navigation system <NUM>, the CAS system <NUM> is able to associate the physical anatomy, such as the patient's tibia, with a representation of the anatomy (e.g., an image displayed on the display device <NUM>). Based on tracked object and registration data, the CAS system <NUM> may determine, for example, a spatial relationship between the image of the anatomy and the relevant anatomy.

The CAS system <NUM> (e.g., via the computing system <NUM> or via a computer of the navigation system <NUM>) may also include a coordinate transform process for mapping (or transforming) coordinates in one space to those in another in order to achieve spatial alignment or correspondence. For example, the CAS system <NUM> may use the coordinate transform process to map positions of tracked objects (e.g., patient anatomy, implants, components of the CAS system <NUM>, etc.) into a coordinate system used by a process running on a surgical controller and/or computer device of the robotic system <NUM>. As is well-known, a coordinate transform process may include any suitable transformation technique, such as, for example, rigid-body transformation, non-rigid transformation, affine transformation, and the like.

Additionally, the CAS system <NUM> (e.g., via the computing system) may include modeling capabilities such that the CAS system <NUM> may create one or more models of physical objects in virtual space. For example, the CAS system <NUM> may create models of patient anatomy, prosthetic implants, components of the CAS system <NUM>, etc. In one embodiment, the CAS system <NUM> may create one or more models based on imaging data (e.g., from an MRI, from a CT scan, from an ultrasound, etc.). In another embodiment, the CAS system <NUM> may create one or more models based on data from a trackable probe. For example, the surgeon may contact and move a trackable probe over the surface of an implant and/or patient anatomy, and navigation system <NUM> may determine a pose and movement of the trackable probe over the contacted surfaces. The computing system <NUM> may then then create a model of the contacted surfaces based on data from the navigation system regarding the trackable probe. In a third embodiment, the CAS system <NUM> may select one or more models from a database of models (e.g., a database stored in a memory of the computing system <NUM>). In a fourth embodiment, the CAS system <NUM> may select one or more models from a database of models and modify the model(s) based on imaging data, based on data from a trackable probe, etc..

Registration (e.g., registering one or more objects in physical space to virtual space) may include any known registration technique, such as, for example, image-to-image registration (e.g., monomodal registration where images of the same type or modality, such as fluoroscopic images or magnetic resonance images, are registered and/or multimodal registration where images of different types or modalities, such as MRI and CT, are registered), image-to-physical space registration (e.g., image-to-patient registration where a digital data set of a patient's anatomy obtained by conventional imaging techniques is registered with the patient's actual anatomy), combined image-to-image and image-to-physical-space registration (e.g., registration of preoperative CT and MRI images to an intraoperative scene), and/or registration using a video camera with tracking capabilities to create an initial model. For example, in some embodiments, the CAS system <NUM> includes video camera and various trackers to track one or more objects in physical space. The computing system <NUM> receives a scan of patient anatomy, obtains a model based on the scan, and registers the one or more objects in physical space to the model. In one embodiment, the computing system <NUM> creates an initial 3D model and automatically registers one or more physical objects to the 3D model (e.g., the computing system <NUM> uses a video camera to register a 3D model corresponding to a CT scan).

In various embodiments, registration with respect to the robotic-assisted debridement procedures described herein includes determining or digitizing an area to be debrided, for example, an area to be irrigated (e.g., an irrigation area or a lavage zone) with an irrigation fluid, such as bactericidal solutions, nanoparticle solutions, biofilm inhibiting agents, and/or antibiotics using the above-described registration and/or tracking methods. In one embodiment, the irrigation area is determined by using a pre-operative scan of the infected implant and surrounding tissue. In another embodiment, the irrigation area is digitized through the use of a trackable probe. The surgeon touches the probe to the patient anatomy and/or to the infected implant to trace the irrigation area (e.g., trace a perimeter of the irrigation area). The navigation system <NUM> tracks the probe (e.g., using markers on the probe or using the geometry of the probe), and the CAS system <NUM> uses the data from the navigation system <NUM> to digitize the irrigation area.

As noted above, the computing system <NUM> may execute one or more processes relating to registration. Accordingly, the computing system <NUM> may be communicably coupled to the navigation system <NUM> and may be configured to receive data from the navigation system <NUM>. Based on the received navigation data, computing system <NUM> may determine the position and orientation associated with one or more registered features of the surgical environment, such as surgical tool <NUM> or portions of the patient's anatomy. Computing system <NUM> may further include modeling software used during various procedures. Furthermore, computing system <NUM> may include surgical planning and surgical assistance software that may be used by a surgeon or surgical support staff during the surgical procedure. For example, during a debridement procedure, computing system <NUM> may display images related to the procedure on one or both of the display devices 103a and 103b.

Computing system <NUM> (and/or one or more constituent components of CAS system <NUM>) may include hardware and software for operation and control of the CAS system <NUM>. Such hardware and/or software is configured to enable the CAS system <NUM> to perform the techniques described herein. As an illustration, <FIG> shows a block diagram of the computing system <NUM> according to an exemplary embodiment. The computing system includes a surgical controller <NUM>, a display device <NUM> (e.g., display devices 103a and 103b), and an input device <NUM>.

The surgical controller <NUM> may be any known computing system but is preferably a programmable, processor-based system. For example, the surgical controller <NUM> may include a microprocessor, a hard drive, random access memory (RAM), read only memory (ROM), input/output (I/O) circuitry, and any other known computer component. The surgical controller <NUM> is preferably adapted for use with various types of storage devices (persistent and removable), such as, for example, a portable drive, magnetic storage, solid state storage (e.g., a flash memory card), optical storage, and/or network/Internet storage. The surgical controller <NUM> may comprise one or more computers, including, for example, a personal computer or a workstation operating under a suitable operating system and may include a graphical user interface ("GUI").

Still referring to <FIG>, in an exemplary embodiment, the surgical controller <NUM> includes a processing circuit <NUM> having a processor <NUM> and memory <NUM>. Processor <NUM> can be implemented as a general purpose processor executing one or more computer programs to perform actions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., a field programmable gate array ("FPGA") or an application specific integrated circuit ("ASIC"), a group of processing components, or other suitable electronic processing components.

Memory <NUM> (e.g., memory, memory unit, storage device, etc.) comprises one or more devices (e.g., RAM, ROM, Flash-memory, hard disk storage, etc.) structured for storing data and/or computer code for completing or facilitating the various processes described in the present application. Memory <NUM> may be or include volatile memory or non-volatile memory. Memory <NUM> may include database components, object code components, script components, or any other type of information structure for supporting the various activities described in the present application. According to an exemplary embodiment, memory <NUM> is communicably connected to processor <NUM> and includes instructions (e.g., computer code) for executing one or more processes described herein. The memory <NUM> may contain a variety of modules, each capable of storing data and/or computer code related to specific types of functions. In one embodiment, memory <NUM> contains several modules related to surgical procedures, such as a planning module 124a, a navigation module 124b, a registration module 124c, and a robotic control module 124d.

Alternatively, or in addition, the computer program instructions can be encoded on an artificially generated propagated signal (e.g., a machine-generated electrical, optical, or electromagnetic signal) that is generated to encode information for transmission to a suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of said devices and/or substrates. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be, or be included in, one or more separate components or media (e.g., multiple CDs, disks, flash drives, or other storage devices). Accordingly, the computer storage medium may be tangible and non-transitory.

A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, or declarative or procedural languages. A computer program can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment.

Generally, a computer, such as computing system <NUM>, will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data (e.g., magnetic, magneto optical disks, or optical disks). Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a tablet, a personal digital assistant ("PDA"), a mobile audio or video player, a game console, a Global Positioning System ("GPS") receiver, or a portable storage device (e.g., a universal serial bus ("USB") flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices), magnetic disks (e.g., internal hard disks or removable disks), magneto optical disks, and CD ROM and DVD-ROM disks. Further, the processor <NUM> and the memory <NUM> can be supplemented by, or incorporated in, special purpose logic circuitry.

Additionally, in various embodiments, the computing system <NUM> is implemented as a computing system that includes a back end component (e.g., as a data server), includes a middleware component (e.g., an application server), or includes a front end component (e.g., a client computer having a GUI or a Web browser through which a user can interact with an embodiment of the subject matter described in this specification), or that includes any combination of one or more such back end, middleware, or front end components. The components of the computing system <NUM> can be interconnected by any form or medium of digital data communication (e.g., a communication network).

Referring to the embodiment of CAS system <NUM> depicted in <FIG>, the surgical controller <NUM> further includes a communication interface <NUM>. The communication interface <NUM> of the computing system <NUM> is coupled to a computing device (not shown) of the robotic system <NUM> via an interface and to the navigation system <NUM> via an interface. The interfaces can include a physical interface and/or a software interface. A physical interface of the communication interface <NUM> can be or include wired or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals, etc.) for conducting data communications with external sources via a direct connection or a network connection (e.g., an Internet connection, a LAN, WAN, or WLAN connection, etc.). A software interface may be resident on the surgical controller <NUM>, the computing device (not shown) of the robotic system <NUM>, and/or the navigation system <NUM>. Furthermore, in some embodiments, the surgical controller <NUM> and the computing device (not shown) of the robotic system <NUM> are the same computing device. The software may also operate on a remote server, be housed in the same building as the CAS system <NUM>, or be housed at an external server site.

Computing system <NUM> also includes display device <NUM>. The display device <NUM> is a visual interface between the computing system <NUM> and the user. The display device <NUM> is connected to the surgical controller <NUM> and may be any device suitable for displaying text, images, graphics, and/or other visual output. For example, the display device <NUM> may include a standard display screen, a touchscreen, a wearable display (e.g., eyewear such as glasses or goggles), a projection display, a head-mounted display, a holographic display, and/or any other visual output device. In certain embodiments, the display may be incorporated into a shield that is part of the surgeon's sterile gown. The display device <NUM> may be disposed on or near the surgical controller <NUM> (e.g., on the cart as shown in <FIG>) or may be remote from the surgical controller <NUM> (e.g., mounted on a stand with the navigation system <NUM>). The display device <NUM> is preferably adjustable so that the user can position/reposition the display device <NUM> as needed during a surgical procedure. For example, the display device <NUM> may be disposed on an adjustable arm (not shown) or to any other location well-suited for ease of viewing by the user. As shown in <FIG> there may be more than one display device <NUM> in the CAS system <NUM> (e.g., display devices 103a and 103b).

The display device <NUM> may be used to display any information useful for a medical procedure, such as, for example, images of anatomy generated from an image data set obtained using conventional imaging techniques, graphical models (e.g., CAD models of implants, instruments, anatomy, etc.), graphical representations of a tracked object (e.g., anatomy, tools, implants, etc.), constraint data (e.g., axes, articular surfaces, etc.), representations of implant components, digital or video images, registration information, calibration information, patient data, user data, measurement data, software menus, selection buttons, status information, and the like.

In addition to the display device <NUM>, the computing system <NUM> may include an acoustic device (not shown) for providing audible feedback to the user. The acoustic device is connected to the surgical controller <NUM> and may be any known device for producing sound. For example, the acoustic device may include speakers and a sound card, a motherboard with integrated audio support, and/or an external sound controller. In operation, the acoustic device may be adapted to convey information to the user. For example, the surgical controller <NUM> may be programmed to signal the acoustic device to produce a sound, such as a voice synthesized verbal indication "DONE," to indicate that a step of a procedure (e.g., a step of irrigating an infected implant and/or infected tissue) is complete.

To provide for other interaction with a user, embodiments of the computing system <NUM> may have an input device <NUM> that enables the user to communicate with the CAS system <NUM>. As shown in <FIG>, the input device <NUM> is connected to the surgical controller <NUM>, and the input device <NUM> may include any device enabling a user to provide input to a computer. For example, the input device <NUM> can be any known input device, such as a keyboard, a mouse, a trackball, a touchscreen, a touchpad, voice recognition hardware or software, dials, switches, buttons, a trackable probe, a foot pedal, a remote control device, a scanner, a camera, a microphone, and/or a joystick. For example, the input device <NUM> may also serve as an output device and provide feedback to the user as any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback) and receive input from the user in any form, including acoustic, speech, or tactile input. In addition, the computing system <NUM> can interact with a user by sending documents to and receiving documents from a device that is used by the user, for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

General surgical planning and navigation to carry out the exemplary methods described above, including control and feedback as described in connection with CAS system <NUM>, may be performed by a computerized surgical system such as that described in <CIT>.

Furthermore, it should be appreciated that CAS system <NUM> described herein, as well as the methods and processes described herein, may be applicable to many different types of implant debridement procedures. Although certain disclosed embodiments may be described herein with reference to methods, systems, and procedures for irrigating a knee implant, the concepts and methods described herein may be applicable to other types debridement procedures, such as hip, shoulder, ankle, and implant debridement procedures. Further, the CAS system <NUM> may include additional elements or fewer elements than those described above to aid in surgery (e.g., a surgical bed, etc.).

<FIG> provides a schematic diagram of the robotic system <NUM> coupled to an irrigation system <NUM>. As shown in <FIG>, surgical tool <NUM> is an irrigation tool <NUM> coupled to the articulated arm <NUM>. In some embodiments, the irrigation tool <NUM> is a pulsed lavage hydro jet configured to create and direct a fluid stream. The pulsed lavage hydro jet may include an elongated nozzle for directing fluids out of the hydro jet (e.g., as shown in <FIG>). Alternatively, the pulsed lavage hydro jet may include a shorter nozzle or a nozzle having a shield. The irrigation tool <NUM> receives irrigation fluid from an irrigation source <NUM> via tubing <NUM>. In some embodiments, the irrigation source <NUM> may be coupled to or incorporated in the robotic system <NUM>. The irrigation fluid may be, for example, a bactericidal solution, nanoparticle solution, biofilm inhibiting agent, antibiotic, and/or any other cleaning or lavage fluid appropriate for infection treatment. Additionally, some embodiments of the irrigation system <NUM> may include a suction tool (not shown) coupled to the irrigation tool <NUM> or separate from the irrigation tool <NUM> for removing fluids that are dispensed from the irrigation tool <NUM>.

In other embodiments, additionally or alternatively, the irrigation tool <NUM> may be an ultrasonic tool, such as ultrasonic tool <NUM> shown in <FIG>. For example, the ultrasonic tool <NUM> may include a probe that uses low frequency, high intensity ultrasound to cause the tip <NUM> of the probe to vibrate. In some embodiments, the ultrasonic frequency provided by the ultrasonic tool <NUM> is between <NUM> and <NUM>. The ultrasonic tool <NUM> may use longitudinal vibration and/or torsional vibration to emulsify tissue with improved precision. The tip <NUM> of the probe may be any variation of soft tissue, implant, or bone scouring tips available or able to be modified for debridement. The ultrasonic tool <NUM> may include an angled body <NUM>, such as the embodiment shown in <FIG>, or may have a straight body. The ultrasonic tool <NUM> may be part of an ultrasonic system which provides ultrasonic power, suction, and irrigation.

When the vibrating tip <NUM> contacts the infected site, the vibration causes micro-sized gas bubbles in the fluids at the infected site, which implode and destroy nearby tissue and bacteria without damaging the bone or any bone cement attaching the implant to the bone. Once the ultrasonic tool <NUM> has fragmented and emulsified infected tissue and bacteria, the tool <NUM> may use aspiration to remove the tissue from the area. In this way, the ultrasonic tool <NUM> is capable of debriding the infected area in a manner that removes bacteria and infected tissue without the use of irrigation fluid or in addition to the use of irrigation fluid, such as bactericidal solutions, nanoparticle solutions, biofilm inhibiting agents, and/or antibiotics. Using ultrasonic tools for debridement can damage (e.g., scratch) an implant component if the ultrasonic tip comes into contact with the component, however, controlling the ultrasonic tool <NUM> with a robotic-assisted system guides the ultrasonic tool <NUM> and prevents contact with the component, thereby improving effectiveness and efficiency of debridement, while minimizing the risk of damage to the implant component. It is to be understood that references elsewhere herein to the irrigation tool <NUM> can also apply to the ultrasonic tool <NUM>, which can be used interchangeably with or in addition to the irrigation tool <NUM>, and in a similar way.

Similar to the surgical tool <NUM>, a surgeon can manipulate the irrigation tool <NUM> by grasping and moving the articulated arm <NUM> and/or the irrigation tool <NUM>. Alternatively, the surgeon can manipulate the irrigation tool <NUM> by an input/output device (not shown) to move the articulated arm <NUM> and/or the irrigation tool <NUM>. It should be understood, however, that the irrigation tool <NUM> an example irrigation tool to be used as part of an irrigation system and that other embodiments of irrigation tools or irrigation systems may be used with the systems and methods described herein.

In some embodiments, the irrigation tool <NUM> is not coupled to the articulated arm <NUM> and is instead manually supported and moved by the surgeon. The navigation system <NUM> is used to track movement of the irrigation tool <NUM> while it is being manually manipulated. The navigation system <NUM> for a manually manipulated irrigation tool <NUM> may be any system as described above, including for example, an optical tracking system or a passive jointed mechanical arm.

As described in further detail below, a surgeon can use the irrigation system <NUM> with the CAS system <NUM> to debride an infected implant, as well as the surrounding tissues, to treat the infected implant. Alternatively, the surgeon can use the irrigation system <NUM> with the CAS system <NUM> to irrigate infected tissues after an infected implant has been removed. An implant positioned in the knee is used herein to describe the process of using the irrigation system <NUM> and the CAS system <NUM> to treat an infected implant and/or infected tissue, though it should be understood that the irrigation system <NUM> and the CAS system <NUM> may be used to treat implants in other bones or joints, including but not limited to shoulder, wrist, spine, and ankle implants. Accordingly, <FIG> illustrate views of a femur <NUM> and a tibia <NUM> with a femoral implant <NUM> and a tibial implant <NUM>, respectively, according to an example embodiment. As shown, the femoral implant <NUM> includes projections, such as a peg <NUM> extending into the femur <NUM>, and the tibial implant <NUM> includes, for example, a keel <NUM>. In <FIG>, the dashed lines of the femoral implant <NUM> and the tibial implant <NUM> denote interior surfaces of the implants <NUM> and <NUM> (e.g., surfaces that are cemented to the femur <NUM> and the tibia <NUM>, respectively). The solid lines of the implants <NUM> and <NUM> denote articulating surfaces of the implants <NUM> and <NUM> (e.g., exposed surfaces that articulate together to form the joint replacement for the femur <NUM> and the tibia <NUM>). Thus, as shown in <FIG>, the femoral implant <NUM> includes a femoral articulating surface <NUM> and the tibial implant <NUM> includes a tibial articulating surface <NUM>.

At times, the femoral implant <NUM> and/or the tibial implant <NUM> will become infected once implanted in the femur <NUM> and tibia <NUM> of an implant. For example, a biofilm may adhere to the femoral articulating surface <NUM> of the femoral implant <NUM> and/or the tibial articulating surface <NUM> of the tibial implant <NUM>. If the femoral implant <NUM> and/or the tibial implant <NUM> become infected, a surgeon must decide whether to remove the infected implants <NUM> and/or <NUM>. In the case of an early infection, however, the surgeon can treat the infection without removing the implants <NUM> and/or <NUM> by thoroughly irrigating the implants <NUM> and <NUM> and debriding the surrounding tissues with an irrigation fluid. Alternatively, if the infection is more serious, the surgeon can remove the infected implants <NUM> and/or <NUM>, clean the infected implants <NUM> and/or <NUM>, and use the irrigation system <NUM> with the CAS system <NUM> to debride the infected patient tissues. The surgeon can then re-insert the cleaned implants <NUM> and/or <NUM>, or new implants, into the patient.

In various embodiments, the implants <NUM> and <NUM> and/or the infected patient tissues may be debrided with an irrigation fluid, such as bactericidal solutions, nanoparticle solutions, biofilm inhibiting agents, antibiotics, and/or any other cleaning or lavage fluid appropriate for infection treatment. The debridement should be able to, for example, penetrate and destroy a biofilm that has formed on the femoral implant <NUM> and/or the tibial implant <NUM>.

As discussed above, while implant debridement can be done without computer guidance, such debridement relies on the surgeon's ability to cover the entire infected area. Accordingly, the surgeon may instead use the CAS system <NUM> described herein to generate a debridement plan that will cover all of the affected areas that need to be irrigated or otherwise debrided. Beneficially, generating a plan with the CAS system <NUM> ensures that the entirety of the affected areas are debrided. Further, the CAS system <NUM> is able to monitor the debridement of the affected areas, based on movement of the articulated arm <NUM> and/or using information from tracking system <NUM>, for example for a manually manipulated tool, to confirm that the affected areas are completely debrided.

<FIG> illustrates a method <NUM> of preparing a debridement plan and debriding an infected prosthetic device, such as femoral implant <NUM> and tibial implant <NUM>, and/or infected patient tissues according to an example embodiment. To begin with, the area to be debrided is determined, in this embodiment, this comprises determining the irrigation area (<NUM>). In some embodiments, the surgeon may identify the infected areas visually. Alternatively, in other embodiments, the surgeon may identify the infected areas with the aid of infection detection systems and methods. For example, the patient may consume or be injected with an imaging agent, such as a fluorescent imaging agent composed of antibodies that bind to proteins in the blood. The antibodies may accumulate in the infection site because of increased blood flow due to inflammation caused by the infection or because the types of proteins the antibodies bind to have accumulated at the source of the infection (e.g., the proteins are on white blood cells accumulating at the infection site). Alternatively, the imaging agent may be composed of antibodies that bind to bacteria common in biofilms and accumulate at the infection site because of the presence of the biofilm bacteria at the site. In certain arrangements, the fluorescent imaging agent may include different antibodies that bind to different proteins (e.g., with some antibodies binding to blood cells, some binding to biofilm bacteria, etc.). Next, the imaging agent is illuminated using a fluorescent imaging system to label the infected areas, allowing the physician to visualize the infected areas and use the robot to debride the infected areas. Alternatively, biofilms may be stained using solutions or dyes (for example, methylene blue, congo red, etc.) which can also allow the physician to visualize the area.

In certain embodiments, the irrigation area is then digitizing. With reference to <FIG>, if the infection is not severe, the irrigation area may include the femoral articulating surface <NUM>, the tibial articulating surface <NUM>, the cement areas for the implants <NUM> and <NUM>, and the tissue surrounding the femoral implant <NUM> and the tibial implant <NUM>, such as the areas of the femur <NUM> and tibia <NUM> and the connective tissue adjacent to the implants <NUM> and <NUM>. If the infection is more severe, the surgeon may first remove the infected implants <NUM> and/or <NUM> before carrying out the method <NUM>, and the irrigation area may include the tissues at and surrounding the site of the removed implants <NUM> and/or <NUM>. In one embodiment, the irrigation area is digitized using a tracked probe. For example, the surgeon touches the tracked probe to the perimeter of the area to be irrigated (e.g., the perimeter of the femoral articulating surface <NUM> and the tibial articulating surface <NUM> or the infected tissues at or surrounding the implant sites for the femoral implant <NUM> and/or the tibial implant <NUM>). In another embodiment, the irrigation area is determined using a pre-operative scan. For example, the irrigation area is imaged using any of a variety of imaging techniques (e.g., CT, MRI, ultrasound, video camera, etc.). Once imaged, a model of the anatomy identifying the irrigation area may be created using the computing system <NUM> according to the modeling systems and methods described above. In further embodiments, the robotic device may be able to automatically detect labeled or stained areas indicating infection and remove the areas without requiring separate imaging or digitizing the determined areas.

After the irrigation area is determined, a plan for irrigating the irrigation area is generated (<NUM>). In various embodiments, robotic planning software executed using the CAS system <NUM> (e.g., executed using the computing system <NUM>) generates the irrigation plan. The robotic planning software bases the irrigation plan on the determined irrigation area and, in some cases, on other constraints of the CAS system <NUM>. For example, the robotic planning software may take into account the properties and constraints of the irrigation tool <NUM> when generating the irrigation plan, such as the range, speed, and pressure of hydro jet spray or the speed of ultrasonic debridement. The irrigation plan is intended to guarantee that all surfaces of the prosthetic implant (e.g., the femoral articulating surface <NUM>, the tibial articulating surface <NUM>, and the bone cement adhering the implants <NUM> and <NUM> to the femur <NUM> and tibia <NUM>, respectively) and/or the tissues at the implant site of a removed prosthetic implant (e.g., the areas of the femur <NUM> and tibia <NUM> and the connective tissues surrounding the implantation sites for the femoral implant <NUM> and the tibial implant <NUM>) in the irrigation area are irrigated. The irrigation plan may be a pre-determined plan that is associated with a particular implant, and may be obtained from a database. The pre-determined plan may be customized by a surgeon based on the actual characteristics of the patient's anatomy and on the infection state of the implant and/or surrounding tissues. In other embodiments, the irrigation plan may be completely customized.

Once created, the surgeon carries out the debridement plan, such as the irrigation plan, using the irrigation system <NUM> coupled to the robotic system <NUM> (<NUM>). In some embodiments, the surgeon carries out the irrigation plan aided by the CAS system <NUM>. In one example, the robotic system <NUM> provides haptic guidance to the surgeon to guide the surgeon in completing the irrigation plan (e.g., by providing resistance or a vibration when the surgeon is straying from the irrigation plan). In another example, the CAS system <NUM> aids with carrying out the irrigation plan by tracking and monitoring movement of the irrigation tool <NUM> where the tool <NUM> is not coupled to an articulated arm. In other embodiments, however, the robotic system <NUM> carries out the irrigation plan autonomously. Additionally, the surgeon may be able to select between options of carrying out the irrigation plan with aid from the CAS system <NUM> or having the robotic system <NUM> carry out the irrigation plan autonomously.

Additionally, in various embodiments, the robotic system <NUM> may adjust parameters of the irrigation tool <NUM> or ultrasonic tool <NUM> to ensure complete debridement of the irrigation area. For example, the robotic system <NUM> may adjust the speed and the pressure of the spray from the irrigation tool <NUM> and/or the parameters of the ultrasonic debridement tool <NUM> to ensure complete cleaning of all surfaces. As another example, the robotic system <NUM> may adjust the speed and the pressure of the spray from the irrigation tool <NUM> and/or the parameters of the ultrasonic debridement tool <NUM> depending on the type of surface that is being cleaned (e.g., provide less pressure when patient tissues are being cleaned as opposed to implant surfaces). Furthermore, in some embodiments, the robotic system <NUM> and/or the surgeon may use an ultraviolet ("UV") light component to target bacterial biofilms on the infected implants and thereby disinfect the implants. The UV light component may be included as part of the irrigation tool <NUM>, may be included as a separate instrument coupled to the robotic system <NUM>, or may be included on a separate robotic or surgical system.

During the debridement of the infected implant according to the debridement plan, the CAS system <NUM> monitors the progress of the debridement to ensure that all surfaces receive at least minimum debridement. For example, the navigation system <NUM> may monitor the movement of the irrigation tool <NUM> with respect to registered patient anatomy and registered implants such that the CAS system <NUM> may determine which areas of the irrigation area have received debridement (e.g., based on the size, pressure, etc. of the spray from the irrigation tool <NUM> and/or ultrasonic debridement tool <NUM>).

In embodiments where the CAS system <NUM> aids the surgeon in carrying out the debridement plan, the CAS system <NUM> may provide feedback to the surgeon based on the monitoring. For example, the robotic system <NUM> may provide haptic guidance to the surgeon to guide the surgeon toward sections of the irrigation area that need additional debridement. In another example, the CAS system <NUM> may display sections of the irrigation area that need additional debridement on the displays 103a and/or 103b or on a separate display (e.g., on the shield that is part of the surgeon's sterile gown). The CAS system <NUM> may show sections that need additional debridement in one color and transition the sections to a second color once they have received at least minimum debridement. In a third example, the CAS system <NUM> may provide oral guidance to the surgeon to guide the surgeon towards sections that need additional debridement. Conversely, in embodiments where the robotic system <NUM> carries out the plan autonomously, the CAS system <NUM> may follow the debridement plan based on the monitoring until all of the irrigation area has received at least minimum debridement. Additionally, in various embodiments, the computing system <NUM> may update the debridement plan if it determines that some sections of the irrigation area are not receiving sufficient debridement under the original irrigation plan.

In cases where the infection was determined to be more severe and the implant(s) (e.g., the femoral implant <NUM> and/or the tibial implant <NUM> were removed), the surgeon may use the CAS system <NUM> to re-implant new or the removed implant(s) in the patient. For example, the surgeon may replace the irrigation tool <NUM> with a tool adapted for re-implantation, formulate a re-implantation surgical plan with the CAS system <NUM>, and follow the surgical plan to re-implant the removed or new implant(s).

The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. As described herein, embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, other magnetic storage devices, solid state storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Claim 1:
A system (<NUM>) for irrigating an infected implant area, the system comprising:
an irrigation tool (<NUM>);
a navigation system (<NUM>) for tracking movement of the irrigation tool (<NUM>);
a robotic system comprising an articulated arm (<NUM>), wherein the irrigation tool (<NUM>) is coupled to the articulated arm (<NUM>); and
a processing circuit (<NUM>) comprising a processor (<NUM>) and non-transitory machine readable media with instructions stored thereon, the processing circuit (<NUM>) configured to;
determine an area to be irrigated, the irrigation area including at least a surface of an implant or patient tissue;
generate a plan for irrigating the irrigation area; and
monitor irrigation of the irrigation area, using data associated with the movement of the irrigation tool (<NUM>) from the navigation system (<NUM>), to ensure that an entirety of the irrigation area receives at least minimum irrigation; and at
adjust the speed and pressure of the spray of irrigation fluid from the irrigation tool (<NUM>) to reduce the speed and pressure of the spray when patient tissues are being cleaned as opposed to implant surfaces.