Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/20—Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/39—Markers, e.g. radio-opaque or breast lesions markers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C1/00—Dental machines for boring or cutting ; General features of dental machines or apparatus, e.g. hand-piece design
  • A61C1/08—Machine parts specially adapted for dentistry
  • A61C1/082—Positioning or guiding, e.g. of drills
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
  • A61B2034/107—Visualisation of planned trajectories or target regions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/20—Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
  • A61B2034/2046—Tracking techniques
  • A61B2034/2055—Optical tracking systems
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/20—Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
  • A61B2034/2068—Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis using pointers, e.g. pointers having reference marks for determining coordinates of body points
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/39—Markers, e.g. radio-opaque or breast lesions markers
  • A61B2090/3983—Reference marker arrangements for use with image guided surgery

Definitions

• the invention relates to location monitoring hardware and software systems. More specifically, the field of the invention is that of surgical equipment and software for monitoring surgical conditions.
• a carrier assembly bears at least one fiducial marker onto an attachment element in a precisely repeatable position with respect to a patient's jaw bone, employing the carrier assembly for providing registration between the fiducial marker and the patient's jaw bone and implanting the tooth implant by employing a tracking system which uses the registration to guide a drilling assembly.
• the present invention is a surgical hardware and software monitoring system and method which allows for surgical planning while the patient is available for surgery, for example while the patient is being prepared for surgery so that the system may model the surgical site.
• the model may be used to track contemplated surgical procedures and warn the physician regarding possible boundary violations that would indicate an inappropriate location in a surgical procedure.
• the hardware may track the movement of instruments during the procedure and in reference to the model to enhance observation of the procedure. In this way, physicians are provided an additional tool to improve surgical planning and performance.
• the system uses a particularly configured fiducial reference, to orient the monitoring system with regard to the critical area.
• the fiducial reference is attached to a location near the intended surgical area.
• a splint may be used to securely locate the fiducial reference near the surgical area.
• the fiducial reference may then be used as a point of reference, or a fiducial, for the further image processing of the surgical site.
• the fiducial reference may be identified relative to other portions of the surgical area by having a recognizable fiducial marker apparent in the scan.
• the system of embodiments of the invention involves automatically computing the three-dimensional location of the patient by means of a tracking device that may be a tracking marker.
• the tracking marker may be attached in fixed spatial relation either directly to the fiducial reference, or attached to the fiducial reference via a tracking pole that itself may have a distinct three-dimensional shape.
• a tracking pole is mechanically connected to the base of the fiducial reference that is in turn fixed in the patient's mouth.
• Each tracking pole device has a particular observation pattern, located either on itself or on a suitable tracking marker, and a particular geometrical connection to the base, which the computer software recognizes as corresponding to a particular geometry for subsequent location calculations.
• tracking pole devices may all share the same connection base and thus may be used with any keyucial reference.
• the particular tracking information calculations are dictated by the particular pole tng pole used, and actual patient location is calculated accordingly.
• pole trackine devices may be interchanged and calculation of the location remains the same. This provides, in the case of dental surgery, automatic recognition of the patient head location in space.
• a sensor device, or a tracker may be in a known position relative to the fiducial key and its tracking pole, so that the current data image may be mapped to the scan image items.
• the fiducial reference and each tracking pole or associated tracking marker may have a pattern made of radio opaque material so that when imaging information is scanned by the software, the particular items are recognized.
• each instrument used in the procedure has a unique pattern on its associated tracking marker so that the tracker information identifies the instrument.
• the software creates a model of the surgical site, in one embodiment a coordinate system, according to the location and orientation of the patterns on the fiducial reference and/or tracking pole(s) or their attached tracking markers.
• analysis software interpreting image information from the tracker may recognize the pattern and may select the site of the base of the fiducial to be at the location where the fiducial reference is attached to a splint. If the fiducial key does not have an associated pattern, a fiducial site is designated. In the dental example this can be at a particular spatial relation to the tooth, and a splint location can be automatically designed for placement of the fiducial reference.
• a surgical monitoring system comprising a fiducial reference configured for removably attaching to a location proximate a surgical site, for having a three-dimensional location and orientation determinable based on scan data of the surgical site, and for having the three-dimensional location and orientation determinable based on image information about the surgical site; a tracker arranged for obtaining the image information; and a controller configured for spatially relating the image information to the scan data and for determining the three-dimensionallocation and orientation of the fiducial reference.
• the fiducial reference may be rigidly and removably attachable to a part of the surgical site. In such an embodiment the fiducial reference may be repeatably attachable in the same three- dimensional orientation to the same location on the particular part of the surgical site.
• the fiducial reference is at least one of marked and shaped for having at least one of its location and its orientation determined from the scan data and to allow it to be uniquely identified from the scan data.
• the surgical monitoring system further comprises a first tracking marker in fixed three-dimensional spatial relationship with the fiducial reference, wherein the first tracking marker is configured for having at least one of its location and its orientation determined by the controller based on the image information and the scan data.
• the first tracking marker may be configured to be removably and rigidly connected to the fiducial reference by a first tracking pole.
• the first tracking pole can have a three- dimensional structure uniquely identifiable by the controller from the image information. The three-dimensional structure of the first tracking pole allows its three-dimensional orientation of the first tracking pole to be determined by the controller from the image information.
• the first tracking pole and fiducial reference may be configured to allow the first tracking pole to connect to a single unique location on the fiducial reference in a first single unique three-dimensional orientation.
• the fiducial reference may be configured for the attachment in a single second unique three-dimensional orientation of at least a second tracking pole attached to a second tracking marker.
• the first tracking marker may have a three-dimensional shape that is uniquely identifiable by the controller from the image information.
• the first tracking marker can have a three-dimensional shape that allows its three-dimensional orientation to be determined by the controller from the image information.
• the first tracking marker may have a marking that is uniquely identifiable by the controller and the marking may be configured for allowing at least one of its location and its orientation to be determined by the controller based on the image information and the scan data.
• the fiducial reference may be a multi-element fiducial pattern comprising a plurality of pattern segments and every segment is individually configured for having a segmental three-dimensional location and orientation determinable based on scan data of the surgical site, and for having the segmental three-dimensional location and orientation determinable based on image information about the surgical site.
• the plurality of pattern segments can have unique differentiable shapes that allow the controller to identify them uniquely from at least one of the scan data and the image information.
• Tracking markers canmay attached to at least a selection of the pattern segments, the tracking markers having at least one of identifying marks and orientation marks that allow their three-dimensional orientations to be determined by the controller from the image information.
• the controller may be configured for determining the locations and orientations of at least a selection of the pattern segments based on the image information and the scan data.
• the controller may be configured for calculating of the locations of anatomical features in the proximity of the multi-element fiducial pattern.
• the surgical monitoring system may comprise further tracking markers attached to implements proximate the surgery site and the controller may be configured for determining locations and orientations of the implements based on the image information and information about the further tracking markers.
• a method for relating in real time the three-dimensional location and orientation of a surgical site on a patient to the location and orientation of the surgical site in a scan of the surgical site comprising removably attaching a fiducial reference to a fiducial location on the patient proximate the surgical site; performing the scan with the fiducial reference attached to the fiducial location to obtain scan data; determining the three-dimensional location and orientation of the fiducial reference from the scan data; obtaining real time image information of the surgical site; determining in real time the three-dimensional location and orientation of the fiducial reference from the image information; deriving a spatial transformation matrix for expressing in real time the three-dimensional location and orientation of the fiducial reference as determined from the image information in terms of the three-dimensional location and orientation of the fiducial reference as determined from the scan data.
• the obtaining of real time image information of the surgical site may comprise rigidly and removably attaching to the fiducial reference a first tracking marker in a fixed three-dimensional spatial relationship with the fiducial reference.
• the first tracking marker may be configured for having its location and its orientation determined based on the image information.
• the attaching of the first tracking marker to the fiducial reference may comprise rigidly and removably attaching the first tracking marker to the fiducial reference by means of a tracking pole.
• the obtaining of the real time image information of the surgical site may comprise rigidly and removably attaching to the fiducial reference a tracking pole in a fixed three-dimensional spatial relationship with the fiducial reference, and the tracking pole may have a distinctly identifiable three-dimensional shape that allows its location and orientation to be uniquely determined from the image information.
• a method for tracking in real time changes in a surgical site comprising removably attaching a multielement fiducial reference to a fiducial location on the patient proximate the surgical site, the multi-element fiducial reference comprising a plurality of pattern segments individually locatable based on scan data; performing a scan with the fiducial reference attached to the fiducial location to obtain the scan data; determining the three-dimensional locations and orientations of at least a selection of the pattern segments from the scan data; obtaining real time image information of the surgical site; determining in real time the three-dimensional locations and orientations of the at least a selection of the pattern segments from the image information; and deriving in real time the spatial distortion of the surgical site by comparing in real time the three-dimensional locations and orientations of the at least a selection of the pattern segments as determined from the image information with the three-dimensional locations and orientations of the at least a selection of the pattern segments as determined from the scan data.
• a method for real time monitoring the position of an object in relation to a surgical site of a patient comprising removably attaching a fiducial reference to a fiducial location on the patient proximate the surgical site; performing a scan with the fiducial reference attached to the fiducial location to obtain scan data; determining the three-dimensional location and orientation of the fiducial reference from the scan data; obtaining real time image information of the surgical site; determining in real time the three-dimensional location and orientation of the fiducial reference from the image information; deriving a spatial transformation matrix for expressing in real time the three-dimensional location and orientation of the fiducial reference as determined from the image information in terms of the three-dimensional location and orientation of the fiducial reference as determined from the scan data; determining in real time the three-dimensional location and orientation of the object from the image information; and relating the three-dimensional location and orientation of the object to the three-dimensional location and orientation of the fiducial reference as determined
• the tracker itself is attached to the fiducial reference so that the location of an object having a marker may be observed from a known position.
• Figure 1 is a schematic diagrammatic view of a network system in which embodiments of the present invention may be utilized.
• FIG. 2 is a block diagram of a computing system (either a server or client, or both, as appropriate), with optional input devices (e.g., keyboard, mouse, touch screen, etc.) and output devices, hardware, network connections, one or more processors, and memory/storage for data and modules, etc. which may be utilized as controller and display in conjunction with embodiments of the present invention.
• input devices e.g., keyboard, mouse, touch screen, etc.
• output devices e.g., hardware, network connections, one or more processors, and memory/storage for data and modules, etc. which may be utilized as controller and display in conjunction with embodiments of the present invention.
• Figures 3A-J are drawings of hardware components of the surgical monitoring system according to embodiments of the invention.
• Figures 4A-C is a flow chart diagram illustrating one embodiment of the registering method of the present invention.
• Figure 5 is a drawing of a dental fiducial key with a tracking pole and a dental drill according to one embodiment of the present invention.
• Figure 6 is a drawing of an endoscopic surgical site showing the fiducial key, endoscope, and biopsy needle according to another embodiment of the invention.
• Figures 7A and 7B are drawings of a multi-element fiducial pattern comprising a plurality of pattern segments in respectively a default condition and a condition in which the body of a patient has moved to change the mutual spatial relation of the pattern segments.
• Figures 8A-C is a flow chart diagram illustrating one embodiment of the registering method of the present invention as applied to the multi-element fiducial pattern of Figures 7 A and 7B.
• a computer generally includes a processor for executing instructions and memory for storing instructions and data, including interfaces to obtain and process imaging data.
• a general-purpose computer has a series of machine encoded instructions stored in its memory, the computer operating on such encoded instructions may become a specific type of machine, namely a computer particularly configured to perform the operations embodied by the series of instructions.
• Some of the instructions may be adapted to produce signals that control operation of other machines and thus may operate through those control signals to transform materials far removed from the computer itself.
• Data structures greatly facilitate data management by data processing systems, and are not accessible except through sophisticated software systems.
• Data structures are not the information content of a memory, rather they represent specific electronic structural elements that impart or manifest a physical organization on the information stored in memory. More than mere abstraction, the data structures are specific electrical or magnetic structural elements in memory, which simultaneously represent complex data accurately, often data modeling physical characteristics of related items, and provide increased efficiency in computer operation.
• the manipulations performed are often referred to in terms, such as comparing or adding, commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operations described herein that form part of the present invention; the operations are machine operations.
• Useful machines for performing the operations of the present invention include general-purpose digital computers or other similar devices. In all cases the distinction between the method operations in operating a computer and the method of computation itself should be recognized.
• the present invention relates to a method and apparatus for operating a computer in processing electrical or other (e.g., mechanical, chemical) physical signals to generate other desired physical manifestations or signals.
• the computer operates on software modules, which are collections of signals stored on a media that represents a series of machine instructions that enable the computer processor to perform the machine instructions that implement the algorithmic steps.
• Such machine instructions may be the actual computer code the processor interprets to implement the instructions, or alternatively may be a higher level coding of the instructions that is interpreted to obtain the actual computer code.
• the software module may also include a hardware component, wherein some aspects of the algorithm are performed by the circuitry itself rather as a result of an instruction.
• the present invention also relates to an apparatus for performing these operations.
• This apparatus may be specifically constructed for the required purposes or it may comprise a general-purpose computer as selectively activated or reconfigured by a computer program stored in the computer.
• the algorithms presented herein are not inherently related to any particular computer or other apparatus unless explicitly indicated as requiring particular hardware.
• the computer programs may communicate or relate to other programs or equipments through signals configured to particular protocols, which may or may not require specific hardware or programming to interact.
• various general-purpose machines may be used with programs written in accordance with the teachings herein, or it may prove more convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these machines will appear from the description below.
• the present invention may deal with "object-oriented” software, and particularly with an "object-oriented” operating system.
• the "object-oriented” software is organized into “objects”, each comprising a block of computer instructions describing various procedures ("methods") to be performed in response to "messages" sent to the object or "events" which occur with the object.
• Such operations include, for example, the manipulation of variables, the activation of an object by an external event, and the transmission of one or more messages to other objects.
• a physical object has a corresponding software object that may collect and transmit observed data from the physical device to the software system. Such observed data may be accessed from the physical object and/or the software object merely as an item of convenience; therefore where "actual data” is used in the following description, such "actual data” may be from the instrument itself or from the corresponding software object or module.
• Messages are sent and received between objects having certain functions and knowledge to carry out processes. Messages are generated in response to user instructions, for example, by a user activating an icon with a "mouse" pointer generating an event. Also, messages may be generated by an object in response to the receipt of a message. When one of the objects receives a message, the object carries out an operation (a message procedure) corresponding to the message and, if necessary, returns a result of the operation. Each object has a region where internal states (instance variables) of the object itself are stored and where the other objects are not allowed to access.
• One feature of the object-oriented system is inheritance. For example, an object for drawing a "circle" on a display may inherit functions and knowledge from another object for drawing a "shape" on a display.
• a programmer "programs" in an object-oriented programming language by writing individual blocks of code each of which creates an object by defining its methods.
• a collection of such objects adapted to communicate with one another by means of messages comprises an object-oriented program.
• Object-oriented computer programming facilitates the modeling of interactive systems in that each component of the system may be modeled with an object, the behavior of each component being simulated by the methods of its corresponding object, and the interactions between components being simulated by messages transmitted between objects.
• An operator may stimulate a collection of interrelated objects comprising an object-oriented program by sending a message to one of the objects.
• the receipt of the message may cause the object to respond by carrying out predetermined functions, which may include sending additional messages to one or more other objects.
• the other objects may in turn carry out additional functions in response to the messages they receive, including sending still more messages.
• sequences of message and response may continue indefinitely or may come to an end when all messages have been responded to and no new messages are being sent.
• a programmer need only think in terms of how each component of a modeled system responds to a stimulus and not in terms of the sequence of operations to be performed in response to some stimulus. Such sequence of operations naturally flows out of the interactions between the objects in response to the stimulus and need not be preordained by the programmer.
• object-oriented programming makes simulation of systems of interrelated components more intuitive, the operation of an object-oriented program is often difficult to understand because the sequence of operations carried out by an object-oriented program is usually not immediately apparent from a software listing as in the case for sequentially organized programs. Nor is it easy to determine how an object-oriented program works through observation of the readily apparent manifestations of its operation. Most of the operations carried out by a computer in response to a program are "invisible" to an observer since only a relatively few steps in a program typically produce an observable computer output.
• the term “object” relates to a set of computer instructions and associated data, which may be activated directly or indirectly by the user.
• the terms “windowing environment”, “running in windows”, and “object oriented operating system” are used to denote a computer user interface in which information is manipulated and displayed on a video display such as within bounded regions on a raster scanned video display.
• the terms “network”, “local area network”, “LAN”, “wide area network”, or “WAN” mean two or more computers that are connected in such a manner that messages may be transmitted between the computers.
• ⁇ typically one or more computers operate as a "server", a computer with large storage devices such as hard disk drives and communication hardware to operate peripheral devices such as printers or modems.
• Other computers termed “workstations”, provide a user interface so that users of computer networks may access the network resources, such as shared data files, common peripheral devices, and inter-workstation communication.
• Users activate computer programs or network resources to create “processes” which include both the general operation of the computer program along with specific operating characteristics determined by input variables and its environment.
• an agent sometimes called an intelligent agent
• an agent using parameters typically provided by the user, searches locations either on the host machine or at some other point on a network, gathers the information relevant to the purpose of the agent, and presents it to the user on a periodic basis.
• the term "desktop” means a specific user interface which presents a menu or display of objects with associated settings for the user associated with the desktop.
• the desktop accesses a network resource, which typically requires an application program to execute on the remote server, the desktop calls an Application Program Interface, or "API", to allow the user to provide commands to the network resource and observe any output.
• API Application Program Interface
• the term “Browser” refers to a program which is not necessarily apparent to the user, but which is responsible for transmitting messages between the desktop and the network server and for displaying and interacting with the network user. Browsers are designed to utilize a communications protocol for transmission of text and graphic information over a worldwide network of computers, namely the "World Wide Web" or simply the "Web”.
• Browsers compatible with the present invention include the Internet Explorer program sold by Microsoft Corporation (Internet Explorer is a trademark of Microsoft Corporation), the Opera Browser program created by Opera Software ASA, or the Firefox browser program distributed by the Mozilla Foundation (Firefox is a registered trademark of the Mozilla Foundation).
• Internet Explorer is a trademark of Microsoft Corporation
• Opera Browser program created by Opera Software ASA
• Mozilla Foundation the Firefox browser program distributed by the Mozilla Foundation
• Browsers display information, which is formatted in a Standard Generalized
• SGML Markup Language
• HTML Hypertext Markup Language
• XML extensible Markup Language
• DTD Document Type Definitions
• PDA personal digital assistant
• WWAN wireless wide area network
• synchronization means the exchanging of information between a first device, e.g. a handheld device, and a second device, e.g. a desktop computer, either via wires or wirelessly. Synchronization ensures that the data on both devices are identical (at least at the time of synchronization).
• CDMA code-division multiple access
• TDMA time division multiple access
• GSM Global System for Mobile Communications
• 3G Third Generation
• 4G fourth Generation
• PDC personal digital cellular
• CDPD packet-data technology over analog systems
• AMPS Advance Mobile Phone Service
• Mobile Software refers to the software operating system, which allows for application programs to be implemented on a mobile device such as a mobile telephone or PDA.
• Examples of Mobile Software are Java and Java ME (Java and JavaME are trademarks of Sun Microsystems, Inc. of Santa Clara, California), BREW (BREW is a registered trademark of Qualcomm Incorporated of San Diego, California), Windows Mobile (Windows is a registered trademark of Microsoft Corporation of Redmond, Washington), Palm OS (Palm is a registered trademark of Palm, Inc.
• Symbian OS is a registered trademark of Symbian Software Limited Corporation of London, United Kingdom
• ANDROID OS is a registered trademark of Google, Inc. of Mountain View, California
• iPhone OS is a registered trademark of Apple, Inc. of Cupertino, California
• Windows Phone 7 “Mobile Apps” refers to software programs written for execution with Mobile Software.
• scan or derivatives thereof refer to x-ray, magnetic resonance imaging (MRI), computerized tomography (CT), sonography, cone beam computerized tomography (CBCT), or any system that produces a quantitative spatial representation of a patient.
• MRI magnetic resonance imaging
• CT computerized tomography
• CBCT cone beam computerized tomography
• the term “fiducial reference” or simply “fiducial” refers to an object or reference on the image of a scan that is uniquely identifiable as a fixed recognizable point.
• fiducial location refers to a useful location to which a fiducial reference is attached. A “fiducial location” will typically be proximate a surgical site.
• the term “marker” or “tracking marker” refers to an object or reference that may be perceived by a sensor proximate to the location of the surgical or dental procedure, where the sensor may be an optical sensor, a radio frequency identifier (RFID), a sonic motion detector, an ultra-violet or infrared sensor.
• RFID radio frequency identifier
• the term “tracker” refers to a device or system of devices able to determine the location of the markers and their orientation and movement continually in 'real time' during a procedure. As an example of a possible implementation, if the markers are composed of printed targets then the tracker may include a stereo camera pair.
• image information is used in the present specification to describe information obtained by the tracker, whether optical or otherwise, and usable for determining the location of the markers and their orientation and movement continually in 'real time' during a procedure.
• Figure 1 is a high-level block diagram of a computing environment 100 according to one embodiment.
• Figure 1 illustrates server 110 and three clients 112 connected by network 114. Only three clients 112 are shown in Figure 1 in order to simplify and clarify the description.
• Embodiments of the computing environment 100 may have thousands or millions of clients 112 connected to network 114, for example the Internet. Users (not shown) may operate software 116 on one of clients 112 to both send and receive messages network 114 via server 110 and its associated communications equipment and software (not shown).
• FIG. 2 depicts a block diagram of computer system 210 suitable for implementing server 110 or client 112.
• Computer system 210 includes bus 212 which interconnects major subsystems of computer system 210, such as central processor 214, system memory 217 (typically RAM, but which may also include ROM, flash RAM, or the like), input/output controller 218, external audio device, such as speaker system 220 via audio output interface 222, external device, such as display screen 224 via display adapter 226, serial ports 228 and 230, keyboard 232 (interfaced with keyboard controller 233), storage interface 234, disk drive 237 operative to receive floppy disk 238, host bus adapter (HBA) interface card 235A operative to connect with Fibre Channel network 290, host bus adapter (HBA) interface card 235B operative to connect to SCSI bus 239, and optical disk drive 240 operative to receive optical disk 242. Also included are mouse 246 (or other point- and-click device, coupled to bus 212 via serial port 228), modem 247 (coupled
• Bus 212 allows data communication between central processor 214 and system memory 217, which may include read-only memory (ROM) or flash memory (neither shown), and random access memory (RAM) (not shown), as previously noted.
• RAM is generally the main memory into which operating system and application programs are loaded.
• ROM or flash memory may contain, among other software code, Basic Input-Output system (BIOS), which controls basic hardware operation such as interaction with peripheral components.
• BIOS Basic Input-Output system
• Applications resident with computer system 210 are generally stored on and accessed via computer readable media, such as hard disk drives (e.g., fixed disk 244), optical drives (e.g., optical drive 240), floppy disk unit 237, or other storage medium. Additionally, applications may be in the form of electronic signals modulated in accordance with the application and data communication technology when accessed via network modem 247 or interface 248 or other telecommunications equipment (not shown).
• Storage interface 23 as with other storage interfaces of computer system
• Modem 247 may provide direct connection to remote servers via telephone link or the Internet via an Internet service provider (ISP) (not shown).
• ISP Internet service provider
• Network interface 248 may provide direct connection to remote servers via direct network link to the Internet via a POP (point of presence).
• Network interface 248 may provide such connection using wireless techniques, including digital cellular telephone connection, Cellular Digital Packet Data (CDPD) connection, digital satellite data connection or the like.
• CDPD Cellular Digital Packet Data
• Software source and/or object codes to implement the present disclosure may be stored in computer-readable storage media such as one or more of system memory 217, fixed disk 244, optical disk 242, or floppy disk 238.
• the operating system provided on computer system 210 may be a variety or version of either MS-DOS® (MS-DOS is a registered trademark of Microsoft Corporation of Redmond, Washington), WINDOWS® (WINDOWS is a registered trademark of Microsoft Corporation of Redmond, Washington), OS/2® (OS/2 is a registered trademark of International Business Machines Corporation of Armonk, New York), UNIX® (UNIX is a registered trademark of X/Open Company Limited of Reading, United Kingdom), Linux® (Linux is a registered trademark of Linus Torvalds of Portland, Oregon), or other known or developed operating system.
• MS-DOS MS-DOS is a registered trademark of Microsoft Corporation of Redmond, Washington
• WINDOWS® WINDOWS is a registered trademark of Microsoft Corporation of Redmond, Washington
• OS/2® OS/2 is a registered
• a signal may be directly transmitted from a first block to a second block, or a signal may be modified (e.g., amplified, attenuated, delayed, latched, buffered, inverted, filtered, or otherwise modified) between blocks.
• a signal may be directly transmitted from a first block to a second block, or a signal may be modified (e.g., amplified, attenuated, delayed, latched, buffered, inverted, filtered, or otherwise modified) between blocks.
• modified signals e.g., amplified, attenuated, delayed, latched, buffered, inverted, filtered, or otherwise modified
• a signal input at a second block may be conceptualized as a second signal derived from a first signal output from a first block due to physical limitations of the circuitry involved (e.g., there will inevitably be some attenuation and delay). Therefore, as used herein, a second signal derived from a first signal includes the first signal or any modifications to the first signal, whether due to circuit limitations or due to passage through other circuit elements which do not change the informational and/or final functional aspect of the first signal.
• the present invention relates to a surgical hardware and software monitoring system and method which allows for surgical planning while the patient is available for surgery, for example while the patient is being prepared for surgery so that the system may model the surgical site.
• the system uses a particularly configured piece of hardware, represented as fiducial key 10 in Figure 3A, to orient tracking marker 12 of the monitoring system with regard to the critical area of the surgery.
• Fiducial key 10 is attached to a location near the intended surgical area, in the exemplary embodiment of the dental surgical area of Figure 3A, fiducial key 10 is attached to a dental splint 14. Tracking marker 12 may be connected to fiducial key 10 by tracking pole 11.
• a tracking marker may be attached directly to the fiducial reference.
• the dental traking marker 14 may be used to securely locate the fiducial 10 near the surgical area.
• the fiducial key 10 may be used as a point of reference, or a fiducial, for the further image processing of data acquired from tracking marker 12 by the tracker.
• additional tracking markers 12 may be attached to items independent of the fiducial key 10 and any of its associated tracking poles 11 or tracking markers 12. This allows the independent items to be tracked by the tracker.
• At least one of the items or instruments near the surgical site may optionally have a tracker attached to function as tracker for the monitoring system of the invention and to thereby sense the orientation and the position of the tracking marker 12 and of any other additional tracking markers relative to the scan data of the surgical area.
• the tracker attached to an instrument may be a miniature digital camera and it may be attached, for example, to a dentist's drill. Any other markers to be tracked by the tracker attached to the item or instrument must be within the field of view of the tracker.
• fiducial key 10 allows computer software stored in memory and executed in a suitable controller, for example processor 214 and memory 217 of computer 210 of Figure 2, to recognize its relative position within the surgical site from the scan data, so that further observations may be made with reference to both the location and orientation of fiducial key 10.
• the fiducial reference includes a marking that is apparent as a recognizable identifying symbol when scanned.
• the fiducial reference includes a shape that is distinct in the sense that the body apparent on the scan has an asymmetrical form allowing the front, rear, upper, and lower, and left/right defined surfaces that may be unambiguously determined from the analysis of the scan, thereby to allow the determination not only of the location of the fiducial reference, but also of its orientation.
• the computer software may create a coordinate system for organizing objects in the scan, such as teeth, jaw bone, skin and gum tissue, other surgical instruments, etc.
• the coordinate system relates the images on the scan to the space around the fiducial and locates the instruments bearing markers both by orientation and position.
• the model generated by the monitoring system may then be used to check boundary conditions, and in conjunction with the tracker display the arrangement in real time on a suitable display, for example display 224 of Figure 2.
• the computer system has a predetermined knowledge of the physical configuration of fiducial key 10 and examines slices/sections of the scan to locate fiducial key 10.
• Locating of fiducial key 10 may be on the basis of its distinct shape, or on the basis of distinctive identifying and orienting markings upon the fiducial key or on attachments to the fiducial key 10 as tracking marker 12.
• Fiducial key 10 may be rendered distinctly visible in the scans through higher imaging contrast by the employ of radio-opaque materials or high-density materials in the construction of the fiducial key 10.
• the material of the distinctive identifying and orienting markings may be created using suitable high density or radio-opaque inks or materials.
• fiducial key 10 Once fiducial key 10 is identified, the location and orientation of the fiducial key 10 is determined from the scan segments, and a point within fiducial key 10 is assigned as the center of the coordinate system. The point so chosen may be chosen arbitrarily, or the choice may be based on some useful criterion.
• a model is then derived in the form of a transformation matrix to relate the fiducial system, being fiducial key 10 in one particular embodiment, to the coordinate system of the surgical site.
• the resulting virtual construct may be used by surgical procedure planning software for virtual modeling of the contemplated procedure, and may alternatively be used by instrumentation software for the configuration of the instrument, for providing imaging assistance for surgical software, and/or for plotting trajectories for the conduct of the surgical procedure.
• the monitoring hardware includes a tracking attachment to the fiducial reference.
• the tracking attachment to fiducial key 10 is tracking marker 12, which is attached to fiducial key 10 via tracking pole 11.
• Tracking marker 12 may have a particular identifying pattern.
• the trackable attachment, for example tracking marker 12, and even associated tracking pole 11 may have known configurations so that observational data from tracking pole 11 and/or tracking marker 12 may be precisely mapped to the coordinate system, and thus progress of the surgical procedure may be monitored and recorded.
• fiducial key 10 may have hole 15 in a predetermined location specially adapted for engagement with insert 17 of tracking pole 11.
• tracking poles 11 may be attached with a low force push into hole 15 of fiducial key 10, and an audible haptic notification may thus be given upon successful completion of the attachment.
• reorient the tracking pole during a surgical procedure may be in order to change the location of the procedure, for example where a dental surgery deals with teeth on the opposite side of the mouth, where a surgeon switches hands, and/or where a second surgeon performs a portion of the procedure.
• the movement of the tracking pole may trigger a re-registration of the tracking pole with relation to the coordinate system, so that the locations may be accordingly adjusted.
• Such a re-registration may be automatically initiated when, for example in the case of the dental surgery embodiment, tracking pole 11 with its attached tracking marker 12 are removed from hole 15 of fiducial key 10 and another tracking marker with its associated tracking pole is connected to an alternative hole on fiducial key 10.
• boundary conditions may be implemented in the software so that the user is notified when observational data approaches and /or enters the boundary areas.
• a surgical instrument or implement herein termed a "hand piece" (see Figures 5 and 6), may also have a particular configuration that may be located and tracked in the coordinate system and may have suitable tracking markers as described herein.
• a boundary condition may be set up to indicate a potential collision with virtual material, so that when the hand piece is sensed to approach the boundary condition an indication may appear on a screen, or an alarm sound.
• target boundary conditions may be set up to indicate the desired surgical area, so that when the trajectory of the hand piece is trending outside the target area an indication may appear on screen or an alarm sound indicating that the hand piece is deviating from its desired path.
• Fiducial key 10' has connection elements with suitable connecting portions to allow a tracking pole 11' to position a tracking marker 12' relative to the surgical site.
• fiducial key 10' serves as an anchor for pole 11' and tracking marker 12' in much the same way as the earlier embodiment, although it has a distinct shape.
• the software of the monitoring system is pre-programmed with the configuration of each particularly identified fiducial key, tracking pole, and tracking marker, so that the location calculations are only changed according to the changed configuration parameters.
• the materials of the hardware components may vary according to regulatory requirements and practical considerations.
• the key or fiducial component is made of generally radio opaque material such that it does not produce noise for the scan, yet creates recognizable contrast on the scanned image so that any identifying pattern associated with it may be recognized.
• the material should be lightweight and suitable for connection to an apparatus on the patient.
• the materials of the fiducial key must be suitable for connection to a plastic splint and suitable for connection to a tracking pole.
• the materials of the fiducial key may be suitable for attachment to the skin or other particular tissue of a patient.
• the tracking markers are clearly identified by employing, for example without limitation, high contrast pattern engraving.
• the materials of the tracking markers are chosen to be capable of resisting damage in autoclave processes and are compatible with rigid, repeatable, and quick connection to a connector structure.
• the tracking markers and associated tracking poles have the ability to be accommodated at different locations for different surgery locations, and, like the fiducial keys, they should also be relatively lightweight as they will often be resting on or against the patient.
• the tracking poles must similarly be compatible with autoclave processes and have connectors of a form shared among tracking poles.
• the tracker employed in tracking the fiducial keys, tracking poles and tracking markers should be capable of tracking with suitable accuracy objects of a size of the order of 1.5 square centimeters.
• the tracker may be, by way of example without limitation, a stereo camera or stereo camera pair. While the tracker is generally connected by wire to a computing device to read the sensory input, it may optionally have wireless connectivity to transmit the sensory data to a computing device.
• tracking markers attached to such a trackable piece of instrumentation may also be light-weight; capable of operating in a 3 object array with 90 degrees relationship; optionally having a high contrast pattern engraving and a rigid, quick mounting mechanism to a standard hand piece.
• Figure 4A and Figure 4B together present, without limitation, a flowchart of one method for determining the three- dimensional location and orientation of the fiducial reference from scan data.
• Figure 4C presents a a flow chart of a method for confirming the presence of a suitable tracking marker in image information obtained by the tracker and determining the three-dimensional location and orientation of the fiducial reference based on the image information.
• the system obtains a scan data set [404] from, for example, a CT scanner and checks for a default CT scan Hounsfield unit (HU) value [at 406] for the fiducial which may or may not have been provided with the scan based on a knowledge of the fiducial and the particular scanner model, and if such a threshold value is not present, then a generalized predetermined default value is employed [408].
• HU Hounsfield unit
• the CT value threshold is adjusted [at 416], the original value restored [at 418], and the segmenting processing scan segments continues [at 410]. Otherwise, with the existing data a center of mass is calculated [at 420], along with calculating the X, Y, and Z axes [at 422]. If the center of mass is not at the cross point of the XYZ axes [at 424], then the user is notified [at 426] and the process stopped [at 428]. If the center of mass is at the XYZ cross point then the data points are compared withe designed fiducial data [430].
• the user is notified [at 434] and the process ends [at 436]. If not, then the coordinate system is defined at the XYZ cross point [at 438], and the scan profile is updated for the HU units [at 440].
• an image is obtained from the tracker, being a suitable camera or other sensor [442].
• the image information is analyzed to determine whether a tracking marker is present in the image information [444]. If not, then the user is queried [446] as to whether the process should continue or not. If not, then the process is ended [448]. If the process is to continue, then the user can be notified that no tracking marker has been found in the image information [450], and the process returns to obtaining image information [442]. If a tracking marker has been found based on the image information, or one has been attached by the user upon the above notification [450], the offset and relative orientation of the tracking marker to the fiducial reference is obtained from a suitable database [452].
• database is used in this specification to describe any source, amount or arrangement of such information, whether organized into a formal multi-element or multi-dimensional database or not.
• a single data set comprising offset value and relative orientation may suffice in a simple implementation of this embodiment of the invention and may be provided, for example, by the user or may be within a memory unit of the controller or in a separate database or memory.
• the offset and relative orientation of the tracking marker is used to define the origin of a coordinate system at the fiducial reference and to determine the three-dimensional orientation of the fiducial reference based on the image information [454] and the registration process ends [458].
• the process may be looped back from step [454] to obtain new image information from the camera [442].
• a suitable query point may included to allow the user to terminate the process.
• Detailed methods for determining orientations and locations of predetermined shapes or marked tracking markers from image data are known to practitioners of the art and will not be dwelt upon here.
• the coordinate system so derived is then used for tracking the motion of any items bearing tracking markers in the proximity of the surgical site.
• Other registration systems are also contemplated, for example using current other sensory data rather than the predetermined offset, or having a fiducial with a transmission capacity.
• FIG. 5 One example of an embodiment of the invention is shown in Figure 5.
• an additional instrument or implement 506 for example a hand piece which may be a dental drill, may be observed by a camera 508 serving as tracker of the monitoring system.
• Surgery site 600 for example a human stomach or chest, may have fiducial key 602 fixed to a predetermined position to support tracking marker 604.
• Endoscope 606 may have further tracking markers, and biopsy needle 608 may also be present bearing a tracking marker at surgery site 600.
• Sensor 610 may be for example a camera, infrared sensing device, or RADAR.
• the fiducial key may comprise a multi-element fiducial pattern 710.
• the multi-element fiducial pattern 710 may be a dissociable pattern.
• the term "dissociable pattern” is used in this specification to describe a pattern comprising a plurality of pattern segments 720 that topologically fit together to form a contiguous whole pattern, and which may temporarily separated from one another, either in whole or in part.
• the term "breakable pattern” is used as an alternative term to describe such a dissociable pattern.
• the segments of the multielement fiducial pattern 710 do not form a contiguous pattern, but instead their positions and orientations with respect to one another are known when the multi-element fiducial pattern 710 is applied on the body of the patient near a critical area of a surgical site.
• Each pattern segment 720 is individually locatable based on scan data of a surgical site to which multielement fiducial pattern 710 may be attached.
• Pattern segments 720 are uniquely identifiable by a suitable tracker 730, being differentiated from one another in one or more of a variety of ways. Pattern segments 720 may be mutually differentiable shapes that also allow the identification of their orientations. Pattern segments 720 may be uniquely marked in one or more of a variety of ways, including but not limited to barcoding or orientation-defining symbols. The marking may be directly on the pattern segments 720, or may be on tracking markers 740 attached to pattern segments 720. The marking may be accomplished by a variety of methods, including but not limited to engraving and printing. In the embodiment shown in Figures 7 A and 7B, by way of non- limiting example, the letters F, G, J, L, P, Q and R have been used.
• the materials of the multi-element fiducial pattern 710 and pattern segments 720, and of any tracking markers 740 attached to them, may vary according to regulatory requirements and practical considerations.
• the key or fiducial component is made of generally radio opaque material such that it does not produce noise for the scan, yet creates recognizable contrast on the scanned image so that any identifying pattern associated with it may be recognized.
• the multi-element fiducial pattern 710 and pattern segments 720 may have a distinct coloration difference from human skin in order to be more clearly differentiable by tracker 730.
• the material should be lightweight. The materials should also be capable of resisting damage in autoclave processes.
• a suitable tracker of any of the types already described is used to locate and image multi-element fiducial pattern 710 within the surgical area.
• Multi-element fiducial pattern 710 may be rendered distinctly visible in scans of the surgical area through higher imaging contrast by the employ of radio-opaque materials or high-density materials in the construction of theti-element fiducial pattern 710.
• the distinctive identifying and orienting markings on the pattern segments 720 or on the tracking markers 740 may be created using suitable high-density materials or radio-opaque inks, thereby allowing the orientations of pattern segments 720 to be determined based on scan data.
• pattern segments 720 of multi-element fiducial pattern 710 change their relative locations and also, in general, their relative orientations. Information on these changes may be used to gain information on the subcutaneous motion of the body of the patient in the general vicinity of the surgical site by relating the changed positions and orientations of pattern segments 720 to their locations and orientations in a scan done before surgery.
• multi-element fiducial pattern 710 allows computer software to recognize its relative position within the surgical site, so that further observations may be made with reference to both the location and orientation of multi-element fiducial pattern 710.
• the computer software may create a coordinate system for organizing objects in the scan, such as skin, organs, bones, and other tissue, other surgical instruments bearing suitable tracking markers, and segments 720 of multi-element fiducial pattern 710 etc.
• the computer system has a predetermined knowledge of the configuration of multi-element fiducial pattern 710 and examines slices of a scan of the surgical site to locate pattern segments 720 of multi-element fiducial pattern 710 based on one or more of the radio-opacity density of the material of the pattern segments 720, their shapes and their unique tracking markers 740. Once the locations and orientations of the pattern segments 720 have been determined, a point within or near multi-element fiducial pattern 710 is assigned as the center of the coordinate system. The point so chosen may be chosen arbitrarily, or the choice may be based on some useful criterion. A transformation matrix is derived to relate multi-element fiducial pattern 710 to the coordinate system of the surgical site.
• the resulting virtual construct may then be used by surgical procedure planning software for virtual modeling of the contemplated procedure, and may alternatively be used by instrumentation software for the configuration of the instrument, for providing imaging assistance for surgical software, and/or for plotting trajectories for the conduct of the surgical procedure.
• Multi-element fiducial pattern 710 changes its shape as the body moves during surgery.
• the relative locations and relative orientations of pattern segments 720 change in the process.(see Figure 7A relative to Figure 7B.)
• the integrity of individual pattern segments 720 is maintained and they may be tracked by tracker 730, including but not limited to a stereo video camera.
• the changed multi-element fiducial pattern 710' may be compared with initial multi-element fiducial pattern 710' to create a transformation matrix.
• the relocating and reorienting of pattern segments 720 may therefore be mapped on a continuous basis within the coordinate system of the surgical site.
• Figures 7A and 7B a total of seven pattern segments 720 are shown.
• multielement fiducial pattern 710 may comprise larger or smaller numbers of pattern segments 720.
• a selection of pattern segments 720 may be employed and there is no limitation that all pattern segments 720 of multi-element fiducial pattern 710 have to be employed.
• the decision as to how many pattern segments 720 to employ may, by way of example, be based on the resolution required for the surgery to be done or on the processing speed of the controller, which may be, for example, computer 210 of Figure 2.
• Figure 7A employs a dissociable multi-element fiducial pattern.
• the multi-element fiducial pattern may have a dissociated fiducial pattern, such as that of Figure 7B, as default.
• the individual pattern segments 720 then change position as the body of the patient changes shape near the surgical site during the surgery.
• tracking markers 740 may be absent and the tracking system may rely on tracking the pattern segments 720 purely on the basis of their unique shapes, which lend themselves to determining orientation due to a lack of a center of symmetry.
• the pattern segments 720 are not in general limited to being capable of being joined topologically at their perimeters to form a contiguous surface. Nor is there a particular limitation on the general shape of the multielement fiducial pattern.
• FIG. 8A In another aspect of the invention there is presented an automatic registration method for tracking surgical activity using a multi-element fiducial pattern 710, as shown in the flow chart diagram of Fig. 8A, Fig. 8B and Fig. 8C.
• Figure 8A and Figure 8B together present, without limitation, a flowchart of one method for determining the three-dimensional location and orientation of one segment of multi-element fiducial pattern 710 from scan data.
• Figure 8C presents a a flow chart of a method for determining the spatial distortion of the surgical site based on the changed orientations and locations of pattern segments 720 of multi-element fiducial pattern 710, using as input the result of applying the method shown in Figure 8A and figure 8B to every one of the pan segments 720 that is to be employed in the determg the spatial distortion of the surgical site. In principle, not all pattern segments 720 need to be employed.
• the system obtains a scan data set [804] from, for example, a CT scanner and checks for a default CT scan Hounsfield unit (HU) value [806] for the fiducial, which may or may not have been provided with the scan based on a knowledge of the fiducial and the particular scanner model. If such a default value is not present, then a generalized predetermined system default value is employed [808]. Next the data is processed by removing scan slices or segments with Hounsfield data values outside the expected values associated with the fiducial key
• every other pattern segment 720 employed is identified and the three-dimensional location and orientation of all segments 720 employed are determined based on the image information [858].
• the three-dimensional location and orientation of every pattern segment employed based on the image information is compared with the three dimensional location and oreintation of the same pattern segment as based on the scan data [860]. Based on this comparison the spatial distortion of the surgical site is determined [862]. In order to monitor such distortions in real time, the process may be looped back to obtain image information from the camera [848].
• a suitable query point [864] may be included to allow the user to terminate the process [866].
• Detailed methods for determining orientations and locations of predetermined shapes or marked tracking markers from image data are known to practitioners of the art and will not be dwelt upon here.
• the software of the controller for example computer 210 of Figure 2 is capable of recognizing multi-element fiducial pattern 710 and calculating a model of the surgical site based on the identity of multi-element fiducial pattern 710 and its changes in shape based on the observation data received from multi-element fiducial pattern 710. This allows the calculation in real time of the locations and orientations of anatomical features in the proximity of the multi-element fiducial pattern 710.

Applications Claiming Priority (5)

Publications (1)

Family

ID=50877787

Family Applications (1)

Country Status (5)

Families Citing this family (10)

Citations (1)

Family Cites Families (6)

• 2012
  • 2012-10-21 KR KR1020147013824A patent/KR20140088167A/ko not_active Application Discontinuation
  • 2012-10-21 JP JP2014537811A patent/JP2015508293A/ja active Pending
  • 2012-10-21 WO PCT/IL2012/000363 patent/WO2013061318A1/en active Application Filing
  • 2012-10-21 EP EP12798885.5A patent/EP2770935A1/en not_active Withdrawn
  • 2012-10-21 CA CA2852793A patent/CA2852793C/en not_active Expired - Fee Related
• 2016
  • 2016-11-25 JP JP2016228600A patent/JP2017074389A/ja active Pending

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events