Patent Application
20180055579
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.
Visual and other sensory systems are known, with such systems being capable of both observing and monitoring surgical procedures. With such observation and monitoring systems, computer aided surgeries are now possible, and in fact are being routinely performed. In such procedures, the computer software interacts with both clinical images of the patient and observed surgical images from the current surgical procedure to provide guidance to the physician in conducting the surgery. For example, in one known system 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. With this relatively new computer implemented technology, further improvements may further advance the effectiveness of surgical procedures.
The present invention involves embodiments of 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. In one embodiment, 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. In another embodiment, 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. For example, in the example of a dental surgery, 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 embodiments of the invention involve 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. In the dental surgery example, 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. Although individual tracking pole devices have distinct configurations, they may all share the same connection base and thus may be used with any fiducial reference. The particular tracking information calculations are dictated by the particular tracking pole used, and actual patient location is calculated accordingly. Thus, tracking pole 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. Alternatively, 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 bear a pattern, made of radio opaque material in the case of the fiducial. When imaging information or previous scans of the surgical site are interpreted by the software, the particular items are recognized. Typically, 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. By way of example, in the embodiment where the fiducial reference has an associated pre-assigned pattern, 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 may be at a particular spatial relation to the tooth, and a splint location may be automatically designed for placement of the fiducial reference.
In a first aspect of the invention there is provided a surgical monitoring system comprising a vectorized 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-dimensional location and orientation of the fiducial reference. In one embodiment of the invention 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 vectorized 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 vectorized 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 may 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 may 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 surgical monitoring system may comprise further vectorized 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.
In another aspect of the invention there is provided 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, the method comprising removably attaching a vectorized 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 or 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 vectorized 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 be vectorized in having a distinctly identifiable three-dimensional shape that allows its location and orientation to be uniquely determined from the image information.
In yet a further aspect of the invention there is provided a method for real time monitoring the position of an object in relation to a surgical site of a patient, the method comprising removably attaching a vectorized 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 from the image information. The determining in real time of the three-dimensional location and orientation of the object from the image information may comprise rigidly attaching a vectorized tracking marker to the object.
In one alternative embodiment, the tracker itself is attached to the fiducial reference so that the location of an object having a vectorized marker may be observed from a known position.
In a further aspect, the system may be configured as a robotic surgery system. The controller may control a robotic surgery instrument, guiding it to execute the surgical process based on image information from the tracker. The image information of a tracking marker allows determination of the three-dimensional pose of the fiducial marker for which a prior scan has provided scan data for use by the controller. Computer software stored in a memory of the controller is executed in a processor of the controller to guide the instrument. The instrument may be a biopsy needle. The controller may operate on an autonomous basis, with human intervention being optional. The fiducial remains rigidly attached to the surgical site, and the marker remains in its fixed relative position and orientation with respect to fiducial if and when the patient moves. With both markers tracked by the tracker, the controller may autonomously guide the robotic instrument despite the motion of the patient. In cases where the fiducial reference is directly visible to the tracker the fiducial may itself be vectorized with suitable markers bearing patterns that allow the spatial position and orientation of the fiducial to be directly tracked by the tracker without requiring separate tracking markers to be attached to the fiducial tracking poles.
In a further aspect, a method is provided for guiding at a surgical site a robotic surgery instrument, the method comprising providing proximate the surgical site the robotic surgery instrument bearing in fixed three-dimensional spatial relationship with the instrument a first passive vectorized tracking marker, the marker bearing at least one first identifiably unique rotationally asymmetric pattern; disposing a non-stereo optical tracker to obtain image information of the surgical site and the instrument; obtaining image information about the surgical site from the non-stereo optical tracker; obtaining geometric information from a database, the geometric information comprising information about the first tracking marker; identifying the first tracking marker in the image information on the basis of the at least one first unique pattern; determining within the image information the location of at least one first pattern reference point of the first tracking marker based on the geometric information; determining within the image information the rotational orientation of the first tracking marker based on the geometric information; and guiding the robotic surgery instrument based on the location of the at least one first pattern reference point and the rotational orientation of the first tracking marker.
In some implementations of the method, the fiducial reference may directly bear the second tracking marker, so that the step of attaching to the fiducial reference the second tracking marker in fixed three-dimensional spatial relationship with the fiducial reference is obviated.
In a further aspect, a user-calibration-free tracking system is provided for monitoring the position and orientation of non-visible scan-detectable structure of a body of interest, the system comprising: a vectorized fiducial reference adapted to be rigidly attached to the body of interest, the fiducial reference comprising a structural body composed of a structural material compatible with a material of the body of interest and one or more scan-detectable elements composed of a scan-detectable material rigidly embedded in the structural material wherein the one or more scan-detectable elements comprise a rotationally non-symmetric pattern; a passive vectorized tracking marker rigidly attached to the fiducial reference at a predetermined location in a predetermined three-dimensional orientation with respect to the fiducial reference; a non-stereo optical tracker arranged to obtain image information about an area encompassing at least a portion of the tracking marker; a controller in communication with the tracker; a display system in communication with the controller; and previously obtained scan data of the body of interest with the fiducial reference fixed to the body showing the scan-detectable elements relative to the non-visible structure of the body of interest; wherein the controller comprises a processor, a memory and a software program having a series of instructions which when executed by the processor determine the relative position and orientation of the marker and the one or more scan-detectable elements based on the image information and the scan data. The tracking marker may be removably attached to the fiducial reference and may be attached to the fiducial reference via a tracking pole.
The system may further comprise a database, the database containing: geometric information about the tracking marker; and information about the rotationally non-symmetric pattern of the one or more scan-detectable elements.
In a further aspect a fiducial reference is provided for use in tracking a non-visible scan-detectable structure of a body of interest, the fiducial reference comprising: a structural body composed of a structural material compatible with a material of the body of interest; and one or more scan-detectable elements composed of a scan-detectable material rigidly embedded in the structural material; wherein the one or more scan-detectable elements comprise a rotationally non-symmetric pattern. The one or more scan-detectable elements may be embedded in the structural material with 100% precision to an accuracy compatible with one of human and animal surgery. The accuracy may be a distance of 150 microns or less. In other cases the accuracy may be a distance of 80 microns or less. In yet other cases the accuracy may be a distance of 40 microns or less. More particularly, the accuracy may be a distance of 16 microns or less.
The scan-detectable material may have a radiographic density approximating a radiographic density of one of human and animal bone. The scan-detectable material may be one of a metal, a metallic-oxide ceramic, and silicon nitride. More specifically, the scan-detectable material may be one of stainless steel, titanium, aluminum oxide, and zirconium oxide.
The fiducial reference may further comprise a vectorized tracking marker. The tracking marker may further bear an optically detectable rotationally asymmetric pattern. The fiducial reference may further comprise a locating hole for rigidly and removably attaching a vectorized tracking marker. The tracking marker may bear an optically detectable rotationally asymmetric pattern. The tracking marker may be attachable to the fiducial by means of a tracking pole.
In a further aspect, a method is provided for manufacturing a multi-material fiducial reference for tracking a non-visible scan-detectable structure of a body of interest, the method comprising: providing one or more scan-detectable elements; providing a mold shaped to receive the one or more scan-detectable elements and an injection moldable material compatible with the body of interest; rigidly positioning in a predetermined position and orientation within the mold the one or more scan-detectable elements by means of pins to an accuracy of at least 150 microns; and injecting the injection moldable material into the mold while rigidly holding the scan-detectable elements by means of the pins. The method may further comprise removing the pins; and further injecting additional injection moldable material to surround the scan-detectable elements.
The abovementioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The flow charts and screen shots are also representative in nature, and actual embodiments of the invention may include further features or steps not shown in the drawings. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
The detailed descriptions that follow are presented in part in terms of algorithms and symbolic representations of operations on data bits within a computer memory representing alphanumeric characters or other information. The hardware components are shown with particular shapes and relative orientations and sizes using particular scanning techniques, although in the general case one of ordinary skill recognizes that a variety of particular shapes and orientations and scanning methodologies may be used within the teaching of the present invention. A computer generally includes a processor for executing instructions and memory for storing instructions and data, including interfaces to obtain and process imaging data. When 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. These descriptions and representations are the means used by those skilled in the art of data processing arts to most effectively convey the substance of their work to others skilled in the art.
An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulations of physical quantities, observing and measuring scanned data representative of matter around the surgical site. Usually, though not necessarily, these quantities take the form of electrical or magnetic pulses or signals capable of being stored, transferred, transformed, combined, compared, and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, symbols, characters, display data, terms, numbers, or the like as a reference to the physical items or manifestations in which such signals are embodied or expressed to capture the underlying data of an image. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely used here as convenient labels applied to these quantities.
Some algorithms may use data structures for both inputting information and producing the desired result. 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.
Further, 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. In some cases, 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. In particular, 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. Often, but not necessarily, 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 here 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. In this manner, 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. When modeling systems utilizing an object-oriented language, 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.
Although 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.
In the following description, several terms that are used frequently have specialized meanings in the present context. 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. In such computer networks, 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. Similar to a process is an agent (sometimes called an intelligent agent), which is a process that gathers information or performs some other service without user intervention and on some regular schedule. Typically, 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. When 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. 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”. Examples of 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). Although the following description details such operations in terms of a graphic user interface of a Browser, the present invention may be practiced with text based interfaces, or even with voice or visually activated interfaces, that have many of the functions of a graphic based Browser.
Browsers display information, which is formatted in a Standard Generalized Markup Language (“SGML”) or a HyperText Markup Language (“HTML”), both being scripting languages, which embed non-visual codes in a text document through the use of special ASCII text codes. Files in these formats may be easily transmitted across computer networks, including global information networks like the Internet, and allow the Browsers to display text, images, and play audio and video recordings. The Web utilizes these data file formats to conjunction with its communication protocol to transmit such information between servers and workstations. Browsers may also be programmed to display information provided in an eXtensible Markup Language (“XML”) file, with XML files being capable of use with several Document Type Definitions (“DTD”) and thus more general in nature than SGML or HTML. The XML file may be analogized to an object, as the data and the stylesheet formatting are separately contained (formatting may be thought of as methods of displaying information, thus an XML file has data and an associated method).
The terms “personal digital assistant” or “PDA”, as defined above, means any handheld, mobile device that combines computing, telephone, fax, e-mail and networking features. The terms “wireless wide area network” or “WWAN” mean a wireless network that serves as the medium for the transmission of data between a handheld device and a computer. The term “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).
In wireless wide area networks, communication primarily occurs through the transmission of radio signals over analog, digital cellular, or personal communications service (“PCS”) networks. Signals may also be transmitted through microwaves and other electromagnetic waves. At the present time, most wireless data communication takes place across cellular systems using second generation technology such as code-division multiple access (“CDMA”), time division multiple access (“TDMA”), the Global System for Mobile Communications (“GSM”), Third Generation (wideband or “3G”), Fourth Generation (broadband or “4G”), personal digital cellular (“PDC”), or through packet-data technology over analog systems such as cellular digital packet data (CDPD”) used on the Advance Mobile Phone Service (“AMPS”).
The terms “wireless application protocol” or “WAP” mean a universal specification to facilitate the delivery and presentation of web-based data on handheld and mobile devices with small user interfaces. “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, Calif.), BREW (BREW is a registered trademark of Qualcomm Incorporated of San Diego, Calif.), Windows Mobile (Windows is a registered trademark of Microsoft Corporation of Redmond, Wash.), Palm OS (Palm is a registered trademark of Palm, Inc. of Sunnyvale, Calif.), Symbian OS (Symbian is a registered trademark of Symbian Software Limited Corporation of London, United Kingdom), ANDROID OS (ANDROID is a registered trademark of Google, Inc. of Mountain View, Calif.), and iPhone OS (iPhone is a registered trademark of Apple, Inc. of Cupertino, Calif.), and Windows Phone 7. “Mobile Apps” refers to software programs written for execution with Mobile Software.
The terms “scan, fiducial reference”, “fiducial location”, “marker,” “tracker” and “image information” have particular meanings in the present disclosure. For purposes of the present disclosure, “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 and a “scanner” is the means by which such scans are obtained. The term “fiducial reference”, “fiducial key”, or simply “fiducial” refers to an object or reference on the image of a scan that is uniquely identifiable as a fixed recognizable point. In the present specification the term “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. 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. In some embodiments, the tracker may be a non-stereo optical tracker, for example a camera. The camera may, for example, operate in the visible or near-infrared range. The term “image information” is used in the present specification to describe information obtained by the tracker, whether optical or otherwise, about one or more tracking markers and usable for determining the location of the markers and their orientation and movement continually in ‘real time’ during a procedure. The term “vectorized” is used in this specification to describe fiducial keys and tracking markers that are at least one of shaped and marked, or have a portion that is one of shaped and marked, so as to make their orientation in three dimensions uniquely determinable from their appearance in a scan or in image information. If their three-dimensional orientation is determinable, then their three-dimensional location is also known. Fiducial keys and tracking markers disclosed in this specification may have rotationally asymmetric shapes or bear rotationally asymmetric patterns of markings to render them vectorized.
All vectorized tracking markers employed in the present invention (for example 504, 507, 607 and 609 of
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. 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 234, as with other storage interfaces of computer system 210, may connect to standard computer readable media for storage and/or retrieval of information, such as fixed disk drive 244. Fixed disk drive 244 may be part of computer system 210 or may be separate and accessed through other interface systems. Modem 247 may provide direct connection to remote servers via telephone link or the Internet via an Internet service provider (ISP) (not shown). 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.
Many other devices or subsystems (not shown) may be connected in a similar manner (e. g., document scanners, digital cameras and so on), including the hardware components of
Moreover, regarding the signals described herein, those skilled in the art recognize that 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. Although the signals of the above-described embodiments are characterized as transmitted from one block to the next, other embodiments of the present disclosure may include modified signals in place of such directly transmitted signals as long as the informational and/or functional aspect of the signal is transmitted between blocks. To some extent, 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 modification 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 embodiments of surgical hardware and software monitoring systems and methods which allow 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, namely a vectorized fiducial reference, represented as fiducial key 10 in
In other embodiments additional vectorized tracking markers 12 may be attached to items independent of 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.
In a further embodiment 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 tracking marker 12 and of any other additional vectorized tracking markers relative to the scan data of the surgical area. By way of example, 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 vectorized markers to be tracked by the tracker attached to the item or instrument must be within the field of view of the tracker.
Using the dental surgery example, the patient is scanned to obtain an initial scan of the surgical site. The particular configuration of single 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
In addition, 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
In one embodiment, the computer system has a predetermined knowledge of the physical configuration of single 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 such 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. In other embodiments the material of the distinctive identifying and orienting markings may be created using suitable high density or radio-opaque inks or materials.
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.
In some embodiments, the monitoring hardware includes a tracking attachment to the fiducial reference. In the embodiment pertaining to dental surgery 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 pattern may be a rotationally asymmetric 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. For example, as particularly shown in
It is further possible to reorient the tracking pole during a surgical procedure. Such reorientation 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. For example, 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. Additionally, boundary conditions may be implemented in the software so that the user is notified when observational data approaches and/or enters the boundary areas.
The tracker of the system may comprise a single optical imager obtaining a two-dimensional image of the site being monitored. The system and method described in the present specification allow three-dimensional locations and orientations of tracking markers to be obtained using non-stereo-pair two-dimensional imagery. In some embodiments more than one imager may be employed as tracker, but the image information required and employed is nevertheless two-dimensional. Therefore the two imagers may merely be employed to secure different perspective views of the site, each imager rendering a two-dimensional image that is not part of a stereo pair. This does not exclude the employment of stereo-imagers in obtaining the image information about the site, but the system and method are not reliant on stereo imagery of the site.
In a further embodiment, the vectorized tracking markers may specifically have a three-dimensional shape. Suitable three-dimensional shapes bearing identifying patterns may include, without limitation, a segment of an ellipsoid surface and a segment of a cylindrical surface. In general, suitable three-dimensional shapes are shapes that are mathematically describable by simple functions.
The term “identifiably unique” is employed in the present specification to describe a pattern that is distinct from patterns on any other tracking markers employed with the system and may be uniquely identified with a particular tracking marker for the purposes of identifying the marker, both when it is used alone and when used in conjunction with other pattern-bearing tracking markers. The term “pattern reference point” is employed in the present specification to describe a consistently identifiable point within the rotationally asymmetric pattern on a tracking marker that may be employed in determining a coordinate system for purposes of describing the three-dimensional locations and orientations of elements of the tracking system. The rotationally asymmetric pattern may comprise pattern elements having contrast with respect to a background.
In a further embodiment of the system utilizing the invention, a surgical instrument or implement, herein termed a “hand piece” (see
An alternative embodiment of some hardware components are shown in
The materials of the hardware components may vary according to regulatory requirements and practical considerations. Generally, 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. In addition, because it is generally located on the patient, the material should be lightweight and suitable for connection to an apparatus on the patient. For example, in the dental surgery example, the materials of the fiducial key must be suitable for connection to a plastic splint and suitable for connection to a tracking pole. In the surgical example the materials of the fiducial key may be suitable for attachment to the skin or other particular tissue of a patient.
The vectorized tracking markers may be 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 second material may be chosen for its ability to be clearly imaged during a scan of the type described above. In this respect it should be noted that medical scanning systems are often optimized in terms of, for example, their scan contrast, scan brightness and scan gamma in detecting biological materials such as human bone. Fiducials are therefore typically made of radio-opaque materials capable of producing suitable contrast during a scan optimized for biological materials. Suitable materials as choice for the second material in
While the physical outline of fiducial reference 10″ in
As explained in the foregoing sections of this specification, suitable tracking attachments may be attached to reference 10″ via hole 15″. In the embodiment pertaining to dental surgery the tracking attachment to fiducial key 10″ is tracking marker 12, which is attachable to fiducial key 10″ via a suitable tracking pole, for example tracking pole 11. Holes 18 in fiducial reference 10″ are employed to provide more adhesion for the dental putty employed in fitting fiducial reference 10″ to the teeth of the patient.
In
As in the case of
In embodiments based on the principles and elements elucidated in
In the multi-material embodiments based on
The term “accuracy” is employed in this specification to describe the closeness of the placement of a scan-detectable element to its intended placement. The term “precision” is used to describe the repeatability of the placement of a scan-detectable element. Due to the accuracy and precision with which scan-detectable elements 13a, 13b, 13c, and 13d of fiducial key 10″ in
In exemplary tracking systems made by the inventors, the surgical accuracy that enables the user-calibration-free aspect of the tracking system, tracking markers and fiducial reference is achieved by positioning the scan-detectable elements within the fiducial reference during the manufacture of the latter to an accuracy of better than 150 microns. That is, the placement of any point on or in a scan-detectable element is within +/−150 microns of its specified placement position. The precision at 150_micron accuracy is 100%. That is, every point on or in every scan-detectable element is within 150 microns of its specified placement position.
In dental surgery, the relationship between the accuracy of the placement of the scan-detectable elements and the accuracy of the surgery is determined by the ratio between the distance from one of the scan-detectable elements to the rearmost teeth, on the one hand, to the shortest distance between scan-detectable elements in the fiducial reference on the other hand. The resulting ratio, which refer to as a “lever ratio” in the present specification, creates by a lever action an accuracy that is on the order of six times worse at the third lower adult human molar as compared with the accuracy at the fiducial attached to one of the lower adult human central incisors. This implies that a +/−150 micron placement accuracy of the scan-detectable element in the fiducial reference at the lower central incisor results in an accuracy of +/−900 microns at the third lower molar. This accuracy is generally deemed suitable for use in dental surgery. Other sources of inaccuracies may however be compounded with the inaccuracy in placement of the scan-detectable elements in the fiducial reference to render the overall accuracy of the system as whole outside the limit of +/−
In further, more developed exemplary tracking systems, the placement accuracy is better than +/−80 microns with a 100% precision. This leads to an accuracy of +/−480 microns at the third lower molar. This is an accuracy that is generally safely acceptable in surgical practice.
In yet further exemplary tracking systems, the placement accuracy is better than +/−40 microns with a 100% precision. This leads to an accuracy of +/−240 microns at the third lower molar. This is an accuracy that is generally deemed to be the best that may be achieved by hand, making the system of the present invention comparable in accuracy to the very best that may be achieved by hand.
In yet further exemplary tracking systems, the placement accuracy is better than +/−16 microns with a 100% precision. This leads to an accuracy of +/−96 microns at the third lower molar. This is an accuracy that is generally deemed to represent negligible deviation so that any inaccuracy introduced by the placement of the scan-detectable elements in the fiducial reference effectively disappears in comparison to other sources of inaccuracy.
In the present specification, the four levels of accuracy compatible with human surgery described above may be attained with 100% precision for the fiducial reference of the present invention by the methods described below.
The embodiments shown in
To achieve the abovementioned placement accuracies of the scan-detectable elements within the fiducial references, the fiducial reference is formed around the scan-detectable elements while the scan-detectable elements are held rigidly in place. In the case of injection molding, the pre-made scan-detectable elements may be held rigidly in position to the abovementioned accuracies within the mold while the fiducial reference is injection-molded around them. One non-limiting example of a method for holding the scan-detectable elements rigidly in place is by using at least one pin, in some embodiments multiple pins. In those cases where the scan-detectable elements are wholly surrounded by the material of the fiducial reference, more than one injection molding step may be required. In the first step, the scan-detectable elements are embedded but not wholly surrounded. In a second injection step the rest of the fiducial reference is formed while the scan-detectable elements remain rigidly held in place by the injection molded material of the first injection molding step. Placement accuracies as good as +/−16 microns may be obtained with 100% precision for the scan-detectable elements within the fiducial references by this method of manufacture, as one of skill in this art of manufacturing would recognize. We return later to this method.
The tracker employed in tracking the fiducial keys, tracking poles and tracking markers may be capable of tracking with suitable accuracy objects of a size of the order of 1.5 square centimeters. 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. The tracker may be a non-stereo optical tracker.
In embodiments that additionally employ a trackable piece of instrumentation, such as a hand piece, vectorized 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 engraved or attached and a rigid, quick mounting mechanism to a standard hand piece.
In another aspect there is presented an automatic registration method for tracking surgical activity, as illustrated in
Once the process starts [402], as described in
Turning now to
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 [454] the three-dimensional orientation of the fiducial reference based on the image information and the registration process ends [456]. In order to monitor the location and orientation of the fiducial reference in real time, the process may be looped back from step [454] to obtain new image information from the camera [at step 442]. A suitable query point may be 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 vectorized 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.
One example of an embodiment of the invention is shown in
In some embodiments, controller 520 may also control instrument or implement 506 and guide it to execute the surgical process based on image information that tracker 508 supplies to controller 520 and, thereby, on the scan data from an earlier scan. Such surgical processes are generally known as “robotic surgery”. As in the above embodiments, the image information of marker 504 allows determination of the three-dimensional location and orientation of fiducial marker 502 for which a prior scan has provided scan data for use by controller 520. In such embodiments, computer software stored in memory 217 of
Another example of an embodiment of the invention is shown in
In the embodiment of
In both of these robotic implementations the controller may operate on an autonomous basis, with human intervention being optional. Fiducial 502, 602 remains rigidly attached to the surgical site, and the marker 504, 604 remains in its fixed relative position and orientation with respect to fiducial 502, 602 if and when the patient moves. With both markers 504 and 507 in
The term “geometric information” is employed in the present specification to describe the collection of information regarding the shapes, sizes, perimeters, distribution, and the like of elements of the patterns on the tracking markers. The geometric information may include information on the pattern reference points of the patterns. A suitable pattern reference point on tracking marker 504 of
The automatic registration method for tracking surgical activity as per the present embodiment employing the pattern tags as described herein comprises the steps [402] to [456] of
The rotationally asymmetrical tracking marker arrangements described here may be applied to other fields of general machine vision and product tracking beyond the field of surgery. More specifically, while vectorized tracking marker 12 has been described in terms of being attached to fiducial key 10 by tracking pole 11 (see for example
In a further aspect, as shown at the hand of the flow chart in
The geometric information may further comprise information about a second tracking marker bearing at least one second identifiably unique rotationally asymmetric pattern and the method may further comprise: removably and rigidly attaching [1614] to a location proximate the surgical site a single passive vectorized fiducial reference; obtaining [1616] scan data of the surgical area with the fiducial reference attached to the location, removably and rigidly attaching [1618] to the fiducial reference the second tracking marker in fixed three-dimensional spatial relationship with the fiducial reference, identifying [1655] the second tracking marker in the image information on the basis of the at least one second unique pattern; determining [1665] within the image information the location of at least one second pattern reference point of the second tracking marker based on the geometric information; determining [1675] within the image information a rotational orientation of the second tracking marker based on the geometric information; and further guiding [1685] the robotic surgery instrument based on the scan data, on the location of the at least one second pattern reference point, and on the rotational orientation of the second tracking marker.
In some implementations of the method, the fiducial reference may itself bear the second tracking marker, so that the step of attaching [1618] to the fiducial reference the second tracking marker in fixed three-dimensional spatial relationship with the fiducial reference is obviated.
A method for manufacturing the multi-material fiducial references of
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
The present application claims the benefit under 35 U.S.C. § 119(e) of provisional applications 62/466,996 and 62/142,194, filed Mar. 3, 2017 and Oct. 24, 2016, respectively, and claims the benefit under 35 U.S.C § 120 as a continuation-in-part of U.S. patent application Ser. No. 13/822,358, filed Mar. 13, 2013, which is the United States National Stage application under 35 U.S.C. § 371 of International Patent Application PCT/IL2012/00036, filed Oct. 23, 2012, which claims the benefit under 35 U.S.C. § 119(e) of Provisional Patent Applications Ser. Nos. 61/533,058; 61/616,718; and 61/616,673; filed on Oct. 28, 2011; Mar. 28, 2012; and Mar. 28, 2012, respectively, the disclosures of which are incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62466996 | Mar 2017 | US | |
| 62142194 | Apr 2015 | US | |
| 61533058 | Sep 2011 | US | |
| 61616718 | Mar 2012 | US | |
| 61616673 | Mar 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13822358 | Mar 2013 | US |
| Child | 15788826 | US |
