Stereotactic computer assisted surgery based on three-dimensional visualization
Abstract
A method for operating a computer-assisted surgical system for stereotactic surgery, comprising: diagnosing an area of interest (640) and a medical device (610, 1654) related to a reference body (604) close to the image. region of interest of a portion of an anatomy of a subject at two or more angles to obtain a plurality of two-dimensional images (910, 920); process the plurality of two-dimensional images to produce three-dimensional information related to the region of interest; associating, based on the three-dimensional information, a virtual medical device (1666) with the region of interest in a predetermined relationship with respect to the reference body (604); and show the association as an image showing the virtual medical device (610) superimposed on the region of interest (640), in which the procedure does not include the steps of placing the medical device (610, 1654) and in which the The procedure does not include the step of repositioning the medical device as long as it constitutes a treatment of the human body or of an animal by surgery.

Term
2.3 yearsto projected expiry
Projected expiry 9 January 2029, counted from filing; an application has no term until it is granted.
- Priority
- Filed
- Published
- Today
- Projected expiry
19 claims: 6 independent, 13 dependent
- 1ES 2 397 807 T3 REIVINDICACIONES 1. Un procedimiento para poner en funcionamiento un sistema quirúrgico asistido por ordenador para cirugía estereotáctica, que comprende:diagnosticar por imagen una región de interés (640) y un dispositivo médico (610, 1654) relacionado con un cuerpo de referencia (604) próximo a la región de interés de una porción de una anatomía de un sujeto a dos o más ángulos para obtener una pluralidad de imágenes bidimensionales (910, 920);procesar la pluralidad de imágenes bidimensionales para producir información tridimensional relacionada con la región de interés;asociar, en base a la información tridimensional, un dispositivo médico virtual (1666) con la región de interés en una relación predeterminada con respecto al cuerpo de referencia (604);y mostrar la asociación como una imagen que muestra el dispositivo médico virtual (610) superpuesto sobre la región de interés (640), en el que el procedimiento no comprende las etapas de colocar el dispositivo médico (610, 1654) y en el que el procedimiento no comprende la etapa de recolocar el dispositivo médico en tanto que constituya un tratamiento del cuerpo humano o de un animal mediante cirugía.
- 2El procedimiento de la reivindicación 1, que comprende adicionalmente detectar la presencia del cuerpo de referencia (604) en base a uno o más marcadores fiduciales (616).
- 3El procedimiento de la reivindicación 1 ó 2, en el que el diagnóstico por imagen comprende adquirir dos imágenes fluoroscópicas (910, 920) de la región de interés a dos ángulos diferentes.
- 4El procedimiento de cualquiera de las reivindicaciones 1 a 3, en el que el procesamiento comprende adicionalmente estimar el contorno de la región de interés en al menos dos dimensiones en base a la pluralidad de imágenes bidimensionales (910, 920).
- 5El procedimiento de la reivindicación 4, en el que el procesamiento comprende adicionalmente formar una imagen tridimensional relacionada con la región de interés (640) en base a la estimación.
- 6El procedimiento de la reivindicación 4 ó 5, en el que la región de interés (640) comprende una cabeza femoral, la pluralidad de imágenes bidimensionales comprende imágenes anteroposteriores y axiales de la región femoral y la estimación comprende formar un contorno de la cabeza femoral en las imágenes anteroposterior y axial.
- 7Programa informático para hacer funcionar un sistema quirúrgico asistido por ordenador para cirugía estereotáctica, comprendiendo el sistema un aparato para diagnosticar por imagen una región de interés, comprendiendo el programa informático conjuntos de instrucciones al ejecutar el sistema quirúrgico asistido por ordenador configurado para:diagnosticar por imagen una región de interés (640) y un dispositivo médico (610, 1654) relacionado con un cuerpo de referencia (604) próximo a la región de interés de una porción de una anatomía de un sujeto a dos o más ángulos para obtener una pluralidad de imágenes bidimensionales (910, 920);procesar la pluralidad de imágenes bidimensionales para producir información tridimensional relacionada con la región de interés;asociar, en base a la información tridimensional, un dispositivo médico virtual (1666) con la región de interés en una relación predeterminada con respecto al cuerpo de referencia (604);y mostrar la asociación como una imagen que muestra el dispositivo médico virtual (610) superpuesto sobre la región de interés (640).
- 8Programa informático de la reivindicación 7, que comprende adicionalmente conjuntos de instrucciones para detectar la presencia del cuerpo de referencia (604) en base a uno o más marcadores fiduciales (616).
- 9Programa informático de la reivindicación 7 ó 8, en el que el diagnóstico por imagen comprende adquirir dos imágenes fluoroscópicas (910, 920) de la región de interés a dos ángulos diferentes. ES 2 397 807 T3
- 10Programa informático de cualquiera de las reivindicaciones 7 a 9, en el que el procesamiento comprende adicionalmente estimar el contorno de la región de interés en al menos dos dimensiones en base a la pluralidad de imágenes bidimensionales (910, 920).
- 11Programa informático de la reivindicación 10, en el que el procesamiento comprende adicionalmente formar una imagen tridimensional relacionada con la región de interés (640) en base a la estimación.
- 12Programa informático de la reivindicación 10 u 11, en el que la región de interés (640) comprende una cabeza femoral, la pluralidad de imágenes bidimensionales comprende las imágenes anteroposterior y axial de la región femoral y la estimación comprende formar un contorno de la cabeza femoral en las imágenes anteroposterior y axial.
- 13Un sistema quirúrgico asistido por ordenador, que comprende:un aparato para diagnosticar por imagen una región de interés (640) de una porción de una anatomía de un sujeto;una memoria que contiene instrucciones ejecutables;y un procesador programado que usa las instrucciones para: recibir dos o más imágenes bidimensionales (910, 920) de la región de interés y un implante (610, 1654) situado en la región de interés tomadas a diferentes ángulos del aparato, procesar las dos o más imágenes bidimensionales para producir información tridimensional relacionada con la región de interés y del implante situado en la región de interés, superponer un implante virtual sobre la región de interés en una relación fija predeterminada con respecto al implante colocado en base a la información tridimensional para formar una imagen, mostrando así la posición del implante virtual (1666) con respecto a la región de interés, y generar una señal de visualización relacionada con la imagen superpuesta.
- 14El sistema de la reivindicación 13, en el que el aparato comprende un fluoroscopio.
- 15El sistema de la reivindicación 13 ó 14, que comprende adicionalmente un sub-implante virtual (1666) relacionado la región de interés y el implante virtual de tal forma que el sub-implante virtual proporcione una estimación de la ubicación de un implante real (610, 1654) y uno o más sub-implantes en la región de interés.
- 16El sistema de cualquiera de las reivindicaciones 13 a 15, en el que el procesador procesa una o más imágenes bidimensionales delineando el contorno de la región de interés en dos dimensiones y crea un objeto tridimensional que representa la región de interés.
- 17El sistema de la reivindicación 16, en el que el objeto tridimensional comprende una esfera.
- 18El sistema de la reivindicación 16 ó 17, en el que el objeto tridimensional se obtiene de una base de datos y en base a la edad y el género del paciente.
- 19El sistema de cualquiera de las reivindicaciones 13 a 18, en el que el objeto tridimensional se determina en base a puntos de referencia relacionados con la región de interés.
Independent claims19
116 paragraphs in 8 sections, as filed
ES 2 397 807 T3
DESCRIPTION
Computer-assisted stereotactic surgery based on three-dimensional visualization.
Background of the invention
The invention relates to a computer-assisted surgery (CAS) system and procedure that uses stereotactic navigation with three-dimensional visualization, and more specifically to a CAS system that is reactive and does not alter the operation of operating room workflow procedures. .
A current implant insertion procedure (consisting of, for example, a plate and related screws) is typically performed by positioning the plate in the corresponding anatomical location and inserting the screws with the aid of fluoroscopy. Plate implantation and fixation systems is often a difficult task as operating room (OR) procedures are generally minimally invasive and therefore their placement is achieved by trial and error using fluoroscopy, such as, a C-arm appliance, that is, C-arm vision. This generally leads to a prolongation of the operation. Furthermore, during such a procedure, both the patient and the operator are exposed to significant amounts of radiation.
Furthermore, in some cases it may be impossible to determine the position of implant components (eg screws in bone) with sufficient precision because the fluoroscopic image is only two-dimensional. This leads to misplacing or the insertion of screws of an inappropriate length. This, in turn, can cause high revision rates or even injury (for example, a hip joint injury). In order to ensure that these implant components do not extrude the bone, therefore, it is often necessary to locate these implant components with an excessively large margin of error away from the edge of the bone. In many cases, the result is that the implant cannot be positioned as intended, and the desired biomechanical stability cannot be achieved. In the case of femoral neck fractures, for example, the use of conventional fluoro-navigation does not result in any significant improvement.
Other state-of-the-art technologies are currently used in operating rooms to facilitate surgery, including intraoperative three-dimensional (3D) imaging and tracking technology-based navigation systems. However, only a few hospitals use these technologies. The limited adoption of these technologies is primarily due to their high cost, the effort involved in installing these systems, and the resulting significant changes to operating room procedures or workflow. For example, tracking technologies require a line of sight between the tracking device and the navigation detection system. This disrupts the normal workflow as the surgeon and other personnel must then remain attentive to the line of sight requirements of the system.
Furthermore, generally, successful placement of a primary implant, such as a plate or nail, cannot be defined preoperatively. For example, during an operation the placement can be done by tactile correspondence on the bone surface or by drilling the bone to make room for an intramedullary nail. Furthermore, although the opposition of the sub-implant or sub-implants may be based solely on preoperative images (eg fluoroscopy or CT images), said position is still relative to the position of the main implant. Therefore, a preoperative placement procedure cannot be fully planned, but must be optimized during the operation. In this regard, a conventional stereotaxis cannot be used due to the fact that the position cannot be predefined.
Accordingly, there is a need for a computer-assisted surgery (CAS) system that improves surgical procedures without significantly disrupting normal operating room workflow. More specifically, there is a need for a combined 3D imaging and CAS system that can be easily and easily integrated into the clinical environment. Preferably, such a system will be low cost, easy to install and use, and minimize changes to the operating room workflow.
Document WO2005 / 087125 describes an integrated surgical system that includes a subject holder and / or a wireless magnetic tracking system and / or a recording system configured to record the position of the subject's body part with an image of the subject. of the subject's body and / or a display device and / or a control system that integrates the functionalities of the parts of the surgical system and / or an interface for the surgeon manageable by the surgeon to control the operation of the integrated surgical system.
Summary
One aspect of the present invention is a reactive method for operating a computer-assisted surgical system (CASS), a computer program for operating a CASS and a CASS in accordance with the subject matter of the independent claims. The procedure generally comprises detecting information related to the implant using a diagnostic imaging system;
ES 2 397 807 T3 determine, based on the information detected related to the implant, the action to be taken as part of the surgery; and display the positional information related to the implant and the region of interest based on the action to be taken.
In accordance with this aspect of the present invention, the invention comprises acquiring two fluoroscopic images of the region of interest at two different angles.
Additionally, in accordance with this aspect of the present invention, the visualization further comprises processing the detected information related to the implant by estimating the contour of the region of interest in at least two dimensions based on the plurality of two-dimensional images.
Still further in accordance with this aspect of the present invention, the detection comprises detecting the presence of the reference body based on one or more fiducial markers.
In accordance with an aspect useful for understanding the invention, the method comprises positioning a reference body-related medical device proximate to a region of interest of a portion of a subject's anatomy and imaging the region of interest in two or more angles to obtain a plurality of two-dimensional images. In an exemplary embodiment, the reference body comprises a plurality of fiducial members, more preferably at least four of said markers that are visible to the diagnostic imaging system. It is further preferred that the fiducial markers comprise spheres that are visible to the imaging system.
In accordance with this aspect of the present invention, the plurality of two-dimensional images are processed to produce three-dimensional information related to the region of interest. Furthermore, the method preferably further includes associating, based on the three-dimensional information, a virtual medical device with the region of interest and the reference body and displaying the association as an image showing the virtual medical device superimposed on the region of interest.
Additionally, in accordance with this aspect of the present invention, the virtual medical device comprises a main implant and one or more sub-implants. In addition, the virtual main implant is superimposed on the current location of the real implant and the virtual sub-implants are generated to show their future position. Consequently, virtual sub-implants inform the surgeon of where the actual sub-implant will be located before it is placed in the region of interest.
In accordance with this aspect of the present invention, diagnostic imaging preferably comprises acquiring two fluoroscopic images of the region of interest at two different angles. Furthermore, the processing preferably further comprises estimating the outline of the region of interest in at least two dimensions based on the plurality of two-dimensional images.
Additionally, in accordance with this aspect of the present invention, the processing may further comprise forming a three-dimensional image related to the region of interest based on the estimation. In a further preferred aspect, the present invention may be applied to a surgical implant procedure in which the region of interest comprises a femoral head, the plurality of two-dimensional images comprise the anteroposterior and axial images of the femoral region, and the estimation comprises forming a contour of the femoral head in the anteroposterior and axial images. In this regard, the method may further comprise forming parts of a three-dimensional sphere representing significant portions of the femoral head.
Furthermore, the medical device preferably comprises an intracapsular plate and the reference body is connected to the plate, and positioning comprises positioning the intracapsular plate in a femur proximate the femoral head. Furthermore, the virtual medical device preferably comprises a virtual intracapsular plate, and the display comprises showing the virtual intracapsular plate superimposed on the position of the intracapsular plate relative to the femoral head.
In another aspect, the present invention is a computer-assisted surgical system comprising: an apparatus for imaging a region of interest from a portion of a subject's anatomy; a memory containing executable instructions; and a programmed processor that uses instructions to perform a procedure. In this regard, the processor preferably receives two or more two-dimensional images of the region of interest taken at different angles of the apparatus, processes the two or more two-dimensional images to produce three-dimensional information related to the region of interest, superimposes a virtual reference body on the region of interest based on the three-dimensional information to form an image showing the reference and virtual body with respect to the region of interest, and generates a display signal related to the superimposed image. Preferably, the reference body is first detected and superimposed on an object that models the region of interest, eg, a sphere for a femoral head; and then the
ES 2 397 807 T3 display signal after.
In accordance with this aspect of the present invention, the processor preferably processes one or more of the two-dimensional images outlining the outline of the region of interest in two dimensions and creates a three-dimensional object representing the region of interest. The three-dimensional object can be obtained from a database based on the age and gender of the patient. The three-dimensional object can also be determined based on reference points related to the region of interest.
Additionally, in accordance with this aspect of the present invention, a medical device may comprise a device selected from the group consisting of an intracapsular plate, an artificial joint, a pacemaker, and a valve.
In another aspect, the present invention is a computer-assisted surgery (CAS) system using stereotactic navigation with three-dimensional visualization, in which an implant, or a system of implants, acts as a stereotactic device. The invention provides a reactive CAS system designed for use with monoaxial and polyaxial plates and nails. Based on the principles of stereotactic correspondence and 2D-3D, a system is provided that virtually suggests or gives an indication of the optimal position of an implant by calculating said position. In addition, the system can also calculate screw lengths before drilling. Aided by image processing and virtual 3D visualization, the system can achieve optimal biomechanics.
Furthermore, unlike existing navigation systems, the CAS system of the present invention is designed to be reactive in order to reduce any additional effort for the surgeon. In particular, the system can be triggered by the use of a reference body, implant K-wires, or screws that are normally used as part of the surgical procedure. Furthermore, by detecting these devices, the system is able to determine the stage of the workflow that is being carried out. More specifically, image processing is used to detect various objects during the workflow and determine which stage is being performed by the surgeon and for adaptation of the system.
In another aspect, the system provides necessary 3D information without the need for intraoperative 3D imaging (eg, 3D C-arms). The system is also inexpensive, easy to install and use, and minimizes changes to the OR workflow. The present system also requires few X-ray images and is therefore safe for patients.
An iterative procedure (using for example an ICP to fix a fracture of the neck of the femur) includes one or more of the following steps:
1. Placing an implant in an anatomical region of interest, eg, based on satisfactory haptic correspondence;
2. Diagnose by fluoroscopic imaging the anatomical region of interest;
3. Virtually check the future position of the sub-implant or sub-implants;
Four. Virtually realign the implant according to the constraints until a satisfactory virtual position is reached;
5. Provide active or passive realignment values for implant placement for the surgeon (ie, actively identifying the best location or passively allowing the surgeon to decide);
6. Actual plate realignment by surgeon based on realignment values and satisfactory haptic correspondence; Y
7. Begin the two-stage iteration procedure until the operation is complete.
These additional aspects and features of the present invention are described in further detail below.
Brief description of the drawings
Figure 1A illustrates a computer-assisted stereotactic surgical system in accordance with one aspect of the present invention.
Figure 1B depicts a computer that can be used in the system of Figure 1 in accordance with one aspect of the present invention.
Figure 2 illustratively depicts how a conventional two-dimensional (2D) image may not accurately show screw positions in a region of interest.
Figure 3 illustratively depicts how three-dimensional imaging can be used to represent positional information that is not apparent with conventional two-dimensional images. Figure 4A is a flow chart illustrating a procedure for implanting a medical device.
ES 2 397 807 T3
Figure 4B is a flow chart illustrating a procedure for placing an implant.
Figure 4C is a flow chart illustrating a procedure for generating a virtual image of an implant and a region of interest.
Figure 5 shows the placement of an intracapsular plate implant.
Figure 6A is a side view of an implant system including a reference body and an implant in accordance with one aspect of the present invention.
Figure 6B is a perspective view of a reference body and an implant in accordance with one aspect of the present invention.
Figure 6C is a perspective view of a reference body and an implant in accordance with one aspect of the present invention.
Figure 7 illustrates the placement of an intracapsular plate implant on a femur.
Figure 8 illustratively represents the step of taking two fluoro shots from different angles.
Figure 9 illustrates the detection of the femoral head in the two fluoroshoots.
Figure 10 illustrates the visualization of a virtual three-dimensional sphere representing the head of the femur based on conical projections of the two-dimensional fluoroshoots.
Figure 11 shows the step of showing a display based on a correspondence of the three-dimensional sphere with the two-dimensional images.
<td>Figure 12A shows an intracapsular stage in the distal direction.</td><td>of</td><td>adjust</td><td>automatically</td><td>the</td><td>position</td><td>proposal</td><td>of</td><td>the</td><td>license plate</td>
<td>Figure 12B shows an intracapsular stage in the distal direction.</td><td>of</td><td>adjust</td><td>automatically</td><td>the</td><td>position</td><td>proposal</td><td>of</td><td>the</td><td>license plate</td>
<td>Figure 13A shows an intracapsular stage by external rotation.</td><td>of</td><td>adjust</td><td>automatically</td><td>the</td><td>position</td><td>proposal</td><td>of</td><td>the</td><td>license plate</td>
<td>Figure 13B shows an intracapsular stage by external rotation.</td><td>of</td><td>adjust</td><td>automatically</td><td>the</td><td>position</td><td>proposal</td><td>of</td><td>the</td><td>license plate</td>
Figure 14 shows the repositioning and fixation of the intracapsular plate based on the proposed position.
Figure 15 shows automatic K-wire insertion detection and femur head movement detection to ensure reactive behavior.
Figures 16A-16H illustrate the use of the method of Figure 4.
Detailed description
Generally, in one aspect, the system of the present invention is based on fluoroscopic image registration with an implant related to a reference body. For example, the implant (eg, an angle stable plate) may include the reference body or it may be positioned at a predefined location relative to the reference body, which is detected or recorded on a fluoroscopic image. Therefore, the actual spatial dimension and position of the implant can be determined by correct identification and registration of the reference body on fluoroscopic images.
When multiple related implants are included as part of the procedure, for example main implants and sub-implants, after registration of the main implant as described above, the location of any remaining sub-implants can be represented in virtually the correct spatial position with compared to fluoroscopic images of the main implant. Sub-implants (eg, related angle stable plate screws) will be placed in a fixed predefined position relative to the main implant after all implants have been implanted.
In order to provide the necessary information for an anatomically correct location of all implants (main and sub-implants), important anatomical regions are approximated using three-dimensional bodies or objects represented on the fluoroscopic image in the correct relative position. The target values are compared to the values for the location of the remaining implants, which are used to determine the current position of the main implant.
During preoperative planning (for example, using a non-invasive applied reference body), partial or sub-implants (for example, screws) can be placed first in an optimal position, independent of the location of the main implant (plate ). In a subsequent operation (using an invasive reference body), where the location of the main implant has been determined by preoperative planning (with an estimate of the position derived by the surgeon), the location of a main implant can be optimized using a reaction tactile. After registration as described above, the resulting location of the partial or sub-implant implants is rendered virtually; this position is compared with the position of the partial implant in the preoperative plan and with the distances to important anatomical (three-dimensional) structures. In a reactive iterative process (adjusting the plate as instructed by the system), it is possible to determine the optimal balance between an ideal primary implant location (e.g., plate housing) and the ideal partial implant position (e.g., screw location).
ES 2 397 807 T3
Turning now to FIG. 1A, a computer-assisted stereotactic surgical (CAS) system 100 is illustrated in accordance with one aspect of the present invention. As shown, in the preferred embodiment, the system 100 includes an imaging apparatus 110, such as a C-arm fluoroscope, and a computing device 120, such as a laptop computer. In general, computing device 120 contains a processor 150, memory 160, and other components typically present in general purpose computers as depicted in FIG. 1B.
Memory 160 stores information accessible by processor 150, via bus 162, for example, including instructions 164 for execution by processor 150 and data 166 that is retrieved, manipulated, or stored by processor 150. Memory 160 can be of any type capable of storing information accessible by processor 150, such as a hard disk, ROM, RAM, CD-ROM, rewritable, read-only, or the like. Instructions 164 can comprise any set of instructions that will be executed directly (such as machine code) or indirectly (such as scripts) by the processor. In this regard, the terms instructions, steps, and programs may be used interchangeably in this document. The functions, procedures and routines of the program according to the present invention are explained in more detail below.
Data 166 can be retrieved, stored, or modified by processor 150 in accordance with instructions 164. The data can be stored as a collection of data. For example, although the invention is not limited to any particular data structure, the data may be stored in computer records, in a relationship database as a table having a plurality of different fields and records, or in the form of a XML document. The data can also be formatted in any computer-readable format such as, but not limited to, binary values, ASCII, or EBCDIC (Extended Binary Code Decimal Interchange Code). In addition, any information sufficient to identify the relevant data can be stored along with the data, such as descriptive text, owner codes, indicators, or information that is used by a function to calculate the relevant data.
Although processor 150 and memory 160 are functionally illustrated in Figure 1B within the same block, it will be understood by those skilled in the art that processor 150 and memory 160 may actually comprise multiple processors and memories that may or may not be stored within the same physical accommodation. For example, some or all of the instructions 164 and data 166 may be stored on a removable CD-ROM and others on a read-only computer chip. Additionally, some or all of instructions 164 and data 166 may be stored at a location physically remote from, and still accessible by, processor 150. Similarly, processor 150 may actually comprise a collection of processors that may or may not function in parallel.
As shown, computing device 120 may comprise additional components typically found in a computing system, such as a display (eg, LCD screen), user input (eg, keyboard, mouse, controller for video games, touch screen), a microphone, a modem (for example, a telephone or cable modem), and all other components used to connect these items together.
As also shown in FIG. 1A, a patient 185 will typically be positioned on an operating table with various limitations such that the area to be operated on has limited movement during surgery. The fluoroscope 110 (or other suitable imaging device) is used to image the region of interest of the patient's anatomy, for example, the region to be operated on or the area to be fixed. implant. As discussed in more detail below, an illustrative region of interest may comprise an area that includes the femoral neck and an intracapsular plate (ICP). Computer 120 (or other suitable visualization and image processing apparatus) is used to process the fluoroscope images, determine the position of the implant and sub-implants, and provide reactions / instructions to the surgeon. The processing steps performed by the computer are described below.
In another aspect, the present invention addresses the problem with current ICP implantation technique of accurately positioning the plate using two-dimensional (2D) images. This problem is due in part to the dangerous screw placement required to avoid cuts. Specifically, the ends / tips of the screws should fit as close to the second cortex as possible. However, the 2D images used by the surgeon do not reflect the 3D nature of the problem.
Figure 2 shows common drawbacks of a conventional two-dimensional (2D) image. In particular, a 2D image 200 may not indicate improper screw placement. In this case, the 2D image 200 makes the screw appear to be positioned correctly within the bone. However, a 3D illustration can provide additional information showing that a screw may have actually pierced the bone. For example, Figure 3 illustrates how 3D imaging can show a problem with screw placement that is not apparent with conventional 2D imaging. In Figure 3 none of the 2D images 300, 310 show a problem with the screw position. However, if the 2D images are combined to
ES 2 397 807 T3 create a 3D visualization, it is evident that the screw tip projects through the bone as illustrated at 320. Therefore, the 2D imaging currently performed on the surgeon may not always accurately reflect the location and position of medical devices and the like within a region of interest. Therefore, in this example, it will be beneficial for the surgeon to have access to 3D imaging.
In one aspect, the present invention provides a system and method that generates 3D information from 2D images to allow more accurate placement of a medical device, eg, an implant, and thus avoid the above problems. Generally, as used herein, the term "medical device" includes any biomedical device or structure that is inserted or implanted into the anatomy of a subject. Such devices include those that replace or act as lost biological structures, or that are placed on or within bones or portions of the anatomy. As mentioned above, the present invention is described using the illustrative example of implanting an intracapsular plate (ICP) to repair a femoral neck fracture. However, it is to be noted that the invention can find application in numerous surgeries, including virtually all fields of bone surgery (eg, traumatology, orthopedics, and pediatrics).
By way of background, it is generally known that fractures are normally repaired by reduction and fixation of broken bones. The individual bone fragments are aligned in their normal anatomical position (ie, reduced) so that the separated parts can grow together again. It is necessary that the parts remain relatively stable with respect to each other for a prolonged period of time to allow healing. In some cases, particularly for more complicated fractures, it is necessary to connect the individual fractured broken bone pieces directly to each other. In these cases, the fracture is fixed or reduced through an invasive procedure in which an implant is installed into the bone with screws or nails.
Returning to FIG. 4A, a high-level flow chart 400 of the procedural steps for implanting an implant is depicted.
As shown, the procedure begins with the placement of a primary implant in a region of interest, at step S402. As explained in more detail below, this initial placement is preferably done using fluoroshots taken along at least two dimensions or directions. Once the implant is placed to the satisfaction of the surgeon, the system 100 generates an image showing the position of a virtual implant and related virtual sub-implants relative to the region of interest, step S408 based on fluoroshoots and position. of a reference body or reference objects within the field of view of the fluoroscope 110.
Using the image of the virtual implants, the surgeon can then fix the implant, using the sub-implants, for example, as depicted in S424. Once the sub-implants (eg screws) and implants are in place, the system can perform a quality check, at S428, by detecting and displaying the actual location of these implants relative to their desired position. This quality check desirably occurs during implantation, the position of an implant or sub-implant may change from its ideal position due to mechanical forces during, for example, drilling or screw placement, or as a result of movement. of the patient. In this regard, quality checks, such as in step S428, can also be performed during fixation of an implant, in step S424. Additionally, quality checks can also be performed postoperatively using the system to detect movement in the implant caused by patient activity, for example.
Significantly, the above procedure 400 is reactive in that the surgeon is not required to inform the system 100 of what stage they are performing as part of the operating room workflow. In this regard, this system 100 is compatible with the normal operating room workflow and is capable of determining the operating room workflow stage being performed, for example, by detecting the presence of a reference body or object.
Turning now to FIG. 4B, the substeps or a procedure for positioning or aligning the implant is depicted in accordance with step S402 of FIG. 4A. As shown, the procedure begins with the insertion and placement of the main implant in the anatomical region of interest at step S430. Consistent with the illustrative example, an intracapsular plate (ICP) is used to repair femoral neck fractures. Therefore, in step S430, the ICP will be inserted into the patient and placed roughly on the bone, in this case the femoral neck. This step can be done, for example, in accordance with normal operating room workflow, such as allowing the doctor to use tactile feedback to determine an appropriate starting position for the plate.
In this regard, Figure 5 illustrates the placement of the ICP 510 implant (eg, the primary implant) along with sub-implants (ie, the screws) to secure the femoral neck fracture. As shown, the ICP 510 is attached to the femur 520 and screws are inserted through the neck and head of the ICP. The screws that enter the femoral head are located entirely within the head. In a further aspect of the present invention, since the
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ICP is contoured relative to the shape of the femur, the degrees of freedom in placing the ICP on the bone are limited and are used as part of the S402 alignment procedure. Specifically, the ICP can only travel along (ie, translation) and / or can rotate about the axis of the femur. Additionally, the ICP has tapped holes so that the position / angle of the screws relative to the plate is known.
Prior to insertion of the main implant within the region of interest, the main implant 510 is connected to a reference body or object. The reference body is preferably attached to (or part of) the implant, but can also be attached to an aiming device or instrument (eg, a drill guide). In this way, the position of the implant can be determined based on the location and position of the reference body. Preferably, each implant is associated with a different reference body that can be detected by system 100, in particular fluoroscope 110. In a preferred embodiment, the reference body comprises a plurality of spherical fiducial markers inserted on or in the instrument (by example, aiming device). By arranging fiducial markers in a certain pattern, they can serve as identifiers for different instruments. In this regard, the fiducial markers and the instrument may conveniently be referred to as a reference body, although the fiducial markers provide the reference.
For example, Figure 6A illustrates a side view of a reference body 604 as part of the implant 610. Together, the reference body and the implant are referred to herein as an implant system 614. As shown in the figure 6A, reference body 604 includes one or more fiducial markers 616 that are detected by the imaging system and used as reference or measurement points. Preferably, the fiducial markers comprise spheres to facilitate detection in a two-dimensional imaging system, such as a fluoroscope. Furthermore, the arrangement of the fiducial markers within the reference body functions as a signature that is used to identify the reference body and the associated implant. Since the dimensions of the reference body and the implant are known and these devices are fixed together, the location of the implant can be accurately determined by detecting or recording the location of the reference body. As also shown in Figure 6A, the fiducial markers can also be placed on the implant itself, but not necessarily.
Figure 6B is a perspective view of the aiming device 604 and implant 610 (which in keeping with the example is an ICP) in a separate condition. Figure 6C shows these two devices in a joined condition. As shown, the aiming device 604 is contoured to fit the ICP 610. In addition, it includes openings that allow access to the screw holes in the ICP 610 that are used to secure the implant 610 as explained in more detail below. To allow processing, the reference body must be in the field of view of the image with the implant and the region of interest 640, which consistent with this illustrative example includes the neck of the femur and the femoral head. As part of this initial insertion and placement, the surgeon will typically use a tactile feedback to determine a starting cubing for the implant.
Figure 7 shows an instrument 700 that can be used in the insertion and initial placement of ICP 610 onto a femur 720. In addition, in making this initial placement, the surgeon may use instrument 700 or reference body 604. To this In this regard, instrument 700 may also comprise a reference body by placing appropriate fiducial markers on or in it.
Referring to Figure 4B, once the surgeon determines an initial location for the implant (and the attached reference body), a fluoro-shot is taken from a region of interest along a first dimension or direction, at step 434. For example, a fluoroshot can be taken along the anteroposterior dimension or the axial dimension. Referring to Figure 1, the anteroposterior view is illustrated with the source 190 and detector 192 aligned along the y axis, while in the axial view the source and detector are aligned along the z axis. As shown in Figure 8, the fluoroshots can be taken from any two different dimensions or directions 810A, 810B. Preferably, the two images will be taken perpendicular to each other (that is, almost at a 90 degree angle to each other), but this is not necessary and any angle will suffice.
Because the implant and the reference body are located within the field of view of the imaging device, given their proximity to the region of interest, the fluoroscope 110 detects the presence of the reference body, ie, the fiducial markers. The computer 120 then uses the image data it receives from the fluoroscope 110 to provide a visualization of the implant location relative to the region of interest. In particular, the registration of fluoroscopic images is performed using the reference body. As discussed above, the reference body is typically in a fixed position relative to the implant and the bone. In addition, a disk is used in the image intensifier to develop the X-ray image. The disk is usually attached directly to the image intensifier. Such a reference body will also be seen in each image, and can be used to compensate for image distortion and for determining the center of, for example, the X-ray beam. Determining the implant with respect to the region The anatomy of interest is done using known image processing techniques based on the variation in spatial radiation reaching the detector, including radiation directed at the region of interest and the reference body.
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Using spatial variation, the computer is able to construct an image that accurately represents the spatial relationship between the implant and the region of interest (eg, the femur and the femoral head) as a two-dimensional image.
After viewing this image, the surgeon can then determine if the implant should be repositioned, as in step S438. For example, the surgeon may decide to adjust the position along the length of the femur closer to the femoral head or another degree of freedom. If the surgeon decides that such a fit is warranted, he places the implant as shown in step S440 and more fluoroshots are taken in step S434. On the other hand, if the surgeon determines that adjustment along this dimension is not necessary, the procedure continues at step S442 with stabilization of the implant. According to the example, stabilization can be accomplished by inserting a Kirshner wire (K-wire) through one or more openings in the ICP.
With the implant attached as described above, a fluoroshot can then be taken along a different dimension, step S446. In particular, if the fluoroshots in step S434 were taken along the anteroposterior direction, in step S446 they can be taken along the axial direction or at another angle. In this regard, as part of step S402, it may be sufficient to use a single image at this stage to optimize the position along only one degree of freedom (for example, a distal displacement of the implant) where the information is not required. 3D.
After the completion of the fluoride shot in step S446, the surgeon can then view an image of the implant position. If it is determined that the implant is to be adjusted in step S448, eg, rotated in the case of ICP, the procedure returns to step S446 and additional fluoroshoots are taken along this dimension. Once the surgeon is satisfied that the implant is properly positioned based on images obtained along this dimension, the procedure continues at step S450 with further stabilization of the implant. For example, when the implant or medical device is an ICP, K-needles can be inserted through additional openings in the ICP. As a result of the above procedure, the position of the ICP or other implant can be placed by the surgeon iteratively and in accordance with normal operating room workflow procedures. That is, the surgeon can repeat any stage of the procedure until the implant is properly placed.
With the implant positioned as described above in relation to step S402, the procedure then continues as shown in step S408 of Figure 4A and as will now be described in more detail as shown in Figure 4C. In particular, in step S454, the system can then generate 3D information from the two-dimensional fluoroshots recorded in step S402, or two additional two-dimensional fluoroshots can be taken at different angles as described above. Since the implant is now stabilized with respect to the region of interest, additional fluoro shots can be taken with the K needles acting as a trigger for the system. Furthermore, since the reference body can also be attached to the implant, it can also serve as a reference object as described above.
In accordance with this aspect of the present invention, the resulting 2D images are processed to locate and delineate a three-dimensional outline, ie, a sphere, of the femoral head. For example, Figure 9 shows an AP view image 910 and an axial view image 920 with overlapping circles 930, 940 outlining the contours of the femoral head. Circles 930, 940 can be constructed by computer 120 using image processing techniques, such as edge detection or computer generated patterns. Such models can be created preoperatively using MRI or other non-invasive techniques that can determine the location and size of organs or bones in the region of interest.
Furthermore, using the 2D images, then the computer 120 determines and generates a 3D object that is related to and models the region of interest, step S456, in accordance with another aspect of the present invention. In particular, Figure 10 illustrates the visualization of a virtual 3D sphere representing the head of the femur based on conical projections of 2D images 910, 920. As shown in Figure 10, the virtual 3D sphere is formed by the projection of the two-dimensional coordinate system onto a three-dimensional coordinate system. In this example, since the contour of the femoral head forms a circle, projection onto a three-dimensional coordinate system results in a sphere. Depending on the contours of the region of interest, these projections can be made using a Cartesian and / or spherical coordinate system. Furthermore, the location of the object with respect to the region of interest can be accurately determined based on the position of the implant in relation to the reference body.
Figure 11 shows the step of showing a visualization of the region of interest, implants and sub-implants based on a correspondence of the 3D sphere with the 2D images, step S458. As shown in FIG. 11A, the invention superimposes a virtual ICP 1104 with screws and a spherical contour of the femoral head on the original 2D axial image and the AP image. Visualization allows the surgeon to easily see the position of the ICP and screw it in relative to the femoral head. In particular, the visualization shows the position of the virtual screws, their length and how they will be placed in the femoral head. Also, the system may suggest the screw, for
ES 2 397 807 T3 example, a particular model, or the length of the screw that will be adequate to fix the implant.
Visualization also allows the surgeon to manually adjust the position of the actual ICP if better alignment is deemed necessary. For example, Figure 12A shows a proposed adjustment of ICP 510 in the distal direction, as seen from the two-dimensional AP image. More specifically, as can also be seen from Figure 12B, the display may also include areas that indicate the preferred translational fit of the implant relative to its current position. For example, an acceptance zone 1220 may be used (eg, using colors) to indicate a more preferable location. Therefore, if the screws are located outside of this area distally, the surgeon can manually adjust the sole at S55 and see an updated display by returning to step S52.
Figures 13A and 13B show how adjustment of ICP 610 can be achieved by external rotation 1300. In particular, analogous to translational adjustment, if the surgeon believes that the implant is not correctly aligned, they can adjust arrows 1300 to visualize how the implant will align if it is rotated. As can be seen from Figure 13B, an acceptance zone 1340 can be used to show how the rotation will change the location of the rings from a preferred position. As also shown in Figure 13B, the rotational movement is preferably performed after the location along the neck of the femur has been satisfactorily determined. Thus, the reference body 604 can be attached to the bone using a pin 1326. This pin 1326 can then be used with the toothed gear mechanism 1330 to more precisely rotate the implant as shown.
The system reacts to the surgeon rather than requiring the surgeon to act or interact with the computer or the system. Thus, if the surgeon decides that the implant is aligned correctly, he may then decide to secure the implant and complete the procedure. This minimizes disruptions to the current OR workflow and allows the surgeon to use judgment as part of the workflow. Rather, conventional approaches tend to disrupt OR workflow requiring the surgeon to interact with the CAS. This typically lengthens the surgical procedure and requires more equipment, both increasing the cost of surgical procedures.
After completion of the steps described above in relation to step S408, the procedure continues at step S424, where the implant can be attached to the region of interest. Additional fluoro shots can be taken during or after step S424 to verify the reduction of the fracture and the position of the ICP and K wires or screws. For example, Figure 15 shows the insertion of K needles 1620, 1630 and a detected movement of the femoral head 1610. Ideally, the system will detect such movement and propose corrective action, such as new screw lengths. If necessary, further implant repositioning and fracture reduction can be performed as discussed above.
As discussed above, Kirshner wires (K-wires) can be inserted through openings in reference body 604. More specifically, as shown in Figure 15, a first K-wire (1630) can be inserted. to fix the plate to the bone. (A second 1620 K needle can also be inserted through the fracture.) Then screws can be inserted to compress the fraction (S424). Screws can be self-tapping or can be inserted through drilled holes. The invention preferably includes image processing software that relies on edge detection to detect any insertion and curvature of the K screws or needles. Such software may comprise a component or routine in a set of instructions that performs the procedure. described above. The ICP has threaded screw holes so that the screw position / angle relative to the plate is fixed. K-wires can be removed before or after the screws have been inserted.
Alternatively, a scale aiming apparatus in combination with an oblong shaped hole (into which a K-wire can be inserted) can be attached directly to the ICP and used to facilitate mounting and any additional adjustments deemed necessary by the ICP. surgeon. Figure 14 shows repositioning using a prior art one-step apparatus 1400; which is preferably replaced by reference body 604 and other fasteners 1326, 1330 discussed above.
Turning now to Figures 16A-16H, an alternate use of the procedures described above is shown. As will be discussed in more detail, these figures show the insertion of a 1654 Fixation Nail, which is used as part of a hip fracture repair system. In particular, and with reference to FIG. 16A, the procedure begins with the insertion of nail 1654 into femur 1658. As also shown, nail 1654 is attached to a targeting instrument or device 1660. The targeting device is preferably equipped with a plurality of fiducial markers, eg, four or more, that act as a detectable reference body. by the imaging system. In accordance with the procedures described above, in this initial stage of the procedure, the surgeon obtains fluoroshoots along a first dimension. For example, a fluoroshot can be obtained along the patient's anteroposterior axis or at any other angle the surgeon deems appropriate.
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As shown in Figure 16B, if the shot is taken along the anteroposterior direction, the computer 120 detects and calculates the position of the reference body and instrument 1660, and displays a virtual nail 1666 in relation to the region of Interest 1670. In addition, the screen includes a projection 1674 of the location of a screw that will be used to secure nail 1654 in the femoral head or region of interest 1670. As also depicted in FIG. 16B, if the projected screw path 1674 is determined by the surgeon to require any adjustment, the surgeon may make a translational adjustment 1678 of the nail in the femur 1658. After the translational adjustment 1678 is made, the The surgeon then preferably takes one more additional fluoro shot to confirm that the fit has moved the nail 1654 to a more desirable position using screen 1680 similar to the one shown.
Once the surgeon is satisfied with the translational alignment of nail 1654, they can then use the system to rotatably align the nail as shown in Figure 16C. In particular, the surgeon will take a fluoroshot at a different angle, such as along a lateral direction of the hip to obtain image 1684 shown in FIG. 16C. Using this image, the surgeon can rotate nail 1654 to a more desirable position and take more fluoroshots to confirm the fit.
Once the surgeon determines that nail 1654 is properly aligned, they can then insert a 1687 K needle as shown in Figure 16D. With the K-needle inserted, two or more two-dimensional images can be obtained with the fluoroscope, as described above. Using these two or more images, the system is then able to determine the appropriate nail lengths, as shown in Figure 16E. In particular, two-dimensional images are used to create an object that models the region of interest, in this case, the femoral head. More specifically, when the region of interest is the femoral head, computer 120 uses these two two-dimensional images to create a 1689 sphere and superimposes on the sphere the location and length of screws that can be used to fix nail 1654. As shown in Figure 16E, the screen shows a virtual screw 1691 along with graduation marks 1693 indicating the length of the screw just inside the ball 1689 and out through an opening in the nail 1654.
Based on the graduation marks 1693 shown in Figure 16E, the surgeon can then select an appropriate screw of a desirable length to fix the nail 1654. Once the screw is selected, it is then inserted as shown in Figures 16F. and 16G. As also described above, once the screw is in place, additional images can be taken to verify that the length of the screw secures the device without protruding from the region of interest as a result of the forces that were applied during the procedure. fixation, as illustrated in Figure 16H.
The image processing performed by the invention includes: detection and segmentation of an anatomical abnormality; detection of the position of the reference body; generation of 3D information from 2D images; registration, conversion and visualization of 3D information in 2D images; and calculation of the optical position of the implant. Furthermore, in another aspect, the system can propose an appropriate length for each screw.
As discussed above, they require at least two 2D images containing the reference body by the invention to provide 3D information. These pictures should be taken at different angles (preferably a near 90 degree angle). Additional 2D images can also be used to provide information. The images can be registered with each other by detecting distinctive anatomical abnormalities in the images and / or using the reference body. The reference body (which appears in each image) can be used to accurately record images in three dimensions. The reference body can also be useful in automatically detecting these anatomical structures for segmentation (for example, by detecting the edges of abnormalities). The relative position of specific anatomical structures with respect to the reference body position can also be calculated based on general statistics of bone shape and patient data (eg size, gender, age). This relative position can be used as a starting point for segmentation algorithms. Once the anatomical structures have been segmented, the image processing software can correlate the structures of different images to generate 3D information.
Various three-dimensional reconstruction algorithms can be used to generate this information. Typically, algorithms will approximate segmented anatomical abnormalities with geometric shapes (eg, a circle). The geometric shapes are then matched / recorded with respect to their known relative positions in the 2D images. These shapes are then projected into 3D space to form, for example, a sphere or a cylinder. The invention can initially select a typical 3D shape for an anatomical region from a database and match it to the image by zooming, rotating and / or translating the shape. The shape can also be altered, such as with a shaping algorithm, for better matching. In fact, preoperative images can be taken of the same anatomical region to better determine the true shape of various abnormalities.
ES 2 397 807 T3
Since the reference body is located in each image and is attached to an anatomical region (eg, a bone), movement of the patient during surgery is not a problem. This is because the system can use the location of the reference body to record different fluoroscopic images (regardless of image content) and generate a true 3D image of few artifacts using 3D reconstruction algorithms. This aspect of the invention for accurately registering images reduces artifacts due to patient movement during surgery. Preoperative planning can be done by taking preoperative images similar to intraoperative images. This preoperative planning can be used to determine optimal sub-implant placement which can then be checked against intraoperative placement. Such preoperative images can be processed using different algorithms that are too slow to be used during surgery or they can be segmented and matched manually.
As discussed above, the invention can also provide a reactive workflow by automatically detecting the status of an operation and thus knowing the next operational steps to be performed. In this way, the invention can provide suggestions to the surgeon. For example, the invention may suggest a specific type, size, or shape of a Best-fit implant based on the detected geometry of a fracture. Furthermore, the invention can modify a previous suggestion based on additional information determined during surgery.
The stereotactic device can be implanted in the body. Furthermore, the invention uses 2D images (eg, fluoroscopic X-rays) to generate 3D information. The reference plate (ICP) is contoured to match the superficial contour of the bone by limiting the degrees of freedom for adjustments. The reference plate (ICP) is also threaded so the relative position of the screw is known. The invention calculates and proposes the position of the reference plate, the position of the sphere, the position of the screw and the lengths.
Advantages of the invention include that it reduces surgical time for implant insertion, requires little interaction between the surgeon and the system, provides three-dimensional information about important regions, requires few changes to operating room procedures, and is more economical than current tracking-based navigation. Additional features of the invention include that it takes into account any curvature of the Kirshner wires (K wires) through automatic detection, calculates and displays any dislocation of the femoral head during implantation, and calculates the lengths of the femur. screws. Although the invention has been described herein with reference to an ICP procedure, it is understood that this embodiment is merely illustrative of the principles and applications of the present invention.
Contents8
29 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12 Sheet 13 Sheet 14 Sheet 15 Sheet 16 Sheet 17 Sheet 18 Sheet 19 Sheet 20 Sheet 21 Sheet 22 Sheet 23 Sheet 24 Sheet 25 Sheet 26 Sheet 27 Sheet 28 Sheet 29
17 members in 4 offices
Priority claims9
| Document | Office | Kind | Date |
|---|---|---|---|
| 10543P | United States of America | – | |
| 1054308 | United States of America | P | |
| 1054308 | United States of America | P | |
| 2009050210 | European Patent Office (EPO) | W | |
| 2009050210 | European Patent Office (EPO) | W | |
| 10543P | – | – | – |
| PCTEP2009050210 | – | – | – |
| US20080010543P | – | – | – |
| WO2009EP50210 | – | – | – |
Members17
| Document | Office | Kind | |
|---|---|---|---|
| WO2009087214A1 | World Intellectual Property Organization (WIPO) | A1 | |
| US2009209851A1 | United States of America | A1 | |
| WO2009087214A4 | World Intellectual Property Organization (WIPO) | A4 | |
| EP2173269A1 | European Patent Office (EPO) | A1 | |
| EP2191783A1 | European Patent Office (EPO) | A1 | |
| US2011019884A1 | United States of America | A1 | |
| EP2191783A9 | European Patent Office (EPO) | A9 | |
| EP2173269B1 | European Patent Office (EPO) | B1 | |
| ES2397807T3This record | Spain | T3 | |
| EP2191783B1 | European Patent Office (EPO) | B1 | |
| ES2595366T3 | Spain | T3 | |
| US10070903B2 | United States of America | B2 | |
| US10105168B2 | United States of America | B2 | |
| US2018325566A1 | United States of America | A1 | |
| US11642155B2 | United States of America | B2 | |
| US2023218323A1 | United States of America | A1 | |
| US2025221747A1 | United States of America | A1 |
Numbers
- Publication
- 2397807
- Publication, DOCDB
- 2397807
- Publication, EPODOC
- ES2397807T
- Application
- 9700962
- Application, DOCDB
- 09700962
- Application, EPODOC
- ES20090700962T
Titles2
- Spanish
- Cirugía estereotáctica asistida por ordenador en base a visualización tridimensional
- English
- Computer-assisted stereotactic surgery based on three-dimensional visualization
Classification
- CPC, 16
- A61B17/744
- A61B17/1703
- A61B17/1721
- A61B17/1725
- A61B17/1728
- A61B17/746
- A61B2090/363
- A61B2090/367
- A61B34/20
- A61B34/25
- A61B2090/376
- A61B2034/107
- A61B90/37
- A61B90/11
- A61B17/1753
- A61B2017/564
- IPC, 4
- A61B19 00
- A61B17 17
- A61B17 76
- A61B17 78