FR2895267A1 - Non-invasive navigation device for use during operation of implantation of knee prosthesis, has navigation system including unit analyzing bone representation to provide representation of axles of referred prosthesis implantation, on screen - Google Patents

Abstract

The device (100) has a fluoroscope (110) i.e. radiation emission radioscopy, providing images of a part i.e. knee joint, of a patient body, and a computer (120), processing the image from the fluoroscope that provides two dimensional bone representation of the joint. An interface is provided between the computer and a navigation system. The system has an analyzing unit that analyzes the bone representation to provide a referral of prosthesis to be implanted and a representation of main axles of referred implantation of the prosthesis in the body part, on a screen (145) e.g. touch screen.

Description

METHOD AND DEVICE FOR NON-INVASIVE NAVIGATION

  The present invention relates to a method and a non-invasive navigation device. It applies, in particular, to assistance to surgeons before or during a surgical operation. The present invention aims to be less invasive during a pre-operative investigation to provide the surgeon, in real time, an anatomical location of tools whose positioning conditions the success of the operation. To manage, by navigation, the installation of a prosthesis, for example knee, the operator needs to know the anatomical characteristics of the limb to operate, in particular: - the value of the frontal deformity, - the medial dimension Lateral, antero-posterior articulation, the angular value between the anatomical axis and the mechanical axis and a three-dimensional view of this articulation.

  Indeed, these elements are the basis of reflection of the operative protocol of the surgeon. The investigation aims to set up a disordered form to operate, for example the knee. To date, this investigation is performed after opening the joint to be operated, which involves many disadvantages such as the lengthening of the duration of the operation and the increase in operative risks, such as infections, for example.

  The present invention aims to allow an investigation that does not include opening of the joint. According to a first aspect, the present invention aims a non-invasive navigation device comprising: - a geometric database of prostheses, - a fluoroscope which provides a plurality of two-dimensional images of a part of the human body. an image processing means (computer) derived from the fluoroscope which provides a three-dimensional bone representation; an interface between the processing means and a navigation system which comprises a screen and a means for analyzing bone representation and geometric data of prostheses to provide: a prosthesis recommendation to be implanted; an on-screen representation of the main axes of the recommended implantation of said prosthesis in said part of the human body.

  Thanks to these provisions, the operator can choose a prosthesis and visualize the future implantation of said prosthesis, on an image.

  According to particular features, the device as briefly described above comprises; at least one positioning sensor providing, to a navigation system, tool positioning information on the actual bone of the patient; - The navigation system being adapted to represent on the screen, together, the main axes of the recommended implantation of the prosthesis and the main axes of the implantation of the prosthesis corresponding to the positioning of the tools provided by each positioning sensor. Thanks to these provisions, the operator can visualize the implantation of said prosthesis, on an image and, during the operation, see the difference between the recommended implantation and implantation that results from the handling of the tools. According to particular characteristics, the positioning sensor comprises an image transceiver. According to particular characteristics, said transceiver is of the infrared type. According to particular features, the navigation device as briefly described above comprises means for processing an image of a standardized spherical reference system positioned near the part to be operated in order to take measurements from dimensions of this reference frame. spherical.

  According to particular features, the device as briefly described above comprises a tool image processing means adapted to determine the position of tools used during an operating phase. According to particular features, the navigation device as briefly described above includes a memory of operating procedures and trajectories, the navigation system being adapted to represent, on the screen, jointly, a recommended trajectory of a tool and a real trajectory of a tool. Other advantages, aims and features of the present invention will emerge from the description which follows, made with an explanatory and in no way limiting purpose, with reference to the appended drawings, in which: FIG. 1 represents, schematically, a mode of particular embodiment of a non-invasive navigation device object of the present invention and - Figure 2 represents, in the form of a logic diagram, a succession of steps implemented for the use of the device illustrated in Figure 1. In any the description describes an embodiment of the device which is the subject of the present invention, adapted to an implantation operation of a knee prosthesis. However, the present invention is not limited to this type of operation and extends to the entire field of surgery.

  FIG. 1 shows a non-invasive navigation device 100 comprising a fluoroscope 110, a computer 120, a prosthesis database 125, an anatomical model database 130, a memory of operating procedures and trajectories 135, a video memory 140, a screen 145, an image transceiver 160, referred to by the generic term camera for simplification, a spherical frame 170, three reflectors 180, 181 and 182 and a control means 190. The fluoroscope 110 of known type is a radioscopy emitting of small radius. The fluoroscope 110 provides a plurality of images of a portion of the human body, for example, the knee joint and, in particular, enables a two-dimensional bone representation to be determined. It is the use of the reference sphere 170 and the shooting in three different places, for example lateral, front and three-quarter, which gives, by action of the computer 120, a three-dimensional image. In the embodiment described here, the fluoroscope 110 is provided with an arcuate arm whose ends emit and reflect low-radioactive rays. Generally, a third person manipulates this equipment and moves the arm in an arc to capture images of the area to be operated at different angles (face, profile and three quarters, for example). The triggering of the shooting is triggered by action on the control means 190 or, if it is tactile, on the screen 145, opposite an indication, menu or icon, representing the shooting.

  The computer 120 is of known type. It implements software implementing the steps described in the logic diagram illustrated in FIG. 2. The memory of the computer 120 stores the database of prostheses 125, the anatomical model database 130, the operating and trajectory procedures. and the video memory 140. The prosthesis database retains prosthetic dimensions of several sizes and characteristic geometric axes of these prostheses. The anatomical model database maintains, for the operating area, models of the different anatomies that can be found on patients. The database of operating procedures and trajectories 135 preserves the succession of steps that the practitioner must observe during an operation and the trajectories of the tools, for example of cutting, which correspond to these operating procedures. The spherical frame 170 is of known and standardized dimension. The spherical frame 170 is, for example, consisting of a sphere of diameter between 20 and 35 millimeters, made of metal, wood or plastic, for example. It is placed, and secured with an adhesive tape, against the site to be operated (the limb to be operated) in the field of view of the fluoroscope 110. The shooting by the fluoroscope 110 is performed frontally, in profile and three quarters for example, which provides the active data.

  The video memory 140 retains the images taken by the camera during each operation. The video memory 140 also retains the front, profile and three-quarter shots made by the fluoroscope 110. Each shot includes an image of the spherical frame 170.

  The screen 145 is of known type, for example of liquid crystal type, plasma and is preferential touch. It displays images from the computer 120, the fluoroscope 110 and the camera 160. The camera 160 is preferably adapted to capture images in the infrared spectral range. For this purpose, it comprises an infrared transmitter 165, for example consisting of an infrared light emitting diode. The reflectors 180, 181 and 182, also called position sensors in the following description, send the radiation from the infrared transmitter 165 of the camera 160 to the camera 160 so that it allows the identification of the elements of the camera. joint to operate, which move during a surgical procedure. The reflectors are, for example, retro-reflector type. These reflectors 180, 181 and 182 are of two types: passive, reflectors 181 and 182, which are fixed on the member to be operated shown in FIG. 1 by a circle and - active, reflector 180, movable with a piece of surgical material which guides the surgical gesture. During its operation, the computer 120 performs a treatment of the images from the fluoroscope 110 to obtain a three-dimensional bone representation of the knee joint of the patient. The computer 120 approximates the shots kept in the video memory 140, the spherical frame 170 which provides a scale and the three-dimensional modeling of the type of articulation preserved in the anatomical model database 130. computer 120 provides the anatomical features of the limb to be operated, in particular: - the value of the frontal deformity, - the medio-lateral, anteroposterior dimension of the joint, - the angular value between the anatomical axis and the mechanical axis and - a three-dimensional view of this articulation. The computer 120 also performs a bone representation analysis to provide: a prosthesis recommendation to implant and an on-screen representation of the main axes of the recommended implantation of said prosthesis in said part of the human body.

  By implementing menus in a portion of the screen 145, the operator or the surgeon can accept or reject the proposed menu options. The computer 120 represents, on the screen 145, jointly, the main axes of the recommended implantation of the proposed prosthesis, then of the prosthesis chosen by the practitioner, and the main axes of the implantation of the prosthesis corresponding to the positioning. of each tool provided by each positioning sensor. The computer 120 implements navigation and parameterization software, - the three-dimensional modeling of the standard joint to be operated (matrix), - the geometric and dimensional characteristics of the prosthesis to be implanted (spreadsheet). The calculation program reconciles the reference database with the active data. The image obtained is a deformation of the matrix and corresponds to the three-dimensional articulation of the patient. By comparing with the spreadsheet, the program defines the size and shape of the implant most appropriate to the joint to be operated. Under the guidance of the navigation software, data of the current art, the operating protocol can begin with a control and a permanent record of the successive operating phases, a joint display, on the screen, of the main axes of the recommended implementation of the prosthesis and the main axes of the implantation of the prosthesis corresponding to the positioning of each tool provided by each positioning sensor. From the memory of operating procedures and trajectories 135, the navigation system also represents, on the screen, jointly, a recommended trajectory of a tool and a real trajectory of a tool.

  During a step 205, the surgeon, or the assistant operator, positions the fluoroscope 110 and the spherical reference frame 170 opposite the joint to be operated and connects the various electrical and electronic components to each other and to a power supply. . From the beginning of a step 210, the fluoroscope 110 permanently provides an animated image of the joint to be operated, according to at least two angles of view. Under the control of the operator, through the screen 145 and the control means 190, images taken by the fluoroscope 110 are put in video memory 140. The images provided by the fluoroscope 110 comprise at least four shots according to four different orientation, face, profile three quarters straight, three quarters left. They are optionally compressed by the computer 120 before being stored.

  During a step 215, the computer 120 determines, on the basis of the images transmitted by the fluoroscope 110, a three-dimensional bone representation, according to known techniques. During a step 220, the computer 120 processes the images from the fluoroscope 110 to determine the apparent diameter of the spherical reference frame 170. During a step 225, the computer 120 compares the apparent diameter and the actual diameter, otherwise known, for example by keyboard input, of the spherical frame 170, to determine scale or magnification factors to be applied to the measurements made with the fluoroscope 110 and the camera 160. In a step 230, the computer 120 makes the connection between the database of anatomical models, the matrices, that is to say the three-dimensional modeling of the standard joint to be operated, and the active data to determine the deformation of the matrix kept in a database that best corresponds to the patient's three-dimensional articulation. The operator can thus view, on the screen 145, what gives the computer in terms of dimensions and deformations. The computer 120 thus provides the anatomical characteristics of each limb to be operated, in particular: the value of the frontal deformity, the medio-lateral, anteroposterior dimension of the joint, the angular value between the anatomical axis and the mechanical axis and - a three-dimensional view of this articulation. During a step 235, by approximation with the spreadsheet of each prosthesis represented in the prosthesis database 125, the computer 120 defines the size and shape of the implant most appropriate to the joint to be operated. The operator can then choose the prosthesis and simulate its implantation on the actual joint to operate. In a step 240, the computer 120 represents, in each displayed image from the fluoroscope 110 or the camera 160, the implant selected as it should be implanted, respecting the scale factors. The axes of the implant and bones linked to the joint are also represented on these images. During a step 245, the surgeon decides whether or not to accept the proposed implant, step 245 and, if he refuses, he chooses an implant by visualizing the implants represented in the prosthesis database 125 , step 250. The operation 240 is then repeated until the surgeon validates the choice of an implant. The computer 120 thus performs a bone representation analysis to provide: a prosthesis recommendation to implant and an on-screen representation of the main axes of the recommended implantation of said prosthesis in said part of the human body.

  The computer 120 also represents, on the screen 145, jointly, the main axes of the recommended implantation of the proposed prosthesis, then the prosthesis chosen by the practitioner.

  The fluoroscope is then decommissioned. During a step 255, the operator positions the passive reflectors 181 and 182 on the joint to be operated. The surgeon validates the correct positioning of the joint to be operated, by means of the display of the reflectors 181 and 182 with the camera 160 and the screen 145. The operating protocol, related to the selected prosthesis, is then displayed, stage by step, on the screen 145. In the course of step 255, under the guidance of the navigation software, the operating protocol begins with a control and a permanent recording of the video images of the successive operating phases.

  The surgeon then visualizes the various operations on the screen 145 to the virtual positioning of the virtual prosthesis (or modeled) in the model of the considered joint. The surgeon also visualizes the deformation of the joint that will result from the implantation of the chosen virtual prosthesis. Then the surgeon starts performing the actual operative procedure.

  By locating the active reflector 180, in a step 260, the computer 120 processes the images provided by the camera 160 to determine the position of the tools used by the surgeon. During a step 265, the computer 120 determines the main axes of the implantation of the prosthesis corresponding to the positioning of each tool.

  During a step 270, the computer 120 jointly displays, on the screen 145, the main axes of the recommended implantation of the prosthesis and the main axes of the implantation of the prosthesis corresponding to the positioning of each tool provided. by each positioning sensor. During a step 275, from the memory of operating procedures and trajectories 135, which preserves the succession of steps that the practitioner must observe during the operation and the trajectories of the tools that correspond to these operating procedures , the navigation system also represents, on the screen, jointly, the recommended trajectory of each tool and the actual trajectory of the tool. The surgeon performs the sequence of operations of the operating procedure to have positioned the prosthesis, viewing, on the screen 145, the corrected articulation.

Claims (1)

  1 - non-invasive navigation device, characterized in that it comprises: - a geometric database of prostheses 125, - a fluoroscope 110 which provides a plurality of images of a part of the human body; a means for processing an image of a standardized spherical reference frame positioned near the part to be operated in order to take measurements from dimensions of the spherical reference frame. a means for processing the images from the fluoroscope which provides a two-dimensional representation of the bone; an interface between the processing means and a navigation system that includes a screen and bone representation analysis means for providing: a prosthesis recommendation to be implanted; an on-screen representation of the main axes of the recommended implantation of said prosthesis in said part of the human body; 2 - Device according to claim 1, characterized in that it comprises: - at least one positioning sensor providing, to a navigation system, tool positioning information on the actual bone of the patient; - The navigation system being adapted to represent on the screen, together, the main axes of the recommended implantation of the prosthesis and the main axes of the implantation of the prosthesis corresponding to the positioning of each tool provided by each positioning sensor . 3 - Device according to claim 2, characterized in that the positioning sensor comprises a camera. 4 - Device according to claim 3, characterized in that said camera is an infrared camera. 5 - Device according to any one of claims 3 or 4, characterized in that it comprises a tool image processing means adapted to determine the position of tools used during an operating phase. 6 -Dispositif according to any one of claims 1 to 5, characterized in that it comprises a memory of operating procedures and trajectories, the navigation system being adapted to represent, on the screen, jointly, a recommended trajectory d a tool and a real trajectory of a tool.