Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/10—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges for stereotaxic surgery, e.g. frame-based stereotaxis
  • A61B90/11—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges for stereotaxic surgery, e.g. frame-based stereotaxis with guides for needles or instruments, e.g. arcuate slides or ball joints
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T7/00—Image analysis
  • G06T7/70—Determining position or orientation of objects or cameras
  • G06T7/73—Determining position or orientation of objects or cameras using feature-based methods
  • G06T7/75—Determining position or orientation of objects or cameras using feature-based methods involving models
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
  • A61B2034/101—Computer-aided simulation of surgical operations
  • A61B2034/105—Modelling of the patient, e.g. for ligaments or bones
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/36—Image-producing devices or illumination devices not otherwise provided for
  • A61B2090/364—Correlation of different images or relation of image positions in respect to the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
  • A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/10—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges for stereotaxic surgery, e.g. frame-based stereotaxis
  • A61B90/14—Fixators for body parts, e.g. skull clamps; Constructional details of fixators, e.g. pins
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/36—Image-producing devices or illumination devices not otherwise provided for
  • A61B90/361—Image-producing devices, e.g. surgical cameras
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N2/00—Magnetotherapy
  • A61N2/004—Magnetotherapy specially adapted for a specific therapy
  • A61N2/006—Magnetotherapy specially adapted for a specific therapy for magnetic stimulation of nerve tissue
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/10—Image acquisition modality
  • G06T2207/10072—Tomographic images
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/30—Subject of image; Context of image processing
  • G06T2207/30004—Biomedical image processing
  • G06T2207/30016—Brain
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/30—Subject of image; Context of image processing
  • G06T2207/30004—Biomedical image processing
  • G06T2207/30052—Implant; Prosthesis

Definitions

• the present invention relates to a system for assisting the positioning of a medical tool on the head of a subject and a positioning aid method associated therewith.
• the subject is a topic of analysis or a patient.
• Transcranial magnetic stimulation is a technique of cortical stimulation, the principle of which is based on the generation of a high intensity focused magnetic field. This technique stimulates a target neuroanatomical area painlessly and non-invasively.
• the stimulation is carried out by means of a coil in which a strong electric current circulates which induces the generation of a focused magnetic field. Because of the focal nature, the applications in neurology and psychiatry are numerous, for example the treatment of depression ...
• Neuronavigation allows a geometrical matching of the real anatomy of the subject with his anatomy represented via an imaging modality, preferably magnetic resonance imaging (MRI) type.
• an imaging modality preferably magnetic resonance imaging (MRI) type.
• MRI magnetic resonance imaging
• the document WO 2010/084262 describes a device making it possible to automatically match the patient's head with images of the patient acquired by MRI by means of a registration algorithm which, from anatomical correspondence points. between the patient's head and the MRI images, manages to calculate the transformation of the three-dimensional mark of the patient to the reference frame of the MRI images.
• the object of the invention is to propose a system for assisting the positioning of a medical tool on the head of a subject making it possible to dispense with the images acquired by MRI while ensuring a reliable positioning of the medical tool.
• the subject of the invention is a system for assisting the positioning of a medical tool of the aforementioned type, characterized in that it comprises means for predicting the location of a target intracranial zone of the tool.
• medical device comprising:
• a generic three-dimensional model of a head comprising a skin and a generic target intracranial zone
• surface registration means adapted to establish a registration transformation of the skin of the generic model to the working image of the skin of the head of the subject
• the positioning aid system comprises one or more of the following characteristics taken alone or in combination:
• the three-dimensional work image of the skin of the subject's head is an X-ray image
• the three-dimensional working image of the skin of the subject's head is a surface image acquired by a three-dimensional localization system
• the medical tool is a coil of an intracranial magnetic stimulation device
• DLPFC dorsolateral prefrontal cortex
• the invention also relates to a method of assisting the positioning of a medical tool on the head of a subject, characterized in that it comprises the following steps:
• the positioning aid method is devoid of a step of acquiring images of at least the head of the subject by magnetic resonance imaging.
• FIG. 1 is a schematic view of a system for assisting the positioning of a medical tool on the head of a subject according to the invention
• FIG. 2 is a block diagram illustrating the method implemented by the positioning aid system of FIG. 1.
• this neuroanatomical zone corresponds to the interface between areas 9 and 46 of Brodmann's cytoarchitectonic atlas.
• the invention is in no way limited to this zone but applies to any cerebral area.
• the aid system 10 illustrated in Figure 1 is intended to position a medical tool 12 on the head of a subject 14.
• the subject 14 is a subject of analysis, for example an individual suffering from depressions, obsessive-compulsive disorders , neuropathic pain or auditory hallucinations in schizophrenia requiring transcranial magnetic stimulation of the dorsolateral prefrontal cortex of the brain.
• the medical tool 12 is preferably an electromagnetic stimulation device, such as transcranial magnetic stimulation, comprising a stimulation coil 16, in which a strong electric current circulates which induces the generation of a magnetic field focused on the cortical target to reach: the DLPFC.
• an electromagnetic stimulation device such as transcranial magnetic stimulation
• a stimulation coil 16 in which a strong electric current circulates which induces the generation of a magnetic field focused on the cortical target to reach: the DLPFC.
• the aid system 10 includes a neuronavigation device 18, i.e., an image guidance device, and a positioning system 20, in three parts. dimensions, in order to follow in real time the position of the point stimulated by the stimulation coil 16 and to compare it with the desired position of stimulation.
• a neuronavigation device 18 i.e., an image guidance device
• a positioning system 20 in three parts. dimensions, in order to follow in real time the position of the point stimulated by the stimulation coil 16 and to compare it with the desired position of stimulation.
• the positioning system 20 comprises a positioning tool 22, such as a strip 24 fixed around the head of the analysis subject 14, and a camera 26 in direct or indirect relation with the positioning tool 22.
• the camera 26 is for example a binocular camera.
• the strip 24 is marked and adapted to be recognized by the camera 26 and thus defines a frame attached fixedly to the head of the subject 14.
• the help system 10 includes a computing device 40 having a first memory 42 capable of storing data such as for example a RAM type memory for "Random Access Memory” in English.
• This first memory 42 is arranged to store a generic three-dimensional cartography of at least part of the head of a model and comprising at least the model brain, also called atlas.
• the brain referred to at this stage is a brain that can be described as a model brain or a generic brain. For example, it is a digitized MRI atlas of a model brain.
• Generic three-dimensional mapping includes the location of the target area, here the dorsolateral prefrontal cortex (DLPFC) and the skin of the model head with the model brain.
• DLPFC dorsolateral prefrontal cortex
• the first memory 42 also stores precise designation data of the target area: the DLPFC.
• the computing device 40 includes a second memory 44 capable of storing data, for example of the RAM type.
• the second memory 44 is arranged to receive and store a working image of at least a portion of the head of the analysis subject.
• the working image is a three-dimensional surface image of the skin of the subject's head. It is obtained either by a method of medical imaging other than magnetic resonance imaging (MRI) or by a device for location / three-dimensional tracking (or "optical tracking" in English), for example the MICRONTRACKER device of the company CLARON TECHNOLOGY or POLARIS® device from Northern Digital Inc NDI).
• MRI magnetic resonance imaging
• POLARIS® device from Northern Digital Inc NDI
• Such a system includes a binocular camera that films the scene, a marked strip recognized by the camera and serving as a reference attached fixedly relative to the subject's head, a marked pointer recognized by the camera and a computer connected to the camera.
• the binocular camera and the strip of the three-dimensional localization device are, for example, those of the positioning system 20.
• the computing device 40 also comprises a surface resetting means 46 which receives generic three-dimensional mapping data and working data respectively from the first memory 42 and the second memory 44. It is from these data that the means of surface registration 46 establishes a registration transformation of the skin of the generic model to the working image of the skin of the subject's head.
• the computing device 40 also comprises a means of resampling 48 of the target generic intracranial zone into a target zone converted according to the registration transformation transmitted by the surface registration means 46.
• the resampling means 48 is adapted to transmit the data representative of the converted target zone to the neuronavigation device 18.
• the aid system 10 comprises a man-machine interface 30 connected to the neuronavigation device 18 and adapted to display visualization images transmitted by the neuronavigation device 18.
• the aid system 10 implements the steps of the method of assisting the positioning of a medical tool on the head of a subject illustrated in FIG. 2.
• a neuroanatomist locates a predefined target zone 104, for example the left CPFDL, as well as anatomical landmarks, which will then be used for resetting, on a digital MRI head atlas, ie means a generic three-dimensional mapping of at least part of the head and brain. This step is performed once for all stimulation sessions.
• the full-face digital MRI atlas is the MRI atlas described in the article by Lalys F, Haegelen C, Ferre JC, El-Ganaoui O, Jannin P., entitled "Construction and assessment of a 3-T MRI”. brain template "published in Neuroimage in August 2009.
• the surface 106 of the skin of the atlas is extracted during a step 108 via conventional segmentation techniques.
• the digital data corresponding to the surface 106 of the skin of the extracted atlas are stored in the first memory 42 of the computing device 40 of the help system 10.
• the surface 1 12 of the skin of the subject is extracted.
• the step 1 10 of extraction of the skin of the subject requires a step 1 16 of acquisition and reconstruction of the skin of the subject implemented by a three-dimensional location system.
• MRI magnetic resonance imaging
• CT X-ray CT
• the subject is installed in the field of view of the camera 26 of the three-dimensional location system.
• the strip 24 of this three-dimensional location system is fixed on the head of the subject and recognized by the camera 26.
• the strip then defines a frame attached fixedly relative to the head of the subject.
• An operator then uses a pointer of the three-dimensional location system also recognized by the camera 26 and thus makes it possible to sample the head of the subject with a cloud of points defined by the position of the pointer in the reference defined by the strip 24.
• the camera films the scene, that is to say the different positions of the pointer.
• the signals corresponding to the points are transmitted to the computing device 40 and are stored in a memory of the computing device 40. They are digitized in order to be processed by the computer device 40 to extract or reconstruct the surface 1 12 of the skin from this cloud of points.
• the recorded point cloud is pre-processed by smoothing, then outliers (or points) are excluded and normal to the curves defined by the point cloud are calculated.
• a Poisson algorithm allows to reconstruct a smooth and regular surface from scattered cloud of points.
• the surface 12 of the subject's skin or any other digital data representative thereof is then recorded in the second memory 44 of the computing device 40.
• the precision of the surface reconstruction of Poisson was validated from a phantom, for example a manikin, having been sampled by the method described above and an X-ray scanner. It was evaluated by carrying out a surface registration, via an algorithm of the closest point iterative algorithm type (ICP for "Iterative Closest Point"), from the point cloud to the surface of the skin extracted from the X-ray scanner and by applying the calculated transformation to the reconstructed Poisson surface from the point cloud.
• ICP closest point iterative algorithm type
• the method 100 continues with a step 1 18 of registration of the skin surface of the atlas and the surface of the skin of the subject. In fact, the skin surface of the atlas is deformed on the surface of the subject's skin.
• This step 18 of surface registration is performed by the surface resetting means 46 of the computer device 40 in several steps applied successively.
• the surface registration means 46 receives the generic three-dimensional mapping data, i.e., the skin surface of the model, and the working data, i.e., the surface of the skin of the subject, respectively of the first memory 42 and the second memory 44.
• the surface registration means 46 performs a step of initializing the registration from the anatomical landmarks located on the atlas by the neuroanatomist during step 102 and on the subject during step 1. extracting the skin of the subject either from images acquired by X-ray scanning, at 1 14, or from sampling of the skin of the subject at 1 16.
• the surface registration means 46 applies a rigid surface registration of the reconstruction of the skin extracted from the MRI atlas to the surface of the subject's skin via an ICP type algorithm.
• the surface registration means 46 performs a nonlinear surface registration of the reconstruction of the skin extracted from the MRI atlas to the surface of the subject's skin.
• a non-linear surface registration is described in the article by Benoît Combès and Sylvain Prima, entitled “An efficient EM-ICP algorithm for symmetric non-linear registration of points sets.” And presented during the 13 th international conference “Medical Image Computing and Computer-Assisted Intervention (MICCAI)" in September 2010.
• the correction transformation calculated during the surface registration step 18 is applied to the left CPFDL located by the neuroanatomist on the MRI atlas to have its position relative to the surface of the skin extracted. in step 1 10.
• the registration transformation comprises all the transformations calculated during the different registration steps described above.
• the coordinates of the left CPFDL are thus obtained in the anatomical reference frame of the subject represented by the reconstruction of the skin, which are transmitted to the neuronavigation device.
• the latter matches the real reference point in which the analysis subject evolves with the anatomical reference point of the subject (the surface of the skin).
• a visualization image is formed from visualization data transmitted by the neuronavigation device and which at least partially matches the working image and the converted cartography, while indicating, in the visualization image, a area that corresponds to the converted designation data.
• This visualization image is transmitted to the user interface 30 which displays it in order to be seen by the clinician or the operator.
• the left CPFDL is located in the patient in an automated manner without the particular intervention of a clinician.
• the operator positions a coil 16 for emitting electromagnetic pulses.
• This positioning of the coil of the TMS device is adjusted with respect to the visualization images presented on the user interface 30, via the positioning tool 22 and the camera 26.
• the cerebral localization aid system of the invention makes it possible to accurately follow, in real time, the zone effectively stimulated by the magnetic stimulations of the TMS thanks to to the neuronavigation device 18.
• a group B of analysis subjects without any other imaging modality than their magnetic resonance image (MRI).
• MRI magnetic resonance image
• the left CPFDL was first spotted by a neuroanatomist on each
• step 1 10 of reconstruction of the skin without imaging modality described above by means of a three-dimensional localization device For group B, according to step 1 10 of reconstruction of the skin without imaging modality described above by means of a three-dimensional localization device.
• DLPFC dorsolateral prefrontal cortex

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  • 2011-01-26 FR FR1150606A patent/FR2970638B1/fr not_active Expired - Fee Related
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