Publications of Alexandre Bilger

Publications HAL de bilger de la structure shacra;mimesis

2015

Conference papers

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titre
Anticipation of Brain Shift in Deep Brain Stimulation Automatic Planning
auteur
Noura Hamzé, Alexandre Bilger, Christian Duriez, Stéphane Cotin, Caroline Essert
article
IEEE Engineering in Medicine and Biology Society (EMBC’15), Aug 2015, Milan, Italy. IEEE, pp.3635 – 3638 2015, <10.1109/EMBC.2015.7319180>
resume
Deep Brain Stimulation is a neurosurgery procedure consisting in implanting an electrode in a deep structure of the brain. This intervention requires a preoperative planning phase, with a millimetric accuracy, in which surgeons decide the best placement of the electrode depending on a set of surgical rules. However, brain tissues may deform during the surgery because of the brain shift phenomenon, leading the electrode to mistake the target, or moreover to damage a vital anatomical structure. In this paper, we present a patient-specific automatic planning approach for DBS procedures which accounts for brain deformation. Our approach couples an optimization algorithm with FEM based brain shift simulation. The system was tested successfully on a patient-specific 3D model, and was compared to a planning without considering brain shift. The obtained results point out the importance of performing planning in dynamic conditions.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01242851/file/EMBC%202015%20submission.pdf BibTex
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titre
Fracture in Augmented Reality
auteur
Nazim Haouchine, Alexandre Bilger, Jeremie Dequidt, Stephane Cotin
article
SIGGRAPH [Poster], Aug 2015, Los Angeles, United States. 2015
resume
We propose in this study an image-guided mesh cutting method to handle real-time augmentation of paper tearing. This method relies on the combination of visually-based fracture tracking algorithm and a physics-based model that is dynamically superimposed on the image.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01191090/file/template.pdf BibTex

2014

Conference papers

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titre
Intra-operative Registration for Stereotactic Procedures driven by a combined Biomechanical Brain and CSF Model
auteur
Alexandre Bilger, Éric Bardinet, Sara Fernández-Vidal, Christian Duriez, Pierre Jannin, Stéphane Cotin
article
ISBMS – International Symposium on Biomedical Simulation, Oct 2014, Strasbourg, France. 2014
resume
During stereotactic neurosurgery, the brain shift could affect the accuracy of the procedure. However, this deformation of the brain is not often considered in the pre-operative planning step or intra-operatively, and may lead to surgical complications, side effects or ineffectiveness. In this paper, we present a method to update the pre-operative planning based on a physical simulation of the brain shift. Because the simulation requires unknown input parameters, the method relies on a parameter estimation process to compute the intracranial state that matches the partial data taken from intra-operative modalities. The simulation is based on a biomechanical model of the brain and the cerebro-spinal fluid. In this paper, we show on an anatomical atlas that the method is numerically sound.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01058435/file/Bilger_ISBMS.pdf BibTex
pre-op-projection.png
titre
Intra-operative Registration for Deep Brain Stimulation Procedures based on a Full Physics Head Model
auteur
Alexandre Bilger, Eric Bardinet, Sara Fernández-Vidal, Christian Duriez, Pierre Jannin, Stéphane Cotin
article
MICCAI 2014 Workshop on Deep Brain Stimulation Methodological Challenges – 2nd edition, Sep 2014, Boston, United States. 2014
resume
Brain deformation is a factor of inaccuracy during stereotactic neurosurgeries. If this phenomenon is not considered in the pre-operative planning or intra-operatively, it could lead to surgical complications, side effects or ineffectiveness. In this paper, we present a patient-specific method to update the pre-operative planning based on a physical simulation of the brain shift. A minimization process estimates parameters of the simulation in order to compute the brain tissue deformation matching the partial data taken from intra-operative modalities. The simulation is based on a patient-specific biomechanical model of the brain and the cerebro-spinal fluid. We validate the method on a patient with a post-operative MRI.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-01060304/file/dbsmc14_Bilger.pdf BibTex
titre
Computation and Visualization of Risk Assessment in Deep Brain Stimulation
auteur
Alexandre Bilger, Christian Duriez, Stéphane Cotin
article
MMVR 21 – Medicine Meets Virtual Reality, Feb 2014, Manhattan Beach, California, United States. IOS Press, 2014
resume
Deep Brain Stimulation is a neurosurgical approach for the treatment of pathologies such as Parkinson’s disease. The basic principle consists in placing a thin electrode in a deep part of the brain. To safely reach the target of interest, careful planning must be performed to ensure that no vital structure (e.g. blood vessel) will be damaged during the insertion of the electrode. Currently this planning phase is done without considering the brain shift, which occurs during the surgery once the skull is open, leading to increased risks of complications. In this paper, we propose a method to compute the motion of anatomical structures induced by the brain shift. This computation is based on a biomechanical model of the brain and the cerebro-spinal fluid. We then visualize in a intuitive way the risk of damaging vital structures with the electrode.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-00881694/file/Bilger_A.pdf BibTex

Theses

titre
Patient-specific biomechanical simulation for deep brain stimulation
auteur
Alexandre Bilger
article
Modeling and Simulation. Université des Sciences et Technologie de Lille, 2014. English
resume
Deep brain stimulation is a neurosurgical treatment involving the permanent implantation of electrodes in the brain, to stimulate a specific deep structure. Electrical stimulation of some brain structures treats symptoms of motor or affective neurological disorders. The success of the operation relies on the electrode placement precision, which the goal is to maximize the therapeutic outcomes, and minimize the adverse effects. To do that, a pre-operative planning step determine the target coordinates to stimulate, as well as the electrode trajectory to reach it, thanks to a combination of medical images of the patient and numerical tools. However, intra-operative brain deformation, called brain shift, might invalidate the planning. The contributions of this thesis rely on a biomechanical model of brain shift which comprises a mechanical model for deformation, as well as a model of cerebrospinal fluid leak. We present a pre-operative tool, based on our model, in order to provide to the surgeon an information on the deformation risks, that he could use to select a safe trajectory for the patient, even in the case of brain shift. Moreover, we propose an intra-operative registration method based on our biomechanical model, in order to compute the new location of anatomical structures. Finally, thanks to a model of insertion of the electrode and its interaction with brain tissue, we reproduce the operating protocol in order to compute the electrode curvature due to brain shift.
Accès au texte intégral et bibtex
https://hal.inria.fr/tel-01097488/file/ABilger_thesis.pdf BibTex

2012

Conference papers

riskDistMapColorMapWithoutElectrode.jpg
titre
Brain-shift aware risk map for Deep Brain Stimulation Planning
auteur
Alexandre Bilger, Caroline Essert, Christian Duriez, Stéphane Cotin
article
DBSMC – MICCAI 2012 Workshop on Deep Brain Stimulation Methodological Challenges, Oct 2012, Nice, France. 2012
resume
In Deep Brain Stimulation surgery, the efficiency of the procedure heavily relies on the accuracy of the placement of the stimulating electrode. Meanwhile, the effectiveness of the placement is difficult due to brain shifts occurring during and after the procedure. We propose an approach to overcome the limitations of current planning software that ignores brain shift. In particular, we consider the motion of vascular structures in order to reduce risks of dissecting a vessel during the procedure. Facing the difficulty to produce an exact brain shift prediction, we propose to build a brain shift aware risk map which embeds the vascular motion risk. This risk map is extrapolated using simulation from clinical studies that provide statistics on the displacement of anatomical landmarks during the procedure. Risk maps can be directly integrated into automatic path planning algorithms to better predict optimal electrode trajectories. The method relies on a physics-based simulation that takes into account brain deformation, electrode placement, cerebrospinal fluid, and vascular motion. The goal is to reproduce the spread of brain shift situations that are noted in clinical studies. Preliminary results show that it is possible to compute safe electrode trajectories even in case of brain shift and yet optimal regarding the placement within the targeted area.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-00736773/file/miccai12.pdf BibTex

2011

Conference papers

titre
Biomechanical Simulation of Electrode Migration for Deep Brain Stimulation
auteur
Alexandre Bilger, Jérémie Dequidt, Christian Duriez, Stéphane Cotin
article
Gabor Fichtinger and Anne Martel and Terry Peters. 14th International Conference on Medical Image Computing and Computer-Assisted Intervention – MICCAI 2011, Sep 2011, Toronto, Canada. Springer, 6891/2011, pp.339-346, 2011, Lecture Notes in Computer Science; Medical Image Computing and Computer-Assisted Intervention – MICCAI 2011. <10.1007/978-3-642-23623-5_43>
resume
Deep Brain Stimulation is a modern surgical technique for treating patients who suffer from affective or motion disorders such as Parkinson’s disease. The efficiency of the procedure relies heavily on the accuracy of the placement of a micro-electrode which sends electrical pulses to a specific part of the brain that controls motion and affective symptoms. However, targeting this small anatomical structure is rendered difficult due to a series of brain shifts that take place during and after the procedure. This paper introduces a biomechanical simulation of the intra and postoperative stages of the procedure in order to determine lead deformation and electrode migration due to brain shift. To achieve this goal, we propose a global approach, which accounts for brain deformation but also for the numerous interactions that take place during the procedure (contacts between the brain and the inner part of the skull and falx cerebri, effect of the cerebro-spinal fluid, and biomechanical interactions between the brain and the electrodes and cannula used during the procedure). Preliminary results show a good correlation between our simulations and various results reported in the literature.
Accès au texte intégral et bibtex
https://hal.inria.fr/hal-00685737/file/fulltext_2_.pdf BibTex