Bernhard Geiger

European Space Astronomy Centre

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Alejandro Cardesín‐Moinelo

European Space Astronomy Centre

Jean‐Louis Roujean

Centre d'Études Spatiales de la Biosphère

C. Vallat

European Space Astronomy Centre

Marc Costa

European Space Astronomy Centre

B. Grieger

European Space Astronomy Centre

N. Altobelli

European Space Astronomy Centre

M. Kueppers

European Space Astronomy Centre

H. Svedhem

Delft University of Technology

Patrick Martin

European Space Astronomy Centre

Juan José García Beteta

European Space Astronomy Centre

Cooperative Institutions

Centre National de la Recherche Scientifique

European Space Astronomy Centre

Max Planck Institute for Solar System Research

Jet Propulsion Laboratory

Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

Max Planck Society

European Space Research and Technology Centre

Siemens Healthcare (Germany)

Siemens (Germany)

Siemens (United States)

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Evolution of the ion environment of comet 67P/Churyumov-Gerasimenko

Astronomy and Astrophysics (2015)

H. Nilsson Gabriella Stenberg Wieser E. Behar Cyril Simon Wedlund E. Kallio

Context. The Rosetta spacecraft is escorting comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 AU, where the comet activity was low, until perihelion at 1.24 AU. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation.

Sublimation

Comet dust

10.1051/0004-6361/201526142

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Citations (87)

Moderne Dosisregelungs-Konzepte und ihre Möglichkeiten für dosissparendes Arbeiten

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren (2007)

Bernhard Geiger

Moderne Röntgenanlagen bieten eine Vielzahl an technischen Konfigurationsmöglichkeiten und Bedienelementen für die Abstimmung von Aufnahme- und Bildverarbeitungsparametern. Dadurch ist eine flexible Anpassung an die jeweilige Anwendung möglich. Das Zusammenspiel dieser Parameter beeinflusst sowohl die Bildqualität als auch die Patientendosis und ist oft sehr komplex.

10.1055/s-2007-976615

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<title>Augmented-reality visualization of brain structures with stereo and kinetic depth cues: system description and initial evaluation with head phantom</title>

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2001)

Calvin R. Maurer Frank Sauer Bo Hu B. Bascle Bernhard Geiger

We are developing a video see-through head-mounted display (HMD) augmented reality (AR) system for image-guided neurosurgical planning and navigation. The surgeon wears a HMD that presents him with the augmented stereo view. The HMD is custom fitted with two miniature color video cameras that capture a stereo view of the real-world scene. We are concentrating specifically at this point on cranial neurosurgery, so the images will be of the patient's head. A third video camera, operating in the near infrared, is also attached to the HMD and is used for head tracking. The pose (i.e., position and orientation) of the HMD is used to determine where to overlay anatomic structures segmented from preoperative tomographic images (e.g., CT, MR) on the intraoperative video images. Two SGI 540 Visual Workstation computers process the three video streams and render the augmented stereo views for display on the HMD. The AR system operates in real time at 30 frames/sec with a temporal latency of about three frames (100 ms) and zero relative lag between the virtual objects and the real-world scene. For an initial evaluation of the system, we created AR images using a head phantom with actual internal anatomic structures (segmented from CT and MR scans of a patient) realistically positioned inside the phantom. When using shaded renderings, many users had difficulty appreciating overlaid brain structures as being inside the head. When using wire frames, and texture-mapped dot patterns, most users correctly visualized brain anatomy as being internal and could generally appreciate spatial relationships among various objects. The 3D perception of these structures is based on both stereoscopic depth cues and kinetic depth cues, with the user looking at the head phantom from varying positions. The perception of the augmented visualization is natural and convincing. The brain structures appear rigidly anchored in the head, manifesting little or no apparent swimming or jitter. The initial evaluation of the system is encouraging, and we believe that AR visualization might become an important tool for image-guided neurosurgical planning and navigation.

Optical head-mounted display

Frame rate

10.1117/12.428086

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Citations (31)

The CONSERT operations planning process for the Rosetta mission

2018 SpaceOps Conference (2018)

Yves Rogez P. Puget Sonia Zine Alain Hérique W. Kofman

10.2514/6.2018-2687

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New advances for imaging of laryngotracheal stenosis by post processing of spiral-CT data

Erich Sorantin C. Halmai B. Erdhelyi L. Martonossy K. Palagy

Laryngotracheal Stenosis

Spiral computed tomography

10.1007/978-3-7091-3707-9_30

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Virtual bronchoscopy of peripheral nodules using arteries as surrogate pathways

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2005)

Bernhard Geiger Atilla P. Kiraly David P. Naidich Carol L. Novak

The recent introduction of ultrathin bronchoscopy offers considerable promise for diagnosing even small peripheral lung nodules previously considered inaccessible for routine flexible bronchoscopy. However this requires obtaining an accurate roadmap prior to endoscopy. Although virtual bronchoscopy (VB) has proved to be a useful tool for planning transbronchial interventions involving the central airways, to date, VB has received little attention for providing roadmaps to peripheral lesions. This may be especially problematic, as ultrathin bronchoscopes can now access airways not visualized on routine high-resolution CT scanners. We propose to extend the reach of virtual bronchoscopy by using peripheral arteries as surrogates for peripheral bronchi that cannot be identified even with high-resolution CT technique. Since every bronchus is accompanied by an artery, it should hypothetically be possible to substitute one for another and derive useful navigational roadmaps. This paper presents a preliminary investigation of this concept, using a combination of virtual endoscopic techniques. Virtual angioscopic and bronchoscopic flythroughs are created and transition points are selected at points that can be easily identified on CT images as corresponding structures. The proximal bronchial path and the distal arterial path are then combined and presented as a single continuous flythrough. Our preliminary investigations show that as expected, the local geometry of the airway and corresponding artery are similar. In addition to visual inspection, we use the segmentation of the arterial and bronchial trees and their tree models. Selected paths from each tree model are compared by various similarity measures in order to demonstrate their correspondence. We anticipate that this technique for bronchoscopy planning will enable bronchoscopic evaluation of previously unreachable peripheral lung nodules.

10.1117/12.595734

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Use of a Kalman filter for the retrieval of surface BRDF coefficients with a time-evolving model based on the ECOCLIMAP land cover classification

Remote Sensing of Environment (2007)

Olivier Samain Jean‐Louis Roujean Bernhard Geiger

Albedo (alchemy)

Land Cover

10.1016/j.rse.2007.07.007

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Citations (52)

Steps Toward the Automatic Interpretation of 3D Images

Springer eBooks (1990)

Nicholas Ayache J. D. Boissonnat Laurent D. Cohen Bernhard Geiger Jacques Lévy Véhel

Representation

10.1007/978-3-642-84211-5_6

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Citations (41)

<title>Three-dimensional reconstruction of complex shapes based on the Delaunay triangulation</title>

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1993)

Jean‐Daniel Boissonnat Bernhard Geiger

We propose a solution to the problem of 3D reconstruction from cross-sections, based on the Delaunay triangulation of object contours. Its properties--especially the close relationship to the medial axis--enable us to do a compact tetrahedrization resulting in a nearest-neighbor connection. The reconstruction of complex shapes is improved by adding vertices on and inside contours.

10.1117/12.148710

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Citations (146)

P-946 Why do non smokers with non-small cell lung cancer (NSCLC) who receive erlotinib have better clinical outcomes than smokers?

Lung Cancer (2005)

Gary M. Clark Pablo J. Cagnoni Mieke Ptaszynski Marta Hamilton P. Santabárbara

10.1016/s0169-5002(05)81439-4

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Citations (2)