6 research outputs found
Articulated Clinician Detection Using 3D Pictorial Structures on RGB-D Data
Reliable human pose estimation (HPE) is essential to many clinical
applications, such as surgical workflow analysis, radiation safety monitoring
and human-robot cooperation. Proposed methods for the operating room (OR) rely
either on foreground estimation using a multi-camera system, which is a
challenge in real ORs due to color similarities and frequent illumination
changes, or on wearable sensors or markers, which are invasive and therefore
difficult to introduce in the room. Instead, we propose a novel approach based
on Pictorial Structures (PS) and on RGB-D data, which can be easily deployed in
real ORs. We extend the PS framework in two ways. First, we build robust and
discriminative part detectors using both color and depth images. We also
present a novel descriptor for depth images, called histogram of depth
differences (HDD). Second, we extend PS to 3D by proposing 3D pairwise
constraints and a new method that makes exact inference tractable. Our approach
is evaluated for pose estimation and clinician detection on a challenging RGB-D
dataset recorded in a busy operating room during live surgeries. We conduct
series of experiments to study the different part detectors in conjunction with
the various 2D or 3D pairwise constraints. Our comparisons demonstrate that 3D
PS with RGB-D part detectors significantly improves the results in a visually
challenging operating environment.Comment: The supplementary video is available at https://youtu.be/iabbGSqRSg
MĂ©thodes de radioprotection rĂ©actives au contexte pour la salle dâopĂ©ration hybride
The use of X-ray imaging technologies during minimally-invasive procedures exposes both patients and medical staff to ionizing radiation. Even if the dose absorbed during a single procedure can be low, long-term exposure can lead to noxious effects (e.g. cancer). In this thesis, we therefore propose methods to improve the overall radiation safety in the hybrid operating room by acting in two complementary directions. First, we propose approaches to make clinicians more aware of exposure by providing in-situ visual feedback of the ongoing radiation dose by means of augmented reality. Second, we propose to act on the X-ray device positioning with an optimization approach for recommending an angulation reducing the dose deposited to both patient and staff, while maintaining the clinical quality of the outcome image. Both applications rely on approaches proposed to perceive the room using RGBD cameras and to simulate in real-time the propagation of radiation and the deposited dose.Lâutilisation de systĂšmes dâimagerie Ă rayons X lors de chirurgies mini-invasives expose patients et staff mĂ©dical Ă des radiations ionisantes. MĂȘme si les doses absorbĂ©es peuvent ĂȘtre faibles, lâexposition chronique peut causer des effets nocifs (e.g. cancer). Dans cette thĂšse, nous proposons des nouvelles mĂ©thodes pour amĂ©liorer la sĂ©curitĂ© vis-Ă -vis des radiations ionisantes en salle opĂ©ratoire hybride dans deux directions complĂ©mentaires. PremiĂšrement, nous prĂ©sentons des approches pour rendre les cliniciens plus conscients des irradiations grĂące Ă des visualisations par rĂ©alitĂ© augmentĂ©e. DeuxiĂšmement, nous proposons une mĂ©thode d'optimisation pour suggĂ©rer une pose de lâimageur rĂ©duisant la dose au personnel et patient, tout en conservant la qualitĂ© de lâimage. Pour rendre ces applications possibles, des nouvelles approches pour la perception de la salle grĂące Ă des camĂ©ras RGBD et pour la simulation en temps-rĂ©el de la propagation et doses de radiation ont aussi Ă©tĂ© proposĂ©es
Evaluation of occupational exposure to static magnetic field in MRI sites based on body pose estimation and SMF analytical computation
International audienceThis paper tackles the problem of estimating exposure to static magnetic field (SMF) in magnetic resonance imaging (MRI) sites using a nonâinvasive approach. The proposed approach relies on a visionâbased system to detect people's body parts and on a mathematical model to compute SMF exposure. A multiâview camera system was used to capture the MRI room, and a visionâbased system was applied to detect body parts. The detected localization was then fed into a mathematical model to compute SMF exposure. In this study, we focused on exposure at the neck due to two main reasons. First, according to regulations, the limit of exposure at head and trunk for MR workers is higher than that for the general public. Second, it was easier to attach a dosimeter at the neck to perform measurements, which allowed a quantitative evaluation of our approach. This approach was applied to two scenarios simulating the daily movements of medical workers for which dosimeter measurements were also recorded. The results indicated that the proposed approach predicted occupational SMF exposure with reasonable accuracy compared with the dosimeter measurements. The proposed approach is a simple safe working procedure to estimate the exposure of MR workers at different parts of the body without wearing any marker detection. It can be applied to reduce occupational SMF exposure, without changes in workersâ performances. For that reason, our nonâinvasive proposed method can be used as a simple safety tool to estimate occupational SMF exposure in MR sites