29 research outputs found
Structural Olfactory Nerve Changes in Patients Suffering from Idiopathic Intracranial Hypertension
BACKGROUND: Complications of idiopathic intracranial hypertension (IIH) are usually caused by elevated intracranial pressure (ICP). In a similar way as in the optic nerve, elevated ICP could also compromise the olfactory nerve system. On the other side, there is growing evidence that an extensive lymphatic network system around the olfactory nerves could be disturbed in cerebrospinal fluid disorders like IIH. The hypothesis that patients with IIH suffer from hyposmia has been suggested in the past. However, this has not been proven in clinical studies yet. This pilot study investigates whether structural changes of the olfactory nerve system can be detected in patients with IIH. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-three patients with IIH and 23 matched controls were included. Olfactory bulb volume (OBV) and sulcus olfactorius (OS) depth were calculated by magnetic resonance techniques. While mean values of total OBV (128.7±38.4 vs. 130.0±32.6 mm(3), p=0.90) and mean OS depth (8.5±1.2 vs. 8.6±1.1 mm, p=0.91) were similar in both groups, Pearson correlation showed that patients with a shorter medical history IIH revealed a smaller OBV (r=0.53, p<0.01). In untreated symptomatic patients (n=7), the effect was greater (r=0.76, p<0.05). Patients who suffered from IIH for less than one year (n=8), total OBV was significantly smaller than in matched controls (116.6±24.3 vs. 149.3±22.2 mm(3), p=0.01). IIH patients with visual disturbances (n=21) revealed a lower OS depth than patients without (8.3±0.9 vs. 10.8±1.0 mm, p<0.01). CONCLUSIONS/SIGNIFICANCE: The results suggest that morphological changes of the olfactory nerve system could be present in IIH patients at an early stage of disease
Monitoring the energy efficiency of buildings with Raman DTS and embedded optical fiber cables
23rd International Conference on Optical Fibre Sensors, Santander, SPAIN, JUN 02-06, 2014International audienceTo reduce greenhouse gas emissions and to promote energy savings in the building sector, a project named Batimetre has been set-up, to measure parameters affecting building energy consumption. For the first time, optical fibers have been deployed on internal and external faces of two experimental houses, designed for low energy consumption. With a DTS Raman system, these cables provide a distributed measurement of walls temperature every meter and every two minutes. Such instrumentation is able to deliver a very large number of data at a reduced operating cost. It allows to isolate thermal phenomena in dynamic thermal simulation tools, and to compare several intermediate predicted and measured parameters
Câbles-capteurs à fibres optiques pour les mesures réparties Brillouin, Raman et Rayleigh dédiées à la surveillance des structures
International audienceCes dernières années, les avancées technologiques dans le domaine de la mesure ont conduit à rendre progressivement disponibles sur le marché des instrumentations optoélectroniques performantes, fondées sur les phénomènes de rétrodiffusion Raman, Brillouin et Rayleigh dans la silice constituant les fibres. Ces phénomènes physiques, exploités dans des systèmes réflectométriques (en anglais : OTDR – Optical Time-Domain Reflectometry), permettent de mesurer le profil des paramètres (température, déformations, courbure, fuite, pression, …) le long de la fibre déployée, sur des portées le plus souvent multi-kilométriques.Dans cette publication, nous décrivons le développement, la qualification métrologique, la fabrication industrielle en très grandes longueurs (10 km) de plusieurs câbles optiques de mesure dédiés. Les contraintes du déploiement de ces câbles en situation réelle (conditionnement, transport, installation, raccordement optique en conditions de terrain) sont détaillées de même que la mise en oeuvre des instrumentations optoélectroniques disponibles (dites aussi "systèmes de mesure" ou "interrogateurs")
Conjunctival scarring after eyelid surgery as first sign of ocular cicatricial pemphigoid.
Diagnosis of ocular cicatricial pemphigoid (OCP), a chronic cicatrizing autoimmune disease of the conjunctiva, may be difficult in the early stages of the disease. We noted abnormal conjunctival scarring in three patients who had undergone eyelid and strabismus surgery, which caused us to suspect OCP. In all three patients who subsequently underwent conjunctival biopsy, immunoglobulin or complement in the basement membrane zone detected by direct immunofluorescence helped establish the diagnosis. Although OCP typically is a disease of the elderly, the three patients in this study were aged \u3c 50 years; one patient was 19 years old. The present study demonstrates that a diagnosis of OCP should be considered for patients who develop abnormal conjunctival scarring after eyelid or strabismus surgery