This paper presents a structural health monitoring system for monitoring, with reduced visual impact, one historical building structure. The is based on fiber Bragg gratings and comprises 19 displacement sensors 5 temperature sensors. All the were custom made according to points' characteristics. results obtained over first year of are presented. objective this work gather data that will bring deeper knowledge how structure behaves help planning recovering interventions in building.

We used a pair of Bragg gratings written in high birefringence fibre optics to measure, simultaneously, longitudinal and transverse strain temperature. The are superimposed the same position optic, so as behave punctual sensor. sensitivity spectral response device strain, temperature all characterized, results its application three-parameter sensor also presented.

The aim of this work is to show the possibility using fiber optic sensors instrument inside parts an artificial maxilla and measure internal tension transmitted by orthodontic orthopedic appliances dentition adjacent bone. Bragg gratings written in a standard optical were used monitor maxillary teeth multiplexed was surface bone, transversally longest axis teeth. A Universal Test Machine evaluate sensitivity sensor vertical lateral forces applied on wavelength shift approximately 0.30 nm...

This study describes a localized method – using optical fiber Bragg gratings (FBGs) to determine the human bite force at very moment of occlusion, in maximum intercuspidation. The FBG was encapsulated silicone splint between uppers and lowers first molars avoiding pre-contact with other teeth dentition model. Gypsum dental castings two volunteers are performed semi-adjustable articulator occluded situation maintain angulations occlusal plane within normal occlusion. sensor characterized...

The use of fibre Bragg grating sensors to study dental materials like resin-based composite and gypsum products is reported. Two commercially available resins three types were tested in order determine polymerization contraction setting expansion. Temperature strain evolution during the hardening phase material also obtained. presented technique can be a good tool for dentists better manipulate predict how it will behave vivo.

Instead of using the control teeth, we tried to prepare standard specimens derive equations for calculation age (analytical curves) with respect each kind tooth various ages. To specimens, determined racemization ratio teeth known that had actually been used appraisal chronological (total teeth). Then mixed commercially available L-Asp and D-Asp in same D/L as measured one total teeth. As a result, were able obtain rate from age-specific central lateral incisors. These closely similar those...

Fibre optic Bragg gratings (FBGs) written in normal and reduced diameter high birefringence (HiBi) fibres are studied. Chemical etching is used to reduce the of while optical properties FBG spectrum measured. The results obtained agree qualitatively with stress enhanced chemical etching. fibre determined as a function diameter. Optical characterization under transverse strain temperature also performed. show feasibility simultaneous measurement those parameters HiBi sensor.

Bragg gratings written in high-birefringence fibre optics are a key element the simultaneous measurement of transversal strain components and temperature, they have several applications as single polarisation optical filters for wavelength division multiplexing (WDM) applications. Precise determination grating characteristics is needed to aid device design, particularly taking into account illuminating light. The authors report results concerning production characterisation high...

HiBi FBG are used to demonstrate a technique evaluate orthodontic forces. The experiments performed in an artificial maxilla supporting dental wax and metal teeth. teeth instrumented using loads applied representing auxiliary appliance. values of the (extra-oral) based on clinical applications. It is demonstrated that tooth vestibular surface subject force 0.13 N. size sensitivity allow for determination forces orthogonally

We report the use of optical fiber sensors for monitoring rhythmic masticatory muscle activity during sleep bruxism episodes, which represents an original approach. Our work measured hyperactivity a volunteer wearing different types occlusal devices that were instrumented by Bragg grating sensors. compare results obtained with two device materials (rigid and resilient). also investigated thermal images infrared camera before after sleeping period, to observe associated temperature changes....

An optical fiber micro-channel sensor assisted by Bragg gratings is presented in this study. The was fabricated femtosecond laser micromachining. based on intensity demodulation with compensation for fluctuations and characterized blends of different refractive indices infused into the micro-channel. reflected signal grating discloses a linear increase related to index sample. average sensitivity obtained (92 ± 2) dBm/RIU.

The aim of the study is to develop a new punctual method determine human bite force, between uppers and lowers first molars, at moment occlusion in maximum intercuspation. Fibre optic Bragg gratings are encapsulated an acetate splint made by casting volunteer lower dentition. Splint sensor was positioned into mouth be pressured with minimal occlusal interference. transversal pressure on FBG acquired before (free), biting. measured forces were 12N during 28N right molars.

The aim of the study is to demonstrate potential fibre Braggs grating (FBG) in measurement different jaw movements that are performed for patients with occlusal parafunction using splints. Two silicon plates each 2mm used, optic sensor positioned maxillary left first molar region above point contact opposing tooth after pressing plate on model. Then second pressed. device has a final thickness 2 mm. splint installed mouth patient who underwent splint. maximum frequency bite monitored....

Regenerated fiber Bragg grating (RFBG) sensors for thermal aging at high temperatures from 600 °C to 1000 are produced and analyzed in this work. Seed FBGs regenerated 850 °C–900 characterized the increasing steps of 50 °C–100 °C. Signal decay is measured reflected spectra until imminent erasure. The objective analyze RFBG lifetime above regeneration temperature long periods after annealing cycles with levels. Lifetime results were reported be a few hours their temperature. Our significantly...

Get PDF Email Share with Facebook Tweet This Post on reddit LinkedIn Add to CiteULike Mendeley BibSonomy Citation Copy Text M. W. Schiller, I. Abe, P. Carvalho, Lopes, L. R. N. Nogueira, J. Pinto, and A. Simões, "On the Use of FBG Sensors Assess Performance a Dental Implant System," in Optical Fiber Sensors, OSA Technical Digest (CD) (Optica Publishing Group, 2006), paper ThE77. Export BibTex Endnote (RIS) HTML Plain alert Save article

This paper reports on the writing of long period gratings (LPGs) in a six-ring pure silica solid core, and large mode area photonic crystal fiber (fiber core diameter ρ = 10.1 μm) using CO2 laser system, characterization their strain temperature sensitivities. Temperature sensitivities order −19.6 pm/°C −88 pm/μɛ, respectively, were obtained, which comparable or surpassed values similar (PCF)-based LPG sensor configurations found literature.

The use of Fibre Bragg Grating sensors to study the setting expansion dental materials like resin based composites and gypsum is reported. Temperature strain evolution during hardening phase material are obtained.