This paper describes an intensity-modulated fiber optic sensor for strain measurements. The sensing element is a polydimetilsiloxane (PDMS) micro-diffraction grating, 15 mm long, 2 mm thick, with channels 150 µm wide, spaced apart 200 µm. The working principle of the sensor can be summarized as follows: when the sensing element is strained perpendicularly to the grating plane, light passing through the grating undergoes a modulation caused by the phenomenon of diffraction. Since the grating is interposed between a laser source and a fiber optic, the coupled radiation intensity between these two optical elements can be considered as an indirect measure of strain. A static calibration of the measuring system has been performed, showing that the device, with measuring range of about 0.04, is capable to discriminate strain of 0.005 and it presents a sensitivity increase with strain in the whole range of measurements.
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http://dx.doi.org/10.1109/EMBC.2012.6347310 | DOI Listing |
Small
January 2025
State Key Laboratory of Biocatalysis and Enzyme Engineering, Stem Cells and Tissue Engineering Manufacture Center, School of Life Science, Hubei University, Wuhan, Hubei, 430062, China.
Recent advances in drug design and compound synthesis have highlighted the increasing need for effective methods of toxicity evaluation. A specialized force sensor, known as the light wavelength-encoded "Chinese guzheng" is developed. This innovative sensor is equipped with optical fiber strings and utilizes a wavelength-encoded fiber Bragg grating (FBG) that is chemically etched to reduce its diameter.
View Article and Find Full Text PDFTuneable, variable, optical attenuation through an optical circulator with a broad, linear attenuation range of Δ ∼ (30-40) dB is demonstrated using non-reciprocal Faraday rotation in a double-pass configuration with a combination of permanent magnets and an electromagnet. A fiber-coupled magneto-optical variable optical attenuator (MVOA) operates over the near IR with an attenuation tuning range of Δ > 30 dB, a resolution of Δ ∼ 0.02 dB, a response time of < 2 ms, and a temperature dependence over = 25-70°C of Δ / Δ = -8 × 10 dB/°C.
View Article and Find Full Text PDFThe inertial element of a solid block is commonly used as the proof mass in traditional accelerometers. However, it is challenging to accommodate both the high-density solid-state proof mass and the highly elastic component simultaneously in a miniature sensor, which makes it difficult for the sensors to maintain comparable sensing performance at a miniaturized size. Here, a novel, to the best of our knowledge, liquid metal-based fiber optic accelerometer (LMFOA) is proposed for the first time to meet this requirement.
View Article and Find Full Text PDFPhotodiagnosis Photodyn Ther
January 2025
Department of Ophthalmology, Fuyang Hospital Affiliated to Bengbu Medical University(Fuyang People's Hospital), Fuyang, 236400, Anhui Province, China. Electronic address:
Purpose: To evaluate optic disc and macular microvasculature changes in children with anisometropic amblyopia before and after treatment.
Methods: In all, 60 children with unilateral anisometropic amblyopia between the ages of 6 and 12 were randomly selected from the ophthalmology clinic of Fuyang People's Hospital, while 60 children with non-amblyopia in the same age range were randomly selected as a normal control group. The right eye was uniformly taken in the control group with at least 6 months of follow-up.
J Neurol
January 2025
Jacobs Comprehensive MS Treatment and Research Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
Background: Previous investigations on optical coherence tomography (OCT) in multiple sclerosis (MS) focused on generalizable macular and peri-papillary regions without considering the anatomic variations of the retinal layer thickness.
Objective: This study aimed to assess the utility of parafoveal retinal layer thickness measured by OCT, underscoring its relationships with clinical outcomes in MS.
Methods: In this cross-sectional study, 214 people with MS (pwMS) and 57 age- and sex-matched healthy controls (HCs) were enrolled.
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