The link alignment is a challenge in underwater wireless optical communication (UWOC). This paper proposes a UWOC system adopting a fisheye lens with a field of view (FOV) of ±90° at the receiver to alleviate alignment requirement, and a mobile scanning device (MSD) is exploited to track the variation of the imaging position generated by the fisheye lens due to different incidence angles. In a 7-m tap water channel, a transmission with a data rate of 400 Mbps and an FOV of ±90° is realized with 16-quadrature amplitude modulating-orthogonal frequency division multiplexing (16-QAM-OFDM) modulation and orthogonal matching pursuit (OMP) channel estimation algorithm.
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http://dx.doi.org/10.1364/OE.498180 | DOI Listing |
Dentomaxillofac Radiol
January 2025
Assist. Prof. Dr, Selcuk University Faculty of Medicine, Department of Radiation Oncology, Konya, 42130, Turkiye.
Objectives: Due to the increasing use of cone-beam computed tomography (CBCT) in dentistry and considering the effects of radiation on radiosensitive organs, the aim of this study was to investigate the effect of shielding on absorbed dose of eyes, thyroid and breasts in scans conducted with different parameters using two different fields of view (FOV).
Methods: Dose measurements were calculated on a tissue-equivalent female phantom by repeating each scanning parameter three times and placing at least two thermoluminescent dosimeters (TLD) on each organ, with the averages then taken. The same CBCT scans were performed in two different FOV with shielding including thyroid collar, radiation safety glasses and lead apron and without shielding.
Phys Med Biol
January 2025
Institute of High Energy Physics Chinese Academy of Sciences, 19B Yuquan Road, Shijingshan District, Beijing, Beijing, Beijing, 100049, CHINA.
Objective: Timing calibration is essential for positron emission tomography (PET) system as it enhances timing resolution to improve image quality. Traditionally, positron sources are employed for timing calibration. However, the photons emitted by these sources travel in opposite directions, necessitating that positrons annihilate at multiple locations to collect coincidence data across a greater number of lines of response (LORs).
View Article and Find Full Text PDFPhys Med Biol
January 2025
Department of Trauma and Reconstructive Surgery, BG Hospital Bergmanntrost, Merseburger Straße 165 06112 Halle, Halle, Sachsen-Anhalt, 06112, GERMANY.
The purpose of this study was to develop a robust deep learning approach trained with a small in-vivo MRI dataset for multi-label segmentation of all eight carpal bones for therapy planning and wrist dynamic analysis. Approach: A small dataset of 15 3.0-T MRI scans from five health subjects was employed within this study.
View Article and Find Full Text PDFBiomed Opt Express
January 2025
Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA.
The choroid, a critical vascular layer beneath the retina, is essential for maintaining retinal function and monitoring chorioretinal disorders. Existing imaging methods, such as indocyanine green angiography (ICGA) and optical coherence tomography (OCT), face significant limitations, including contrast agent requirements, restricted field of view (FOV), and high costs, limiting accessibility. To address these challenges, we developed a nonmydriatic, contrast agent-free fundus camera utilizing transcranial near-infrared (NIR) illumination.
View Article and Find Full Text PDFBiomed Opt Express
January 2025
Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland.
Cardiovascular imaging with camera-on-tip endoscopes has the potential to provide physiologically relevant data on the tissue state and device placement that can improve clinical outcomes. In this work, we review the unmet clinical need for image-based cardiovascular diagnostics and guidance for minimally invasive procedures. We present a 7 Fr camera-on-tip endoscope with fibre-coupled multispectral illumination that includes methods for imaging in a blood-filled field of view (FOV).
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