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Optically pumped magnetometer-based magnetoencephalography (OPM-MEG) offers significant advantages over traditional systems based on superconducting quantum interference devices, including flexibility and the ability to record brain activity without cryogenic cooling. However, OPM-MEG is highly susceptible to motion artifacts due to its sensitivity to external magnetic field fluctuations.To address this challenge, we propose an Adaptive Time-varying (ATH) Homogeneous field correction (HFC) method, which integrates time-varying HFC with adaptive filtering to suppress head motion artifacts. The ATH method estimates background magnetic field components induced by head movements and dynamically adjusts filter parameters to minimize discrepancies between measured signals and predicted background fields.We evaluated the ATH method through simulation studies and median nerve stimulation OPM-MEG experiments, demonstrating its effectiveness in enhancing signal quality and robustness across various experimental conditions.ATH offers an effective solution for motion artifact suppression in OPM-MEG systems. Its robustness under diverse conditions supports broader application in research and clinical settings.
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http://dx.doi.org/10.1088/1741-2552/adec1d | DOI Listing |
J Biomol NMR
September 2025
Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
Biomolecular dynamics in the microsecond-to-millisecond (µs-ms) timescale are linked to various biological functions, such as enzyme catalysis, allosteric regulation, and ligand recognition. In solution state NMR, Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments are commonly used to probe µs-ms timescale motions, providing detailed kinetic, thermodynamic, and mechanistic information at the atomic level. For investigating conformational dynamics in high-molecular-weight biomolecules, methyl groups serve as ideal probes due to their favorable relaxation properties, and C CPMG relaxation dispersion is widely employed for characterizing dynamics in selectively CH-labeled samples.
View Article and Find Full Text PDFHum Brain Mapp
September 2025
Department of Neuropediatrics, General Pediatrics, Diabetology, Endocrinology, Social Pediatrics, University Children's Hospital, Tübingen, Germany.
Subject motion is a significant problem for the analysis of functional MRI data and is usually described by "total displacement" or "scan-to-scan displacement". Neither parameter, however, takes into account voxel size, which clearly is relevant for the actual effects of motion on the data. Consequently, it is hitherto impossible to compare motion between subjects/studies acquired using different voxel dimensions, precluding the development of generally applicable recommendations for fMRI quality control procedures.
View Article and Find Full Text PDFPhotodiagnosis Photodyn Ther
September 2025
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China. Electronic address:
Purpose: To characterize the cavity hyperreflective-content and septum's motion artifact (CHASMA) in en face optical coherence tomography angiography (OCTA) across multiple ocular fundus abnormalities.
Methods: This was a cross-sectional, observational study. Subjects with extravascular OCTA signals arising from the cavity's hyperreflective-content and/or septum were enrolled.
Magn Reson Med
September 2025
A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.
Since its introduction more than 30 years ago, the blood oxygenation level-dependent (BOLD) contrast remains the most widely used method for functional MRI (fMRI) in humans and animal models. The BOLD contrast is typically acquired with echo planar imaging (EPI) to obtain sensitization of the signal during the echo time (TE) to dynamic changes in deoxyhemoglobin content, while achieving high spatiotemporal resolution and full brain coverage. However, EPI-based fMRI also faces multiple shortcomings, including sensitivity to body motion, susceptibility-related signal dropouts, interference with multimodal sensors, and loud acoustic noise.
View Article and Find Full Text PDFJ Appl Physiol (1985)
September 2025
Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, Kanagawa, Japan.
Muscle metaboreflex is activated in limb skeletal muscles during high-intensity exercise that increases respiratory demand, but its effects on respiratory muscle blood flow remain unknown. Therefore, we investigated whether metaboreflex activation in the forearm alters blood flow in the intercostal muscles. Sixteen healthy young male subjects performed isometric handgrip at 30% of maximal voluntary contraction for 2 minutes, followed by either post-exercise muscle ischemia (PEMI; metaboreflex activation condition) or a control recovery.
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