An efficient three-dimensional shape measurement system is proposed, which is based on the combining projection of single digital speckle pattern and phase-shifting fringe patterns. At the beginning, the initial corresponding point for each pixel is obtained by a novel speckle-phase combination method. The initial information can be calculated by the single speckle pattern in a short time, while the phase information is used to ensure the results. Unlike the conventional methods, it is not necessary to obtain the unwrapped phase, therefore the number of projected patterns is reduced greatly. Then accurate corresponding coordinates are obtained according to the wrapped phase. Three cases are analyzed while adjusting the initial corresponding coordinates locally. Thus accuracy coordinates are obtained without missing or incorrect points. Experiments demonstrate that we can achieve accurate reconstruction results with reduced measurement time by the proposed method.
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http://dx.doi.org/10.1364/OE.24.017686 | DOI Listing |
Sci Rep
December 2024
Department of Orthopaedics and Traumatology, The University of Hong Kong, Pok Fu Lam, Hong Kong.
Establishing normative values and understanding how proprioception varies among body parts is crucial. However, the variability across individuals, especially adolescents, makes it difficult to establish norms. This prevents further investigation into classifying patients with abnormal proprioception.
View Article and Find Full Text PDFNPJ Sci Learn
December 2024
Academy of Medical Engineering and Translational Medicine (AMT), Tianjin University, Tianjin, China.
Generalization is central to motor learning. However, few studies are on the learning generalization of BCI-actuated supernumerary robotic finger (BCI-SRF) for human-machine interaction training, and no studies have explored its longitudinal neuroplasticity mechanisms. Here, 20 healthy right-handed participants were recruited and randomly assigned to BCI-SRF group or inborn finger group (Finger) for 4-week training and measured by novel SRF-finger opposition sequences and multimodal MRI.
View Article and Find Full Text PDFNat Commun
December 2024
Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.
Taking advantage of the good mechanical strength of expanded Drosophila brains and to tackle their relatively large size that can complicate imaging, we apply potassium (poly)acrylate-based hydrogels for expansion microscopy (ExM), resulting in a 40x plus increased resolution of transgenic fluorescent proteins preserved by glutaraldehyde fixation in the nervous system. Large-volume ExM is realized by using an axicon-based Bessel lightsheet microscope, featuring gentle multi-color fluorophore excitation and intrinsic optical sectioning capability, enabling visualization of Tm5a neurites and L3 lamina neurons with photoreceptors in the optic lobe. We also image nanometer-sized dopaminergic neurons across the same intact iteratively expanded Drosophila brain, enabling us to measure the 3D expansion ratio.
View Article and Find Full Text PDFNat Commun
December 2024
Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.
Extending ferroelectric materials to two-dimensional limit provides versatile applications for the development of next-generation nonvolatile devices. Conventional ferroelectricity requires materials consisting of at least two constituent elements associated with polar crystalline structures. Monolayer graphene as an elementary two-dimensional material unlikely exhibits ferroelectric order due to its highly centrosymmetric hexagonal lattices.
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