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1. Naked-Eye 3D Display Based on Microlens Array Using Combined Micro-Nano Imprint and UV Offset Printing Methods.

Author

Chen L, Chen G, Liao L, and Chen H

Subjects
Algorithms, Light, Printing, Three-Dimensional, Imaging, Three-Dimensional, Models, Theoretical, Visual Perception
Abstract

An optical film integrating microlens array (MLAs) and 3D micro-graphics is an important way to achieve the naked-eye 3D display effect. The 3D micro-graphics is traditionally generated by the micro-nano imprint technology based on precision engraving mold, which leads to high production cost and low production efficiency, and thus restricts the rapid response to production tasks and large-scale popularization and application. In this study, a process scheme for large-scale printing of 3D micro-graphics using UV offset printing based on presensitized (PS) plate was proposed, matching with the MLAs fabricated by micro-nano imprint process to achieve naked-eye 3D display effect. We used the laser confocal microscope to systematically measure and analyze the geometric and optical performance of the fabricated MLAs in terms of height, curvature radius, center distance, spacing, focal length, and numerical aperture, and evaluated the influence of the publishing resolution of the PS plate on the display effect of 3D micro-graphics. The printing quality and display effect of 3D micro-graphics were further improved by adjusting process parameters such as printing speed and printing pressure. The results of the current study demonstrate that the combined application of micro-nano imprint technology based on precision mold and UV offset printing technology based on PS plate can achieve an excellent naked-eye 3D display effect in 360° all angles, which is efficient, cost-saving, and highly flexible.

Published
2020
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2. Three-dimensional Simulation of Quantitative Ultrasound in Cancellous Bone using the Echographic Response of a Metallic Pin

Author

Yoshiki Nagatani, Salah Naili, Vu-Hieu Nguyen, Séraphin Guipieri, Guillaume Haїat, Christine Chappard, Didier Geiger, Department of Electronics [Kobe, Japan], Kobe City College of Technology [Kobe, Japan], Institut Mondor de Recherche Biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire de Modélisation et Simulation Multi Echelle (MSME), Université Paris-Est Marne-la-Vallée (UPEM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Bioingénierie et Bioimagerie Ostéo-articulaires, Biomécanique et Biomatériaux Ostéo-Articulaires (B2OA (UMR_7052)), École nationale vétérinaire - Alfort (ENVA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), This study was supported in part by KAKENHI (Grant Number 25871038 and 16K01431) from the Japan Society for the Promotion of Science (JSPS) and the PRTS program (project OsseoWave n°ANR-13-PRTS-0015-02) of French National Research Agency (ANR). This paper has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 682001, project ERC Consolidator Grant 2015 BoneImplant)., Haiat, Guillaume, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-IFR10, Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-École nationale vétérinaire d'Alfort (ENVA), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris-Est Marne-la-Vallée (UPEM)

Subjects
FDTD Simulation, Materials science, Swine, FOS: Physical sciences, 3d model, Reflector (antenna), Physics - Classical Physics, Bone Nails, 01 natural sciences, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Spine surgery, Imaging, Three-Dimensional, 0103 physical sciences, medicine, Animals, Radiology, Nuclear Medicine and imaging, Femur, 010301 acoustics, Ultrasonography, Discopathy, Radiological and Ultrasound Technology, 3D Model, Soft tissue, Classical Physics (physics.class-ph), Physics - Medical Physics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Vertebral body, Quantitative ultrasound, Three dimensional simulation, medicine.anatomical_structure, Metals, Models, Animal, Cancellous Bone, Medical Physics (physics.med-ph), Quantitative ultrasound (QUS), [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Cancellous bone, Biomedical engineering
Abstract

Degenerative discopathy is a common pathology that may require spine surgery. A metallic cylindrical pin is inserted into the vertebral body to maintain soft tissues and may be used as a reflector of ultrasonic wave to estimate bone density. The first aim of this paper is to validate a three-dimensional (3-D) model to simulate the ultrasonic propagation in a trabecular bone sample in which a metallic pin has been inserted. We also aim at determining the effect of changes of bone volume fraction (BV/TV) and of positioning errors on the quantitative ultrasound (QUS) parameters in this specific configuration. The approach consists in coupling finite-difference time-domain simulation with X-ray microcomputed tomography. The correlation coefficient between experimental and simulated speed of sound (SOS)—respectively, broadband ultrasonic attenuation (BUA)—was equal to 0.90 (respectively, 0.55). The results show a significant correlation of SOS with BV/TV ( R = 0.82), while BUA values exhibit a nonlinear behavior versus BV/TV. The orientation of the pin should be controlled with an accuracy of around 1° to obtain accurate results. The results indicate that using the ultrasonic wave reflected by a pin has a potential to estimate the bone density. SOS is more reliable than BUA due to its lower sensitivity to the tilt angle.

Published
2017