Field of view

视野
  • 文章类型: Journal Article
    光片荧光显微镜(LSFM)已成为一种强大而通用的成像技术,以其卓越的功能而闻名,包括高速三维层析成像,最小的光漂白,和低光毒性。干涉光片荧光显微镜,具有更大的视场(FOV)和更均匀的轴向分辨率,在生物学和医学领域具有广泛的应用潜力。
    这项研究的目的是研究LSFM中多个光片(LS)之间的干扰行为,并优化光片荧光显微镜的FOV和分辨率。
    我们通过理论推导和数值模拟对LS之间的干扰效应进行了详细研究,旨在找到最优参数。随后,我们构建了一个定制的多LSFM系统,该系统包含干涉光片(ILS)和非干涉光片配置。我们进行了光束成像和微球成像测试,以评估这些系统的FOV和轴向分辨率。
    使用我们定制设计的光片荧光显微镜,我们捕获了干涉和非干涉光片(NILS)的强度分布曲线。此外,我们对微球进行了成像测试,以评估其成像结果.与NILS相比,ILS不仅表现出更大的FOV,而且还表现出更均匀的轴向分辨率。
    通过有效地调制多个LS之间的干扰,可以优化LS的强度分布,展开FOV,并实现更均匀的轴向分辨率。
    UNASSIGNED: Light-sheet fluorescence microscopy (LSFM) has emerged as a powerful and versatile imaging technique renowned for its remarkable features, including high-speed 3D tomography, minimal photobleaching, and low phototoxicity. The interference light-sheet fluorescence microscope, with its larger field of view (FOV) and more uniform axial resolution, possesses significant potential for a wide range of applications in biology and medicine.
    UNASSIGNED: The aim of this study is to investigate the interference behavior among multiple light sheets (LSs) in LSFM and optimize the FOV and resolution of the light-sheet fluorescence microscope.
    UNASSIGNED: We conducted a detailed investigation of the interference effects among LSs through theoretical derivation and numerical simulations, aiming to find optimal parameters. Subsequently, we constructed a customized system of multi-LSFM that incorporates both interference light sheets (ILS) and noninterference light-sheet configurations. We performed beam imaging and microsphere imaging tests to evaluate the FOV and axial resolution of these systems.
    UNASSIGNED: Using our custom-designed light-sheet fluorescence microscope, we captured the intensity distribution profiles of both interference and noninterference light sheets (NILS). Additionally, we conducted imaging tests on microspheres to assess their imaging outcomes. The ILS not only exhibits a larger FOV compared to the NILS but also demonstrates a more uniform axial resolution.
    UNASSIGNED: By effectively modulating the interference among multiple LSs, it is possible to optimize the intensity distribution of the LSs, expand the FOV, and achieve a more uniform axial resolution.
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  • 文章类型: Journal Article
    锥形束计算机断层扫描(CBCT)是介入放射学中广泛使用的成像技术。尽管CBCT在提高对复杂血管结构的理解和指导治疗决策方面具有很大的优势,其额外的辐射暴露程度也引起了相当大的关注。在这项研究中,我们旨在评估在介入手术期间接受头腹部CBCT扫描的患者的辐射暴露及其影响因素.本回顾性研究共纳入752例患者。使用剂量面积乘积(DAP)和参考空气角化(RAK)作为患者剂量的量度。结果表明,头部CBCT的DAP中值为53.8(50.5-64.4)Gy·cm2,腹部为47.4(39.6-54.3)Gy·cm2。男性性别和体重指数(BMI)的特征是头部和腹部CBCT扫描中DAP和RAK值增加。较大的FOV大小与较高的DAP但较低的RAK值相关,尤其是在头部CBCT扫描中。自动暴露控制(AEC)下的暴露参数也根据患者BMI和性别而变化。总之,患者接受头部CBCT扫描的辐射剂量略高于腹部.BMI,性别,和FOV大小是影响CBCT扫描期间患者辐射剂量的关键因素。我们的结果可能有助于确定和减少患者的辐射暴露。
    Cone-beam computed tomography (CBCT) is a widely used imaging technique in interventional radiology. Although CBCT offers great advantages in terms of improving comprehension of complex angioarchitectures and guiding therapeutic decisions, its additional degree of radiation exposure has also aroused considerable concern. In this study, we aimed to assess radiation exposure and its influential factors in patients undergoing CBCT scans of the head and abdomen during interventional procedures. A total of 752 patients were included in this retrospective study. Dose area product (DAP) and reference air kerma (RAK) were used as measures of patient dose. The results showed that the median values of DAP were 53.8 (50.5-64.4) Gy⋅cm2 for head CBCT and 47.4 (39.6-54.3) Gy⋅cm2 for that of the abdomen. Male gender and body mass index (BMI) were characterized by increased DAP and RAK values in both head and abdominal CBCT scans. Larger FOV size was associated with a higher DAP but a lower RAK value, especially in head CBCT scans. Exposure parameters under automatic exposure control (AEC) also varied according to patient BMI and gender. In conclusion, the patients received slightly higher radiation doses from head CBCT scans than from those applied to the abdomen. BMI, gender, and FOV size were the key factors that influenced the radiation dose administered to the patients during CBCT scans. Our results may help to define and minimize patients\' exposure to radiation.
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  • 文章类型: Journal Article
    视场和单星测量精度是评估星敏感器性能的关键指标。视场确定了传感器可以捕获的恒星的空间范围,而单星测量精度决定了星敏感器姿态确定和控制的精度。传统星敏感器的光学系统受到成像关系的制约。一旦确定了探测器,提高视场或单星测量精度将导致另一个的退化。为了解决这个问题,我们提出了一种用于星敏感器的光学系统,其精度性能随视场而变化。通过控制光学系统的场焦距与视场的关系,可以同时提高视场和单星测量精度。我们设计了相应的光学系统,以满足提高单星测量精度和视场的要求。设计成果证实了这类星敏感器的可行性。星敏感器能够同时满足星图识别和姿态确定的要求,空间导航等领域具有广阔的应用前景。
    The field of view and single-star measurement accuracy are crucial metrics for assessing the performance of a star sensor. The field of view determines the spatial range of stars that can be captured by the sensor, while the single-star measurement accuracy determines the precision of attitude determination and control for the star sensor. The optical system of conventional star sensors is constrained by imaging relationships. Once the detector is determined, improving either the field of view or the single-star measurement accuracy will result in the degradation of the other. To address this issue, we propose an optical system for star sensors with accuracy performance varying with the field of view. By controlling the relationship between the field focal length of the optical system and the field of view, it is possible to simultaneously enhance both the field of view and the single-star measurement accuracy. We have designed corresponding optical systems to address the requirements for improving the single-star measurement accuracy and field of view. The design results confirm the feasibility of this star sensor. The star sensors are capable of simultaneously meeting the requirements for star pattern recognition and attitude determination, presenting broad application prospects in fields such as space navigation.
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  • 文章类型: Journal Article
    OBJECTIVE: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury.
    METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively.
    RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway.
    CONCLUSIONS: Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
    目的: 探讨视交叉及其后部视路损伤所致视野缺损的特点及其客观评定方法。方法: 选择视交叉、视束、视放射及视皮质损伤所致视野缺损典型案例,分别进行视野、视觉诱发电位(visual evoked potential,VEP)、多焦视觉诱发电位(multifocal visual evoked potential,mfVEP)检查以及颅脑CT或MRI、视网膜光学相干断层扫描(optical coherence tomography,OCT),并对上述视觉电生理指标及神经影像学指标进行综合分析。结果: 视交叉损伤所致视野缺损的电生理学表现为双颞侧偏盲型mfVEP异常;视束、视放射及视皮质损伤所致视野缺损均表现为病变对侧的同向性偏盲型mfVEP异常。视束损伤出现偏盲眼轻度相对性传入性瞳孔障碍(relative afferent pupil disorder,RAPD)及特征性视神经萎缩表现,视放射、视皮质损伤则无此表现。神经影像学可为视交叉及其后部视路损伤提供形态学证据。结论: 视交叉、视束、视放射及视皮质损伤所致视野缺损具有各自特点,通过mfVEP视野与静态视野检查的联合应用,结合神经影像学检查,可最大程度地评价视路受损的部位和程度,为此类损伤的认定提供有效方案。.
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  • 文章类型: Journal Article
    目的:高能量和大视场(FOV)相衬成像对于生物学甚至医学应用至关重要。尽管有些作品致力于通过弯曲光栅等在高能量下实现大视场,这在医学高能成像中极具挑战性。
    方法:我们分析了高能X射线Talbot-Lau干涉仪(XTLI)中平面光栅的角阴影效应。然后,我们设计并开发了一个与微阵列阳极结构靶源耦合的逆XTLI,在高能量下扩展FOV。
    结果:我们的实验结果表明,在反XTLI中,源的益处以及在40keV下实现了水平方向上106.6mm的大FOV。基于这个系统,小鼠的实验证明了相位对比模式在肺组织成像中的潜在优势。
    结论:我们使用微阵列阳极结构的目标源与反向几何形状耦合,在紧凑型XTLI中扩展了FOV,这消除了光栅G0并减轻了G2的制造难度。我们相信所建立的设计思想和成像系统将促进XTLI在高能相衬成像中的广泛应用。
    Objective. High energy and large field of view (FOV) phase contrast imaging is crucial for biological and even medical applications. Although some works have devoted to achieving a large FOV at high energy through bending gratings and so on, which would be extremely challenging in medical high energy imaging.Approach.We analyze the angular shadowing effect of planar gratings in high-energy x-ray Talbot-Lau interferometer (XTLI). Then we design and develop an inverse XTLI coupled with a microarray anode-structured target source to extend the FOV at high energy.Main results.Our experimental results demonstrate the benefit of the source in the inverse XTLI and a large FOV of 106.6 mm in the horizontal direction is achieved at 40 keV. Based on this system, experiments of a mouse demonstrate the potential advantage of phase contrast mode in imaging lung tissue.Significance.We extend the FOV in a compact XTLI using a microarray anode-structured target source coupled with an inverse geometry, which eliminates grating G0 and relaxes the fabrication difficulty of G2. We believe the established design idea and imaging system would facilitate the wide applications of XTLI in high energy phase contrast imaging.
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  • 文章类型: Journal Article
    基于Risley棱镜的图像传感器可以通过光束控制来扩展成像视野。棱镜的顶角越大,视野的放大倍数越高,但同时,它加剧了成像像差的问题,这也对基于Risley棱镜的图像传感器的像差校正方法提出了更高的要求。为了提高速度,准确度,和像差校正过程的稳定性,提出了一种基于两轴转台的Risley棱镜图像传感器的自动校准方法。使用双轴转台获取具有不同棱镜旋转角度和物距的校准板的图像数据集。然后,使用双三次插值算法对校准板的图像进行预处理。最后计算出校准参数,并进行参数优化。实验结果验证了该自动标定方法的可行性。当成像传感器与物体的距离为3.6m时,校准的重投影误差在0.26像素内,并观察到精细的像差校正结果。
    Risley-prism-based image sensors can expand the imaging field of view through beam control. The larger the top angle of the prism, the higher the magnification of the field of view, but at the same time, it aggravates the problem of imaging aberrations, which also puts higher requirements on the aberration correction method for the Risley-prism-based image sensor. To improve the speed, accuracy, and stability of the aberration correction process, an automatic calibration method for the Risley-prism-based image sensor is proposed based on a two-axis turntable. The image datasets of the calibration plate with different prism rotation angles and object distances are acquired using a two-axis turntable. Then, the images of the calibration plate are pre-processed using the bicubic interpolation algorithm. The calibration parameters are finally calculated, and parameter optimization is performed. The experimental results verify the feasibility of this automated calibration method. The reprojection error of the calibration is within 0.26 pixels when the distance of the imaging sensor is 3.6 m from the object, and the fine aberration correction results are observed.
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  • 文章类型: Journal Article
    该研究旨在引入一种新颖的成像方法,该方法可产生大覆盖范围,承重,和整个脊柱的3D图像。所提出的系统包括X射线管,一个平板探测器,一个站立的平台。站立平台旋转成像对象,允许从不同角度采集可用于创建3D图像的连续荧光图像。为了增加纵向覆盖范围,我们应用分段扫描模式,其中成像区域分段扫描并缝合。为了解决段之间数据不准确的问题,冗余区域设置在分段图像的边缘,并应用了配准和拼接算法。我们进行了验证实验以评估辐射剂量和图像质量。使用容积CT剂量指数(CTDIvol)评估剂量。对于图像质量评估,我们测量了低对比度和空间分辨率。此外,我们进行了一项由30名青少年特发性脊柱侧凸志愿者组成的临床研究,他们通过我们的方法进行了成像,并根据图像噪声对图像进行主观评估,神器,解剖覆盖,诊断信心,和整体质量。CTDIvol为1.23mGy,4mm时的低对比度分辨率为0.6%,空间分辨率为8lp/cm。临床图像质量总体良好,所有因素的得分都很高。我们的方法成功地产生了大覆盖范围,承重,和整个脊柱的3D图像,具有高图像质量和低辐射剂量。它显示了各种肌肉骨骼疾病的更广泛临床应用的潜力。
    The study aimed to introduce a novel imaging method that generates large-coverage, weight-bearing, and 3D images of the whole spine. The proposed system comprises an X-ray tube, a flat panel detector, and a standing platform. The standing platform rotates the imaged subject, allowing for the acquisition of serial fluoroscopic images from different angles which can be used to create 3D images. To increase the longitudinal coverage, we apply a segmental scanning pattern in which the imaged region is scanned in segments and stitched. To address the issue of data inaccuracy between the segments, redundant areas are set at margins of the segmental images, and registration and stitching algorithms are applied. We conducted validation experiments to evaluate radiation dose and image quality. The dose was evaluated using the volume CT dose index (CTDIvol). For image quality evaluation, we measured the low-contrast and spatial resolution. Additionally, we conducted a clinical study consisting of 30 volunteers with adolescent idiopathic scoliosis who were imaged by our method, and the images were subjectively assessed based on image noise, artifacts, anatomical coverage, diagnostic confidence, and overall quality. The CTDIvol was 1.23 mGy, and the low-contrast resolution was 0.6% at 4 mm and the spatial resolution was 8 lp/cm. The clinical images were generally of good quality, with high scores for all factors evaluated. Our method successfully generates large-coverage, weight-bearing, and 3D images of the whole spine with high image quality and low radiation dose. It shows potential for wider clinical applications for various musculoskeletal conditions.
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  • 文章类型: Journal Article
    背景:这项研究旨在评估视野(FOV)和体素大小对动态导航(DN)辅助的牙髓显微手术(EMS)准确性的影响。
    方法:将9组由180颗牙齿组成的上颌和下颌三维打印颌骨模型分为9组,具有不同的FOV(80×80mm,60×60mm,和40×40毫米)和体素尺寸(0.3毫米,0.16mm,和0.08毫米)。牙髓DN系统用于计划和执行EMS。DN-EMS的精度由平台偏差表示,终点偏差,角度偏差,切除角度,和切除长度偏差。使用SPSS24.0进行统计分析,显著性水平设定为P<0.05。
    结果:平均平台偏差,终点偏差,角度偏差,切除角度,切除长度偏差为0.69±0.31mm,0.93±0.44mm,3.47±1.80°,2.35±1.76°,和0.41±0.29毫米,分别。在9个FOV和体素尺寸组之间没有观察到统计学上显著的准确性差异。
    结论:FOV和体素大小似乎对DN-EMS的准确性没有重要作用。考虑到图像质量和辐射剂量,选择有限的FOV(例如40×40mm和60×60mm)仅覆盖配准设备是合理的,涉及牙齿,和根尖周病变。应根据所需的分辨率和锥形束计算机断层摄影单位来选择体素尺寸。
    BACKGROUND: This study aimed to evaluate the influence of field of view (FOV) and voxel size on the accuracy of dynamic navigation (DN)-assisted endodontic microsurgery (EMS).
    METHODS: Nine sets of maxillary and mandibular 3-dimensional-printed jaw models composed of 180 teeth were divided into 9 groups with different FOVs (80 × 80 mm, 60 × 60 mm, and 40 × 40 mm) and voxel sizes (0.3 mm, 0.16 mm, and 0.08 mm). The endodontic DN system was used to plan and execute the EMS. The accuracy of the DN-EMS was represented by the platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. Statistical analyses were performed using SPSS 24.0, and the significance level was set at P < .05.
    RESULTS: The average platform deviation, end deviation, angular deviation, resection angle, and resection length deviation were 0.69 ± 0.31 mm, 0.93 ± 0.44 mm, 3.47 ± 1.80°, 2.35 ± 1.76°, and 0.41 ± 0.29 mm, respectively. No statistically significant differences in accuracy were observed between the nine FOV and voxel size groups.
    CONCLUSIONS: FOV and voxel size did not appear to play an important role in the accuracy of DN-EMS. Considering the image quality and radiation dose, it is reasonable to select a limited FOV (such as 40 × 40 mm and 60 × 60 mm) to cover only the registration device, involved teeth, and periapical lesion. The voxel size should be selected according to the required resolution and cone-beam computed tomography units.
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  • 文章类型: Journal Article
    在材料科学和生物医学等领域的持续研究需要开发具有大视场(FOV)和深亚波长分辨率的超分辨率成像技术,该技术与荧光和非荧光样品兼容。现有的片上超分辨率方法只专注于荧光或非荧光成像,and,因此,迫切需要一种能够实现两种成像模式的更通用的技术。在这项研究中,为了在单个可扩展的光子芯片上实现标记和无标记的超分辨率成像,介绍了一种基于可调谐虚拟波矢空间频率偏移(TVSFS)原理的通用超分辨率成像方法。利用这个原理,成像分辨率可以比线性光学系统的衍射极限提高三倍以上。这里,衍射单元制作在芯片的表面上,以提供波矢可变的渐逝波照明,在傅立叶空间中实现可调谐的空间频率偏移。使用磷化镓(GaP)芯片,无标记和荧光标记的样品可获得较大的FOV和分辨率为λ/4.7和λ/7.1。凭借其大视野,与不同成像模式的兼容性,和单片集成,所提出的TVSFS芯片可以推进细胞工程等领域,精密工业检验,和化学研究。
    Continued research in fields such as materials science and biomedicine requires the development of a super-resolution imaging technique with a large field of view (FOV) and deep subwavelength resolution that is compatible with both fluorescent and nonfluorescent samples. Existing on-chip super-resolution methods exclusively focus on either fluorescent or nonfluorescent imaging, and, as such, there is an urgent requirement for a more general technique that is capable of both modes of imaging. In this study, to realize labeled and label-free super-resolution imaging on a single scalable photonic chip, a universal super-resolution imaging method based on the tunable virtual-wavevector spatial frequency shift (TVSFS) principle is introduced. Using this principle, imaging resolution can be improved more than threefold over the diffraction limit of a linear optical system. Here, diffractive units are fabricated on the chip\'s surface to provide wavevector-variable evanescent wave illumination, enabling tunable spatial frequency shifts in the Fourier space. A large FOV and resolutions of λ/4.7 and λ/7.1 were achieved for label-free and fluorescently labeled samples using a gallium phosphide (GaP) chip. With its large FOV, compatibility with different imaging modes, and monolithic integration, the proposed TVSFS chip may advance fields such as cell engineering, precision industry inspection, and chemical research.
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  • 文章类型: Journal Article
    This paper investigates a composite optical receiver for an indoor visible light communication (VLC) system. The optical gain, received power, and signal-to-noise ratio (SNR) are considered to be optimized. However, it is difficult to find a balance between them in general design and optimization. We propose the Taguchi and fuzzy logic combination method to improve multiple performance characteristics effectively in the optical receiver. The simulated results indicate that the designed receiver has the characteristics of an optical gain of 10.57, a half field of view (HFOV) of 45°, a received power of 6.4635 dBm, a signal-to-noise ratio (SNR) of 89.8874 dB, and a spot size of 2 mm. The appropriate weights of the three performance characteristics for the inputs of the fuzzy controllers increase the optical gain by 13.601 dB, and the received power and SNR by 11.097 dB and 0.373 dB, respectively. Therefore, the optical receiver optimally designed by the Taguchi and fuzzy logic methods can significantly meet the requirements of an indoor VLC system.
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