Christian M. Jennings, Andrew C. Markel, Mari J. E. Domingo, Kristin S. Miller, Carolyn L. Bayer, and Sapun H. Parekh
Pelvic organ prolapse (POP) is a gynecological disorder described by the descent of superior pelvic organs into or out of the vagina as a consequence of disrupted muscles and tissue. A thorough understanding of the etiology of POP is limited by the availability of clinically relevant samples, restricting longitudinal POP studies on soft-tissue biomechanics and structure to POP-induced models such as fibulin-5 knockout (FBLN5-/-) mice. Despite being a principal constituent in the extracellular matrix, little is known about structural perturbations to collagen networks in the FBLN5-/- mouse cervix. We identify significantly different collagen network populations in normal and prolapsed cervical cross-sections using two label-free, nonlinear microscopy techniques. Collagen in the prolapsed mouse cervix tends to be more isotropic, and displays reduced alignment persistence via 2-D Fourier transform analysis of images acquired using second harmonic generation microscopy. Furthermore, coherent Raman hyperspectral imaging revealed elevated disorder in the secondary structure of collagen in prolapsed tissues. Our results underscore the need for in situ multimodal monitoring of collagen organization to improve POP predictive capabilities.
盆腔器官脱垂（POP）是一种妇科疾病，其特征是由于肌肉和组织的破坏导致盆腔上部器官脱入或脱出阴道。对 POP 病因的透彻了解受限于临床相关样本的可用性，有关软组织生物力学和结构的纵向 POP 研究仅限于 POP 诱导模型，如纤维蛋白 5 基因敲除（FBLN5-/-）小鼠。尽管胶原蛋白是细胞外基质的主要成分，但人们对 FBLN5-/- 小鼠宫颈中胶原蛋白网络的结构扰动知之甚少。我们使用两种无标记、非线性显微镜技术在正常和脱垂的宫颈横截面上发现了明显不同的胶原网络群体。通过对使用二次谐波发生显微镜获取的图像进行二维傅立叶变换分析，发现脱垂小鼠宫颈中的胶原蛋白更趋向于各向同性，并且排列持续性降低。此外，相干拉曼高光谱成像显示，脱垂组织中胶原蛋白二级结构的紊乱程度增加。我们的研究结果强调了对胶原组织进行原位多模态监测以提高持久性有机污染物预测能力的必要性。
{"title":"Collagen organization and structure in FBLN5-/- mice using label-free microscopy: implications for pelvic organ prolapse","authors":"Christian M. Jennings, Andrew C. Markel, Mari J. E. Domingo, Kristin S. Miller, Carolyn L. Bayer, and Sapun H. Parekh","doi":"10.1364/boe.518976","DOIUrl":"https://doi.org/10.1364/boe.518976","url":null,"abstract":"Pelvic organ prolapse (POP) is a gynecological disorder described by the descent of superior pelvic organs into or out of the vagina as a consequence of disrupted muscles and tissue. A thorough understanding of the etiology of POP is limited by the availability of clinically relevant samples, restricting longitudinal POP studies on soft-tissue biomechanics and structure to POP-induced models such as fibulin-5 knockout (<i>FBLN5<sup>-/-</sup></i>) mice. Despite being a principal constituent in the extracellular matrix, little is known about structural perturbations to collagen networks in the <i>FBLN5<sup>-/-</sup></i> mouse cervix. We identify significantly different collagen network populations in normal and prolapsed cervical cross-sections using two label-free, nonlinear microscopy techniques. Collagen in the prolapsed mouse cervix tends to be more isotropic, and displays reduced alignment persistence via 2-D Fourier transform analysis of images acquired using second harmonic generation microscopy. Furthermore, coherent Raman hyperspectral imaging revealed elevated disorder in the secondary structure of collagen in prolapsed tissues. Our results underscore the need for <i>in situ</i> multimodal monitoring of collagen organization to improve POP predictive capabilities.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the effectiveness of a computer-aided diagnosis system, the quality of whole-slide image (WSI) is the foundation, and a useful autofocus method is an important part of ensuring the quality of WSI. The existing autofocus methods need to balance focusing speed and focusing accuracy, and need to be optimized separately for different samples or scenes. In this paper, a robust autofocus method based on fiber bundle illumination and image normalization analysis is proposed. For various application scenes, it meets the requirements of autofocusing through active illumination, such as bright field imaging and fluorescence imaging. For different structures on samples, it ensures the autofocusing accuracy through image analysis. The experimental results imply that the autofocusing method in this paper can effectively track the change of the distance from the sample to the focal plane and significantly improve the WSI quality.
对于计算机辅助诊断系统的有效性而言，整幅图像（WSI）的质量是基础，而实用的自动对焦方法是确保 WSI 质量的重要组成部分。现有的自动对焦方法需要兼顾对焦速度和对焦精度，并需要针对不同的样本或场景分别进行优化。本文提出了一种基于光纤束照明和图像归一化分析的稳健自动对焦方法。对于不同的应用场景，它能通过主动照明满足自动对焦的要求，如明场成像和荧光成像。针对样品上的不同结构，通过图像分析确保自动对焦的准确性。实验结果表明，本文中的自动对焦方法能有效跟踪样品到焦平面距离的变化，显著提高 WSI 质量。
{"title":"Robust autofocus method based on patterned active illumination and image cross-correlation analysis","authors":"Caiwei Li, Kehan Liu, Xiaoguang Guo, Yinghao Xiao, Yingjun Zhang, and Zhen-Li Huang","doi":"10.1364/boe.520514","DOIUrl":"https://doi.org/10.1364/boe.520514","url":null,"abstract":"For the effectiveness of a computer-aided diagnosis system, the quality of whole-slide image (WSI) is the foundation, and a useful autofocus method is an important part of ensuring the quality of WSI. The existing autofocus methods need to balance focusing speed and focusing accuracy, and need to be optimized separately for different samples or scenes. In this paper, a robust autofocus method based on fiber bundle illumination and image normalization analysis is proposed. For various application scenes, it meets the requirements of autofocusing through active illumination, such as bright field imaging and fluorescence imaging. For different structures on samples, it ensures the autofocusing accuracy through image analysis. The experimental results imply that the autofocusing method in this paper can effectively track the change of the distance from the sample to the focal plane and significantly improve the WSI quality.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feng Li, Zetao Huang, Lu Zhou, Yuyang Chen, Shiqing Tang, Pengchao Ding, Haixia Peng, and Yimin Chu
Automatic and precise polyp segmentation in colonoscopy images is highly valuable for diagnosis at an early stage and surgery of colorectal cancer. Nevertheless, it still posed a major challenge due to variations in the size and intricate morphological characteristics of polyps coupled with the indistinct demarcation between polyps and mucosas. To alleviate these challenges, we proposed an improved dual-aggregation polyp segmentation network, dubbed Dua-PSNet, for automatic and accurate full-size polyp prediction by combining both the transformer branch and a fully convolutional network (FCN) branch in a parallel style. Concretely, in the transformer branch, we adopted the B3 variant of pyramid vision transformer v2 (PVTv2-B3) as an image encoder for capturing multi-scale global features and modeling long-distant interdependencies between them whilst designing an innovative multi-stage feature aggregation decoder (MFAD) to highlight critical local feature details and effectively integrate them into global features. In the decoder, the adaptive feature aggregation (AFA) block was constructed for fusing high-level feature representations of different scales generated by the PVTv2-B3 encoder in a stepwise adaptive manner for refining global semantic information, while the ResidualBlock module was devised to mine detailed boundary cues disguised in low-level features. With the assistance of the selective global-to-local fusion head (SGLFH) module, the resulting boundary details were aggregated selectively with these global semantic features, strengthening these hierarchical features to cope with scale variations of polyps. The FCN branch embedded in the designed ResidualBlock module was used to encourage extraction of highly merged fine features to match the outputs of the Transformer branch into full-size segmentation maps. In this way, both branches were reciprocally influenced and complemented to enhance the discrimination capability of polyp features and enable a more accurate prediction of a full-size segmentation map. Extensive experiments on five challenging polyp segmentation benchmarks demonstrated that the proposed Dua-PSNet owned powerful learning and generalization ability and advanced the state-of-the-art segmentation performance among existing cutting-edge methods. These excellent results showed our Dua-PSNet had great potential to be a promising solution for practical polyp segmentation tasks in which wide variations of data typically occurred.
{"title":"Improved dual-aggregation polyp segmentation network combining a pyramid vision transformer with a fully convolutional network","authors":"Feng Li, Zetao Huang, Lu Zhou, Yuyang Chen, Shiqing Tang, Pengchao Ding, Haixia Peng, and Yimin Chu","doi":"10.1364/boe.510908","DOIUrl":"https://doi.org/10.1364/boe.510908","url":null,"abstract":"Automatic and precise polyp segmentation in colonoscopy images is highly valuable for diagnosis at an early stage and surgery of colorectal cancer. Nevertheless, it still posed a major challenge due to variations in the size and intricate morphological characteristics of polyps coupled with the indistinct demarcation between polyps and mucosas. To alleviate these challenges, we proposed an improved dual-aggregation polyp segmentation network, dubbed Dua-PSNet, for automatic and accurate full-size polyp prediction by combining both the transformer branch and a fully convolutional network (FCN) branch in a parallel style. Concretely, in the transformer branch, we adopted the B3 variant of pyramid vision transformer v2 (PVTv2-B3) as an image encoder for capturing multi-scale global features and modeling long-distant interdependencies between them whilst designing an innovative multi-stage feature aggregation decoder (MFAD) to highlight critical local feature details and effectively integrate them into global features. In the decoder, the adaptive feature aggregation (AFA) block was constructed for fusing high-level feature representations of different scales generated by the PVTv2-B3 encoder in a stepwise adaptive manner for refining global semantic information, while the ResidualBlock module was devised to mine detailed boundary cues disguised in low-level features. With the assistance of the selective global-to-local fusion head (SGLFH) module, the resulting boundary details were aggregated selectively with these global semantic features, strengthening these hierarchical features to cope with scale variations of polyps. The FCN branch embedded in the designed ResidualBlock module was used to encourage extraction of highly merged fine features to match the outputs of the Transformer branch into full-size segmentation maps. In this way, both branches were reciprocally influenced and complemented to enhance the discrimination capability of polyp features and enable a more accurate prediction of a full-size segmentation map. Extensive experiments on five challenging polyp segmentation benchmarks demonstrated that the proposed Dua-PSNet owned powerful learning and generalization ability and advanced the state-of-the-art segmentation performance among existing cutting-edge methods. These excellent results showed our Dua-PSNet had great potential to be a promising solution for practical polyp segmentation tasks in which wide variations of data typically occurred.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zewen Yang, Lu Zhang, Tong Liu, Huijun Wang, Zhiyuan Tang, Hong Zhao, Li Yuan, Zhenxi Zhang, and Xiaolong Liu
Optical diffraction tomography (ODT) is a powerful label-free measurement tool that can quantitatively image the three-dimensional (3D) refractive index (RI) distribution of samples. However, the inherent "missing cone problem," limited illumination angles, and dependence on intensity-only measurements in a simplified imaging setup can all lead to insufficient information mapping in the Fourier domain, affecting 3D reconstruction results. In this paper, we propose the alternating projection combined with the fast gradient projection (FGP-AP) method to compensate for the above problem, which effectively reconstructs the 3D RI distribution of samples using intensity-only images captured from LED array microscopy. The FGP-AP method employs the alternating projection (AP) algorithm for gradient descent and the fast gradient projection (FGP) algorithm for regularization constraints. This approach is equivalent to incorporating prior knowledge of sample non-negativity and smoothness into the 3D reconstruction process. Simulations demonstrate that the FGP-AP method improves reconstruction quality compared to the original AP method, particularly in the presence of noise. Experimental results, obtained from mouse kidney cells and label-free blood cells, further affirm the superior 3D imaging efficacy of the FGP-AP method.
光学衍射层析成像（ODT）是一种强大的无标记测量工具，可对样品的三维折射率（RI）分布进行定量成像。然而，在简化的成像装置中，固有的 "缺失锥问题"、有限的照明角度以及对纯强度测量的依赖都会导致傅里叶域的信息映射不足，从而影响三维重建结果。在本文中，我们提出了交替投影结合快速梯度投影（FGP-AP）方法来弥补上述问题，该方法能利用 LED 阵列显微镜捕获的纯强度图像有效地重建样品的三维 RI 分布。FGP-AP 方法采用交替投影（AP）算法进行梯度下降，并采用快速梯度投影（FGP）算法进行正则化约束。这种方法相当于将样本非负性和平滑性的先验知识纳入三维重建过程。模拟结果表明，与原始 AP 方法相比，FGP-AP 方法提高了重建质量，尤其是在存在噪声的情况下。小鼠肾脏细胞和无标记血细胞的实验结果进一步证实了 FGP-AP 方法卓越的三维成像效果。
{"title":"Alternating projection combined with fast gradient projection (FGP-AP) method for intensity-only measurement optical diffraction tomography in LED array microscopy","authors":"Zewen Yang, Lu Zhang, Tong Liu, Huijun Wang, Zhiyuan Tang, Hong Zhao, Li Yuan, Zhenxi Zhang, and Xiaolong Liu","doi":"10.1364/boe.518955","DOIUrl":"https://doi.org/10.1364/boe.518955","url":null,"abstract":"Optical diffraction tomography (ODT) is a powerful label-free measurement tool that can quantitatively image the three-dimensional (3D) refractive index (RI) distribution of samples. However, the inherent \"missing cone problem,\" limited illumination angles, and dependence on intensity-only measurements in a simplified imaging setup can all lead to insufficient information mapping in the Fourier domain, affecting 3D reconstruction results. In this paper, we propose the alternating projection combined with the fast gradient projection (FGP-AP) method to compensate for the above problem, which effectively reconstructs the 3D RI distribution of samples using intensity-only images captured from LED array microscopy. The FGP-AP method employs the alternating projection (AP) algorithm for gradient descent and the fast gradient projection (FGP) algorithm for regularization constraints. This approach is equivalent to incorporating prior knowledge of sample non-negativity and smoothness into the 3D reconstruction process. Simulations demonstrate that the FGP-AP method improves reconstruction quality compared to the original AP method, particularly in the presence of noise. Experimental results, obtained from mouse kidney cells and label-free blood cells, further affirm the superior 3D imaging efficacy of the FGP-AP method.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140198118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alessandro Bossi, Leonardo Bianchi, Paola Saccomandi, and Antonio Pifferi
Thermal therapies treat tumors by means of heat, greatly reducing pain, post-operation complications, and cost as compared to traditional methods. Yet, effective tools to avoid under- or over-treatment are mostly needed, to guide surgeons in laparoscopic interventions. In this work, we investigated the temperature-dependent optical signatures of ex-vivo calf brain, lung, and heart tissues based on the reduced scattering and absorption coefficients in the near-infrared spectral range (657 to 1107 nm). These spectra were measured by time domain diffuse optics, applying a step-like spatially homogeneous thermal treatment at 43 °C, 60 °C, and 80 °C. We found three main increases in scattering spectra, possibly due to the denaturation of collagen, myosin, and the proteins' secondary structure. After 75 °C, we found the rise of two new peaks at 770 and 830 nm in the absorption spectra due to the formation of a new chromophore, possibly related to hemoglobin or myoglobin. This research marks a significant step forward in controlling thermal therapies with diffuse optical techniques by identifying several key markers of thermal damage. This could enhance the ability to monitor and adjust treatment in real-time, promising improved outcomes in tumor therapy.
{"title":"Optical signatures of thermal damage on ex-vivo brain, lung and heart tissues using time-domain diffuse optical spectroscopy","authors":"Alessandro Bossi, Leonardo Bianchi, Paola Saccomandi, and Antonio Pifferi","doi":"10.1364/boe.517376","DOIUrl":"https://doi.org/10.1364/boe.517376","url":null,"abstract":"Thermal therapies treat tumors by means of heat, greatly reducing pain, post-operation complications, and cost as compared to traditional methods. Yet, effective tools to avoid under- or over-treatment are mostly needed, to guide surgeons in laparoscopic interventions. In this work, we investigated the temperature-dependent optical signatures of ex-vivo calf brain, lung, and heart tissues based on the reduced scattering and absorption coefficients in the near-infrared spectral range (657 to 1107 nm). These spectra were measured by time domain diffuse optics, applying a step-like spatially homogeneous thermal treatment at 43 °C, 60 °C, and 80 °C. We found three main increases in scattering spectra, possibly due to the denaturation of collagen, myosin, and the proteins' secondary structure. After 75 °C, we found the rise of two new peaks at 770 and 830 nm in the absorption spectra due to the formation of a new chromophore, possibly related to hemoglobin or myoglobin. This research marks a significant step forward in controlling thermal therapies with diffuse optical techniques by identifying several key markers of thermal damage. This could enhance the ability to monitor and adjust treatment in real-time, promising improved outcomes in tumor therapy.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140165279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Comprehensive visualization and accurate extraction of tumor vasculature are essential to study the nature of glioma. Nowadays, tissue clearing technology enables 3D visualization of human glioma vasculature at micron resolution, but current vessel extraction schemes cannot well cope with the extraction of complex tumor vessels with high disruption and irregularity under realistic conditions. Here, we developed a framework, FineVess, based on deep learning to automatically extract glioma vessels in confocal microscope images of cleared human tumor tissues. In the framework, a customized deep learning network, named 3D ResCBAM nnU-Net, was designed to segment the vessels, and a novel pipeline based on preprocessing and post-processing was developed to refine the segmentation results automatically. On the basis of its application to a practical dataset, we showed that the FineVess enabled extraction of variable and incomplete vessels with high accuracy in challenging 3D images, better than other traditional and state-of-the-art schemes. For the extracted vessels, we calculated vascular morphological features including fractal dimension and vascular wall integrity of different tumor grades, and verified the vascular heterogeneity through quantitative analysis.
全面观察和准确提取肿瘤血管对研究胶质瘤的本质至关重要。目前，组织清除技术可以实现微米级分辨率的人类胶质瘤血管三维可视化，但现有的血管提取方案无法很好地应对现实条件下高度破坏和不规则的复杂肿瘤血管的提取。在此，我们开发了一个基于深度学习的框架 FineVess，用于自动提取共聚焦显微镜图像中已清除的人类肿瘤组织中的胶质瘤血管。在该框架中，我们设计了一个定制的深度学习网络（名为 3D ResCBAM nnU-Net）来分割血管，并开发了一个基于预处理和后处理的新管道来自动完善分割结果。通过对实际数据集的应用，我们发现 FineVess 能够在具有挑战性的三维图像中高精度地提取可变和不完整的血管，其效果优于其他传统和最先进的方案。对于提取的血管，我们计算了不同肿瘤等级的血管形态特征，包括分形维度和血管壁完整性，并通过定量分析验证了血管的异质性。
{"title":"Deep learning-based vessel extraction in 3D confocal microscope images of cleared human glioma tissues","authors":"Xiaodu Yang, Dian He, Yu Li, Chenyang Li, Xinyue Wang, Xingzheng Zhu, Haitao Sun, and Yingying Xu","doi":"10.1364/boe.516541","DOIUrl":"https://doi.org/10.1364/boe.516541","url":null,"abstract":"Comprehensive visualization and accurate extraction of tumor vasculature are essential to study the nature of glioma. Nowadays, tissue clearing technology enables 3D visualization of human glioma vasculature at micron resolution, but current vessel extraction schemes cannot well cope with the extraction of complex tumor vessels with high disruption and irregularity under realistic conditions. Here, we developed a framework, FineVess, based on deep learning to automatically extract glioma vessels in confocal microscope images of cleared human tumor tissues. In the framework, a customized deep learning network, named 3D ResCBAM nnU-Net, was designed to segment the vessels, and a novel pipeline based on preprocessing and post-processing was developed to refine the segmentation results automatically. On the basis of its application to a practical dataset, we showed that the FineVess enabled extraction of variable and incomplete vessels with high accuracy in challenging 3D images, better than other traditional and state-of-the-art schemes. For the extracted vessels, we calculated vascular morphological features including fractal dimension and vascular wall integrity of different tumor grades, and verified the vascular heterogeneity through quantitative analysis.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140165513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Augusto Arias, Diego Montagud-Martinez, and Pablo Artal
Both cataracts and age-related macular degeneration (AMD) may occur with aging and are often developed simultaneously. We performed a study to better characterize the impact of induced scatter on the quality of vision in the near periphery, a region where individuals with AMD typically maintain their functional vision. We used an optical instrument as a cataract simulator based on projecting at the eye’s pupil plane phase masks with controlled spatial properties generated with a spatial light modulator. The phase wavefronts were designed to accurately replicate the angular distribution of light intensity in the retina found in cataractous eyes with different severities. The induced amount of scatter ranged from values of straylight (S) from 10 to 85 degree2/sr, which corresponds from normal aging eye to advanced cataract stages. Mesopic visual acuity (VA) and contrast sensitivity (CS) at 3 cycles per degree were measured at the fovea and two retinal eccentricities (5 and 10 degrees in nasal visual field). We observed a consistent linear decline in VA (expressed in LogMAR) as the amount of induced scatter (quantified by the straylight parameter S) increased, both at the fovea and in the periphery. The effect of induced scattering on mesopic VA and CS at the fovea and the near periphery was evaluated. We found a relatively lower impact of scatter in the near periphery. This may explain the modest improvement in vision often found after cataract surgery in patients with AMD.
白内障和老年性黄斑变性（AMD）都可能随着年龄的增长而发生，而且通常是同时发生的。我们进行了一项研究，以更好地描述诱导散射对近周视力质量的影响，AMD 患者通常在这一区域保持功能性视力。我们使用了一种光学仪器作为白内障模拟器，其原理是在眼睛的瞳孔平面上投射由空间光调制器生成的具有可控空间特性的相位面罩。相位波面的设计旨在精确复制不同严重程度的白内障患者视网膜上光强度的角度分布。诱导的散射量从 10 到 85 度/秒r 的杂散光 (S) 值不等，对应于从正常老化眼到晚期白内障阶段。在眼窝和两个视网膜偏心处（鼻视野 5 度和 10 度）测量了每度 3 个周期的中视视力（VA）和对比敏感度（CS）。我们观察到，随着诱导散射量（用杂散光参数 S 量化）的增加，VA（用 LogMAR 表示）呈一致的线性下降趋势，在眼窝和周边均是如此。我们评估了诱导散射对眼窝和近周边中视 VA 和 CS 的影响。我们发现散射对近周的影响相对较小。这可能是白内障手术后视力改善不大的原因。
{"title":"Effects of intraocular scatter on near peripheral vision","authors":"Augusto Arias, Diego Montagud-Martinez, and Pablo Artal","doi":"10.1364/boe.523715","DOIUrl":"https://doi.org/10.1364/boe.523715","url":null,"abstract":"Both cataracts and age-related macular degeneration (AMD) may occur with aging and are often developed simultaneously. We performed a study to better characterize the impact of induced scatter on the quality of vision in the near periphery, a region where individuals with AMD typically maintain their functional vision. We used an optical instrument as a cataract simulator based on projecting at the eye’s pupil plane phase masks with controlled spatial properties generated with a spatial light modulator. The phase wavefronts were designed to accurately replicate the angular distribution of light intensity in the retina found in cataractous eyes with different severities. The induced amount of scatter ranged from values of straylight (S) from 10 to 85 degree<sup>2</sup>/sr, which corresponds from normal aging eye to advanced cataract stages. Mesopic visual acuity (VA) and contrast sensitivity (CS) at 3 cycles per degree were measured at the fovea and two retinal eccentricities (5 and 10 degrees in nasal visual field). We observed a consistent linear decline in VA (expressed in LogMAR) as the amount of induced scatter (quantified by the straylight parameter S) increased, both at the fovea and in the periphery. The effect of induced scattering on mesopic VA and CS at the fovea and the near periphery was evaluated. We found a relatively lower impact of scatter in the near periphery. This may explain the modest improvement in vision often found after cataract surgery in patients with AMD.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140165880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tianqi Fang, Huan Han, Jingyu Sun, Aleese Mukhamedjanova, and Shang Wang
The mammalian oviduct (or fallopian tube) is a tubular organ hosting reproductive events leading to pregnancy. Dynamic 3D imaging of the mouse oviduct with optical coherence tomography (OCT) has recently emerged as a promising approach to study the hidden processes vital to elucidate the role of oviduct in mammalian reproduction and reproductive disorders. In particular, with an intravital window, in vivo OCT imaging is a powerful solution to studying how the oviduct transports preimplantation embryos towards the uterus for pregnancy, a long-standing question that is critical for uncovering the functional cause of tubal ectopic pregnancy. However, simultaneously tracking embryo movement and acquiring large-field-of-view images of oviduct activity in 3D has been challenging due to the generally limited volumetric imaging rate of OCT. A lack of OCT-based 3D velocimetry method for large, sparse particles acts as a technical hurdle for analyzing the mechanistic process of the embryo transport. Here, we report a new particle streak velocimetry method to address this hurdle. The method relies on the 3D streak of a moving particle formed during the acquisition of a single OCT volume, where double B-scans are acquired at each B-scan location to resolve ambiguity in assessing the movement of particle. We validated this method with the gold-standard, direct volumetric particle tracking in a flow phantom, and we demonstrated its in vivo applications for simultaneous velocimetry of embryos and imaging of oviduct. This work sets the stage for quantitative understanding of the oviduct transport function in vivo, and the method fills in a gap in OCT-based velocimetry, providing the potential to enable new applications in 3D flow imaging.
哺乳动物的输卵管（或输卵管）是一个管状器官，承载着导致怀孕的生殖过程。最近，利用光学相干断层扫描（OCT）对小鼠输卵管进行动态三维成像已成为一种很有前途的方法，可用于研究对阐明输卵管在哺乳动物生殖和生殖疾病中的作用至关重要的隐藏过程。特别是，利用体内视窗，活体 OCT 成像是研究输卵管如何将着床前胚胎运送到子宫进行妊娠的有力解决方案，这是一个长期存在的问题，对于揭示输卵管异位妊娠的功能性原因至关重要。然而，由于 OCT 的容积成像率普遍有限，同时跟踪胚胎运动和获取输卵管活动的三维大视场图像一直是个难题。缺乏基于 OCT 的大型稀疏颗粒三维测速方法成为分析胚胎运输机理过程的技术障碍。在此，我们报告了一种新的颗粒条纹测速方法来解决这一障碍。该方法依赖于在采集单个 OCT 容积时形成的运动粒子的三维条纹，在每个 B 扫描位置采集双 B 扫描，以解决评估粒子运动时的模糊性。我们用流体模型中的黄金标准--直接体积颗粒跟踪法验证了这种方法，并展示了它在胚胎测速和输卵管成像中的体内应用。这项工作为定量了解输卵管在体内的传输功能奠定了基础，该方法填补了基于 OCT 测速仪的空白，为三维流动成像的新应用提供了可能。
{"title":"Three-dimensional particle streak velocimetry based on optical coherence tomography for assessing preimplantation embryo movement in mouse oviduct in vivo","authors":"Tianqi Fang, Huan Han, Jingyu Sun, Aleese Mukhamedjanova, and Shang Wang","doi":"10.1364/boe.519595","DOIUrl":"https://doi.org/10.1364/boe.519595","url":null,"abstract":"The mammalian oviduct (or fallopian tube) is a tubular organ hosting reproductive events leading to pregnancy. Dynamic 3D imaging of the mouse oviduct with optical coherence tomography (OCT) has recently emerged as a promising approach to study the hidden processes vital to elucidate the role of oviduct in mammalian reproduction and reproductive disorders. In particular, with an intravital window, <i>in vivo</i> OCT imaging is a powerful solution to studying how the oviduct transports preimplantation embryos towards the uterus for pregnancy, a long-standing question that is critical for uncovering the functional cause of tubal ectopic pregnancy. However, simultaneously tracking embryo movement and acquiring large-field-of-view images of oviduct activity in 3D has been challenging due to the generally limited volumetric imaging rate of OCT. A lack of OCT-based 3D velocimetry method for large, sparse particles acts as a technical hurdle for analyzing the mechanistic process of the embryo transport. Here, we report a new particle streak velocimetry method to address this hurdle. The method relies on the 3D streak of a moving particle formed during the acquisition of a single OCT volume, where double B-scans are acquired at each B-scan location to resolve ambiguity in assessing the movement of particle. We validated this method with the gold-standard, direct volumetric particle tracking in a flow phantom, and we demonstrated its <i>in vivo</i> applications for simultaneous velocimetry of embryos and imaging of oviduct. This work sets the stage for quantitative understanding of the oviduct transport function <i>in vivo</i>, and the method fills in a gap in OCT-based velocimetry, providing the potential to enable new applications in 3D flow imaging.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140165505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xuesong Han, Xuezhi Yang, Shuai Fang, Yawei Chen, Qin Chen, Longwei Li, and RenCheng Song
In recent years, imaging photoplethysmograph (iPPG) pulse signals have been widely used in the research of non-contact blood pressure (BP) estimation, in which BP estimation based on pulse features is the main research direction. Pulse features are directly related to the shape of pulse signals while iPPG pulse signals are easily disturbed during the extraction process. To mitigate the impact of pulse feature distortion on BP estimation, it is necessary to eliminate interference while retaining valuable shape details in the iPPG pulse signal. Contact photoplethysmograph (cPPG) pulse signals measured at rest can be considered as the undisturbed reference signal. Transforming the iPPG pulse signal to the corresponding cPPG pulse signal is a method to ensure the effectiveness of shape details. However, achieving the required shape accuracy through direct transformation from iPPG to the corresponding cPPG pulse signals is challenging. We propose a method to mitigate this challenge by replacing the reference signal with an average cardiac cycle (ACC) signal, which can approximately represent the shape information of all cardiac cycles in a short time. A neural network using multi-scale convolution and self-attention mechanisms is developed for this transformation. Our method demonstrates a significant improvement in the maximal information coefficient (MIC) between pulse features and BP values, indicating a stronger correlation. Moreover, pulse signals transformed by our method exhibit enhanced performance in BP estimation using different model types. Experiments are conducted on a real-world database with 491 subjects in the hospital, averaging 60 years of age.
{"title":"Preserving shape details of pulse signals for video-based blood pressure estimation","authors":"Xuesong Han, Xuezhi Yang, Shuai Fang, Yawei Chen, Qin Chen, Longwei Li, and RenCheng Song","doi":"10.1364/boe.516388","DOIUrl":"https://doi.org/10.1364/boe.516388","url":null,"abstract":"In recent years, imaging photoplethysmograph (iPPG) pulse signals have been widely used in the research of non-contact blood pressure (BP) estimation, in which BP estimation based on pulse features is the main research direction. Pulse features are directly related to the shape of pulse signals while iPPG pulse signals are easily disturbed during the extraction process. To mitigate the impact of pulse feature distortion on BP estimation, it is necessary to eliminate interference while retaining valuable shape details in the iPPG pulse signal. Contact photoplethysmograph (cPPG) pulse signals measured at rest can be considered as the undisturbed reference signal. Transforming the iPPG pulse signal to the corresponding cPPG pulse signal is a method to ensure the effectiveness of shape details. However, achieving the required shape accuracy through direct transformation from iPPG to the corresponding cPPG pulse signals is challenging. We propose a method to mitigate this challenge by replacing the reference signal with an average cardiac cycle (ACC) signal, which can approximately represent the shape information of all cardiac cycles in a short time. A neural network using multi-scale convolution and self-attention mechanisms is developed for this transformation. Our method demonstrates a significant improvement in the maximal information coefficient (MIC) between pulse features and BP values, indicating a stronger correlation. Moreover, pulse signals transformed by our method exhibit enhanced performance in BP estimation using different model types. Experiments are conducted on a real-world database with 491 subjects in the hospital, averaging 60 years of age.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A multi-function sensor based on an all-dielectric metastructure for temperature and refractive index sensing simultaneously is designed and analyzed in this paper. The structure is composed of a periodic array of silicon dimers placed on the silicon dioxide substrate. By breaking the symmetry of the structure, the ideal bound states in the continuum can be converted to the quasi-bound states in the continuum, and three Fano resonances are excited in the near-infrared wavelength. Combining with the electromagnetic field distributions, the resonant modes of three Fano resonances are analyzed as magnetic dipole, magnetic toroidal dipole, and electric toroidal dipole, respectively. The proposed sensor exhibits an impressive maximal Q-factor of 9352, with a modulation depth approaching 100%. Our investigation into temperature and refractive index sensing properties reveals a maximum temperature sensitivity of 60 pm/K. Regarding refractive index sensing, the sensitivity and figure of merit are determined to be 279.5 nm/RIU and 2055.1 RIU-1, respectively. These findings underscore the potential of the all-dielectric metastructure for simultaneous multi-parameter measurements. The sensor's versatility suggests promising applications in biological and chemical sensing.
{"title":"Multi-function sensing applications based on high Q-factor multi-Fano resonances in an all-dielectric metastructure","authors":"Shuangshuang Cao, Xinye Fan, Wenjing Fang, Mengcheng Du, Qinghe Sun, Huijuan Niu, Chuanchuan Li, Xin Wei, Chenglin Bai, Jifang Tao, Mingxin Li, Baoxi Chen, and Santosh Kumar","doi":"10.1364/boe.518910","DOIUrl":"https://doi.org/10.1364/boe.518910","url":null,"abstract":"A multi-function sensor based on an all-dielectric metastructure for temperature and refractive index sensing simultaneously is designed and analyzed in this paper. The structure is composed of a periodic array of silicon dimers placed on the silicon dioxide substrate. By breaking the symmetry of the structure, the ideal bound states in the continuum can be converted to the quasi-bound states in the continuum, and three Fano resonances are excited in the near-infrared wavelength. Combining with the electromagnetic field distributions, the resonant modes of three Fano resonances are analyzed as magnetic dipole, magnetic toroidal dipole, and electric toroidal dipole, respectively. The proposed sensor exhibits an impressive maximal Q-factor of 9352, with a modulation depth approaching 100%. Our investigation into temperature and refractive index sensing properties reveals a maximum temperature sensitivity of 60 pm/K. Regarding refractive index sensing, the sensitivity and figure of merit are determined to be 279.5 nm/RIU and 2055.1 RIU<sup>-1</sup>, respectively. These findings underscore the potential of the all-dielectric metastructure for simultaneous multi-parameter measurements. The sensor's versatility suggests promising applications in biological and chemical sensing.","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：