{"title":"Quantifying uncertainty in phasor-based time-domain fluorescence lifetime imaging microscopy.","authors":"Qinyi Chen, Jongchan Park, Shuqi Mu, Liang Gao","doi":"10.1364/BOE.565990","DOIUrl":"10.1364/BOE.565990","url":null,"abstract":"<p><p>The phasor approach to time-domain fluorescence lifetime imaging microscopy (FLIM) offers a powerful, fit-free method for analyzing complex fluorescence decay signals. However, its quantitative accuracy is fundamentally limited by noise-particularly photon shot noise-which introduces variability and deviations in lifetime estimation and fluorophore unmixing. In this study, we present a theoretical uncertainty model for phasor-based time-domain FLIM that analytically captures the propagation of shot noise and quantifies its impact on phasor coordinates and fluorophore weight estimation. We validate the model using Monte Carlo simulations and experimental data acquired from standard fluorescent dyes and biological tissue samples. Our model improves the overall reliability and efficiency of phasor-based time-domain FLIM, particularly in photon-limited imaging applications.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3116-3127"},"PeriodicalIF":3.2,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ultra-fast line-field swept source scanning optical coherence elastography.","authors":"Cheng Lu, Jianli Ren, Xikai Wei, Kexin Shen, Xingyu Zhou, Qianfang Huang, Meixiao Shen, Dexi Zhu","doi":"10.1364/BOE.566466","DOIUrl":"10.1364/BOE.566466","url":null,"abstract":"<p><p>The drawbacks of repeated excitations and long imaging time in wave-based optical coherence elastography limited its application in ophthalmology. In this study, we put forward a swept source scanning optical coherence elastography (SSS-OCE) system based on the wavelength-dependence scanning technique. A dispersive element was employed to achieve ultra-fast line scanning from swept light source. Through a series of experiments on agar phantoms with varying concentrations, in situ porcine corneas under different intraocular pressures, and human eyes in vivo, we have demonstrated that SSS-OCE has the capability to rapidly evaluate the elasticity of ocular tissues in vivo with single excitation and offers the advantages of a simple structure and short measurement time.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3105-3115"},"PeriodicalIF":3.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339313/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan Casado-Moreno, Belen Masia, Nanji Lu, Lele Cui, Alejandra Consejo
{"title":"Deep learning-based keratoconus detection from Scheimpflug images.","authors":"Juan Casado-Moreno, Belen Masia, Nanji Lu, Lele Cui, Alejandra Consejo","doi":"10.1364/BOE.559663","DOIUrl":"10.1364/BOE.559663","url":null,"abstract":"<p><p>This study evaluates the effectiveness of deep learning techniques applied to raw Scheimpflug corneal images for keratoconus detection, with a particular focus on forme fruste (FF) keratoconus, which refers to preclinical cases. Using an original dataset of 22,750 images from 910 eyes, a deep learning model based on transfer learning with a pre-trained VGG16 architecture was trained, incorporating specific preprocessing steps and data augmentation strategies. The proposed approach achieved an overall accuracy of 90.70%, with a sensitivity of 80.57%, and a specificity of 80.56% for FF keratoconus classification, and an AUC of 0.89. For clinical keratoconus, the model demonstrated a sensitivity of 93.28%, a specificity of 99.40%, and an AUC of 1.00. These findings highlight the potential of leveraging raw Scheimpflug images in deep learning-based keratoconus detection, particularly for identifying early-stage structural changes that may not be apparent in conventional topographic assessments.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3047-3060"},"PeriodicalIF":3.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339315/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental and numerical investigation of wavelength and resolution dependency of dynamic optical coherence tomography signals.","authors":"Shumpei Fujimura, Ibrahim Abd El-Sadek, Rion Morishita, Shuichi Makita, Atsuko Furukawa, Pradipta Mukherjee, Yiheng Lim, Lida Zhu, Yunake Feng, Thitiya Seesan, Satoshi Matsusaka, Yoshiaki Yasuno","doi":"10.1364/BOE.564030","DOIUrl":"10.1364/BOE.564030","url":null,"abstract":"<p><p>The wavelength and system-resolution dependencies of dynamic optical coherence tomography (DOCT) are investigated experimentally and numerically. Experimental investigations demonstrate significant wavelength dependency for the DOCT values but no marked resolution dependency. Numerical simulations were performed using diffusion, random-ballistic motion, and mono-directional flow-based motion models. Diffusion and random-ballistic motion-based simulations show significant wavelength dependency. Additionally, these simulations revealed a small but certain resolution dependency. Mono-directional flow simulations did not show wavelength dependency but did demonstrate resolution dependency. The DOCT value is sensitive to both tissue dynamics and the OCT system specification. These effects should be considered when interpreting DOCT images.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3084-3104"},"PeriodicalIF":3.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joel A Bellesini, Ken Y Foo, Jiayue Li, Rowan W Sanderson, Renate Zilkens, Laura Gale, Mireille Hardie, Saud Hamza, Anmol Rijhumal, Christobel M Saunders, Brendan F Kennedy
{"title":"Three-dimensional dynamic optical coherence tomography for breast tumor margin assessment.","authors":"Joel A Bellesini, Ken Y Foo, Jiayue Li, Rowan W Sanderson, Renate Zilkens, Laura Gale, Mireille Hardie, Saud Hamza, Anmol Rijhumal, Christobel M Saunders, Brendan F Kennedy","doi":"10.1364/BOE.563044","DOIUrl":"10.1364/BOE.563044","url":null,"abstract":"<p><p>Intraoperative margin assessment techniques are needed to reduce the re-excision rate in breast-conserving surgery. Optical coherence tomography (OCT) is a non-invasive imaging technique capable of rapid three-dimensional (3-D) imaging of the internal microstructure of tissues. However, there is often low contrast between morphological features in breast tissue. Dynamic OCT (d-OCT), which provides additional contrast derived from the temporal variance of the OCT signal caused by intrinsic motion within the tissue, may provide a solution. However, few studies have applied it to breast tumor margin assessment. In this study, we acquired 3-D d-OCT images of ten human mastectomy specimens and three wide local excisions from breast-conserving surgery (BCS) procedures and, in each case, performed co-registered histology for validation. To optimize the trade-off between spatial resolution, temporal resolution, and acquisition time, we considered a range of acquisition settings. Several methods for visualizing d-OCT images were investigated, including Fourier weighted mean frequency, Fourier power spectral analysis, using red-green-blue (RGB) and hue-saturation-value (HSV) color spaces, and phase variance. We present d-OCT images of invasive ductal carcinoma (IDC), ductal carcinoma <i>in situ</i> (DCIS), invasive lobular carcinoma (ILC), and lobular carcinoma <i>in situ</i> (LCIS), and show that the contrast between malignant and benign regions is consistently higher with d-OCT than using OCT intensity alone. The improved contrast may derive from increased proliferation rates and collagen deposition in cancerous tissue compared to benign tissue. We believe that our results demonstrate that d-OCT has the potential to improve intraoperative tumor margin assessment during breast-conserving surgery.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3061-3074"},"PeriodicalIF":3.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339312/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arran Sykes, Lisa Saalbach, Sam Benson, Eleni Nestoros, Rachael Tobin, Xin Yi, Michael G Tanner, Marc Vendrell, Gerald S Buller
{"title":"Real-time detection of singlet-oxygen signatures using a single-photon avalanche diode detector.","authors":"Arran Sykes, Lisa Saalbach, Sam Benson, Eleni Nestoros, Rachael Tobin, Xin Yi, Michael G Tanner, Marc Vendrell, Gerald S Buller","doi":"10.1364/BOE.568337","DOIUrl":"10.1364/BOE.568337","url":null,"abstract":"<p><p>Singlet-oxygen, the first excited state of molecular oxygen (O<sub>2</sub>), is a reactive oxygen species that plays a key role as a cytotoxic agent in photodynamic therapy (PDT). In this work, we report a highly light-sensitive detection system based on a single-photon avalanche diode (SPAD) detector and time-correlated single-photon counting (TCPSC) for real-time detection of luminescence signatures from photosensitized singlet-oxygen. Dynamics of singlet-oxygen produced by the excitation of small-scale organic nitrobenzoselenadiazole photosensitizers were extracted with acquisition times as short as 1 second. In a clinical setting, the ability to detect singlet-oxygen production in short time frames could allow for real-time adjustments in light dosing, ensuring sufficient singlet-oxygen production and complete treatment of diseased tissue in applications such as PDT.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3075-3083"},"PeriodicalIF":3.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339314/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Szymon Tamborski, Marta K Skrok, Matt S Hepburn, Mateusz Maniewski, Marek Zdrenka, Adam Kowalewski, Łukasz Szylberg, Brendan F Kennedy
{"title":"Wide-field quantitative micro-elastography of freshly excised human prostate.","authors":"Szymon Tamborski, Marta K Skrok, Matt S Hepburn, Mateusz Maniewski, Marek Zdrenka, Adam Kowalewski, Łukasz Szylberg, Brendan F Kennedy","doi":"10.1364/BOE.563310","DOIUrl":"10.1364/BOE.563310","url":null,"abstract":"<p><p>Prostate cancer is a significant global health issue. To advance diagnostic and treatment procedures, such as image-guided needle biopsy, optical imaging methods offering high spatial resolution have been proposed. Optical coherence tomography (OCT) allows for detailed visualization of prostate microarchitecture in three dimensions; however, it does not reliably differentiate tumors from surrounding healthy tissue. In this study, we use wide-field quantitative micro-elastography (QME) to image the micro-scale mechanical properties of freshly excised human prostate to provide additional contrast of tumor, which is known to exhibit increased stiffness. In our approach, we generate volumetric OCT, strain, and elasticity images over a field-of-view (<i>x</i> × <i>y</i> × <i>z</i>) of 46 × 46 × 1 mm<sup>3</sup>. We validate the contrast obtained in our images through co-registration with standard histology images.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3027-3046"},"PeriodicalIF":3.2,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339301/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effectiveness of digital dispersion compensation in OCT.","authors":"Fengquan Liu, Xingde Li","doi":"10.1364/BOE.567257","DOIUrl":"10.1364/BOE.567257","url":null,"abstract":"<p><p>Dispersion mismatch in optical coherence tomography (OCT) is typically addressed through either physical or digital compensation. In this study, we investigate the impact of dispersion on OCT detection sensitivity and compare the effectiveness of physical and digital compensation across varying degrees of dispersion mismatch. Our results demonstrate that while digital dispersion compensation can effectively restore detection sensitivity, its efficacy is constrained by the severity of the dispersion mismatch. Beyond a certain threshold, digital compensation fails to fully recover image information, leading to degradation in image quality.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3017-3026"},"PeriodicalIF":3.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339299/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ariane Garrett, Byungchan Kim, Nil Z Gurel, Edbert J Sie, Benjamin K Wilson, Francesco Marsili, John P Forman, Naomi M Hamburg, David A Boas, Darren Roblyer
{"title":"Speckle contrast optical spectroscopy for cuffless blood pressure estimation based on microvascular blood flow and volume oscillations.","authors":"Ariane Garrett, Byungchan Kim, Nil Z Gurel, Edbert J Sie, Benjamin K Wilson, Francesco Marsili, John P Forman, Naomi M Hamburg, David A Boas, Darren Roblyer","doi":"10.1364/BOE.560022","DOIUrl":"10.1364/BOE.560022","url":null,"abstract":"<p><p>This work introduces high-speed (390 Hz) speckle contrast optical spectroscopy (SCOS) to enable simultaneous measurements of multi-anatomic site microvascular blood volume and flow oscillations. Simultaneous blood flow and volume waveforms were extracted at two wavelengths on the wrist and finger, in reflectance and transmission mode, respectively. Blood volume changes (also known as photoplethysmography, or PPG) were determined based on intensity oscillations. Blood flow information was determined based on dynamic light scattering information encoded in the 2D spatial speckle pattern after removal of stochastic and instrument noise. We extracted a wide array of temporal, shape-based, and frequency-domain features from each high-resolution waveform, as well as features that characterize the temporal relationships between these features. These features and their inter-relationships are determined by the dynamic biomechanical properties of peripheral microvasculature, including vascular compliance and resistance, which are key determinants of dynamic changes in systemic blood pressure (BP). In comparison to PPG alone, SCOS demonstrated a notable 31% improvement (p = 3.45 * 10<sup>-7</sup>) in systolic BP estimation when integrated into subject-specific machine-learning models. The resulting errors were remarkably low (systolic BP: 0.06+/- 2.88 mmHg, diastolic BP: 0.09 +/-2.14 mmHg) across a wide range of BP variations (range SBP: 89-284 mmHg). This improvement was sustained several weeks later within a re-measured cohort, indicating highly robust BP predictions. Looking ahead, high-speed SCOS holds the potential to substantially enhance the non-invasive characterization of the cardiovascular system, including continuous and non-invasive BP measurements, which are a long-sought-after goal of the biomedical community.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 8","pages":"3004-3016"},"PeriodicalIF":3.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12339296/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144844343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magdalena Asejczyk, Linda Lundström, Brian Vohnsen, Mircea Mujat, Minchen Wei
{"title":"Visual and Physiological Optics: introduction to the joint feature issue in <i>Biomedical Optics Express and Journal of the Optical Society of America A</i>.","authors":"Magdalena Asejczyk, Linda Lundström, Brian Vohnsen, Mircea Mujat, Minchen Wei","doi":"10.1364/BOE.569342","DOIUrl":"10.1364/BOE.569342","url":null,"abstract":"<p><p>This feature issue presents a collection of articles from the 12th Visual and Physiological Optics Meeting (VPO 2024), held August 28-30, 2024, in Wrocław, Poland. Jointly published by <i>Biomedical Optics Express</i> and the <i>Journal of the Optical Society of America A</i>, this issue highlights the wide range of topics discussed at the meeting and showcases current advancements in the field.</p>","PeriodicalId":8969,"journal":{"name":"Biomedical optics express","volume":"16 7","pages":"3001-3003"},"PeriodicalIF":2.9,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12265596/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}